Objective C Second Alpha Drop

- Style fixups in the code.
- map<> serialization fixes and more tests.
- Autocreation of map<> fields (to match repeated fields).
- @@protoc_insertion_point(global_scope|imports).
- Fixup proto2 syntax extension support.
- Move all startup code to +initialize so it happen on class usage and not app startup.
- Have generated headers use forward declarations and move imports into generated code, reduces what is need at compile time to speed up compiled and avoid pointless rippling of rebuilds.

73 files changed, 5865 insertions, 1150 deletions

diff --git a/objectivec/DevTools/check_version_stamps.sh b/objectivec/DevTools/check_version_stamps.sh
index 7fc44265..325b71dd 100755
--- a/objectivec/DevTools/check_version_stamps.sh
+++ b/objectivec/DevTools/check_version_stamps.sh
@@ -29,7 +29,7 @@ readonly PluginVersion=$( \
 )
 
 if [[ -z "${PluginVersion}" ]] ; then
-    die "Failed to fine ${ConstantName} in the plugin source (${PluginSrc})."
+    die "Failed to find ${ConstantName} in the plugin source (${PluginSrc})."
 fi
 
 # Collect version from runtime sources.
@@ -41,7 +41,7 @@ readonly RuntimeVersion=$( \
 )
 
 if [[ -z "${RuntimeVersion}" ]] ; then
-    die "Failed to fine ${ConstantName} in the runtime source (${RuntimeSrc})."
+    die "Failed to find ${ConstantName} in the runtime source (${RuntimeSrc})."
 fi
 
 # Compare them.
diff --git a/objectivec/DevTools/full_mac_build.sh b/objectivec/DevTools/full_mac_build.sh
new file mode 100755
index 00000000..57c4f438
--- /dev/null
+++ b/objectivec/DevTools/full_mac_build.sh
@@ -0,0 +1,228 @@
+#!/bin/bash
+#
+# Helper to do build so you don't have to remember all the steps/args.
+
+
+set -eu
+
+# Some base locations.
+readonly ScriptDir=$(dirname "$(echo $0 | sed -e "s,^\([^/]\),$(pwd)/\1,")")
+readonly ProtoRootDir="${ScriptDir}/../.."
+
+printUsage() {
+  NAME=$(basename "${0}")
+  cat << EOF
+usage: ${NAME} [OPTIONS]
+
+This script does the common build steps needed.
+
+OPTIONS:
+
+ General:
+
+   -h, --help
+         Show this message
+   -c, --clean
+         Issue a clean before the normal build.
+   -a, --autogen
+         Start by rerunning autogen & configure.
+   -r, --regenerate-descriptors
+         The descriptor.proto is checked in generated, cause it to regenerate.
+   -j #, --jobs #
+         Force the number of parallel jobs (useful for debugging build issues).
+   --skip-xcode
+         Skip the invoke of Xcode to test the runtime on both iOS and OS X.
+   --skip-xcode-ios
+         Skip the invoke of Xcode to test the runtime on iOS.
+   --skip-xcode-osx
+         Skip the invoke of Xcode to test the runtime on OS X.
+
+EOF
+}
+
+header() {
+  echo ""
+  echo "========================================================================"
+  echo "    ${@}"
+  echo "========================================================================"
+}
+
+# Thanks to libtool, builds can fail in odd ways and since it eats some output
+# it can be hard to spot, so force error output if make exits with a non zero.
+wrapped_make() {
+  set +e  # Don't stop if the command fails.
+  make $*
+  MAKE_EXIT_STATUS=$?
+  if [ ${MAKE_EXIT_STATUS} -ne 0 ]; then
+    echo "Error: 'make $*' exited with status ${MAKE_EXIT_STATUS}"
+    exit ${MAKE_EXIT_STATUS}
+  fi
+  set -e
+}
+
+NUM_MAKE_JOBS=$(/usr/sbin/sysctl -n hw.ncpu)
+if [[ "${NUM_MAKE_JOBS}" -lt 4 ]] ; then
+  NUM_MAKE_JOBS=4
+fi
+
+DO_AUTOGEN=no
+DO_CLEAN=no
+REGEN_CPP_DESCRIPTORS=no
+DO_XCODE_IOS_TESTS=yes
+DO_XCODE_OSX_TESTS=yes
+while [[ $# != 0 ]]; do
+  case "${1}" in
+    -h | --help )
+      printUsage
+      exit 0
+      ;;
+    -c | --clean )
+      DO_CLEAN=yes
+      ;;
+    -a | --autogen )
+      DO_AUTOGEN=yes
+      ;;
+    -r | --regenerate-cpp-descriptors )
+      REGEN_CPP_DESCRIPTORS=yes
+      ;;
+    -j | --jobs )
+      shift
+      NUM_MAKE_JOBS="${1}"
+      ;;
+    --skip-xcode )
+      DO_XCODE_IOS_TESTS=no
+      DO_XCODE_OSX_TESTS=no
+      ;;
+    --skip-xcode-ios )
+      DO_XCODE_IOS_TESTS=no
+      ;;
+    --skip-xcode-osx )
+      DO_XCODE_OSX_TESTS=no
+      ;;
+    -*)
+      echo "ERROR: Unknown option: ${1}" 1>&2
+      printUsage
+      exit 1
+      ;;
+    *)
+      echo "ERROR: Unknown argument: ${1}" 1>&2
+      printUsage
+      exit 1
+      ;;
+  esac
+  shift
+done
+
+# Into the proto dir.
+pushd "${ProtoRootDir}"
+
+# if no Makefile, force the autogen.
+if [[ ! -f Makefile ]] ; then
+  DO_AUTOGEN=yes
+fi
+
+if [[ "${DO_AUTOGEN}" == "yes" ]] ; then
+  header "Running autogen & configure"
+  ./autogen.sh
+  ./configure CXXFLAGS="-mmacosx-version-min=10.9 -Wnon-virtual-dtor -Woverloaded-virtual -Wunused-const-variable -Wunused-function"
+fi
+
+if [[ "${DO_CLEAN}" == "yes" ]] ; then
+  header "Cleaning"
+  wrapped_make clean
+  if [[ "${DO_XCODE_IOS_TESTS}" == "yes" ]] ; then
+    XCODEBUILD_CLEAN_BASE_IOS=(
+      xcodebuild
+        -project objectivec/ProtocolBuffers_iOS.xcodeproj
+        -scheme ProtocolBuffers
+    )
+  "${XCODEBUILD_CLEAN_BASE_IOS[@]}" -configuration Debug clean
+  "${XCODEBUILD_CLEAN_BASE_IOS[@]}" -configuration Release clean
+  fi
+  if [[ "${DO_XCODE_OSX_TESTS}" == "yes" ]] ; then
+    XCODEBUILD_CLEAN_BASE_OSX=(
+      xcodebuild
+        -project objectivec/ProtocolBuffers_OSX.xcodeproj
+        -scheme ProtocolBuffers
+    )
+  "${XCODEBUILD_CLEAN_BASE_OSX[@]}" -configuration Debug clean
+  "${XCODEBUILD_CLEAN_BASE_OSX[@]}" -configuration Release clean
+  fi
+fi
+
+if [[ "${REGEN_CPP_DESCRIPTORS}" == "yes" ]] ; then
+  header "Regenerating the C++ descriptor sources."
+  ./generate_descriptor_proto.sh -j "${NUM_MAKE_JOBS}"
+fi
+
+header "Building"
+# Can't issue these together, when fully parallel, something sometimes chokes
+# at random.
+wrapped_make -j "${NUM_MAKE_JOBS}" all
+wrapped_make -j "${NUM_MAKE_JOBS}" check
+
+header "Ensuring the ObjC descriptors are current."
+# Find the newest input file (protos, compiler, and this script).
+# (these patterns catch some extra stuff, but better to over sample than under)
+readonly NewestInput=$(find \
+   src/google/protobuf/*.proto \
+   src/.libs src/*.la src/protoc \
+   objectivec/generate_descriptors_proto.sh \
+      -type f -print0 \
+      | xargs -0 stat -f "%m %N" \
+      | sort -n | tail -n1 | cut -f2- -d" ")
+# Find the oldest output file.
+readonly OldestOutput=$(find \
+      "${ProtoRootDir}/objectivec/google" \
+      -type f -print0 \
+      | xargs -0 stat -f "%m %N" \
+      | sort -n -r | tail -n1 | cut -f2- -d" ")
+# If the newest input is newer than the oldest output, regenerate.
+if [[ "${NewestInput}" -nt "${OldestOutput}" ]] ; then
+  echo ">> Newest input is newer than oldest output, regenerating."
+  objectivec/generate_descriptors_proto.sh -j "${NUM_MAKE_JOBS}"
+else
+  echo ">> Newest input is older than oldest output, no need to regenerating."
+fi
+
+header "Checking on the ObjC Runtime Code"
+objectivec/DevTools/pddm_tests.py
+if ! objectivec/DevTools/pddm.py --dry-run objectivec/*.[hm] objectivec/Tests/*.[hm] ; then
+  echo ""
+  echo "Update by running:"
+  echo "   objectivec/DevTools/pddm.py objectivec/*.[hm] objectivec/Tests/*.[hm]"
+  exit 1
+fi
+
+if [[ "${DO_XCODE_IOS_TESTS}" == "yes" ]] ; then
+  XCODEBUILD_TEST_BASE_IOS=(
+    xcodebuild
+      -project objectivec/ProtocolBuffers_iOS.xcodeproj
+      -scheme ProtocolBuffers
+      # Don't need to worry about form factors or retina/non retina;
+      # just pick a mix of OS Versions and 32/64 bit.
+      -destination "platform=iOS Simulator,name=iPhone 4s,OS=7.1" # 32bit
+      -destination "platform=iOS Simulator,name=iPhone 6,OS=8.3" # 64bit
+      -destination "platform=iOS Simulator,name=iPad 2,OS=7.1" # 32bit
+      -destination "platform=iOS Simulator,name=iPad Air,OS=8.3" # 64bit
+  )
+  header "Doing Xcode iOS build/tests - Debug"
+  "${XCODEBUILD_TEST_BASE_IOS[@]}" -configuration Debug test
+  header "Doing Xcode iOS build/tests - Release"
+  "${XCODEBUILD_TEST_BASE_IOS[@]}" -configuration Release test
+  # Don't leave the simulator in the developer's face.
+  killall "iOS Simulator"
+fi
+if [[ "${DO_XCODE_OSX_TESTS}" == "yes" ]] ; then
+  XCODEBUILD_TEST_BASE_OSX=(
+    xcodebuild
+      -project objectivec/ProtocolBuffers_OSX.xcodeproj
+      -scheme ProtocolBuffers
+      # Since the ObjC 2.0 Runtime is required, 32bit OS X isn't supported.
+      -destination "platform=OS X,arch=x86_64" # 64bit
+  )
+  header "Doing Xcode OS X build/tests - Debug"
+  "${XCODEBUILD_TEST_BASE_OSX[@]}" -configuration Debug test
+  header "Doing Xcode OS X build/tests - Release"
+  "${XCODEBUILD_TEST_BASE_OSX[@]}" -configuration Release test
+fi
diff --git a/objectivec/DevTools/generate_descriptors_proto.sh b/objectivec/DevTools/generate_descriptors_proto.sh
deleted file mode 100755
index 42502bfe..00000000
--- a/objectivec/DevTools/generate_descriptors_proto.sh
+++ /dev/null
@@ -1,36 +0,0 @@
-#!/bin/bash
-
-# This script will generate the common descriptors needed by the Objective C
-# runtime.
-
-# HINT:  Flags passed to generate_descriptor_proto.sh will be passed directly
-#   to make when building protoc.  This is particularly useful for passing
-#   -j4 to run 4 jobs simultaneously.
-
-set -eu
-
-readonly ScriptDir=$(dirname "$(echo $0 | sed -e "s,^\([^/]\),$(pwd)/\1,")")
-readonly ProtoRootDir="${ScriptDir}/../.."
-readonly ProtoC="${ProtoRootDir}/src/protoc"
-
-pushd "${ProtoRootDir}" > /dev/null
-
-# Compiler build fails if config.h hasn't been made yet (even if configure/etc.
-# have been run, so get that made first).
-make $@ config.h
-
-# Make sure the compiler is current.
-cd src
-make $@ protoc
-
-# These really should only be run when the inputs or compiler are newer than
-# the outputs.
-
-# Needed by the runtime.
-./protoc --objc_out="${ProtoRootDir}/objectivec" google/protobuf/descriptor.proto
-
-# Well known types that the library provides helpers for.
-./protoc --objc_out="${ProtoRootDir}/objectivec" google/protobuf/timestamp.proto
-./protoc --objc_out="${ProtoRootDir}/objectivec" google/protobuf/duration.proto
-
-popd > /dev/null
diff --git a/objectivec/GPBArray.m b/objectivec/GPBArray.m
index 6aa3df2e..60b08ad1 100644
--- a/objectivec/GPBArray.m
+++ b/objectivec/GPBArray.m
@@ -149,7 +149,9 @@ static BOOL ArrayDefault_IsValidValue(int32_t value) {
 
 //%PDDM-DEFINE ARRAY_IMMUTABLE_CORE(NAME, TYPE, ACCESSOR_NAME, FORMAT)
 //%- (void)dealloc {
-//%  NSAssert(!_autocreator, @"Autocreator must be cleared before release.");
+//%  NSAssert(!_autocreator,
+//%           @"%@: Autocreator must be cleared before release, autocreator: %@",
+//%           [self class], _autocreator);
 //%  free(_values);
 //%  [super dealloc];
 //%}
@@ -214,7 +216,7 @@ static BOOL ArrayDefault_IsValidValue(int32_t value) {
 //%  if (values == NULL || count == 0) return;
 //%MUTATION_HOOK_##HOOK_1()  NSUInteger initialCount = _count;
 //%  NSUInteger newCount = initialCount + count;
-//%MAYBE_GROW_TO_SET_COUNT(newCount);
+//%MAYBE_GROW_TO_SET_COUNT(newCount)
 //%  memcpy(&_values[initialCount], values, count * sizeof(TYPE));
 //%  if (_autocreator) {
 //%    GPBAutocreatedArrayModified(_autocreator, self);
@@ -225,7 +227,7 @@ static BOOL ArrayDefault_IsValidValue(int32_t value) {
 //%VALIDATE_RANGE(index, _count + 1)
 //%MUTATION_HOOK_##HOOK_2()  NSUInteger initialCount = _count;
 //%  NSUInteger newCount = initialCount + 1;
-//%MAYBE_GROW_TO_SET_COUNT(newCount);
+//%MAYBE_GROW_TO_SET_COUNT(newCount)
 //%  if (index != initialCount) {
 //%    memmove(&_values[index + 1], &_values[index], (initialCount - index) * sizeof(TYPE));
 //%  }
@@ -355,7 +357,9 @@ static BOOL ArrayDefault_IsValidValue(int32_t value) {
 }
 
 - (void)dealloc {
-  NSAssert(!_autocreator, @"Autocreator must be cleared before release.");
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   free(_values);
   [super dealloc];
 }
@@ -442,7 +446,7 @@ static BOOL ArrayDefault_IsValidValue(int32_t value) {
   if (newCount > _capacity) {
     [self internalResizeToCapacity:CapacityFromCount(newCount)];
   }
-  _count = newCount;;
+  _count = newCount;
   memcpy(&_values[initialCount], values, count * sizeof(int32_t));
   if (_autocreator) {
     GPBAutocreatedArrayModified(_autocreator, self);
@@ -460,7 +464,7 @@ static BOOL ArrayDefault_IsValidValue(int32_t value) {
   if (newCount > _capacity) {
     [self internalResizeToCapacity:CapacityFromCount(newCount)];
   }
-  _count = newCount;;
+  _count = newCount;
   if (index != initialCount) {
     memmove(&_values[index + 1], &_values[index], (initialCount - index) * sizeof(int32_t));
   }
@@ -598,7 +602,9 @@ static BOOL ArrayDefault_IsValidValue(int32_t value) {
 }
 
 - (void)dealloc {
-  NSAssert(!_autocreator, @"Autocreator must be cleared before release.");
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   free(_values);
   [super dealloc];
 }
@@ -685,7 +691,7 @@ static BOOL ArrayDefault_IsValidValue(int32_t value) {
   if (newCount > _capacity) {
     [self internalResizeToCapacity:CapacityFromCount(newCount)];
   }
-  _count = newCount;;
+  _count = newCount;
   memcpy(&_values[initialCount], values, count * sizeof(uint32_t));
   if (_autocreator) {
     GPBAutocreatedArrayModified(_autocreator, self);
@@ -703,7 +709,7 @@ static BOOL ArrayDefault_IsValidValue(int32_t value) {
   if (newCount > _capacity) {
     [self internalResizeToCapacity:CapacityFromCount(newCount)];
   }
-  _count = newCount;;
+  _count = newCount;
   if (index != initialCount) {
     memmove(&_values[index + 1], &_values[index], (initialCount - index) * sizeof(uint32_t));
   }
@@ -841,7 +847,9 @@ static BOOL ArrayDefault_IsValidValue(int32_t value) {
 }
 
 - (void)dealloc {
-  NSAssert(!_autocreator, @"Autocreator must be cleared before release.");
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   free(_values);
   [super dealloc];
 }
@@ -928,7 +936,7 @@ static BOOL ArrayDefault_IsValidValue(int32_t value) {
   if (newCount > _capacity) {
     [self internalResizeToCapacity:CapacityFromCount(newCount)];
   }
-  _count = newCount;;
+  _count = newCount;
   memcpy(&_values[initialCount], values, count * sizeof(int64_t));
   if (_autocreator) {
     GPBAutocreatedArrayModified(_autocreator, self);
@@ -946,7 +954,7 @@ static BOOL ArrayDefault_IsValidValue(int32_t value) {
   if (newCount > _capacity) {
     [self internalResizeToCapacity:CapacityFromCount(newCount)];
   }
-  _count = newCount;;
+  _count = newCount;
   if (index != initialCount) {
     memmove(&_values[index + 1], &_values[index], (initialCount - index) * sizeof(int64_t));
   }
@@ -1084,7 +1092,9 @@ static BOOL ArrayDefault_IsValidValue(int32_t value) {
 }
 
 - (void)dealloc {
-  NSAssert(!_autocreator, @"Autocreator must be cleared before release.");
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   free(_values);
   [super dealloc];
 }
@@ -1171,7 +1181,7 @@ static BOOL ArrayDefault_IsValidValue(int32_t value) {
   if (newCount > _capacity) {
     [self internalResizeToCapacity:CapacityFromCount(newCount)];
   }
-  _count = newCount;;
+  _count = newCount;
   memcpy(&_values[initialCount], values, count * sizeof(uint64_t));
   if (_autocreator) {
     GPBAutocreatedArrayModified(_autocreator, self);
@@ -1189,7 +1199,7 @@ static BOOL ArrayDefault_IsValidValue(int32_t value) {
   if (newCount > _capacity) {
     [self internalResizeToCapacity:CapacityFromCount(newCount)];
   }
-  _count = newCount;;
+  _count = newCount;
   if (index != initialCount) {
     memmove(&_values[index + 1], &_values[index], (initialCount - index) * sizeof(uint64_t));
   }
@@ -1327,7 +1337,9 @@ static BOOL ArrayDefault_IsValidValue(int32_t value) {
 }
 
 - (void)dealloc {
-  NSAssert(!_autocreator, @"Autocreator must be cleared before release.");
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   free(_values);
   [super dealloc];
 }
@@ -1414,7 +1426,7 @@ static BOOL ArrayDefault_IsValidValue(int32_t value) {
   if (newCount > _capacity) {
     [self internalResizeToCapacity:CapacityFromCount(newCount)];
   }
-  _count = newCount;;
+  _count = newCount;
   memcpy(&_values[initialCount], values, count * sizeof(float));
   if (_autocreator) {
     GPBAutocreatedArrayModified(_autocreator, self);
@@ -1432,7 +1444,7 @@ static BOOL ArrayDefault_IsValidValue(int32_t value) {
   if (newCount > _capacity) {
     [self internalResizeToCapacity:CapacityFromCount(newCount)];
   }
-  _count = newCount;;
+  _count = newCount;
   if (index != initialCount) {
     memmove(&_values[index + 1], &_values[index], (initialCount - index) * sizeof(float));
   }
@@ -1570,7 +1582,9 @@ static BOOL ArrayDefault_IsValidValue(int32_t value) {
 }
 
 - (void)dealloc {
-  NSAssert(!_autocreator, @"Autocreator must be cleared before release.");
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   free(_values);
   [super dealloc];
 }
@@ -1657,7 +1671,7 @@ static BOOL ArrayDefault_IsValidValue(int32_t value) {
   if (newCount > _capacity) {
     [self internalResizeToCapacity:CapacityFromCount(newCount)];
   }
-  _count = newCount;;
+  _count = newCount;
   memcpy(&_values[initialCount], values, count * sizeof(double));
   if (_autocreator) {
     GPBAutocreatedArrayModified(_autocreator, self);
@@ -1675,7 +1689,7 @@ static BOOL ArrayDefault_IsValidValue(int32_t value) {
   if (newCount > _capacity) {
     [self internalResizeToCapacity:CapacityFromCount(newCount)];
   }
-  _count = newCount;;
+  _count = newCount;
   if (index != initialCount) {
     memmove(&_values[index + 1], &_values[index], (initialCount - index) * sizeof(double));
   }
@@ -1813,7 +1827,9 @@ static BOOL ArrayDefault_IsValidValue(int32_t value) {
 }
 
 - (void)dealloc {
-  NSAssert(!_autocreator, @"Autocreator must be cleared before release.");
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   free(_values);
   [super dealloc];
 }
@@ -1900,7 +1916,7 @@ static BOOL ArrayDefault_IsValidValue(int32_t value) {
   if (newCount > _capacity) {
     [self internalResizeToCapacity:CapacityFromCount(newCount)];
   }
-  _count = newCount;;
+  _count = newCount;
   memcpy(&_values[initialCount], values, count * sizeof(BOOL));
   if (_autocreator) {
     GPBAutocreatedArrayModified(_autocreator, self);
@@ -1918,7 +1934,7 @@ static BOOL ArrayDefault_IsValidValue(int32_t value) {
   if (newCount > _capacity) {
     [self internalResizeToCapacity:CapacityFromCount(newCount)];
   }
-  _count = newCount;;
+  _count = newCount;
   if (index != initialCount) {
     memmove(&_values[index + 1], &_values[index], (initialCount - index) * sizeof(BOOL));
   }
@@ -2083,7 +2099,9 @@ static BOOL ArrayDefault_IsValidValue(int32_t value) {
 // This block of code is generated, do not edit it directly.
 
 - (void)dealloc {
-  NSAssert(!_autocreator, @"Autocreator must be cleared before release.");
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   free(_values);
   [super dealloc];
 }
@@ -2229,7 +2247,7 @@ static BOOL ArrayDefault_IsValidValue(int32_t value) {
   if (newCount > _capacity) {
     [self internalResizeToCapacity:CapacityFromCount(newCount)];
   }
-  _count = newCount;;
+  _count = newCount;
   memcpy(&_values[initialCount], values, count * sizeof(int32_t));
   if (_autocreator) {
     GPBAutocreatedArrayModified(_autocreator, self);
@@ -2247,7 +2265,7 @@ static BOOL ArrayDefault_IsValidValue(int32_t value) {
   if (newCount > _capacity) {
     [self internalResizeToCapacity:CapacityFromCount(newCount)];
   }
-  _count = newCount;;
+  _count = newCount;
   if (index != initialCount) {
     memmove(&_values[index + 1], &_values[index], (initialCount - index) * sizeof(int32_t));
   }
@@ -2332,7 +2350,7 @@ static BOOL ArrayDefault_IsValidValue(int32_t value) {
   if (newCount > _capacity) {
     [self internalResizeToCapacity:CapacityFromCount(newCount)];
   }
-  _count = newCount;;
+  _count = newCount;
   memcpy(&_values[initialCount], values, count * sizeof(int32_t));
   if (_autocreator) {
     GPBAutocreatedArrayModified(_autocreator, self);
@@ -2355,7 +2373,7 @@ static BOOL ArrayDefault_IsValidValue(int32_t value) {
   if (newCount > _capacity) {
     [self internalResizeToCapacity:CapacityFromCount(newCount)];
   }
-  _count = newCount;;
+  _count = newCount;
   if (index != initialCount) {
     memmove(&_values[index + 1], &_values[index], (initialCount - index) * sizeof(int32_t));
   }
@@ -2407,7 +2425,9 @@ static BOOL ArrayDefault_IsValidValue(int32_t value) {
 }
 
 - (void)dealloc {
-  NSAssert(!_autocreator, @"Autocreator must be cleared before release.");
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_array release];
   [super dealloc];
 }
diff --git a/objectivec/GPBBootstrap.h b/objectivec/GPBBootstrap.h
index 530eb5cb..3dd2de83 100644
--- a/objectivec/GPBBootstrap.h
+++ b/objectivec/GPBBootstrap.h
@@ -51,11 +51,11 @@
 // the Swift bridge will have one where the names line up to support short
 // names since they are scoped to the enum.
 // https://developer.apple.com/library/ios/documentation/Swift/Conceptual/BuildingCocoaApps/InteractingWithCAPIs.html#//apple_ref/doc/uid/TP40014216-CH8-XID_11
-#define GPB_ENUM(X) enum X##_ : int32_t X; typedef NS_ENUM(int32_t, X##_)
-// GPB_ENUM_FWD_DECLARE is used for forward declaring enums ex:
+#define GPB_ENUM(X) NS_ENUM(int32_t, X)
+// GPB_ENUM_FWD_DECLARE is used for forward declaring enums, ex:
 //   GPB_ENUM_FWD_DECLARE(Foo_Enum)
 //   @property (nonatomic) Foo_Enum value;
-#define GPB_ENUM_FWD_DECLARE(_name) enum _name : int32_t
+#define GPB_ENUM_FWD_DECLARE(X) enum X : int32_t
 
 // Based upon CF_INLINE. Forces inlining in release.
 #if !defined(DEBUG)
diff --git a/objectivec/GPBCodedInputStream.h b/objectivec/GPBCodedInputStream.h
index db39c268..e9b27e22 100644
--- a/objectivec/GPBCodedInputStream.h
+++ b/objectivec/GPBCodedInputStream.h
@@ -66,7 +66,9 @@
 - (void)readMessage:(GPBMessage *)message
     extensionRegistry:(GPBExtensionRegistry *)extensionRegistry;
 
-// Reads and discards a single field, given its tag value.
+// Reads and discards a single field, given its tag value. Returns NO if the
+// tag is an endgroup tag, in which case nothing is skipped.  Otherwise,
+// returns YES.
 - (BOOL)skipField:(int32_t)tag;
 
 // Reads and discards an entire message.  This will read either until EOF
@@ -74,8 +76,8 @@
 - (void)skipMessage;
 
 // Verifies that the last call to readTag() returned the given tag value.
-// This is used to verify that a nested group ended with the correct
-// end tag.
+// This is used to verify that a nested group ended with the correct end tag.
+// Throws NSParseErrorException if value does not match the last tag.
 - (void)checkLastTagWas:(int32_t)value;
 
 @end
diff --git a/objectivec/GPBDescriptor.h b/objectivec/GPBDescriptor.h
index d8c369c1..97b46b3c 100644
--- a/objectivec/GPBDescriptor.h
+++ b/objectivec/GPBDescriptor.h
@@ -56,7 +56,6 @@ typedef NS_ENUM(NSInteger, GPBFieldType) {
 @property(nonatomic, readonly, strong) NSArray *fields;
 @property(nonatomic, readonly, strong) NSArray *oneofs;
 @property(nonatomic, readonly, strong) NSArray *enums;
-@property(nonatomic, readonly, strong) NSArray *extensions;
 @property(nonatomic, readonly) const GPBExtensionRange *extensionRanges;
 @property(nonatomic, readonly) NSUInteger extensionRangesCount;
 @property(nonatomic, readonly, assign) GPBFileDescriptor *file;
@@ -68,8 +67,6 @@ typedef NS_ENUM(NSInteger, GPBFieldType) {
 - (GPBFieldDescriptor *)fieldWithName:(NSString *)name;
 - (GPBOneofDescriptor *)oneofWithName:(NSString *)name;
 - (GPBEnumDescriptor *)enumWithName:(NSString *)name;
-- (GPBFieldDescriptor *)extensionWithNumber:(uint32_t)fieldNumber;
-- (GPBFieldDescriptor *)extensionWithName:(NSString *)name;
 
 @end
 
diff --git a/objectivec/GPBDescriptor.m b/objectivec/GPBDescriptor.m
index 6730d532..b955018c 100644
--- a/objectivec/GPBDescriptor.m
+++ b/objectivec/GPBDescriptor.m
@@ -93,7 +93,6 @@ static NSArray *NewFieldsArrayForHasIndex(int hasIndex,
 @implementation GPBDescriptor {
   Class messageClass_;
   NSArray *enums_;
-  NSArray *extensions_;
   GPBFileDescriptor *file_;
   BOOL wireFormat_;
 }
@@ -102,7 +101,6 @@ static NSArray *NewFieldsArrayForHasIndex(int hasIndex,
 @synthesize fields = fields_;
 @synthesize oneofs = oneofs_;
 @synthesize enums = enums_;
-@synthesize extensions = extensions_;
 @synthesize extensionRanges = extensionRanges_;
 @synthesize extensionRangesCount = extensionRangesCount_;
 @synthesize file = file_;
@@ -161,13 +159,11 @@ static NSArray *NewFieldsArrayForHasIndex(int hasIndex,
     [enums addObject:enumDescriptor];
   }
 
-  // TODO(dmaclach): Add support for extensions
   GPBDescriptor *descriptor = [[self alloc] initWithClass:messageClass
                                                      file:file
                                                    fields:fields
                                                    oneofs:oneofs
                                                     enums:enums
-                                               extensions:nil
                                           extensionRanges:ranges
                                      extensionRangesCount:rangeCount
                                               storageSize:storageSize
@@ -226,7 +222,6 @@ static NSArray *NewFieldsArrayForHasIndex(int hasIndex,
                        fields:(NSArray *)fields
                        oneofs:(NSArray *)oneofs
                         enums:(NSArray *)enums
-                   extensions:(NSArray *)extensions
               extensionRanges:(const GPBExtensionRange *)extensionRanges
          extensionRangesCount:(NSUInteger)extensionRangesCount
                   storageSize:(size_t)storageSize
@@ -237,7 +232,6 @@ static NSArray *NewFieldsArrayForHasIndex(int hasIndex,
     fields_ = [fields retain];
     oneofs_ = [oneofs retain];
     enums_ = [enums retain];
-    extensions_ = [extensions retain];
     extensionRanges_ = extensionRanges;
     extensionRangesCount_ = extensionRangesCount;
     storageSize_ = storageSize;
@@ -250,7 +244,6 @@ static NSArray *NewFieldsArrayForHasIndex(int hasIndex,
   [fields_ release];
   [oneofs_ release];
   [enums_ release];
-  [extensions_ release];
   [super dealloc];
 }
 
@@ -299,24 +292,6 @@ static NSArray *NewFieldsArrayForHasIndex(int hasIndex,
   return nil;
 }
 
-- (GPBFieldDescriptor *)extensionWithNumber:(uint32_t)fieldNumber {
-  for (GPBFieldDescriptor *descriptor in extensions_) {
-    if (GPBFieldNumber(descriptor) == fieldNumber) {
-      return descriptor;
-    }
-  }
-  return nil;
-}
-
-- (GPBFieldDescriptor *)extensionWithName:(NSString *)name {
-  for (GPBFieldDescriptor *descriptor in extensions_) {
-    if ([descriptor.name isEqual:name]) {
-      return descriptor;
-    }
-  }
-  return nil;
-}
-
 @end
 
 @implementation GPBFileDescriptor {
@@ -366,7 +341,7 @@ static NSArray *NewFieldsArrayForHasIndex(int hasIndex,
 }
 
 - (NSString *)name {
-  return [NSString stringWithUTF8String:oneofDescription_->name];
+  return @(oneofDescription_->name);
 }
 
 - (GPBFieldDescriptor *)fieldWithNumber:(uint32_t)fieldNumber {
@@ -455,7 +430,8 @@ uint32_t GPBFieldTag(GPBFieldDescriptor *self) {
                                              freeWhenDone:NO];
         GPBExtensionRegistry *registry = [rootClass extensionRegistry];
         fieldOptions_ = [[GPBFieldOptions parseFromData:optionsData
-                                      extensionRegistry:registry] retain];
+                                      extensionRegistry:registry
+                                                  error:NULL] retain];
       }
     }
 
@@ -532,7 +508,7 @@ uint32_t GPBFieldTag(GPBFieldDescriptor *self) {
 }
 
 - (NSString *)name {
-  return [NSString stringWithUTF8String:description_->name];
+  return @(description_->name);
 }
 
 - (BOOL)isRequired {
@@ -809,7 +785,7 @@ uint32_t GPBFieldTag(GPBFieldDescriptor *self) {
 
   NSString *result = nil;
   // Naming adds an underscore between enum name and value name, skip that also.
-  NSString *shortName = [NSString stringWithUTF8String:valueDescriptor->name];
+  NSString *shortName = @(valueDescriptor->name);
 
   // See if it is in the map of special format handling.
   if (extraTextFormatInfo_) {
@@ -846,7 +822,7 @@ uint32_t GPBFieldTag(GPBFieldDescriptor *self) {
 }
 
 - (NSString *)singletonName {
-  return [NSString stringWithUTF8String:description_->singletonName];
+  return @(description_->singletonName);
 }
 
 - (const char *)singletonNameC {
diff --git a/objectivec/GPBDescriptor_PackagePrivate.h b/objectivec/GPBDescriptor_PackagePrivate.h
index acb4fe70..b289a48b 100644
--- a/objectivec/GPBDescriptor_PackagePrivate.h
+++ b/objectivec/GPBDescriptor_PackagePrivate.h
@@ -186,7 +186,6 @@ typedef struct GPBExtensionDescription {
                        fields:(NSArray *)fields
                        oneofs:(NSArray *)oneofs
                         enums:(NSArray *)enums
-                   extensions:(NSArray *)extensions
               extensionRanges:(const GPBExtensionRange *)ranges
          extensionRangesCount:(NSUInteger)rangeCount
                   storageSize:(size_t)storage
diff --git a/objectivec/GPBDictionary.m b/objectivec/GPBDictionary.m
index de7347e8..3769c697 100644
--- a/objectivec/GPBDictionary.m
+++ b/objectivec/GPBDictionary.m
@@ -45,8 +45,10 @@
 // directly.
 // ------------------------------------------------------------------
 
-#define kMapKeyFieldNumber 1
-#define kMapValueFieldNumber 2
+enum {
+  kMapKeyFieldNumber = 1,
+  kMapValueFieldNumber = 2,
+};
 
 static BOOL DictDefault_IsValidValue(int32_t value) {
   // Anything but the bad value marker is allowed.
@@ -55,58 +57,62 @@ static BOOL DictDefault_IsValidValue(int32_t value) {
 
 //%PDDM-DEFINE SERIALIZE_SUPPORT_2_TYPE(VALUE_NAME, VALUE_TYPE, GPBTYPE_NAME1, GPBTYPE_NAME2)
 //%GPB_INLINE size_t ComputeDict##VALUE_NAME##FieldSize(VALUE_TYPE value, uint32_t fieldNum, GPBType wireType) {
-//%  NSCAssert((wireType == GPBType##GPBTYPE_NAME1) || (wireType == GPBType##GPBTYPE_NAME2),
-//%            @"bad type: %d", wireType);
 //%  if (wireType == GPBType##GPBTYPE_NAME1) {
 //%    return GPBCompute##GPBTYPE_NAME1##Size(fieldNum, value);
-//%  } else {  // wireType == GPBType##GPBTYPE_NAME2
+//%  } else if (wireType == GPBType##GPBTYPE_NAME2) {
 //%    return GPBCompute##GPBTYPE_NAME2##Size(fieldNum, value);
+//%  } else {
+//%    NSCAssert(NO, @"Unexpected type %d", wireType);
+//%    return 0;
 //%  }
 //%}
 //%
 //%GPB_INLINE void WriteDict##VALUE_NAME##Field(GPBCodedOutputStream *stream, VALUE_TYPE value, uint32_t fieldNum, GPBType wireType) {
-//%  NSCAssert((wireType == GPBType##GPBTYPE_NAME1) || (wireType == GPBType##GPBTYPE_NAME2),
-//%            @"bad type: %d", wireType);
 //%  if (wireType == GPBType##GPBTYPE_NAME1) {
 //%    [stream write##GPBTYPE_NAME1##:fieldNum value:value];
-//%  } else {  // wireType == GPBType##GPBTYPE_NAME2
+//%  } else if (wireType == GPBType##GPBTYPE_NAME2) {
 //%    [stream write##GPBTYPE_NAME2##:fieldNum value:value];
+//%  } else {
+//%    NSCAssert(NO, @"Unexpected type %d", wireType);
 //%  }
 //%}
 //%
 //%PDDM-DEFINE SERIALIZE_SUPPORT_3_TYPE(VALUE_NAME, VALUE_TYPE, GPBTYPE_NAME1, GPBTYPE_NAME2, GPBTYPE_NAME3)
 //%GPB_INLINE size_t ComputeDict##VALUE_NAME##FieldSize(VALUE_TYPE value, uint32_t fieldNum, GPBType wireType) {
-//%  NSCAssert((wireType == GPBType##GPBTYPE_NAME1) || (wireType == GPBType##GPBTYPE_NAME2) || (wireType == GPBType##GPBTYPE_NAME3),
-//%            @"bad type: %d", wireType);
 //%  if (wireType == GPBType##GPBTYPE_NAME1) {
 //%    return GPBCompute##GPBTYPE_NAME1##Size(fieldNum, value);
 //%  } else if (wireType == GPBType##GPBTYPE_NAME2) {
 //%    return GPBCompute##GPBTYPE_NAME2##Size(fieldNum, value);
-//%  } else {  // wireType == GPBType##GPBTYPE_NAME3
+//%  } else if (wireType == GPBType##GPBTYPE_NAME3) {
 //%    return GPBCompute##GPBTYPE_NAME3##Size(fieldNum, value);
+//%  } else {
+//%    NSCAssert(NO, @"Unexpected type %d", wireType);
+//%    return 0;
 //%  }
 //%}
 //%
 //%GPB_INLINE void WriteDict##VALUE_NAME##Field(GPBCodedOutputStream *stream, VALUE_TYPE value, uint32_t fieldNum, GPBType wireType) {
-//%  NSCAssert((wireType == GPBType##GPBTYPE_NAME1) || (wireType == GPBType##GPBTYPE_NAME2) || (wireType == GPBType##GPBTYPE_NAME3),
-//%            @"bad type: %d", wireType);
 //%  if (wireType == GPBType##GPBTYPE_NAME1) {
 //%    [stream write##GPBTYPE_NAME1##:fieldNum value:value];
 //%  } else if (wireType == GPBType##GPBTYPE_NAME2) {
 //%    [stream write##GPBTYPE_NAME2##:fieldNum value:value];
-//%  } else {  // wireType == GPBType##GPBTYPE_NAME3
+//%  } else if (wireType == GPBType##GPBTYPE_NAME3) {
 //%    [stream write##GPBTYPE_NAME3##:fieldNum value:value];
+//%  } else {
+//%    NSCAssert(NO, @"Unexpected type %d", wireType);
 //%  }
 //%}
 //%
 //%PDDM-DEFINE SIMPLE_SERIALIZE_SUPPORT(VALUE_NAME, VALUE_TYPE, VisP)
 //%GPB_INLINE size_t ComputeDict##VALUE_NAME##FieldSize(VALUE_TYPE VisP##value, uint32_t fieldNum, GPBType wireType) {
 //%  NSCAssert(wireType == GPBType##VALUE_NAME, @"bad type: %d", wireType);
+//%  #pragma unused(wireType)  // For when asserts are off in release.
 //%  return GPBCompute##VALUE_NAME##Size(fieldNum, value);
 //%}
 //%
 //%GPB_INLINE void WriteDict##VALUE_NAME##Field(GPBCodedOutputStream *stream, VALUE_TYPE VisP##value, uint32_t fieldNum, GPBType wireType) {
 //%  NSCAssert(wireType == GPBType##VALUE_NAME, @"bad type: %d", wireType);
+//%  #pragma unused(wireType)  // For when asserts are off in release.
 //%  [stream write##VALUE_NAME##:fieldNum value:value];
 //%}
 //%
@@ -125,171 +131,185 @@ static BOOL DictDefault_IsValidValue(int32_t value) {
 // This block of code is generated, do not edit it directly.
 
 GPB_INLINE size_t ComputeDictInt32FieldSize(int32_t value, uint32_t fieldNum, GPBType wireType) {
-  NSCAssert((wireType == GPBTypeInt32) || (wireType == GPBTypeSInt32) || (wireType == GPBTypeSFixed32),
-            @"bad type: %d", wireType);
   if (wireType == GPBTypeInt32) {
     return GPBComputeInt32Size(fieldNum, value);
   } else if (wireType == GPBTypeSInt32) {
     return GPBComputeSInt32Size(fieldNum, value);
-  } else {  // wireType == GPBTypeSFixed32
+  } else if (wireType == GPBTypeSFixed32) {
     return GPBComputeSFixed32Size(fieldNum, value);
+  } else {
+    NSCAssert(NO, @"Unexpected type %d", wireType);
+    return 0;
   }
 }
 
 GPB_INLINE void WriteDictInt32Field(GPBCodedOutputStream *stream, int32_t value, uint32_t fieldNum, GPBType wireType) {
-  NSCAssert((wireType == GPBTypeInt32) || (wireType == GPBTypeSInt32) || (wireType == GPBTypeSFixed32),
-            @"bad type: %d", wireType);
   if (wireType == GPBTypeInt32) {
     [stream writeInt32:fieldNum value:value];
   } else if (wireType == GPBTypeSInt32) {
     [stream writeSInt32:fieldNum value:value];
-  } else {  // wireType == GPBTypeSFixed32
+  } else if (wireType == GPBTypeSFixed32) {
     [stream writeSFixed32:fieldNum value:value];
+  } else {
+    NSCAssert(NO, @"Unexpected type %d", wireType);
   }
 }
 
 GPB_INLINE size_t ComputeDictUInt32FieldSize(uint32_t value, uint32_t fieldNum, GPBType wireType) {
-  NSCAssert((wireType == GPBTypeUInt32) || (wireType == GPBTypeFixed32),
-            @"bad type: %d", wireType);
   if (wireType == GPBTypeUInt32) {
     return GPBComputeUInt32Size(fieldNum, value);
-  } else {  // wireType == GPBTypeFixed32
+  } else if (wireType == GPBTypeFixed32) {
     return GPBComputeFixed32Size(fieldNum, value);
+  } else {
+    NSCAssert(NO, @"Unexpected type %d", wireType);
+    return 0;
   }
 }
 
 GPB_INLINE void WriteDictUInt32Field(GPBCodedOutputStream *stream, uint32_t value, uint32_t fieldNum, GPBType wireType) {
-  NSCAssert((wireType == GPBTypeUInt32) || (wireType == GPBTypeFixed32),
-            @"bad type: %d", wireType);
   if (wireType == GPBTypeUInt32) {
     [stream writeUInt32:fieldNum value:value];
-  } else {  // wireType == GPBTypeFixed32
+  } else if (wireType == GPBTypeFixed32) {
     [stream writeFixed32:fieldNum value:value];
+  } else {
+    NSCAssert(NO, @"Unexpected type %d", wireType);
   }
 }
 
 GPB_INLINE size_t ComputeDictInt64FieldSize(int64_t value, uint32_t fieldNum, GPBType wireType) {
-  NSCAssert((wireType == GPBTypeInt64) || (wireType == GPBTypeSInt64) || (wireType == GPBTypeSFixed64),
-            @"bad type: %d", wireType);
   if (wireType == GPBTypeInt64) {
     return GPBComputeInt64Size(fieldNum, value);
   } else if (wireType == GPBTypeSInt64) {
     return GPBComputeSInt64Size(fieldNum, value);
-  } else {  // wireType == GPBTypeSFixed64
+  } else if (wireType == GPBTypeSFixed64) {
     return GPBComputeSFixed64Size(fieldNum, value);
+  } else {
+    NSCAssert(NO, @"Unexpected type %d", wireType);
+    return 0;
   }
 }
 
 GPB_INLINE void WriteDictInt64Field(GPBCodedOutputStream *stream, int64_t value, uint32_t fieldNum, GPBType wireType) {
-  NSCAssert((wireType == GPBTypeInt64) || (wireType == GPBTypeSInt64) || (wireType == GPBTypeSFixed64),
-            @"bad type: %d", wireType);
   if (wireType == GPBTypeInt64) {
     [stream writeInt64:fieldNum value:value];
   } else if (wireType == GPBTypeSInt64) {
     [stream writeSInt64:fieldNum value:value];
-  } else {  // wireType == GPBTypeSFixed64
+  } else if (wireType == GPBTypeSFixed64) {
     [stream writeSFixed64:fieldNum value:value];
+  } else {
+    NSCAssert(NO, @"Unexpected type %d", wireType);
   }
 }
 
 GPB_INLINE size_t ComputeDictUInt64FieldSize(uint64_t value, uint32_t fieldNum, GPBType wireType) {
-  NSCAssert((wireType == GPBTypeUInt64) || (wireType == GPBTypeFixed64),
-            @"bad type: %d", wireType);
   if (wireType == GPBTypeUInt64) {
     return GPBComputeUInt64Size(fieldNum, value);
-  } else {  // wireType == GPBTypeFixed64
+  } else if (wireType == GPBTypeFixed64) {
     return GPBComputeFixed64Size(fieldNum, value);
+  } else {
+    NSCAssert(NO, @"Unexpected type %d", wireType);
+    return 0;
   }
 }
 
 GPB_INLINE void WriteDictUInt64Field(GPBCodedOutputStream *stream, uint64_t value, uint32_t fieldNum, GPBType wireType) {
-  NSCAssert((wireType == GPBTypeUInt64) || (wireType == GPBTypeFixed64),
-            @"bad type: %d", wireType);
   if (wireType == GPBTypeUInt64) {
     [stream writeUInt64:fieldNum value:value];
-  } else {  // wireType == GPBTypeFixed64
+  } else if (wireType == GPBTypeFixed64) {
     [stream writeFixed64:fieldNum value:value];
+  } else {
+    NSCAssert(NO, @"Unexpected type %d", wireType);
   }
 }
 
 GPB_INLINE size_t ComputeDictBoolFieldSize(BOOL value, uint32_t fieldNum, GPBType wireType) {
   NSCAssert(wireType == GPBTypeBool, @"bad type: %d", wireType);
+  #pragma unused(wireType)  // For when asserts are off in release.
   return GPBComputeBoolSize(fieldNum, value);
 }
 
 GPB_INLINE void WriteDictBoolField(GPBCodedOutputStream *stream, BOOL value, uint32_t fieldNum, GPBType wireType) {
   NSCAssert(wireType == GPBTypeBool, @"bad type: %d", wireType);
+  #pragma unused(wireType)  // For when asserts are off in release.
   [stream writeBool:fieldNum value:value];
 }
 
 GPB_INLINE size_t ComputeDictEnumFieldSize(int32_t value, uint32_t fieldNum, GPBType wireType) {
   NSCAssert(wireType == GPBTypeEnum, @"bad type: %d", wireType);
+  #pragma unused(wireType)  // For when asserts are off in release.
   return GPBComputeEnumSize(fieldNum, value);
 }
 
 GPB_INLINE void WriteDictEnumField(GPBCodedOutputStream *stream, int32_t value, uint32_t fieldNum, GPBType wireType) {
   NSCAssert(wireType == GPBTypeEnum, @"bad type: %d", wireType);
+  #pragma unused(wireType)  // For when asserts are off in release.
   [stream writeEnum:fieldNum value:value];
 }
 
 GPB_INLINE size_t ComputeDictFloatFieldSize(float value, uint32_t fieldNum, GPBType wireType) {
   NSCAssert(wireType == GPBTypeFloat, @"bad type: %d", wireType);
+  #pragma unused(wireType)  // For when asserts are off in release.
   return GPBComputeFloatSize(fieldNum, value);
 }
 
 GPB_INLINE void WriteDictFloatField(GPBCodedOutputStream *stream, float value, uint32_t fieldNum, GPBType wireType) {
   NSCAssert(wireType == GPBTypeFloat, @"bad type: %d", wireType);
+  #pragma unused(wireType)  // For when asserts are off in release.
   [stream writeFloat:fieldNum value:value];
 }
 
 GPB_INLINE size_t ComputeDictDoubleFieldSize(double value, uint32_t fieldNum, GPBType wireType) {
   NSCAssert(wireType == GPBTypeDouble, @"bad type: %d", wireType);
+  #pragma unused(wireType)  // For when asserts are off in release.
   return GPBComputeDoubleSize(fieldNum, value);
 }
 
 GPB_INLINE void WriteDictDoubleField(GPBCodedOutputStream *stream, double value, uint32_t fieldNum, GPBType wireType) {
   NSCAssert(wireType == GPBTypeDouble, @"bad type: %d", wireType);
+  #pragma unused(wireType)  // For when asserts are off in release.
   [stream writeDouble:fieldNum value:value];
 }
 
 GPB_INLINE size_t ComputeDictStringFieldSize(NSString *value, uint32_t fieldNum, GPBType wireType) {
   NSCAssert(wireType == GPBTypeString, @"bad type: %d", wireType);
+  #pragma unused(wireType)  // For when asserts are off in release.
   return GPBComputeStringSize(fieldNum, value);
 }
 
 GPB_INLINE void WriteDictStringField(GPBCodedOutputStream *stream, NSString *value, uint32_t fieldNum, GPBType wireType) {
   NSCAssert(wireType == GPBTypeString, @"bad type: %d", wireType);
+  #pragma unused(wireType)  // For when asserts are off in release.
   [stream writeString:fieldNum value:value];
 }
 
 GPB_INLINE size_t ComputeDictObjectFieldSize(id value, uint32_t fieldNum, GPBType wireType) {
-  NSCAssert((wireType == GPBTypeMessage) || (wireType == GPBTypeString) || (wireType == GPBTypeData),
-            @"bad type: %d", wireType);
   if (wireType == GPBTypeMessage) {
     return GPBComputeMessageSize(fieldNum, value);
   } else if (wireType == GPBTypeString) {
     return GPBComputeStringSize(fieldNum, value);
-  } else {  // wireType == GPBTypeData
+  } else if (wireType == GPBTypeData) {
     return GPBComputeDataSize(fieldNum, value);
+  } else {
+    NSCAssert(NO, @"Unexpected type %d", wireType);
+    return 0;
   }
 }
 
 GPB_INLINE void WriteDictObjectField(GPBCodedOutputStream *stream, id value, uint32_t fieldNum, GPBType wireType) {
-  NSCAssert((wireType == GPBTypeMessage) || (wireType == GPBTypeString) || (wireType == GPBTypeData),
-            @"bad type: %d", wireType);
   if (wireType == GPBTypeMessage) {
     [stream writeMessage:fieldNum value:value];
   } else if (wireType == GPBTypeString) {
     [stream writeString:fieldNum value:value];
-  } else {  // wireType == GPBTypeData
+  } else if (wireType == GPBTypeData) {
     [stream writeData:fieldNum value:value];
+  } else {
+    NSCAssert(NO, @"Unexpected type %d", wireType);
   }
 }
 
 //%PDDM-EXPAND-END SERIALIZE_SUPPORT_HELPERS()
 
 size_t GPBDictionaryComputeSizeInternalHelper(NSDictionary *dict, GPBFieldDescriptor *field) {
-  NSCAssert(field.mapKeyType == GPBTypeString, @"Unexpected key type");
   GPBType mapValueType = GPBGetFieldType(field);
   __block size_t result = 0;
   [dict enumerateKeysAndObjectsUsingBlock:^(NSString *key, id obj, BOOL *stop) {
@@ -319,7 +339,7 @@ void GPBDictionaryWriteToStreamInternalHelper(GPBCodedOutputStream *outputStream
 
     // Write the size and fields.
     [outputStream writeInt32NoTag:(int32_t)msgSize];
-    [outputStream writeString:kMapValueFieldNumber value:obj];
+    [outputStream writeString:kMapKeyFieldNumber value:key];
     WriteDictObjectField(outputStream, obj, kMapValueFieldNumber, mapValueType);
   }];
 }
@@ -327,6 +347,7 @@ void GPBDictionaryWriteToStreamInternalHelper(GPBCodedOutputStream *outputStream
 BOOL GPBDictionaryIsInitializedInternalHelper(NSDictionary *dict, GPBFieldDescriptor *field) {
   NSCAssert(field.mapKeyType == GPBTypeString, @"Unexpected key type");
   NSCAssert(GPBGetFieldType(field) == GPBTypeMessage, @"Unexpected value type");
+  #pragma unused(field)  // For when asserts are off in release.
   for (GPBMessage *msg in [dict objectEnumerator]) {
     if (!msg.initialized) {
       return NO;
@@ -488,8 +509,12 @@ void GPBDictionaryReadEntry(id mapDictionary,
     }
   }
 
-  if (GPBTypeIsObject(keyType)) [key.valueString release];
-  if (GPBTypeIsObject(valueType)) [value.valueString release];
+  if (GPBTypeIsObject(keyType)) {
+    [key.valueString release];
+  }
+  if (GPBTypeIsObject(valueType)) {
+    [value.valueString release];
+  }
 }
 
 //
@@ -751,6 +776,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 //%  }
 //%
 //%  [_dictionary setObject:WRAPPED##VHELPER(value) forKey:WRAPPED##KHELPER(key)];
+//%  if (_autocreator) {
+//%    GPBAutocreatedDictionaryModified(_autocreator, self);
+//%  }
 //%}
 //%
 //%@end
@@ -758,6 +786,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 
 //%PDDM-DEFINE DICTIONARY_IMMUTABLE_CORE(KEY_NAME, KEY_TYPE, KisP, VALUE_NAME, VALUE_TYPE, KHELPER, VHELPER, ACCESSOR_NAME)
 //%- (void)dealloc {
+//%  NSAssert(!_autocreator,
+//%           @"%@: Autocreator must be cleared before release, autocreator: %@",
+//%           [self class], _autocreator);
 //%  [_dictionary release];
 //%  [super dealloc];
 //%}
@@ -854,11 +885,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 //%- (void)add##ACCESSOR_NAME##EntriesFromDictionary:(GPB##KEY_NAME##VALUE_NAME##Dictionary *)otherDictionary {
 //%  if (otherDictionary) {
 //%    [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+//%    if (_autocreator) {
+//%      GPBAutocreatedDictionaryModified(_autocreator, self);
+//%    }
 //%  }
 //%}
 //%
 //%- (void)set##ACCESSOR_NAME##Value:(VALUE_TYPE)value forKey:(KEY_TYPE##KisP$S##KisP)key {
 //%  [_dictionary setObject:WRAPPED##VHELPER(value) forKey:WRAPPED##KHELPER(key)];
+//%  if (_autocreator) {
+//%    GPBAutocreatedDictionaryModified(_autocreator, self);
+//%  }
 //%}
 //%
 //%- (void)removeValueForKey:(KEY_TYPE##KisP$S##KisP)aKey {
@@ -930,7 +967,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 //%  return [self initWithValues:NULL forKeys:NULL count:0];
 //%}
 //%
-//%BOOL_DICT_DEALLOC##HELPER()- (instancetype)copyWithZone:(NSZone *)zone {
+//%BOOL_DICT_DEALLOC##HELPER()
+//%
+//%- (instancetype)copyWithZone:(NSZone *)zone {
 //%  return [[GPBBool##VALUE_NAME##Dictionary allocWithZone:zone] initWithDictionary:self];
 //%}
 //%
@@ -1158,7 +1197,14 @@ void GPBDictionaryReadEntry(id mapDictionary,
 //%  return self;
 //%}
 //%PDDM-DEFINE BOOL_DICT_DEALLOCPOD()
-// Empty
+//%#if !defined(NS_BLOCK_ASSERTIONS)
+//%- (void)dealloc {
+//%  NSAssert(!_autocreator,
+//%           @"%@: Autocreator must be cleared before release, autocreator: %@",
+//%           [self class], _autocreator);
+//%  [super dealloc];
+//%}
+//%#endif  // !defined(NS_BLOCK_ASSERTIONS)
 //%PDDM-DEFINE BOOL_DICT_W_HASPOD(IDX, REF)
 //%BOOL_DICT_HASPOD(IDX, REF)
 //%PDDM-DEFINE BOOL_DICT_HASPOD(IDX, REF)
@@ -1189,6 +1235,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 //%        _values[i] = otherDictionary->_values[i];
 //%      }
 //%    }
+//%    if (_autocreator) {
+//%      GPBAutocreatedDictionaryModified(_autocreator, self);
+//%    }
 //%  }
 //%}
 //%
@@ -1196,6 +1245,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 //%  int idx = (key ? 1 : 0);
 //%  _values[idx] = value;
 //%  _valueSet[idx] = YES;
+//%  if (_autocreator) {
+//%    GPBAutocreatedDictionaryModified(_autocreator, self);
+//%  }
 //%}
 //%
 //%- (void)removeValueForKey:(BOOL)aKey {
@@ -1333,12 +1385,13 @@ void GPBDictionaryReadEntry(id mapDictionary,
 //%}
 //%PDDM-DEFINE BOOL_DICT_DEALLOCOBJECT()
 //%- (void)dealloc {
+//%  NSAssert(!_autocreator,
+//%           @"%@: Autocreator must be cleared before release, autocreator: %@",
+//%           [self class], _autocreator);
 //%  [_values[0] release];
 //%  [_values[1] release];
 //%  [super dealloc];
 //%}
-//%
-//%
 //%PDDM-DEFINE BOOL_DICT_W_HASOBJECT(IDX, REF)
 //%(BOOL_DICT_HASOBJECT(IDX, REF))
 //%PDDM-DEFINE BOOL_DICT_HASOBJECT(IDX, REF)
@@ -1363,6 +1416,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 //%        _values[i] = [otherDictionary->_values[i] retain];
 //%      }
 //%    }
+//%    if (_autocreator) {
+//%      GPBAutocreatedDictionaryModified(_autocreator, self);
+//%    }
 //%  }
 //%}
 //%
@@ -1370,6 +1426,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 //%  int idx = (key ? 1 : 0);
 //%  [_values[idx] release];
 //%  _values[idx] = [value retain];
+//%  if (_autocreator) {
+//%    GPBAutocreatedDictionaryModified(_autocreator, self);
+//%  }
 //%}
 //%
 //%- (void)removeValueForKey:(BOOL)aKey {
@@ -1466,6 +1525,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -1570,11 +1632,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBUInt32UInt32Dictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(uint32_t)value forKey:(uint32_t)key {
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(uint32_t)aKey {
@@ -1662,6 +1730,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -1766,11 +1837,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBUInt32Int32Dictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(int32_t)value forKey:(uint32_t)key {
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(uint32_t)aKey {
@@ -1858,6 +1935,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -1962,11 +2042,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBUInt32UInt64Dictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(uint64_t)value forKey:(uint32_t)key {
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(uint32_t)aKey {
@@ -2054,6 +2140,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -2158,11 +2247,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBUInt32Int64Dictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(int64_t)value forKey:(uint32_t)key {
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(uint32_t)aKey {
@@ -2250,6 +2345,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -2354,11 +2452,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBUInt32BoolDictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(BOOL)value forKey:(uint32_t)key {
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(uint32_t)aKey {
@@ -2446,6 +2550,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -2550,11 +2657,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBUInt32FloatDictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(float)value forKey:(uint32_t)key {
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(uint32_t)aKey {
@@ -2642,6 +2755,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -2746,11 +2862,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBUInt32DoubleDictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(double)value forKey:(uint32_t)key {
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(uint32_t)aKey {
@@ -2866,6 +2988,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -3008,11 +3133,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addRawEntriesFromDictionary:(GPBUInt32EnumDictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setRawValue:(int32_t)value forKey:(uint32_t)key {
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(uint32_t)aKey {
@@ -3031,6 +3162,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
   }
 
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 @end
@@ -3110,6 +3244,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -3234,11 +3371,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBUInt32ObjectDictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(id)value forKey:(uint32_t)key {
   [_dictionary setObject:value forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(uint32_t)aKey {
@@ -3329,6 +3472,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -3433,11 +3579,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBInt32UInt32Dictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(uint32_t)value forKey:(int32_t)key {
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(int32_t)aKey {
@@ -3525,6 +3677,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -3629,11 +3784,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBInt32Int32Dictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(int32_t)value forKey:(int32_t)key {
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(int32_t)aKey {
@@ -3721,6 +3882,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -3825,11 +3989,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBInt32UInt64Dictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(uint64_t)value forKey:(int32_t)key {
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(int32_t)aKey {
@@ -3917,6 +4087,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -4021,11 +4194,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBInt32Int64Dictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(int64_t)value forKey:(int32_t)key {
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(int32_t)aKey {
@@ -4113,6 +4292,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -4217,11 +4399,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBInt32BoolDictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(BOOL)value forKey:(int32_t)key {
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(int32_t)aKey {
@@ -4309,6 +4497,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -4413,11 +4604,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBInt32FloatDictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(float)value forKey:(int32_t)key {
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(int32_t)aKey {
@@ -4505,6 +4702,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -4609,11 +4809,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBInt32DoubleDictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(double)value forKey:(int32_t)key {
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(int32_t)aKey {
@@ -4729,6 +4935,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -4871,11 +5080,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addRawEntriesFromDictionary:(GPBInt32EnumDictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setRawValue:(int32_t)value forKey:(int32_t)key {
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(int32_t)aKey {
@@ -4894,6 +5109,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
   }
 
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 @end
@@ -4973,6 +5191,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -5097,11 +5318,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBInt32ObjectDictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(id)value forKey:(int32_t)key {
   [_dictionary setObject:value forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(int32_t)aKey {
@@ -5192,6 +5419,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -5296,11 +5526,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBUInt64UInt32Dictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(uint32_t)value forKey:(uint64_t)key {
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(uint64_t)aKey {
@@ -5388,6 +5624,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -5492,11 +5731,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBUInt64Int32Dictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(int32_t)value forKey:(uint64_t)key {
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(uint64_t)aKey {
@@ -5584,6 +5829,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -5688,11 +5936,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBUInt64UInt64Dictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(uint64_t)value forKey:(uint64_t)key {
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(uint64_t)aKey {
@@ -5780,6 +6034,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -5884,11 +6141,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBUInt64Int64Dictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(int64_t)value forKey:(uint64_t)key {
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(uint64_t)aKey {
@@ -5976,6 +6239,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -6080,11 +6346,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBUInt64BoolDictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(BOOL)value forKey:(uint64_t)key {
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(uint64_t)aKey {
@@ -6172,6 +6444,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -6276,11 +6551,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBUInt64FloatDictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(float)value forKey:(uint64_t)key {
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(uint64_t)aKey {
@@ -6368,6 +6649,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -6472,11 +6756,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBUInt64DoubleDictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(double)value forKey:(uint64_t)key {
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(uint64_t)aKey {
@@ -6592,6 +6882,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -6734,11 +7027,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addRawEntriesFromDictionary:(GPBUInt64EnumDictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setRawValue:(int32_t)value forKey:(uint64_t)key {
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(uint64_t)aKey {
@@ -6757,6 +7056,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
   }
 
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 @end
@@ -6836,6 +7138,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -6960,11 +7265,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBUInt64ObjectDictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(id)value forKey:(uint64_t)key {
   [_dictionary setObject:value forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(uint64_t)aKey {
@@ -7055,6 +7366,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -7159,11 +7473,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBInt64UInt32Dictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(uint32_t)value forKey:(int64_t)key {
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(int64_t)aKey {
@@ -7251,6 +7571,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -7355,11 +7678,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBInt64Int32Dictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(int32_t)value forKey:(int64_t)key {
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(int64_t)aKey {
@@ -7447,6 +7776,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -7551,11 +7883,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBInt64UInt64Dictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(uint64_t)value forKey:(int64_t)key {
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(int64_t)aKey {
@@ -7643,6 +7981,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -7747,11 +8088,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBInt64Int64Dictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(int64_t)value forKey:(int64_t)key {
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(int64_t)aKey {
@@ -7839,6 +8186,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -7943,11 +8293,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBInt64BoolDictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(BOOL)value forKey:(int64_t)key {
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(int64_t)aKey {
@@ -8035,6 +8391,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -8139,11 +8498,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBInt64FloatDictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(float)value forKey:(int64_t)key {
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(int64_t)aKey {
@@ -8231,6 +8596,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -8335,11 +8703,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBInt64DoubleDictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(double)value forKey:(int64_t)key {
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(int64_t)aKey {
@@ -8455,6 +8829,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -8597,11 +8974,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addRawEntriesFromDictionary:(GPBInt64EnumDictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setRawValue:(int32_t)value forKey:(int64_t)key {
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(int64_t)aKey {
@@ -8620,6 +9003,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
   }
 
   [_dictionary setObject:@(value) forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 @end
@@ -8699,6 +9085,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -8823,11 +9212,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBInt64ObjectDictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(id)value forKey:(int64_t)key {
   [_dictionary setObject:value forKey:@(key)];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(int64_t)aKey {
@@ -8918,6 +9313,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -9022,11 +9420,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBStringUInt32Dictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(uint32_t)value forKey:(NSString *)key {
   [_dictionary setObject:@(value) forKey:key];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(NSString *)aKey {
@@ -9114,6 +9518,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -9218,11 +9625,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBStringInt32Dictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(int32_t)value forKey:(NSString *)key {
   [_dictionary setObject:@(value) forKey:key];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(NSString *)aKey {
@@ -9310,6 +9723,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -9414,11 +9830,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBStringUInt64Dictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(uint64_t)value forKey:(NSString *)key {
   [_dictionary setObject:@(value) forKey:key];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(NSString *)aKey {
@@ -9506,6 +9928,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -9610,11 +10035,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBStringInt64Dictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(int64_t)value forKey:(NSString *)key {
   [_dictionary setObject:@(value) forKey:key];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(NSString *)aKey {
@@ -9702,6 +10133,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -9806,11 +10240,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBStringBoolDictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(BOOL)value forKey:(NSString *)key {
   [_dictionary setObject:@(value) forKey:key];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(NSString *)aKey {
@@ -9898,6 +10338,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -10002,11 +10445,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBStringFloatDictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(float)value forKey:(NSString *)key {
   [_dictionary setObject:@(value) forKey:key];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(NSString *)aKey {
@@ -10094,6 +10543,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -10198,11 +10650,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addEntriesFromDictionary:(GPBStringDoubleDictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setValue:(double)value forKey:(NSString *)key {
   [_dictionary setObject:@(value) forKey:key];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(NSString *)aKey {
@@ -10318,6 +10776,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_dictionary release];
   [super dealloc];
 }
@@ -10460,11 +10921,17 @@ void GPBDictionaryReadEntry(id mapDictionary,
 - (void)addRawEntriesFromDictionary:(GPBStringEnumDictionary *)otherDictionary {
   if (otherDictionary) {
     [_dictionary addEntriesFromDictionary:otherDictionary->_dictionary];
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
 - (void)setRawValue:(int32_t)value forKey:(NSString *)key {
   [_dictionary setObject:@(value) forKey:key];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(NSString *)aKey {
@@ -10483,6 +10950,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
   }
 
   [_dictionary setObject:@(value) forKey:key];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 @end
@@ -10572,6 +11042,15 @@ void GPBDictionaryReadEntry(id mapDictionary,
   return [self initWithValues:NULL forKeys:NULL count:0];
 }
 
+#if !defined(NS_BLOCK_ASSERTIONS)
+- (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
+  [super dealloc];
+}
+#endif  // !defined(NS_BLOCK_ASSERTIONS)
+
 - (instancetype)copyWithZone:(NSZone *)zone {
   return [[GPBBoolUInt32Dictionary allocWithZone:zone] initWithDictionary:self];
 }
@@ -10695,6 +11174,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
         _values[i] = otherDictionary->_values[i];
       }
     }
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
@@ -10702,6 +11184,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
   int idx = (key ? 1 : 0);
   _values[idx] = value;
   _valueSet[idx] = YES;
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(BOOL)aKey {
@@ -10797,6 +11282,15 @@ void GPBDictionaryReadEntry(id mapDictionary,
   return [self initWithValues:NULL forKeys:NULL count:0];
 }
 
+#if !defined(NS_BLOCK_ASSERTIONS)
+- (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
+  [super dealloc];
+}
+#endif  // !defined(NS_BLOCK_ASSERTIONS)
+
 - (instancetype)copyWithZone:(NSZone *)zone {
   return [[GPBBoolInt32Dictionary allocWithZone:zone] initWithDictionary:self];
 }
@@ -10920,6 +11414,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
         _values[i] = otherDictionary->_values[i];
       }
     }
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
@@ -10927,6 +11424,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
   int idx = (key ? 1 : 0);
   _values[idx] = value;
   _valueSet[idx] = YES;
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(BOOL)aKey {
@@ -11022,6 +11522,15 @@ void GPBDictionaryReadEntry(id mapDictionary,
   return [self initWithValues:NULL forKeys:NULL count:0];
 }
 
+#if !defined(NS_BLOCK_ASSERTIONS)
+- (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
+  [super dealloc];
+}
+#endif  // !defined(NS_BLOCK_ASSERTIONS)
+
 - (instancetype)copyWithZone:(NSZone *)zone {
   return [[GPBBoolUInt64Dictionary allocWithZone:zone] initWithDictionary:self];
 }
@@ -11145,6 +11654,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
         _values[i] = otherDictionary->_values[i];
       }
     }
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
@@ -11152,6 +11664,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
   int idx = (key ? 1 : 0);
   _values[idx] = value;
   _valueSet[idx] = YES;
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(BOOL)aKey {
@@ -11247,6 +11762,15 @@ void GPBDictionaryReadEntry(id mapDictionary,
   return [self initWithValues:NULL forKeys:NULL count:0];
 }
 
+#if !defined(NS_BLOCK_ASSERTIONS)
+- (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
+  [super dealloc];
+}
+#endif  // !defined(NS_BLOCK_ASSERTIONS)
+
 - (instancetype)copyWithZone:(NSZone *)zone {
   return [[GPBBoolInt64Dictionary allocWithZone:zone] initWithDictionary:self];
 }
@@ -11370,6 +11894,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
         _values[i] = otherDictionary->_values[i];
       }
     }
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
@@ -11377,6 +11904,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
   int idx = (key ? 1 : 0);
   _values[idx] = value;
   _valueSet[idx] = YES;
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(BOOL)aKey {
@@ -11472,6 +12002,15 @@ void GPBDictionaryReadEntry(id mapDictionary,
   return [self initWithValues:NULL forKeys:NULL count:0];
 }
 
+#if !defined(NS_BLOCK_ASSERTIONS)
+- (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
+  [super dealloc];
+}
+#endif  // !defined(NS_BLOCK_ASSERTIONS)
+
 - (instancetype)copyWithZone:(NSZone *)zone {
   return [[GPBBoolBoolDictionary allocWithZone:zone] initWithDictionary:self];
 }
@@ -11595,6 +12134,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
         _values[i] = otherDictionary->_values[i];
       }
     }
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
@@ -11602,6 +12144,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
   int idx = (key ? 1 : 0);
   _values[idx] = value;
   _valueSet[idx] = YES;
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(BOOL)aKey {
@@ -11697,6 +12242,15 @@ void GPBDictionaryReadEntry(id mapDictionary,
   return [self initWithValues:NULL forKeys:NULL count:0];
 }
 
+#if !defined(NS_BLOCK_ASSERTIONS)
+- (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
+  [super dealloc];
+}
+#endif  // !defined(NS_BLOCK_ASSERTIONS)
+
 - (instancetype)copyWithZone:(NSZone *)zone {
   return [[GPBBoolFloatDictionary allocWithZone:zone] initWithDictionary:self];
 }
@@ -11820,6 +12374,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
         _values[i] = otherDictionary->_values[i];
       }
     }
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
@@ -11827,6 +12384,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
   int idx = (key ? 1 : 0);
   _values[idx] = value;
   _valueSet[idx] = YES;
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(BOOL)aKey {
@@ -11922,6 +12482,15 @@ void GPBDictionaryReadEntry(id mapDictionary,
   return [self initWithValues:NULL forKeys:NULL count:0];
 }
 
+#if !defined(NS_BLOCK_ASSERTIONS)
+- (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
+  [super dealloc];
+}
+#endif  // !defined(NS_BLOCK_ASSERTIONS)
+
 - (instancetype)copyWithZone:(NSZone *)zone {
   return [[GPBBoolDoubleDictionary allocWithZone:zone] initWithDictionary:self];
 }
@@ -12045,6 +12614,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
         _values[i] = otherDictionary->_values[i];
       }
     }
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
@@ -12052,6 +12624,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
   int idx = (key ? 1 : 0);
   _values[idx] = value;
   _valueSet[idx] = YES;
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(BOOL)aKey {
@@ -12143,6 +12718,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 - (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
   [_values[0] release];
   [_values[1] release];
   [super dealloc];
@@ -12285,6 +12863,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
         _values[i] = [otherDictionary->_values[i] retain];
       }
     }
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
@@ -12292,6 +12873,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
   int idx = (key ? 1 : 0);
   [_values[idx] release];
   _values[idx] = [value retain];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(BOOL)aKey {
@@ -12418,6 +13002,15 @@ void GPBDictionaryReadEntry(id mapDictionary,
   return [self initWithValidationFunction:func rawValues:NULL forKeys:NULL count:0];
 }
 
+#if !defined(NS_BLOCK_ASSERTIONS)
+- (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
+  [super dealloc];
+}
+#endif  // !defined(NS_BLOCK_ASSERTIONS)
+
 - (instancetype)copyWithZone:(NSZone *)zone {
   return [[GPBBoolEnumDictionary allocWithZone:zone] initWithDictionary:self];
 }
@@ -12595,6 +13188,9 @@ void GPBDictionaryReadEntry(id mapDictionary,
         _values[i] = otherDictionary->_values[i];
       }
     }
+    if (_autocreator) {
+      GPBAutocreatedDictionaryModified(_autocreator, self);
+    }
   }
 }
 
@@ -12607,12 +13203,18 @@ void GPBDictionaryReadEntry(id mapDictionary,
   int idx = (key ? 1 : 0);
   _values[idx] = value;
   _valueSet[idx] = YES;
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)setRawValue:(int32_t)rawValue forKey:(BOOL)key {
   int idx = (key ? 1 : 0);
   _values[idx] = rawValue;
   _valueSet[idx] = YES;
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
 }
 
 - (void)removeValueForKey:(BOOL)aKey {
@@ -12625,3 +13227,110 @@ void GPBDictionaryReadEntry(id mapDictionary,
 }
 
 @end
+
+#pragma mark - NSDictionary Subclass
+
+@implementation GPBAutocreatedDictionary {
+  NSMutableDictionary *_dictionary;
+}
+
+- (void)dealloc {
+  NSAssert(!_autocreator,
+           @"%@: Autocreator must be cleared before release, autocreator: %@",
+           [self class], _autocreator);
+  [_dictionary release];
+  [super dealloc];
+}
+
+#pragma mark Required NSDictionary overrides
+
+- (instancetype)initWithObjects:(const id [])objects
+                        forKeys:(const id<NSCopying> [])keys
+                          count:(NSUInteger)count {
+  self = [super init];
+  if (self) {
+    _dictionary = [[NSMutableDictionary alloc] initWithObjects:objects
+                                                       forKeys:keys
+                                                         count:count];
+  }
+  return self;
+}
+
+- (NSUInteger)count {
+  return [_dictionary count];
+}
+
+- (id)objectForKey:(id)aKey {
+  return [_dictionary objectForKey:aKey];
+}
+
+- (NSEnumerator *)keyEnumerator {
+  if (_dictionary == nil) {
+    _dictionary = [[NSMutableDictionary alloc] init];
+  }
+  return [_dictionary keyEnumerator];
+}
+
+#pragma mark Required NSMutableDictionary overrides
+
+// Only need to call GPBAutocreatedDictionaryModified() when adding things
+// since we only autocreate empty dictionaries.
+
+- (void)setObject:(id)anObject forKey:(id<NSCopying>)aKey {
+  if (_dictionary == nil) {
+    _dictionary = [[NSMutableDictionary alloc] init];
+  }
+  [_dictionary setObject:anObject forKey:aKey];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
+}
+
+- (void)removeObjectForKey:(id)aKey {
+  [_dictionary removeObjectForKey:aKey];
+}
+
+#pragma mark Extra things hooked
+
+- (id)copyWithZone:(NSZone *)zone {
+  if (_dictionary == nil) {
+    _dictionary = [[NSMutableDictionary alloc] init];
+  }
+  return [_dictionary copyWithZone:zone];
+}
+
+- (id)mutableCopyWithZone:(NSZone *)zone {
+  if (_dictionary == nil) {
+    _dictionary = [[NSMutableDictionary alloc] init];
+  }
+  return [_dictionary mutableCopyWithZone:zone];
+}
+
+- (id)objectForKeyedSubscript:(id)key {
+  return [_dictionary objectForKeyedSubscript:key];
+}
+
+- (void)setObject:(id)obj forKeyedSubscript:(id<NSCopying>)key {
+  if (_dictionary == nil) {
+    _dictionary = [[NSMutableDictionary alloc] init];
+  }
+  [_dictionary setObject:obj forKeyedSubscript:key];
+  if (_autocreator) {
+    GPBAutocreatedDictionaryModified(_autocreator, self);
+  }
+}
+
+- (void)enumerateKeysAndObjectsUsingBlock:(void (^)(id key,
+                                                    id obj,
+                                                    BOOL *stop))block {
+  [_dictionary enumerateKeysAndObjectsUsingBlock:block];
+}
+
+- (void)enumerateKeysAndObjectsWithOptions:(NSEnumerationOptions)opts
+                                usingBlock:(void (^)(id key,
+                                                     id obj,
+                                                     BOOL *stop))block {
+  [_dictionary enumerateKeysAndObjectsWithOptions:opts usingBlock:block];
+}
+
+@end
diff --git a/objectivec/GPBDictionary_PackagePrivate.h b/objectivec/GPBDictionary_PackagePrivate.h
index 54b37dd8..9c3c5915 100644
--- a/objectivec/GPBDictionary_PackagePrivate.h
+++ b/objectivec/GPBDictionary_PackagePrivate.h
@@ -37,6 +37,14 @@
 @class GPBExtensionRegistry;
 @class GPBFieldDescriptor;
 
+@protocol GPBDictionaryInternalsProtocol
+- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
+- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
+                         asField:(GPBFieldDescriptor *)field;
+- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
+- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@end
+
 //%PDDM-DEFINE DICTIONARY_PRIV_INTERFACES_FOR_POD_KEY(KEY_NAME)
 //%DICTIONARY_POD_PRIV_INTERFACES_FOR_KEY(KEY_NAME)
 //%DICTIONARY_PRIVATE_INTERFACES(KEY_NAME, Object, Object)
@@ -51,12 +59,10 @@
 //%DICTIONARY_PRIVATE_INTERFACES(KEY_NAME, Enum, Enum)
 
 //%PDDM-DEFINE DICTIONARY_PRIVATE_INTERFACES(KEY_NAME, VALUE_NAME, HELPER)
-//%@interface GPB##KEY_NAME##VALUE_NAME##Dictionary ()
-//%- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-//%- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-//%                         asField:(GPBFieldDescriptor *)field;
-//%- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-//%- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+//%@interface GPB##KEY_NAME##VALUE_NAME##Dictionary () <GPBDictionaryInternalsProtocol> {
+//% @package
+//%  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+//%}
 //%EXTRA_DICTIONARY_PRIVATE_INTERFACES_##HELPER()@end
 //%
 
@@ -76,79 +82,61 @@
 //%PDDM-EXPAND DICTIONARY_PRIV_INTERFACES_FOR_POD_KEY(UInt32)
 // This block of code is generated, do not edit it directly.
 
-@interface GPBUInt32UInt32Dictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBUInt32UInt32Dictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBUInt32Int32Dictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBUInt32Int32Dictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBUInt32UInt64Dictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBUInt32UInt64Dictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBUInt32Int64Dictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBUInt32Int64Dictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBUInt32BoolDictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBUInt32BoolDictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBUInt32FloatDictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBUInt32FloatDictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBUInt32DoubleDictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBUInt32DoubleDictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBUInt32EnumDictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBUInt32EnumDictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 - (NSData *)serializedDataForUnknownValue:(int32_t)value
                                    forKey:(GPBValue *)key
                                   keyType:(GPBType)keyType;
 @end
 
-@interface GPBUInt32ObjectDictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBUInt32ObjectDictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 - (BOOL)isInitialized;
 - (instancetype)deepCopyWithZone:(NSZone *)zone
     __attribute__((ns_returns_retained));
@@ -157,79 +145,61 @@
 //%PDDM-EXPAND DICTIONARY_PRIV_INTERFACES_FOR_POD_KEY(Int32)
 // This block of code is generated, do not edit it directly.
 
-@interface GPBInt32UInt32Dictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBInt32UInt32Dictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBInt32Int32Dictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBInt32Int32Dictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBInt32UInt64Dictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBInt32UInt64Dictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBInt32Int64Dictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBInt32Int64Dictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBInt32BoolDictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBInt32BoolDictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBInt32FloatDictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBInt32FloatDictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBInt32DoubleDictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBInt32DoubleDictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBInt32EnumDictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBInt32EnumDictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 - (NSData *)serializedDataForUnknownValue:(int32_t)value
                                    forKey:(GPBValue *)key
                                   keyType:(GPBType)keyType;
 @end
 
-@interface GPBInt32ObjectDictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBInt32ObjectDictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 - (BOOL)isInitialized;
 - (instancetype)deepCopyWithZone:(NSZone *)zone
     __attribute__((ns_returns_retained));
@@ -238,79 +208,61 @@
 //%PDDM-EXPAND DICTIONARY_PRIV_INTERFACES_FOR_POD_KEY(UInt64)
 // This block of code is generated, do not edit it directly.
 
-@interface GPBUInt64UInt32Dictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBUInt64UInt32Dictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBUInt64Int32Dictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBUInt64Int32Dictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBUInt64UInt64Dictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBUInt64UInt64Dictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBUInt64Int64Dictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBUInt64Int64Dictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBUInt64BoolDictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBUInt64BoolDictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBUInt64FloatDictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBUInt64FloatDictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBUInt64DoubleDictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBUInt64DoubleDictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBUInt64EnumDictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBUInt64EnumDictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 - (NSData *)serializedDataForUnknownValue:(int32_t)value
                                    forKey:(GPBValue *)key
                                   keyType:(GPBType)keyType;
 @end
 
-@interface GPBUInt64ObjectDictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBUInt64ObjectDictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 - (BOOL)isInitialized;
 - (instancetype)deepCopyWithZone:(NSZone *)zone
     __attribute__((ns_returns_retained));
@@ -319,79 +271,61 @@
 //%PDDM-EXPAND DICTIONARY_PRIV_INTERFACES_FOR_POD_KEY(Int64)
 // This block of code is generated, do not edit it directly.
 
-@interface GPBInt64UInt32Dictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBInt64UInt32Dictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBInt64Int32Dictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBInt64Int32Dictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBInt64UInt64Dictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBInt64UInt64Dictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBInt64Int64Dictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBInt64Int64Dictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBInt64BoolDictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBInt64BoolDictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBInt64FloatDictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBInt64FloatDictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBInt64DoubleDictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBInt64DoubleDictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBInt64EnumDictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBInt64EnumDictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 - (NSData *)serializedDataForUnknownValue:(int32_t)value
                                    forKey:(GPBValue *)key
                                   keyType:(GPBType)keyType;
 @end
 
-@interface GPBInt64ObjectDictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBInt64ObjectDictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 - (BOOL)isInitialized;
 - (instancetype)deepCopyWithZone:(NSZone *)zone
     __attribute__((ns_returns_retained));
@@ -400,79 +334,61 @@
 //%PDDM-EXPAND DICTIONARY_PRIV_INTERFACES_FOR_POD_KEY(Bool)
 // This block of code is generated, do not edit it directly.
 
-@interface GPBBoolUInt32Dictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBBoolUInt32Dictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBBoolInt32Dictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBBoolInt32Dictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBBoolUInt64Dictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBBoolUInt64Dictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBBoolInt64Dictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBBoolInt64Dictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBBoolBoolDictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBBoolBoolDictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBBoolFloatDictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBBoolFloatDictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBBoolDoubleDictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBBoolDoubleDictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBBoolEnumDictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBBoolEnumDictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 - (NSData *)serializedDataForUnknownValue:(int32_t)value
                                    forKey:(GPBValue *)key
                                   keyType:(GPBType)keyType;
 @end
 
-@interface GPBBoolObjectDictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBBoolObjectDictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 - (BOOL)isInitialized;
 - (instancetype)deepCopyWithZone:(NSZone *)zone
     __attribute__((ns_returns_retained));
@@ -481,68 +397,52 @@
 //%PDDM-EXPAND DICTIONARY_POD_PRIV_INTERFACES_FOR_KEY(String)
 // This block of code is generated, do not edit it directly.
 
-@interface GPBStringUInt32Dictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBStringUInt32Dictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBStringInt32Dictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBStringInt32Dictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBStringUInt64Dictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBStringUInt64Dictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBStringInt64Dictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBStringInt64Dictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBStringBoolDictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBStringBoolDictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBStringFloatDictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBStringFloatDictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBStringDoubleDictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBStringDoubleDictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 @end
 
-@interface GPBStringEnumDictionary ()
-- (size_t)computeSerializedSizeAsField:(GPBFieldDescriptor *)field;
-- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)outputStream
-                         asField:(GPBFieldDescriptor *)field;
-- (void)setGPBValue:(GPBValue *)value forGPBValueKey:(GPBValue *)key;
-- (void)enumerateForTextFormat:(void (^)(id keyObj, id valueObj))block;
+@interface GPBStringEnumDictionary () <GPBDictionaryInternalsProtocol> {
+ @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
 - (NSData *)serializedDataForUnknownValue:(int32_t)value
                                    forKey:(GPBValue *)key
                                   keyType:(GPBType)keyType;
@@ -550,6 +450,16 @@
 
 //%PDDM-EXPAND-END (6 expansions)
 
+#pragma mark - NSDictionary Subclass
+
+@interface GPBAutocreatedDictionary : NSMutableDictionary {
+  @package
+  GPB_UNSAFE_UNRETAINED GPBMessage *_autocreator;
+}
+@end
+
+#pragma mark - Helpers
+
 CF_EXTERN_C_BEGIN
 
 // Helper to compute size when an NSDictionary is used for the map instead
diff --git a/objectivec/GPBExtensionRegistry.h b/objectivec/GPBExtensionRegistry.h
index ce1f8fab..e382971c 100644
--- a/objectivec/GPBExtensionRegistry.h
+++ b/objectivec/GPBExtensionRegistry.h
@@ -38,7 +38,24 @@
 // ExtensionRegistry in which you have registered any extensions that you want
 // to be able to parse.  Otherwise, those extensions will just be treated like
 // unknown fields.
-@interface GPBExtensionRegistry : NSObject
+//
+// The *Root classes provide +extensionRegistry for the extensions defined in a
+// given file *and* all files it imports.  You can also create a
+// GPBExtensionRegistry, and merge those registries to handle parsing extensions
+// defined from non overlapping files.
+//
+//    GPBExtensionRegistry *registry =
+//        [[[MyProtoFileRoot extensionRegistry] copy] autorelease];
+//    [registry addExtension:[OtherMessage neededExtension];  // Not in MyProtoFile
+//    NSError *parseError = nil;
+//    MyMessage *msg = [MyMessage parseData:data
+//                        extensionRegistry:registry
+//                                    error:&parseError];
+//
+@interface GPBExtensionRegistry : NSObject<NSCopying>
+
+- (void)addExtension:(GPBExtensionField *)extension;
+- (void)addExtensions:(GPBExtensionRegistry *)registry;
 
 - (GPBExtensionField *)getExtension:(GPBDescriptor *)containingType
                         fieldNumber:(NSInteger)fieldNumber;
diff --git a/objectivec/GPBExtensionRegistry.m b/objectivec/GPBExtensionRegistry.m
index a191dace..4f234f55 100644
--- a/objectivec/GPBExtensionRegistry.m
+++ b/objectivec/GPBExtensionRegistry.m
@@ -28,7 +28,7 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-#import "GPBExtensionRegistry_PackagePrivate.h"
+#import "GPBExtensionRegistry.h"
 
 #import "GPBBootstrap.h"
 #import "GPBDescriptor.h"
@@ -52,6 +52,14 @@
   [super dealloc];
 }
 
+- (instancetype)copyWithZone:(NSZone *)zone {
+  GPBExtensionRegistry *result = [[[self class] allocWithZone:zone] init];
+  if (result && mutableClassMap_.count) {
+    [result->mutableClassMap_ addEntriesFromDictionary:mutableClassMap_];
+  }
+  return result;
+}
+
 - (NSMutableDictionary *)extensionMapForContainingType:
         (GPBDescriptor *)containingType {
   NSMutableDictionary *extensionMap =
diff --git a/objectivec/GPBExtensionRegistry_PackagePrivate.h b/objectivec/GPBExtensionRegistry_PackagePrivate.h
deleted file mode 100644
index 968cb1fd..00000000
--- a/objectivec/GPBExtensionRegistry_PackagePrivate.h
+++ /dev/null
@@ -1,40 +0,0 @@
-// Protocol Buffers - Google's data interchange format
-// Copyright 2008 Google Inc.  All rights reserved.
-// https://developers.google.com/protocol-buffers/
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-#import <Foundation/Foundation.h>
-
-#import "GPBExtensionRegistry.h"
-
-@interface GPBExtensionRegistry ()
-
-- (void)addExtension:(GPBExtensionField *)extension;
-- (void)addExtensions:(GPBExtensionRegistry *)registry;
-
-@end
diff --git a/objectivec/GPBMessage.h b/objectivec/GPBMessage.h
index 2483f5d3..1c6c091d 100644
--- a/objectivec/GPBMessage.h
+++ b/objectivec/GPBMessage.h
@@ -28,15 +28,28 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-#import "GPBRootObject.h"
+#import <Foundation/Foundation.h>
+
+#import "GPBBootstrap.h"
 
 @class GPBDescriptor;
 @class GPBCodedInputStream;
 @class GPBCodedOutputStream;
 @class GPBExtensionField;
+@class GPBExtensionRegistry;
 @class GPBFieldDescriptor;
 @class GPBUnknownFieldSet;
 
+CF_EXTERN_C_BEGIN
+
+// NSError domain used for errors.
+extern NSString *const GPBMessageErrorDomain;
+
+typedef NS_ENUM(NSInteger, GPBMessageErrorCode) {
+  GPBMessageErrorCodeMalformedData = -100,
+  GPBMessageErrorCodeMissingRequiredField = -101,
+};
+
 // In DEBUG ONLY, an NSException is thrown when a parsed message doesn't
 // contain required fields. This key allows you to retrieve the parsed message
 // from the exception's |userInfo| dictionary.
@@ -44,12 +57,14 @@
 extern NSString *const GPBExceptionMessageKey;
 #endif  // DEBUG
 
-// NOTE:
-// If you add a instance method/property to this class that may conflict with
-// methods declared in protos, you need to update objective_helpers.cc.
+CF_EXTERN_C_END
+
+@interface GPBMessage : NSObject<NSSecureCoding, NSCopying>
+
+// NOTE: If you add a instance method/property to this class that may conflict
+// with methods declared in protos, you need to update objective_helpers.cc.
 // The main cases are methods that take no arguments, or setFoo:/hasFoo: type
 // methods.
-@interface GPBMessage : GPBRootObject<NSCoding, NSCopying>
 
 @property(nonatomic, readonly) GPBUnknownFieldSet *unknownFields;
 
@@ -59,29 +74,38 @@ extern NSString *const GPBExceptionMessageKey;
 // Returns an autoreleased instance.
 + (instancetype)message;
 
-// Create a message based on a variety of inputs.
-// In DEBUG ONLY
-// @throws NSInternalInconsistencyException The message is missing one or more
-//         required fields (i.e. -[isInitialized] returns false). Use
-//         GGPBExceptionMessageKey to retrieve the message from |userInfo|.
-+ (instancetype)parseFromData:(NSData *)data;
+// Create a message based on a variety of inputs.  If there is a data parse
+// error, nil is returned and if not NULL, errorPtr is filled in.
+// NOTE: In DEBUG ONLY, the message is also checked for all required field,
+// if one is missing, the parse will fail (returning nil, filling in errorPtr).
++ (instancetype)parseFromData:(NSData *)data error:(NSError **)errorPtr;
 + (instancetype)parseFromData:(NSData *)data
-            extensionRegistry:(GPBExtensionRegistry *)extensionRegistry;
+            extensionRegistry:(GPBExtensionRegistry *)extensionRegistry
+                        error:(NSError **)errorPtr;
 + (instancetype)parseFromCodedInputStream:(GPBCodedInputStream *)input
                         extensionRegistry:
-                            (GPBExtensionRegistry *)extensionRegistry;
+                            (GPBExtensionRegistry *)extensionRegistry
+                                    error:(NSError **)errorPtr;
 
-// Create a message based on delimited input.
+// Create a message based on delimited input.  If there is a data parse
+// error, nil is returned and if not NULL, errorPtr is filled in.
 + (instancetype)parseDelimitedFromCodedInputStream:(GPBCodedInputStream *)input
                                  extensionRegistry:
-                                     (GPBExtensionRegistry *)extensionRegistry;
-
-- (instancetype)initWithData:(NSData *)data;
+                                     (GPBExtensionRegistry *)extensionRegistry
+                                             error:(NSError **)errorPtr;
+
+// If there is a data parse error, nil is returned and if not NULL, errorPtr is
+// filled in.
+// NOTE: In DEBUG ONLY, the message is also checked for all required field,
+// if one is missing, the parse will fail (returning nil, filling in errorPtr).
+- (instancetype)initWithData:(NSData *)data error:(NSError **)errorPtr;
 - (instancetype)initWithData:(NSData *)data
-           extensionRegistry:(GPBExtensionRegistry *)extensionRegistry;
+           extensionRegistry:(GPBExtensionRegistry *)extensionRegistry
+                       error:(NSError **)errorPtr;
 - (instancetype)initWithCodedInputStream:(GPBCodedInputStream *)input
                        extensionRegistry:
-                           (GPBExtensionRegistry *)extensionRegistry;
+                           (GPBExtensionRegistry *)extensionRegistry
+                                   error:(NSError **)errorPtr;
 
 // Serializes the message and writes it to output.
 - (void)writeToCodedOutputStream:(GPBCodedOutputStream *)output;
@@ -93,11 +117,10 @@ extern NSString *const GPBExceptionMessageKey;
 - (void)writeDelimitedToOutputStream:(NSOutputStream *)output;
 
 // Serializes the message to an NSData. Note that this value is not cached, so
-// if you are using it repeatedly, cache it yourself.
-// In DEBUG ONLY:
-// @throws NSInternalInconsistencyException The message is missing one or more
-//         required fields (i.e. -[isInitialized] returns false). Use
-//         GPBExceptionMessageKey to retrieve the message from |userInfo|.
+// if you are using it repeatedly, cache it yourself. If there is an error
+// while generating the data, nil is returned.
+// NOTE: In DEBUG ONLY, the message is also checked for all required field,
+// if one is missing, nil will be returned.
 - (NSData *)data;
 
 // Same as -[data], except a delimiter is added to the start of the data
@@ -106,16 +129,16 @@ extern NSString *const GPBExceptionMessageKey;
 
 // Returns the size of the object if it were serialized.
 // This is not a cached value. If you are following a pattern like this:
-// size_t size = [aMsg serializedSize];
-// NSMutableData *foo = [NSMutableData dataWithCapacity:size + sizeof(size)];
-// [foo writeSize:size];
-// [foo appendData:[aMsg data]];
+//   size_t size = [aMsg serializedSize];
+//   NSMutableData *foo = [NSMutableData dataWithCapacity:size + sizeof(size)];
+//   [foo writeSize:size];
+//   [foo appendData:[aMsg data]];
 // you would be better doing:
-// NSData *data = [aMsg data];
-// NSUInteger size = [aMsg length];
-// NSMutableData *foo = [NSMutableData dataWithCapacity:size + sizeof(size)];
-// [foo writeSize:size];
-// [foo appendData:data];
+//   NSData *data = [aMsg data];
+//   NSUInteger size = [aMsg length];
+//   NSMutableData *foo = [NSMutableData dataWithCapacity:size + sizeof(size)];
+//   [foo writeSize:size];
+//   [foo appendData:data];
 - (size_t)serializedSize;
 
 // Return the descriptor for the message
@@ -123,8 +146,8 @@ extern NSString *const GPBExceptionMessageKey;
 - (GPBDescriptor *)descriptor;
 
 // Extensions use boxed values (NSNumbers) for PODs, NSMutableArrays for
-// repeated. If the extension is a Message, just like fields, one will be
-// auto created for you and returned.
+// repeated. If the extension is a Message one will be auto created for you
+// and returned similar to fields.
 - (BOOL)hasExtension:(GPBExtensionField *)extension;
 - (id)getExtension:(GPBExtensionField *)extension;
 - (void)setExtension:(GPBExtensionField *)extension value:(id)value;
@@ -141,6 +164,7 @@ extern NSString *const GPBExceptionMessageKey;
 
 // Parses a message of this type from the input and merges it with this
 // message.
+// NOTE: This will throw if there is an error parsing the data.
 - (void)mergeFromData:(NSData *)data
     extensionRegistry:(GPBExtensionRegistry *)extensionRegistry;
 
diff --git a/objectivec/GPBMessage.m b/objectivec/GPBMessage.m
index 63ffc3bc..bd3235f1 100644
--- a/objectivec/GPBMessage.m
+++ b/objectivec/GPBMessage.m
@@ -39,15 +39,21 @@
 #import "GPBDescriptor_PackagePrivate.h"
 #import "GPBDictionary_PackagePrivate.h"
 #import "GPBExtensionField_PackagePrivate.h"
-#import "GPBExtensionRegistry_PackagePrivate.h"
+#import "GPBExtensionRegistry.h"
+#import "GPBRootObject_PackagePrivate.h"
 #import "GPBUnknownFieldSet_PackagePrivate.h"
 #import "GPBUtilities_PackagePrivate.h"
 
+NSString *const GPBMessageErrorDomain =
+    GPBNSStringifySymbol(GPBMessageErrorDomain);
+
 #ifdef DEBUG
 NSString *const GPBExceptionMessageKey =
     GPBNSStringifySymbol(GPBExceptionMessage);
 #endif  // DEBUG
 
+static NSString *const kGPBDataCoderKey = @"GPBData";
+
 //
 // PLEASE REMEMBER:
 //
@@ -78,13 +84,32 @@ static id GetOrCreateArrayIvarWithField(GPBMessage *self,
                                         GPBFieldDescriptor *field,
                                         GPBFileSyntax syntax);
 static id GetArrayIvarWithField(GPBMessage *self, GPBFieldDescriptor *field);
+static id CreateMapForField(GPBFieldDescriptor *field,
+                            GPBMessage *autocreator)
+    __attribute__((ns_returns_retained));
 static id GetOrCreateMapIvarWithField(GPBMessage *self,
                                       GPBFieldDescriptor *field,
                                       GPBFileSyntax syntax);
+static id GetMapIvarWithField(GPBMessage *self, GPBFieldDescriptor *field);
 static NSMutableDictionary *CloneExtensionMap(NSDictionary *extensionMap,
                                               NSZone *zone)
     __attribute__((ns_returns_retained));
 
+static NSError *MessageError(NSInteger code, NSDictionary *userInfo) {
+  return [NSError errorWithDomain:GPBMessageErrorDomain
+                             code:code
+                         userInfo:userInfo];
+}
+
+static NSError *MessageErrorWithReason(NSInteger code, NSString *reason) {
+  NSDictionary *userInfo = nil;
+  if ([reason length]) {
+    userInfo = @{ @"Reason" : reason };
+  }
+  return MessageError(code, userInfo);
+}
+
+
 static void CheckExtension(GPBMessage *self, GPBExtensionField *extension) {
   if ([[self class] descriptor] != [extension containingType]) {
     [NSException
@@ -201,6 +226,303 @@ static id CreateArrayForField(GPBFieldDescriptor *field,
   return result;
 }
 
+static id CreateMapForField(GPBFieldDescriptor *field,
+                            GPBMessage *autocreator) {
+  id result;
+  GPBType keyType = field.mapKeyType;
+  GPBType valueType = GPBGetFieldType(field);
+  switch (keyType) {
+    case GPBTypeBool:
+      switch (valueType) {
+        case GPBTypeBool:
+          result = [[GPBBoolBoolDictionary alloc] init];
+          break;
+        case GPBTypeFixed32:
+        case GPBTypeUInt32:
+          result = [[GPBBoolUInt32Dictionary alloc] init];
+          break;
+        case GPBTypeInt32:
+        case GPBTypeSFixed32:
+        case GPBTypeSInt32:
+          result = [[GPBBoolInt32Dictionary alloc] init];
+          break;
+        case GPBTypeFixed64:
+        case GPBTypeUInt64:
+          result = [[GPBBoolUInt64Dictionary alloc] init];
+          break;
+        case GPBTypeInt64:
+        case GPBTypeSFixed64:
+        case GPBTypeSInt64:
+          result = [[GPBBoolInt64Dictionary alloc] init];
+          break;
+        case GPBTypeFloat:
+          result = [[GPBBoolFloatDictionary alloc] init];
+          break;
+        case GPBTypeDouble:
+          result = [[GPBBoolDoubleDictionary alloc] init];
+          break;
+        case GPBTypeEnum:
+          result = [[GPBBoolEnumDictionary alloc]
+              initWithValidationFunction:field.enumDescriptor.enumVerifier];
+          break;
+        case GPBTypeData:
+        case GPBTypeMessage:
+        case GPBTypeString:
+          result = [[GPBBoolObjectDictionary alloc] init];
+          break;
+        case GPBTypeGroup:
+          NSCAssert(NO, @"shouldn't happen");
+          return nil;
+      }
+      break;
+    case GPBTypeFixed32:
+    case GPBTypeUInt32:
+      switch (valueType) {
+        case GPBTypeBool:
+          result = [[GPBUInt32BoolDictionary alloc] init];
+          break;
+        case GPBTypeFixed32:
+        case GPBTypeUInt32:
+          result = [[GPBUInt32UInt32Dictionary alloc] init];
+          break;
+        case GPBTypeInt32:
+        case GPBTypeSFixed32:
+        case GPBTypeSInt32:
+          result = [[GPBUInt32Int32Dictionary alloc] init];
+          break;
+        case GPBTypeFixed64:
+        case GPBTypeUInt64:
+          result = [[GPBUInt32UInt64Dictionary alloc] init];
+          break;
+        case GPBTypeInt64:
+        case GPBTypeSFixed64:
+        case GPBTypeSInt64:
+          result = [[GPBUInt32Int64Dictionary alloc] init];
+          break;
+        case GPBTypeFloat:
+          result = [[GPBUInt32FloatDictionary alloc] init];
+          break;
+        case GPBTypeDouble:
+          result = [[GPBUInt32DoubleDictionary alloc] init];
+          break;
+        case GPBTypeEnum:
+          result = [[GPBUInt32EnumDictionary alloc]
+              initWithValidationFunction:field.enumDescriptor.enumVerifier];
+          break;
+        case GPBTypeData:
+        case GPBTypeMessage:
+        case GPBTypeString:
+          result = [[GPBUInt32ObjectDictionary alloc] init];
+          break;
+        case GPBTypeGroup:
+          NSCAssert(NO, @"shouldn't happen");
+          return nil;
+      }
+      break;
+    case GPBTypeInt32:
+    case GPBTypeSFixed32:
+    case GPBTypeSInt32:
+      switch (valueType) {
+        case GPBTypeBool:
+          result = [[GPBInt32BoolDictionary alloc] init];
+          break;
+        case GPBTypeFixed32:
+        case GPBTypeUInt32:
+          result = [[GPBInt32UInt32Dictionary alloc] init];
+          break;
+        case GPBTypeInt32:
+        case GPBTypeSFixed32:
+        case GPBTypeSInt32:
+          result = [[GPBInt32Int32Dictionary alloc] init];
+          break;
+        case GPBTypeFixed64:
+        case GPBTypeUInt64:
+          result = [[GPBInt32UInt64Dictionary alloc] init];
+          break;
+        case GPBTypeInt64:
+        case GPBTypeSFixed64:
+        case GPBTypeSInt64:
+          result = [[GPBInt32Int64Dictionary alloc] init];
+          break;
+        case GPBTypeFloat:
+          result = [[GPBInt32FloatDictionary alloc] init];
+          break;
+        case GPBTypeDouble:
+          result = [[GPBInt32DoubleDictionary alloc] init];
+          break;
+        case GPBTypeEnum:
+          result = [[GPBInt32EnumDictionary alloc]
+              initWithValidationFunction:field.enumDescriptor.enumVerifier];
+          break;
+        case GPBTypeData:
+        case GPBTypeMessage:
+        case GPBTypeString:
+          result = [[GPBInt32ObjectDictionary alloc] init];
+          break;
+        case GPBTypeGroup:
+          NSCAssert(NO, @"shouldn't happen");
+          return nil;
+      }
+      break;
+    case GPBTypeFixed64:
+    case GPBTypeUInt64:
+      switch (valueType) {
+        case GPBTypeBool:
+          result = [[GPBUInt64BoolDictionary alloc] init];
+          break;
+        case GPBTypeFixed32:
+        case GPBTypeUInt32:
+          result = [[GPBUInt64UInt32Dictionary alloc] init];
+          break;
+        case GPBTypeInt32:
+        case GPBTypeSFixed32:
+        case GPBTypeSInt32:
+          result = [[GPBUInt64Int32Dictionary alloc] init];
+          break;
+        case GPBTypeFixed64:
+        case GPBTypeUInt64:
+          result = [[GPBUInt64UInt64Dictionary alloc] init];
+          break;
+        case GPBTypeInt64:
+        case GPBTypeSFixed64:
+        case GPBTypeSInt64:
+          result = [[GPBUInt64Int64Dictionary alloc] init];
+          break;
+        case GPBTypeFloat:
+          result = [[GPBUInt64FloatDictionary alloc] init];
+          break;
+        case GPBTypeDouble:
+          result = [[GPBUInt64DoubleDictionary alloc] init];
+          break;
+        case GPBTypeEnum:
+          result = [[GPBUInt64EnumDictionary alloc]
+              initWithValidationFunction:field.enumDescriptor.enumVerifier];
+          break;
+        case GPBTypeData:
+        case GPBTypeMessage:
+        case GPBTypeString:
+          result = [[GPBUInt64ObjectDictionary alloc] init];
+          break;
+        case GPBTypeGroup:
+          NSCAssert(NO, @"shouldn't happen");
+          return nil;
+      }
+      break;
+    case GPBTypeInt64:
+    case GPBTypeSFixed64:
+    case GPBTypeSInt64:
+      switch (valueType) {
+        case GPBTypeBool:
+          result = [[GPBInt64BoolDictionary alloc] init];
+          break;
+        case GPBTypeFixed32:
+        case GPBTypeUInt32:
+          result = [[GPBInt64UInt32Dictionary alloc] init];
+          break;
+        case GPBTypeInt32:
+        case GPBTypeSFixed32:
+        case GPBTypeSInt32:
+          result = [[GPBInt64Int32Dictionary alloc] init];
+          break;
+        case GPBTypeFixed64:
+        case GPBTypeUInt64:
+          result = [[GPBInt64UInt64Dictionary alloc] init];
+          break;
+        case GPBTypeInt64:
+        case GPBTypeSFixed64:
+        case GPBTypeSInt64:
+          result = [[GPBInt64Int64Dictionary alloc] init];
+          break;
+        case GPBTypeFloat:
+          result = [[GPBInt64FloatDictionary alloc] init];
+          break;
+        case GPBTypeDouble:
+          result = [[GPBInt64DoubleDictionary alloc] init];
+          break;
+        case GPBTypeEnum:
+          result = [[GPBInt64EnumDictionary alloc]
+              initWithValidationFunction:field.enumDescriptor.enumVerifier];
+          break;
+        case GPBTypeData:
+        case GPBTypeMessage:
+        case GPBTypeString:
+          result = [[GPBInt64ObjectDictionary alloc] init];
+          break;
+        case GPBTypeGroup:
+          NSCAssert(NO, @"shouldn't happen");
+          return nil;
+      }
+      break;
+    case GPBTypeString:
+      switch (valueType) {
+        case GPBTypeBool:
+          result = [[GPBStringBoolDictionary alloc] init];
+          break;
+        case GPBTypeFixed32:
+        case GPBTypeUInt32:
+          result = [[GPBStringUInt32Dictionary alloc] init];
+          break;
+        case GPBTypeInt32:
+        case GPBTypeSFixed32:
+        case GPBTypeSInt32:
+          result = [[GPBStringInt32Dictionary alloc] init];
+          break;
+        case GPBTypeFixed64:
+        case GPBTypeUInt64:
+          result = [[GPBStringUInt64Dictionary alloc] init];
+          break;
+        case GPBTypeInt64:
+        case GPBTypeSFixed64:
+        case GPBTypeSInt64:
+          result = [[GPBStringInt64Dictionary alloc] init];
+          break;
+        case GPBTypeFloat:
+          result = [[GPBStringFloatDictionary alloc] init];
+          break;
+        case GPBTypeDouble:
+          result = [[GPBStringDoubleDictionary alloc] init];
+          break;
+        case GPBTypeEnum:
+          result = [[GPBStringEnumDictionary alloc]
+              initWithValidationFunction:field.enumDescriptor.enumVerifier];
+          break;
+        case GPBTypeData:
+        case GPBTypeMessage:
+        case GPBTypeString:
+          if (autocreator) {
+            result = [[GPBAutocreatedDictionary alloc] init];
+          } else {
+            result = [[NSMutableDictionary alloc] init];
+          }
+          break;
+        case GPBTypeGroup:
+          NSCAssert(NO, @"shouldn't happen");
+          return nil;
+      }
+      break;
+
+    case GPBTypeFloat:
+    case GPBTypeDouble:
+    case GPBTypeEnum:
+    case GPBTypeData:
+    case GPBTypeGroup:
+    case GPBTypeMessage:
+      NSCAssert(NO, @"shouldn't happen");
+      return nil;
+  }
+
+  if (autocreator) {
+    if ((keyType == GPBTypeString) && GPBTypeIsObject(valueType)) {
+      GPBAutocreatedDictionary *autoDict = result;
+      autoDict->_autocreator =  autocreator;
+    } else {
+      GPBInt32Int32Dictionary *gpbDict = result;
+      gpbDict->_autocreator = autocreator;
+    }
+  }
+
+  return result;
+}
 
 #if !defined(__clang_analyzer__)
 // These functions are blocked from the analyzer because the analyzer sees the
@@ -249,285 +571,27 @@ static id GetOrCreateMapIvarWithField(GPBMessage *self,
                                       GPBFileSyntax syntax) {
   id dict = GPBGetObjectIvarWithFieldNoAutocreate(self, field);
   if (!dict) {
-    GPBType keyType = field.mapKeyType;
-    GPBType valueType = GPBGetFieldType(field);
-    switch (keyType) {
-      case GPBTypeBool:
-        switch (valueType) {
-          case GPBTypeBool:
-            dict = [[GPBBoolBoolDictionary alloc] init];
-            break;
-          case GPBTypeFixed32:
-          case GPBTypeUInt32:
-            dict = [[GPBBoolUInt32Dictionary alloc] init];
-            break;
-          case GPBTypeInt32:
-          case GPBTypeSFixed32:
-          case GPBTypeSInt32:
-            dict = [[GPBBoolInt32Dictionary alloc] init];
-            break;
-          case GPBTypeFixed64:
-          case GPBTypeUInt64:
-            dict = [[GPBBoolUInt64Dictionary alloc] init];
-            break;
-          case GPBTypeInt64:
-          case GPBTypeSFixed64:
-          case GPBTypeSInt64:
-            dict = [[GPBBoolInt64Dictionary alloc] init];
-            break;
-          case GPBTypeFloat:
-            dict = [[GPBBoolFloatDictionary alloc] init];
-            break;
-          case GPBTypeDouble:
-            dict = [[GPBBoolDoubleDictionary alloc] init];
-            break;
-          case GPBTypeEnum:
-            dict = [[GPBBoolEnumDictionary alloc]
-                initWithValidationFunction:field.enumDescriptor.enumVerifier];
-            break;
-          case GPBTypeData:
-          case GPBTypeMessage:
-          case GPBTypeString:
-            dict = [[GPBBoolObjectDictionary alloc] init];
-            break;
-          case GPBTypeGroup:
-            NSCAssert(NO, @"shouldn't happen");
-            return nil;
-        }
-        break;
-      case GPBTypeFixed32:
-      case GPBTypeUInt32:
-        switch (valueType) {
-          case GPBTypeBool:
-            dict = [[GPBUInt32BoolDictionary alloc] init];
-            break;
-          case GPBTypeFixed32:
-          case GPBTypeUInt32:
-            dict = [[GPBUInt32UInt32Dictionary alloc] init];
-            break;
-          case GPBTypeInt32:
-          case GPBTypeSFixed32:
-          case GPBTypeSInt32:
-            dict = [[GPBUInt32Int32Dictionary alloc] init];
-            break;
-          case GPBTypeFixed64:
-          case GPBTypeUInt64:
-            dict = [[GPBUInt32UInt64Dictionary alloc] init];
-            break;
-          case GPBTypeInt64:
-          case GPBTypeSFixed64:
-          case GPBTypeSInt64:
-            dict = [[GPBUInt32Int64Dictionary alloc] init];
-            break;
-          case GPBTypeFloat:
-            dict = [[GPBUInt32FloatDictionary alloc] init];
-            break;
-          case GPBTypeDouble:
-            dict = [[GPBUInt32DoubleDictionary alloc] init];
-            break;
-          case GPBTypeEnum:
-            dict = [[GPBUInt32EnumDictionary alloc]
-                initWithValidationFunction:field.enumDescriptor.enumVerifier];
-            break;
-          case GPBTypeData:
-          case GPBTypeMessage:
-          case GPBTypeString:
-            dict = [[GPBUInt32ObjectDictionary alloc] init];
-            break;
-          case GPBTypeGroup:
-            NSCAssert(NO, @"shouldn't happen");
-            return nil;
-        }
-        break;
-      case GPBTypeInt32:
-      case GPBTypeSFixed32:
-      case GPBTypeSInt32:
-        switch (valueType) {
-          case GPBTypeBool:
-            dict = [[GPBInt32BoolDictionary alloc] init];
-            break;
-          case GPBTypeFixed32:
-          case GPBTypeUInt32:
-            dict = [[GPBInt32UInt32Dictionary alloc] init];
-            break;
-          case GPBTypeInt32:
-          case GPBTypeSFixed32:
-          case GPBTypeSInt32:
-            dict = [[GPBInt32Int32Dictionary alloc] init];
-            break;
-          case GPBTypeFixed64:
-          case GPBTypeUInt64:
-            dict = [[GPBInt32UInt64Dictionary alloc] init];
-            break;
-          case GPBTypeInt64:
-          case GPBTypeSFixed64:
-          case GPBTypeSInt64:
-            dict = [[GPBInt32Int64Dictionary alloc] init];
-            break;
-          case GPBTypeFloat:
-            dict = [[GPBInt32FloatDictionary alloc] init];
-            break;
-          case GPBTypeDouble:
-            dict = [[GPBInt32DoubleDictionary alloc] init];
-            break;
-          case GPBTypeEnum:
-            dict = [[GPBInt32EnumDictionary alloc]
-                initWithValidationFunction:field.enumDescriptor.enumVerifier];
-            break;
-          case GPBTypeData:
-          case GPBTypeMessage:
-          case GPBTypeString:
-            dict = [[GPBInt32ObjectDictionary alloc] init];
-            break;
-          case GPBTypeGroup:
-            NSCAssert(NO, @"shouldn't happen");
-            return nil;
-        }
-        break;
-      case GPBTypeFixed64:
-      case GPBTypeUInt64:
-        switch (valueType) {
-          case GPBTypeBool:
-            dict = [[GPBUInt64BoolDictionary alloc] init];
-            break;
-          case GPBTypeFixed32:
-          case GPBTypeUInt32:
-            dict = [[GPBUInt64UInt32Dictionary alloc] init];
-            break;
-          case GPBTypeInt32:
-          case GPBTypeSFixed32:
-          case GPBTypeSInt32:
-            dict = [[GPBUInt64Int32Dictionary alloc] init];
-            break;
-          case GPBTypeFixed64:
-          case GPBTypeUInt64:
-            dict = [[GPBUInt64UInt64Dictionary alloc] init];
-            break;
-          case GPBTypeInt64:
-          case GPBTypeSFixed64:
-          case GPBTypeSInt64:
-            dict = [[GPBUInt64Int64Dictionary alloc] init];
-            break;
-          case GPBTypeFloat:
-            dict = [[GPBUInt64FloatDictionary alloc] init];
-            break;
-          case GPBTypeDouble:
-            dict = [[GPBUInt64DoubleDictionary alloc] init];
-            break;
-          case GPBTypeEnum:
-            dict = [[GPBUInt64EnumDictionary alloc]
-                initWithValidationFunction:field.enumDescriptor.enumVerifier];
-            break;
-          case GPBTypeData:
-          case GPBTypeMessage:
-          case GPBTypeString:
-            dict = [[GPBUInt64ObjectDictionary alloc] init];
-            break;
-          case GPBTypeGroup:
-            NSCAssert(NO, @"shouldn't happen");
-            return nil;
-        }
-        break;
-      case GPBTypeInt64:
-      case GPBTypeSFixed64:
-      case GPBTypeSInt64:
-        switch (valueType) {
-          case GPBTypeBool:
-            dict = [[GPBInt64BoolDictionary alloc] init];
-            break;
-          case GPBTypeFixed32:
-          case GPBTypeUInt32:
-            dict = [[GPBInt64UInt32Dictionary alloc] init];
-            break;
-          case GPBTypeInt32:
-          case GPBTypeSFixed32:
-          case GPBTypeSInt32:
-            dict = [[GPBInt64Int32Dictionary alloc] init];
-            break;
-          case GPBTypeFixed64:
-          case GPBTypeUInt64:
-            dict = [[GPBInt64UInt64Dictionary alloc] init];
-            break;
-          case GPBTypeInt64:
-          case GPBTypeSFixed64:
-          case GPBTypeSInt64:
-            dict = [[GPBInt64Int64Dictionary alloc] init];
-            break;
-          case GPBTypeFloat:
-            dict = [[GPBInt64FloatDictionary alloc] init];
-            break;
-          case GPBTypeDouble:
-            dict = [[GPBInt64DoubleDictionary alloc] init];
-            break;
-          case GPBTypeEnum:
-            dict = [[GPBInt64EnumDictionary alloc]
-                initWithValidationFunction:field.enumDescriptor.enumVerifier];
-            break;
-          case GPBTypeData:
-          case GPBTypeMessage:
-          case GPBTypeString:
-            dict = [[GPBInt64ObjectDictionary alloc] init];
-            break;
-          case GPBTypeGroup:
-            NSCAssert(NO, @"shouldn't happen");
-            return nil;
-        }
-        break;
-      case GPBTypeString:
-        switch (valueType) {
-          case GPBTypeBool:
-            dict = [[GPBStringBoolDictionary alloc] init];
-            break;
-          case GPBTypeFixed32:
-          case GPBTypeUInt32:
-            dict = [[GPBStringUInt32Dictionary alloc] init];
-            break;
-          case GPBTypeInt32:
-          case GPBTypeSFixed32:
-          case GPBTypeSInt32:
-            dict = [[GPBStringInt32Dictionary alloc] init];
-            break;
-          case GPBTypeFixed64:
-          case GPBTypeUInt64:
-            dict = [[GPBStringUInt64Dictionary alloc] init];
-            break;
-          case GPBTypeInt64:
-          case GPBTypeSFixed64:
-          case GPBTypeSInt64:
-            dict = [[GPBStringInt64Dictionary alloc] init];
-            break;
-          case GPBTypeFloat:
-            dict = [[GPBStringFloatDictionary alloc] init];
-            break;
-          case GPBTypeDouble:
-            dict = [[GPBStringDoubleDictionary alloc] init];
-            break;
-          case GPBTypeEnum:
-            dict = [[GPBStringEnumDictionary alloc]
-                initWithValidationFunction:field.enumDescriptor.enumVerifier];
-            break;
-          case GPBTypeData:
-          case GPBTypeMessage:
-          case GPBTypeString:
-            dict = [[NSMutableDictionary alloc] init];
-            break;
-          case GPBTypeGroup:
-            NSCAssert(NO, @"shouldn't happen");
-            return nil;
-        }
-        break;
+    // No lock needed, this is called from places expecting to mutate
+    // so no threading protection is needed.
+    dict = CreateMapForField(field, nil);
+    GPBSetRetainedObjectIvarWithFieldInternal(self, field, dict, syntax);
+  }
+  return dict;
+}
 
-      case GPBTypeFloat:
-      case GPBTypeDouble:
-      case GPBTypeEnum:
-      case GPBTypeData:
-      case GPBTypeGroup:
-      case GPBTypeMessage:
-        NSCAssert(NO, @"shouldn't happen");
-        return nil;
+// This is like GPBGetObjectIvarWithField(), but for maps, it should
+// only be used to wire the method into the class.
+static id GetMapIvarWithField(GPBMessage *self, GPBFieldDescriptor *field) {
+  id dict = GPBGetObjectIvarWithFieldNoAutocreate(self, field);
+  if (!dict) {
+    // Check again after getting the lock.
+    OSSpinLockLock(&self->readOnlyMutex_);
+    dict = GPBGetObjectIvarWithFieldNoAutocreate(self, field);
+    if (!dict) {
+      dict = CreateMapForField(field, self);
+      GPBSetAutocreatedRetainedObjectIvarWithField(self, field, dict);
     }
-
-    GPBSetRetainedObjectIvarWithFieldInternal(self, field, dict, syntax);
+    OSSpinLockUnlock(&self->readOnlyMutex_);
   }
   return dict;
 }
@@ -595,7 +659,30 @@ void GPBAutocreatedArrayModified(GPBMessage *self, id array) {
       }
     }
   }
-  NSCAssert(NO, @"Unknown array.");
+  NSCAssert(NO, @"Unknown autocreated %@ for %@.", [array class], self);
+}
+
+void GPBAutocreatedDictionaryModified(GPBMessage *self, id dictionary) {
+  // When one of our autocreated dicts adds elements, make it visible.
+  GPBDescriptor *descriptor = [[self class] descriptor];
+  for (GPBFieldDescriptor *field in descriptor->fields_) {
+    if (field.fieldType == GPBFieldTypeMap) {
+      id curDict = GPBGetObjectIvarWithFieldNoAutocreate(self, field);
+      if (curDict == dictionary) {
+        if ((field.mapKeyType == GPBTypeString) &&
+            GPBFieldTypeIsObject(field)) {
+          GPBAutocreatedDictionary *autoDict = dictionary;
+          autoDict->_autocreator = nil;
+        } else {
+          GPBInt32Int32Dictionary *gpbDict = dictionary;
+          gpbDict->_autocreator = nil;
+        }
+        GPBBecomeVisibleToAutocreator(self);
+        return;
+      }
+    }
+  }
+  NSCAssert(NO, @"Unknown autocreated %@ for %@.", [dictionary class], self);
 }
 
 void GPBClearMessageAutocreator(GPBMessage *self) {
@@ -617,7 +704,8 @@ void GPBClearMessageAutocreator(GPBMessage *self) {
            : [self->autocreator_->autocreatedExtensionMap_
                  objectForKey:self->autocreatorExtension_]);
   NSCAssert(autocreatorHas || autocreatorFieldValue != self,
-            @"Cannot clear autocreator because it still refers to self.");
+            @"Cannot clear autocreator because it still refers to self, self: %@.",
+            self);
 
 #endif  // DEBUG && !defined(NS_BLOCK_ASSERTIONS)
 
@@ -636,26 +724,6 @@ static GPBUnknownFieldSet *GetOrMakeUnknownFields(GPBMessage *self) {
   return self->unknownFields_;
 }
 
-#ifdef DEBUG
-static void DebugRaiseExceptionIfNotInitialized(GPBMessage *message) {
-  if (!message.initialized) {
-    NSString *reason =
-        [NSString stringWithFormat:@"Uninitialized Message %@", message];
-    NSDictionary *userInfo =
-        message ? @{GPBExceptionMessageKey : message} : nil;
-    NSException *exception =
-        [NSException exceptionWithName:NSInternalInconsistencyException
-                                reason:reason
-                              userInfo:userInfo];
-    [exception raise];
-  }
-}
-#else
-GPB_INLINE void DebugRaiseExceptionIfNotInitialized(GPBMessage *message) {
-#pragma unused(message)
-}
-#endif  // DEBUG
-
 @implementation GPBMessage
 
 + (void)initialize {
@@ -663,14 +731,20 @@ GPB_INLINE void DebugRaiseExceptionIfNotInitialized(GPBMessage *message) {
   if ([self class] == pbMessageClass) {
     // This is here to start up the "base" class descriptor.
     [self descriptor];
+    // Message shares extension method resolving with GPBRootObject so insure
+    // it is started up at the same time.
+    (void)[GPBRootObject class];
   } else if ([self superclass] == pbMessageClass) {
     // This is here to start up all the "message" subclasses. Just needs to be
     // done for the messages, not any of the subclasses.
     // This must be done in initialize to enforce thread safety of start up of
-    // the protocol buffer library. All of the extension registries must be
-    // created in either "+load" or "+initialize".
+    // the protocol buffer library.
+    // Note: The generated code for -descriptor calls
+    // +[GPBDescriptor allocDescriptorForClass:...], passing the GPBRootObject
+    // subclass for the file.  That call chain is what ensures that *Root class
+    // is started up to support extension resolution off the message class
+    // (+resolveClassMethod: below) in a thread safe manner.
     [self descriptor];
-    [self extensionRegistry];
   }
 }
 
@@ -728,25 +802,63 @@ GPB_INLINE void DebugRaiseExceptionIfNotInitialized(GPBMessage *message) {
   return self;
 }
 
-- (instancetype)initWithData:(NSData *)data {
-  return [self initWithData:data extensionRegistry:nil];
+- (instancetype)initWithData:(NSData *)data error:(NSError **)errorPtr {
+  return [self initWithData:data extensionRegistry:nil error:errorPtr];
 }
 
 - (instancetype)initWithData:(NSData *)data
-           extensionRegistry:(GPBExtensionRegistry *)extensionRegistry {
+           extensionRegistry:(GPBExtensionRegistry *)extensionRegistry
+                       error:(NSError **)errorPtr {
   if ((self = [self init])) {
-    [self mergeFromData:data extensionRegistry:extensionRegistry];
-    DebugRaiseExceptionIfNotInitialized(self);
+    @try {
+      [self mergeFromData:data extensionRegistry:extensionRegistry];
+    }
+    @catch (NSException *exception) {
+      [self release];
+      self = nil;
+      if (errorPtr) {
+        *errorPtr = MessageErrorWithReason(GPBMessageErrorCodeMalformedData,
+                                           exception.reason);
+      }
+    }
+#ifdef DEBUG
+    if (self && !self.initialized) {
+      [self release];
+      self = nil;
+      if (errorPtr) {
+        *errorPtr = MessageError(GPBMessageErrorCodeMissingRequiredField, nil);
+      }
+    }
+#endif
   }
   return self;
 }
 
 - (instancetype)initWithCodedInputStream:(GPBCodedInputStream *)input
                        extensionRegistry:
-                           (GPBExtensionRegistry *)extensionRegistry {
+                           (GPBExtensionRegistry *)extensionRegistry
+                                   error:(NSError **)errorPtr {
   if ((self = [self init])) {
-    [self mergeFromCodedInputStream:input extensionRegistry:extensionRegistry];
-    DebugRaiseExceptionIfNotInitialized(self);
+    @try {
+      [self mergeFromCodedInputStream:input extensionRegistry:extensionRegistry];
+    }
+    @catch (NSException *exception) {
+      [self release];
+      self = nil;
+      if (errorPtr) {
+        *errorPtr = MessageErrorWithReason(GPBMessageErrorCodeMalformedData,
+                                           exception.reason);
+      }
+    }
+#ifdef DEBUG
+    if (self && !self.initialized) {
+      [self release];
+      self = nil;
+      if (errorPtr) {
+        *errorPtr = MessageError(GPBMessageErrorCodeMissingRequiredField, nil);
+      }
+    }
+#endif
   }
   return self;
 }
@@ -900,6 +1012,20 @@ GPB_INLINE void DebugRaiseExceptionIfNotInitialized(GPBMessage *message) {
               gpbArray->_autocreator = nil;
             }
           }
+        } else {
+          if ((field.mapKeyType == GPBTypeString) &&
+              GPBFieldTypeIsObject(field)) {
+            GPBAutocreatedDictionary *autoDict = arrayOrMap;
+            if (autoDict->_autocreator == self) {
+              autoDict->_autocreator = nil;
+            }
+          } else {
+            // Type doesn't matter, it is a GPB*Dictionary.
+            GPBInt32Int32Dictionary *gpbDict = arrayOrMap;
+            if (gpbDict->_autocreator == self) {
+              gpbDict->_autocreator = nil;
+            }
+          }
         }
         [arrayOrMap release];
       }
@@ -960,7 +1086,8 @@ GPB_INLINE void DebugRaiseExceptionIfNotInitialized(GPBMessage *message) {
           }
         } else {
           NSAssert(field.isOptional,
-                   @"If not required or optional, what was it?");
+                   @"%@: Single message field %@ not required or optional?",
+                   [self class], field.name);
           if (GPBGetHasIvarField(self, field)) {
             GPBMessage *message = GPBGetMessageIvarWithField(self, field);
             if (!message.initialized) {
@@ -1025,11 +1152,27 @@ GPB_INLINE void DebugRaiseExceptionIfNotInitialized(GPBMessage *message) {
 }
 
 - (NSData *)data {
-  DebugRaiseExceptionIfNotInitialized(self);
+#ifdef DEBUG
+  if (!self.initialized) {
+    return nil;
+  }
+#endif
   NSMutableData *data = [NSMutableData dataWithLength:[self serializedSize]];
   GPBCodedOutputStream *stream =
       [[GPBCodedOutputStream alloc] initWithData:data];
-  [self writeToCodedOutputStream:stream];
+  @try {
+    [self writeToCodedOutputStream:stream];
+  }
+  @catch (NSException *exception) {
+    // This really shouldn't happen. The only way writeToCodedOutputStream:
+    // could throw is if something in the library has a bug and the
+    // serializedSize was wrong.
+#ifdef DEBUG
+    NSLog(@"%@: Internal exception while building message data: %@",
+          [self class], exception);
+#endif
+    data = nil;
+  }
   [stream release];
   return data;
 }
@@ -1041,7 +1184,19 @@ GPB_INLINE void DebugRaiseExceptionIfNotInitialized(GPBMessage *message) {
       [NSMutableData dataWithLength:(serializedSize + varintSize)];
   GPBCodedOutputStream *stream =
       [[GPBCodedOutputStream alloc] initWithData:data];
-  [self writeDelimitedToCodedOutputStream:stream];
+  @try {
+    [self writeDelimitedToCodedOutputStream:stream];
+  }
+  @catch (NSException *exception) {
+    // This really shouldn't happen.  The only way writeToCodedOutputStream:
+    // could throw is if something in the library has a bug and the
+    // serializedSize was wrong.
+#ifdef DEBUG
+    NSLog(@"%@: Internal exception while building message delimitedData: %@",
+          [self class], exception);
+#endif
+    data = nil;
+  }
   [stream release];
   return data;
 }
@@ -1717,32 +1872,55 @@ GPB_INLINE void DebugRaiseExceptionIfNotInitialized(GPBMessage *message) {
 
 #pragma mark - Parse From Data Support
 
-+ (instancetype)parseFromData:(NSData *)data {
-  return [self parseFromData:data extensionRegistry:nil];
++ (instancetype)parseFromData:(NSData *)data error:(NSError **)errorPtr {
+  return [self parseFromData:data extensionRegistry:nil error:errorPtr];
 }
 
 + (instancetype)parseFromData:(NSData *)data
-            extensionRegistry:(GPBExtensionRegistry *)extensionRegistry {
+            extensionRegistry:(GPBExtensionRegistry *)extensionRegistry
+                        error:(NSError **)errorPtr {
   return [[[self alloc] initWithData:data
-                   extensionRegistry:extensionRegistry] autorelease];
+                   extensionRegistry:extensionRegistry
+                               error:errorPtr] autorelease];
 }
 
 + (instancetype)parseFromCodedInputStream:(GPBCodedInputStream *)input
-                        extensionRegistry:(GPBExtensionRegistry *)extensionRegistry {
+                        extensionRegistry:(GPBExtensionRegistry *)extensionRegistry
+                                    error:(NSError **)errorPtr {
   return
       [[[self alloc] initWithCodedInputStream:input
-                            extensionRegistry:extensionRegistry] autorelease];
+                            extensionRegistry:extensionRegistry
+                                        error:errorPtr] autorelease];
 }
 
 #pragma mark - Parse Delimited From Data Support
 
 + (instancetype)parseDelimitedFromCodedInputStream:(GPBCodedInputStream *)input
                                  extensionRegistry:
-                                     (GPBExtensionRegistry *)extensionRegistry {
+                                     (GPBExtensionRegistry *)extensionRegistry
+                                             error:(NSError **)errorPtr {
   GPBMessage *message = [[[self alloc] init] autorelease];
-  [message mergeDelimitedFromCodedInputStream:input
-                            extensionRegistry:extensionRegistry];
-  DebugRaiseExceptionIfNotInitialized(message);
+  @try {
+    [message mergeDelimitedFromCodedInputStream:input
+                              extensionRegistry:extensionRegistry];
+  }
+  @catch (NSException *exception) {
+    [message release];
+    message = nil;
+    if (errorPtr) {
+      *errorPtr = MessageErrorWithReason(GPBMessageErrorCodeMalformedData,
+                                         exception.reason);
+    }
+  }
+#ifdef DEBUG
+  if (message && !message.initialized) {
+    [message release];
+    message = nil;
+    if (errorPtr) {
+      *errorPtr = MessageError(GPBMessageErrorCodeMissingRequiredField, nil);
+    }
+  }
+#endif
   return message;
 }
 
@@ -4661,7 +4839,9 @@ static BOOL IvarSetEnum(GPBFieldDescriptor *field, void *voidContext) {
         context.impToAdd = imp_implementationWithBlock(^(id obj, BOOL value) {
           if (value) {
             [NSException raise:NSInvalidArgumentException
-                        format:@"has fields can only be set to NO"];
+                        format:@"%@: %@ can only be set to NO (to clear field).",
+                               [obj class],
+                               NSStringFromSelector(field->setHasSel_)];
           }
           GPBClearMessageField(obj, field);
         });
@@ -4684,9 +4864,15 @@ static BOOL IvarSetEnum(GPBFieldDescriptor *field, void *voidContext) {
       }
     } else {
       if (sel == field->getSel_) {
-        context.impToAdd = imp_implementationWithBlock(^(id obj) {
-          return GetArrayIvarWithField(obj, field);
-        });
+        if (field.fieldType == GPBFieldTypeRepeated) {
+          context.impToAdd = imp_implementationWithBlock(^(id obj) {
+            return GetArrayIvarWithField(obj, field);
+          });
+        } else {
+          context.impToAdd = imp_implementationWithBlock(^(id obj) {
+            return GetMapIvarWithField(obj, field);
+          });
+        }
         context.encodingSelector = @selector(getArray);
         break;
       } else if (sel == field->setSel_) {
@@ -4711,18 +4897,37 @@ static BOOL IvarSetEnum(GPBFieldDescriptor *field, void *voidContext) {
   return [super resolveInstanceMethod:sel];
 }
 
++ (BOOL)resolveClassMethod:(SEL)sel {
+  // Extensions scoped to a Message and looked up via class methods.
+  if (GPBResolveExtensionClassMethod(self, sel)) {
+    return YES;
+  }
+  return [super resolveClassMethod:sel];
+}
+
 #pragma mark - NSCoding Support
 
++ (BOOL)supportsSecureCoding {
+  return YES;
+}
+
 - (instancetype)initWithCoder:(NSCoder *)aDecoder {
   self = [self init];
   if (self) {
-    [self mergeFromData:[aDecoder decodeDataObject] extensionRegistry:nil];
+    NSData *data =
+        [aDecoder decodeObjectOfClass:[NSData class] forKey:kGPBDataCoderKey];
+    if (data.length) {
+      [self mergeFromData:data extensionRegistry:nil];
+    }
   }
   return self;
 }
 
 - (void)encodeWithCoder:(NSCoder *)aCoder {
-  [aCoder encodeDataObject:[self data]];
+  NSData *data = [self data];
+  if (data.length) {
+    [aCoder encodeObject:data forKey:kGPBDataCoderKey];
+  }
 }
 
 #pragma mark - KVC Support
diff --git a/objectivec/GPBMessage_PackagePrivate.h b/objectivec/GPBMessage_PackagePrivate.h
index f2a3d5fa..c437c55b 100644
--- a/objectivec/GPBMessage_PackagePrivate.h
+++ b/objectivec/GPBMessage_PackagePrivate.h
@@ -82,6 +82,7 @@ typedef struct GPBMessage_Storage *GPBMessage_StoragePtr;
 // -[CodedInputStream checkLastTagWas:] after calling this to
 // verify that the last tag seen was the appropriate end-group tag,
 // or zero for EOF.
+// NOTE: This will throw if there is an error while parsing.
 - (void)mergeFromCodedInputStream:(GPBCodedInputStream *)input
                 extensionRegistry:(GPBExtensionRegistry *)extensionRegistry;
 
@@ -113,9 +114,10 @@ BOOL GPBWasMessageAutocreatedBy(GPBMessage *message, GPBMessage *parent);
 // visible to its autocreator.
 void GPBBecomeVisibleToAutocreator(GPBMessage *self);
 
-// Call this when an array is mutabled so the parent message that autocreated
-// it can react.
+// Call this when an array/dictionary is mutated so the parent message that
+// autocreated it can react.
 void GPBAutocreatedArrayModified(GPBMessage *self, id array);
+void GPBAutocreatedDictionaryModified(GPBMessage *self, id dictionary);
 
 // Clear the autocreator, if any. Asserts if the autocreator still has an
 // autocreated reference to this message.
diff --git a/objectivec/GPBProtocolBuffers_RuntimeSupport.h b/objectivec/GPBProtocolBuffers_RuntimeSupport.h
index ac3226ef..7fd7b4c8 100644
--- a/objectivec/GPBProtocolBuffers_RuntimeSupport.h
+++ b/objectivec/GPBProtocolBuffers_RuntimeSupport.h
@@ -35,7 +35,7 @@
 
 #import "GPBDescriptor_PackagePrivate.h"
 #import "GPBExtensionField_PackagePrivate.h"
-#import "GPBExtensionRegistry_PackagePrivate.h"
+#import "GPBExtensionRegistry.h"
 #import "GPBMessage_PackagePrivate.h"
 #import "GPBRootObject_PackagePrivate.h"
 #import "GPBUtilities_PackagePrivate.h"
diff --git a/objectivec/GPBRootObject.m b/objectivec/GPBRootObject.m
index b58f95ce..38dab665 100644
--- a/objectivec/GPBRootObject.m
+++ b/objectivec/GPBRootObject.m
@@ -31,6 +31,7 @@
 #import "GPBRootObject_PackagePrivate.h"
 
 #import <objc/runtime.h>
+#import <libkern/OSAtomic.h>
 
 #import <CoreFoundation/CoreFoundation.h>
 
@@ -95,9 +96,11 @@ static CFHashCode GPBRootExtensionKeyHash(const void *value) {
   return jenkins_one_at_a_time_hash(key);
 }
 
+static OSSpinLock gExtensionSingletonDictionaryLock_ = OS_SPINLOCK_INIT;
 static CFMutableDictionaryRef gExtensionSingletonDictionary = NULL;
 
 + (void)initialize {
+  // Ensure the global is started up.
   if (!gExtensionSingletonDictionary) {
     CFDictionaryKeyCallBacks keyCallBacks = {
       // See description above for reason for using custom dictionary.
@@ -112,6 +115,13 @@ static CFMutableDictionaryRef gExtensionSingletonDictionary = NULL;
         CFDictionaryCreateMutable(kCFAllocatorDefault, 0, &keyCallBacks,
                                   &kCFTypeDictionaryValueCallBacks);
   }
+
+  if ([self superclass] == [GPBRootObject class]) {
+    // This is here to start up all the per file "Root" subclasses.
+    // This must be done in initialize to enforce thread safety of start up of
+    // the protocol buffer library.
+    [self extensionRegistry];
+  }
 }
 
 + (GPBExtensionRegistry *)extensionRegistry {
@@ -122,39 +132,54 @@ static CFMutableDictionaryRef gExtensionSingletonDictionary = NULL;
 
 + (void)globallyRegisterExtension:(GPBExtensionField *)field {
   const char *key = [field.descriptor singletonNameC];
-  // Register happens at startup, so there is no thread safety issue in
-  // modifying the dictionary.
+  OSSpinLockLock(&gExtensionSingletonDictionaryLock_);
   CFDictionarySetValue(gExtensionSingletonDictionary, key, field);
+  OSSpinLockUnlock(&gExtensionSingletonDictionaryLock_);
 }
 
-static id ExtensionForName(id self, SEL _cmd) {
+GPB_INLINE id ExtensionForName(id self, SEL _cmd) {
   // Really fast way of doing "classname_selName".
   // This came up as a hotspot (creation of NSString *) when accessing a
   // lot of extensions.
-  const char *className = class_getName(self);
   const char *selName = sel_getName(_cmd);
+  if (selName[0] == '_') {
+    return nil;  // Apple internal selector.
+  }
+  size_t selNameLen = 0;
+  while (1) {
+    char c = selName[selNameLen];
+    if (c == '\0') {  // String end.
+      break;
+    }
+    if (c == ':') {
+      return nil;  // Selector took an arg, not one of the runtime methods.
+    }
+    ++selNameLen;
+  }
+
+  const char *className = class_getName(self);
   size_t classNameLen = strlen(className);
-  size_t selNameLen = strlen(selName);
   char key[classNameLen + selNameLen + 2];
   memcpy(key, className, classNameLen);
   key[classNameLen] = '_';
   memcpy(&key[classNameLen + 1], selName, selNameLen);
   key[classNameLen + 1 + selNameLen] = '\0';
+  OSSpinLockLock(&gExtensionSingletonDictionaryLock_);
   id extension = (id)CFDictionaryGetValue(gExtensionSingletonDictionary, key);
-  // We can't remove the key from the dictionary here (as an optimization),
-  // because resolveClassMethod can happen on any thread and we'd then need
-  // a lock.
+  if (extension) {
+    // The method is getting wired in to the class, so no need to keep it in
+    // the dictionary.
+    CFDictionaryRemoveValue(gExtensionSingletonDictionary, key);
+  }
+  OSSpinLockUnlock(&gExtensionSingletonDictionaryLock_);
   return extension;
 }
 
-+ (BOOL)resolveClassMethod:(SEL)sel {
+BOOL GPBResolveExtensionClassMethod(Class self, SEL sel) {
   // Another option would be to register the extensions with the class at
   // globallyRegisterExtension:
   // Timing the two solutions, this solution turned out to be much faster
   // and reduced startup time, and runtime memory.
-  // On an iPhone 5s:
-  // ResolveClassMethod: 1515583 nanos
-  // globallyRegisterExtension: 2453083 nanos
   // The advantage to globallyRegisterExtension is that it would reduce the
   // size of the protos somewhat because the singletonNameC wouldn't need
   // to include the class name. For a class with a lot of extensions it
@@ -169,7 +194,17 @@ static id ExtensionForName(id self, SEL _cmd) {
 #pragma unused(obj)
       return extension;
     });
-    return class_addMethod(metaClass, sel, imp, encoding);
+    if (class_addMethod(metaClass, sel, imp, encoding)) {
+      return YES;
+    }
+  }
+  return NO;
+}
+
+
++ (BOOL)resolveClassMethod:(SEL)sel {
+  if (GPBResolveExtensionClassMethod(self, sel)) {
+    return YES;
   }
   return [super resolveClassMethod:sel];
 }
diff --git a/objectivec/GPBRootObject_PackagePrivate.h b/objectivec/GPBRootObject_PackagePrivate.h
index 4e1d3913..f1cfe990 100644
--- a/objectivec/GPBRootObject_PackagePrivate.h
+++ b/objectivec/GPBRootObject_PackagePrivate.h
@@ -40,3 +40,7 @@
 + (void)globallyRegisterExtension:(GPBExtensionField *)field;
 
 @end
+
+// Returns YES if the selector was resolved and added to the class,
+// NO otherwise.
+BOOL GPBResolveExtensionClassMethod(Class self, SEL sel);
diff --git a/objectivec/GPBUtilities.m b/objectivec/GPBUtilities.m
index 09e34bfb..f912b979 100644
--- a/objectivec/GPBUtilities.m
+++ b/objectivec/GPBUtilities.m
@@ -93,7 +93,9 @@ void GPBClearMessageField(GPBMessage *self, GPBFieldDescriptor *field) {
 }
 
 BOOL GPBGetHasIvar(GPBMessage *self, int32_t idx, uint32_t fieldNumber) {
-  NSCAssert(self->messageStorage_ != NULL, @"How?");
+  NSCAssert(self->messageStorage_ != NULL,
+            @"%@: All messages should have storage (from init)",
+            [self class]);
   if (idx < 0) {
     NSCAssert(fieldNumber != 0, @"Invalid field number.");
     BOOL hasIvar = (self->messageStorage_->_has_storage_[-idx] == fieldNumber);
@@ -109,7 +111,8 @@ BOOL GPBGetHasIvar(GPBMessage *self, int32_t idx, uint32_t fieldNumber) {
 }
 
 uint32_t GPBGetHasOneof(GPBMessage *self, int32_t idx) {
-  NSCAssert(idx < 0, @"invalid index for oneof.");
+  NSCAssert(idx < 0, @"%@: invalid index (%d) for oneof.",
+            [self class], idx);
   uint32_t result = self->messageStorage_->_has_storage_[-idx];
   return result;
 }
@@ -145,7 +148,9 @@ void GPBMaybeClearOneof(GPBMessage *self, GPBOneofDescriptor *oneof,
   // Like GPBClearMessageField(), free the memory if an objecttype is set,
   // pod types don't need to do anything.
   GPBFieldDescriptor *fieldSet = [oneof fieldWithNumber:fieldNumberSet];
-  NSCAssert(fieldSet, @"oneof set to something not in the oneof?");
+  NSCAssert(fieldSet,
+            @"%@: oneof set to something (%u) not in the oneof?",
+            [self class], fieldNumberSet);
   if (fieldSet && GPBFieldStoresObject(fieldSet)) {
     uint8_t *storage = (uint8_t *)self->messageStorage_;
     id *typePtr = (id *)&storage[fieldSet->description_->offset];
@@ -189,7 +194,9 @@ void GPBMaybeClearOneof(GPBMessage *self, GPBOneofDescriptor *oneof,
 //%  if (oneof) {
 //%    GPBMaybeClearOneof(self, oneof, GPBFieldNumber(field));
 //%  }
-//%  NSCAssert(self->messageStorage_ != NULL, @"How?");
+//%  NSCAssert(self->messageStorage_ != NULL,
+//%            @"%@: All messages should have storage (from init)",
+//%            [self class]);
 //%#if defined(__clang_analyzer__)
 //%  if (self->messageStorage_ == NULL) return;
 //%#endif
@@ -263,7 +270,9 @@ void GPBSetObjectIvarWithFieldInternal(GPBMessage *self,
 void GPBSetRetainedObjectIvarWithFieldInternal(GPBMessage *self,
                                                GPBFieldDescriptor *field,
                                                id value, GPBFileSyntax syntax) {
-  NSCAssert(self->messageStorage_ != NULL, @"How?");
+  NSCAssert(self->messageStorage_ != NULL,
+            @"%@: All messages should have storage (from init)",
+            [self class]);
 #if defined(__clang_analyzer__)
   if (self->messageStorage_ == NULL) return;
 #endif
@@ -328,7 +337,7 @@ void GPBSetRetainedObjectIvarWithFieldInternal(GPBMessage *self,
   if (oldValue) {
     if (isMapOrArray) {
       if (field.fieldType == GPBFieldTypeRepeated) {
-        // If the old message value was autocreated by us, then clear it.
+        // If the old array was autocreated by us, then clear it.
         if (GPBTypeIsObject(fieldType)) {
           GPBAutocreatedArray *autoArray = oldValue;
           if (autoArray->_autocreator == self) {
@@ -341,6 +350,21 @@ void GPBSetRetainedObjectIvarWithFieldInternal(GPBMessage *self,
             gpbArray->_autocreator = nil;
           }
         }
+      } else { // GPBFieldTypeMap
+        // If the old map was autocreated by us, then clear it.
+        if ((field.mapKeyType == GPBTypeString) &&
+            GPBTypeIsObject(fieldType)) {
+          GPBAutocreatedDictionary *autoDict = oldValue;
+          if (autoDict->_autocreator == self) {
+            autoDict->_autocreator = nil;
+          }
+        } else {
+          // Type doesn't matter, it is a GPB*Dictionary.
+          GPBInt32Int32Dictionary *gpbDict = oldValue;
+          if (gpbDict->_autocreator == self) {
+            gpbDict->_autocreator = nil;
+          }
+        }
       }
     } else if (fieldIsMessage) {
       // If the old message value was autocreated by us, then clear it.
@@ -461,7 +485,9 @@ void GPBSetBoolIvarWithFieldInternal(GPBMessage *self,
   if (oneof) {
     GPBMaybeClearOneof(self, oneof, GPBFieldNumber(field));
   }
-  NSCAssert(self->messageStorage_ != NULL, @"How?");
+  NSCAssert(self->messageStorage_ != NULL,
+            @"%@: All messages should have storage (from init)",
+            [self class]);
 #if defined(__clang_analyzer__)
   if (self->messageStorage_ == NULL) return;
 #endif
@@ -507,7 +533,9 @@ void GPBSetInt32IvarWithFieldInternal(GPBMessage *self,
   if (oneof) {
     GPBMaybeClearOneof(self, oneof, GPBFieldNumber(field));
   }
-  NSCAssert(self->messageStorage_ != NULL, @"How?");
+  NSCAssert(self->messageStorage_ != NULL,
+            @"%@: All messages should have storage (from init)",
+            [self class]);
 #if defined(__clang_analyzer__)
   if (self->messageStorage_ == NULL) return;
 #endif
@@ -553,7 +581,9 @@ void GPBSetUInt32IvarWithFieldInternal(GPBMessage *self,
   if (oneof) {
     GPBMaybeClearOneof(self, oneof, GPBFieldNumber(field));
   }
-  NSCAssert(self->messageStorage_ != NULL, @"How?");
+  NSCAssert(self->messageStorage_ != NULL,
+            @"%@: All messages should have storage (from init)",
+            [self class]);
 #if defined(__clang_analyzer__)
   if (self->messageStorage_ == NULL) return;
 #endif
@@ -599,7 +629,9 @@ void GPBSetInt64IvarWithFieldInternal(GPBMessage *self,
   if (oneof) {
     GPBMaybeClearOneof(self, oneof, GPBFieldNumber(field));
   }
-  NSCAssert(self->messageStorage_ != NULL, @"How?");
+  NSCAssert(self->messageStorage_ != NULL,
+            @"%@: All messages should have storage (from init)",
+            [self class]);
 #if defined(__clang_analyzer__)
   if (self->messageStorage_ == NULL) return;
 #endif
@@ -645,7 +677,9 @@ void GPBSetUInt64IvarWithFieldInternal(GPBMessage *self,
   if (oneof) {
     GPBMaybeClearOneof(self, oneof, GPBFieldNumber(field));
   }
-  NSCAssert(self->messageStorage_ != NULL, @"How?");
+  NSCAssert(self->messageStorage_ != NULL,
+            @"%@: All messages should have storage (from init)",
+            [self class]);
 #if defined(__clang_analyzer__)
   if (self->messageStorage_ == NULL) return;
 #endif
@@ -691,7 +725,9 @@ void GPBSetFloatIvarWithFieldInternal(GPBMessage *self,
   if (oneof) {
     GPBMaybeClearOneof(self, oneof, GPBFieldNumber(field));
   }
-  NSCAssert(self->messageStorage_ != NULL, @"How?");
+  NSCAssert(self->messageStorage_ != NULL,
+            @"%@: All messages should have storage (from init)",
+            [self class]);
 #if defined(__clang_analyzer__)
   if (self->messageStorage_ == NULL) return;
 #endif
@@ -737,7 +773,9 @@ void GPBSetDoubleIvarWithFieldInternal(GPBMessage *self,
   if (oneof) {
     GPBMaybeClearOneof(self, oneof, GPBFieldNumber(field));
   }
-  NSCAssert(self->messageStorage_ != NULL, @"How?");
+  NSCAssert(self->messageStorage_ != NULL,
+            @"%@: All messages should have storage (from init)",
+            [self class]);
 #if defined(__clang_analyzer__)
   if (self->messageStorage_ == NULL) return;
 #endif
@@ -1152,30 +1190,32 @@ static void AppendTextFormatForMessageField(GPBMessage *message,
                                             GPBFieldDescriptor *field,
                                             NSMutableString *toStr,
                                             NSString *lineIndent) {
-  id array;
-  NSUInteger arrayCount;
+  id arrayOrMap;
+  NSUInteger count;
   GPBFieldType fieldType = field.fieldType;
   switch (fieldType) {
     case GPBFieldTypeSingle:
-      array = nil;
-      arrayCount = (GPBGetHasIvarField(message, field) ? 1 : 0);
+      arrayOrMap = nil;
+      count = (GPBGetHasIvarField(message, field) ? 1 : 0);
       break;
 
     case GPBFieldTypeRepeated:
-      array = GPBGetObjectIvarWithFieldNoAutocreate(message, field);
-      arrayCount = [(NSArray *)array count];
+      // Will be NSArray or GPB*Array, type doesn't matter, they both
+      // implement count.
+      arrayOrMap = GPBGetObjectIvarWithFieldNoAutocreate(message, field);
+      count = [(NSArray *)arrayOrMap count];
       break;
 
     case GPBFieldTypeMap: {
-      // Could be a GPB*Dictionary or NSMutableDictionary, type doesn't matter,
-      // just want count.
-      array = GPBGetObjectIvarWithFieldNoAutocreate(message, field);
-      arrayCount = [(NSArray *)array count];
+      // Will be GPB*Dictionary or NSMutableDictionary, type doesn't matter,
+      // they both implement count.
+      arrayOrMap = GPBGetObjectIvarWithFieldNoAutocreate(message, field);
+      count = [(NSDictionary *)arrayOrMap count];
       break;
     }
   }
 
-  if (arrayCount == 0) {
+  if (count == 0) {
     // Nothing to print, out of here.
     return;
   }
@@ -1189,7 +1229,7 @@ static void AppendTextFormatForMessageField(GPBMessage *message,
     fieldName = [NSString stringWithFormat:@"%u", GPBFieldNumber(field)];
     // If there is only one entry, put the objc name as a comment, other wise
     // add it before the the repeated values.
-    if (arrayCount > 1) {
+    if (count > 1) {
       [toStr appendFormat:@"%@# %@\n", lineIndent, field.name];
     } else {
       lineEnding = [NSString stringWithFormat:@"  # %@", field.name];
@@ -1197,16 +1237,17 @@ static void AppendTextFormatForMessageField(GPBMessage *message,
   }
 
   if (fieldType == GPBFieldTypeMap) {
-    AppendTextFormatForMapMessageField(array, field, toStr, lineIndent,
+    AppendTextFormatForMapMessageField(arrayOrMap, field, toStr, lineIndent,
                                        fieldName, lineEnding);
     return;
   }
 
+  id array = arrayOrMap;
   const BOOL isRepeated = (array != nil);
 
   GPBType fieldDataType = GPBGetFieldType(field);
   BOOL isMessageField = GPBTypeIsMessage(fieldDataType);
-  for (NSUInteger j = 0; j < arrayCount; ++j) {
+  for (NSUInteger j = 0; j < count; ++j) {
     // Start the line.
     [toStr appendFormat:@"%@%@%s ", lineIndent, fieldName,
                         (isMessageField ? "" : ":")];
@@ -1291,7 +1332,7 @@ static void AppendTextFormatForMessageField(GPBMessage *message,
     // End the line.
     [toStr appendFormat:@"%@\n", lineEnding];
 
-  }  // for(arrayCount)
+  }  // for(count)
 }
 
 static void AppendTextFormatForMessageExtensionRange(GPBMessage *message,
diff --git a/objectivec/ProtocolBuffers_OSX.xcodeproj/project.pbxproj b/objectivec/ProtocolBuffers_OSX.xcodeproj/project.pbxproj
index 46416043..f18ba2f8 100644
--- a/objectivec/ProtocolBuffers_OSX.xcodeproj/project.pbxproj
+++ b/objectivec/ProtocolBuffers_OSX.xcodeproj/project.pbxproj
@@ -200,7 +200,6 @@
 		F4B6B8AF1A9CC98000892426 /* GPBField_PackagePrivate.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = GPBField_PackagePrivate.h; sourceTree = "<group>"; };
 		F4B6B8B21A9CCBDA00892426 /* GPBUnknownFieldSet_PackagePrivate.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = GPBUnknownFieldSet_PackagePrivate.h; sourceTree = "<group>"; };
 		F4B6B8B61A9CD1DE00892426 /* GPBExtensionField_PackagePrivate.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = GPBExtensionField_PackagePrivate.h; sourceTree = "<group>"; };
-		F4B6B8B71A9CD1DE00892426 /* GPBExtensionRegistry_PackagePrivate.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = GPBExtensionRegistry_PackagePrivate.h; sourceTree = "<group>"; };
 		F4B6B8B81A9CD1DE00892426 /* GPBRootObject_PackagePrivate.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = GPBRootObject_PackagePrivate.h; sourceTree = "<group>"; };
 		F4B6B8B91A9D338B00892426 /* unittest_name_mangling.proto */ = {isa = PBXFileReference; lastKnownFileType = text; path = unittest_name_mangling.proto; sourceTree = "<group>"; };
 /* End PBXFileReference section */
@@ -301,7 +300,6 @@
 				F4B6B8B61A9CD1DE00892426 /* GPBExtensionField_PackagePrivate.h */,
 				748F0CAF0FD70602000858A9 /* GPBExtensionField.h */,
 				F45C69CB16DFD08D0081955B /* GPBExtensionField.m */,
-				F4B6B8B71A9CD1DE00892426 /* GPBExtensionRegistry_PackagePrivate.h */,
 				7461B4A80F94F99000A0C422 /* GPBExtensionRegistry.h */,
 				7461B4A90F94F99000A0C422 /* GPBExtensionRegistry.m */,
 				F4B6B8B81A9CD1DE00892426 /* GPBRootObject_PackagePrivate.h */,
@@ -595,7 +593,7 @@
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 			shellPath = /bin/bash;
-			shellScript = "set -eu\nmkdir -p \"${PROJECT_DERIVED_FILE_DIR}/protos\"\nexport PATH=\"${PATH}:.\"\ncd \"${SRCROOT}\"/../src\n\nPROTOC=./protoc\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_custom_options.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_enormous_descriptor.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_embed_optimize_for.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_empty.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_import.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_import_lite.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_lite.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_mset.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_no_generic_services.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_optimize_for.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_import_public.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_import_public_lite.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_drop_unknown_fields.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_preserve_unknown_enum.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/map_lite_unittest.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/map_proto2_unittest.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/map_unittest.proto\n\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. --proto_path=\"${SRCROOT}\"/Tests \"${SRCROOT}\"/Tests/unittest_objc.proto\n\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=\"${SRCROOT}\"/Tests \"${SRCROOT}\"/Tests/unittest_cycle.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=\"${SRCROOT}\"/Tests \"${SRCROOT}\"/Tests/unittest_name_mangling.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=\"${SRCROOT}\"/Tests \"${SRCROOT}\"/Tests/unittest_runtime_proto2.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=\"${SRCROOT}\"/Tests \"${SRCROOT}\"/Tests/unittest_runtime_proto3.proto\n\nexport GPB_CLASSLIST_PATH=\"${PROJECT_DERIVED_FILE_DIR}/ClassList.txt\"\nexport GPB_OBJC_CLASS_WHITELIST_PATHS=\"${SRCROOT}/Tests/Filter1.txt;${SRCROOT}/Tests/Filter2.txt\"\n\nif [ -e ${GPB_CLASSLIST_PATH} ]; then\nrm ${GPB_CLASSLIST_PATH}\nfi\n\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=\"${SRCROOT}\"/Tests \"${SRCROOT}\"/Tests/unittest_filter.proto\n\n";
+			shellScript = "set -eu\nmkdir -p \"${PROJECT_DERIVED_FILE_DIR}/protos\"\nexport PATH=\"${PATH}:.\"\ncd \"${SRCROOT}\"/../src\n\nPROTOC=./protoc\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_custom_options.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_enormous_descriptor.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_embed_optimize_for.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_empty.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_import.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_import_lite.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_lite.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_mset.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_no_generic_services.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_optimize_for.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_import_public.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_import_public_lite.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_drop_unknown_fields.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_preserve_unknown_enum.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/map_lite_unittest.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/map_proto2_unittest.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/map_unittest.proto\n\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. --proto_path=\"${SRCROOT}\"/Tests \"${SRCROOT}\"/Tests/unittest_objc.proto\n\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=\"${SRCROOT}\"/Tests \"${SRCROOT}\"/Tests/unittest_cycle.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=\"${SRCROOT}\"/Tests \"${SRCROOT}\"/Tests/unittest_name_mangling.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=\"${SRCROOT}\"/Tests \"${SRCROOT}\"/Tests/unittest_runtime_proto2.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=\"${SRCROOT}\"/Tests \"${SRCROOT}\"/Tests/unittest_runtime_proto3.proto\n\n# Use the filter\nexport GPB_OBJC_CLASS_WHITELIST_PATHS=\"${SRCROOT}/Tests/Filter1.txt;${SRCROOT}/Tests/Filter2.txt\"\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=\"${SRCROOT}\"/Tests \"${SRCROOT}\"/Tests/unittest_filter.proto\n\n";
 			showEnvVarsInLog = 0;
 		};
 		F4B62A781AF91F6000AFCEDC /* Script: Check Runtime Stamps */ = {
@@ -819,6 +817,7 @@
 				CLANG_WARN_OBJC_MISSING_PROPERTY_SYNTHESIS = YES;
 				CLANG_WARN_SUSPICIOUS_IMPLICIT_CONVERSION = YES;
 				CLANG_WARN__DUPLICATE_METHOD_MATCH = YES;
+				ENABLE_NS_ASSERTIONS = NO;
 				GCC_C_LANGUAGE_STANDARD = c99;
 				GCC_TREAT_IMPLICIT_FUNCTION_DECLARATIONS_AS_ERRORS = YES;
 				GCC_TREAT_INCOMPATIBLE_POINTER_TYPE_WARNINGS_AS_ERRORS = YES;
diff --git a/objectivec/ProtocolBuffers_OSX.xcodeproj/xcshareddata/xcschemes/ProtocolBuffers.xcscheme b/objectivec/ProtocolBuffers_OSX.xcodeproj/xcshareddata/xcschemes/ProtocolBuffers.xcscheme
index f6f6e12b..617fb47f 100644
--- a/objectivec/ProtocolBuffers_OSX.xcodeproj/xcshareddata/xcschemes/ProtocolBuffers.xcscheme
+++ b/objectivec/ProtocolBuffers_OSX.xcodeproj/xcshareddata/xcschemes/ProtocolBuffers.xcscheme
@@ -34,6 +34,20 @@
                ReferencedContainer = "container:ProtocolBuffers_OSX.xcodeproj">
             </BuildableReference>
          </BuildActionEntry>
+         <BuildActionEntry
+            buildForTesting = "YES"
+            buildForRunning = "NO"
+            buildForProfiling = "NO"
+            buildForArchiving = "NO"
+            buildForAnalyzing = "YES">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "8BBEA4A5147C727100C4ADB7"
+               BuildableName = "UnitTests.xctest"
+               BlueprintName = "UnitTests"
+               ReferencedContainer = "container:ProtocolBuffers_OSX.xcodeproj">
+            </BuildableReference>
+         </BuildActionEntry>
       </BuildActionEntries>
    </BuildAction>
    <TestAction
diff --git a/objectivec/ProtocolBuffers_iOS.xcodeproj/project.pbxproj b/objectivec/ProtocolBuffers_iOS.xcodeproj/project.pbxproj
index 7cf41359..d6e621e6 100644
--- a/objectivec/ProtocolBuffers_iOS.xcodeproj/project.pbxproj
+++ b/objectivec/ProtocolBuffers_iOS.xcodeproj/project.pbxproj
@@ -224,7 +224,6 @@
 		F4B6B8B01A9CC99500892426 /* GPBField_PackagePrivate.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = GPBField_PackagePrivate.h; sourceTree = "<group>"; };
 		F4B6B8B11A9CCBBB00892426 /* GPBUnknownFieldSet_PackagePrivate.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = GPBUnknownFieldSet_PackagePrivate.h; sourceTree = "<group>"; };
 		F4B6B8B31A9CD1C600892426 /* GPBExtensionField_PackagePrivate.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = GPBExtensionField_PackagePrivate.h; sourceTree = "<group>"; };
-		F4B6B8B41A9CD1C600892426 /* GPBExtensionRegistry_PackagePrivate.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = GPBExtensionRegistry_PackagePrivate.h; sourceTree = "<group>"; };
 		F4B6B8B51A9CD1C600892426 /* GPBRootObject_PackagePrivate.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = GPBRootObject_PackagePrivate.h; sourceTree = "<group>"; };
 		F4B6B8BA1A9D343B00892426 /* unittest_name_mangling.proto */ = {isa = PBXFileReference; lastKnownFileType = text; path = unittest_name_mangling.proto; sourceTree = "<group>"; };
 /* End PBXFileReference section */
@@ -339,7 +338,6 @@
 				F4B6B8B31A9CD1C600892426 /* GPBExtensionField_PackagePrivate.h */,
 				748F0CAF0FD70602000858A9 /* GPBExtensionField.h */,
 				F45C69CB16DFD08D0081955B /* GPBExtensionField.m */,
-				F4B6B8B41A9CD1C600892426 /* GPBExtensionRegistry_PackagePrivate.h */,
 				7461B4A80F94F99000A0C422 /* GPBExtensionRegistry.h */,
 				7461B4A90F94F99000A0C422 /* GPBExtensionRegistry.m */,
 				F4B6B8B51A9CD1C600892426 /* GPBRootObject_PackagePrivate.h */,
@@ -683,7 +681,7 @@
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 			shellPath = /bin/bash;
-			shellScript = "set -eu\nmkdir -p \"${PROJECT_DERIVED_FILE_DIR}/protos\"\nexport PATH=\"${PATH}:.\"\ncd \"${SRCROOT}\"/../src\n\nPROTOC=./protoc\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_custom_options.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_enormous_descriptor.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_embed_optimize_for.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_empty.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_import.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_import_lite.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_lite.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_mset.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_no_generic_services.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_optimize_for.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_import_public.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_import_public_lite.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_drop_unknown_fields.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_preserve_unknown_enum.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/map_lite_unittest.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/map_proto2_unittest.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/map_unittest.proto\n\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. --proto_path=\"${SRCROOT}\"/Tests \"${SRCROOT}\"/Tests/unittest_objc.proto\n\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=\"${SRCROOT}\"/Tests \"${SRCROOT}\"/Tests/unittest_cycle.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=\"${SRCROOT}\"/Tests \"${SRCROOT}\"/Tests/unittest_name_mangling.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=\"${SRCROOT}\"/Tests \"${SRCROOT}\"/Tests/unittest_runtime_proto2.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=\"${SRCROOT}\"/Tests \"${SRCROOT}\"/Tests/unittest_runtime_proto3.proto\n\nexport GPB_CLASSLIST_PATH=\"${PROJECT_DERIVED_FILE_DIR}/ClassList.txt\"\nexport GPB_OBJC_CLASS_WHITELIST_PATHS=\"${SRCROOT}/Tests/Filter1.txt;${SRCROOT}/Tests/Filter2.txt\"\n\nif [ -e ${GPB_CLASSLIST_PATH} ]; then\nrm ${GPB_CLASSLIST_PATH}\nfi\n\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=\"${SRCROOT}\"/Tests \"${SRCROOT}\"/Tests/unittest_filter.proto\n\n";
+			shellScript = "set -eu\nmkdir -p \"${PROJECT_DERIVED_FILE_DIR}/protos\"\nexport PATH=\"${PATH}:.\"\ncd \"${SRCROOT}\"/../src\n\nPROTOC=./protoc\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_custom_options.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_enormous_descriptor.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_embed_optimize_for.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_empty.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_import.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_import_lite.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_lite.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_mset.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_no_generic_services.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_optimize_for.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_import_public.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_import_public_lite.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_drop_unknown_fields.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/unittest_preserve_unknown_enum.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/map_lite_unittest.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/map_proto2_unittest.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. google/protobuf/map_unittest.proto\n\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=google/protobuf/ --proto_path=. --proto_path=\"${SRCROOT}\"/Tests \"${SRCROOT}\"/Tests/unittest_objc.proto\n\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=\"${SRCROOT}\"/Tests \"${SRCROOT}\"/Tests/unittest_cycle.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=\"${SRCROOT}\"/Tests \"${SRCROOT}\"/Tests/unittest_name_mangling.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=\"${SRCROOT}\"/Tests \"${SRCROOT}\"/Tests/unittest_runtime_proto2.proto\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=\"${SRCROOT}\"/Tests \"${SRCROOT}\"/Tests/unittest_runtime_proto3.proto\n\n# Use the filter\nexport GPB_OBJC_CLASS_WHITELIST_PATHS=\"${SRCROOT}/Tests/Filter1.txt;${SRCROOT}/Tests/Filter2.txt\"\n$PROTOC --objc_out=\"${PROJECT_DERIVED_FILE_DIR}/protos/google/protobuf\" --proto_path=\"${SRCROOT}\"/Tests \"${SRCROOT}\"/Tests/unittest_filter.proto\n\n";
 			showEnvVarsInLog = 0;
 		};
 		F4B62A791AF91F7500AFCEDC /* Script: Check Runtime Stamps */ = {
@@ -984,6 +982,7 @@
 				CLANG_WARN_SUSPICIOUS_IMPLICIT_CONVERSION = YES;
 				CLANG_WARN__DUPLICATE_METHOD_MATCH = YES;
 				"CODE_SIGN_IDENTITY[sdk=iphoneos*]" = "iPhone Developer";
+				ENABLE_NS_ASSERTIONS = NO;
 				GCC_C_LANGUAGE_STANDARD = c99;
 				GCC_TREAT_IMPLICIT_FUNCTION_DECLARATIONS_AS_ERRORS = YES;
 				GCC_TREAT_INCOMPATIBLE_POINTER_TYPE_WARNINGS_AS_ERRORS = YES;
diff --git a/objectivec/ProtocolBuffers_iOS.xcodeproj/xcshareddata/xcschemes/ProtocolBuffers.xcscheme b/objectivec/ProtocolBuffers_iOS.xcodeproj/xcshareddata/xcschemes/ProtocolBuffers.xcscheme
index a1b4cc45..c3c2c7d4 100644
--- a/objectivec/ProtocolBuffers_iOS.xcodeproj/xcshareddata/xcschemes/ProtocolBuffers.xcscheme
+++ b/objectivec/ProtocolBuffers_iOS.xcodeproj/xcshareddata/xcschemes/ProtocolBuffers.xcscheme
@@ -34,6 +34,20 @@
                ReferencedContainer = "container:ProtocolBuffers_iOS.xcodeproj">
             </BuildableReference>
          </BuildActionEntry>
+         <BuildActionEntry
+            buildForTesting = "YES"
+            buildForRunning = "NO"
+            buildForProfiling = "NO"
+            buildForArchiving = "NO"
+            buildForAnalyzing = "YES">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "8BBEA4A5147C727100C4ADB7"
+               BuildableName = "UnitTests.xctest"
+               BlueprintName = "UnitTests"
+               ReferencedContainer = "container:ProtocolBuffers_iOS.xcodeproj">
+            </BuildableReference>
+         </BuildActionEntry>
       </BuildActionEntries>
    </BuildAction>
    <TestAction
diff --git a/objectivec/README.md b/objectivec/README.md
new file mode 100644
index 00000000..186e45b2
--- /dev/null
+++ b/objectivec/README.md
@@ -0,0 +1,77 @@
+Protocol Buffers - Google's data interchange format
+===================================================
+
+[![Build Status](https://travis-ci.org/google/protobuf.svg?branch=master)](https://travis-ci.org/google/protobuf)
+
+Copyright 2008 Google Inc.
+
+This directory contains the Objective C Protocol Buffers runtime library.
+
+Requirements
+------------
+
+The Objective C implemention requires:
+
+- Objective C 2.0 Runtime (32bit & 64bit iOS, 64bit OS X).
+- Xcode 6.3 (or later).
+- The library code does *not* use ARC (for performance reasons), but it all can
+  be called from ARC code.
+
+Installation
+------------
+
+The full distribution pulled from github includes the sources for both the
+compiler (protoc) and the runtime (this directory).  To build the compiler
+and run the runtime tests, you can use:
+
+     $ objectivec/DevTools/full_mac_build.sh
+
+This will generate the `src/protoc` binary.
+
+Usage
+-----
+
+There are two ways to include the Runtime sources in your project:
+
+Add `objectivec/\*.h` & `objectivec/GPBProtocolBuffers.m` to your project.
+
+*or*
+
+Add `objectivec/\*.h` & `objectivec/\*.m` except for
+`objectivec/GPBProtocolBuffers.m` to your project.
+
+
+If the target is using ARC, remember to turn off ARC (`-fno-objc-arc`) for the
+`.m` files.
+
+The files generated by `protoc` for the `*.proto` files (`\*.pbobjc.h' and
+`\*.pbobjc.m`) are then also added to the target.
+
+The Objective C classes/enums can be used from Swift code.
+
+Objective C Generator Options
+-----------------------------
+
+**objc_class_prefix=\<prefix\>** (no default)
+
+Since Objective C uses a global namespace for all of its classes, there can
+be collisions.  This option provides a prefix that will be added to the Enums
+and Objects (for messages) generated from the proto.  Convention is to base
+the prefix on the package the proto is in.
+
+Contributing
+------------
+
+Please make updates to the tests along with changes. If just changing the
+runtime, the Xcode projects can be used to build and run tests.  If change also
+require changes to the generated code, `objectivec/DevTools/full_mac_build.sh`
+can be used to easily rebuild and test changes. Passing `-h` to the script will
+show the addition options that could be useful.
+
+Documentation
+-------------
+
+The complete documentation for Protocol Buffers is available via the
+web at:
+
+    https://developers.google.com/protocol-buffers/
diff --git a/objectivec/Tests/GPBArrayTests.m b/objectivec/Tests/GPBArrayTests.m
index 37724c59..0fb15e40 100644
--- a/objectivec/Tests/GPBArrayTests.m
+++ b/objectivec/Tests/GPBArrayTests.m
@@ -29,14 +29,11 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #import <Foundation/Foundation.h>
-
 #import <XCTest/XCTest.h>
 
 #import "GPBArray.h"
 
-#ifndef GPBARRAYSIZE
-#define GPBARRAYSIZE(a) ((sizeof(a) / sizeof((a[0]))))
-#endif  // GPBARRAYSIZE
+#import "GPBTestUtilities.h"
 
 // To let the testing macros work, add some extra methods to simplify things.
 @interface GPBEnumArray (TestingTweak)
@@ -233,6 +230,8 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
 //%  // Should be new object but equal.
 //%  XCTAssertNotEqual(array, array2);
 //%  XCTAssertEqualObjects(array, array2);
+//%  [array2 release];
+//%  [array release];
 //%}
 //%
 //%- (void)testArrayFromArray {
@@ -248,6 +247,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
 //%  // Should be new pointer, but equal objects.
 //%  XCTAssertNotEqual(array, array2);
 //%  XCTAssertEqualObjects(array, array2);
+//%  [array release];
 //%}
 //%
 //%- (void)testAdds {
@@ -275,6 +275,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
 //%  XCTAssertEqual([array valueAtIndex:2], VAL3);
 //%  XCTAssertEqual([array valueAtIndex:3], VAL4);
 //%  XCTAssertEqual([array valueAtIndex:4], VAL1);
+//%  [array2 release];
 //%}
 //%
 //%- (void)testInsert {
@@ -307,6 +308,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
 //%  XCTAssertEqual([array valueAtIndex:3], VAL2);
 //%  XCTAssertEqual([array valueAtIndex:4], VAL3);
 //%  XCTAssertEqual([array valueAtIndex:5], VAL4);
+//%  [array release];
 //%}
 //%
 //%- (void)testRemove {
@@ -343,6 +345,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
 //%  XCTAssertEqual(array.count, 0U);
 //%  XCTAssertThrowsSpecificNamed([array removeValueAtIndex:0],
 //%                               NSException, NSRangeException);
+//%  [array release];
 //%}
 //%
 //%- (void)testInplaceMutation {
@@ -381,6 +384,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
 //%                               NSException, NSRangeException);
 //%  XCTAssertThrowsSpecificNamed([array exchangeValueAtIndex:1 withValueAtIndex:4],
 //%                               NSException, NSRangeException);
+//%  [array release];
 //%}
 //%
 //%- (void)testInternalResizing {
@@ -405,6 +409,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
 //%  XCTAssertEqual(array.count, 404U);
 //%  [array removeAll];
 //%  XCTAssertEqual(array.count, 0U);
+//%  [array release];
 //%}
 //%
 //%@end
@@ -558,6 +563,8 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   // Should be new object but equal.
   XCTAssertNotEqual(array, array2);
   XCTAssertEqualObjects(array, array2);
+  [array2 release];
+  [array release];
 }
 
 - (void)testArrayFromArray {
@@ -573,6 +580,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   // Should be new pointer, but equal objects.
   XCTAssertNotEqual(array, array2);
   XCTAssertEqualObjects(array, array2);
+  [array release];
 }
 
 - (void)testAdds {
@@ -600,6 +608,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual([array valueAtIndex:2], 3);
   XCTAssertEqual([array valueAtIndex:3], 4);
   XCTAssertEqual([array valueAtIndex:4], 1);
+  [array2 release];
 }
 
 - (void)testInsert {
@@ -632,6 +641,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual([array valueAtIndex:3], 2);
   XCTAssertEqual([array valueAtIndex:4], 3);
   XCTAssertEqual([array valueAtIndex:5], 4);
+  [array release];
 }
 
 - (void)testRemove {
@@ -668,6 +678,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual(array.count, 0U);
   XCTAssertThrowsSpecificNamed([array removeValueAtIndex:0],
                                NSException, NSRangeException);
+  [array release];
 }
 
 - (void)testInplaceMutation {
@@ -706,6 +717,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
                                NSException, NSRangeException);
   XCTAssertThrowsSpecificNamed([array exchangeValueAtIndex:1 withValueAtIndex:4],
                                NSException, NSRangeException);
+  [array release];
 }
 
 - (void)testInternalResizing {
@@ -730,6 +742,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual(array.count, 404U);
   [array removeAll];
   XCTAssertEqual(array.count, 0U);
+  [array release];
 }
 
 @end
@@ -883,6 +896,8 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   // Should be new object but equal.
   XCTAssertNotEqual(array, array2);
   XCTAssertEqualObjects(array, array2);
+  [array2 release];
+  [array release];
 }
 
 - (void)testArrayFromArray {
@@ -898,6 +913,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   // Should be new pointer, but equal objects.
   XCTAssertNotEqual(array, array2);
   XCTAssertEqualObjects(array, array2);
+  [array release];
 }
 
 - (void)testAdds {
@@ -925,6 +941,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual([array valueAtIndex:2], 13U);
   XCTAssertEqual([array valueAtIndex:3], 14U);
   XCTAssertEqual([array valueAtIndex:4], 11U);
+  [array2 release];
 }
 
 - (void)testInsert {
@@ -957,6 +974,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual([array valueAtIndex:3], 12U);
   XCTAssertEqual([array valueAtIndex:4], 13U);
   XCTAssertEqual([array valueAtIndex:5], 14U);
+  [array release];
 }
 
 - (void)testRemove {
@@ -993,6 +1011,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual(array.count, 0U);
   XCTAssertThrowsSpecificNamed([array removeValueAtIndex:0],
                                NSException, NSRangeException);
+  [array release];
 }
 
 - (void)testInplaceMutation {
@@ -1031,6 +1050,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
                                NSException, NSRangeException);
   XCTAssertThrowsSpecificNamed([array exchangeValueAtIndex:1 withValueAtIndex:4],
                                NSException, NSRangeException);
+  [array release];
 }
 
 - (void)testInternalResizing {
@@ -1055,6 +1075,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual(array.count, 404U);
   [array removeAll];
   XCTAssertEqual(array.count, 0U);
+  [array release];
 }
 
 @end
@@ -1208,6 +1229,8 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   // Should be new object but equal.
   XCTAssertNotEqual(array, array2);
   XCTAssertEqualObjects(array, array2);
+  [array2 release];
+  [array release];
 }
 
 - (void)testArrayFromArray {
@@ -1223,6 +1246,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   // Should be new pointer, but equal objects.
   XCTAssertNotEqual(array, array2);
   XCTAssertEqualObjects(array, array2);
+  [array release];
 }
 
 - (void)testAdds {
@@ -1250,6 +1274,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual([array valueAtIndex:2], 33LL);
   XCTAssertEqual([array valueAtIndex:3], 34LL);
   XCTAssertEqual([array valueAtIndex:4], 31LL);
+  [array2 release];
 }
 
 - (void)testInsert {
@@ -1282,6 +1307,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual([array valueAtIndex:3], 32LL);
   XCTAssertEqual([array valueAtIndex:4], 33LL);
   XCTAssertEqual([array valueAtIndex:5], 34LL);
+  [array release];
 }
 
 - (void)testRemove {
@@ -1318,6 +1344,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual(array.count, 0U);
   XCTAssertThrowsSpecificNamed([array removeValueAtIndex:0],
                                NSException, NSRangeException);
+  [array release];
 }
 
 - (void)testInplaceMutation {
@@ -1356,6 +1383,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
                                NSException, NSRangeException);
   XCTAssertThrowsSpecificNamed([array exchangeValueAtIndex:1 withValueAtIndex:4],
                                NSException, NSRangeException);
+  [array release];
 }
 
 - (void)testInternalResizing {
@@ -1380,6 +1408,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual(array.count, 404U);
   [array removeAll];
   XCTAssertEqual(array.count, 0U);
+  [array release];
 }
 
 @end
@@ -1533,6 +1562,8 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   // Should be new object but equal.
   XCTAssertNotEqual(array, array2);
   XCTAssertEqualObjects(array, array2);
+  [array2 release];
+  [array release];
 }
 
 - (void)testArrayFromArray {
@@ -1548,6 +1579,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   // Should be new pointer, but equal objects.
   XCTAssertNotEqual(array, array2);
   XCTAssertEqualObjects(array, array2);
+  [array release];
 }
 
 - (void)testAdds {
@@ -1575,6 +1607,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual([array valueAtIndex:2], 43ULL);
   XCTAssertEqual([array valueAtIndex:3], 44ULL);
   XCTAssertEqual([array valueAtIndex:4], 41ULL);
+  [array2 release];
 }
 
 - (void)testInsert {
@@ -1607,6 +1640,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual([array valueAtIndex:3], 42ULL);
   XCTAssertEqual([array valueAtIndex:4], 43ULL);
   XCTAssertEqual([array valueAtIndex:5], 44ULL);
+  [array release];
 }
 
 - (void)testRemove {
@@ -1643,6 +1677,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual(array.count, 0U);
   XCTAssertThrowsSpecificNamed([array removeValueAtIndex:0],
                                NSException, NSRangeException);
+  [array release];
 }
 
 - (void)testInplaceMutation {
@@ -1681,6 +1716,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
                                NSException, NSRangeException);
   XCTAssertThrowsSpecificNamed([array exchangeValueAtIndex:1 withValueAtIndex:4],
                                NSException, NSRangeException);
+  [array release];
 }
 
 - (void)testInternalResizing {
@@ -1705,6 +1741,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual(array.count, 404U);
   [array removeAll];
   XCTAssertEqual(array.count, 0U);
+  [array release];
 }
 
 @end
@@ -1858,6 +1895,8 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   // Should be new object but equal.
   XCTAssertNotEqual(array, array2);
   XCTAssertEqualObjects(array, array2);
+  [array2 release];
+  [array release];
 }
 
 - (void)testArrayFromArray {
@@ -1873,6 +1912,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   // Should be new pointer, but equal objects.
   XCTAssertNotEqual(array, array2);
   XCTAssertEqualObjects(array, array2);
+  [array release];
 }
 
 - (void)testAdds {
@@ -1900,6 +1940,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual([array valueAtIndex:2], 53.f);
   XCTAssertEqual([array valueAtIndex:3], 54.f);
   XCTAssertEqual([array valueAtIndex:4], 51.f);
+  [array2 release];
 }
 
 - (void)testInsert {
@@ -1932,6 +1973,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual([array valueAtIndex:3], 52.f);
   XCTAssertEqual([array valueAtIndex:4], 53.f);
   XCTAssertEqual([array valueAtIndex:5], 54.f);
+  [array release];
 }
 
 - (void)testRemove {
@@ -1968,6 +2010,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual(array.count, 0U);
   XCTAssertThrowsSpecificNamed([array removeValueAtIndex:0],
                                NSException, NSRangeException);
+  [array release];
 }
 
 - (void)testInplaceMutation {
@@ -2006,6 +2049,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
                                NSException, NSRangeException);
   XCTAssertThrowsSpecificNamed([array exchangeValueAtIndex:1 withValueAtIndex:4],
                                NSException, NSRangeException);
+  [array release];
 }
 
 - (void)testInternalResizing {
@@ -2030,6 +2074,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual(array.count, 404U);
   [array removeAll];
   XCTAssertEqual(array.count, 0U);
+  [array release];
 }
 
 @end
@@ -2183,6 +2228,8 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   // Should be new object but equal.
   XCTAssertNotEqual(array, array2);
   XCTAssertEqualObjects(array, array2);
+  [array2 release];
+  [array release];
 }
 
 - (void)testArrayFromArray {
@@ -2198,6 +2245,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   // Should be new pointer, but equal objects.
   XCTAssertNotEqual(array, array2);
   XCTAssertEqualObjects(array, array2);
+  [array release];
 }
 
 - (void)testAdds {
@@ -2225,6 +2273,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual([array valueAtIndex:2], 63.);
   XCTAssertEqual([array valueAtIndex:3], 64.);
   XCTAssertEqual([array valueAtIndex:4], 61.);
+  [array2 release];
 }
 
 - (void)testInsert {
@@ -2257,6 +2306,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual([array valueAtIndex:3], 62.);
   XCTAssertEqual([array valueAtIndex:4], 63.);
   XCTAssertEqual([array valueAtIndex:5], 64.);
+  [array release];
 }
 
 - (void)testRemove {
@@ -2293,6 +2343,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual(array.count, 0U);
   XCTAssertThrowsSpecificNamed([array removeValueAtIndex:0],
                                NSException, NSRangeException);
+  [array release];
 }
 
 - (void)testInplaceMutation {
@@ -2331,6 +2382,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
                                NSException, NSRangeException);
   XCTAssertThrowsSpecificNamed([array exchangeValueAtIndex:1 withValueAtIndex:4],
                                NSException, NSRangeException);
+  [array release];
 }
 
 - (void)testInternalResizing {
@@ -2355,6 +2407,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual(array.count, 404U);
   [array removeAll];
   XCTAssertEqual(array.count, 0U);
+  [array release];
 }
 
 @end
@@ -2508,6 +2561,8 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   // Should be new object but equal.
   XCTAssertNotEqual(array, array2);
   XCTAssertEqualObjects(array, array2);
+  [array2 release];
+  [array release];
 }
 
 - (void)testArrayFromArray {
@@ -2523,6 +2578,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   // Should be new pointer, but equal objects.
   XCTAssertNotEqual(array, array2);
   XCTAssertEqualObjects(array, array2);
+  [array release];
 }
 
 - (void)testAdds {
@@ -2550,6 +2606,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual([array valueAtIndex:2], FALSE);
   XCTAssertEqual([array valueAtIndex:3], FALSE);
   XCTAssertEqual([array valueAtIndex:4], TRUE);
+  [array2 release];
 }
 
 - (void)testInsert {
@@ -2582,6 +2639,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual([array valueAtIndex:3], TRUE);
   XCTAssertEqual([array valueAtIndex:4], FALSE);
   XCTAssertEqual([array valueAtIndex:5], FALSE);
+  [array release];
 }
 
 - (void)testRemove {
@@ -2618,6 +2676,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual(array.count, 0U);
   XCTAssertThrowsSpecificNamed([array removeValueAtIndex:0],
                                NSException, NSRangeException);
+  [array release];
 }
 
 - (void)testInplaceMutation {
@@ -2656,6 +2715,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
                                NSException, NSRangeException);
   XCTAssertThrowsSpecificNamed([array exchangeValueAtIndex:1 withValueAtIndex:4],
                                NSException, NSRangeException);
+  [array release];
 }
 
 - (void)testInternalResizing {
@@ -2680,6 +2740,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual(array.count, 404U);
   [array removeAll];
   XCTAssertEqual(array.count, 0U);
+  [array release];
 }
 
 @end
@@ -2833,6 +2894,8 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   // Should be new object but equal.
   XCTAssertNotEqual(array, array2);
   XCTAssertEqualObjects(array, array2);
+  [array2 release];
+  [array release];
 }
 
 - (void)testArrayFromArray {
@@ -2848,6 +2911,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   // Should be new pointer, but equal objects.
   XCTAssertNotEqual(array, array2);
   XCTAssertEqualObjects(array, array2);
+  [array release];
 }
 
 - (void)testAdds {
@@ -2875,6 +2939,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual([array valueAtIndex:2], 73);
   XCTAssertEqual([array valueAtIndex:3], 74);
   XCTAssertEqual([array valueAtIndex:4], 71);
+  [array2 release];
 }
 
 - (void)testInsert {
@@ -2907,6 +2972,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual([array valueAtIndex:3], 72);
   XCTAssertEqual([array valueAtIndex:4], 73);
   XCTAssertEqual([array valueAtIndex:5], 74);
+  [array release];
 }
 
 - (void)testRemove {
@@ -2943,6 +3009,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual(array.count, 0U);
   XCTAssertThrowsSpecificNamed([array removeValueAtIndex:0],
                                NSException, NSRangeException);
+  [array release];
 }
 
 - (void)testInplaceMutation {
@@ -2981,6 +3048,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
                                NSException, NSRangeException);
   XCTAssertThrowsSpecificNamed([array exchangeValueAtIndex:1 withValueAtIndex:4],
                                NSException, NSRangeException);
+  [array release];
 }
 
 - (void)testInternalResizing {
@@ -3005,6 +3073,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual(array.count, 404U);
   [array removeAll];
   XCTAssertEqual(array.count, 0U);
+  [array release];
 }
 
 @end
@@ -3165,6 +3234,8 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual([array2 rawValueAtIndex:1], 72);
   XCTAssertEqual([array2 rawValueAtIndex:2], 1000);
   XCTAssertEqual([array2 valueAtIndex:2], kGPBUnrecognizedEnumeratorValue);
+  [array2 release];
+  [array release];
 }
 
 - (void)testArrayFromArray {
@@ -3182,6 +3253,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertNotEqual(array, array2);
   XCTAssertEqualObjects(array, array2);
   XCTAssertEqual(array.validationFunc, array2.validationFunc);
+  [array release];
 }
 
 - (void)testUnknownAdds {
@@ -3197,7 +3269,6 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertThrowsSpecificNamed([array addValues:kValues1 count:GPBARRAYSIZE(kValues1)],
                                NSException, NSInvalidArgumentException);
   XCTAssertEqual(array.count, 0U);
-
   [array release];
 }
 
@@ -3229,7 +3300,6 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual([array valueAtIndex:2], kGPBUnrecognizedEnumeratorValue);
   XCTAssertEqual([array rawValueAtIndex:3], 74);
   XCTAssertEqual([array rawValueAtIndex:4], 71);
-
   [array release];
 }
 
@@ -3256,6 +3326,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertThrowsSpecificNamed([array insertValue:374 atIndex:3],
                                NSException, NSInvalidArgumentException);
   XCTAssertEqual(array.count, 3U);
+  [array release];
 }
 
 - (void)testRawInsert {
@@ -3292,7 +3363,6 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual([array rawValueAtIndex:4], 73);
   XCTAssertEqual([array rawValueAtIndex:5], 374);
   XCTAssertEqual([array valueAtIndex:5], kGPBUnrecognizedEnumeratorValue);
-
   [array release];
 }
 
@@ -3313,6 +3383,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual([array valueAtIndex:1], 72);
   XCTAssertEqual([array valueAtIndex:2], 73);
   XCTAssertEqual([array valueAtIndex:3], 74);
+  [array release];
 }
 
 
@@ -3336,6 +3407,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
 
   XCTAssertThrowsSpecificNamed([array replaceValueAtIndex:4 withRawValue:74],
                                NSException, NSRangeException);
+  [array release];
 }
 
 - (void)testRawInternalResizing {
@@ -3360,6 +3432,7 @@ static BOOL TestingEnum_IsValidValue2(int32_t value) {
   XCTAssertEqual(array.count, 404U);
   [array removeAll];
   XCTAssertEqual(array.count, 0U);
+  [array release];
 }
 
 @end
diff --git a/objectivec/Tests/GPBCodedInputStreamTests.m b/objectivec/Tests/GPBCodedInputStreamTests.m
index 0a709cbe..5f29d7c8 100644
--- a/objectivec/Tests/GPBCodedInputStreamTests.m
+++ b/objectivec/Tests/GPBCodedInputStreamTests.m
@@ -184,7 +184,7 @@
   XCTAssertEqual(message.serializedSize, (size_t)rawBytes.length);
 
   TestAllTypes* message2 =
-      [TestAllTypes parseFromData:rawBytes extensionRegistry:nil];
+      [TestAllTypes parseFromData:rawBytes extensionRegistry:nil error:NULL];
   [self assertAllFieldsSet:message2 repeatedCount:kGPBDefaultRepeatCount];
 }
 
@@ -227,8 +227,9 @@
   // reading.
   GPBCodedInputStream* stream =
       [GPBCodedInputStream streamWithData:message.data];
-  TestAllTypes* message2 =
-      [TestAllTypes parseFromCodedInputStream:stream extensionRegistry:nil];
+  TestAllTypes* message2 = [TestAllTypes parseFromCodedInputStream:stream
+                                                 extensionRegistry:nil
+                                                             error:NULL];
 
   XCTAssertEqualObjects(message.optionalBytes, message2.optionalBytes);
 
@@ -280,8 +281,9 @@
   NSData* data =
       [rawOutput propertyForKey:NSStreamDataWrittenToMemoryStreamKey];
   GPBCodedInputStream* input = [GPBCodedInputStream streamWithData:data];
-  TestAllTypes* message =
-      [TestAllTypes parseFromCodedInputStream:input extensionRegistry:nil];
+  TestAllTypes* message = [TestAllTypes parseFromCodedInputStream:input
+                                                extensionRegistry:nil
+                                                            error:NULL];
   // Make sure we can read string properties twice without crashing.
   XCTAssertEqual([message.defaultString length], (NSUInteger)0);
   XCTAssertEqualObjects(@"", message.defaultString);
diff --git a/objectivec/Tests/GPBConcurrencyTests.m b/objectivec/Tests/GPBConcurrencyTests.m
index 3749fc34..e500ad77 100644
--- a/objectivec/Tests/GPBConcurrencyTests.m
+++ b/objectivec/Tests/GPBConcurrencyTests.m
@@ -31,10 +31,16 @@
 #import "GPBTestUtilities.h"
 
 #import "google/protobuf/Unittest.pbobjc.h"
+#import "google/protobuf/UnittestObjc.pbobjc.h"
 
 static const int kNumThreads = 100;
 static const int kNumMessages = 100;
 
+// NOTE: Most of these tests don't "fail" in the sense that the XCTAsserts
+// trip.  Rather, the asserts simply exercise the apis, and if there is
+// a concurancy issue, the NSAsserts in the runtime code fire and/or the
+// code just crashes outright.
+
 @interface ConcurrencyTests : GPBTestCase
 @end
 
@@ -132,6 +138,48 @@ static const int kNumMessages = 100;
   }
 }
 
+- (void)readInt32Int32Map:(NSArray *)messages {
+  for (int i = 0; i < 10; i++) {
+    for (TestRecursiveMessageWithRepeatedField *message in messages) {
+      XCTAssertEqual([message.iToI count], (NSUInteger)0);
+    }
+  }
+}
+
+- (void)testConcurrentReadOfUnsetInt32Int32MapField {
+  NSArray *messages =
+      [self createMessagesWithType:[TestRecursiveMessageWithRepeatedField class]];
+  NSArray *threads =
+      [self createThreadsWithSelector:@selector(readInt32Int32Map:)
+                               object:messages];
+  [self startThreads:threads];
+  [self joinThreads:threads];
+  for (TestRecursiveMessageWithRepeatedField *message in messages) {
+    XCTAssertEqual([message.iToI count], (NSUInteger)0);
+  }
+}
+
+- (void)readStringStringMap:(NSArray *)messages {
+  for (int i = 0; i < 10; i++) {
+    for (TestRecursiveMessageWithRepeatedField *message in messages) {
+      XCTAssertEqual([message.strToStr count], (NSUInteger)0);
+    }
+  }
+}
+
+- (void)testConcurrentReadOfUnsetStringStringMapField {
+  NSArray *messages =
+      [self createMessagesWithType:[TestRecursiveMessageWithRepeatedField class]];
+  NSArray *threads =
+      [self createThreadsWithSelector:@selector(readStringStringMap:)
+                               object:messages];
+  [self startThreads:threads];
+  [self joinThreads:threads];
+  for (TestRecursiveMessageWithRepeatedField *message in messages) {
+    XCTAssertEqual([message.strToStr count], (NSUInteger)0);
+  }
+}
+
 - (void)readOptionalForeignMessageExtension:(NSArray *)messages {
   for (int i = 0; i < 10; i++) {
     for (TestAllExtensions *message in messages) {
diff --git a/objectivec/Tests/GPBDictionaryTests+Bool.m b/objectivec/Tests/GPBDictionaryTests+Bool.m
index bc4998be..43650f51 100644
--- a/objectivec/Tests/GPBDictionaryTests+Bool.m
+++ b/objectivec/Tests/GPBDictionaryTests+Bool.m
@@ -33,12 +33,9 @@
 
 #import "GPBDictionary.h"
 
+#import "GPBTestUtilities.h"
 #import "google/protobuf/UnittestRuntimeProto2.pbobjc.h"
 
-#ifndef GPBARRAYSIZE
-#define GPBARRAYSIZE(a) ((sizeof(a) / sizeof((a[0]))))
-#endif  // GPBARRAYSIZE
-
 // Pull in the macros (using an external file because expanding all tests
 // in a single file makes a file that is failing to work with within Xcode.
 //%PDDM-IMPORT-DEFINES GPBDictionaryTests.pddm
diff --git a/objectivec/Tests/GPBDictionaryTests+Int32.m b/objectivec/Tests/GPBDictionaryTests+Int32.m
index 5e25799c..1ee099ee 100644
--- a/objectivec/Tests/GPBDictionaryTests+Int32.m
+++ b/objectivec/Tests/GPBDictionaryTests+Int32.m
@@ -33,6 +33,7 @@
 
 #import "GPBDictionary.h"
 
+#import "GPBTestUtilities.h"
 #import "google/protobuf/UnittestRuntimeProto2.pbobjc.h"
 
 // Pull in the macros (using an external file because expanding all tests
@@ -42,10 +43,6 @@
 //%PDDM-EXPAND TEST_FOR_POD_KEY(Int32, int32_t, 11, 12, 13, 14)
 // This block of code is generated, do not edit it directly.
 
-#ifndef GPBARRAYSIZE
-#define GPBARRAYSIZE(a) ((sizeof(a) / sizeof((a[0]))))
-#endif  // GPBARRAYSIZE
-
 // To let the testing macros work, add some extra methods to simplify things.
 @interface GPBInt32EnumDictionary (TestingTweak)
 + (instancetype)dictionaryWithValue:(int32_t)value forKey:(int32_t)key;
diff --git a/objectivec/Tests/GPBDictionaryTests+Int64.m b/objectivec/Tests/GPBDictionaryTests+Int64.m
index 6e794d38..4a94e033 100644
--- a/objectivec/Tests/GPBDictionaryTests+Int64.m
+++ b/objectivec/Tests/GPBDictionaryTests+Int64.m
@@ -33,6 +33,7 @@
 
 #import "GPBDictionary.h"
 
+#import "GPBTestUtilities.h"
 #import "google/protobuf/UnittestRuntimeProto2.pbobjc.h"
 
 // Pull in the macros (using an external file because expanding all tests
@@ -42,10 +43,6 @@
 //%PDDM-EXPAND TEST_FOR_POD_KEY(Int64, int64_t, 21LL, 22LL, 23LL, 24LL)
 // This block of code is generated, do not edit it directly.
 
-#ifndef GPBARRAYSIZE
-#define GPBARRAYSIZE(a) ((sizeof(a) / sizeof((a[0]))))
-#endif  // GPBARRAYSIZE
-
 // To let the testing macros work, add some extra methods to simplify things.
 @interface GPBInt64EnumDictionary (TestingTweak)
 + (instancetype)dictionaryWithValue:(int32_t)value forKey:(int64_t)key;
diff --git a/objectivec/Tests/GPBDictionaryTests+String.m b/objectivec/Tests/GPBDictionaryTests+String.m
index 95bf2d06..09fbc608 100644
--- a/objectivec/Tests/GPBDictionaryTests+String.m
+++ b/objectivec/Tests/GPBDictionaryTests+String.m
@@ -33,6 +33,7 @@
 
 #import "GPBDictionary.h"
 
+#import "GPBTestUtilities.h"
 #import "google/protobuf/UnittestRuntimeProto2.pbobjc.h"
 
 // Pull in the macros (using an external file because expanding all tests
@@ -42,10 +43,6 @@
 //%PDDM-EXPAND TESTS_FOR_POD_VALUES(String, NSString, *, Objects, @"foo", @"bar", @"baz", @"mumble")
 // This block of code is generated, do not edit it directly.
 
-#ifndef GPBARRAYSIZE
-#define GPBARRAYSIZE(a) ((sizeof(a) / sizeof((a[0]))))
-#endif  // GPBARRAYSIZE
-
 // To let the testing macros work, add some extra methods to simplify things.
 @interface GPBStringEnumDictionary (TestingTweak)
 + (instancetype)dictionaryWithValue:(int32_t)value forKey:(NSString *)key;
diff --git a/objectivec/Tests/GPBDictionaryTests+UInt32.m b/objectivec/Tests/GPBDictionaryTests+UInt32.m
index a89ded3d..f8d280fa 100644
--- a/objectivec/Tests/GPBDictionaryTests+UInt32.m
+++ b/objectivec/Tests/GPBDictionaryTests+UInt32.m
@@ -33,6 +33,7 @@
 
 #import "GPBDictionary.h"
 
+#import "GPBTestUtilities.h"
 #import "google/protobuf/UnittestRuntimeProto2.pbobjc.h"
 
 // Pull in the macros (using an external file because expanding all tests
@@ -42,10 +43,6 @@
 //%PDDM-EXPAND TEST_FOR_POD_KEY(UInt32, uint32_t, 1U, 2U, 3U, 4U)
 // This block of code is generated, do not edit it directly.
 
-#ifndef GPBARRAYSIZE
-#define GPBARRAYSIZE(a) ((sizeof(a) / sizeof((a[0]))))
-#endif  // GPBARRAYSIZE
-
 // To let the testing macros work, add some extra methods to simplify things.
 @interface GPBUInt32EnumDictionary (TestingTweak)
 + (instancetype)dictionaryWithValue:(int32_t)value forKey:(uint32_t)key;
diff --git a/objectivec/Tests/GPBDictionaryTests+UInt64.m b/objectivec/Tests/GPBDictionaryTests+UInt64.m
index 355639c6..cebd6df2 100644
--- a/objectivec/Tests/GPBDictionaryTests+UInt64.m
+++ b/objectivec/Tests/GPBDictionaryTests+UInt64.m
@@ -33,6 +33,7 @@
 
 #import "GPBDictionary.h"
 
+#import "GPBTestUtilities.h"
 #import "google/protobuf/UnittestRuntimeProto2.pbobjc.h"
 
 // Pull in the macros (using an external file because expanding all tests
@@ -42,10 +43,6 @@
 //%PDDM-EXPAND TEST_FOR_POD_KEY(UInt64, uint64_t, 31ULL, 32ULL, 33ULL, 34ULL)
 // This block of code is generated, do not edit it directly.
 
-#ifndef GPBARRAYSIZE
-#define GPBARRAYSIZE(a) ((sizeof(a) / sizeof((a[0]))))
-#endif  // GPBARRAYSIZE
-
 // To let the testing macros work, add some extra methods to simplify things.
 @interface GPBUInt64EnumDictionary (TestingTweak)
 + (instancetype)dictionaryWithValue:(int32_t)value forKey:(uint64_t)key;
diff --git a/objectivec/Tests/GPBDictionaryTests.pddm b/objectivec/Tests/GPBDictionaryTests.pddm
index 39793e03..ee26fac8 100644
--- a/objectivec/Tests/GPBDictionaryTests.pddm
+++ b/objectivec/Tests/GPBDictionaryTests.pddm
@@ -720,10 +720,6 @@
 //
 
 //%PDDM-DEFINE TEST_HELPERS(KEY_NAME, KEY_TYPE, KisP)
-//%#ifndef GPBARRAYSIZE
-//%#define GPBARRAYSIZE(a) ((sizeof(a) / sizeof((a[0]))))
-//%#endif  // GPBARRAYSIZE
-//%
 //%// To let the testing macros work, add some extra methods to simplify things.
 //%@interface GPB##KEY_NAME##EnumDictionary (TestingTweak)
 //%+ (instancetype)dictionaryWithValue:(int32_t)value forKey:(KEY_TYPE##KisP$S##KisP)key;
diff --git a/objectivec/Tests/GPBMessageTests+Merge.m b/objectivec/Tests/GPBMessageTests+Merge.m
index 599ad055..3b6fdbd4 100644
--- a/objectivec/Tests/GPBMessageTests+Merge.m
+++ b/objectivec/Tests/GPBMessageTests+Merge.m
@@ -35,6 +35,7 @@
 #import "GPBMessage.h"
 
 #import "google/protobuf/MapUnittest.pbobjc.h"
+#import "google/protobuf/Unittest.pbobjc.h"
 #import "google/protobuf/UnittestPreserveUnknownEnum.pbobjc.h"
 #import "google/protobuf/UnittestRuntimeProto2.pbobjc.h"
 #import "google/protobuf/UnittestRuntimeProto3.pbobjc.h"
@@ -431,7 +432,7 @@
   XCTAssertNotNil(dst.oneofGroup);
   XCTAssertNotEqual(dst.oneofGroup, mergedGroup);  // Pointer comparision.
 
-  // Back to something else ot make sure message clears out ok.
+  // Back to something else to make sure message clears out ok.
 
   src.oneofInt32 = 10;
   [dst mergeFrom:src];
@@ -640,7 +641,7 @@
   XCTAssertEqualObjects(mergedSubMessage, subMessage);
   XCTAssertEqualObjects(dst.oneofBytes, oneofBytesDefault);
 
-  // Back to something else ot make sure message clears out ok.
+  // Back to something else to make sure message clears out ok.
 
   src.oneofInt32 = 10;
   [dst mergeFrom:src];
diff --git a/objectivec/Tests/GPBMessageTests+Runtime.m b/objectivec/Tests/GPBMessageTests+Runtime.m
index 6ad29ca5..4621f90f 100644
--- a/objectivec/Tests/GPBMessageTests+Runtime.m
+++ b/objectivec/Tests/GPBMessageTests+Runtime.m
@@ -35,6 +35,7 @@
 #import "GPBMessage.h"
 
 #import "google/protobuf/MapUnittest.pbobjc.h"
+#import "google/protobuf/Unittest.pbobjc.h"
 #import "google/protobuf/UnittestRuntimeProto2.pbobjc.h"
 #import "google/protobuf/UnittestRuntimeProto3.pbobjc.h"
 
@@ -772,6 +773,8 @@
   XCTAssertThrowsSpecificNamed(msg.oneofEnum = 666, NSException,
                                NSInvalidArgumentException);
   XCTAssertEqual(msg.oneofEnum, Message2_Enum_Bar);
+
+  [msg release];
 }
 
 - (void)testAccessingProto3UnknownEnumValues {
@@ -1261,7 +1264,7 @@
     Message2_O_OneOfCase_OneofEnum,
   };
 
-  for (size_t i = 0; i < (sizeof(values) / sizeof((values[0]))); ++i) {
+  for (size_t i = 0; i < GPBARRAYSIZE(values); ++i) {
     switch (values[i]) {
       case Message2_O_OneOfCase_OneofInt32:
         msg.oneofInt32 = 1;
@@ -1318,7 +1321,7 @@
         msg.oneofEnum = Message2_Enum_Bar;
         break;
       default:
-        XCTFail(@"shouldn't happen, loop: %zd", i);
+        XCTFail(@"shouldn't happen, loop: %zd, value: %d", i, values[i]);
         break;
     }
 
@@ -1770,7 +1773,7 @@
     Message3_O_OneOfCase_OneofEnum,
   };
 
-  for (size_t i = 0; i < (sizeof(values) / sizeof((values[0]))); ++i) {
+  for (size_t i = 0; i < GPBARRAYSIZE(values); ++i) {
     switch (values[i]) {
       case Message3_O_OneOfCase_OneofInt32:
         msg.oneofInt32 = 1;
@@ -1824,7 +1827,7 @@
         msg.oneofEnum = Message3_Enum_Baz;
         break;
       default:
-        XCTFail(@"shouldn't happen, loop: %zd", i);
+        XCTFail(@"shouldn't happen, loop: %zd, value: %d", i, values[i]);
         break;
     }
 
diff --git a/objectivec/Tests/GPBMessageTests+Serialization.m b/objectivec/Tests/GPBMessageTests+Serialization.m
index ddc2ae19..8867f56d 100644
--- a/objectivec/Tests/GPBMessageTests+Serialization.m
+++ b/objectivec/Tests/GPBMessageTests+Serialization.m
@@ -41,10 +41,6 @@
 #import "google/protobuf/UnittestRuntimeProto2.pbobjc.h"
 #import "google/protobuf/UnittestRuntimeProto3.pbobjc.h"
 
-#ifndef GPBARRAYSIZE
-#define GPBARRAYSIZE(a) ((sizeof(a) / sizeof((a[0]))))
-#endif  // GPBARRAYSIZE
-
 static NSData *DataFromCStr(const char *str) {
   return [NSData dataWithBytes:str length:strlen(str)];
 }
@@ -124,7 +120,8 @@ static NSData *DataFromCStr(const char *str) {
   fooWithExtras.enumValue = DropUnknownsFooWithExtraFields_NestedEnum_Baz;
   fooWithExtras.extraInt32Value = 2;
 
-  DropUnknownsFoo *foo = [DropUnknownsFoo parseFromData:[fooWithExtras data]];
+  DropUnknownsFoo *foo =
+      [DropUnknownsFoo parseFromData:[fooWithExtras data] error:NULL];
 
   XCTAssertEqual(foo.int32Value, 1);
   XCTAssertEqual(foo.enumValue, DropUnknownsFoo_NestedEnum_Baz);
@@ -132,7 +129,8 @@ static NSData *DataFromCStr(const char *str) {
   XCTAssertEqual([foo.unknownFields countOfFields], 0U);
 
   [fooWithExtras release];
-  fooWithExtras = [DropUnknownsFooWithExtraFields parseFromData:[foo data]];
+  fooWithExtras =
+      [DropUnknownsFooWithExtraFields parseFromData:[foo data] error:NULL];
   XCTAssertEqual(fooWithExtras.int32Value, 1);
   XCTAssertEqual(fooWithExtras.enumValue,
                  DropUnknownsFooWithExtraFields_NestedEnum_Baz);
@@ -153,7 +151,7 @@ static NSData *DataFromCStr(const char *str) {
                                        rawValue:Message3_Enum_Extra3];
   orig.oneofEnum = Message3_Enum_Extra3;
 
-  Message2 *msg = [[Message2 alloc] initWithData:[orig data]];
+  Message2 *msg = [[Message2 alloc] initWithData:[orig data] error:NULL];
 
   // None of the fields should be set.
 
@@ -214,7 +212,7 @@ static NSData *DataFromCStr(const char *str) {
   // Everything should be there via raw values.
 
   UnknownEnumsMyMessage *msg =
-      [UnknownEnumsMyMessage parseFromData:[orig data]];
+      [UnknownEnumsMyMessage parseFromData:[orig data] error:NULL];
 
   XCTAssertEqual(msg.e, UnknownEnumsMyEnum_GPBUnrecognizedEnumeratorValue);
   XCTAssertEqual(UnknownEnumsMyMessage_E_RawValue(msg),
@@ -236,7 +234,7 @@ static NSData *DataFromCStr(const char *str) {
 
   // Everything should go out and come back.
 
-  orig = [UnknownEnumsMyMessagePlusExtra parseFromData:[msg data]];
+  orig = [UnknownEnumsMyMessagePlusExtra parseFromData:[msg data] error:NULL];
 
   XCTAssertEqual(orig.e, UnknownEnumsMyEnumPlusExtra_EExtra);
   XCTAssertEqual(orig.repeatedEArray.count, 1U);
@@ -255,7 +253,7 @@ static NSData *DataFromCStr(const char *str) {
 //%    MESSAGE *orig = [[MESSAGE alloc] init];
 //%    orig.oneof##FIELD = VALUE;
 //%    XCTAssertEqual(orig.oOneOfCase, MESSAGE##_O_OneOfCase_Oneof##FIELD);
-//%    MESSAGE *msg = [MESSAGE parseFromData:[orig data]];
+//%    MESSAGE *msg = [MESSAGE parseFromData:[orig data] error:NULL];
 //%    XCTAssertEqual(msg.oOneOfCase, MESSAGE##_O_OneOfCase_Oneof##FIELD);
 //%    XCTAssertEqual##EQ_SUFFIX(msg.oneof##FIELD, VALUE);
 //%    [orig release];
@@ -323,7 +321,7 @@ static NSData *DataFromCStr(const char *str) {
     Message2 *orig = [[Message2 alloc] init];
     orig.oneofInt32 = 1;
     XCTAssertEqual(orig.oOneOfCase, Message2_O_OneOfCase_OneofInt32);
-    Message2 *msg = [Message2 parseFromData:[orig data]];
+    Message2 *msg = [Message2 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message2_O_OneOfCase_OneofInt32);
     XCTAssertEqual(msg.oneofInt32, 1);
     [orig release];
@@ -333,7 +331,7 @@ static NSData *DataFromCStr(const char *str) {
     Message2 *orig = [[Message2 alloc] init];
     orig.oneofInt64 = 2;
     XCTAssertEqual(orig.oOneOfCase, Message2_O_OneOfCase_OneofInt64);
-    Message2 *msg = [Message2 parseFromData:[orig data]];
+    Message2 *msg = [Message2 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message2_O_OneOfCase_OneofInt64);
     XCTAssertEqual(msg.oneofInt64, 2);
     [orig release];
@@ -343,7 +341,7 @@ static NSData *DataFromCStr(const char *str) {
     Message2 *orig = [[Message2 alloc] init];
     orig.oneofUint32 = 3U;
     XCTAssertEqual(orig.oOneOfCase, Message2_O_OneOfCase_OneofUint32);
-    Message2 *msg = [Message2 parseFromData:[orig data]];
+    Message2 *msg = [Message2 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message2_O_OneOfCase_OneofUint32);
     XCTAssertEqual(msg.oneofUint32, 3U);
     [orig release];
@@ -353,7 +351,7 @@ static NSData *DataFromCStr(const char *str) {
     Message2 *orig = [[Message2 alloc] init];
     orig.oneofUint64 = 4U;
     XCTAssertEqual(orig.oOneOfCase, Message2_O_OneOfCase_OneofUint64);
-    Message2 *msg = [Message2 parseFromData:[orig data]];
+    Message2 *msg = [Message2 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message2_O_OneOfCase_OneofUint64);
     XCTAssertEqual(msg.oneofUint64, 4U);
     [orig release];
@@ -363,7 +361,7 @@ static NSData *DataFromCStr(const char *str) {
     Message2 *orig = [[Message2 alloc] init];
     orig.oneofSint32 = 5;
     XCTAssertEqual(orig.oOneOfCase, Message2_O_OneOfCase_OneofSint32);
-    Message2 *msg = [Message2 parseFromData:[orig data]];
+    Message2 *msg = [Message2 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message2_O_OneOfCase_OneofSint32);
     XCTAssertEqual(msg.oneofSint32, 5);
     [orig release];
@@ -373,7 +371,7 @@ static NSData *DataFromCStr(const char *str) {
     Message2 *orig = [[Message2 alloc] init];
     orig.oneofSint64 = 6;
     XCTAssertEqual(orig.oOneOfCase, Message2_O_OneOfCase_OneofSint64);
-    Message2 *msg = [Message2 parseFromData:[orig data]];
+    Message2 *msg = [Message2 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message2_O_OneOfCase_OneofSint64);
     XCTAssertEqual(msg.oneofSint64, 6);
     [orig release];
@@ -383,7 +381,7 @@ static NSData *DataFromCStr(const char *str) {
     Message2 *orig = [[Message2 alloc] init];
     orig.oneofFixed32 = 7U;
     XCTAssertEqual(orig.oOneOfCase, Message2_O_OneOfCase_OneofFixed32);
-    Message2 *msg = [Message2 parseFromData:[orig data]];
+    Message2 *msg = [Message2 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message2_O_OneOfCase_OneofFixed32);
     XCTAssertEqual(msg.oneofFixed32, 7U);
     [orig release];
@@ -393,7 +391,7 @@ static NSData *DataFromCStr(const char *str) {
     Message2 *orig = [[Message2 alloc] init];
     orig.oneofFixed64 = 8U;
     XCTAssertEqual(orig.oOneOfCase, Message2_O_OneOfCase_OneofFixed64);
-    Message2 *msg = [Message2 parseFromData:[orig data]];
+    Message2 *msg = [Message2 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message2_O_OneOfCase_OneofFixed64);
     XCTAssertEqual(msg.oneofFixed64, 8U);
     [orig release];
@@ -403,7 +401,7 @@ static NSData *DataFromCStr(const char *str) {
     Message2 *orig = [[Message2 alloc] init];
     orig.oneofSfixed32 = 9;
     XCTAssertEqual(orig.oOneOfCase, Message2_O_OneOfCase_OneofSfixed32);
-    Message2 *msg = [Message2 parseFromData:[orig data]];
+    Message2 *msg = [Message2 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message2_O_OneOfCase_OneofSfixed32);
     XCTAssertEqual(msg.oneofSfixed32, 9);
     [orig release];
@@ -413,7 +411,7 @@ static NSData *DataFromCStr(const char *str) {
     Message2 *orig = [[Message2 alloc] init];
     orig.oneofSfixed64 = 10;
     XCTAssertEqual(orig.oOneOfCase, Message2_O_OneOfCase_OneofSfixed64);
-    Message2 *msg = [Message2 parseFromData:[orig data]];
+    Message2 *msg = [Message2 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message2_O_OneOfCase_OneofSfixed64);
     XCTAssertEqual(msg.oneofSfixed64, 10);
     [orig release];
@@ -423,7 +421,7 @@ static NSData *DataFromCStr(const char *str) {
     Message2 *orig = [[Message2 alloc] init];
     orig.oneofFloat = 11.0f;
     XCTAssertEqual(orig.oOneOfCase, Message2_O_OneOfCase_OneofFloat);
-    Message2 *msg = [Message2 parseFromData:[orig data]];
+    Message2 *msg = [Message2 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message2_O_OneOfCase_OneofFloat);
     XCTAssertEqual(msg.oneofFloat, 11.0f);
     [orig release];
@@ -433,7 +431,7 @@ static NSData *DataFromCStr(const char *str) {
     Message2 *orig = [[Message2 alloc] init];
     orig.oneofDouble = 12.0;
     XCTAssertEqual(orig.oOneOfCase, Message2_O_OneOfCase_OneofDouble);
-    Message2 *msg = [Message2 parseFromData:[orig data]];
+    Message2 *msg = [Message2 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message2_O_OneOfCase_OneofDouble);
     XCTAssertEqual(msg.oneofDouble, 12.0);
     [orig release];
@@ -443,7 +441,7 @@ static NSData *DataFromCStr(const char *str) {
     Message2 *orig = [[Message2 alloc] init];
     orig.oneofBool = NO;
     XCTAssertEqual(orig.oOneOfCase, Message2_O_OneOfCase_OneofBool);
-    Message2 *msg = [Message2 parseFromData:[orig data]];
+    Message2 *msg = [Message2 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message2_O_OneOfCase_OneofBool);
     XCTAssertEqual(msg.oneofBool, NO);
     [orig release];
@@ -453,7 +451,7 @@ static NSData *DataFromCStr(const char *str) {
     Message2 *orig = [[Message2 alloc] init];
     orig.oneofString = @"foo";
     XCTAssertEqual(orig.oOneOfCase, Message2_O_OneOfCase_OneofString);
-    Message2 *msg = [Message2 parseFromData:[orig data]];
+    Message2 *msg = [Message2 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message2_O_OneOfCase_OneofString);
     XCTAssertEqualObjects(msg.oneofString, @"foo");
     [orig release];
@@ -463,7 +461,7 @@ static NSData *DataFromCStr(const char *str) {
     Message2 *orig = [[Message2 alloc] init];
     orig.oneofBytes = [@"bar" dataUsingEncoding:NSUTF8StringEncoding];
     XCTAssertEqual(orig.oOneOfCase, Message2_O_OneOfCase_OneofBytes);
-    Message2 *msg = [Message2 parseFromData:[orig data]];
+    Message2 *msg = [Message2 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message2_O_OneOfCase_OneofBytes);
     XCTAssertEqualObjects(msg.oneofBytes, [@"bar" dataUsingEncoding:NSUTF8StringEncoding]);
     [orig release];
@@ -473,7 +471,7 @@ static NSData *DataFromCStr(const char *str) {
     Message2 *orig = [[Message2 alloc] init];
     orig.oneofGroup = group;
     XCTAssertEqual(orig.oOneOfCase, Message2_O_OneOfCase_OneofGroup);
-    Message2 *msg = [Message2 parseFromData:[orig data]];
+    Message2 *msg = [Message2 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message2_O_OneOfCase_OneofGroup);
     XCTAssertEqualObjects(msg.oneofGroup, group);
     [orig release];
@@ -483,7 +481,7 @@ static NSData *DataFromCStr(const char *str) {
     Message2 *orig = [[Message2 alloc] init];
     orig.oneofMessage = subMessage;
     XCTAssertEqual(orig.oOneOfCase, Message2_O_OneOfCase_OneofMessage);
-    Message2 *msg = [Message2 parseFromData:[orig data]];
+    Message2 *msg = [Message2 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message2_O_OneOfCase_OneofMessage);
     XCTAssertEqualObjects(msg.oneofMessage, subMessage);
     [orig release];
@@ -493,7 +491,7 @@ static NSData *DataFromCStr(const char *str) {
     Message2 *orig = [[Message2 alloc] init];
     orig.oneofEnum = Message2_Enum_Bar;
     XCTAssertEqual(orig.oOneOfCase, Message2_O_OneOfCase_OneofEnum);
-    Message2 *msg = [Message2 parseFromData:[orig data]];
+    Message2 *msg = [Message2 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message2_O_OneOfCase_OneofEnum);
     XCTAssertEqual(msg.oneofEnum, Message2_Enum_Bar);
     [orig release];
@@ -516,7 +514,7 @@ static NSData *DataFromCStr(const char *str) {
     Message3 *orig = [[Message3 alloc] init];
     orig.oneofInt32 = 1;
     XCTAssertEqual(orig.oOneOfCase, Message3_O_OneOfCase_OneofInt32);
-    Message3 *msg = [Message3 parseFromData:[orig data]];
+    Message3 *msg = [Message3 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message3_O_OneOfCase_OneofInt32);
     XCTAssertEqual(msg.oneofInt32, 1);
     [orig release];
@@ -526,7 +524,7 @@ static NSData *DataFromCStr(const char *str) {
     Message3 *orig = [[Message3 alloc] init];
     orig.oneofInt64 = 2;
     XCTAssertEqual(orig.oOneOfCase, Message3_O_OneOfCase_OneofInt64);
-    Message3 *msg = [Message3 parseFromData:[orig data]];
+    Message3 *msg = [Message3 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message3_O_OneOfCase_OneofInt64);
     XCTAssertEqual(msg.oneofInt64, 2);
     [orig release];
@@ -536,7 +534,7 @@ static NSData *DataFromCStr(const char *str) {
     Message3 *orig = [[Message3 alloc] init];
     orig.oneofUint32 = 3U;
     XCTAssertEqual(orig.oOneOfCase, Message3_O_OneOfCase_OneofUint32);
-    Message3 *msg = [Message3 parseFromData:[orig data]];
+    Message3 *msg = [Message3 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message3_O_OneOfCase_OneofUint32);
     XCTAssertEqual(msg.oneofUint32, 3U);
     [orig release];
@@ -546,7 +544,7 @@ static NSData *DataFromCStr(const char *str) {
     Message3 *orig = [[Message3 alloc] init];
     orig.oneofUint64 = 4U;
     XCTAssertEqual(orig.oOneOfCase, Message3_O_OneOfCase_OneofUint64);
-    Message3 *msg = [Message3 parseFromData:[orig data]];
+    Message3 *msg = [Message3 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message3_O_OneOfCase_OneofUint64);
     XCTAssertEqual(msg.oneofUint64, 4U);
     [orig release];
@@ -556,7 +554,7 @@ static NSData *DataFromCStr(const char *str) {
     Message3 *orig = [[Message3 alloc] init];
     orig.oneofSint32 = 5;
     XCTAssertEqual(orig.oOneOfCase, Message3_O_OneOfCase_OneofSint32);
-    Message3 *msg = [Message3 parseFromData:[orig data]];
+    Message3 *msg = [Message3 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message3_O_OneOfCase_OneofSint32);
     XCTAssertEqual(msg.oneofSint32, 5);
     [orig release];
@@ -566,7 +564,7 @@ static NSData *DataFromCStr(const char *str) {
     Message3 *orig = [[Message3 alloc] init];
     orig.oneofSint64 = 6;
     XCTAssertEqual(orig.oOneOfCase, Message3_O_OneOfCase_OneofSint64);
-    Message3 *msg = [Message3 parseFromData:[orig data]];
+    Message3 *msg = [Message3 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message3_O_OneOfCase_OneofSint64);
     XCTAssertEqual(msg.oneofSint64, 6);
     [orig release];
@@ -576,7 +574,7 @@ static NSData *DataFromCStr(const char *str) {
     Message3 *orig = [[Message3 alloc] init];
     orig.oneofFixed32 = 7U;
     XCTAssertEqual(orig.oOneOfCase, Message3_O_OneOfCase_OneofFixed32);
-    Message3 *msg = [Message3 parseFromData:[orig data]];
+    Message3 *msg = [Message3 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message3_O_OneOfCase_OneofFixed32);
     XCTAssertEqual(msg.oneofFixed32, 7U);
     [orig release];
@@ -586,7 +584,7 @@ static NSData *DataFromCStr(const char *str) {
     Message3 *orig = [[Message3 alloc] init];
     orig.oneofFixed64 = 8U;
     XCTAssertEqual(orig.oOneOfCase, Message3_O_OneOfCase_OneofFixed64);
-    Message3 *msg = [Message3 parseFromData:[orig data]];
+    Message3 *msg = [Message3 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message3_O_OneOfCase_OneofFixed64);
     XCTAssertEqual(msg.oneofFixed64, 8U);
     [orig release];
@@ -596,7 +594,7 @@ static NSData *DataFromCStr(const char *str) {
     Message3 *orig = [[Message3 alloc] init];
     orig.oneofSfixed32 = 9;
     XCTAssertEqual(orig.oOneOfCase, Message3_O_OneOfCase_OneofSfixed32);
-    Message3 *msg = [Message3 parseFromData:[orig data]];
+    Message3 *msg = [Message3 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message3_O_OneOfCase_OneofSfixed32);
     XCTAssertEqual(msg.oneofSfixed32, 9);
     [orig release];
@@ -606,7 +604,7 @@ static NSData *DataFromCStr(const char *str) {
     Message3 *orig = [[Message3 alloc] init];
     orig.oneofSfixed64 = 10;
     XCTAssertEqual(orig.oOneOfCase, Message3_O_OneOfCase_OneofSfixed64);
-    Message3 *msg = [Message3 parseFromData:[orig data]];
+    Message3 *msg = [Message3 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message3_O_OneOfCase_OneofSfixed64);
     XCTAssertEqual(msg.oneofSfixed64, 10);
     [orig release];
@@ -616,7 +614,7 @@ static NSData *DataFromCStr(const char *str) {
     Message3 *orig = [[Message3 alloc] init];
     orig.oneofFloat = 11.0f;
     XCTAssertEqual(orig.oOneOfCase, Message3_O_OneOfCase_OneofFloat);
-    Message3 *msg = [Message3 parseFromData:[orig data]];
+    Message3 *msg = [Message3 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message3_O_OneOfCase_OneofFloat);
     XCTAssertEqual(msg.oneofFloat, 11.0f);
     [orig release];
@@ -626,7 +624,7 @@ static NSData *DataFromCStr(const char *str) {
     Message3 *orig = [[Message3 alloc] init];
     orig.oneofDouble = 12.0;
     XCTAssertEqual(orig.oOneOfCase, Message3_O_OneOfCase_OneofDouble);
-    Message3 *msg = [Message3 parseFromData:[orig data]];
+    Message3 *msg = [Message3 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message3_O_OneOfCase_OneofDouble);
     XCTAssertEqual(msg.oneofDouble, 12.0);
     [orig release];
@@ -636,7 +634,7 @@ static NSData *DataFromCStr(const char *str) {
     Message3 *orig = [[Message3 alloc] init];
     orig.oneofBool = YES;
     XCTAssertEqual(orig.oOneOfCase, Message3_O_OneOfCase_OneofBool);
-    Message3 *msg = [Message3 parseFromData:[orig data]];
+    Message3 *msg = [Message3 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message3_O_OneOfCase_OneofBool);
     XCTAssertEqual(msg.oneofBool, YES);
     [orig release];
@@ -646,7 +644,7 @@ static NSData *DataFromCStr(const char *str) {
     Message3 *orig = [[Message3 alloc] init];
     orig.oneofString = @"foo";
     XCTAssertEqual(orig.oOneOfCase, Message3_O_OneOfCase_OneofString);
-    Message3 *msg = [Message3 parseFromData:[orig data]];
+    Message3 *msg = [Message3 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message3_O_OneOfCase_OneofString);
     XCTAssertEqualObjects(msg.oneofString, @"foo");
     [orig release];
@@ -656,7 +654,7 @@ static NSData *DataFromCStr(const char *str) {
     Message3 *orig = [[Message3 alloc] init];
     orig.oneofBytes = [@"bar" dataUsingEncoding:NSUTF8StringEncoding];
     XCTAssertEqual(orig.oOneOfCase, Message3_O_OneOfCase_OneofBytes);
-    Message3 *msg = [Message3 parseFromData:[orig data]];
+    Message3 *msg = [Message3 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message3_O_OneOfCase_OneofBytes);
     XCTAssertEqualObjects(msg.oneofBytes, [@"bar" dataUsingEncoding:NSUTF8StringEncoding]);
     [orig release];
@@ -668,7 +666,7 @@ static NSData *DataFromCStr(const char *str) {
     Message3 *orig = [[Message3 alloc] init];
     orig.oneofMessage = subMessage;
     XCTAssertEqual(orig.oOneOfCase, Message3_O_OneOfCase_OneofMessage);
-    Message3 *msg = [Message3 parseFromData:[orig data]];
+    Message3 *msg = [Message3 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message3_O_OneOfCase_OneofMessage);
     XCTAssertEqualObjects(msg.oneofMessage, subMessage);
     [orig release];
@@ -678,7 +676,7 @@ static NSData *DataFromCStr(const char *str) {
     Message3 *orig = [[Message3 alloc] init];
     orig.oneofEnum = Message2_Enum_Bar;
     XCTAssertEqual(orig.oOneOfCase, Message3_O_OneOfCase_OneofEnum);
-    Message3 *msg = [Message3 parseFromData:[orig data]];
+    Message3 *msg = [Message3 parseFromData:[orig data] error:NULL];
     XCTAssertEqual(msg.oOneOfCase, Message3_O_OneOfCase_OneofEnum);
     XCTAssertEqual(msg.oneofEnum, Message2_Enum_Bar);
     [orig release];
@@ -695,7 +693,7 @@ static NSData *DataFromCStr(const char *str) {
 - (void)testMap_StandardWireFormat {
   NSData *data = DataFromCStr("\x0A\x04\x08\x01\x10\x01");
 
-  TestMap *msg = [[TestMap alloc] initWithData:data];
+  TestMap *msg = [[TestMap alloc] initWithData:data error:NULL];
   XCTAssertEqual(msg.mapInt32Int32.count, 1U);
   int32_t val = 666;
   XCTAssertTrue([msg.mapInt32Int32 valueForKey:1 value:&val]);
@@ -709,7 +707,7 @@ static NSData *DataFromCStr(const char *str) {
   // put value before key in wire format
   NSData *data = DataFromCStr("\x0A\x04\x10\x01\x08\x02");
 
-  TestMap *msg = [[TestMap alloc] initWithData:data];
+  TestMap *msg = [[TestMap alloc] initWithData:data error:NULL];
   XCTAssertEqual(msg.mapInt32Int32.count, 1U);
   int32_t val = 666;
   XCTAssertTrue([msg.mapInt32Int32 valueForKey:2 value:&val]);
@@ -723,7 +721,7 @@ static NSData *DataFromCStr(const char *str) {
   // Two key fields in wire format
   NSData *data = DataFromCStr("\x0A\x06\x08\x01\x08\x02\x10\x01");
 
-  TestMap *msg = [[TestMap alloc] initWithData:data];
+  TestMap *msg = [[TestMap alloc] initWithData:data error:NULL];
   XCTAssertEqual(msg.mapInt32Int32.count, 1U);
   int32_t val = 666;
   XCTAssertTrue([msg.mapInt32Int32 valueForKey:2 value:&val]);
@@ -737,7 +735,7 @@ static NSData *DataFromCStr(const char *str) {
   // Two value fields in wire format
   NSData *data = DataFromCStr("\x0A\x06\x08\x01\x10\x01\x10\x02");
 
-  TestMap *msg = [[TestMap alloc] initWithData:data];
+  TestMap *msg = [[TestMap alloc] initWithData:data error:NULL];
   XCTAssertEqual(msg.mapInt32Int32.count, 1U);
   int32_t val = 666;
   XCTAssertTrue([msg.mapInt32Int32 valueForKey:1 value:&val]);
@@ -751,7 +749,7 @@ static NSData *DataFromCStr(const char *str) {
   // No key field in wire format
   NSData *data = DataFromCStr("\x0A\x02\x10\x01");
 
-  TestMap *msg = [[TestMap alloc] initWithData:data];
+  TestMap *msg = [[TestMap alloc] initWithData:data error:NULL];
   XCTAssertEqual(msg.mapInt32Int32.count, 1U);
   int32_t val = 666;
   XCTAssertTrue([msg.mapInt32Int32 valueForKey:0 value:&val]);
@@ -765,7 +763,7 @@ static NSData *DataFromCStr(const char *str) {
   // No value field in wire format
   NSData *data = DataFromCStr("\x0A\x02\x08\x01");
 
-  TestMap *msg = [[TestMap alloc] initWithData:data];
+  TestMap *msg = [[TestMap alloc] initWithData:data error:NULL];
   XCTAssertEqual(msg.mapInt32Int32.count, 1U);
   int32_t val = 666;
   XCTAssertTrue([msg.mapInt32Int32 valueForKey:1 value:&val]);
@@ -779,7 +777,7 @@ static NSData *DataFromCStr(const char *str) {
   // Unknown field in wire format
   NSData *data = DataFromCStr("\x0A\x06\x08\x02\x10\x03\x18\x01");
 
-  TestMap *msg = [[TestMap alloc] initWithData:data];
+  TestMap *msg = [[TestMap alloc] initWithData:data error:NULL];
   XCTAssertEqual(msg.mapInt32Int32.count, 1U);
   int32_t val = 666;
   XCTAssertTrue([msg.mapInt32Int32 valueForKey:2 value:&val]);
@@ -793,8 +791,12 @@ static NSData *DataFromCStr(const char *str) {
   // corrupted data in wire format
   NSData *data = DataFromCStr("\x0A\x06\x08\x02\x11\x03");
 
-  XCTAssertThrowsSpecificNamed([TestMap parseFromData:data], NSException,
-                               NSParseErrorException);
+  NSError *error = nil;
+  TestMap *msg = [TestMap parseFromData:data error:&error];
+  XCTAssertNil(msg);
+  XCTAssertNotNil(error);
+  XCTAssertEqualObjects(error.domain, GPBMessageErrorDomain);
+  XCTAssertEqual(error.code, GPBMessageErrorCodeMalformedData);
 }
 
 // TEST(GeneratedMapFieldTest, Proto2UnknownEnum)
@@ -810,14 +812,15 @@ static NSData *DataFromCStr(const char *str) {
   [orig.unknownMapField setValue:Proto2MapEnumPlusExtra_EProto2MapEnumExtra
                           forKey:0];
 
-  TestEnumMap *msg1 = [TestEnumMap parseFromData:[orig data]];
+  TestEnumMap *msg1 = [TestEnumMap parseFromData:[orig data] error:NULL];
   XCTAssertEqual(msg1.knownMapField.count, 1U);
   int32_t val = -1;
   XCTAssertTrue([msg1.knownMapField valueForKey:0 value:&val]);
   XCTAssertEqual(val, Proto2MapEnum_Proto2MapEnumFoo);
   XCTAssertEqual(msg1.unknownFields.countOfFields, 1U);
 
-  TestEnumMapPlusExtra *msg2 = [TestEnumMapPlusExtra parseFromData:[msg1 data]];
+  TestEnumMapPlusExtra *msg2 =
+      [TestEnumMapPlusExtra parseFromData:[msg1 data] error:NULL];
   val = -1;
   XCTAssertEqual(msg2.knownMapField.count, 1U);
   XCTAssertTrue([msg2.knownMapField valueForKey:0 value:&val]);
@@ -833,6 +836,72 @@ static NSData *DataFromCStr(const char *str) {
   [orig release];
 }
 
-#pragma mark -
+#pragma mark - Map Round Tripping
+
+- (void)testProto2MapRoundTripping {
+  Message2 *msg = [[Message2 alloc] init];
+
+  // Key/Value data should result in different byte lengths on wire to ensure
+  // everything is right.
+  [msg.mapInt32Int32 setValue:1000 forKey:200];
+  [msg.mapInt32Int32 setValue:101 forKey:2001];
+  [msg.mapInt64Int64 setValue:1002 forKey:202];
+  [msg.mapInt64Int64 setValue:103 forKey:2003];
+  [msg.mapUint32Uint32 setValue:1004 forKey:204];
+  [msg.mapUint32Uint32 setValue:105 forKey:2005];
+  [msg.mapUint64Uint64 setValue:1006 forKey:206];
+  [msg.mapUint64Uint64 setValue:107 forKey:2007];
+  [msg.mapSint32Sint32 setValue:1008 forKey:208];
+  [msg.mapSint32Sint32 setValue:109 forKey:2009];
+  [msg.mapSint64Sint64 setValue:1010 forKey:210];
+  [msg.mapSint64Sint64 setValue:111 forKey:2011];
+  [msg.mapFixed32Fixed32 setValue:1012 forKey:212];
+  [msg.mapFixed32Fixed32 setValue:113 forKey:2013];
+  [msg.mapFixed64Fixed64 setValue:1014 forKey:214];
+  [msg.mapFixed64Fixed64 setValue:115 forKey:2015];
+  [msg.mapSfixed32Sfixed32 setValue:1016 forKey:216];
+  [msg.mapSfixed32Sfixed32 setValue:117 forKey:2017];
+  [msg.mapSfixed64Sfixed64 setValue:1018 forKey:218];
+  [msg.mapSfixed64Sfixed64 setValue:119 forKey:2019];
+  [msg.mapInt32Float setValue:1020.f forKey:220];
+  [msg.mapInt32Float setValue:121.f forKey:2021];
+  [msg.mapInt32Double setValue:1022. forKey:222];
+  [msg.mapInt32Double setValue:123. forKey:2023];
+  [msg.mapBoolBool setValue:false forKey:true];
+  [msg.mapBoolBool setValue:true forKey:false];
+  msg.mapStringString[@"224"] = @"1024";
+  msg.mapStringString[@"2025"] = @"125";
+  msg.mapStringBytes[@"226"] = DataFromCStr("1026");
+  msg.mapStringBytes[@"2027"] = DataFromCStr("127");
+  Message2 *val1 = [[Message2 alloc] init];
+  val1.optionalInt32 = 1028;
+  Message2 *val2 = [[Message2 alloc] init];
+  val2.optionalInt32 = 129;
+  [msg.mapStringMessage setValue:val1 forKey:@"228"];
+  [msg.mapStringMessage setValue:val2 forKey:@"2029"];
+  [msg.mapInt32Bytes setValue:DataFromCStr("1030 bytes") forKey:230];
+  [msg.mapInt32Bytes setValue:DataFromCStr("131") forKey:2031];
+  [msg.mapInt32Enum setValue:Message2_Enum_Bar forKey:232];
+  [msg.mapInt32Enum setValue:Message2_Enum_Baz forKey:2033];
+  Message2 *val3 = [[Message2 alloc] init];
+  val3.optionalInt32 = 1034;
+  Message2 *val4 = [[Message2 alloc] init];
+  val4.optionalInt32 = 135;
+  [msg.mapInt32Message setValue:val3 forKey:234];
+  [msg.mapInt32Message setValue:val4 forKey:2035];
+
+  NSData *data = [msg data];
+  Message2 *msg2 = [[Message2 alloc] initWithData:data error:NULL];
+
+  XCTAssertNotEqual(msg2, msg);  // Pointer comparison
+  XCTAssertEqualObjects(msg2, msg);
+
+  [val4 release];
+  [val3 release];
+  [val2 release];
+  [val1 release];
+  [msg2 release];
+  [msg release];
+}
 
 @end
diff --git a/objectivec/Tests/GPBMessageTests.m b/objectivec/Tests/GPBMessageTests.m
index 5ec67cd9..e0154c1a 100644
--- a/objectivec/Tests/GPBMessageTests.m
+++ b/objectivec/Tests/GPBMessageTests.m
@@ -34,6 +34,7 @@
 
 #import "GPBArray_PackagePrivate.h"
 #import "GPBDescriptor.h"
+#import "GPBDictionary_PackagePrivate.h"
 #import "GPBField_PackagePrivate.h"
 #import "GPBMessage_PackagePrivate.h"
 #import "GPBUnknownFieldSet_PackagePrivate.h"
@@ -47,23 +48,9 @@
 @implementation MessageTests
 
 // TODO(thomasvl): this should get split into a few files of logic junks, it is
-// a jumble
-// of things at the moment (and the testutils have a bunch of the real
+// a jumble of things at the moment (and the testutils have a bunch of the real
 // assertions).
 
-#ifdef DEBUG
-- (void)assertBlock:(void (^)())block
-    throwsWithMessageInUserInfo:(GPBMessage *)message {
-  @try {
-    block();
-    XCTAssertTrue(NO);
-  }
-  @catch (NSException *e) {
-    XCTAssertEqualObjects([e userInfo][GPBExceptionMessageKey], message);
-  }
-}
-#endif  // DEBUG
-
 - (TestAllTypes *)mergeSource {
   TestAllTypes *message = [TestAllTypes message];
   [message setOptionalInt32:1];
@@ -290,14 +277,18 @@
   XCTAssertTrue(message.initialized);
 }
 
-#ifdef DEBUG
-- (void)testUninitializedException {
+- (void)testDataFromUninitialized {
   TestRequired *message = [TestRequired message];
-  [self assertBlock:^{
-    [message data];
-  } throwsWithMessageInUserInfo:message];
-}
+  NSData *data = [message data];
+  // In DEBUG, the data generation will fail, but in non DEBUG, it passes
+  // because the check isn't done (for speed).
+#ifdef DEBUG
+  XCTAssertNil(data);
+#else
+  XCTAssertNotNil(data);
+  XCTAssertFalse(message.initialized);
 #endif  // DEBUG
+}
 
 - (void)testInitialized {
   // We're mostly testing that no exception is thrown.
@@ -305,18 +296,22 @@
   XCTAssertFalse(message.initialized);
 }
 
-#ifdef DEBUG
-- (void)testNestedUninitializedException {
+- (void)testDataFromNestedUninitialized {
   TestRequiredForeign *message = [TestRequiredForeign message];
   [message setOptionalMessage:[TestRequired message]];
   message.repeatedMessageArray = [NSMutableArray array];
   [message.repeatedMessageArray addObject:[TestRequired message]];
   [message.repeatedMessageArray addObject:[TestRequired message]];
-  [self assertBlock:^{
-    [message data];
-  } throwsWithMessageInUserInfo:message];
-}
+  NSData *data = [message data];
+  // In DEBUG, the data generation will fail, but in non DEBUG, it passes
+  // because the check isn't done (for speed).
+#ifdef DEBUG
+  XCTAssertNil(data);
+#else
+  XCTAssertNotNil(data);
+  XCTAssertFalse(message.initialized);
 #endif  // DEBUG
+}
 
 - (void)testNestedInitialized {
   // We're mostly testing that no exception is thrown.
@@ -330,13 +325,23 @@
   XCTAssertFalse(message.initialized);
 }
 
-#ifdef DEBUG
 - (void)testParseUninitialized {
-  [self assertBlock:^{
-    [TestRequired parseFromData:GPBEmptyNSData()];
-  } throwsWithMessageInUserInfo:[TestRequired message]];
-}
+  NSError *error = nil;
+  TestRequired *msg =
+      [TestRequired parseFromData:GPBEmptyNSData() error:&error];
+  // In DEBUG, the parse will fail, but in non DEBUG, it passes because
+  // the check isn't done (for speed).
+#ifdef DEBUG
+  XCTAssertNil(msg);
+  XCTAssertNotNil(error);
+  XCTAssertEqualObjects(error.domain, GPBMessageErrorDomain);
+  XCTAssertEqual(error.code, GPBMessageErrorCodeMissingRequiredField);
+#else
+  XCTAssertNotNil(msg);
+  XCTAssertNil(error);
+  XCTAssertFalse(msg.initialized);
 #endif  // DEBUG
+}
 
 - (void)testCoding {
   NSData *data =
@@ -1033,7 +1038,7 @@
   message3.repeatedStringArray = [NSMutableArray arrayWithObject:@"wee"];
   XCTAssertNotNil(message.repeatedInt32Array);
   XCTAssertNotNil(message.repeatedStringArray);
-  TestAllTypes *message4 = [message3 copy];
+  TestAllTypes *message4 = [[message3 copy] autorelease];
   XCTAssertNotEqual(message3.repeatedInt32Array, message4.repeatedInt32Array);
   XCTAssertEqualObjects(message3.repeatedInt32Array,
                         message4.repeatedInt32Array);
@@ -1156,6 +1161,205 @@
   XCTAssertFalse([message hasA]);
 }
 
+- (void)testDefaultingMaps {
+  // Basic tests for default creation of maps in a message.
+  TestRecursiveMessageWithRepeatedField *message =
+      [TestRecursiveMessageWithRepeatedField message];
+  TestRecursiveMessageWithRepeatedField *message2 =
+      [TestRecursiveMessageWithRepeatedField message];
+
+  // Simply accessing the map should not make any fields visible.
+  XCTAssertNotNil(message.a.a.iToI);
+  XCTAssertFalse([message hasA]);
+  XCTAssertFalse([message.a hasA]);
+  XCTAssertNotNil(message2.a.a.strToStr);
+  XCTAssertFalse([message2 hasA]);
+  XCTAssertFalse([message2.a hasA]);
+
+  // But adding an element to the map should.
+  [message.a.a.iToI setValue:100 forKey:200];
+  XCTAssertTrue([message hasA]);
+  XCTAssertTrue([message.a hasA]);
+  XCTAssertEqual([message.a.a.iToI count], (NSUInteger)1);
+  [message2.a.a.strToStr setObject:@"foo" forKey:@"bar"];
+  XCTAssertTrue([message2 hasA]);
+  XCTAssertTrue([message2.a hasA]);
+  XCTAssertEqual([message2.a.a.strToStr count], (NSUInteger)1);
+}
+
+- (void)testAutocreatedMapShared {
+  // Multiple objects pointing to the same map.
+  TestRecursiveMessageWithRepeatedField *message1a =
+      [TestRecursiveMessageWithRepeatedField message];
+  TestRecursiveMessageWithRepeatedField *message1b =
+      [TestRecursiveMessageWithRepeatedField message];
+  message1a.a.iToI = message1b.a.iToI;
+  XCTAssertTrue([message1a hasA]);
+  XCTAssertFalse([message1b hasA]);
+  [message1a.a.iToI setValue:1 forKey:2];
+  XCTAssertTrue([message1a hasA]);
+  XCTAssertTrue([message1b hasA]);
+  XCTAssertEqual(message1a.a.iToI, message1b.a.iToI);
+
+  TestRecursiveMessageWithRepeatedField *message2a =
+      [TestRecursiveMessageWithRepeatedField message];
+  TestRecursiveMessageWithRepeatedField *message2b =
+      [TestRecursiveMessageWithRepeatedField message];
+  message2a.a.strToStr = message2b.a.strToStr;
+  XCTAssertTrue([message2a hasA]);
+  XCTAssertFalse([message2b hasA]);
+  [message2a.a.strToStr setObject:@"bar" forKey:@"foo"];
+  XCTAssertTrue([message2a hasA]);
+  XCTAssertTrue([message2b hasA]);
+  XCTAssertEqual(message2a.a.strToStr, message2b.a.strToStr);
+}
+
+- (void)testAutocreatedMapCopy {
+  // Copy should not copy autocreated maps.
+  TestRecursiveMessageWithRepeatedField *message =
+      [TestRecursiveMessageWithRepeatedField message];
+  XCTAssertNotNil(message.strToStr);
+  XCTAssertNotNil(message.iToI);
+  TestRecursiveMessageWithRepeatedField *message2 =
+      [[message copy] autorelease];
+  // Pointer conparisions.
+  XCTAssertNotEqual(message.strToStr, message2.strToStr);
+  XCTAssertNotEqual(message.iToI, message2.iToI);
+
+  // Mutable copy should copy empty arrays that were explicitly set (end up
+  // with different objects that are equal).
+  TestRecursiveMessageWithRepeatedField *message3 =
+      [TestRecursiveMessageWithRepeatedField message];
+  message3.iToI = [GPBInt32Int32Dictionary dictionaryWithValue:10 forKey:20];
+  message3.strToStr =
+      [NSMutableDictionary dictionaryWithObject:@"abc" forKey:@"123"];
+  XCTAssertNotNil(message.iToI);
+  XCTAssertNotNil(message.iToI);
+  TestRecursiveMessageWithRepeatedField *message4 =
+      [[message3 copy] autorelease];
+  XCTAssertNotEqual(message3.iToI, message4.iToI);
+  XCTAssertEqualObjects(message3.iToI, message4.iToI);
+  XCTAssertNotEqual(message3.strToStr, message4.strToStr);
+  XCTAssertEqualObjects(message3.strToStr, message4.strToStr);
+}
+
+- (void)testAutocreatedMapRetain {
+  // Should be able to retain autocreated map while the creator is dealloced.
+  TestRecursiveMessageWithRepeatedField *message =
+      [TestRecursiveMessageWithRepeatedField message];
+
+  @autoreleasepool {
+    TestRecursiveMessageWithRepeatedField *message2 =
+        [TestRecursiveMessageWithRepeatedField message];
+    message.iToI = message2.iToI;
+    message.strToStr = message2.strToStr;
+    // Pointer conparision
+    XCTAssertEqual(message.iToI->_autocreator, message2);
+    XCTAssertTrue([message.strToStr
+        isKindOfClass:[GPBAutocreatedDictionary class]]);
+    XCTAssertEqual(
+        ((GPBAutocreatedDictionary *)message.strToStr)->_autocreator,
+        message2);
+  }
+
+  XCTAssertNil(message.iToI->_autocreator);
+  XCTAssertTrue(
+      [message.strToStr isKindOfClass:[GPBAutocreatedDictionary class]]);
+  XCTAssertNil(
+      ((GPBAutocreatedDictionary *)message.strToStr)->_autocreator);
+}
+
+- (void)testSetNilAutocreatedMap {
+  // Setting map to nil should cause it to lose its delegate.
+  TestRecursiveMessageWithRepeatedField *message =
+      [TestRecursiveMessageWithRepeatedField message];
+  GPBInt32Int32Dictionary *iToI = [message.iToI retain];
+  GPBAutocreatedDictionary *strToStr =
+      (GPBAutocreatedDictionary *)[message.strToStr retain];
+  XCTAssertTrue([strToStr isKindOfClass:[GPBAutocreatedDictionary class]]);
+  XCTAssertEqual(iToI->_autocreator, message);
+  XCTAssertEqual(strToStr->_autocreator, message);
+  message.iToI = nil;
+  message.strToStr = nil;
+  XCTAssertNil(iToI->_autocreator);
+  XCTAssertNil(strToStr->_autocreator);
+  [iToI release];
+  [strToStr release];
+}
+
+- (void)testReplaceAutocreatedMap {
+  // Replacing map should orphan the old one and cause its creator to become
+  // visible.
+  {
+    TestRecursiveMessageWithRepeatedField *message =
+        [TestRecursiveMessageWithRepeatedField message];
+    XCTAssertNotNil(message.a);
+    XCTAssertNotNil(message.a.iToI);
+    XCTAssertFalse([message hasA]);
+    GPBInt32Int32Dictionary *iToI = [message.a.iToI retain];
+    XCTAssertEqual(iToI->_autocreator, message.a);  // Pointer comparision
+    message.a.iToI = [GPBInt32Int32Dictionary dictionaryWithValue:6 forKey:7];
+    XCTAssertTrue([message hasA]);
+    XCTAssertNotEqual(message.a.iToI, iToI);  // Pointer comparision
+    XCTAssertNil(iToI->_autocreator);
+    [iToI release];
+  }
+
+  {
+    TestRecursiveMessageWithRepeatedField *message =
+        [TestRecursiveMessageWithRepeatedField message];
+    XCTAssertNotNil(message.a);
+    XCTAssertNotNil(message.a.strToStr);
+    XCTAssertFalse([message hasA]);
+    GPBAutocreatedDictionary *strToStr =
+        (GPBAutocreatedDictionary *)[message.a.strToStr retain];
+    XCTAssertTrue([strToStr isKindOfClass:[GPBAutocreatedDictionary class]]);
+    XCTAssertEqual(strToStr->_autocreator, message.a);  // Pointer comparision
+    message.a.strToStr =
+        [NSMutableDictionary dictionaryWithObject:@"abc" forKey:@"def"];
+    XCTAssertTrue([message hasA]);
+    XCTAssertNotEqual(message.a.strToStr, strToStr);  // Pointer comparision
+    XCTAssertNil(strToStr->_autocreator);
+    [strToStr release];
+  }
+}
+
+- (void)testSetAutocreatedMapToSelf {
+  // Setting map to itself should cause it to become visible.
+  {
+    TestRecursiveMessageWithRepeatedField *message =
+        [TestRecursiveMessageWithRepeatedField message];
+    XCTAssertNotNil(message.a);
+    XCTAssertNotNil(message.a.iToI);
+    XCTAssertFalse([message hasA]);
+    message.a.iToI = message.a.iToI;
+    XCTAssertTrue([message hasA]);
+    XCTAssertNil(message.a.iToI->_autocreator);
+  }
+
+  {
+    TestRecursiveMessageWithRepeatedField *message =
+        [TestRecursiveMessageWithRepeatedField message];
+    XCTAssertNotNil(message.a);
+    XCTAssertNotNil(message.a.strToStr);
+    XCTAssertFalse([message hasA]);
+    message.a.strToStr = message.a.strToStr;
+    XCTAssertTrue([message hasA]);
+    XCTAssertTrue([message.a.strToStr isKindOfClass:[GPBAutocreatedDictionary class]]);
+    XCTAssertNil(((GPBAutocreatedDictionary *)message.a.strToStr)->_autocreator);
+  }
+}
+
+- (void)testAutocreatedMapRemoveAllValues {
+  // Calling removeAll on autocreated map should not cause it to be visible.
+  TestRecursiveMessageWithRepeatedField *message =
+      [TestRecursiveMessageWithRepeatedField message];
+  [message.a.iToI removeAll];
+  XCTAssertFalse([message hasA]);
+  [message.a.strToStr removeAllObjects];
+  XCTAssertFalse([message hasA]);
+}
+
 - (void)testExtensionAccessors {
   TestAllExtensions *message = [TestAllExtensions message];
   [self setAllExtensions:message repeatedCount:kGPBDefaultRepeatCount];
@@ -1555,7 +1759,8 @@
   GPBMessage *message = [GPBMessage message];
   [message setUnknownFields:unknowns];
   NSData *data = [message data];
-  GPBMessage *message2 = [GPBMessage parseFromData:data extensionRegistry:nil];
+  GPBMessage *message2 =
+      [GPBMessage parseFromData:data extensionRegistry:nil error:NULL];
   XCTAssertEqualObjects(message, message2);
 }
 
@@ -1579,9 +1784,11 @@
   GPBCodedInputStream *input =
       [GPBCodedInputStream streamWithData:delimitedData];
   GPBMessage *message3 = [GPBMessage parseDelimitedFromCodedInputStream:input
-                                                      extensionRegistry:nil];
+                                                      extensionRegistry:nil
+                                                                  error:NULL];
   GPBMessage *message4 = [GPBMessage parseDelimitedFromCodedInputStream:input
-                                                      extensionRegistry:nil];
+                                                      extensionRegistry:nil
+                                                                  error:NULL];
   XCTAssertEqualObjects(message1, message3);
   XCTAssertEqualObjects(message2, message4);
 }
@@ -1673,7 +1880,7 @@
   XCTAssertEqual(msg.bar, EnumTestMsg_MyEnum_One);
   XCTAssertEqual(msg.baz, EnumTestMsg_MyEnum_NegOne);
   // Bounce to wire and back.
-  EnumTestMsg *msgPrime = [EnumTestMsg parseFromData:[msg data]];
+  EnumTestMsg *msgPrime = [EnumTestMsg parseFromData:[msg data] error:NULL];
   XCTAssertEqualObjects(msgPrime, msg);
   XCTAssertEqual(msgPrime.foo, EnumTestMsg_MyEnum_Zero);
   XCTAssertEqual(msgPrime.bar, EnumTestMsg_MyEnum_One);
@@ -1685,7 +1892,7 @@
   XCTAssertEqual(msg.bar, EnumTestMsg_MyEnum_Two);
   XCTAssertEqual(msg.baz, EnumTestMsg_MyEnum_NegTwo);
   // Bounce to wire and back.
-  msgPrime = [EnumTestMsg parseFromData:[msg data]];
+  msgPrime = [EnumTestMsg parseFromData:[msg data] error:NULL];
   XCTAssertEqualObjects(msgPrime, msg);
   XCTAssertEqual(msgPrime.foo, EnumTestMsg_MyEnum_Zero);
   XCTAssertEqual(msgPrime.bar, EnumTestMsg_MyEnum_Two);
@@ -1706,7 +1913,7 @@
   XCTAssertEqual([msg.mumbleArray valueAtIndex:3], EnumTestMsg_MyEnum_NegOne);
   XCTAssertEqual([msg.mumbleArray valueAtIndex:4], EnumTestMsg_MyEnum_NegTwo);
   // Bounce to wire and back.
-  msgPrime = [EnumTestMsg parseFromData:[msg data]];
+  msgPrime = [EnumTestMsg parseFromData:[msg data] error:NULL];
   XCTAssertEqualObjects(msgPrime, msg);
   XCTAssertEqual([msgPrime.mumbleArray valueAtIndex:0],
                  EnumTestMsg_MyEnum_Zero);
diff --git a/objectivec/Tests/GPBPerfTests.m b/objectivec/Tests/GPBPerfTests.m
index d09021af..1259d146 100644
--- a/objectivec/Tests/GPBPerfTests.m
+++ b/objectivec/Tests/GPBPerfTests.m
@@ -30,6 +30,7 @@
 
 #import "GPBTestUtilities.h"
 #import "google/protobuf/Unittest.pbobjc.h"
+#import "google/protobuf/UnittestImport.pbobjc.h"
 #import "google/protobuf/UnittestObjc.pbobjc.h"
 
 //
@@ -57,7 +58,7 @@ static const uint32_t kRepeatedCount = 100;
       [self setAllFields:message repeatedCount:kRepeatedCount];
       NSData* rawBytes = [message data];
       [message release];
-      message = [[TestAllTypes alloc] initWithData:rawBytes];
+      message = [[TestAllTypes alloc] initWithData:rawBytes error:NULL];
       [message release];
     }
   }];
@@ -71,7 +72,7 @@ static const uint32_t kRepeatedCount = 100;
       NSData* rawBytes = [message data];
       [message release];
       TestAllExtensions* message2 =
-          [[TestAllExtensions alloc] initWithData:rawBytes];
+          [[TestAllExtensions alloc] initWithData:rawBytes error:NULL];
       [message2 release];
     }
   }];
@@ -84,7 +85,7 @@ static const uint32_t kRepeatedCount = 100;
       [self setPackedFields:message repeatedCount:kRepeatedCount];
       NSData* rawBytes = [message data];
       [message release];
-      message = [[TestPackedTypes alloc] initWithData:rawBytes];
+      message = [[TestPackedTypes alloc] initWithData:rawBytes error:NULL];
       [message release];
     }
   }];
@@ -98,7 +99,7 @@ static const uint32_t kRepeatedCount = 100;
       NSData* rawBytes = [message data];
       [message release];
       TestPackedExtensions* message2 =
-          [[TestPackedExtensions alloc] initWithData:rawBytes];
+          [[TestPackedExtensions alloc] initWithData:rawBytes error:NULL];
       [message2 release];
     }
   }];
diff --git a/objectivec/Tests/GPBStringTests.m b/objectivec/Tests/GPBStringTests.m
index 30f13775..802afa7d 100644
--- a/objectivec/Tests/GPBStringTests.m
+++ b/objectivec/Tests/GPBStringTests.m
@@ -31,10 +31,7 @@
 #import <XCTest/XCTest.h>
 
 #import "GPBCodedInputStream_PackagePrivate.h"
-
-#ifndef GPBARRAYSIZE
-#define GPBARRAYSIZE(a) ((sizeof(a) / sizeof((a[0]))))
-#endif  // GPBARRAYSIZE
+#import "GPBTestUtilities.h"
 
 @interface TestClass : NSObject
 @property(nonatomic, retain) NSString *foo;
diff --git a/objectivec/Tests/GPBSwiftTests.swift b/objectivec/Tests/GPBSwiftTests.swift
index e7b6f94c..30b9cbd4 100644
--- a/objectivec/Tests/GPBSwiftTests.swift
+++ b/objectivec/Tests/GPBSwiftTests.swift
@@ -53,6 +53,12 @@ class GPBBridgeTests: XCTestCase {
     msg.repeatedStringArray.addObject("pqr")
     msg.repeatedEnumArray.addValue(Message2_Enum.Bar.rawValue)
     msg.repeatedEnumArray.addValue(Message2_Enum.Baz.rawValue)
+    msg.mapInt32Int32.setValue(400, forKey:500)
+    msg.mapInt32Int32.setValue(401, forKey:501)
+    msg.mapStringString.setObject("foo", forKey:"bar")
+    msg.mapStringString.setObject("abc", forKey:"xyz")
+    msg.mapInt32Enum.setValue(Message2_Enum.Bar.rawValue, forKey:600)
+    msg.mapInt32Enum.setValue(Message2_Enum.Baz.rawValue, forKey:601)
 
     // Check has*.
     XCTAssertTrue(msg.hasOptionalInt32)
@@ -83,6 +89,20 @@ class GPBBridgeTests: XCTestCase {
     XCTAssertEqual(msg.repeatedEnumArray.valueAtIndex(0), Message2_Enum.Bar.rawValue)
     XCTAssertEqual(msg.repeatedEnumArray.valueAtIndex(1), Message2_Enum.Baz.rawValue)
     XCTAssertEqual(msg.repeatedInt64Array.count, UInt(0))
+    XCTAssertEqual(msg.mapInt32Int32.count, UInt(2))
+    var intValue: Int32 = 0;
+    XCTAssertTrue(msg.mapInt32Int32.valueForKey(500, value:&intValue))
+    XCTAssertEqual(intValue, Int32(400))
+    XCTAssertTrue(msg.mapInt32Int32.valueForKey(501, value:&intValue))
+    XCTAssertEqual(intValue, Int32(401))
+    XCTAssertEqual(msg.mapStringString.count, Int(2))
+    XCTAssertEqual(msg.mapStringString.objectForKey("bar") as! String, "foo")
+    XCTAssertEqual(msg.mapStringString.objectForKey("xyz") as! String, "abc")
+    XCTAssertEqual(msg.mapInt32Enum.count, UInt(2))
+    XCTAssertTrue(msg.mapInt32Enum.valueForKey(600, value:&intValue))
+    XCTAssertEqual(intValue, Message2_Enum.Bar.rawValue)
+    XCTAssertTrue(msg.mapInt32Enum.valueForKey(601, value:&intValue))
+    XCTAssertEqual(intValue, Message2_Enum.Baz.rawValue)
 
     // Clearing a string with nil.
     msg2.optionalString = nil
@@ -109,6 +129,9 @@ class GPBBridgeTests: XCTestCase {
     XCTAssertEqual(msg.repeatedInt32Array.count, UInt(0))
     XCTAssertEqual(msg.repeatedStringArray.count, Int(0))
     XCTAssertEqual(msg.repeatedEnumArray.count, UInt(0))
+    XCTAssertEqual(msg.mapInt32Int32.count, UInt(0))
+    XCTAssertEqual(msg.mapStringString.count, Int(0))
+    XCTAssertEqual(msg.mapInt32Enum.count, UInt(0))
   }
 
   func testProto3Basics() {
@@ -128,6 +151,13 @@ class GPBBridgeTests: XCTestCase {
     msg.repeatedEnumArray.addValue(Message3_Enum.Bar.rawValue)
     msg.repeatedEnumArray.addRawValue(666)
     SetMessage3_OptionalEnum_RawValue(msg2, 666)
+    msg.mapInt32Int32.setValue(400, forKey:500)
+    msg.mapInt32Int32.setValue(401, forKey:501)
+    msg.mapStringString.setObject("foo", forKey:"bar")
+    msg.mapStringString.setObject("abc", forKey:"xyz")
+    msg.mapInt32Enum.setValue(Message2_Enum.Bar.rawValue, forKey:600)
+    // "proto3" syntax lets enum get unknown values.
+    msg.mapInt32Enum.setRawValue(666, forKey:601)
 
     // Has only exists on for message fields.
     XCTAssertTrue(msg.hasOptionalMessage)
@@ -152,6 +182,22 @@ class GPBBridgeTests: XCTestCase {
     XCTAssertEqual(msg.repeatedEnumArray.rawValueAtIndex(1), 666)
     XCTAssertEqual(msg2.optionalEnum, Message3_Enum.GPBUnrecognizedEnumeratorValue)
     XCTAssertEqual(Message3_OptionalEnum_RawValue(msg2), Int32(666))
+    XCTAssertEqual(msg.mapInt32Int32.count, UInt(2))
+    var intValue: Int32 = 0;
+    XCTAssertTrue(msg.mapInt32Int32.valueForKey(500, value:&intValue))
+    XCTAssertEqual(intValue, Int32(400))
+    XCTAssertTrue(msg.mapInt32Int32.valueForKey(501, value:&intValue))
+    XCTAssertEqual(intValue, Int32(401))
+    XCTAssertEqual(msg.mapStringString.count, Int(2))
+    XCTAssertEqual(msg.mapStringString.objectForKey("bar") as! String, "foo")
+    XCTAssertEqual(msg.mapStringString.objectForKey("xyz") as! String, "abc")
+    XCTAssertEqual(msg.mapInt32Enum.count, UInt(2))
+    XCTAssertTrue(msg.mapInt32Enum.valueForKey(600, value:&intValue))
+    XCTAssertEqual(intValue, Message2_Enum.Bar.rawValue)
+    XCTAssertTrue(msg.mapInt32Enum.valueForKey(601, value:&intValue))
+    XCTAssertEqual(intValue, Message3_Enum.GPBUnrecognizedEnumeratorValue.rawValue)
+    XCTAssertTrue(msg.mapInt32Enum.valueForKey(601, rawValue:&intValue))
+    XCTAssertEqual(intValue, 666)
 
     // Clearing a string with nil.
     msg2.optionalString = nil
@@ -175,6 +221,9 @@ class GPBBridgeTests: XCTestCase {
     msg2.clear()
     XCTAssertEqual(msg2.optionalEnum, Message3_Enum.Foo)  // Default
     XCTAssertEqual(Message3_OptionalEnum_RawValue(msg2), Message3_Enum.Foo.rawValue)
+    XCTAssertEqual(msg.mapInt32Int32.count, UInt(0))
+    XCTAssertEqual(msg.mapStringString.count, Int(0))
+    XCTAssertEqual(msg.mapInt32Enum.count, UInt(0))
   }
 
   func testAutoCreation() {
@@ -390,15 +439,21 @@ class GPBBridgeTests: XCTestCase {
     msg.optionalGroup.a = 102
     msg.repeatedStringArray.addObject("abc")
     msg.repeatedStringArray.addObject("def")
+    msg.mapInt32Int32.setValue(200, forKey:300)
+    msg.mapInt32Int32.setValue(201, forKey:201)
+    msg.mapStringString.setObject("foo", forKey:"bar")
+    msg.mapStringString.setObject("abc", forKey:"xyz")
 
     let data = msg.data()
 
-    let msg2 = Message2(data: data)
+    let msg2 = Message2(data: data, error:nil)
     XCTAssertTrue(msg2 !== msg)  // New instance
     XCTAssertEqual(msg.optionalInt32, Int32(100))
     XCTAssertEqual(msg.optionalInt64, Int64(101))
     XCTAssertEqual(msg.optionalGroup.a, Int32(102))
     XCTAssertEqual(msg.repeatedStringArray.count, Int(2))
+    XCTAssertEqual(msg.mapInt32Int32.count, UInt(2))
+    XCTAssertEqual(msg.mapStringString.count, Int(2))
     XCTAssertEqual(msg2, msg)
   }
 
diff --git a/objectivec/Tests/GPBTestUtilities.h b/objectivec/Tests/GPBTestUtilities.h
index 37e30f96..6ae68c3a 100644
--- a/objectivec/Tests/GPBTestUtilities.h
+++ b/objectivec/Tests/GPBTestUtilities.h
@@ -37,6 +37,13 @@
 @class TestPackedExtensions;
 @class GPBExtensionRegistry;
 
+
+// Helper for uses of C arrays in tests cases.
+#ifndef GPBARRAYSIZE
+#define GPBARRAYSIZE(a) ((sizeof(a) / sizeof((a[0]))))
+#endif  // GPBARRAYSIZE
+
+
 // The number of repetitions of any repeated objects inside of test messages.
 extern const uint32_t kGPBDefaultRepeatCount;
 
diff --git a/objectivec/Tests/GPBTestUtilities.m b/objectivec/Tests/GPBTestUtilities.m
index d664a88a..6058dfc1 100644
--- a/objectivec/Tests/GPBTestUtilities.m
+++ b/objectivec/Tests/GPBTestUtilities.m
@@ -32,6 +32,7 @@
 
 #import "google/protobuf/MapUnittest.pbobjc.h"
 #import "google/protobuf/Unittest.pbobjc.h"
+#import "google/protobuf/UnittestImport.pbobjc.h"
 
 const uint32_t kGPBDefaultRepeatCount = 2;
 
@@ -1060,25 +1061,6 @@ const uint32_t kGPBDefaultRepeatCount = 2;
 }
 
 - (void)setAllMapFields:(TestMap *)message numEntries:(uint32_t)count {
-  message.mapInt32Int32 = [GPBInt32Int32Dictionary dictionary];
-  message.mapInt64Int64 = [GPBInt64Int64Dictionary dictionary];
-  message.mapUint32Uint32 = [GPBUInt32UInt32Dictionary dictionary];
-  message.mapUint64Uint64 = [GPBUInt64UInt64Dictionary dictionary];
-  message.mapSint32Sint32 = [GPBInt32Int32Dictionary dictionary];
-  message.mapSint64Sint64 = [GPBInt64Int64Dictionary dictionary];
-  message.mapFixed32Fixed32 = [GPBUInt32UInt32Dictionary dictionary];
-  message.mapFixed64Fixed64 = [GPBUInt64UInt64Dictionary dictionary];
-  message.mapSfixed32Sfixed32 = [GPBInt32Int32Dictionary dictionary];
-  message.mapSfixed64Sfixed64 = [GPBInt64Int64Dictionary dictionary];
-  message.mapInt32Float = [GPBInt32FloatDictionary dictionary];
-  message.mapInt32Double = [GPBInt32DoubleDictionary dictionary];
-  message.mapBoolBool = [GPBBoolBoolDictionary dictionary];
-  message.mapStringString = [NSMutableDictionary dictionary];
-  message.mapInt32Bytes = [GPBInt32ObjectDictionary dictionary];
-  message.mapInt32Enum = [GPBInt32EnumDictionary
-      dictionaryWithValidationFunction:MapEnum_IsValidValue];
-  message.mapInt32ForeignMessage = [GPBInt32ObjectDictionary dictionary];
-
   for (uint32_t i = 0; i < count; i++) {
     [message.mapInt32Int32 setValue:(i + 1) forKey:100 + i * 100];
     [message.mapInt64Int64 setValue:(i + 1) forKey:101 + i * 100];
diff --git a/objectivec/Tests/GPBUnknownFieldSetTest.m b/objectivec/Tests/GPBUnknownFieldSetTest.m
index 80186088..491bba9e 100644
--- a/objectivec/Tests/GPBUnknownFieldSetTest.m
+++ b/objectivec/Tests/GPBUnknownFieldSetTest.m
@@ -56,7 +56,7 @@
 - (void)setUp {
   allFields_ = [self allSetRepeatedCount:kGPBDefaultRepeatCount];
   allFieldsData_ = [allFields_ data];
-  emptyMessage_ = [TestEmptyMessage parseFromData:allFieldsData_];
+  emptyMessage_ = [TestEmptyMessage parseFromData:allFieldsData_ error:NULL];
   unknownFields_ = emptyMessage_.unknownFields;
 }
 
@@ -176,7 +176,7 @@
   [fields addField:field];
 
   NSData* data = fields.data;
-  TestAllTypes* destination = [TestAllTypes parseFromData:data];
+  TestAllTypes* destination = [TestAllTypes parseFromData:data error:NULL];
 
   [self assertAllFieldsSet:destination repeatedCount:kGPBDefaultRepeatCount];
   XCTAssertEqual(destination.unknownFields.countOfFields, (NSUInteger)1);
@@ -191,8 +191,10 @@
   // when parsing.
 
   NSData* bizarroData = [self getBizarroData];
-  TestAllTypes* allTypesMessage = [TestAllTypes parseFromData:bizarroData];
-  TestEmptyMessage* emptyMessage = [TestEmptyMessage parseFromData:bizarroData];
+  TestAllTypes* allTypesMessage =
+      [TestAllTypes parseFromData:bizarroData error:NULL];
+  TestEmptyMessage* emptyMessage =
+      [TestEmptyMessage parseFromData:bizarroData error:NULL];
 
   // All fields should have been interpreted as unknown, so the debug strings
   // should be the same.
@@ -204,7 +206,7 @@
   // they are declared as extension numbers.
 
   TestEmptyMessageWithExtensions* message =
-      [TestEmptyMessageWithExtensions parseFromData:allFieldsData_];
+      [TestEmptyMessageWithExtensions parseFromData:allFieldsData_ error:NULL];
 
   XCTAssertEqual(unknownFields_.countOfFields,
                  message.unknownFields.countOfFields);
@@ -217,8 +219,9 @@
 
   NSData* bizarroData = [self getBizarroData];
   TestAllExtensions* allExtensionsMessage =
-      [TestAllExtensions parseFromData:bizarroData];
-  TestEmptyMessage* emptyMessage = [TestEmptyMessage parseFromData:bizarroData];
+      [TestAllExtensions parseFromData:bizarroData error:NULL];
+  TestEmptyMessage* emptyMessage =
+      [TestEmptyMessage parseFromData:bizarroData error:NULL];
 
   // All fields should have been interpreted as unknown, so the debug strings
   // should be the same.
diff --git a/objectivec/Tests/GPBWireFormatTests.m b/objectivec/Tests/GPBWireFormatTests.m
index 1344af08..fc5c4bda 100644
--- a/objectivec/Tests/GPBWireFormatTests.m
+++ b/objectivec/Tests/GPBWireFormatTests.m
@@ -47,7 +47,7 @@
   NSData* rawBytes = message.data;
   XCTAssertEqual(message.serializedSize, (size_t)rawBytes.length);
 
-  TestAllTypes* message2 = [TestAllTypes parseFromData:rawBytes];
+  TestAllTypes* message2 = [TestAllTypes parseFromData:rawBytes error:NULL];
 
   [self assertAllFieldsSet:message2 repeatedCount:kGPBDefaultRepeatCount];
 }
@@ -59,7 +59,8 @@
   NSData* rawBytes = message.data;
   XCTAssertEqual(message.serializedSize, (size_t)rawBytes.length);
 
-  TestPackedTypes* message2 = [TestPackedTypes parseFromData:rawBytes];
+  TestPackedTypes* message2 =
+      [TestPackedTypes parseFromData:rawBytes error:NULL];
 
   [self assertPackedFieldsSet:message2 repeatedCount:kGPBDefaultRepeatCount];
 }
@@ -74,7 +75,7 @@
   NSData* rawBytes = message.data;
   XCTAssertEqual(message.serializedSize, (size_t)rawBytes.length);
 
-  TestAllTypes* message2 = [TestAllTypes parseFromData:rawBytes];
+  TestAllTypes* message2 = [TestAllTypes parseFromData:rawBytes error:NULL];
 
   [self assertAllFieldsSet:message2 repeatedCount:kGPBDefaultRepeatCount];
 }
@@ -103,8 +104,9 @@
 
   GPBExtensionRegistry* registry = [self extensionRegistry];
 
-  TestAllExtensions* message2 =
-      [TestAllExtensions parseFromData:rawBytes extensionRegistry:registry];
+  TestAllExtensions* message2 = [TestAllExtensions parseFromData:rawBytes
+                                               extensionRegistry:registry
+                                                           error:NULL];
 
   [self assertAllExtensionsSet:message2 repeatedCount:kGPBDefaultRepeatCount];
 }
@@ -124,8 +126,9 @@
 
   GPBExtensionRegistry* registry = [self extensionRegistry];
 
-  TestPackedExtensions* message2 =
-      [TestPackedExtensions parseFromData:rawBytes extensionRegistry:registry];
+  TestPackedExtensions* message2 = [TestPackedExtensions parseFromData:rawBytes
+                                                     extensionRegistry:registry
+                                                                 error:NULL];
 
   [self assertPackedExtensionsSet:message2
                     repeatedCount:kGPBDefaultRepeatCount];
@@ -151,7 +154,7 @@ const int kUnknownTypeId = 1550055;
   NSData* data = [message_set data];
 
   // Parse back using RawMessageSet and check the contents.
-  RawMessageSet* raw = [RawMessageSet parseFromData:data];
+  RawMessageSet* raw = [RawMessageSet parseFromData:data error:NULL];
 
   XCTAssertEqual([raw.unknownFields countOfFields], (NSUInteger)0);
 
@@ -163,11 +166,13 @@ const int kUnknownTypeId = 1550055;
   XCTAssertEqual([raw.itemArray[2] typeId], kUnknownTypeId);
 
   TestMessageSetExtension1* message1 =
-      [TestMessageSetExtension1 parseFromData:[raw.itemArray[0] message]];
+      [TestMessageSetExtension1 parseFromData:[raw.itemArray[0] message]
+                                        error:NULL];
   XCTAssertEqual(message1.i, 123);
 
   TestMessageSetExtension2* message2 =
-      [TestMessageSetExtension2 parseFromData:[raw.itemArray[1] message]];
+      [TestMessageSetExtension2 parseFromData:[raw.itemArray[1] message]
+                                        error:NULL];
   XCTAssertEqualObjects(message2.str, @"foo");
 
   XCTAssertEqualObjects([raw.itemArray[2] message],
@@ -209,7 +214,8 @@ const int kUnknownTypeId = 1550055;
   // Parse as a TestMessageSet and check the contents.
   TestMessageSet* messageSet =
       [TestMessageSet parseFromData:data
-                  extensionRegistry:[UnittestMsetRoot extensionRegistry]];
+                  extensionRegistry:[UnittestMsetRoot extensionRegistry]
+                              error:NULL];
 
   XCTAssertEqual(
       [[messageSet
diff --git a/objectivec/Tests/unittest_objc.proto b/objectivec/Tests/unittest_objc.proto
index d288a30d..3bb92761 100644
--- a/objectivec/Tests/unittest_objc.proto
+++ b/objectivec/Tests/unittest_objc.proto
@@ -44,6 +44,8 @@ message TestRecursiveMessageWithRepeatedField {
   optional TestRecursiveMessageWithRepeatedField a = 1;
   repeated int32 i = 2;
   repeated string str = 3;
+  map<int32, int32> i_to_i = 4;
+  map<string, string> str_to_str = 5;
 }
 
 // Recursive message and extension to for testing autocreators at different
diff --git a/objectivec/Tests/unittest_runtime_proto2.proto b/objectivec/Tests/unittest_runtime_proto2.proto
index f9fd3c35..12a2da68 100644
--- a/objectivec/Tests/unittest_runtime_proto2.proto
+++ b/objectivec/Tests/unittest_runtime_proto2.proto
@@ -105,4 +105,25 @@ message Message2 {
      Message2 oneof_message = 68;
      Enum        oneof_enum = 69 [default = BAZ];
   }
+
+  // Some token map cases, too many combinations to list them all.
+  map<int32   , int32   > map_int32_int32       = 70;
+  map<int64   , int64   > map_int64_int64       = 71;
+  map<uint32  , uint32  > map_uint32_uint32     = 72;
+  map<uint64  , uint64  > map_uint64_uint64     = 73;
+  map<sint32  , sint32  > map_sint32_sint32     = 74;
+  map<sint64  , sint64  > map_sint64_sint64     = 75;
+  map<fixed32 , fixed32 > map_fixed32_fixed32   = 76;
+  map<fixed64 , fixed64 > map_fixed64_fixed64   = 77;
+  map<sfixed32, sfixed32> map_sfixed32_sfixed32 = 78;
+  map<sfixed64, sfixed64> map_sfixed64_sfixed64 = 79;
+  map<int32   , float   > map_int32_float       = 80;
+  map<int32   , double  > map_int32_double      = 81;
+  map<bool    , bool    > map_bool_bool         = 82;
+  map<string  , string  > map_string_string     = 83;
+  map<string  , bytes   > map_string_bytes      = 84;
+  map<string  , Message2> map_string_message    = 85;
+  map<int32   , bytes   > map_int32_bytes       = 86;
+  map<int32   , Enum    > map_int32_enum        = 87;
+  map<int32   , Message2> map_int32_message     = 88;
 }
diff --git a/objectivec/Tests/unittest_runtime_proto3.proto b/objectivec/Tests/unittest_runtime_proto3.proto
index b6a2f4dc..feb7029d 100644
--- a/objectivec/Tests/unittest_runtime_proto3.proto
+++ b/objectivec/Tests/unittest_runtime_proto3.proto
@@ -98,4 +98,25 @@ message Message3 {
     Message3 oneof_message  = 68;
         Enum oneof_enum     = 69;
   }
+
+  // Some token map cases, too many combinations to list them all.
+  map<int32   , int32   > map_int32_int32       = 70;
+  map<int64   , int64   > map_int64_int64       = 71;
+  map<uint32  , uint32  > map_uint32_uint32     = 72;
+  map<uint64  , uint64  > map_uint64_uint64     = 73;
+  map<sint32  , sint32  > map_sint32_sint32     = 74;
+  map<sint64  , sint64  > map_sint64_sint64     = 75;
+  map<fixed32 , fixed32 > map_fixed32_fixed32   = 76;
+  map<fixed64 , fixed64 > map_fixed64_fixed64   = 77;
+  map<sfixed32, sfixed32> map_sfixed32_sfixed32 = 78;
+  map<sfixed64, sfixed64> map_sfixed64_sfixed64 = 79;
+  map<int32   , float   > map_int32_float       = 80;
+  map<int32   , double  > map_int32_double      = 81;
+  map<bool    , bool    > map_bool_bool         = 82;
+  map<string  , string  > map_string_string     = 83;
+  map<string  , bytes   > map_string_bytes      = 84;
+  map<string  , Message3> map_string_message    = 85;
+  map<int32   , bytes   > map_int32_bytes       = 86;
+  map<int32   , Enum    > map_int32_enum        = 87;
+  map<int32   , Message3> map_int32_message     = 88;
 }
diff --git a/objectivec/generate_descriptors_proto.sh b/objectivec/generate_descriptors_proto.sh
new file mode 100755
index 00000000..f2ed00b7
--- /dev/null
+++ b/objectivec/generate_descriptors_proto.sh
@@ -0,0 +1,54 @@
+#!/bin/bash
+
+# Run this script to regenerate descriptor.pbobjc.{h,m} after the protocol
+# compiler changes.
+
+# HINT:  Flags passed to generate_descriptor_proto.sh will be passed directly
+#   to make when building protoc.  This is particularly useful for passing
+#   -j4 to run 4 jobs simultaneously.
+
+set -eu
+
+readonly ScriptDir=$(dirname "$(echo $0 | sed -e "s,^\([^/]\),$(pwd)/\1,")")
+readonly ProtoRootDir="${ScriptDir}/.."
+readonly ProtoC="${ProtoRootDir}/src/protoc"
+
+pushd "${ProtoRootDir}" > /dev/null
+
+if test ! -e src/google/protobuf/stubs/common.h; then
+  cat >&2 << __EOF__
+Could not find source code.  Make sure you are running this script from the
+root of the distribution tree.
+__EOF__
+  exit 1
+fi
+
+if test ! -e src/Makefile; then
+  cat >&2 << __EOF__
+Could not find src/Makefile.  You must run ./configure (and perhaps
+./autogen.sh) first.
+__EOF__
+  exit 1
+fi
+
+# Make sure the compiler is current.
+cd src
+make $@ google/protobuf/stubs/pbconfig.h
+make $@ protoc
+
+declare -a RUNTIME_PROTO_FILES=(\
+  google/protobuf/any.proto \
+  google/protobuf/api.proto \
+  google/protobuf/descriptor.proto \
+  google/protobuf/duration.proto \
+  google/protobuf/empty.proto \
+  google/protobuf/field_mask.proto \
+  google/protobuf/source_context.proto \
+  google/protobuf/struct.proto \
+  google/protobuf/timestamp.proto \
+  google/protobuf/type.proto \
+  google/protobuf/wrappers.proto)
+
+./protoc --objc_out="${ProtoRootDir}/objectivec" ${RUNTIME_PROTO_FILES[@]}
+
+popd > /dev/null
diff --git a/objectivec/google/protobuf/Any.pbobjc.h b/objectivec/google/protobuf/Any.pbobjc.h
new file mode 100644
index 00000000..8154318e
--- /dev/null
+++ b/objectivec/google/protobuf/Any.pbobjc.h
@@ -0,0 +1,100 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: google/protobuf/any.proto
+
+#import "GPBProtocolBuffers.h"
+
+#if GOOGLE_PROTOBUF_OBJC_GEN_VERSION != 30000
+#error This file was generated by a different version of protoc-gen-objc which is incompatible with your Protocol Buffer sources.
+#endif
+
+// @@protoc_insertion_point(imports)
+
+CF_EXTERN_C_BEGIN
+
+
+#pragma mark - GPBAnyRoot
+
+@interface GPBAnyRoot : GPBRootObject
+
+// The base class provides:
+//   + (GPBExtensionRegistry *)extensionRegistry;
+// which is an GPBExtensionRegistry that includes all the extensions defined by
+// this file and all files that it depends on.
+
+@end
+
+#pragma mark - GPBAny
+
+typedef GPB_ENUM(GPBAny_FieldNumber) {
+  GPBAny_FieldNumber_TypeURL = 1,
+  GPBAny_FieldNumber_Value = 2,
+};
+
+// `Any` contains an arbitrary serialized message along with a URL
+// that describes the type of the serialized message.
+//
+// The proto runtimes and/or compiler will eventually
+//  provide utilities to pack/unpack Any values (projected Q1/15).
+//
+// # JSON
+// The JSON representation of an `Any` value uses the regular
+// representation of the deserialized, embedded message, with an
+// additional field `@type` which contains the type URL. Example:
+//
+//     package google.profile;
+//     message Person {
+//       string first_name = 1;
+//       string last_name = 2;
+//     }
+//
+//     {
+//       "@type": "type.googleapis.com/google.profile.Person",
+//       "firstName": <string>,
+//       "lastName": <string>
+//     }
+//
+// If the embedded message type is well-known and has a custom JSON
+// representation, that representation will be embedded adding a field
+// `value` which holds the custom JSON in addition to the the `@type`
+// field. Example (for message [google.protobuf.Duration][google.protobuf.Duration]):
+//
+//     {
+//       "@type": "type.googleapis.com/google.protobuf.Duration",
+//       "value": "1.212s"
+//     }
+@interface GPBAny : GPBMessage
+
+// A URL/resource name whose content describes the type of the
+// serialized message.
+//
+// For URLs which use the schema `http`, `https`, or no schema, the
+// following restrictions and interpretations apply:
+//
+// * If no schema is provided, `https` is assumed.
+// * The last segment of the URL's path must represent the fully
+//   qualified name of the type (as in `path/google.protobuf.Duration`).
+// * An HTTP GET on the URL must yield a [google.protobuf.Type][google.protobuf.Type]
+//   value in binary format, or produce an error.
+// * Applications are allowed to cache lookup results based on the
+//   URL, or have them precompiled into a binary to avoid any
+//   lookup. Therefore, binary compatibility needs to be preserved
+//   on changes to types. (Use versioned type names to manage
+//   breaking changes.)
+//
+// Schemas other than `http`, `https` (or the empty schema) might be
+// used with implementation specific semantics.
+//
+// Types originating from the `google.*` package
+// namespace should use `type.googleapis.com/full.type.name` (without
+// schema and path). A type service will eventually become available which
+// serves those URLs (projected Q2/15).
+@property(nonatomic, readwrite, copy) NSString *typeURL;
+
+// Must be valid serialized data of the above specified type.
+@property(nonatomic, readwrite, copy) NSData *value;
+
+@end
+
+CF_EXTERN_C_END
+
+// @@protoc_insertion_point(global_scope)
diff --git a/objectivec/google/protobuf/Any.pbobjc.m b/objectivec/google/protobuf/Any.pbobjc.m
new file mode 100644
index 00000000..4db73cb9
--- /dev/null
+++ b/objectivec/google/protobuf/Any.pbobjc.m
@@ -0,0 +1,93 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: google/protobuf/any.proto
+
+#import "GPBProtocolBuffers_RuntimeSupport.h"
+#import "google/protobuf/Any.pbobjc.h"
+// @@protoc_insertion_point(imports)
+
+#pragma mark - GPBAnyRoot
+
+@implementation GPBAnyRoot
+
+@end
+
+static GPBFileDescriptor *GPBAnyRoot_FileDescriptor(void) {
+  // This is called by +initialize so there is no need to worry
+  // about thread safety of the singleton.
+  static GPBFileDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    descriptor = [[GPBFileDescriptor alloc] initWithPackage:@"google.protobuf"
+                                                     syntax:GPBFileSyntaxProto3];
+  }
+  return descriptor;
+}
+
+#pragma mark - GPBAny
+
+@implementation GPBAny
+
+@dynamic typeURL;
+@dynamic value;
+
+typedef struct GPBAny_Storage {
+  uint32_t _has_storage_[1];
+  NSString *typeURL;
+  NSData *value;
+} GPBAny_Storage;
+
+// This method is threadsafe because it is initially called
+// in +initialize for each subclass.
++ (GPBDescriptor *)descriptor {
+  static GPBDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    static GPBMessageFieldDescription fields[] = {
+      {
+        .name = "typeURL",
+        .number = GPBAny_FieldNumber_TypeURL,
+        .hasIndex = 0,
+        .flags = GPBFieldOptional | GPBFieldTextFormatNameCustom,
+        .type = GPBTypeString,
+        .offset = offsetof(GPBAny_Storage, typeURL),
+        .defaultValue.valueString = nil,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+      {
+        .name = "value",
+        .number = GPBAny_FieldNumber_Value,
+        .hasIndex = 1,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeData,
+        .offset = offsetof(GPBAny_Storage, value),
+        .defaultValue.valueData = nil,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+    };
+#if GPBOBJC_SKIP_MESSAGE_TEXTFORMAT_EXTRAS
+    const char *extraTextFormatInfo = NULL;
+#else
+    static const char *extraTextFormatInfo = "\001\001\004\241!!\000";
+#endif  // GPBOBJC_SKIP_MESSAGE_TEXTFORMAT_EXTRAS
+    descriptor = [GPBDescriptor allocDescriptorForClass:[GPBAny class]
+                                              rootClass:[GPBAnyRoot class]
+                                                   file:GPBAnyRoot_FileDescriptor()
+                                                 fields:fields
+                                             fieldCount:sizeof(fields) / sizeof(GPBMessageFieldDescription)
+                                                 oneofs:NULL
+                                             oneofCount:0
+                                                  enums:NULL
+                                              enumCount:0
+                                                 ranges:NULL
+                                             rangeCount:0
+                                            storageSize:sizeof(GPBAny_Storage)
+                                             wireFormat:NO
+                                    extraTextFormatInfo:extraTextFormatInfo];
+  }
+  return descriptor;
+}
+
+@end
+
+
+// @@protoc_insertion_point(global_scope)
diff --git a/objectivec/google/protobuf/Api.pbobjc.h b/objectivec/google/protobuf/Api.pbobjc.h
new file mode 100644
index 00000000..9e6fc850
--- /dev/null
+++ b/objectivec/google/protobuf/Api.pbobjc.h
@@ -0,0 +1,121 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: google/protobuf/api.proto
+
+#import "GPBProtocolBuffers.h"
+
+#if GOOGLE_PROTOBUF_OBJC_GEN_VERSION != 30000
+#error This file was generated by a different version of protoc-gen-objc which is incompatible with your Protocol Buffer sources.
+#endif
+
+// @@protoc_insertion_point(imports)
+
+CF_EXTERN_C_BEGIN
+
+@class GPBSourceContext;
+
+
+#pragma mark - GPBApiRoot
+
+@interface GPBApiRoot : GPBRootObject
+
+// The base class provides:
+//   + (GPBExtensionRegistry *)extensionRegistry;
+// which is an GPBExtensionRegistry that includes all the extensions defined by
+// this file and all files that it depends on.
+
+@end
+
+#pragma mark - GPBApi
+
+typedef GPB_ENUM(GPBApi_FieldNumber) {
+  GPBApi_FieldNumber_Name = 1,
+  GPBApi_FieldNumber_MethodsArray = 2,
+  GPBApi_FieldNumber_OptionsArray = 3,
+  GPBApi_FieldNumber_Version = 4,
+  GPBApi_FieldNumber_SourceContext = 5,
+};
+
+// Api is a light-weight descriptor for a protocol buffer service.
+@interface GPBApi : GPBMessage
+
+// The fully qualified name of this api, including package name
+// followed by the api's simple name.
+@property(nonatomic, readwrite, copy) NSString *name;
+
+// The methods of this api, in unspecified order.
+// |methodsArray| contains |GPBMethod|
+@property(nonatomic, readwrite, strong) NSMutableArray *methodsArray;
+
+// Any metadata attached to the API.
+// |optionsArray| contains |GPBOption|
+@property(nonatomic, readwrite, strong) NSMutableArray *optionsArray;
+
+// A version string for this api. If specified, must have the form
+// `major-version.minor-version`, as in `1.10`. If the minor version
+// is omitted, it defaults to zero. If the entire version field is
+// empty, the major version is derived from the package name, as
+// outlined below. If the field is not empty, the version in the
+// package name will be verified to be consistent with what is
+// provided here.
+//
+// The versioning schema uses [semantic
+// versioning](http://semver.org) where the major version number
+// indicates a breaking change and the minor version an additive,
+// non-breaking change. Both version numbers are signals to users
+// what to expect from different versions, and should be carefully
+// chosen based on the product plan.
+//
+// The major version is also reflected in the package name of the
+// API, which must end in `v<major-version>`, as in
+// `google.feature.v1`. For major versions 0 and 1, the suffix can
+// be omitted. Zero major versions must only be used for
+// experimental, none-GA apis.
+//
+// See also: [design doc](http://go/api-versioning).
+@property(nonatomic, readwrite, copy) NSString *version;
+
+// Source context for the protocol buffer service represented by this
+// message.
+@property(nonatomic, readwrite) BOOL hasSourceContext;
+@property(nonatomic, readwrite, strong) GPBSourceContext *sourceContext;
+
+@end
+
+#pragma mark - GPBMethod
+
+typedef GPB_ENUM(GPBMethod_FieldNumber) {
+  GPBMethod_FieldNumber_Name = 1,
+  GPBMethod_FieldNumber_RequestTypeURL = 2,
+  GPBMethod_FieldNumber_RequestStreaming = 3,
+  GPBMethod_FieldNumber_ResponseTypeURL = 4,
+  GPBMethod_FieldNumber_ResponseStreaming = 5,
+  GPBMethod_FieldNumber_OptionsArray = 6,
+};
+
+// Method represents a method of an api.
+@interface GPBMethod : GPBMessage
+
+// The simple name of this method.
+@property(nonatomic, readwrite, copy) NSString *name;
+
+// A URL of the input message type.
+@property(nonatomic, readwrite, copy) NSString *requestTypeURL;
+
+// If true, the request is streamed.
+@property(nonatomic, readwrite) BOOL requestStreaming;
+
+// The URL of the output message type.
+@property(nonatomic, readwrite, copy) NSString *responseTypeURL;
+
+// If true, the response is streamed.
+@property(nonatomic, readwrite) BOOL responseStreaming;
+
+// Any metadata attached to the method.
+// |optionsArray| contains |GPBOption|
+@property(nonatomic, readwrite, strong) NSMutableArray *optionsArray;
+
+@end
+
+CF_EXTERN_C_END
+
+// @@protoc_insertion_point(global_scope)
diff --git a/objectivec/google/protobuf/Api.pbobjc.m b/objectivec/google/protobuf/Api.pbobjc.m
new file mode 100644
index 00000000..9416860a
--- /dev/null
+++ b/objectivec/google/protobuf/Api.pbobjc.m
@@ -0,0 +1,262 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: google/protobuf/api.proto
+
+#import "GPBProtocolBuffers_RuntimeSupport.h"
+#import "google/protobuf/Api.pbobjc.h"
+#import "google/protobuf/SourceContext.pbobjc.h"
+#import "google/protobuf/Type.pbobjc.h"
+// @@protoc_insertion_point(imports)
+
+#pragma mark - GPBApiRoot
+
+@implementation GPBApiRoot
+
++ (GPBExtensionRegistry*)extensionRegistry {
+  // This is called by +initialize so there is no need to worry
+  // about thread safety and initialization of registry.
+  static GPBExtensionRegistry* registry = nil;
+  if (!registry) {
+    registry = [[GPBExtensionRegistry alloc] init];
+    static GPBExtensionDescription descriptions[] = {
+    };
+    #pragma unused (descriptions)
+    [registry addExtensions:[GPBSourceContextRoot extensionRegistry]];
+    [registry addExtensions:[GPBTypeRoot extensionRegistry]];
+  }
+  return registry;
+}
+
+@end
+
+static GPBFileDescriptor *GPBApiRoot_FileDescriptor(void) {
+  // This is called by +initialize so there is no need to worry
+  // about thread safety of the singleton.
+  static GPBFileDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    descriptor = [[GPBFileDescriptor alloc] initWithPackage:@"google.protobuf"
+                                                     syntax:GPBFileSyntaxProto3];
+  }
+  return descriptor;
+}
+
+#pragma mark - GPBApi
+
+@implementation GPBApi
+
+@dynamic name;
+@dynamic methodsArray;
+@dynamic optionsArray;
+@dynamic version;
+@dynamic hasSourceContext, sourceContext;
+
+typedef struct GPBApi_Storage {
+  uint32_t _has_storage_[1];
+  NSString *name;
+  NSMutableArray *methodsArray;
+  NSMutableArray *optionsArray;
+  NSString *version;
+  GPBSourceContext *sourceContext;
+} GPBApi_Storage;
+
+// This method is threadsafe because it is initially called
+// in +initialize for each subclass.
++ (GPBDescriptor *)descriptor {
+  static GPBDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    static GPBMessageFieldDescription fields[] = {
+      {
+        .name = "name",
+        .number = GPBApi_FieldNumber_Name,
+        .hasIndex = 0,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeString,
+        .offset = offsetof(GPBApi_Storage, name),
+        .defaultValue.valueString = nil,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+      {
+        .name = "methodsArray",
+        .number = GPBApi_FieldNumber_MethodsArray,
+        .hasIndex = GPBNoHasBit,
+        .flags = GPBFieldRepeated,
+        .type = GPBTypeMessage,
+        .offset = offsetof(GPBApi_Storage, methodsArray),
+        .defaultValue.valueMessage = nil,
+        .typeSpecific.className = GPBStringifySymbol(GPBMethod),
+        .fieldOptions = NULL,
+      },
+      {
+        .name = "optionsArray",
+        .number = GPBApi_FieldNumber_OptionsArray,
+        .hasIndex = GPBNoHasBit,
+        .flags = GPBFieldRepeated,
+        .type = GPBTypeMessage,
+        .offset = offsetof(GPBApi_Storage, optionsArray),
+        .defaultValue.valueMessage = nil,
+        .typeSpecific.className = GPBStringifySymbol(GPBOption),
+        .fieldOptions = NULL,
+      },
+      {
+        .name = "version",
+        .number = GPBApi_FieldNumber_Version,
+        .hasIndex = 3,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeString,
+        .offset = offsetof(GPBApi_Storage, version),
+        .defaultValue.valueString = nil,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+      {
+        .name = "sourceContext",
+        .number = GPBApi_FieldNumber_SourceContext,
+        .hasIndex = 4,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeMessage,
+        .offset = offsetof(GPBApi_Storage, sourceContext),
+        .defaultValue.valueMessage = nil,
+        .typeSpecific.className = GPBStringifySymbol(GPBSourceContext),
+        .fieldOptions = NULL,
+      },
+    };
+    descriptor = [GPBDescriptor allocDescriptorForClass:[GPBApi class]
+                                              rootClass:[GPBApiRoot class]
+                                                   file:GPBApiRoot_FileDescriptor()
+                                                 fields:fields
+                                             fieldCount:sizeof(fields) / sizeof(GPBMessageFieldDescription)
+                                                 oneofs:NULL
+                                             oneofCount:0
+                                                  enums:NULL
+                                              enumCount:0
+                                                 ranges:NULL
+                                             rangeCount:0
+                                            storageSize:sizeof(GPBApi_Storage)
+                                             wireFormat:NO];
+  }
+  return descriptor;
+}
+
+@end
+
+#pragma mark - GPBMethod
+
+@implementation GPBMethod
+
+@dynamic name;
+@dynamic requestTypeURL;
+@dynamic requestStreaming;
+@dynamic responseTypeURL;
+@dynamic responseStreaming;
+@dynamic optionsArray;
+
+typedef struct GPBMethod_Storage {
+  uint32_t _has_storage_[1];
+  BOOL requestStreaming;
+  BOOL responseStreaming;
+  NSString *name;
+  NSString *requestTypeURL;
+  NSString *responseTypeURL;
+  NSMutableArray *optionsArray;
+} GPBMethod_Storage;
+
+// This method is threadsafe because it is initially called
+// in +initialize for each subclass.
++ (GPBDescriptor *)descriptor {
+  static GPBDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    static GPBMessageFieldDescription fields[] = {
+      {
+        .name = "name",
+        .number = GPBMethod_FieldNumber_Name,
+        .hasIndex = 0,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeString,
+        .offset = offsetof(GPBMethod_Storage, name),
+        .defaultValue.valueString = nil,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+      {
+        .name = "requestTypeURL",
+        .number = GPBMethod_FieldNumber_RequestTypeURL,
+        .hasIndex = 1,
+        .flags = GPBFieldOptional | GPBFieldTextFormatNameCustom,
+        .type = GPBTypeString,
+        .offset = offsetof(GPBMethod_Storage, requestTypeURL),
+        .defaultValue.valueString = nil,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+      {
+        .name = "requestStreaming",
+        .number = GPBMethod_FieldNumber_RequestStreaming,
+        .hasIndex = 2,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeBool,
+        .offset = offsetof(GPBMethod_Storage, requestStreaming),
+        .defaultValue.valueBool = NO,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+      {
+        .name = "responseTypeURL",
+        .number = GPBMethod_FieldNumber_ResponseTypeURL,
+        .hasIndex = 3,
+        .flags = GPBFieldOptional | GPBFieldTextFormatNameCustom,
+        .type = GPBTypeString,
+        .offset = offsetof(GPBMethod_Storage, responseTypeURL),
+        .defaultValue.valueString = nil,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+      {
+        .name = "responseStreaming",
+        .number = GPBMethod_FieldNumber_ResponseStreaming,
+        .hasIndex = 4,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeBool,
+        .offset = offsetof(GPBMethod_Storage, responseStreaming),
+        .defaultValue.valueBool = NO,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+      {
+        .name = "optionsArray",
+        .number = GPBMethod_FieldNumber_OptionsArray,
+        .hasIndex = GPBNoHasBit,
+        .flags = GPBFieldRepeated,
+        .type = GPBTypeMessage,
+        .offset = offsetof(GPBMethod_Storage, optionsArray),
+        .defaultValue.valueMessage = nil,
+        .typeSpecific.className = GPBStringifySymbol(GPBOption),
+        .fieldOptions = NULL,
+      },
+    };
+#if GPBOBJC_SKIP_MESSAGE_TEXTFORMAT_EXTRAS
+    const char *extraTextFormatInfo = NULL;
+#else
+    static const char *extraTextFormatInfo = "\002\002\007\244\241!!\000\004\010\244\241!!\000";
+#endif  // GPBOBJC_SKIP_MESSAGE_TEXTFORMAT_EXTRAS
+    descriptor = [GPBDescriptor allocDescriptorForClass:[GPBMethod class]
+                                              rootClass:[GPBApiRoot class]
+                                                   file:GPBApiRoot_FileDescriptor()
+                                                 fields:fields
+                                             fieldCount:sizeof(fields) / sizeof(GPBMessageFieldDescription)
+                                                 oneofs:NULL
+                                             oneofCount:0
+                                                  enums:NULL
+                                              enumCount:0
+                                                 ranges:NULL
+                                             rangeCount:0
+                                            storageSize:sizeof(GPBMethod_Storage)
+                                             wireFormat:NO
+                                    extraTextFormatInfo:extraTextFormatInfo];
+  }
+  return descriptor;
+}
+
+@end
+
+
+// @@protoc_insertion_point(global_scope)
diff --git a/objectivec/google/protobuf/Descriptor.pbobjc.h b/objectivec/google/protobuf/Descriptor.pbobjc.h
index e3dacf25..19a82fd1 100644
--- a/objectivec/google/protobuf/Descriptor.pbobjc.h
+++ b/objectivec/google/protobuf/Descriptor.pbobjc.h
@@ -7,29 +7,18 @@
 #error This file was generated by a different version of protoc-gen-objc which is incompatible with your Protocol Buffer sources.
 #endif
 
+// @@protoc_insertion_point(imports)
+
 CF_EXTERN_C_BEGIN
 
-@class GPBDescriptorProto;
-@class GPBDescriptorProto_ExtensionRange;
-@class GPBEnumDescriptorProto;
 @class GPBEnumOptions;
-@class GPBEnumValueDescriptorProto;
 @class GPBEnumValueOptions;
-@class GPBFieldDescriptorProto;
 @class GPBFieldOptions;
-@class GPBFileDescriptorProto;
-@class GPBFileDescriptorSet;
 @class GPBFileOptions;
 @class GPBMessageOptions;
-@class GPBMethodDescriptorProto;
 @class GPBMethodOptions;
-@class GPBOneofDescriptorProto;
-@class GPBServiceDescriptorProto;
 @class GPBServiceOptions;
 @class GPBSourceCodeInfo;
-@class GPBSourceCodeInfo_Location;
-@class GPBUninterpretedOption;
-@class GPBUninterpretedOption_NamePart;
 
 #pragma mark - Enum GPBFieldDescriptorProto_Type
 
@@ -126,6 +115,12 @@ BOOL GPBFieldOptions_CType_IsValidValue(int32_t value);
 #pragma mark - GPBDescriptorRoot
 
 @interface GPBDescriptorRoot : GPBRootObject
+
+// The base class provides:
+//   + (GPBExtensionRegistry *)extensionRegistry;
+// which is an GPBExtensionRegistry that includes all the extensions defined by
+// this file and all files that it depends on.
+
 @end
 
 #pragma mark - GPBFileDescriptorSet
@@ -1049,3 +1044,5 @@ typedef GPB_ENUM(GPBSourceCodeInfo_Location_FieldNumber) {
 @end
 
 CF_EXTERN_C_END
+
+// @@protoc_insertion_point(global_scope)
diff --git a/objectivec/google/protobuf/Descriptor.pbobjc.m b/objectivec/google/protobuf/Descriptor.pbobjc.m
index 25e4cc73..2fc1953c 100644
--- a/objectivec/google/protobuf/Descriptor.pbobjc.m
+++ b/objectivec/google/protobuf/Descriptor.pbobjc.m
@@ -2,8 +2,8 @@
 // source: google/protobuf/descriptor.proto
 
 #import "GPBProtocolBuffers_RuntimeSupport.h"
-
 #import "google/protobuf/Descriptor.pbobjc.h"
+// @@protoc_insertion_point(imports)
 
 #pragma mark - GPBDescriptorRoot
 
@@ -2216,3 +2216,5 @@ typedef struct GPBSourceCodeInfo_Location_Storage {
 
 @end
 
+
+// @@protoc_insertion_point(global_scope)
diff --git a/objectivec/google/protobuf/Duration.pbobjc.h b/objectivec/google/protobuf/Duration.pbobjc.h
index c452d0bb..f65df6c9 100644
--- a/objectivec/google/protobuf/Duration.pbobjc.h
+++ b/objectivec/google/protobuf/Duration.pbobjc.h
@@ -7,14 +7,20 @@
 #error This file was generated by a different version of protoc-gen-objc which is incompatible with your Protocol Buffer sources.
 #endif
 
-CF_EXTERN_C_BEGIN
+// @@protoc_insertion_point(imports)
 
-@class GPBDuration;
+CF_EXTERN_C_BEGIN
 
 
 #pragma mark - GPBDurationRoot
 
 @interface GPBDurationRoot : GPBRootObject
+
+// The base class provides:
+//   + (GPBExtensionRegistry *)extensionRegistry;
+// which is an GPBExtensionRegistry that includes all the extensions defined by
+// this file and all files that it depends on.
+
 @end
 
 #pragma mark - GPBDuration
@@ -81,3 +87,5 @@ typedef GPB_ENUM(GPBDuration_FieldNumber) {
 @end
 
 CF_EXTERN_C_END
+
+// @@protoc_insertion_point(global_scope)
diff --git a/objectivec/google/protobuf/Duration.pbobjc.m b/objectivec/google/protobuf/Duration.pbobjc.m
index cf0a3064..4db030f4 100644
--- a/objectivec/google/protobuf/Duration.pbobjc.m
+++ b/objectivec/google/protobuf/Duration.pbobjc.m
@@ -2,8 +2,8 @@
 // source: google/protobuf/duration.proto
 
 #import "GPBProtocolBuffers_RuntimeSupport.h"
-
 #import "google/protobuf/Duration.pbobjc.h"
+// @@protoc_insertion_point(imports)
 
 #pragma mark - GPBDurationRoot
 
@@ -83,3 +83,5 @@ typedef struct GPBDuration_Storage {
 
 @end
 
+
+// @@protoc_insertion_point(global_scope)
diff --git a/objectivec/google/protobuf/Empty.pbobjc.h b/objectivec/google/protobuf/Empty.pbobjc.h
new file mode 100644
index 00000000..1356c3a7
--- /dev/null
+++ b/objectivec/google/protobuf/Empty.pbobjc.h
@@ -0,0 +1,41 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: google/protobuf/empty.proto
+
+#import "GPBProtocolBuffers.h"
+
+#if GOOGLE_PROTOBUF_OBJC_GEN_VERSION != 30000
+#error This file was generated by a different version of protoc-gen-objc which is incompatible with your Protocol Buffer sources.
+#endif
+
+// @@protoc_insertion_point(imports)
+
+CF_EXTERN_C_BEGIN
+
+
+#pragma mark - GPBEmptyRoot
+
+@interface GPBEmptyRoot : GPBRootObject
+
+// The base class provides:
+//   + (GPBExtensionRegistry *)extensionRegistry;
+// which is an GPBExtensionRegistry that includes all the extensions defined by
+// this file and all files that it depends on.
+
+@end
+
+#pragma mark - GPBEmpty
+
+// A generic empty message that you can re-use to avoid defining duplicated
+// empty messages in your APIs. A typical example is to use it as the request
+// or the response type of an API method. For instance:
+//
+//     service Foo {
+//       rpc Bar(google.protobuf.Empty) returns (google.protobuf.Empty);
+//     }
+@interface GPBEmpty : GPBMessage
+
+@end
+
+CF_EXTERN_C_END
+
+// @@protoc_insertion_point(global_scope)
diff --git a/objectivec/google/protobuf/Empty.pbobjc.m b/objectivec/google/protobuf/Empty.pbobjc.m
new file mode 100644
index 00000000..619fe905
--- /dev/null
+++ b/objectivec/google/protobuf/Empty.pbobjc.m
@@ -0,0 +1,61 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: google/protobuf/empty.proto
+
+#import "GPBProtocolBuffers_RuntimeSupport.h"
+#import "google/protobuf/Empty.pbobjc.h"
+// @@protoc_insertion_point(imports)
+
+#pragma mark - GPBEmptyRoot
+
+@implementation GPBEmptyRoot
+
+@end
+
+static GPBFileDescriptor *GPBEmptyRoot_FileDescriptor(void) {
+  // This is called by +initialize so there is no need to worry
+  // about thread safety of the singleton.
+  static GPBFileDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    descriptor = [[GPBFileDescriptor alloc] initWithPackage:@"google.protobuf"
+                                                     syntax:GPBFileSyntaxProto3];
+  }
+  return descriptor;
+}
+
+#pragma mark - GPBEmpty
+
+@implementation GPBEmpty
+
+
+typedef struct GPBEmpty_Storage {
+  uint32_t _has_storage_[0];
+} GPBEmpty_Storage;
+
+// This method is threadsafe because it is initially called
+// in +initialize for each subclass.
++ (GPBDescriptor *)descriptor {
+  static GPBDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    static GPBMessageFieldDescription fields[] = {
+    };
+    descriptor = [GPBDescriptor allocDescriptorForClass:[GPBEmpty class]
+                                              rootClass:[GPBEmptyRoot class]
+                                                   file:GPBEmptyRoot_FileDescriptor()
+                                                 fields:fields
+                                             fieldCount:sizeof(fields) / sizeof(GPBMessageFieldDescription)
+                                                 oneofs:NULL
+                                             oneofCount:0
+                                                  enums:NULL
+                                              enumCount:0
+                                                 ranges:NULL
+                                             rangeCount:0
+                                            storageSize:sizeof(GPBEmpty_Storage)
+                                             wireFormat:NO];
+  }
+  return descriptor;
+}
+
+@end
+
+
+// @@protoc_insertion_point(global_scope)
diff --git a/objectivec/google/protobuf/FieldMask.pbobjc.h b/objectivec/google/protobuf/FieldMask.pbobjc.h
new file mode 100644
index 00000000..ac6f03d2
--- /dev/null
+++ b/objectivec/google/protobuf/FieldMask.pbobjc.h
@@ -0,0 +1,160 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: google/protobuf/field_mask.proto
+
+#import "GPBProtocolBuffers.h"
+
+#if GOOGLE_PROTOBUF_OBJC_GEN_VERSION != 30000
+#error This file was generated by a different version of protoc-gen-objc which is incompatible with your Protocol Buffer sources.
+#endif
+
+// @@protoc_insertion_point(imports)
+
+CF_EXTERN_C_BEGIN
+
+
+#pragma mark - GPBFieldMaskRoot
+
+@interface GPBFieldMaskRoot : GPBRootObject
+
+// The base class provides:
+//   + (GPBExtensionRegistry *)extensionRegistry;
+// which is an GPBExtensionRegistry that includes all the extensions defined by
+// this file and all files that it depends on.
+
+@end
+
+#pragma mark - GPBFieldMask
+
+typedef GPB_ENUM(GPBFieldMask_FieldNumber) {
+  GPBFieldMask_FieldNumber_PathsArray = 1,
+};
+
+// `FieldMask` represents a set of symbolic field paths, for example:
+//
+//     paths: "f.a"
+//     paths: "f.b.d"
+//
+// Here `f` represents a field in some root message, `a` and `b`
+// fields in the message found in `f`, and `d` a field found in the
+// message in `f.b`.
+//
+// Field masks are used to specify a subset of fields that should be
+// returned by a get operation or modified by an update operation.
+// Field masks also have a custom JSON encoding (see below).
+//
+// # Field Masks in Projections
+// When used in the context of a projection, a response message or
+// sub-message is filtered by the API to only contain those fields as
+// specified in the mask. For example, if the mask in the previous
+// example is applied to a response message as follows:
+//
+//     f {
+//       a : 22
+//       b {
+//         d : 1
+//         x : 2
+//       }
+//       y : 13
+//     }
+//     z: 8
+//
+// The result will not contain specific values for fields x,y and z
+// (there value will be set to the default, and omitted in proto text
+// output):
+//
+//
+//     f {
+//       a : 22
+//       b {
+//         d : 1
+//       }
+//     }
+//
+// A repeated field is not allowed except at the last position of a
+// field mask.
+//
+// If a FieldMask object is not present in a get operation, the
+// operation applies to all fields (as if a FieldMask of all fields
+// had been specified).
+//
+// Note that a field mask does not necessarily applies to the
+// top-level response message. In case of a REST get operation, the
+// field mask applies directly to the response, but in case of a REST
+// list operation, the mask instead applies to each individual message
+// in the returned resource list. In case of a REST custom method,
+// other definitions may be used. Where the mask applies will be
+// clearly documented together with its declaration in the API.  In
+// any case, the effect on the returned resource/resources is required
+// behavior for APIs.
+//
+// # Field Masks in Update Operations
+// A field mask in update operations specifies which fields of the
+// targeted resource are going to be updated. The API is required
+// to only change the values of the fields as specified in the mask
+// and leave the others untouched. If a resource is passed in to
+// describe the updated values, the API ignores the values of all
+// fields not covered by the mask.
+//
+// In order to reset a field's value to the default, the field must
+// be in the mask and set to the default value in the provided resource.
+// Hence, in order to reset all fields of a resource, provide a default
+// instance of the resource and set all fields in the mask, or do
+// not provide a mask as described below.
+//
+// If a field mask is not present on update, the operation applies to
+// all fields (as if a field mask of all fields has been specified).
+// Note that in the presence of schema evolution, this may mean that
+// fields the client does not know and has therefore not filled into
+// the request will be reset to their default. If this is unwanted
+// behavior, a specific service may require a client to always specify
+// a field mask, producing an error if not.
+//
+// As with get operations, the location of the resource which
+// describes the updated values in the request message depends on the
+// operation kind. In any case, the effect of the field mask is
+// required to be honored by the API.
+//
+// ## Considerations for HTTP REST
+// The HTTP kind of an update operation which uses a field mask must
+// be set to PATCH instead of PUT in order to satisfy HTTP semantics
+// (PUT must only be used for full updates).
+//
+// # JSON Encoding of Field Masks
+// In JSON, a field mask is encoded as a single string where paths are
+// separated by a comma. Fields name in each path are converted
+// to/from lower-camel naming conventions.
+//
+// As an example, consider the following message declarations:
+//
+//     message Profile {
+//       User user = 1;
+//       Photo photo = 2;
+//     }
+//     message User {
+//       string display_name = 1;
+//       string address = 2;
+//     }
+//
+// In proto a field mask for `Profile` may look as such:
+//
+//     mask {
+//       paths: "user.display_name"
+//       paths: "photo"
+//     }
+//
+// In JSON, the same mask is represented as below:
+//
+//     {
+//       mask: "user.displayName,photo"
+//     }
+@interface GPBFieldMask : GPBMessage
+
+// The set of field mask paths.
+// |pathsArray| contains |NSString|
+@property(nonatomic, readwrite, strong) NSMutableArray *pathsArray;
+
+@end
+
+CF_EXTERN_C_END
+
+// @@protoc_insertion_point(global_scope)
diff --git a/objectivec/google/protobuf/FieldMask.pbobjc.m b/objectivec/google/protobuf/FieldMask.pbobjc.m
new file mode 100644
index 00000000..e37ac6c2
--- /dev/null
+++ b/objectivec/google/protobuf/FieldMask.pbobjc.m
@@ -0,0 +1,74 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: google/protobuf/field_mask.proto
+
+#import "GPBProtocolBuffers_RuntimeSupport.h"
+#import "google/protobuf/FieldMask.pbobjc.h"
+// @@protoc_insertion_point(imports)
+
+#pragma mark - GPBFieldMaskRoot
+
+@implementation GPBFieldMaskRoot
+
+@end
+
+static GPBFileDescriptor *GPBFieldMaskRoot_FileDescriptor(void) {
+  // This is called by +initialize so there is no need to worry
+  // about thread safety of the singleton.
+  static GPBFileDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    descriptor = [[GPBFileDescriptor alloc] initWithPackage:@"google.protobuf"
+                                                     syntax:GPBFileSyntaxProto3];
+  }
+  return descriptor;
+}
+
+#pragma mark - GPBFieldMask
+
+@implementation GPBFieldMask
+
+@dynamic pathsArray;
+
+typedef struct GPBFieldMask_Storage {
+  uint32_t _has_storage_[1];
+  NSMutableArray *pathsArray;
+} GPBFieldMask_Storage;
+
+// This method is threadsafe because it is initially called
+// in +initialize for each subclass.
++ (GPBDescriptor *)descriptor {
+  static GPBDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    static GPBMessageFieldDescription fields[] = {
+      {
+        .name = "pathsArray",
+        .number = GPBFieldMask_FieldNumber_PathsArray,
+        .hasIndex = GPBNoHasBit,
+        .flags = GPBFieldRepeated,
+        .type = GPBTypeString,
+        .offset = offsetof(GPBFieldMask_Storage, pathsArray),
+        .defaultValue.valueMessage = nil,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+    };
+    descriptor = [GPBDescriptor allocDescriptorForClass:[GPBFieldMask class]
+                                              rootClass:[GPBFieldMaskRoot class]
+                                                   file:GPBFieldMaskRoot_FileDescriptor()
+                                                 fields:fields
+                                             fieldCount:sizeof(fields) / sizeof(GPBMessageFieldDescription)
+                                                 oneofs:NULL
+                                             oneofCount:0
+                                                  enums:NULL
+                                              enumCount:0
+                                                 ranges:NULL
+                                             rangeCount:0
+                                            storageSize:sizeof(GPBFieldMask_Storage)
+                                             wireFormat:NO];
+  }
+  return descriptor;
+}
+
+@end
+
+
+// @@protoc_insertion_point(global_scope)
diff --git a/objectivec/google/protobuf/SourceContext.pbobjc.h b/objectivec/google/protobuf/SourceContext.pbobjc.h
new file mode 100644
index 00000000..bcbf1e3d
--- /dev/null
+++ b/objectivec/google/protobuf/SourceContext.pbobjc.h
@@ -0,0 +1,44 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: google/protobuf/source_context.proto
+
+#import "GPBProtocolBuffers.h"
+
+#if GOOGLE_PROTOBUF_OBJC_GEN_VERSION != 30000
+#error This file was generated by a different version of protoc-gen-objc which is incompatible with your Protocol Buffer sources.
+#endif
+
+// @@protoc_insertion_point(imports)
+
+CF_EXTERN_C_BEGIN
+
+
+#pragma mark - GPBSourceContextRoot
+
+@interface GPBSourceContextRoot : GPBRootObject
+
+// The base class provides:
+//   + (GPBExtensionRegistry *)extensionRegistry;
+// which is an GPBExtensionRegistry that includes all the extensions defined by
+// this file and all files that it depends on.
+
+@end
+
+#pragma mark - GPBSourceContext
+
+typedef GPB_ENUM(GPBSourceContext_FieldNumber) {
+  GPBSourceContext_FieldNumber_FileName = 1,
+};
+
+// `SourceContext` represents information about the source of a
+// protobuf element, like the file in which it is defined.
+@interface GPBSourceContext : GPBMessage
+
+// The path-qualified name of the .proto file that contained the associated
+// protobuf element.  For example: `"google/protobuf/source.proto"`.
+@property(nonatomic, readwrite, copy) NSString *fileName;
+
+@end
+
+CF_EXTERN_C_END
+
+// @@protoc_insertion_point(global_scope)
diff --git a/objectivec/google/protobuf/SourceContext.pbobjc.m b/objectivec/google/protobuf/SourceContext.pbobjc.m
new file mode 100644
index 00000000..271f9243
--- /dev/null
+++ b/objectivec/google/protobuf/SourceContext.pbobjc.m
@@ -0,0 +1,74 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: google/protobuf/source_context.proto
+
+#import "GPBProtocolBuffers_RuntimeSupport.h"
+#import "google/protobuf/SourceContext.pbobjc.h"
+// @@protoc_insertion_point(imports)
+
+#pragma mark - GPBSourceContextRoot
+
+@implementation GPBSourceContextRoot
+
+@end
+
+static GPBFileDescriptor *GPBSourceContextRoot_FileDescriptor(void) {
+  // This is called by +initialize so there is no need to worry
+  // about thread safety of the singleton.
+  static GPBFileDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    descriptor = [[GPBFileDescriptor alloc] initWithPackage:@"google.protobuf"
+                                                     syntax:GPBFileSyntaxProto3];
+  }
+  return descriptor;
+}
+
+#pragma mark - GPBSourceContext
+
+@implementation GPBSourceContext
+
+@dynamic fileName;
+
+typedef struct GPBSourceContext_Storage {
+  uint32_t _has_storage_[1];
+  NSString *fileName;
+} GPBSourceContext_Storage;
+
+// This method is threadsafe because it is initially called
+// in +initialize for each subclass.
++ (GPBDescriptor *)descriptor {
+  static GPBDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    static GPBMessageFieldDescription fields[] = {
+      {
+        .name = "fileName",
+        .number = GPBSourceContext_FieldNumber_FileName,
+        .hasIndex = 0,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeString,
+        .offset = offsetof(GPBSourceContext_Storage, fileName),
+        .defaultValue.valueString = nil,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+    };
+    descriptor = [GPBDescriptor allocDescriptorForClass:[GPBSourceContext class]
+                                              rootClass:[GPBSourceContextRoot class]
+                                                   file:GPBSourceContextRoot_FileDescriptor()
+                                                 fields:fields
+                                             fieldCount:sizeof(fields) / sizeof(GPBMessageFieldDescription)
+                                                 oneofs:NULL
+                                             oneofCount:0
+                                                  enums:NULL
+                                              enumCount:0
+                                                 ranges:NULL
+                                             rangeCount:0
+                                            storageSize:sizeof(GPBSourceContext_Storage)
+                                             wireFormat:NO];
+  }
+  return descriptor;
+}
+
+@end
+
+
+// @@protoc_insertion_point(global_scope)
diff --git a/objectivec/google/protobuf/Struct.pbobjc.h b/objectivec/google/protobuf/Struct.pbobjc.h
new file mode 100644
index 00000000..f55af82b
--- /dev/null
+++ b/objectivec/google/protobuf/Struct.pbobjc.h
@@ -0,0 +1,134 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: google/protobuf/struct.proto
+
+#import "GPBProtocolBuffers.h"
+
+#if GOOGLE_PROTOBUF_OBJC_GEN_VERSION != 30000
+#error This file was generated by a different version of protoc-gen-objc which is incompatible with your Protocol Buffer sources.
+#endif
+
+// @@protoc_insertion_point(imports)
+
+CF_EXTERN_C_BEGIN
+
+@class GPBListValue;
+@class GPBStruct;
+
+#pragma mark - Enum GPBNullValue
+
+// `NullValue` is a singleton enumeration to represent the null
+// value for the `Value` type union.
+typedef GPB_ENUM(GPBNullValue) {
+  GPBNullValue_GPBUnrecognizedEnumeratorValue = kGPBUnrecognizedEnumeratorValue,
+  // Null value.
+  GPBNullValue_NullValue = 0,
+};
+
+GPBEnumDescriptor *GPBNullValue_EnumDescriptor(void);
+
+BOOL GPBNullValue_IsValidValue(int32_t value);
+
+
+#pragma mark - GPBStructRoot
+
+@interface GPBStructRoot : GPBRootObject
+
+// The base class provides:
+//   + (GPBExtensionRegistry *)extensionRegistry;
+// which is an GPBExtensionRegistry that includes all the extensions defined by
+// this file and all files that it depends on.
+
+@end
+
+#pragma mark - GPBStruct
+
+typedef GPB_ENUM(GPBStruct_FieldNumber) {
+  GPBStruct_FieldNumber_Fields = 1,
+};
+
+// `Struct` represents a structured data value, consisting of fields
+// which map to dynamically typed values. In some languages, `Struct`
+// might be supported by a native representation. For example, in
+// scripting languages like JS a struct is represented as an
+// object. The details of that representation are described together
+// with the proto support for the language.
+@interface GPBStruct : GPBMessage
+
+// Map of dynamically typed values.
+// |fields| values are |GPBValue|
+@property(nonatomic, readwrite, strong) NSMutableDictionary *fields;
+
+@end
+
+#pragma mark - GPBValue
+
+typedef GPB_ENUM(GPBValue_FieldNumber) {
+  GPBValue_FieldNumber_NullValue = 1,
+  GPBValue_FieldNumber_NumberValue = 2,
+  GPBValue_FieldNumber_StringValue = 3,
+  GPBValue_FieldNumber_BoolValue = 4,
+  GPBValue_FieldNumber_StructValue = 5,
+  GPBValue_FieldNumber_ListValue = 6,
+};
+
+typedef GPB_ENUM(GPBValue_Kind_OneOfCase) {
+  GPBValue_Kind_OneOfCase_GPBUnsetOneOfCase = 0,
+  GPBValue_Kind_OneOfCase_NullValue = 1,
+  GPBValue_Kind_OneOfCase_NumberValue = 2,
+  GPBValue_Kind_OneOfCase_StringValue = 3,
+  GPBValue_Kind_OneOfCase_BoolValue = 4,
+  GPBValue_Kind_OneOfCase_StructValue = 5,
+  GPBValue_Kind_OneOfCase_ListValue = 6,
+};
+
+// `Value` represents a dynamically typed value which can be either
+// null, a number, a string, a boolean, a recursive struct value, or a
+// list of values. A producer of value is expected to set one of that
+// variants, absence of any variant indicates an error.
+@interface GPBValue : GPBMessage
+
+@property(nonatomic, readonly) GPBValue_Kind_OneOfCase kindOneOfCase;
+
+// Represents a null value.
+@property(nonatomic, readwrite) GPBNullValue nullValue;
+
+// Represents a double value.
+@property(nonatomic, readwrite) double numberValue;
+
+// Represents a string value.
+@property(nonatomic, readwrite, copy) NSString *stringValue;
+
+// Represents a boolean value.
+@property(nonatomic, readwrite) BOOL boolValue;
+
+// Represents a structured value.
+@property(nonatomic, readwrite, strong) GPBStruct *structValue;
+
+// Represents a repeated `Value`.
+@property(nonatomic, readwrite, strong) GPBListValue *listValue;
+
+@end
+
+int32_t GPBValue_NullValue_RawValue(GPBValue *message);
+void SetGPBValue_NullValue_RawValue(GPBValue *message, int32_t value);
+
+void GPBValue_ClearKindOneOfCase(GPBValue *message);
+
+#pragma mark - GPBListValue
+
+typedef GPB_ENUM(GPBListValue_FieldNumber) {
+  GPBListValue_FieldNumber_ValuesArray = 1,
+};
+
+// `ListValue` is a wrapper around a repeated field of values.
+@interface GPBListValue : GPBMessage
+
+// Repeated field of dynamically typed values.
+// |valuesArray| contains |GPBValue|
+@property(nonatomic, readwrite, strong) NSMutableArray *valuesArray;
+
+@end
+
+CF_EXTERN_C_END
+
+// @@protoc_insertion_point(global_scope)
diff --git a/objectivec/google/protobuf/Struct.pbobjc.m b/objectivec/google/protobuf/Struct.pbobjc.m
new file mode 100644
index 00000000..e5a8b547
--- /dev/null
+++ b/objectivec/google/protobuf/Struct.pbobjc.m
@@ -0,0 +1,284 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: google/protobuf/struct.proto
+
+#import "GPBProtocolBuffers_RuntimeSupport.h"
+#import "google/protobuf/Struct.pbobjc.h"
+// @@protoc_insertion_point(imports)
+
+#pragma mark - GPBStructRoot
+
+@implementation GPBStructRoot
+
+@end
+
+static GPBFileDescriptor *GPBStructRoot_FileDescriptor(void) {
+  // This is called by +initialize so there is no need to worry
+  // about thread safety of the singleton.
+  static GPBFileDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    descriptor = [[GPBFileDescriptor alloc] initWithPackage:@"google.protobuf"
+                                                     syntax:GPBFileSyntaxProto3];
+  }
+  return descriptor;
+}
+
+#pragma mark - Enum GPBNullValue
+
+GPBEnumDescriptor *GPBNullValue_EnumDescriptor(void) {
+  static GPBEnumDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    static GPBMessageEnumValueDescription values[] = {
+      { .name = "NullValue", .number = GPBNullValue_NullValue },
+    };
+    descriptor = [GPBEnumDescriptor allocDescriptorForName:GPBNSStringifySymbol(GPBNullValue)
+                                                   values:values
+                                               valueCount:sizeof(values) / sizeof(GPBMessageEnumValueDescription)
+                                             enumVerifier:GPBNullValue_IsValidValue];
+  }
+  return descriptor;
+}
+
+BOOL GPBNullValue_IsValidValue(int32_t value__) {
+  switch (value__) {
+    case GPBNullValue_NullValue:
+      return YES;
+    default:
+      return NO;
+  }
+}
+
+#pragma mark - GPBStruct
+
+@implementation GPBStruct
+
+@dynamic fields;
+
+typedef struct GPBStruct_Storage {
+  uint32_t _has_storage_[1];
+  NSMutableDictionary *fields;
+} GPBStruct_Storage;
+
+// This method is threadsafe because it is initially called
+// in +initialize for each subclass.
++ (GPBDescriptor *)descriptor {
+  static GPBDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    static GPBMessageFieldDescription fields[] = {
+      {
+        .name = "fields",
+        .number = GPBStruct_FieldNumber_Fields,
+        .hasIndex = GPBNoHasBit,
+        .flags = GPBFieldMapKeyString,
+        .type = GPBTypeMessage,
+        .offset = offsetof(GPBStruct_Storage, fields),
+        .defaultValue.valueMessage = nil,
+        .typeSpecific.className = GPBStringifySymbol(GPBValue),
+        .fieldOptions = NULL,
+      },
+    };
+    descriptor = [GPBDescriptor allocDescriptorForClass:[GPBStruct class]
+                                              rootClass:[GPBStructRoot class]
+                                                   file:GPBStructRoot_FileDescriptor()
+                                                 fields:fields
+                                             fieldCount:sizeof(fields) / sizeof(GPBMessageFieldDescription)
+                                                 oneofs:NULL
+                                             oneofCount:0
+                                                  enums:NULL
+                                              enumCount:0
+                                                 ranges:NULL
+                                             rangeCount:0
+                                            storageSize:sizeof(GPBStruct_Storage)
+                                             wireFormat:NO];
+  }
+  return descriptor;
+}
+
+@end
+
+#pragma mark - GPBValue
+
+@implementation GPBValue
+
+@dynamic kindOneOfCase;
+@dynamic nullValue;
+@dynamic numberValue;
+@dynamic stringValue;
+@dynamic boolValue;
+@dynamic structValue;
+@dynamic listValue;
+
+typedef struct GPBValue_Storage {
+  uint32_t _has_storage_[2];
+  BOOL boolValue;
+  GPBNullValue nullValue;
+  NSString *stringValue;
+  GPBStruct *structValue;
+  GPBListValue *listValue;
+  double numberValue;
+} GPBValue_Storage;
+
+// This method is threadsafe because it is initially called
+// in +initialize for each subclass.
++ (GPBDescriptor *)descriptor {
+  static GPBDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    static GPBMessageOneofDescription oneofs[] = {
+      {
+        .name = "kind",
+        .index = -1,
+      },
+    };
+    static GPBMessageFieldDescription fields[] = {
+      {
+        .name = "nullValue",
+        .number = GPBValue_FieldNumber_NullValue,
+        .hasIndex = -1,
+        .flags = GPBFieldOptional | GPBFieldHasEnumDescriptor,
+        .type = GPBTypeEnum,
+        .offset = offsetof(GPBValue_Storage, nullValue),
+        .defaultValue.valueEnum = GPBNullValue_NullValue,
+        .typeSpecific.enumDescFunc = GPBNullValue_EnumDescriptor,
+        .fieldOptions = NULL,
+      },
+      {
+        .name = "numberValue",
+        .number = GPBValue_FieldNumber_NumberValue,
+        .hasIndex = -1,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeDouble,
+        .offset = offsetof(GPBValue_Storage, numberValue),
+        .defaultValue.valueDouble = 0,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+      {
+        .name = "stringValue",
+        .number = GPBValue_FieldNumber_StringValue,
+        .hasIndex = -1,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeString,
+        .offset = offsetof(GPBValue_Storage, stringValue),
+        .defaultValue.valueString = nil,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+      {
+        .name = "boolValue",
+        .number = GPBValue_FieldNumber_BoolValue,
+        .hasIndex = -1,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeBool,
+        .offset = offsetof(GPBValue_Storage, boolValue),
+        .defaultValue.valueBool = NO,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+      {
+        .name = "structValue",
+        .number = GPBValue_FieldNumber_StructValue,
+        .hasIndex = -1,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeMessage,
+        .offset = offsetof(GPBValue_Storage, structValue),
+        .defaultValue.valueMessage = nil,
+        .typeSpecific.className = GPBStringifySymbol(GPBStruct),
+        .fieldOptions = NULL,
+      },
+      {
+        .name = "listValue",
+        .number = GPBValue_FieldNumber_ListValue,
+        .hasIndex = -1,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeMessage,
+        .offset = offsetof(GPBValue_Storage, listValue),
+        .defaultValue.valueMessage = nil,
+        .typeSpecific.className = GPBStringifySymbol(GPBListValue),
+        .fieldOptions = NULL,
+      },
+    };
+    descriptor = [GPBDescriptor allocDescriptorForClass:[GPBValue class]
+                                              rootClass:[GPBStructRoot class]
+                                                   file:GPBStructRoot_FileDescriptor()
+                                                 fields:fields
+                                             fieldCount:sizeof(fields) / sizeof(GPBMessageFieldDescription)
+                                                 oneofs:oneofs
+                                             oneofCount:sizeof(oneofs) / sizeof(GPBMessageOneofDescription)
+                                                  enums:NULL
+                                              enumCount:0
+                                                 ranges:NULL
+                                             rangeCount:0
+                                            storageSize:sizeof(GPBValue_Storage)
+                                             wireFormat:NO];
+  }
+  return descriptor;
+}
+
+@end
+
+int32_t GPBValue_NullValue_RawValue(GPBValue *message) {
+  GPBDescriptor *descriptor = [GPBValue descriptor];
+  GPBFieldDescriptor *field = [descriptor fieldWithNumber:GPBValue_FieldNumber_NullValue];
+  return GPBGetInt32IvarWithField(message, field);
+}
+
+void SetGPBValue_NullValue_RawValue(GPBValue *message, int32_t value) {
+  GPBDescriptor *descriptor = [GPBValue descriptor];
+  GPBFieldDescriptor *field = [descriptor fieldWithNumber:GPBValue_FieldNumber_NullValue];
+  GPBSetInt32IvarWithFieldInternal(message, field, value, descriptor.file.syntax);
+}
+
+void GPBValue_ClearKindOneOfCase(GPBValue *message) {
+  GPBDescriptor *descriptor = [message descriptor];
+  GPBOneofDescriptor *oneof = descriptor->oneofs_[0];
+  GPBMaybeClearOneof(message, oneof, 0);
+}
+#pragma mark - GPBListValue
+
+@implementation GPBListValue
+
+@dynamic valuesArray;
+
+typedef struct GPBListValue_Storage {
+  uint32_t _has_storage_[1];
+  NSMutableArray *valuesArray;
+} GPBListValue_Storage;
+
+// This method is threadsafe because it is initially called
+// in +initialize for each subclass.
++ (GPBDescriptor *)descriptor {
+  static GPBDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    static GPBMessageFieldDescription fields[] = {
+      {
+        .name = "valuesArray",
+        .number = GPBListValue_FieldNumber_ValuesArray,
+        .hasIndex = GPBNoHasBit,
+        .flags = GPBFieldRepeated,
+        .type = GPBTypeMessage,
+        .offset = offsetof(GPBListValue_Storage, valuesArray),
+        .defaultValue.valueMessage = nil,
+        .typeSpecific.className = GPBStringifySymbol(GPBValue),
+        .fieldOptions = NULL,
+      },
+    };
+    descriptor = [GPBDescriptor allocDescriptorForClass:[GPBListValue class]
+                                              rootClass:[GPBStructRoot class]
+                                                   file:GPBStructRoot_FileDescriptor()
+                                                 fields:fields
+                                             fieldCount:sizeof(fields) / sizeof(GPBMessageFieldDescription)
+                                                 oneofs:NULL
+                                             oneofCount:0
+                                                  enums:NULL
+                                              enumCount:0
+                                                 ranges:NULL
+                                             rangeCount:0
+                                            storageSize:sizeof(GPBListValue_Storage)
+                                             wireFormat:NO];
+  }
+  return descriptor;
+}
+
+@end
+
+
+// @@protoc_insertion_point(global_scope)
diff --git a/objectivec/google/protobuf/Timestamp.pbobjc.h b/objectivec/google/protobuf/Timestamp.pbobjc.h
index c9fc9175..a81321b4 100644
--- a/objectivec/google/protobuf/Timestamp.pbobjc.h
+++ b/objectivec/google/protobuf/Timestamp.pbobjc.h
@@ -7,14 +7,20 @@
 #error This file was generated by a different version of protoc-gen-objc which is incompatible with your Protocol Buffer sources.
 #endif
 
-CF_EXTERN_C_BEGIN
+// @@protoc_insertion_point(imports)
 
-@class GPBTimestamp;
+CF_EXTERN_C_BEGIN
 
 
 #pragma mark - GPBTimestampRoot
 
 @interface GPBTimestampRoot : GPBRootObject
+
+// The base class provides:
+//   + (GPBExtensionRegistry *)extensionRegistry;
+// which is an GPBExtensionRegistry that includes all the extensions defined by
+// this file and all files that it depends on.
+
 @end
 
 #pragma mark - GPBTimestamp
@@ -92,3 +98,5 @@ typedef GPB_ENUM(GPBTimestamp_FieldNumber) {
 @end
 
 CF_EXTERN_C_END
+
+// @@protoc_insertion_point(global_scope)
diff --git a/objectivec/google/protobuf/Timestamp.pbobjc.m b/objectivec/google/protobuf/Timestamp.pbobjc.m
index 1c8d3c76..197dff48 100644
--- a/objectivec/google/protobuf/Timestamp.pbobjc.m
+++ b/objectivec/google/protobuf/Timestamp.pbobjc.m
@@ -2,8 +2,8 @@
 // source: google/protobuf/timestamp.proto
 
 #import "GPBProtocolBuffers_RuntimeSupport.h"
-
 #import "google/protobuf/Timestamp.pbobjc.h"
+// @@protoc_insertion_point(imports)
 
 #pragma mark - GPBTimestampRoot
 
@@ -83,3 +83,5 @@ typedef struct GPBTimestamp_Storage {
 
 @end
 
+
+// @@protoc_insertion_point(global_scope)
diff --git a/objectivec/google/protobuf/Type.pbobjc.h b/objectivec/google/protobuf/Type.pbobjc.h
new file mode 100644
index 00000000..652a33a7
--- /dev/null
+++ b/objectivec/google/protobuf/Type.pbobjc.h
@@ -0,0 +1,274 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: google/protobuf/type.proto
+
+#import "GPBProtocolBuffers.h"
+
+#if GOOGLE_PROTOBUF_OBJC_GEN_VERSION != 30000
+#error This file was generated by a different version of protoc-gen-objc which is incompatible with your Protocol Buffer sources.
+#endif
+
+// @@protoc_insertion_point(imports)
+
+CF_EXTERN_C_BEGIN
+
+@class GPBAny;
+@class GPBSourceContext;
+
+#pragma mark - Enum GPBField_Kind
+
+// Kind represents a basic field type.
+typedef GPB_ENUM(GPBField_Kind) {
+  GPBField_Kind_GPBUnrecognizedEnumeratorValue = kGPBUnrecognizedEnumeratorValue,
+  // Field type unknown.
+  GPBField_Kind_TypeUnknown = 0,
+
+  // Field type double.
+  GPBField_Kind_TypeDouble = 1,
+
+  // Field type float.
+  GPBField_Kind_TypeFloat = 2,
+
+  // Field type int64.
+  GPBField_Kind_TypeInt64 = 3,
+
+  // Field type uint64.
+  GPBField_Kind_TypeUint64 = 4,
+
+  // Field type int32.
+  GPBField_Kind_TypeInt32 = 5,
+
+  // Field type fixed64.
+  GPBField_Kind_TypeFixed64 = 6,
+
+  // Field type fixed32.
+  GPBField_Kind_TypeFixed32 = 7,
+
+  // Field type bool.
+  GPBField_Kind_TypeBool = 8,
+
+  // Field type string.
+  GPBField_Kind_TypeString = 9,
+
+  // Field type message.
+  GPBField_Kind_TypeMessage = 11,
+
+  // Field type bytes.
+  GPBField_Kind_TypeBytes = 12,
+
+  // Field type uint32.
+  GPBField_Kind_TypeUint32 = 13,
+
+  // Field type enum.
+  GPBField_Kind_TypeEnum = 14,
+
+  // Field type sfixed32.
+  GPBField_Kind_TypeSfixed32 = 15,
+
+  // Field type sfixed64.
+  GPBField_Kind_TypeSfixed64 = 16,
+
+  // Field type sint32.
+  GPBField_Kind_TypeSint32 = 17,
+
+  // Field type sint64.
+  GPBField_Kind_TypeSint64 = 18,
+};
+
+GPBEnumDescriptor *GPBField_Kind_EnumDescriptor(void);
+
+BOOL GPBField_Kind_IsValidValue(int32_t value);
+
+#pragma mark - Enum GPBField_Cardinality
+
+// Cardinality represents whether a field is optional, required, or
+// repeated.
+typedef GPB_ENUM(GPBField_Cardinality) {
+  GPBField_Cardinality_GPBUnrecognizedEnumeratorValue = kGPBUnrecognizedEnumeratorValue,
+  // The field cardinality is unknown. Typically an error condition.
+  GPBField_Cardinality_CardinalityUnknown = 0,
+
+  // For optional fields.
+  GPBField_Cardinality_CardinalityOptional = 1,
+
+  // For required fields. Not used for proto3.
+  GPBField_Cardinality_CardinalityRequired = 2,
+
+  // For repeated fields.
+  GPBField_Cardinality_CardinalityRepeated = 3,
+};
+
+GPBEnumDescriptor *GPBField_Cardinality_EnumDescriptor(void);
+
+BOOL GPBField_Cardinality_IsValidValue(int32_t value);
+
+
+#pragma mark - GPBTypeRoot
+
+@interface GPBTypeRoot : GPBRootObject
+
+// The base class provides:
+//   + (GPBExtensionRegistry *)extensionRegistry;
+// which is an GPBExtensionRegistry that includes all the extensions defined by
+// this file and all files that it depends on.
+
+@end
+
+#pragma mark - GPBType
+
+typedef GPB_ENUM(GPBType_FieldNumber) {
+  GPBType_FieldNumber_Name = 1,
+  GPBType_FieldNumber_FieldsArray = 2,
+  GPBType_FieldNumber_OneofsArray = 3,
+  GPBType_FieldNumber_OptionsArray = 4,
+  GPBType_FieldNumber_SourceContext = 5,
+};
+
+// A light-weight descriptor for a proto message type.
+@interface GPBType : GPBMessage
+
+// The fully qualified message name.
+@property(nonatomic, readwrite, copy) NSString *name;
+
+// The list of fields.
+// |fieldsArray| contains |GPBField|
+@property(nonatomic, readwrite, strong) NSMutableArray *fieldsArray;
+
+// The list of oneof definitions.
+// The list of oneofs declared in this Type
+// |oneofsArray| contains |NSString|
+@property(nonatomic, readwrite, strong) NSMutableArray *oneofsArray;
+
+// The proto options.
+// |optionsArray| contains |GPBOption|
+@property(nonatomic, readwrite, strong) NSMutableArray *optionsArray;
+
+// The source context.
+@property(nonatomic, readwrite) BOOL hasSourceContext;
+@property(nonatomic, readwrite, strong) GPBSourceContext *sourceContext;
+
+@end
+
+#pragma mark - GPBField
+
+typedef GPB_ENUM(GPBField_FieldNumber) {
+  GPBField_FieldNumber_Kind = 1,
+  GPBField_FieldNumber_Cardinality = 2,
+  GPBField_FieldNumber_Number = 3,
+  GPBField_FieldNumber_Name = 4,
+  GPBField_FieldNumber_TypeURL = 6,
+  GPBField_FieldNumber_OneofIndex = 7,
+  GPBField_FieldNumber_Packed = 8,
+  GPBField_FieldNumber_OptionsArray = 9,
+};
+
+// Field represents a single field of a message type.
+@interface GPBField : GPBMessage
+
+// The field kind.
+@property(nonatomic, readwrite) GPBField_Kind kind;
+
+// The field cardinality, i.e. optional/required/repeated.
+@property(nonatomic, readwrite) GPBField_Cardinality cardinality;
+
+// The proto field number.
+@property(nonatomic, readwrite) int32_t number;
+
+// The field name.
+@property(nonatomic, readwrite, copy) NSString *name;
+
+// The type URL (without the scheme) when the type is MESSAGE or ENUM,
+// such as `type.googleapis.com/google.protobuf.Empty`.
+@property(nonatomic, readwrite, copy) NSString *typeURL;
+
+// Index in Type.oneofs. Starts at 1. Zero means no oneof mapping.
+@property(nonatomic, readwrite) int32_t oneofIndex;
+
+// Whether to use alternative packed wire representation.
+@property(nonatomic, readwrite) BOOL packed;
+
+// The proto options.
+// |optionsArray| contains |GPBOption|
+@property(nonatomic, readwrite, strong) NSMutableArray *optionsArray;
+
+@end
+
+int32_t GPBField_Kind_RawValue(GPBField *message);
+void SetGPBField_Kind_RawValue(GPBField *message, int32_t value);
+
+int32_t GPBField_Cardinality_RawValue(GPBField *message);
+void SetGPBField_Cardinality_RawValue(GPBField *message, int32_t value);
+
+#pragma mark - GPBEnum
+
+typedef GPB_ENUM(GPBEnum_FieldNumber) {
+  GPBEnum_FieldNumber_Name = 1,
+  GPBEnum_FieldNumber_EnumvalueArray = 2,
+  GPBEnum_FieldNumber_OptionsArray = 3,
+  GPBEnum_FieldNumber_SourceContext = 4,
+};
+
+// Enum type definition.
+@interface GPBEnum : GPBMessage
+
+// Enum type name.
+@property(nonatomic, readwrite, copy) NSString *name;
+
+// Enum value definitions.
+// |enumvalueArray| contains |GPBEnumValue|
+@property(nonatomic, readwrite, strong) NSMutableArray *enumvalueArray;
+
+// Proto options for the enum type.
+// |optionsArray| contains |GPBOption|
+@property(nonatomic, readwrite, strong) NSMutableArray *optionsArray;
+
+// The source context.
+@property(nonatomic, readwrite) BOOL hasSourceContext;
+@property(nonatomic, readwrite, strong) GPBSourceContext *sourceContext;
+
+@end
+
+#pragma mark - GPBEnumValue
+
+typedef GPB_ENUM(GPBEnumValue_FieldNumber) {
+  GPBEnumValue_FieldNumber_Name = 1,
+  GPBEnumValue_FieldNumber_Number = 2,
+  GPBEnumValue_FieldNumber_OptionsArray = 3,
+};
+
+// Enum value definition.
+@interface GPBEnumValue : GPBMessage
+
+// Enum value name.
+@property(nonatomic, readwrite, copy) NSString *name;
+
+// Enum value number.
+@property(nonatomic, readwrite) int32_t number;
+
+// Proto options for the enum value.
+// |optionsArray| contains |GPBOption|
+@property(nonatomic, readwrite, strong) NSMutableArray *optionsArray;
+
+@end
+
+#pragma mark - GPBOption
+
+typedef GPB_ENUM(GPBOption_FieldNumber) {
+  GPBOption_FieldNumber_Name = 1,
+  GPBOption_FieldNumber_Value = 2,
+};
+
+// Proto option attached to messages/fields/enums etc.
+@interface GPBOption : GPBMessage
+
+// Proto option name.
+@property(nonatomic, readwrite, copy) NSString *name;
+
+// Proto option value.
+@property(nonatomic, readwrite) BOOL hasValue;
+@property(nonatomic, readwrite, strong) GPBAny *value;
+
+@end
+
+CF_EXTERN_C_END
+
+// @@protoc_insertion_point(global_scope)
diff --git a/objectivec/google/protobuf/Type.pbobjc.m b/objectivec/google/protobuf/Type.pbobjc.m
new file mode 100644
index 00000000..182370c8
--- /dev/null
+++ b/objectivec/google/protobuf/Type.pbobjc.m
@@ -0,0 +1,628 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: google/protobuf/type.proto
+
+#import "GPBProtocolBuffers_RuntimeSupport.h"
+#import "google/protobuf/Type.pbobjc.h"
+#import "google/protobuf/Any.pbobjc.h"
+#import "google/protobuf/SourceContext.pbobjc.h"
+// @@protoc_insertion_point(imports)
+
+#pragma mark - GPBTypeRoot
+
+@implementation GPBTypeRoot
+
++ (GPBExtensionRegistry*)extensionRegistry {
+  // This is called by +initialize so there is no need to worry
+  // about thread safety and initialization of registry.
+  static GPBExtensionRegistry* registry = nil;
+  if (!registry) {
+    registry = [[GPBExtensionRegistry alloc] init];
+    static GPBExtensionDescription descriptions[] = {
+    };
+    #pragma unused (descriptions)
+    [registry addExtensions:[GPBAnyRoot extensionRegistry]];
+    [registry addExtensions:[GPBSourceContextRoot extensionRegistry]];
+  }
+  return registry;
+}
+
+@end
+
+static GPBFileDescriptor *GPBTypeRoot_FileDescriptor(void) {
+  // This is called by +initialize so there is no need to worry
+  // about thread safety of the singleton.
+  static GPBFileDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    descriptor = [[GPBFileDescriptor alloc] initWithPackage:@"google.protobuf"
+                                                     syntax:GPBFileSyntaxProto3];
+  }
+  return descriptor;
+}
+
+#pragma mark - GPBType
+
+@implementation GPBType
+
+@dynamic name;
+@dynamic fieldsArray;
+@dynamic oneofsArray;
+@dynamic optionsArray;
+@dynamic hasSourceContext, sourceContext;
+
+typedef struct GPBType_Storage {
+  uint32_t _has_storage_[1];
+  NSString *name;
+  NSMutableArray *fieldsArray;
+  NSMutableArray *oneofsArray;
+  NSMutableArray *optionsArray;
+  GPBSourceContext *sourceContext;
+} GPBType_Storage;
+
+// This method is threadsafe because it is initially called
+// in +initialize for each subclass.
++ (GPBDescriptor *)descriptor {
+  static GPBDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    static GPBMessageFieldDescription fields[] = {
+      {
+        .name = "name",
+        .number = GPBType_FieldNumber_Name,
+        .hasIndex = 0,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeString,
+        .offset = offsetof(GPBType_Storage, name),
+        .defaultValue.valueString = nil,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+      {
+        .name = "fieldsArray",
+        .number = GPBType_FieldNumber_FieldsArray,
+        .hasIndex = GPBNoHasBit,
+        .flags = GPBFieldRepeated,
+        .type = GPBTypeMessage,
+        .offset = offsetof(GPBType_Storage, fieldsArray),
+        .defaultValue.valueMessage = nil,
+        .typeSpecific.className = GPBStringifySymbol(GPBField),
+        .fieldOptions = NULL,
+      },
+      {
+        .name = "oneofsArray",
+        .number = GPBType_FieldNumber_OneofsArray,
+        .hasIndex = GPBNoHasBit,
+        .flags = GPBFieldRepeated,
+        .type = GPBTypeString,
+        .offset = offsetof(GPBType_Storage, oneofsArray),
+        .defaultValue.valueMessage = nil,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+      {
+        .name = "optionsArray",
+        .number = GPBType_FieldNumber_OptionsArray,
+        .hasIndex = GPBNoHasBit,
+        .flags = GPBFieldRepeated,
+        .type = GPBTypeMessage,
+        .offset = offsetof(GPBType_Storage, optionsArray),
+        .defaultValue.valueMessage = nil,
+        .typeSpecific.className = GPBStringifySymbol(GPBOption),
+        .fieldOptions = NULL,
+      },
+      {
+        .name = "sourceContext",
+        .number = GPBType_FieldNumber_SourceContext,
+        .hasIndex = 4,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeMessage,
+        .offset = offsetof(GPBType_Storage, sourceContext),
+        .defaultValue.valueMessage = nil,
+        .typeSpecific.className = GPBStringifySymbol(GPBSourceContext),
+        .fieldOptions = NULL,
+      },
+    };
+    descriptor = [GPBDescriptor allocDescriptorForClass:[GPBType class]
+                                              rootClass:[GPBTypeRoot class]
+                                                   file:GPBTypeRoot_FileDescriptor()
+                                                 fields:fields
+                                             fieldCount:sizeof(fields) / sizeof(GPBMessageFieldDescription)
+                                                 oneofs:NULL
+                                             oneofCount:0
+                                                  enums:NULL
+                                              enumCount:0
+                                                 ranges:NULL
+                                             rangeCount:0
+                                            storageSize:sizeof(GPBType_Storage)
+                                             wireFormat:NO];
+  }
+  return descriptor;
+}
+
+@end
+
+#pragma mark - GPBField
+
+@implementation GPBField
+
+@dynamic kind;
+@dynamic cardinality;
+@dynamic number;
+@dynamic name;
+@dynamic typeURL;
+@dynamic oneofIndex;
+@dynamic packed;
+@dynamic optionsArray;
+
+typedef struct GPBField_Storage {
+  uint32_t _has_storage_[1];
+  BOOL packed;
+  GPBField_Kind kind;
+  GPBField_Cardinality cardinality;
+  int32_t number;
+  int32_t oneofIndex;
+  NSString *name;
+  NSString *typeURL;
+  NSMutableArray *optionsArray;
+} GPBField_Storage;
+
+// This method is threadsafe because it is initially called
+// in +initialize for each subclass.
++ (GPBDescriptor *)descriptor {
+  static GPBDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    static GPBMessageFieldDescription fields[] = {
+      {
+        .name = "kind",
+        .number = GPBField_FieldNumber_Kind,
+        .hasIndex = 0,
+        .flags = GPBFieldOptional | GPBFieldHasEnumDescriptor,
+        .type = GPBTypeEnum,
+        .offset = offsetof(GPBField_Storage, kind),
+        .defaultValue.valueEnum = GPBField_Kind_TypeUnknown,
+        .typeSpecific.enumDescFunc = GPBField_Kind_EnumDescriptor,
+        .fieldOptions = NULL,
+      },
+      {
+        .name = "cardinality",
+        .number = GPBField_FieldNumber_Cardinality,
+        .hasIndex = 1,
+        .flags = GPBFieldOptional | GPBFieldHasEnumDescriptor,
+        .type = GPBTypeEnum,
+        .offset = offsetof(GPBField_Storage, cardinality),
+        .defaultValue.valueEnum = GPBField_Cardinality_CardinalityUnknown,
+        .typeSpecific.enumDescFunc = GPBField_Cardinality_EnumDescriptor,
+        .fieldOptions = NULL,
+      },
+      {
+        .name = "number",
+        .number = GPBField_FieldNumber_Number,
+        .hasIndex = 2,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeInt32,
+        .offset = offsetof(GPBField_Storage, number),
+        .defaultValue.valueInt32 = 0,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+      {
+        .name = "name",
+        .number = GPBField_FieldNumber_Name,
+        .hasIndex = 3,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeString,
+        .offset = offsetof(GPBField_Storage, name),
+        .defaultValue.valueString = nil,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+      {
+        .name = "typeURL",
+        .number = GPBField_FieldNumber_TypeURL,
+        .hasIndex = 4,
+        .flags = GPBFieldOptional | GPBFieldTextFormatNameCustom,
+        .type = GPBTypeString,
+        .offset = offsetof(GPBField_Storage, typeURL),
+        .defaultValue.valueString = nil,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+      {
+        .name = "oneofIndex",
+        .number = GPBField_FieldNumber_OneofIndex,
+        .hasIndex = 5,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeInt32,
+        .offset = offsetof(GPBField_Storage, oneofIndex),
+        .defaultValue.valueInt32 = 0,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+      {
+        .name = "packed",
+        .number = GPBField_FieldNumber_Packed,
+        .hasIndex = 6,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeBool,
+        .offset = offsetof(GPBField_Storage, packed),
+        .defaultValue.valueBool = NO,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+      {
+        .name = "optionsArray",
+        .number = GPBField_FieldNumber_OptionsArray,
+        .hasIndex = GPBNoHasBit,
+        .flags = GPBFieldRepeated,
+        .type = GPBTypeMessage,
+        .offset = offsetof(GPBField_Storage, optionsArray),
+        .defaultValue.valueMessage = nil,
+        .typeSpecific.className = GPBStringifySymbol(GPBOption),
+        .fieldOptions = NULL,
+      },
+    };
+    static GPBMessageEnumDescription enums[] = {
+      { .enumDescriptorFunc = GPBField_Kind_EnumDescriptor },
+      { .enumDescriptorFunc = GPBField_Cardinality_EnumDescriptor },
+    };
+#if GPBOBJC_SKIP_MESSAGE_TEXTFORMAT_EXTRAS
+    const char *extraTextFormatInfo = NULL;
+#else
+    static const char *extraTextFormatInfo = "\001\006\004\241!!\000";
+#endif  // GPBOBJC_SKIP_MESSAGE_TEXTFORMAT_EXTRAS
+    descriptor = [GPBDescriptor allocDescriptorForClass:[GPBField class]
+                                              rootClass:[GPBTypeRoot class]
+                                                   file:GPBTypeRoot_FileDescriptor()
+                                                 fields:fields
+                                             fieldCount:sizeof(fields) / sizeof(GPBMessageFieldDescription)
+                                                 oneofs:NULL
+                                             oneofCount:0
+                                                  enums:enums
+                                              enumCount:sizeof(enums) / sizeof(GPBMessageEnumDescription)
+                                                 ranges:NULL
+                                             rangeCount:0
+                                            storageSize:sizeof(GPBField_Storage)
+                                             wireFormat:NO
+                                    extraTextFormatInfo:extraTextFormatInfo];
+  }
+  return descriptor;
+}
+
+@end
+
+int32_t GPBField_Kind_RawValue(GPBField *message) {
+  GPBDescriptor *descriptor = [GPBField descriptor];
+  GPBFieldDescriptor *field = [descriptor fieldWithNumber:GPBField_FieldNumber_Kind];
+  return GPBGetInt32IvarWithField(message, field);
+}
+
+void SetGPBField_Kind_RawValue(GPBField *message, int32_t value) {
+  GPBDescriptor *descriptor = [GPBField descriptor];
+  GPBFieldDescriptor *field = [descriptor fieldWithNumber:GPBField_FieldNumber_Kind];
+  GPBSetInt32IvarWithFieldInternal(message, field, value, descriptor.file.syntax);
+}
+
+int32_t GPBField_Cardinality_RawValue(GPBField *message) {
+  GPBDescriptor *descriptor = [GPBField descriptor];
+  GPBFieldDescriptor *field = [descriptor fieldWithNumber:GPBField_FieldNumber_Cardinality];
+  return GPBGetInt32IvarWithField(message, field);
+}
+
+void SetGPBField_Cardinality_RawValue(GPBField *message, int32_t value) {
+  GPBDescriptor *descriptor = [GPBField descriptor];
+  GPBFieldDescriptor *field = [descriptor fieldWithNumber:GPBField_FieldNumber_Cardinality];
+  GPBSetInt32IvarWithFieldInternal(message, field, value, descriptor.file.syntax);
+}
+
+#pragma mark - Enum GPBField_Kind
+
+GPBEnumDescriptor *GPBField_Kind_EnumDescriptor(void) {
+  static GPBEnumDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    static GPBMessageEnumValueDescription values[] = {
+      { .name = "TypeUnknown", .number = GPBField_Kind_TypeUnknown },
+      { .name = "TypeDouble", .number = GPBField_Kind_TypeDouble },
+      { .name = "TypeFloat", .number = GPBField_Kind_TypeFloat },
+      { .name = "TypeInt64", .number = GPBField_Kind_TypeInt64 },
+      { .name = "TypeUint64", .number = GPBField_Kind_TypeUint64 },
+      { .name = "TypeInt32", .number = GPBField_Kind_TypeInt32 },
+      { .name = "TypeFixed64", .number = GPBField_Kind_TypeFixed64 },
+      { .name = "TypeFixed32", .number = GPBField_Kind_TypeFixed32 },
+      { .name = "TypeBool", .number = GPBField_Kind_TypeBool },
+      { .name = "TypeString", .number = GPBField_Kind_TypeString },
+      { .name = "TypeMessage", .number = GPBField_Kind_TypeMessage },
+      { .name = "TypeBytes", .number = GPBField_Kind_TypeBytes },
+      { .name = "TypeUint32", .number = GPBField_Kind_TypeUint32 },
+      { .name = "TypeEnum", .number = GPBField_Kind_TypeEnum },
+      { .name = "TypeSfixed32", .number = GPBField_Kind_TypeSfixed32 },
+      { .name = "TypeSfixed64", .number = GPBField_Kind_TypeSfixed64 },
+      { .name = "TypeSint32", .number = GPBField_Kind_TypeSint32 },
+      { .name = "TypeSint64", .number = GPBField_Kind_TypeSint64 },
+    };
+    descriptor = [GPBEnumDescriptor allocDescriptorForName:GPBNSStringifySymbol(GPBField_Kind)
+                                                   values:values
+                                               valueCount:sizeof(values) / sizeof(GPBMessageEnumValueDescription)
+                                             enumVerifier:GPBField_Kind_IsValidValue];
+  }
+  return descriptor;
+}
+
+BOOL GPBField_Kind_IsValidValue(int32_t value__) {
+  switch (value__) {
+    case GPBField_Kind_TypeUnknown:
+    case GPBField_Kind_TypeDouble:
+    case GPBField_Kind_TypeFloat:
+    case GPBField_Kind_TypeInt64:
+    case GPBField_Kind_TypeUint64:
+    case GPBField_Kind_TypeInt32:
+    case GPBField_Kind_TypeFixed64:
+    case GPBField_Kind_TypeFixed32:
+    case GPBField_Kind_TypeBool:
+    case GPBField_Kind_TypeString:
+    case GPBField_Kind_TypeMessage:
+    case GPBField_Kind_TypeBytes:
+    case GPBField_Kind_TypeUint32:
+    case GPBField_Kind_TypeEnum:
+    case GPBField_Kind_TypeSfixed32:
+    case GPBField_Kind_TypeSfixed64:
+    case GPBField_Kind_TypeSint32:
+    case GPBField_Kind_TypeSint64:
+      return YES;
+    default:
+      return NO;
+  }
+}
+
+#pragma mark - Enum GPBField_Cardinality
+
+GPBEnumDescriptor *GPBField_Cardinality_EnumDescriptor(void) {
+  static GPBEnumDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    static GPBMessageEnumValueDescription values[] = {
+      { .name = "CardinalityUnknown", .number = GPBField_Cardinality_CardinalityUnknown },
+      { .name = "CardinalityOptional", .number = GPBField_Cardinality_CardinalityOptional },
+      { .name = "CardinalityRequired", .number = GPBField_Cardinality_CardinalityRequired },
+      { .name = "CardinalityRepeated", .number = GPBField_Cardinality_CardinalityRepeated },
+    };
+    descriptor = [GPBEnumDescriptor allocDescriptorForName:GPBNSStringifySymbol(GPBField_Cardinality)
+                                                   values:values
+                                               valueCount:sizeof(values) / sizeof(GPBMessageEnumValueDescription)
+                                             enumVerifier:GPBField_Cardinality_IsValidValue];
+  }
+  return descriptor;
+}
+
+BOOL GPBField_Cardinality_IsValidValue(int32_t value__) {
+  switch (value__) {
+    case GPBField_Cardinality_CardinalityUnknown:
+    case GPBField_Cardinality_CardinalityOptional:
+    case GPBField_Cardinality_CardinalityRequired:
+    case GPBField_Cardinality_CardinalityRepeated:
+      return YES;
+    default:
+      return NO;
+  }
+}
+
+#pragma mark - GPBEnum
+
+@implementation GPBEnum
+
+@dynamic name;
+@dynamic enumvalueArray;
+@dynamic optionsArray;
+@dynamic hasSourceContext, sourceContext;
+
+typedef struct GPBEnum_Storage {
+  uint32_t _has_storage_[1];
+  NSString *name;
+  NSMutableArray *enumvalueArray;
+  NSMutableArray *optionsArray;
+  GPBSourceContext *sourceContext;
+} GPBEnum_Storage;
+
+// This method is threadsafe because it is initially called
+// in +initialize for each subclass.
++ (GPBDescriptor *)descriptor {
+  static GPBDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    static GPBMessageFieldDescription fields[] = {
+      {
+        .name = "name",
+        .number = GPBEnum_FieldNumber_Name,
+        .hasIndex = 0,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeString,
+        .offset = offsetof(GPBEnum_Storage, name),
+        .defaultValue.valueString = nil,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+      {
+        .name = "enumvalueArray",
+        .number = GPBEnum_FieldNumber_EnumvalueArray,
+        .hasIndex = GPBNoHasBit,
+        .flags = GPBFieldRepeated,
+        .type = GPBTypeMessage,
+        .offset = offsetof(GPBEnum_Storage, enumvalueArray),
+        .defaultValue.valueMessage = nil,
+        .typeSpecific.className = GPBStringifySymbol(GPBEnumValue),
+        .fieldOptions = NULL,
+      },
+      {
+        .name = "optionsArray",
+        .number = GPBEnum_FieldNumber_OptionsArray,
+        .hasIndex = GPBNoHasBit,
+        .flags = GPBFieldRepeated,
+        .type = GPBTypeMessage,
+        .offset = offsetof(GPBEnum_Storage, optionsArray),
+        .defaultValue.valueMessage = nil,
+        .typeSpecific.className = GPBStringifySymbol(GPBOption),
+        .fieldOptions = NULL,
+      },
+      {
+        .name = "sourceContext",
+        .number = GPBEnum_FieldNumber_SourceContext,
+        .hasIndex = 3,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeMessage,
+        .offset = offsetof(GPBEnum_Storage, sourceContext),
+        .defaultValue.valueMessage = nil,
+        .typeSpecific.className = GPBStringifySymbol(GPBSourceContext),
+        .fieldOptions = NULL,
+      },
+    };
+    descriptor = [GPBDescriptor allocDescriptorForClass:[GPBEnum class]
+                                              rootClass:[GPBTypeRoot class]
+                                                   file:GPBTypeRoot_FileDescriptor()
+                                                 fields:fields
+                                             fieldCount:sizeof(fields) / sizeof(GPBMessageFieldDescription)
+                                                 oneofs:NULL
+                                             oneofCount:0
+                                                  enums:NULL
+                                              enumCount:0
+                                                 ranges:NULL
+                                             rangeCount:0
+                                            storageSize:sizeof(GPBEnum_Storage)
+                                             wireFormat:NO];
+  }
+  return descriptor;
+}
+
+@end
+
+#pragma mark - GPBEnumValue
+
+@implementation GPBEnumValue
+
+@dynamic name;
+@dynamic number;
+@dynamic optionsArray;
+
+typedef struct GPBEnumValue_Storage {
+  uint32_t _has_storage_[1];
+  int32_t number;
+  NSString *name;
+  NSMutableArray *optionsArray;
+} GPBEnumValue_Storage;
+
+// This method is threadsafe because it is initially called
+// in +initialize for each subclass.
++ (GPBDescriptor *)descriptor {
+  static GPBDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    static GPBMessageFieldDescription fields[] = {
+      {
+        .name = "name",
+        .number = GPBEnumValue_FieldNumber_Name,
+        .hasIndex = 0,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeString,
+        .offset = offsetof(GPBEnumValue_Storage, name),
+        .defaultValue.valueString = nil,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+      {
+        .name = "number",
+        .number = GPBEnumValue_FieldNumber_Number,
+        .hasIndex = 1,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeInt32,
+        .offset = offsetof(GPBEnumValue_Storage, number),
+        .defaultValue.valueInt32 = 0,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+      {
+        .name = "optionsArray",
+        .number = GPBEnumValue_FieldNumber_OptionsArray,
+        .hasIndex = GPBNoHasBit,
+        .flags = GPBFieldRepeated,
+        .type = GPBTypeMessage,
+        .offset = offsetof(GPBEnumValue_Storage, optionsArray),
+        .defaultValue.valueMessage = nil,
+        .typeSpecific.className = GPBStringifySymbol(GPBOption),
+        .fieldOptions = NULL,
+      },
+    };
+    descriptor = [GPBDescriptor allocDescriptorForClass:[GPBEnumValue class]
+                                              rootClass:[GPBTypeRoot class]
+                                                   file:GPBTypeRoot_FileDescriptor()
+                                                 fields:fields
+                                             fieldCount:sizeof(fields) / sizeof(GPBMessageFieldDescription)
+                                                 oneofs:NULL
+                                             oneofCount:0
+                                                  enums:NULL
+                                              enumCount:0
+                                                 ranges:NULL
+                                             rangeCount:0
+                                            storageSize:sizeof(GPBEnumValue_Storage)
+                                             wireFormat:NO];
+  }
+  return descriptor;
+}
+
+@end
+
+#pragma mark - GPBOption
+
+@implementation GPBOption
+
+@dynamic name;
+@dynamic hasValue, value;
+
+typedef struct GPBOption_Storage {
+  uint32_t _has_storage_[1];
+  NSString *name;
+  GPBAny *value;
+} GPBOption_Storage;
+
+// This method is threadsafe because it is initially called
+// in +initialize for each subclass.
++ (GPBDescriptor *)descriptor {
+  static GPBDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    static GPBMessageFieldDescription fields[] = {
+      {
+        .name = "name",
+        .number = GPBOption_FieldNumber_Name,
+        .hasIndex = 0,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeString,
+        .offset = offsetof(GPBOption_Storage, name),
+        .defaultValue.valueString = nil,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+      {
+        .name = "value",
+        .number = GPBOption_FieldNumber_Value,
+        .hasIndex = 1,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeMessage,
+        .offset = offsetof(GPBOption_Storage, value),
+        .defaultValue.valueMessage = nil,
+        .typeSpecific.className = GPBStringifySymbol(GPBAny),
+        .fieldOptions = NULL,
+      },
+    };
+    descriptor = [GPBDescriptor allocDescriptorForClass:[GPBOption class]
+                                              rootClass:[GPBTypeRoot class]
+                                                   file:GPBTypeRoot_FileDescriptor()
+                                                 fields:fields
+                                             fieldCount:sizeof(fields) / sizeof(GPBMessageFieldDescription)
+                                                 oneofs:NULL
+                                             oneofCount:0
+                                                  enums:NULL
+                                              enumCount:0
+                                                 ranges:NULL
+                                             rangeCount:0
+                                            storageSize:sizeof(GPBOption_Storage)
+                                             wireFormat:NO];
+  }
+  return descriptor;
+}
+
+@end
+
+
+// @@protoc_insertion_point(global_scope)
diff --git a/objectivec/google/protobuf/Wrappers.pbobjc.h b/objectivec/google/protobuf/Wrappers.pbobjc.h
new file mode 100644
index 00000000..227d958e
--- /dev/null
+++ b/objectivec/google/protobuf/Wrappers.pbobjc.h
@@ -0,0 +1,154 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: google/protobuf/wrappers.proto
+
+#import "GPBProtocolBuffers.h"
+
+#if GOOGLE_PROTOBUF_OBJC_GEN_VERSION != 30000
+#error This file was generated by a different version of protoc-gen-objc which is incompatible with your Protocol Buffer sources.
+#endif
+
+// @@protoc_insertion_point(imports)
+
+CF_EXTERN_C_BEGIN
+
+
+#pragma mark - GPBWrappersRoot
+
+@interface GPBWrappersRoot : GPBRootObject
+
+// The base class provides:
+//   + (GPBExtensionRegistry *)extensionRegistry;
+// which is an GPBExtensionRegistry that includes all the extensions defined by
+// this file and all files that it depends on.
+
+@end
+
+#pragma mark - GPBDoubleValue
+
+typedef GPB_ENUM(GPBDoubleValue_FieldNumber) {
+  GPBDoubleValue_FieldNumber_Value = 1,
+};
+
+// Wrapper message for double.
+@interface GPBDoubleValue : GPBMessage
+
+// The double value.
+@property(nonatomic, readwrite) double value;
+
+@end
+
+#pragma mark - GPBFloatValue
+
+typedef GPB_ENUM(GPBFloatValue_FieldNumber) {
+  GPBFloatValue_FieldNumber_Value = 1,
+};
+
+// Wrapper message for float.
+@interface GPBFloatValue : GPBMessage
+
+// The float value.
+@property(nonatomic, readwrite) float value;
+
+@end
+
+#pragma mark - GPBInt64Value
+
+typedef GPB_ENUM(GPBInt64Value_FieldNumber) {
+  GPBInt64Value_FieldNumber_Value = 1,
+};
+
+// Wrapper message for int64.
+@interface GPBInt64Value : GPBMessage
+
+// The int64 value.
+@property(nonatomic, readwrite) int64_t value;
+
+@end
+
+#pragma mark - GPBUInt64Value
+
+typedef GPB_ENUM(GPBUInt64Value_FieldNumber) {
+  GPBUInt64Value_FieldNumber_Value = 1,
+};
+
+// Wrapper message for uint64.
+@interface GPBUInt64Value : GPBMessage
+
+// The uint64 value.
+@property(nonatomic, readwrite) uint64_t value;
+
+@end
+
+#pragma mark - GPBInt32Value
+
+typedef GPB_ENUM(GPBInt32Value_FieldNumber) {
+  GPBInt32Value_FieldNumber_Value = 1,
+};
+
+// Wrapper message for int32.
+@interface GPBInt32Value : GPBMessage
+
+// The int32 value.
+@property(nonatomic, readwrite) int32_t value;
+
+@end
+
+#pragma mark - GPBUInt32Value
+
+typedef GPB_ENUM(GPBUInt32Value_FieldNumber) {
+  GPBUInt32Value_FieldNumber_Value = 1,
+};
+
+// Wrapper message for uint32.
+@interface GPBUInt32Value : GPBMessage
+
+// The uint32 value.
+@property(nonatomic, readwrite) uint32_t value;
+
+@end
+
+#pragma mark - GPBBoolValue
+
+typedef GPB_ENUM(GPBBoolValue_FieldNumber) {
+  GPBBoolValue_FieldNumber_Value = 1,
+};
+
+// Wrapper message for bool.
+@interface GPBBoolValue : GPBMessage
+
+// The bool value.
+@property(nonatomic, readwrite) BOOL value;
+
+@end
+
+#pragma mark - GPBStringValue
+
+typedef GPB_ENUM(GPBStringValue_FieldNumber) {
+  GPBStringValue_FieldNumber_Value = 1,
+};
+
+// Wrapper message for string.
+@interface GPBStringValue : GPBMessage
+
+// The string value.
+@property(nonatomic, readwrite, copy) NSString *value;
+
+@end
+
+#pragma mark - GPBBytesValue
+
+typedef GPB_ENUM(GPBBytesValue_FieldNumber) {
+  GPBBytesValue_FieldNumber_Value = 1,
+};
+
+// Wrapper message for bytes.
+@interface GPBBytesValue : GPBMessage
+
+// The bytes value.
+@property(nonatomic, readwrite, copy) NSData *value;
+
+@end
+
+CF_EXTERN_C_END
+
+// @@protoc_insertion_point(global_scope)
diff --git a/objectivec/google/protobuf/Wrappers.pbobjc.m b/objectivec/google/protobuf/Wrappers.pbobjc.m
new file mode 100644
index 00000000..6c342850
--- /dev/null
+++ b/objectivec/google/protobuf/Wrappers.pbobjc.m
@@ -0,0 +1,458 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: google/protobuf/wrappers.proto
+
+#import "GPBProtocolBuffers_RuntimeSupport.h"
+#import "google/protobuf/Wrappers.pbobjc.h"
+// @@protoc_insertion_point(imports)
+
+#pragma mark - GPBWrappersRoot
+
+@implementation GPBWrappersRoot
+
+@end
+
+static GPBFileDescriptor *GPBWrappersRoot_FileDescriptor(void) {
+  // This is called by +initialize so there is no need to worry
+  // about thread safety of the singleton.
+  static GPBFileDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    descriptor = [[GPBFileDescriptor alloc] initWithPackage:@"google.protobuf"
+                                                     syntax:GPBFileSyntaxProto3];
+  }
+  return descriptor;
+}
+
+#pragma mark - GPBDoubleValue
+
+@implementation GPBDoubleValue
+
+@dynamic value;
+
+typedef struct GPBDoubleValue_Storage {
+  uint32_t _has_storage_[1];
+  double value;
+} GPBDoubleValue_Storage;
+
+// This method is threadsafe because it is initially called
+// in +initialize for each subclass.
++ (GPBDescriptor *)descriptor {
+  static GPBDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    static GPBMessageFieldDescription fields[] = {
+      {
+        .name = "value",
+        .number = GPBDoubleValue_FieldNumber_Value,
+        .hasIndex = 0,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeDouble,
+        .offset = offsetof(GPBDoubleValue_Storage, value),
+        .defaultValue.valueDouble = 0,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+    };
+    descriptor = [GPBDescriptor allocDescriptorForClass:[GPBDoubleValue class]
+                                              rootClass:[GPBWrappersRoot class]
+                                                   file:GPBWrappersRoot_FileDescriptor()
+                                                 fields:fields
+                                             fieldCount:sizeof(fields) / sizeof(GPBMessageFieldDescription)
+                                                 oneofs:NULL
+                                             oneofCount:0
+                                                  enums:NULL
+                                              enumCount:0
+                                                 ranges:NULL
+                                             rangeCount:0
+                                            storageSize:sizeof(GPBDoubleValue_Storage)
+                                             wireFormat:NO];
+  }
+  return descriptor;
+}
+
+@end
+
+#pragma mark - GPBFloatValue
+
+@implementation GPBFloatValue
+
+@dynamic value;
+
+typedef struct GPBFloatValue_Storage {
+  uint32_t _has_storage_[1];
+  float value;
+} GPBFloatValue_Storage;
+
+// This method is threadsafe because it is initially called
+// in +initialize for each subclass.
++ (GPBDescriptor *)descriptor {
+  static GPBDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    static GPBMessageFieldDescription fields[] = {
+      {
+        .name = "value",
+        .number = GPBFloatValue_FieldNumber_Value,
+        .hasIndex = 0,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeFloat,
+        .offset = offsetof(GPBFloatValue_Storage, value),
+        .defaultValue.valueFloat = 0,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+    };
+    descriptor = [GPBDescriptor allocDescriptorForClass:[GPBFloatValue class]
+                                              rootClass:[GPBWrappersRoot class]
+                                                   file:GPBWrappersRoot_FileDescriptor()
+                                                 fields:fields
+                                             fieldCount:sizeof(fields) / sizeof(GPBMessageFieldDescription)
+                                                 oneofs:NULL
+                                             oneofCount:0
+                                                  enums:NULL
+                                              enumCount:0
+                                                 ranges:NULL
+                                             rangeCount:0
+                                            storageSize:sizeof(GPBFloatValue_Storage)
+                                             wireFormat:NO];
+  }
+  return descriptor;
+}
+
+@end
+
+#pragma mark - GPBInt64Value
+
+@implementation GPBInt64Value
+
+@dynamic value;
+
+typedef struct GPBInt64Value_Storage {
+  uint32_t _has_storage_[1];
+  int64_t value;
+} GPBInt64Value_Storage;
+
+// This method is threadsafe because it is initially called
+// in +initialize for each subclass.
++ (GPBDescriptor *)descriptor {
+  static GPBDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    static GPBMessageFieldDescription fields[] = {
+      {
+        .name = "value",
+        .number = GPBInt64Value_FieldNumber_Value,
+        .hasIndex = 0,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeInt64,
+        .offset = offsetof(GPBInt64Value_Storage, value),
+        .defaultValue.valueInt64 = 0LL,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+    };
+    descriptor = [GPBDescriptor allocDescriptorForClass:[GPBInt64Value class]
+                                              rootClass:[GPBWrappersRoot class]
+                                                   file:GPBWrappersRoot_FileDescriptor()
+                                                 fields:fields
+                                             fieldCount:sizeof(fields) / sizeof(GPBMessageFieldDescription)
+                                                 oneofs:NULL
+                                             oneofCount:0
+                                                  enums:NULL
+                                              enumCount:0
+                                                 ranges:NULL
+                                             rangeCount:0
+                                            storageSize:sizeof(GPBInt64Value_Storage)
+                                             wireFormat:NO];
+  }
+  return descriptor;
+}
+
+@end
+
+#pragma mark - GPBUInt64Value
+
+@implementation GPBUInt64Value
+
+@dynamic value;
+
+typedef struct GPBUInt64Value_Storage {
+  uint32_t _has_storage_[1];
+  uint64_t value;
+} GPBUInt64Value_Storage;
+
+// This method is threadsafe because it is initially called
+// in +initialize for each subclass.
++ (GPBDescriptor *)descriptor {
+  static GPBDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    static GPBMessageFieldDescription fields[] = {
+      {
+        .name = "value",
+        .number = GPBUInt64Value_FieldNumber_Value,
+        .hasIndex = 0,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeUInt64,
+        .offset = offsetof(GPBUInt64Value_Storage, value),
+        .defaultValue.valueUInt64 = 0ULL,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+    };
+    descriptor = [GPBDescriptor allocDescriptorForClass:[GPBUInt64Value class]
+                                              rootClass:[GPBWrappersRoot class]
+                                                   file:GPBWrappersRoot_FileDescriptor()
+                                                 fields:fields
+                                             fieldCount:sizeof(fields) / sizeof(GPBMessageFieldDescription)
+                                                 oneofs:NULL
+                                             oneofCount:0
+                                                  enums:NULL
+                                              enumCount:0
+                                                 ranges:NULL
+                                             rangeCount:0
+                                            storageSize:sizeof(GPBUInt64Value_Storage)
+                                             wireFormat:NO];
+  }
+  return descriptor;
+}
+
+@end
+
+#pragma mark - GPBInt32Value
+
+@implementation GPBInt32Value
+
+@dynamic value;
+
+typedef struct GPBInt32Value_Storage {
+  uint32_t _has_storage_[1];
+  int32_t value;
+} GPBInt32Value_Storage;
+
+// This method is threadsafe because it is initially called
+// in +initialize for each subclass.
++ (GPBDescriptor *)descriptor {
+  static GPBDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    static GPBMessageFieldDescription fields[] = {
+      {
+        .name = "value",
+        .number = GPBInt32Value_FieldNumber_Value,
+        .hasIndex = 0,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeInt32,
+        .offset = offsetof(GPBInt32Value_Storage, value),
+        .defaultValue.valueInt32 = 0,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+    };
+    descriptor = [GPBDescriptor allocDescriptorForClass:[GPBInt32Value class]
+                                              rootClass:[GPBWrappersRoot class]
+                                                   file:GPBWrappersRoot_FileDescriptor()
+                                                 fields:fields
+                                             fieldCount:sizeof(fields) / sizeof(GPBMessageFieldDescription)
+                                                 oneofs:NULL
+                                             oneofCount:0
+                                                  enums:NULL
+                                              enumCount:0
+                                                 ranges:NULL
+                                             rangeCount:0
+                                            storageSize:sizeof(GPBInt32Value_Storage)
+                                             wireFormat:NO];
+  }
+  return descriptor;
+}
+
+@end
+
+#pragma mark - GPBUInt32Value
+
+@implementation GPBUInt32Value
+
+@dynamic value;
+
+typedef struct GPBUInt32Value_Storage {
+  uint32_t _has_storage_[1];
+  uint32_t value;
+} GPBUInt32Value_Storage;
+
+// This method is threadsafe because it is initially called
+// in +initialize for each subclass.
++ (GPBDescriptor *)descriptor {
+  static GPBDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    static GPBMessageFieldDescription fields[] = {
+      {
+        .name = "value",
+        .number = GPBUInt32Value_FieldNumber_Value,
+        .hasIndex = 0,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeUInt32,
+        .offset = offsetof(GPBUInt32Value_Storage, value),
+        .defaultValue.valueUInt32 = 0U,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+    };
+    descriptor = [GPBDescriptor allocDescriptorForClass:[GPBUInt32Value class]
+                                              rootClass:[GPBWrappersRoot class]
+                                                   file:GPBWrappersRoot_FileDescriptor()
+                                                 fields:fields
+                                             fieldCount:sizeof(fields) / sizeof(GPBMessageFieldDescription)
+                                                 oneofs:NULL
+                                             oneofCount:0
+                                                  enums:NULL
+                                              enumCount:0
+                                                 ranges:NULL
+                                             rangeCount:0
+                                            storageSize:sizeof(GPBUInt32Value_Storage)
+                                             wireFormat:NO];
+  }
+  return descriptor;
+}
+
+@end
+
+#pragma mark - GPBBoolValue
+
+@implementation GPBBoolValue
+
+@dynamic value;
+
+typedef struct GPBBoolValue_Storage {
+  uint32_t _has_storage_[1];
+  BOOL value;
+} GPBBoolValue_Storage;
+
+// This method is threadsafe because it is initially called
+// in +initialize for each subclass.
++ (GPBDescriptor *)descriptor {
+  static GPBDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    static GPBMessageFieldDescription fields[] = {
+      {
+        .name = "value",
+        .number = GPBBoolValue_FieldNumber_Value,
+        .hasIndex = 0,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeBool,
+        .offset = offsetof(GPBBoolValue_Storage, value),
+        .defaultValue.valueBool = NO,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+    };
+    descriptor = [GPBDescriptor allocDescriptorForClass:[GPBBoolValue class]
+                                              rootClass:[GPBWrappersRoot class]
+                                                   file:GPBWrappersRoot_FileDescriptor()
+                                                 fields:fields
+                                             fieldCount:sizeof(fields) / sizeof(GPBMessageFieldDescription)
+                                                 oneofs:NULL
+                                             oneofCount:0
+                                                  enums:NULL
+                                              enumCount:0
+                                                 ranges:NULL
+                                             rangeCount:0
+                                            storageSize:sizeof(GPBBoolValue_Storage)
+                                             wireFormat:NO];
+  }
+  return descriptor;
+}
+
+@end
+
+#pragma mark - GPBStringValue
+
+@implementation GPBStringValue
+
+@dynamic value;
+
+typedef struct GPBStringValue_Storage {
+  uint32_t _has_storage_[1];
+  NSString *value;
+} GPBStringValue_Storage;
+
+// This method is threadsafe because it is initially called
+// in +initialize for each subclass.
++ (GPBDescriptor *)descriptor {
+  static GPBDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    static GPBMessageFieldDescription fields[] = {
+      {
+        .name = "value",
+        .number = GPBStringValue_FieldNumber_Value,
+        .hasIndex = 0,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeString,
+        .offset = offsetof(GPBStringValue_Storage, value),
+        .defaultValue.valueString = nil,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+    };
+    descriptor = [GPBDescriptor allocDescriptorForClass:[GPBStringValue class]
+                                              rootClass:[GPBWrappersRoot class]
+                                                   file:GPBWrappersRoot_FileDescriptor()
+                                                 fields:fields
+                                             fieldCount:sizeof(fields) / sizeof(GPBMessageFieldDescription)
+                                                 oneofs:NULL
+                                             oneofCount:0
+                                                  enums:NULL
+                                              enumCount:0
+                                                 ranges:NULL
+                                             rangeCount:0
+                                            storageSize:sizeof(GPBStringValue_Storage)
+                                             wireFormat:NO];
+  }
+  return descriptor;
+}
+
+@end
+
+#pragma mark - GPBBytesValue
+
+@implementation GPBBytesValue
+
+@dynamic value;
+
+typedef struct GPBBytesValue_Storage {
+  uint32_t _has_storage_[1];
+  NSData *value;
+} GPBBytesValue_Storage;
+
+// This method is threadsafe because it is initially called
+// in +initialize for each subclass.
++ (GPBDescriptor *)descriptor {
+  static GPBDescriptor *descriptor = NULL;
+  if (!descriptor) {
+    static GPBMessageFieldDescription fields[] = {
+      {
+        .name = "value",
+        .number = GPBBytesValue_FieldNumber_Value,
+        .hasIndex = 0,
+        .flags = GPBFieldOptional,
+        .type = GPBTypeData,
+        .offset = offsetof(GPBBytesValue_Storage, value),
+        .defaultValue.valueData = nil,
+        .typeSpecific.className = NULL,
+        .fieldOptions = NULL,
+      },
+    };
+    descriptor = [GPBDescriptor allocDescriptorForClass:[GPBBytesValue class]
+                                              rootClass:[GPBWrappersRoot class]
+                                                   file:GPBWrappersRoot_FileDescriptor()
+                                                 fields:fields
+                                             fieldCount:sizeof(fields) / sizeof(GPBMessageFieldDescription)
+                                                 oneofs:NULL
+                                             oneofCount:0
+                                                  enums:NULL
+                                              enumCount:0
+                                                 ranges:NULL
+                                             rangeCount:0
+                                            storageSize:sizeof(GPBBytesValue_Storage)
+                                             wireFormat:NO];
+  }
+  return descriptor;
+}
+
+@end
+
+
+// @@protoc_insertion_point(global_scope)