Down integrate from Google internal.

Change-Id: I34d301133eea9c6f3a822c47d1f91e136fd33145

3 files changed, 69 insertions, 10 deletions

diff --git a/src/google/protobuf/compiler/python/python_generator.cc b/src/google/protobuf/compiler/python/python_generator.cc
index 0c65b993..7b3b5fa3 100644
--- a/src/google/protobuf/compiler/python/python_generator.cc
+++ b/src/google/protobuf/compiler/python/python_generator.cc
@@ -273,6 +273,19 @@ string StringifyDefaultValue(const FieldDescriptor& field) {
   return "";
 }
 
+string StringifySyntax(FileDescriptor::Syntax syntax) {
+  switch (syntax) {
+    case FileDescriptor::SYNTAX_PROTO2:
+      return "proto2";
+    case FileDescriptor::SYNTAX_PROTO3:
+      return "proto3";
+    case FileDescriptor::SYNTAX_UNKNOWN:
+    default:
+      GOOGLE_LOG(FATAL) << "Unsupported syntax; this generator only supports proto2 "
+                    "and proto3 syntax.";
+      return "";
+  }
+}
 
 
 }  // namespace
@@ -367,10 +380,12 @@ void Generator::PrintFileDescriptor() const {
   m["descriptor_name"] = kDescriptorKey;
   m["name"] = file_->name();
   m["package"] = file_->package();
+  m["syntax"] = StringifySyntax(file_->syntax());
   const char file_descriptor_template[] =
       "$descriptor_name$ = _descriptor.FileDescriptor(\n"
       "  name='$name$',\n"
-      "  package='$package$',\n";
+      "  package='$package$',\n"
+      "  syntax='$syntax$',\n";
   printer_->Print(m, file_descriptor_template);
   printer_->Indent();
   printer_->Print(
@@ -414,7 +429,7 @@ void Generator::PrintTopLevelEnums() const {
     for (int j = 0; j < enum_descriptor.value_count(); ++j) {
       const EnumValueDescriptor& value_descriptor = *enum_descriptor.value(j);
       top_level_enum_values.push_back(
-          make_pair(value_descriptor.name(), value_descriptor.number()));
+          std::make_pair(value_descriptor.name(), value_descriptor.number()));
     }
   }
 
@@ -665,10 +680,12 @@ void Generator::PrintDescriptor(const Descriptor& message_descriptor) const {
   message_descriptor.options().SerializeToString(&options_string);
   printer_->Print(
       "options=$options_value$,\n"
-      "is_extendable=$extendable$",
+      "is_extendable=$extendable$,\n"
+      "syntax='$syntax$'",
       "options_value", OptionsValue("MessageOptions", options_string),
       "extendable", message_descriptor.extension_range_count() > 0 ?
-                      "True" : "False");
+                      "True" : "False",
+      "syntax", StringifySyntax(message_descriptor.file()->syntax()));
   printer_->Print(",\n");
 
   // Extension ranges
diff --git a/src/google/protobuf/testdata/golden_message_proto3 b/src/google/protobuf/testdata/golden_message_proto3
new file mode 100644
index 00000000..934f36fa
--- /dev/null
+++ b/src/google/protobuf/testdata/golden_message_proto3
diff --git a/src/google/protobuf/unittest_proto3_arena.proto b/src/google/protobuf/unittest_proto3_arena.proto
index 53f23d87..6d7bada8 100644
--- a/src/google/protobuf/unittest_proto3_arena.proto
+++ b/src/google/protobuf/unittest_proto3_arena.proto
@@ -47,9 +47,10 @@ message TestAllTypes {
   }
 
   enum NestedEnum {
-    FOO = 0;
-    BAR = 1;
-    BAZ = 2;
+    ZERO = 0;
+    FOO = 1;
+    BAR = 2;
+    BAZ = 3;
     NEG = -1;  // Intentionally negative.
   }
 
@@ -81,6 +82,11 @@ message TestAllTypes {
   optional NestedEnum                           optional_nested_enum     = 21;
   optional ForeignEnum                          optional_foreign_enum    = 22;
 
+  // Omitted (compared to unittest.proto) because proto2 enums are not allowed
+  // inside proto2 messages.
+  //
+  // optional protobuf_unittest_import.ImportEnum    optional_import_enum  = 23;
+
   optional string optional_string_piece = 24 [ctype=STRING_PIECE];
   optional string optional_cord = 25 [ctype=CORD];
 
@@ -118,6 +124,11 @@ message TestAllTypes {
   repeated NestedEnum                           repeated_nested_enum     = 51;
   repeated ForeignEnum                          repeated_foreign_enum    = 52;
 
+  // Omitted (compared to unittest.proto) because proto2 enums are not allowed
+  // inside proto2 messages.
+  //
+  // repeated protobuf_unittest_import.ImportEnum    repeated_import_enum  = 53;
+
   repeated string repeated_string_piece = 54 [ctype=STRING_PIECE];
   repeated string repeated_cord = 55 [ctype=CORD];
 
@@ -131,6 +142,31 @@ message TestAllTypes {
   }
 }
 
+// Test messages for packed fields
+
+message TestPackedTypes {
+  repeated    int32 packed_int32    =  90 [packed = true];
+  repeated    int64 packed_int64    =  91 [packed = true];
+  repeated   uint32 packed_uint32   =  92 [packed = true];
+  repeated   uint64 packed_uint64   =  93 [packed = true];
+  repeated   sint32 packed_sint32   =  94 [packed = true];
+  repeated   sint64 packed_sint64   =  95 [packed = true];
+  repeated  fixed32 packed_fixed32  =  96 [packed = true];
+  repeated  fixed64 packed_fixed64  =  97 [packed = true];
+  repeated sfixed32 packed_sfixed32 =  98 [packed = true];
+  repeated sfixed64 packed_sfixed64 =  99 [packed = true];
+  repeated    float packed_float    = 100 [packed = true];
+  repeated   double packed_double   = 101 [packed = true];
+  repeated     bool packed_bool     = 102 [packed = true];
+  repeated ForeignEnum packed_enum  = 103 [packed = true];
+}
+
+// This proto includes a recusively nested message.
+message NestedTestAllTypes {
+  NestedTestAllTypes child = 1;
+  TestAllTypes payload = 2;
+}
+
 // Define these after TestAllTypes to make sure the compiler can handle
 // that.
 message ForeignMessage {
@@ -138,7 +174,13 @@ message ForeignMessage {
 }
 
 enum ForeignEnum {
-  FOREIGN_FOO = 0;
-  FOREIGN_BAR = 1;
-  FOREIGN_BAZ = 2;
+  FOREIGN_ZERO = 0;
+  FOREIGN_FOO = 4;
+  FOREIGN_BAR = 5;
+  FOREIGN_BAZ = 6;
+}
+
+// TestEmptyMessage is used to test behavior of unknown fields.
+message TestEmptyMessage {
 }
+