Improve ObjC deprecated annotation support.

- Check the parent file options for deprecation when deciding to tag Messages
  and Enums as deprecated.
- Within the generated source push/pop the warning for implementing deprecated
  things around a deprecated class implementation.
- Annotate the methods generated for extension fields as deprecated.
- Add a testing .proto file that covers deprecated fields, messages, enums,
  enum values and compile it into the unittests to confirm things compile
  cleanly.
- Add a testing .proto file that uses the file level option to make everything
  deprecated and compile it into the unittests to confirm things compile
  cleanly.

5 files changed, 37 insertions, 6 deletions

diff --git a/src/google/protobuf/compiler/objectivec/objectivec_enum.cc b/src/google/protobuf/compiler/objectivec/objectivec_enum.cc
index 34e17823..02d60b3e 100644
--- a/src/google/protobuf/compiler/objectivec/objectivec_enum.cc
+++ b/src/google/protobuf/compiler/objectivec/objectivec_enum.cc
@@ -74,7 +74,7 @@ void EnumGenerator::GenerateHeader(io::Printer* printer) {
 
   printer->Print("$comments$typedef$deprecated_attribute$ GPB_ENUM($name$) {\n",
                  "comments", enum_comments,
-                 "deprecated_attribute", GetOptionalDeprecatedAttribute(descriptor_),
+                 "deprecated_attribute", GetOptionalDeprecatedAttribute(descriptor_, descriptor_->file()),
                  "name", name_);
   printer->Indent();
 
diff --git a/src/google/protobuf/compiler/objectivec/objectivec_extension.cc b/src/google/protobuf/compiler/objectivec/objectivec_extension.cc
index d0de1eca..7073173c 100644
--- a/src/google/protobuf/compiler/objectivec/objectivec_extension.cc
+++ b/src/google/protobuf/compiler/objectivec/objectivec_extension.cc
@@ -67,9 +67,12 @@ void ExtensionGenerator::GenerateMembersHeader(io::Printer* printer) {
   } else {
     vars["comments"] = "";
   }
+  // Unlike normal message fields, check if the file for the extension was
+  // deprecated.
+  vars["deprecated_attribute"] = GetOptionalDeprecatedAttribute(descriptor_, descriptor_->file());
   printer->Print(vars,
                  "$comments$"
-                 "+ (GPBExtensionDescriptor *)$method_name$;\n");
+                 "+ (GPBExtensionDescriptor *)$method_name$$deprecated_attribute$;\n");
 }
 
 void ExtensionGenerator::GenerateStaticVariablesInitialization(
diff --git a/src/google/protobuf/compiler/objectivec/objectivec_helpers.h b/src/google/protobuf/compiler/objectivec/objectivec_helpers.h
index 316069e1..a2179446 100644
--- a/src/google/protobuf/compiler/objectivec/objectivec_helpers.h
+++ b/src/google/protobuf/compiler/objectivec/objectivec_helpers.h
@@ -150,8 +150,18 @@ enum FlagType {
 };
 
 template<class TDescriptor>
-string GetOptionalDeprecatedAttribute(const TDescriptor* descriptor, bool preSpace = true, bool postNewline = false) {
-  if (descriptor->options().deprecated()) {
+string GetOptionalDeprecatedAttribute(
+    const TDescriptor* descriptor,
+    const FileDescriptor* file = NULL,
+    bool preSpace = true, bool postNewline = false) {
+  bool isDeprecated = descriptor->options().deprecated();
+  // The file is only passed when checking Messages & Enums, so those types
+  // get tagged. At the moment, it doesn't seem to make sense to tag every
+  // field or enum value with when the file is deprecated.
+  if (!isDeprecated && file) {
+    isDeprecated = file->options().deprecated();
+  }
+  if (isDeprecated) {
     string result = "DEPRECATED_ATTRIBUTE";
     if (preSpace) {
       result.insert(0, " ");
diff --git a/src/google/protobuf/compiler/objectivec/objectivec_message.cc b/src/google/protobuf/compiler/objectivec/objectivec_message.cc
index 4c6e1b55..e0bd3dac 100644
--- a/src/google/protobuf/compiler/objectivec/objectivec_message.cc
+++ b/src/google/protobuf/compiler/objectivec/objectivec_message.cc
@@ -180,7 +180,10 @@ MessageGenerator::MessageGenerator(const string& root_classname,
     : root_classname_(root_classname),
       descriptor_(descriptor),
       field_generators_(descriptor, options),
-      class_name_(ClassName(descriptor_)) {
+      class_name_(ClassName(descriptor_)),
+      deprecated_attribute_(
+          GetOptionalDeprecatedAttribute(descriptor, descriptor->file(), false, true)) {
+
   for (int i = 0; i < descriptor_->extension_count(); i++) {
     extension_generators_.push_back(
         new ExtensionGenerator(class_name_, descriptor_->extension(i)));
@@ -339,7 +342,7 @@ void MessageGenerator::GenerateMessageHeader(io::Printer* printer) {
   printer->Print(
       "$comments$$deprecated_attribute$@interface $classname$ : GPBMessage\n\n",
       "classname", class_name_,
-      "deprecated_attribute", GetOptionalDeprecatedAttribute(descriptor_, false, true),
+      "deprecated_attribute", deprecated_attribute_,
       "comments", message_comments);
 
   vector<char> seen_oneofs(descriptor_->oneof_decl_count(), 0);
@@ -396,6 +399,14 @@ void MessageGenerator::GenerateSource(io::Printer* printer) {
         "\n",
         "classname", class_name_);
 
+    if (!deprecated_attribute_.empty()) {
+      // No warnings when compiling the impl of this deprecated class.
+      printer->Print(
+          "#pragma clang diagnostic push\n"
+          "#pragma clang diagnostic ignored \"-Wdeprecated-implementations\"\n"
+          "\n");
+    }
+
     printer->Print("@implementation $classname$\n\n",
                    "classname", class_name_);
 
@@ -601,6 +612,12 @@ void MessageGenerator::GenerateSource(io::Printer* printer) {
         "}\n\n"
         "@end\n\n");
 
+    if (!deprecated_attribute_.empty()) {
+      printer->Print(
+          "#pragma clang diagnostic pop\n"
+          "\n");
+    }
+
     for (int i = 0; i < descriptor_->field_count(); i++) {
       field_generators_.get(descriptor_->field(i))
           .GenerateCFunctionImplementations(printer);
diff --git a/src/google/protobuf/compiler/objectivec/objectivec_message.h b/src/google/protobuf/compiler/objectivec/objectivec_message.h
index 910535ac..0fb78bc0 100644
--- a/src/google/protobuf/compiler/objectivec/objectivec_message.h
+++ b/src/google/protobuf/compiler/objectivec/objectivec_message.h
@@ -85,6 +85,7 @@ class MessageGenerator {
   const Descriptor* descriptor_;
   FieldGeneratorMap field_generators_;
   const string class_name_;
+  const string deprecated_attribute_;
   vector<ExtensionGenerator*> extension_generators_;
   vector<EnumGenerator*> enum_generators_;
   vector<MessageGenerator*> nested_message_generators_;