Add support for a file listing expected package to objc prefixes for validation.

- Add a env var to pass a set of expected prefixes for validation.
- Report warnings/errors based on the expected prefixes vs. the data in the files compiled.
- Use some helpers from common directory.

objectivec/generate_descriptors_proto.sh

@@ -11,7 +11,6 @@ set -eu
 
 readonly ScriptDir=$(dirname "$(echo $0 | sed -e "s,^\([^/]\),$(pwd)/\1,")")
 readonly ProtoRootDir="${ScriptDir}/.."
-readonly ProtoC="${ProtoRootDir}/src/protoc"
 
 pushd "${ProtoRootDir}" > /dev/null
 
@@ -35,7 +34,7 @@ fi
 cd src
 make $@ protoc
 
-declare -a RUNTIME_PROTO_FILES=(\
+declare -a RUNTIME_PROTO_FILES=( \
   google/protobuf/any.proto \
   google/protobuf/api.proto \
   google/protobuf/descriptor.proto \
@@ -49,5 +48,3 @@ declare -a RUNTIME_PROTO_FILES=(\
   google/protobuf/wrappers.proto)
 
 ./protoc --objc_out="${ProtoRootDir}/objectivec" ${RUNTIME_PROTO_FILES[@]}
-
-popd > /dev/null

src/google/protobuf/compiler/objectivec/objectivec_file.cc

@@ -54,9 +54,6 @@ FileGenerator::FileGenerator(const FileDescriptor *file)
     : file_(file),
       root_class_name_(FileClassName(file)),
       is_public_dep_(false) {
-  // Validate the objc prefix.
-  ValidateObjCClassPrefix(file_);
-
   for (int i = 0; i < file_->enum_type_count(); i++) {
     EnumGenerator *generator = new EnumGenerator(file_->enum_type(i));
     enum_generators_.push_back(generator);

src/google/protobuf/compiler/objectivec/objectivec_generator.cc

@@ -57,8 +57,13 @@ bool ObjectiveCGenerator::Generate(const FileDescriptor* file,
     return false;
   }
 
-  FileGenerator file_generator(file);
+  // Validate the objc prefix/package pairing.
+  if (!ValidateObjCClassPrefix(file, error)) {
+    // *error will have been filled in.
+    return false;
+  }
 
+  FileGenerator file_generator(file);
   string filepath = FilePath(file);
 
   // Generate header.

src/google/protobuf/compiler/objectivec/objectivec_generator.h

@@ -53,6 +53,7 @@ class LIBPROTOC_EXPORT ObjectiveCGenerator : public CodeGenerator {
  private:
   GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(ObjectiveCGenerator);
 };
+
 }  // namespace objectivec
 }  // namespace compiler
 }  // namespace protobuf

src/google/protobuf/compiler/objectivec/objectivec_helpers.h

@@ -62,9 +62,6 @@ string FileName(const FileDescriptor* file);
 // declared in the proto package.
 string FilePath(const FileDescriptor* file);
 
-// Checks the prefix for a given file and outputs any warnings/errors needed.
-void ValidateObjCClassPrefix(const FileDescriptor* file);
-
 // Gets the name of the root class we'll generate in the file.  This class
 // is not meant for external consumption, but instead contains helpers that
 // the rest of the the classes need
@@ -145,6 +142,11 @@ string BuildFlagsString(const vector<string>& strings);
 
 string BuildCommentsString(const SourceLocation& location);
 
+// Checks the prefix for a given file and outputs any warnings needed, if
+// there are flat out errors, then out_error is filled in and the result is
+// false.
+bool ValidateObjCClassPrefix(const FileDescriptor* file, string *out_error);
+
 // Generate decode data needed for ObjC's GPBDecodeTextFormatName() to transform
 // the input into the the expected output.
 class LIBPROTOC_EXPORT TextFormatDecodeData {