Add ObjC helpers for Any WKT.

- Capture the ObjC prefix used when generating the the file.
- Track the containing type on descriptors.
- Mark descriptors where the message class name got a suffix added to it.
- Expose a fullName property on Descriptors.
- Add helpers for packing/unpacking Any messages.
- Bump the ObjC runtime version number. Since we added methods and invoke them
  in the generated code, ensure the code is running against a matching version.
  Otherwise, someone could compile against headers, but run with a framework
  that is older and get unknown selector failures.  This should trip clearer
  messaging.

Fixes https://github.com/google/protobuf/issues/1674

4 files changed, 62 insertions, 26 deletions

diff --git a/src/google/protobuf/compiler/objectivec/objectivec_file.cc b/src/google/protobuf/compiler/objectivec/objectivec_file.cc
index f70d4d5f..685ed56d 100644
--- a/src/google/protobuf/compiler/objectivec/objectivec_file.cc
+++ b/src/google/protobuf/compiler/objectivec/objectivec_file.cc
@@ -53,7 +53,7 @@ namespace {
 // This is also found in GPBBootstrap.h, and needs to be kept in sync.  It
 // is the version check done to ensure generated code works with the current
 // runtime being used.
-const int32 GOOGLE_PROTOBUF_OBJC_GEN_VERSION = 30001;
+const int32 GOOGLE_PROTOBUF_OBJC_GEN_VERSION = 30002;
 
 const char* kHeaderExtension = ".pbobjc.h";
 
@@ -463,19 +463,22 @@ void FileGenerator::GenerateSource(io::Printer *printer) {
 
   // File descriptor only needed if there are messages to use it.
   if (message_generators_.size() > 0) {
-    string syntax;
+    map<string, string> vars;
+    vars["root_class_name"] = root_class_name_;
+    vars["package"] = file_->package();
+    vars["objc_prefix"] = FileClassPrefix(file_);
     switch (file_->syntax()) {
       case FileDescriptor::SYNTAX_UNKNOWN:
-        syntax = "GPBFileSyntaxUnknown";
+        vars["syntax"] = "GPBFileSyntaxUnknown";
         break;
       case FileDescriptor::SYNTAX_PROTO2:
-        syntax = "GPBFileSyntaxProto2";
+        vars["syntax"] = "GPBFileSyntaxProto2";
         break;
       case FileDescriptor::SYNTAX_PROTO3:
-        syntax = "GPBFileSyntaxProto3";
+        vars["syntax"] = "GPBFileSyntaxProto3";
         break;
     }
-    printer->Print(
+    printer->Print(vars,
         "#pragma mark - $root_class_name$_FileDescriptor\n"
         "\n"
         "static GPBFileDescriptor *$root_class_name$_FileDescriptor(void) {\n"
@@ -483,16 +486,24 @@ void FileGenerator::GenerateSource(io::Printer *printer) {
         "  // about thread safety of the singleton.\n"
         "  static GPBFileDescriptor *descriptor = NULL;\n"
         "  if (!descriptor) {\n"
-        "    GPBDebugCheckRuntimeVersion();\n"
-        "    descriptor = [[GPBFileDescriptor alloc] initWithPackage:@\"$package$\"\n"
-        "                                                     syntax:$syntax$];\n"
+        "    GPBDebugCheckRuntimeVersion();\n");
+    if (vars["objc_prefix"].size() > 0) {
+      printer->Print(
+          vars,
+          "    descriptor = [[GPBFileDescriptor alloc] initWithPackage:@\"$package$\"\n"
+          "                                                 objcPrefix:@\"$objc_prefix$\"\n"
+          "                                                     syntax:$syntax$];\n");
+    } else {
+      printer->Print(
+          vars,
+          "    descriptor = [[GPBFileDescriptor alloc] initWithPackage:@\"$package$\"\n"
+          "                                                     syntax:$syntax$];\n");
+    }
+    printer->Print(
         "  }\n"
         "  return descriptor;\n"
         "}\n"
-        "\n",
-        "root_class_name", root_class_name_,
-        "package", file_->package(),
-        "syntax", syntax);
+        "\n");
   }
 
   for (vector<EnumGenerator *>::iterator iter = enum_generators_.begin();
diff --git a/src/google/protobuf/compiler/objectivec/objectivec_helpers.cc b/src/google/protobuf/compiler/objectivec/objectivec_helpers.cc
index 847be983..2fe0016a 100644
--- a/src/google/protobuf/compiler/objectivec/objectivec_helpers.cc
+++ b/src/google/protobuf/compiler/objectivec/objectivec_helpers.cc
@@ -210,10 +210,14 @@ const char* const kReservedWordList[] = {
 hash_set<string> kReservedWords =
     MakeWordsMap(kReservedWordList, GOOGLE_ARRAYSIZE(kReservedWordList));
 
-string SanitizeNameForObjC(const string& input, const string& extension) {
+string SanitizeNameForObjC(const string& input,
+                           const string& extension,
+                           string* out_suffix_added) {
   if (kReservedWords.count(input) > 0) {
+    if (out_suffix_added) *out_suffix_added = extension;
     return input + extension;
   }
+  if (out_suffix_added) out_suffix_added->clear();
   return input;
 }
 
@@ -308,6 +312,12 @@ string BaseFileName(const FileDescriptor* file) {
   return basename;
 }
 
+string FileClassPrefix(const FileDescriptor* file) {
+  // Default is empty string, no need to check has_objc_class_prefix.
+  string result = file->options().objc_class_prefix();
+  return result;
+}
+
 string FilePath(const FileDescriptor* file) {
   string output;
   string basename;
@@ -338,19 +348,13 @@ string FilePathBasename(const FileDescriptor* file) {
   return output;
 }
 
-string FileClassPrefix(const FileDescriptor* file) {
-  // Default is empty string, no need to check has_objc_class_prefix.
-  string result = file->options().objc_class_prefix();
-  return result;
-}
-
 string FileClassName(const FileDescriptor* file) {
   string name = FileClassPrefix(file);
   name += UnderscoresToCamelCase(StripProto(BaseFileName(file)), true);
   name += "Root";
   // There aren't really any reserved words that end in "Root", but playing
   // it safe and checking.
-  return SanitizeNameForObjC(name, "_RootClass");
+  return SanitizeNameForObjC(name, "_RootClass", NULL);
 }
 
 string ClassNameWorker(const Descriptor* descriptor) {
@@ -372,11 +376,15 @@ string ClassNameWorker(const EnumDescriptor* descriptor) {
 }
 
 string ClassName(const Descriptor* descriptor) {
+  return ClassName(descriptor, NULL);
+}
+
+string ClassName(const Descriptor* descriptor, string* out_suffix_added) {
   // 1. Message names are used as is (style calls for CamelCase, trust it).
   // 2. Check for reserved word at the very end and then suffix things.
   string prefix = FileClassPrefix(descriptor->file());
   string name = ClassNameWorker(descriptor);
-  return SanitizeNameForObjC(prefix + name, "_Class");
+  return SanitizeNameForObjC(prefix + name, "_Class", out_suffix_added);
 }
 
 string EnumName(const EnumDescriptor* descriptor) {
@@ -390,7 +398,7 @@ string EnumName(const EnumDescriptor* descriptor) {
   //    yields Fixed_Class, Fixed_Size.
   string name = FileClassPrefix(descriptor->file());
   name += ClassNameWorker(descriptor);
-  return SanitizeNameForObjC(name, "_Enum");
+  return SanitizeNameForObjC(name, "_Enum", NULL);
 }
 
 string EnumValueName(const EnumValueDescriptor* descriptor) {
@@ -405,7 +413,7 @@ string EnumValueName(const EnumValueDescriptor* descriptor) {
   const string& name = class_name + "_" + value_str;
   // There aren't really any reserved words with an underscore and a leading
   // capital letter, but playing it safe and checking.
-  return SanitizeNameForObjC(name, "_Value");
+  return SanitizeNameForObjC(name, "_Value", NULL);
 }
 
 string EnumValueShortName(const EnumValueDescriptor* descriptor) {
@@ -442,7 +450,7 @@ string UnCamelCaseEnumShortName(const string& name) {
 string ExtensionMethodName(const FieldDescriptor* descriptor) {
   const string& name = NameFromFieldDescriptor(descriptor);
   const string& result = UnderscoresToCamelCase(name, false);
-  return SanitizeNameForObjC(result, "_Extension");
+  return SanitizeNameForObjC(result, "_Extension", NULL);
 }
 
 string FieldName(const FieldDescriptor* field) {
@@ -457,7 +465,7 @@ string FieldName(const FieldDescriptor* field) {
       result += "_p";
     }
   }
-  return SanitizeNameForObjC(result, "_p");
+  return SanitizeNameForObjC(result, "_p", NULL);
 }
 
 string FieldNameCapitalized(const FieldDescriptor* field) {
diff --git a/src/google/protobuf/compiler/objectivec/objectivec_helpers.h b/src/google/protobuf/compiler/objectivec/objectivec_helpers.h
index b05983df..022b7a1b 100644
--- a/src/google/protobuf/compiler/objectivec/objectivec_helpers.h
+++ b/src/google/protobuf/compiler/objectivec/objectivec_helpers.h
@@ -67,6 +67,9 @@ bool IsRetainedName(const string& name);
 // handling under ARC.
 bool IsInitName(const string& name);
 
+// Gets the objc_class_prefix.
+string FileClassPrefix(const FileDescriptor* file);
+
 // Gets the path of the file we're going to generate (sans the .pb.h
 // extension).  The path will be dependent on the objectivec package
 // declared in the proto package.
@@ -83,6 +86,7 @@ string FileClassName(const FileDescriptor* file);
 // These return the fully-qualified class name corresponding to the given
 // descriptor.
 string ClassName(const Descriptor* descriptor);
+string ClassName(const Descriptor* descriptor, string* out_suffix_added);
 string EnumName(const EnumDescriptor* descriptor);
 
 // Returns the fully-qualified name of the enum value corresponding to the
diff --git a/src/google/protobuf/compiler/objectivec/objectivec_message.cc b/src/google/protobuf/compiler/objectivec/objectivec_message.cc
index 822da893..7c5fe311 100644
--- a/src/google/protobuf/compiler/objectivec/objectivec_message.cc
+++ b/src/google/protobuf/compiler/objectivec/objectivec_message.cc
@@ -579,6 +579,19 @@ void MessageGenerator::GenerateSource(io::Printer* printer) {
           "    [localDescriptor setupExtensionRanges:ranges\n"
           "                                    count:(uint32_t)(sizeof(ranges) / sizeof(GPBExtensionRange))];\n");
     }
+    if (descriptor_->containing_type() != NULL) {
+      string parent_class_name = ClassName(descriptor_->containing_type());
+      printer->Print(
+          "    [localDescriptor setupContainingMessageClassName:GPBStringifySymbol($parent_name$)];\n",
+          "parent_name", parent_class_name);
+    }
+    string suffix_added;
+    ClassName(descriptor_, &suffix_added);
+    if (suffix_added.size() > 0) {
+      printer->Print(
+          "    [localDescriptor setupMessageClassNameSuffix:@\"$suffix$\"];\n",
+          "suffix", suffix_added);
+    }
     printer->Print(
         "    NSAssert(descriptor == nil, @\"Startup recursed!\");\n"
         "    descriptor = localDescriptor;\n"