Support the -Wassign-enum compiler flag. (#2085)

Support the -Wassign-enum compiler flag.

6 files changed, 47 insertions, 8 deletions

diff --git a/src/google/protobuf/compiler/objectivec/objectivec_extension.cc b/src/google/protobuf/compiler/objectivec/objectivec_extension.cc
index c0e7253a..d0de1eca 100644
--- a/src/google/protobuf/compiler/objectivec/objectivec_extension.cc
+++ b/src/google/protobuf/compiler/objectivec/objectivec_extension.cc
@@ -85,7 +85,7 @@ void ExtensionGenerator::GenerateStaticVariablesInitialization(
   if (descriptor_->containing_type()->options().message_set_wire_format())
     options.push_back("GPBExtensionSetWireFormat");
 
-  vars["options"] = BuildFlagsString(options);
+  vars["options"] = BuildFlagsString(FLAGTYPE_EXTENSION, options);
 
   ObjectiveCType objc_type = GetObjectiveCType(descriptor_);
   string singular_type;
diff --git a/src/google/protobuf/compiler/objectivec/objectivec_field.cc b/src/google/protobuf/compiler/objectivec/objectivec_field.cc
index d2a6e882..527b7c0c 100644
--- a/src/google/protobuf/compiler/objectivec/objectivec_field.cc
+++ b/src/google/protobuf/compiler/objectivec/objectivec_field.cc
@@ -93,7 +93,7 @@ void SetCommonFieldVariables(const FieldDescriptor* descriptor,
     field_flags.push_back("GPBFieldHasEnumDescriptor");
   }
 
-  (*variables)["fieldflags"] = BuildFlagsString(field_flags);
+  (*variables)["fieldflags"] = BuildFlagsString(FLAGTYPE_FIELD, field_flags);
 
   (*variables)["default"] = DefaultValue(descriptor);
   (*variables)["default_name"] = GPBGenericValueFieldName(descriptor);
diff --git a/src/google/protobuf/compiler/objectivec/objectivec_helpers.cc b/src/google/protobuf/compiler/objectivec/objectivec_helpers.cc
index 847be983..d85f0fea 100644
--- a/src/google/protobuf/compiler/objectivec/objectivec_helpers.cc
+++ b/src/google/protobuf/compiler/objectivec/objectivec_helpers.cc
@@ -262,6 +262,34 @@ bool IsSpecialName(const string& name, const string* special_names,
   return false;
 }
 
+string GetZeroEnumNameForFlagType(const FlagType flag_type) {
+  switch(flag_type) {
+    case FLAGTYPE_DESCRIPTOR_INITIALIZATION:
+      return "GPBDescriptorInitializationFlag_None";
+    case FLAGTYPE_EXTENSION:
+      return "GPBExtensionNone";
+    case FLAGTYPE_FIELD:
+      return "GPBFieldNone";
+    default:
+      GOOGLE_LOG(FATAL) << "Can't get here.";
+      return "0";
+  }
+}
+
+string GetEnumNameForFlagType(const FlagType flag_type) {
+  switch(flag_type) {
+    case FLAGTYPE_DESCRIPTOR_INITIALIZATION:
+      return "GPBDescriptorInitializationFlags";
+    case FLAGTYPE_EXTENSION:
+      return "GPBExtensionOptions";
+    case FLAGTYPE_FIELD:
+      return "GPBFieldFlags";
+    default:
+      GOOGLE_LOG(FATAL) << "Can't get here.";
+      return string();
+  }
+}
+
 }  // namespace
 
 // Escape C++ trigraphs by escaping question marks to \?
@@ -817,17 +845,21 @@ bool HasNonZeroDefaultValue(const FieldDescriptor* field) {
   return false;
 }
 
-string BuildFlagsString(const vector<string>& strings) {
+string BuildFlagsString(const FlagType flag_type,
+                        const vector<string>& strings) {
   if (strings.size() == 0) {
-    return "0";
+    return GetZeroEnumNameForFlagType(flag_type);
+  } else if (strings.size() == 1) {
+    return strings[0];
   }
-  string string;
+  string string("(" + GetEnumNameForFlagType(flag_type) + ")(");
   for (size_t i = 0; i != strings.size(); ++i) {
     if (i > 0) {
       string.append(" | ");
     }
     string.append(strings[i]);
   }
+  string.append(")");
   return string;
 }
 
diff --git a/src/google/protobuf/compiler/objectivec/objectivec_helpers.h b/src/google/protobuf/compiler/objectivec/objectivec_helpers.h
index b05983df..8f8f1d90 100644
--- a/src/google/protobuf/compiler/objectivec/objectivec_helpers.h
+++ b/src/google/protobuf/compiler/objectivec/objectivec_helpers.h
@@ -137,6 +137,12 @@ enum ObjectiveCType {
   OBJECTIVECTYPE_MESSAGE
 };
 
+enum FlagType {
+  FLAGTYPE_DESCRIPTOR_INITIALIZATION,
+  FLAGTYPE_EXTENSION,
+  FLAGTYPE_FIELD
+};
+
 template<class TDescriptor>
 string GetOptionalDeprecatedAttribute(const TDescriptor* descriptor, bool preSpace = true, bool postNewline = false) {
   if (descriptor->options().deprecated()) {
@@ -168,7 +174,7 @@ string GPBGenericValueFieldName(const FieldDescriptor* field);
 string DefaultValue(const FieldDescriptor* field);
 bool HasNonZeroDefaultValue(const FieldDescriptor* field);
 
-string BuildFlagsString(const vector<string>& strings);
+string BuildFlagsString(const FlagType type, const vector<string>& strings);
 
 // Builds HeaderDoc/appledoc style comments out of the comments in the .proto
 // file.
diff --git a/src/google/protobuf/compiler/objectivec/objectivec_map_field.cc b/src/google/protobuf/compiler/objectivec/objectivec_map_field.cc
index ac5d8aea..0bc9dc10 100644
--- a/src/google/protobuf/compiler/objectivec/objectivec_map_field.cc
+++ b/src/google/protobuf/compiler/objectivec/objectivec_map_field.cc
@@ -115,7 +115,7 @@ MapFieldGenerator::MapFieldGenerator(const FieldDescriptor* descriptor,
   if (value_field_flags.find("GPBFieldHasEnumDescriptor") != string::npos) {
     field_flags.push_back("GPBFieldHasEnumDescriptor");
   }
-  variables_["fieldflags"] = BuildFlagsString(field_flags);
+  variables_["fieldflags"] = BuildFlagsString(FLAGTYPE_FIELD, field_flags);
 
   ObjectiveCType value_objc_type = GetObjectiveCType(value_descriptor);
   const bool value_is_object_type =
diff --git a/src/google/protobuf/compiler/objectivec/objectivec_message.cc b/src/google/protobuf/compiler/objectivec/objectivec_message.cc
index 822da893..36537e43 100644
--- a/src/google/protobuf/compiler/objectivec/objectivec_message.cc
+++ b/src/google/protobuf/compiler/objectivec/objectivec_message.cc
@@ -521,7 +521,8 @@ void MessageGenerator::GenerateSource(io::Printer* printer) {
     if (descriptor_->options().message_set_wire_format()) {
       init_flags.push_back("GPBDescriptorInitializationFlag_WireFormat");
     }
-    vars["init_flags"] = BuildFlagsString(init_flags);
+    vars["init_flags"] = BuildFlagsString(FLAGTYPE_DESCRIPTOR_INITIALIZATION,
+                                          init_flags);
 
     printer->Print(
         vars,