[ObjC] Generation changes around proto3 optional.

- Bump the version marker in the generated code.
- Set the flag to say clear on zero is known.
- Set clear on zero for proto3 optional fields that aren't tagged as optional.
- Also tweak the call from some C generated code to use different apis with
  better validation.
- Mark the ObjC generator as supporting the proto3 optional feature.
- Regenerate the WKTs to get the new flags.

objectivec/GPBAny.pbobjc.h

@@ -17,10 +17,10 @@
  #import "GPBRootObject.h"
 #endif
 
-#if GOOGLE_PROTOBUF_OBJC_VERSION < 30003
+#if GOOGLE_PROTOBUF_OBJC_VERSION < 30004
 #error This file was generated by a newer version of protoc which is incompatible with your Protocol Buffer library sources.
 #endif
-#if 30003 < GOOGLE_PROTOBUF_OBJC_MIN_SUPPORTED_VERSION
+#if 30004 < GOOGLE_PROTOBUF_OBJC_MIN_SUPPORTED_VERSION
 #error This file was generated by an older version of protoc which is incompatible with your Protocol Buffer library sources.
 #endif
 

objectivec/GPBAny.pbobjc.m

@@ -72,7 +72,7 @@ typedef struct GPBAny__storage_ {
         .number = GPBAny_FieldNumber_TypeURL,
         .hasIndex = 0,
         .offset = (uint32_t)offsetof(GPBAny__storage_, typeURL),
-        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldTextFormatNameCustom),
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldTextFormatNameCustom | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeString,
       },
       {
@@ -81,7 +81,7 @@ typedef struct GPBAny__storage_ {
         .number = GPBAny_FieldNumber_Value,
         .hasIndex = 1,
         .offset = (uint32_t)offsetof(GPBAny__storage_, value),
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeBytes,
       },
     };
@@ -92,7 +92,7 @@ typedef struct GPBAny__storage_ {
                                         fields:fields
                                     fieldCount:(uint32_t)(sizeof(fields) / sizeof(GPBMessageFieldDescription))
                                    storageSize:sizeof(GPBAny__storage_)
-                                         flags:GPBDescriptorInitializationFlag_UsesClassRefs];
+                                         flags:(GPBDescriptorInitializationFlags)(GPBDescriptorInitializationFlag_UsesClassRefs | GPBDescriptorInitializationFlag_Proto3OptionalKnown)];
 #if !GPBOBJC_SKIP_MESSAGE_TEXTFORMAT_EXTRAS
     static const char *extraTextFormatInfo =
         "\001\001\004\241!!\000";

objectivec/GPBApi.pbobjc.h

@@ -17,10 +17,10 @@
  #import "GPBRootObject.h"
 #endif
 
-#if GOOGLE_PROTOBUF_OBJC_VERSION < 30003
+#if GOOGLE_PROTOBUF_OBJC_VERSION < 30004
 #error This file was generated by a newer version of protoc which is incompatible with your Protocol Buffer library sources.
 #endif
-#if 30003 < GOOGLE_PROTOBUF_OBJC_MIN_SUPPORTED_VERSION
+#if 30004 < GOOGLE_PROTOBUF_OBJC_MIN_SUPPORTED_VERSION
 #error This file was generated by an older version of protoc which is incompatible with your Protocol Buffer library sources.
 #endif
 

objectivec/GPBApi.pbobjc.m

@@ -96,7 +96,7 @@ typedef struct GPBApi__storage_ {
         .number = GPBApi_FieldNumber_Name,
         .hasIndex = 0,
         .offset = (uint32_t)offsetof(GPBApi__storage_, name),
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeString,
       },
       {
@@ -123,7 +123,7 @@ typedef struct GPBApi__storage_ {
         .number = GPBApi_FieldNumber_Version,
         .hasIndex = 1,
         .offset = (uint32_t)offsetof(GPBApi__storage_, version),
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeString,
       },
       {
@@ -150,7 +150,7 @@ typedef struct GPBApi__storage_ {
         .number = GPBApi_FieldNumber_Syntax,
         .hasIndex = 3,
         .offset = (uint32_t)offsetof(GPBApi__storage_, syntax),
-        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldHasEnumDescriptor),
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldHasEnumDescriptor | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeEnum,
       },
     };
@@ -161,7 +161,7 @@ typedef struct GPBApi__storage_ {
                                         fields:fields
                                     fieldCount:(uint32_t)(sizeof(fields) / sizeof(GPBMessageFieldDescription))
                                    storageSize:sizeof(GPBApi__storage_)
-                                         flags:GPBDescriptorInitializationFlag_UsesClassRefs];
+                                         flags:(GPBDescriptorInitializationFlags)(GPBDescriptorInitializationFlag_UsesClassRefs | GPBDescriptorInitializationFlag_Proto3OptionalKnown)];
     #if defined(DEBUG) && DEBUG
       NSAssert(descriptor == nil, @"Startup recursed!");
     #endif  // DEBUG
@@ -175,13 +175,13 @@ typedef struct GPBApi__storage_ {
 int32_t GPBApi_Syntax_RawValue(GPBApi *message) {
   GPBDescriptor *descriptor = [GPBApi descriptor];
   GPBFieldDescriptor *field = [descriptor fieldWithNumber:GPBApi_FieldNumber_Syntax];
-  return GPBGetMessageInt32Field(message, field);
+  return GPBGetMessageRawEnumField(message, field);
 }
 
 void SetGPBApi_Syntax_RawValue(GPBApi *message, int32_t value) {
   GPBDescriptor *descriptor = [GPBApi descriptor];
   GPBFieldDescriptor *field = [descriptor fieldWithNumber:GPBApi_FieldNumber_Syntax];
-  GPBSetInt32IvarWithFieldInternal(message, field, value, descriptor.file.syntax);
+  GPBSetMessageRawEnumField(message, field, value);
 }
 
 #pragma mark - GPBMethod
@@ -217,7 +217,7 @@ typedef struct GPBMethod__storage_ {
         .number = GPBMethod_FieldNumber_Name,
         .hasIndex = 0,
         .offset = (uint32_t)offsetof(GPBMethod__storage_, name),
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeString,
       },
       {
@@ -226,7 +226,7 @@ typedef struct GPBMethod__storage_ {
         .number = GPBMethod_FieldNumber_RequestTypeURL,
         .hasIndex = 1,
         .offset = (uint32_t)offsetof(GPBMethod__storage_, requestTypeURL),
-        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldTextFormatNameCustom),
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldTextFormatNameCustom | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeString,
       },
       {
@@ -235,7 +235,7 @@ typedef struct GPBMethod__storage_ {
         .number = GPBMethod_FieldNumber_RequestStreaming,
         .hasIndex = 2,
         .offset = 3,  // Stored in _has_storage_ to save space.
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeBool,
       },
       {
@@ -244,7 +244,7 @@ typedef struct GPBMethod__storage_ {
         .number = GPBMethod_FieldNumber_ResponseTypeURL,
         .hasIndex = 4,
         .offset = (uint32_t)offsetof(GPBMethod__storage_, responseTypeURL),
-        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldTextFormatNameCustom),
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldTextFormatNameCustom | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeString,
       },
       {
@@ -253,7 +253,7 @@ typedef struct GPBMethod__storage_ {
         .number = GPBMethod_FieldNumber_ResponseStreaming,
         .hasIndex = 5,
         .offset = 6,  // Stored in _has_storage_ to save space.
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeBool,
       },
       {
@@ -271,7 +271,7 @@ typedef struct GPBMethod__storage_ {
         .number = GPBMethod_FieldNumber_Syntax,
         .hasIndex = 7,
         .offset = (uint32_t)offsetof(GPBMethod__storage_, syntax),
-        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldHasEnumDescriptor),
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldHasEnumDescriptor | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeEnum,
       },
     };
@@ -282,7 +282,7 @@ typedef struct GPBMethod__storage_ {
                                         fields:fields
                                     fieldCount:(uint32_t)(sizeof(fields) / sizeof(GPBMessageFieldDescription))
                                    storageSize:sizeof(GPBMethod__storage_)
-                                         flags:GPBDescriptorInitializationFlag_UsesClassRefs];
+                                         flags:(GPBDescriptorInitializationFlags)(GPBDescriptorInitializationFlag_UsesClassRefs | GPBDescriptorInitializationFlag_Proto3OptionalKnown)];
 #if !GPBOBJC_SKIP_MESSAGE_TEXTFORMAT_EXTRAS
     static const char *extraTextFormatInfo =
         "\002\002\007\244\241!!\000\004\010\244\241!!\000";
@@ -301,13 +301,13 @@ typedef struct GPBMethod__storage_ {
 int32_t GPBMethod_Syntax_RawValue(GPBMethod *message) {
   GPBDescriptor *descriptor = [GPBMethod descriptor];
   GPBFieldDescriptor *field = [descriptor fieldWithNumber:GPBMethod_FieldNumber_Syntax];
-  return GPBGetMessageInt32Field(message, field);
+  return GPBGetMessageRawEnumField(message, field);
 }
 
 void SetGPBMethod_Syntax_RawValue(GPBMethod *message, int32_t value) {
   GPBDescriptor *descriptor = [GPBMethod descriptor];
   GPBFieldDescriptor *field = [descriptor fieldWithNumber:GPBMethod_FieldNumber_Syntax];
-  GPBSetInt32IvarWithFieldInternal(message, field, value, descriptor.file.syntax);
+  GPBSetMessageRawEnumField(message, field, value);
 }
 
 #pragma mark - GPBMixin
@@ -335,7 +335,7 @@ typedef struct GPBMixin__storage_ {
         .number = GPBMixin_FieldNumber_Name,
         .hasIndex = 0,
         .offset = (uint32_t)offsetof(GPBMixin__storage_, name),
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeString,
       },
       {
@@ -344,7 +344,7 @@ typedef struct GPBMixin__storage_ {
         .number = GPBMixin_FieldNumber_Root,
         .hasIndex = 1,
         .offset = (uint32_t)offsetof(GPBMixin__storage_, root),
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeString,
       },
     };
@@ -355,7 +355,7 @@ typedef struct GPBMixin__storage_ {
                                         fields:fields
                                     fieldCount:(uint32_t)(sizeof(fields) / sizeof(GPBMessageFieldDescription))
                                    storageSize:sizeof(GPBMixin__storage_)
-                                         flags:GPBDescriptorInitializationFlag_UsesClassRefs];
+                                         flags:(GPBDescriptorInitializationFlags)(GPBDescriptorInitializationFlag_UsesClassRefs | GPBDescriptorInitializationFlag_Proto3OptionalKnown)];
     #if defined(DEBUG) && DEBUG
       NSAssert(descriptor == nil, @"Startup recursed!");
     #endif  // DEBUG

objectivec/GPBBootstrap.h

@@ -132,7 +132,7 @@
 // Current library runtime version.
 // - Gets bumped when the runtime makes changes to the interfaces between the
 //   generated code and runtime (things added/removed, etc).
-#define GOOGLE_PROTOBUF_OBJC_VERSION 30003
+#define GOOGLE_PROTOBUF_OBJC_VERSION 30004
 
 // Minimum runtime version supported for compiling/running against.
 // - Gets changed when support for the older generated code is dropped.

objectivec/GPBDuration.pbobjc.h

@@ -17,10 +17,10 @@
  #import "GPBRootObject.h"
 #endif
 
-#if GOOGLE_PROTOBUF_OBJC_VERSION < 30003
+#if GOOGLE_PROTOBUF_OBJC_VERSION < 30004
 #error This file was generated by a newer version of protoc which is incompatible with your Protocol Buffer library sources.
 #endif
-#if 30003 < GOOGLE_PROTOBUF_OBJC_MIN_SUPPORTED_VERSION
+#if 30004 < GOOGLE_PROTOBUF_OBJC_MIN_SUPPORTED_VERSION
 #error This file was generated by an older version of protoc which is incompatible with your Protocol Buffer library sources.
 #endif
 

objectivec/GPBDuration.pbobjc.m

@@ -72,7 +72,7 @@ typedef struct GPBDuration__storage_ {
         .number = GPBDuration_FieldNumber_Seconds,
         .hasIndex = 0,
         .offset = (uint32_t)offsetof(GPBDuration__storage_, seconds),
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeInt64,
       },
       {
@@ -81,7 +81,7 @@ typedef struct GPBDuration__storage_ {
         .number = GPBDuration_FieldNumber_Nanos,
         .hasIndex = 1,
         .offset = (uint32_t)offsetof(GPBDuration__storage_, nanos),
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeInt32,
       },
     };
@@ -92,7 +92,7 @@ typedef struct GPBDuration__storage_ {
                                         fields:fields
                                     fieldCount:(uint32_t)(sizeof(fields) / sizeof(GPBMessageFieldDescription))
                                    storageSize:sizeof(GPBDuration__storage_)
-                                         flags:GPBDescriptorInitializationFlag_UsesClassRefs];
+                                         flags:(GPBDescriptorInitializationFlags)(GPBDescriptorInitializationFlag_UsesClassRefs | GPBDescriptorInitializationFlag_Proto3OptionalKnown)];
     #if defined(DEBUG) && DEBUG
       NSAssert(descriptor == nil, @"Startup recursed!");
     #endif  // DEBUG

objectivec/GPBEmpty.pbobjc.h

@@ -17,10 +17,10 @@
  #import "GPBRootObject.h"
 #endif
 
-#if GOOGLE_PROTOBUF_OBJC_VERSION < 30003
+#if GOOGLE_PROTOBUF_OBJC_VERSION < 30004
 #error This file was generated by a newer version of protoc which is incompatible with your Protocol Buffer library sources.
 #endif
-#if 30003 < GOOGLE_PROTOBUF_OBJC_MIN_SUPPORTED_VERSION
+#if 30004 < GOOGLE_PROTOBUF_OBJC_MIN_SUPPORTED_VERSION
 #error This file was generated by an older version of protoc which is incompatible with your Protocol Buffer library sources.
 #endif
 

objectivec/GPBEmpty.pbobjc.m

@@ -68,7 +68,7 @@ typedef struct GPBEmpty__storage_ {
                                         fields:NULL
                                     fieldCount:0
                                    storageSize:sizeof(GPBEmpty__storage_)
-                                         flags:GPBDescriptorInitializationFlag_UsesClassRefs];
+                                         flags:(GPBDescriptorInitializationFlags)(GPBDescriptorInitializationFlag_UsesClassRefs | GPBDescriptorInitializationFlag_Proto3OptionalKnown)];
     #if defined(DEBUG) && DEBUG
       NSAssert(descriptor == nil, @"Startup recursed!");
     #endif  // DEBUG

objectivec/GPBFieldMask.pbobjc.h

@@ -17,10 +17,10 @@
  #import "GPBRootObject.h"
 #endif
 
-#if GOOGLE_PROTOBUF_OBJC_VERSION < 30003
+#if GOOGLE_PROTOBUF_OBJC_VERSION < 30004
 #error This file was generated by a newer version of protoc which is incompatible with your Protocol Buffer library sources.
 #endif
-#if 30003 < GOOGLE_PROTOBUF_OBJC_MIN_SUPPORTED_VERSION
+#if 30004 < GOOGLE_PROTOBUF_OBJC_MIN_SUPPORTED_VERSION
 #error This file was generated by an older version of protoc which is incompatible with your Protocol Buffer library sources.
 #endif
 

objectivec/GPBFieldMask.pbobjc.m

@@ -81,7 +81,7 @@ typedef struct GPBFieldMask__storage_ {
                                         fields:fields
                                     fieldCount:(uint32_t)(sizeof(fields) / sizeof(GPBMessageFieldDescription))
                                    storageSize:sizeof(GPBFieldMask__storage_)
-                                         flags:GPBDescriptorInitializationFlag_UsesClassRefs];
+                                         flags:(GPBDescriptorInitializationFlags)(GPBDescriptorInitializationFlag_UsesClassRefs | GPBDescriptorInitializationFlag_Proto3OptionalKnown)];
     #if defined(DEBUG) && DEBUG
       NSAssert(descriptor == nil, @"Startup recursed!");
     #endif  // DEBUG

objectivec/GPBSourceContext.pbobjc.h

@@ -17,10 +17,10 @@
  #import "GPBRootObject.h"
 #endif
 
-#if GOOGLE_PROTOBUF_OBJC_VERSION < 30003
+#if GOOGLE_PROTOBUF_OBJC_VERSION < 30004
 #error This file was generated by a newer version of protoc which is incompatible with your Protocol Buffer library sources.
 #endif
-#if 30003 < GOOGLE_PROTOBUF_OBJC_MIN_SUPPORTED_VERSION
+#if 30004 < GOOGLE_PROTOBUF_OBJC_MIN_SUPPORTED_VERSION
 #error This file was generated by an older version of protoc which is incompatible with your Protocol Buffer library sources.
 #endif
 

objectivec/GPBSourceContext.pbobjc.m

@@ -70,7 +70,7 @@ typedef struct GPBSourceContext__storage_ {
         .number = GPBSourceContext_FieldNumber_FileName,
         .hasIndex = 0,
         .offset = (uint32_t)offsetof(GPBSourceContext__storage_, fileName),
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeString,
       },
     };
@@ -81,7 +81,7 @@ typedef struct GPBSourceContext__storage_ {
                                         fields:fields
                                     fieldCount:(uint32_t)(sizeof(fields) / sizeof(GPBMessageFieldDescription))
                                    storageSize:sizeof(GPBSourceContext__storage_)
-                                         flags:GPBDescriptorInitializationFlag_UsesClassRefs];
+                                         flags:(GPBDescriptorInitializationFlags)(GPBDescriptorInitializationFlag_UsesClassRefs | GPBDescriptorInitializationFlag_Proto3OptionalKnown)];
     #if defined(DEBUG) && DEBUG
       NSAssert(descriptor == nil, @"Startup recursed!");
     #endif  // DEBUG

objectivec/GPBStruct.pbobjc.h

@@ -17,10 +17,10 @@
  #import "GPBRootObject.h"
 #endif
 
-#if GOOGLE_PROTOBUF_OBJC_VERSION < 30003
+#if GOOGLE_PROTOBUF_OBJC_VERSION < 30004
 #error This file was generated by a newer version of protoc which is incompatible with your Protocol Buffer library sources.
 #endif
-#if 30003 < GOOGLE_PROTOBUF_OBJC_MIN_SUPPORTED_VERSION
+#if 30004 < GOOGLE_PROTOBUF_OBJC_MIN_SUPPORTED_VERSION
 #error This file was generated by an older version of protoc which is incompatible with your Protocol Buffer library sources.
 #endif
 

objectivec/GPBStruct.pbobjc.m

@@ -126,7 +126,7 @@ typedef struct GPBStruct__storage_ {
                                         fields:fields
                                     fieldCount:(uint32_t)(sizeof(fields) / sizeof(GPBMessageFieldDescription))
                                    storageSize:sizeof(GPBStruct__storage_)
-                                         flags:GPBDescriptorInitializationFlag_UsesClassRefs];
+                                         flags:(GPBDescriptorInitializationFlags)(GPBDescriptorInitializationFlag_UsesClassRefs | GPBDescriptorInitializationFlag_Proto3OptionalKnown)];
     #if defined(DEBUG) && DEBUG
       NSAssert(descriptor == nil, @"Startup recursed!");
     #endif  // DEBUG
@@ -226,7 +226,7 @@ typedef struct GPBValue__storage_ {
                                         fields:fields
                                     fieldCount:(uint32_t)(sizeof(fields) / sizeof(GPBMessageFieldDescription))
                                    storageSize:sizeof(GPBValue__storage_)
-                                         flags:GPBDescriptorInitializationFlag_UsesClassRefs];
+                                         flags:(GPBDescriptorInitializationFlags)(GPBDescriptorInitializationFlag_UsesClassRefs | GPBDescriptorInitializationFlag_Proto3OptionalKnown)];
     static const char *oneofs[] = {
       "kind",
     };
@@ -246,19 +246,19 @@ typedef struct GPBValue__storage_ {
 int32_t GPBValue_NullValue_RawValue(GPBValue *message) {
   GPBDescriptor *descriptor = [GPBValue descriptor];
   GPBFieldDescriptor *field = [descriptor fieldWithNumber:GPBValue_FieldNumber_NullValue];
-  return GPBGetMessageInt32Field(message, field);
+  return GPBGetMessageRawEnumField(message, field);
 }
 
 void SetGPBValue_NullValue_RawValue(GPBValue *message, int32_t value) {
   GPBDescriptor *descriptor = [GPBValue descriptor];
   GPBFieldDescriptor *field = [descriptor fieldWithNumber:GPBValue_FieldNumber_NullValue];
-  GPBSetInt32IvarWithFieldInternal(message, field, value, descriptor.file.syntax);
+  GPBSetMessageRawEnumField(message, field, value);
 }
 
 void GPBValue_ClearKindOneOfCase(GPBValue *message) {
   GPBDescriptor *descriptor = [GPBValue descriptor];
   GPBOneofDescriptor *oneof = [descriptor.oneofs objectAtIndex:0];
-  GPBMaybeClearOneof(message, oneof, -1, 0);
+  GPBClearOneof(message, oneof);
 }
 #pragma mark - GPBListValue
 
@@ -294,7 +294,7 @@ typedef struct GPBListValue__storage_ {
                                         fields:fields
                                     fieldCount:(uint32_t)(sizeof(fields) / sizeof(GPBMessageFieldDescription))
                                    storageSize:sizeof(GPBListValue__storage_)
-                                         flags:GPBDescriptorInitializationFlag_UsesClassRefs];
+                                         flags:(GPBDescriptorInitializationFlags)(GPBDescriptorInitializationFlag_UsesClassRefs | GPBDescriptorInitializationFlag_Proto3OptionalKnown)];
     #if defined(DEBUG) && DEBUG
       NSAssert(descriptor == nil, @"Startup recursed!");
     #endif  // DEBUG

objectivec/GPBTimestamp.pbobjc.h

@@ -17,10 +17,10 @@
  #import "GPBRootObject.h"
 #endif
 
-#if GOOGLE_PROTOBUF_OBJC_VERSION < 30003
+#if GOOGLE_PROTOBUF_OBJC_VERSION < 30004
 #error This file was generated by a newer version of protoc which is incompatible with your Protocol Buffer library sources.
 #endif
-#if 30003 < GOOGLE_PROTOBUF_OBJC_MIN_SUPPORTED_VERSION
+#if 30004 < GOOGLE_PROTOBUF_OBJC_MIN_SUPPORTED_VERSION
 #error This file was generated by an older version of protoc which is incompatible with your Protocol Buffer library sources.
 #endif
 

objectivec/GPBTimestamp.pbobjc.m

@@ -72,7 +72,7 @@ typedef struct GPBTimestamp__storage_ {
         .number = GPBTimestamp_FieldNumber_Seconds,
         .hasIndex = 0,
         .offset = (uint32_t)offsetof(GPBTimestamp__storage_, seconds),
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeInt64,
       },
       {
@@ -81,7 +81,7 @@ typedef struct GPBTimestamp__storage_ {
         .number = GPBTimestamp_FieldNumber_Nanos,
         .hasIndex = 1,
         .offset = (uint32_t)offsetof(GPBTimestamp__storage_, nanos),
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeInt32,
       },
     };
@@ -92,7 +92,7 @@ typedef struct GPBTimestamp__storage_ {
                                         fields:fields
                                     fieldCount:(uint32_t)(sizeof(fields) / sizeof(GPBMessageFieldDescription))
                                    storageSize:sizeof(GPBTimestamp__storage_)
-                                         flags:GPBDescriptorInitializationFlag_UsesClassRefs];
+                                         flags:(GPBDescriptorInitializationFlags)(GPBDescriptorInitializationFlag_UsesClassRefs | GPBDescriptorInitializationFlag_Proto3OptionalKnown)];
     #if defined(DEBUG) && DEBUG
       NSAssert(descriptor == nil, @"Startup recursed!");
     #endif  // DEBUG

objectivec/GPBType.pbobjc.h

@@ -17,10 +17,10 @@
  #import "GPBRootObject.h"
 #endif
 
-#if GOOGLE_PROTOBUF_OBJC_VERSION < 30003
+#if GOOGLE_PROTOBUF_OBJC_VERSION < 30004
 #error This file was generated by a newer version of protoc which is incompatible with your Protocol Buffer library sources.
 #endif
-#if 30003 < GOOGLE_PROTOBUF_OBJC_MIN_SUPPORTED_VERSION
+#if 30004 < GOOGLE_PROTOBUF_OBJC_MIN_SUPPORTED_VERSION
 #error This file was generated by an older version of protoc which is incompatible with your Protocol Buffer library sources.
 #endif
 

objectivec/GPBType.pbobjc.m

@@ -132,7 +132,7 @@ typedef struct GPBType__storage_ {
         .number = GPBType_FieldNumber_Name,
         .hasIndex = 0,
         .offset = (uint32_t)offsetof(GPBType__storage_, name),
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeString,
       },
       {
@@ -177,7 +177,7 @@ typedef struct GPBType__storage_ {
         .number = GPBType_FieldNumber_Syntax,
         .hasIndex = 2,
         .offset = (uint32_t)offsetof(GPBType__storage_, syntax),
-        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldHasEnumDescriptor),
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldHasEnumDescriptor | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeEnum,
       },
     };
@@ -188,7 +188,7 @@ typedef struct GPBType__storage_ {
                                         fields:fields
                                     fieldCount:(uint32_t)(sizeof(fields) / sizeof(GPBMessageFieldDescription))
                                    storageSize:sizeof(GPBType__storage_)
-                                         flags:GPBDescriptorInitializationFlag_UsesClassRefs];
+                                         flags:(GPBDescriptorInitializationFlags)(GPBDescriptorInitializationFlag_UsesClassRefs | GPBDescriptorInitializationFlag_Proto3OptionalKnown)];
     #if defined(DEBUG) && DEBUG
       NSAssert(descriptor == nil, @"Startup recursed!");
     #endif  // DEBUG
@@ -202,13 +202,13 @@ typedef struct GPBType__storage_ {
 int32_t GPBType_Syntax_RawValue(GPBType *message) {
   GPBDescriptor *descriptor = [GPBType descriptor];
   GPBFieldDescriptor *field = [descriptor fieldWithNumber:GPBType_FieldNumber_Syntax];
-  return GPBGetMessageInt32Field(message, field);
+  return GPBGetMessageRawEnumField(message, field);
 }
 
 void SetGPBType_Syntax_RawValue(GPBType *message, int32_t value) {
   GPBDescriptor *descriptor = [GPBType descriptor];
   GPBFieldDescriptor *field = [descriptor fieldWithNumber:GPBType_FieldNumber_Syntax];
-  GPBSetInt32IvarWithFieldInternal(message, field, value, descriptor.file.syntax);
+  GPBSetMessageRawEnumField(message, field, value);
 }
 
 #pragma mark - GPBField
@@ -251,7 +251,7 @@ typedef struct GPBField__storage_ {
         .number = GPBField_FieldNumber_Kind,
         .hasIndex = 0,
         .offset = (uint32_t)offsetof(GPBField__storage_, kind),
-        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldHasEnumDescriptor),
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldHasEnumDescriptor | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeEnum,
       },
       {
@@ -260,7 +260,7 @@ typedef struct GPBField__storage_ {
         .number = GPBField_FieldNumber_Cardinality,
         .hasIndex = 1,
         .offset = (uint32_t)offsetof(GPBField__storage_, cardinality),
-        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldHasEnumDescriptor),
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldHasEnumDescriptor | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeEnum,
       },
       {
@@ -269,7 +269,7 @@ typedef struct GPBField__storage_ {
         .number = GPBField_FieldNumber_Number,
         .hasIndex = 2,
         .offset = (uint32_t)offsetof(GPBField__storage_, number),
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeInt32,
       },
       {
@@ -278,7 +278,7 @@ typedef struct GPBField__storage_ {
         .number = GPBField_FieldNumber_Name,
         .hasIndex = 3,
         .offset = (uint32_t)offsetof(GPBField__storage_, name),
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeString,
       },
       {
@@ -287,7 +287,7 @@ typedef struct GPBField__storage_ {
         .number = GPBField_FieldNumber_TypeURL,
         .hasIndex = 4,
         .offset = (uint32_t)offsetof(GPBField__storage_, typeURL),
-        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldTextFormatNameCustom),
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldTextFormatNameCustom | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeString,
       },
       {
@@ -296,7 +296,7 @@ typedef struct GPBField__storage_ {
         .number = GPBField_FieldNumber_OneofIndex,
         .hasIndex = 5,
         .offset = (uint32_t)offsetof(GPBField__storage_, oneofIndex),
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeInt32,
       },
       {
@@ -305,7 +305,7 @@ typedef struct GPBField__storage_ {
         .number = GPBField_FieldNumber_Packed,
         .hasIndex = 6,
         .offset = 7,  // Stored in _has_storage_ to save space.
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeBool,
       },
       {
@@ -323,7 +323,7 @@ typedef struct GPBField__storage_ {
         .number = GPBField_FieldNumber_JsonName,
         .hasIndex = 8,
         .offset = (uint32_t)offsetof(GPBField__storage_, jsonName),
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeString,
       },
       {
@@ -332,7 +332,7 @@ typedef struct GPBField__storage_ {
         .number = GPBField_FieldNumber_DefaultValue,
         .hasIndex = 9,
         .offset = (uint32_t)offsetof(GPBField__storage_, defaultValue),
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeString,
       },
     };
@@ -343,7 +343,7 @@ typedef struct GPBField__storage_ {
                                         fields:fields
                                     fieldCount:(uint32_t)(sizeof(fields) / sizeof(GPBMessageFieldDescription))
                                    storageSize:sizeof(GPBField__storage_)
-                                         flags:GPBDescriptorInitializationFlag_UsesClassRefs];
+                                         flags:(GPBDescriptorInitializationFlags)(GPBDescriptorInitializationFlag_UsesClassRefs | GPBDescriptorInitializationFlag_Proto3OptionalKnown)];
 #if !GPBOBJC_SKIP_MESSAGE_TEXTFORMAT_EXTRAS
     static const char *extraTextFormatInfo =
         "\001\006\004\241!!\000";
@@ -362,25 +362,25 @@ typedef struct GPBField__storage_ {
 int32_t GPBField_Kind_RawValue(GPBField *message) {
   GPBDescriptor *descriptor = [GPBField descriptor];
   GPBFieldDescriptor *field = [descriptor fieldWithNumber:GPBField_FieldNumber_Kind];
-  return GPBGetMessageInt32Field(message, field);
+  return GPBGetMessageRawEnumField(message, field);
 }
 
 void SetGPBField_Kind_RawValue(GPBField *message, int32_t value) {
   GPBDescriptor *descriptor = [GPBField descriptor];
   GPBFieldDescriptor *field = [descriptor fieldWithNumber:GPBField_FieldNumber_Kind];
-  GPBSetInt32IvarWithFieldInternal(message, field, value, descriptor.file.syntax);
+  GPBSetMessageRawEnumField(message, field, value);
 }
 
 int32_t GPBField_Cardinality_RawValue(GPBField *message) {
   GPBDescriptor *descriptor = [GPBField descriptor];
   GPBFieldDescriptor *field = [descriptor fieldWithNumber:GPBField_FieldNumber_Cardinality];
-  return GPBGetMessageInt32Field(message, field);
+  return GPBGetMessageRawEnumField(message, field);
 }
 
 void SetGPBField_Cardinality_RawValue(GPBField *message, int32_t value) {
   GPBDescriptor *descriptor = [GPBField descriptor];
   GPBFieldDescriptor *field = [descriptor fieldWithNumber:GPBField_FieldNumber_Cardinality];
-  GPBSetInt32IvarWithFieldInternal(message, field, value, descriptor.file.syntax);
+  GPBSetMessageRawEnumField(message, field, value);
 }
 
 #pragma mark - Enum GPBField_Kind
@@ -528,7 +528,7 @@ typedef struct GPBEnum__storage_ {
         .number = GPBEnum_FieldNumber_Name,
         .hasIndex = 0,
         .offset = (uint32_t)offsetof(GPBEnum__storage_, name),
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeString,
       },
       {
@@ -564,7 +564,7 @@ typedef struct GPBEnum__storage_ {
         .number = GPBEnum_FieldNumber_Syntax,
         .hasIndex = 2,
         .offset = (uint32_t)offsetof(GPBEnum__storage_, syntax),
-        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldHasEnumDescriptor),
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldHasEnumDescriptor | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeEnum,
       },
     };
@@ -575,7 +575,7 @@ typedef struct GPBEnum__storage_ {
                                         fields:fields
                                     fieldCount:(uint32_t)(sizeof(fields) / sizeof(GPBMessageFieldDescription))
                                    storageSize:sizeof(GPBEnum__storage_)
-                                         flags:GPBDescriptorInitializationFlag_UsesClassRefs];
+                                         flags:(GPBDescriptorInitializationFlags)(GPBDescriptorInitializationFlag_UsesClassRefs | GPBDescriptorInitializationFlag_Proto3OptionalKnown)];
     #if defined(DEBUG) && DEBUG
       NSAssert(descriptor == nil, @"Startup recursed!");
     #endif  // DEBUG
@@ -589,13 +589,13 @@ typedef struct GPBEnum__storage_ {
 int32_t GPBEnum_Syntax_RawValue(GPBEnum *message) {
   GPBDescriptor *descriptor = [GPBEnum descriptor];
   GPBFieldDescriptor *field = [descriptor fieldWithNumber:GPBEnum_FieldNumber_Syntax];
-  return GPBGetMessageInt32Field(message, field);
+  return GPBGetMessageRawEnumField(message, field);
 }
 
 void SetGPBEnum_Syntax_RawValue(GPBEnum *message, int32_t value) {
   GPBDescriptor *descriptor = [GPBEnum descriptor];
   GPBFieldDescriptor *field = [descriptor fieldWithNumber:GPBEnum_FieldNumber_Syntax];
-  GPBSetInt32IvarWithFieldInternal(message, field, value, descriptor.file.syntax);
+  GPBSetMessageRawEnumField(message, field, value);
 }
 
 #pragma mark - GPBEnumValue
@@ -625,7 +625,7 @@ typedef struct GPBEnumValue__storage_ {
         .number = GPBEnumValue_FieldNumber_Name,
         .hasIndex = 0,
         .offset = (uint32_t)offsetof(GPBEnumValue__storage_, name),
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeString,
       },
       {
@@ -634,7 +634,7 @@ typedef struct GPBEnumValue__storage_ {
         .number = GPBEnumValue_FieldNumber_Number,
         .hasIndex = 1,
         .offset = (uint32_t)offsetof(GPBEnumValue__storage_, number),
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeInt32,
       },
       {
@@ -654,7 +654,7 @@ typedef struct GPBEnumValue__storage_ {
                                         fields:fields
                                     fieldCount:(uint32_t)(sizeof(fields) / sizeof(GPBMessageFieldDescription))
                                    storageSize:sizeof(GPBEnumValue__storage_)
-                                         flags:GPBDescriptorInitializationFlag_UsesClassRefs];
+                                         flags:(GPBDescriptorInitializationFlags)(GPBDescriptorInitializationFlag_UsesClassRefs | GPBDescriptorInitializationFlag_Proto3OptionalKnown)];
     #if defined(DEBUG) && DEBUG
       NSAssert(descriptor == nil, @"Startup recursed!");
     #endif  // DEBUG
@@ -690,7 +690,7 @@ typedef struct GPBOption__storage_ {
         .number = GPBOption_FieldNumber_Name,
         .hasIndex = 0,
         .offset = (uint32_t)offsetof(GPBOption__storage_, name),
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeString,
       },
       {
@@ -710,7 +710,7 @@ typedef struct GPBOption__storage_ {
                                         fields:fields
                                     fieldCount:(uint32_t)(sizeof(fields) / sizeof(GPBMessageFieldDescription))
                                    storageSize:sizeof(GPBOption__storage_)
-                                         flags:GPBDescriptorInitializationFlag_UsesClassRefs];
+                                         flags:(GPBDescriptorInitializationFlags)(GPBDescriptorInitializationFlag_UsesClassRefs | GPBDescriptorInitializationFlag_Proto3OptionalKnown)];
     #if defined(DEBUG) && DEBUG
       NSAssert(descriptor == nil, @"Startup recursed!");
     #endif  // DEBUG

objectivec/GPBWrappers.pbobjc.h

@@ -17,10 +17,10 @@
  #import "GPBRootObject.h"
 #endif
 
-#if GOOGLE_PROTOBUF_OBJC_VERSION < 30003
+#if GOOGLE_PROTOBUF_OBJC_VERSION < 30004
 #error This file was generated by a newer version of protoc which is incompatible with your Protocol Buffer library sources.
 #endif
-#if 30003 < GOOGLE_PROTOBUF_OBJC_MIN_SUPPORTED_VERSION
+#if 30004 < GOOGLE_PROTOBUF_OBJC_MIN_SUPPORTED_VERSION
 #error This file was generated by an older version of protoc which is incompatible with your Protocol Buffer library sources.
 #endif
 

objectivec/GPBWrappers.pbobjc.m

@@ -70,7 +70,7 @@ typedef struct GPBDoubleValue__storage_ {
         .number = GPBDoubleValue_FieldNumber_Value,
         .hasIndex = 0,
         .offset = (uint32_t)offsetof(GPBDoubleValue__storage_, value),
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeDouble,
       },
     };
@@ -81,7 +81,7 @@ typedef struct GPBDoubleValue__storage_ {
                                         fields:fields
                                     fieldCount:(uint32_t)(sizeof(fields) / sizeof(GPBMessageFieldDescription))
                                    storageSize:sizeof(GPBDoubleValue__storage_)
-                                         flags:GPBDescriptorInitializationFlag_UsesClassRefs];
+                                         flags:(GPBDescriptorInitializationFlags)(GPBDescriptorInitializationFlag_UsesClassRefs | GPBDescriptorInitializationFlag_Proto3OptionalKnown)];
     #if defined(DEBUG) && DEBUG
       NSAssert(descriptor == nil, @"Startup recursed!");
     #endif  // DEBUG
@@ -115,7 +115,7 @@ typedef struct GPBFloatValue__storage_ {
         .number = GPBFloatValue_FieldNumber_Value,
         .hasIndex = 0,
         .offset = (uint32_t)offsetof(GPBFloatValue__storage_, value),
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeFloat,
       },
     };
@@ -126,7 +126,7 @@ typedef struct GPBFloatValue__storage_ {
                                         fields:fields
                                     fieldCount:(uint32_t)(sizeof(fields) / sizeof(GPBMessageFieldDescription))
                                    storageSize:sizeof(GPBFloatValue__storage_)
-                                         flags:GPBDescriptorInitializationFlag_UsesClassRefs];
+                                         flags:(GPBDescriptorInitializationFlags)(GPBDescriptorInitializationFlag_UsesClassRefs | GPBDescriptorInitializationFlag_Proto3OptionalKnown)];
     #if defined(DEBUG) && DEBUG
       NSAssert(descriptor == nil, @"Startup recursed!");
     #endif  // DEBUG
@@ -160,7 +160,7 @@ typedef struct GPBInt64Value__storage_ {
         .number = GPBInt64Value_FieldNumber_Value,
         .hasIndex = 0,
         .offset = (uint32_t)offsetof(GPBInt64Value__storage_, value),
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeInt64,
       },
     };
@@ -171,7 +171,7 @@ typedef struct GPBInt64Value__storage_ {
                                         fields:fields
                                     fieldCount:(uint32_t)(sizeof(fields) / sizeof(GPBMessageFieldDescription))
                                    storageSize:sizeof(GPBInt64Value__storage_)
-                                         flags:GPBDescriptorInitializationFlag_UsesClassRefs];
+                                         flags:(GPBDescriptorInitializationFlags)(GPBDescriptorInitializationFlag_UsesClassRefs | GPBDescriptorInitializationFlag_Proto3OptionalKnown)];
     #if defined(DEBUG) && DEBUG
       NSAssert(descriptor == nil, @"Startup recursed!");
     #endif  // DEBUG
@@ -205,7 +205,7 @@ typedef struct GPBUInt64Value__storage_ {
         .number = GPBUInt64Value_FieldNumber_Value,
         .hasIndex = 0,
         .offset = (uint32_t)offsetof(GPBUInt64Value__storage_, value),
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeUInt64,
       },
     };
@@ -216,7 +216,7 @@ typedef struct GPBUInt64Value__storage_ {
                                         fields:fields
                                     fieldCount:(uint32_t)(sizeof(fields) / sizeof(GPBMessageFieldDescription))
                                    storageSize:sizeof(GPBUInt64Value__storage_)
-                                         flags:GPBDescriptorInitializationFlag_UsesClassRefs];
+                                         flags:(GPBDescriptorInitializationFlags)(GPBDescriptorInitializationFlag_UsesClassRefs | GPBDescriptorInitializationFlag_Proto3OptionalKnown)];
     #if defined(DEBUG) && DEBUG
       NSAssert(descriptor == nil, @"Startup recursed!");
     #endif  // DEBUG
@@ -250,7 +250,7 @@ typedef struct GPBInt32Value__storage_ {
         .number = GPBInt32Value_FieldNumber_Value,
         .hasIndex = 0,
         .offset = (uint32_t)offsetof(GPBInt32Value__storage_, value),
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeInt32,
       },
     };
@@ -261,7 +261,7 @@ typedef struct GPBInt32Value__storage_ {
                                         fields:fields
                                     fieldCount:(uint32_t)(sizeof(fields) / sizeof(GPBMessageFieldDescription))
                                    storageSize:sizeof(GPBInt32Value__storage_)
-                                         flags:GPBDescriptorInitializationFlag_UsesClassRefs];
+                                         flags:(GPBDescriptorInitializationFlags)(GPBDescriptorInitializationFlag_UsesClassRefs | GPBDescriptorInitializationFlag_Proto3OptionalKnown)];
     #if defined(DEBUG) && DEBUG
       NSAssert(descriptor == nil, @"Startup recursed!");
     #endif  // DEBUG
@@ -295,7 +295,7 @@ typedef struct GPBUInt32Value__storage_ {
         .number = GPBUInt32Value_FieldNumber_Value,
         .hasIndex = 0,
         .offset = (uint32_t)offsetof(GPBUInt32Value__storage_, value),
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeUInt32,
       },
     };
@@ -306,7 +306,7 @@ typedef struct GPBUInt32Value__storage_ {
                                         fields:fields
                                     fieldCount:(uint32_t)(sizeof(fields) / sizeof(GPBMessageFieldDescription))
                                    storageSize:sizeof(GPBUInt32Value__storage_)
-                                         flags:GPBDescriptorInitializationFlag_UsesClassRefs];
+                                         flags:(GPBDescriptorInitializationFlags)(GPBDescriptorInitializationFlag_UsesClassRefs | GPBDescriptorInitializationFlag_Proto3OptionalKnown)];
     #if defined(DEBUG) && DEBUG
       NSAssert(descriptor == nil, @"Startup recursed!");
     #endif  // DEBUG
@@ -339,7 +339,7 @@ typedef struct GPBBoolValue__storage_ {
         .number = GPBBoolValue_FieldNumber_Value,
         .hasIndex = 0,
         .offset = 1,  // Stored in _has_storage_ to save space.
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeBool,
       },
     };
@@ -350,7 +350,7 @@ typedef struct GPBBoolValue__storage_ {
                                         fields:fields
                                     fieldCount:(uint32_t)(sizeof(fields) / sizeof(GPBMessageFieldDescription))
                                    storageSize:sizeof(GPBBoolValue__storage_)
-                                         flags:GPBDescriptorInitializationFlag_UsesClassRefs];
+                                         flags:(GPBDescriptorInitializationFlags)(GPBDescriptorInitializationFlag_UsesClassRefs | GPBDescriptorInitializationFlag_Proto3OptionalKnown)];
     #if defined(DEBUG) && DEBUG
       NSAssert(descriptor == nil, @"Startup recursed!");
     #endif  // DEBUG
@@ -384,7 +384,7 @@ typedef struct GPBStringValue__storage_ {
         .number = GPBStringValue_FieldNumber_Value,
         .hasIndex = 0,
         .offset = (uint32_t)offsetof(GPBStringValue__storage_, value),
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeString,
       },
     };
@@ -395,7 +395,7 @@ typedef struct GPBStringValue__storage_ {
                                         fields:fields
                                     fieldCount:(uint32_t)(sizeof(fields) / sizeof(GPBMessageFieldDescription))
                                    storageSize:sizeof(GPBStringValue__storage_)
-                                         flags:GPBDescriptorInitializationFlag_UsesClassRefs];
+                                         flags:(GPBDescriptorInitializationFlags)(GPBDescriptorInitializationFlag_UsesClassRefs | GPBDescriptorInitializationFlag_Proto3OptionalKnown)];
     #if defined(DEBUG) && DEBUG
       NSAssert(descriptor == nil, @"Startup recursed!");
     #endif  // DEBUG
@@ -429,7 +429,7 @@ typedef struct GPBBytesValue__storage_ {
         .number = GPBBytesValue_FieldNumber_Value,
         .hasIndex = 0,
         .offset = (uint32_t)offsetof(GPBBytesValue__storage_, value),
-        .flags = GPBFieldOptional,
+        .flags = (GPBFieldFlags)(GPBFieldOptional | GPBFieldClearHasIvarOnZero),
         .dataType = GPBDataTypeBytes,
       },
     };
@@ -440,7 +440,7 @@ typedef struct GPBBytesValue__storage_ {
                                         fields:fields
                                     fieldCount:(uint32_t)(sizeof(fields) / sizeof(GPBMessageFieldDescription))
                                    storageSize:sizeof(GPBBytesValue__storage_)
-                                         flags:GPBDescriptorInitializationFlag_UsesClassRefs];
+                                         flags:(GPBDescriptorInitializationFlags)(GPBDescriptorInitializationFlag_UsesClassRefs | GPBDescriptorInitializationFlag_Proto3OptionalKnown)];
     #if defined(DEBUG) && DEBUG
       NSAssert(descriptor == nil, @"Startup recursed!");
     #endif  // DEBUG

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

@@ -104,13 +104,13 @@ void EnumFieldGenerator::GenerateCFunctionImplementations(
       "int32_t $owning_message_class$_$capitalized_name$_RawValue($owning_message_class$ *message) {\n"
       "  GPBDescriptor *descriptor = [$owning_message_class$ descriptor];\n"
       "  GPBFieldDescriptor *field = [descriptor fieldWithNumber:$field_number_name$];\n"
-      "  return GPBGetMessageInt32Field(message, field);\n"
+      "  return GPBGetMessageRawEnumField(message, field);\n"
       "}\n"
       "\n"
       "void Set$owning_message_class$_$capitalized_name$_RawValue($owning_message_class$ *message, int32_t value) {\n"
       "  GPBDescriptor *descriptor = [$owning_message_class$ descriptor];\n"
       "  GPBFieldDescriptor *field = [descriptor fieldWithNumber:$field_number_name$];\n"
-      "  GPBSetInt32IvarWithFieldInternal(message, field, value, descriptor.file.syntax);\n"
+      "  GPBSetMessageRawEnumField(message, field, value);\n"
       "}\n"
       "\n");
 }

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

@@ -91,6 +91,14 @@ void SetCommonFieldVariables(const FieldDescriptor* descriptor,
   if (descriptor->type() == FieldDescriptor::TYPE_ENUM) {
     field_flags.push_back("GPBFieldHasEnumDescriptor");
   }
+  // It will clear on a zero value if...
+  //  - not repeated/map
+  //  - doesn't have presence
+  bool clear_on_zero =
+      (!descriptor->is_repeated() && !descriptor->has_presence());
+  if (clear_on_zero) {
+    field_flags.push_back("GPBFieldClearHasIvarOnZero");
+  }
 
   (*variables)["fieldflags"] = BuildFlagsString(FLAGTYPE_FIELD, field_flags);
 

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

@@ -52,7 +52,7 @@ namespace objectivec {
 namespace {
 
 // This is also found in GPBBootstrap.h, and needs to be kept in sync.
-const int32 GOOGLE_PROTOBUF_OBJC_VERSION = 30003;
+const int32 GOOGLE_PROTOBUF_OBJC_VERSION = 30004;
 
 const char* kHeaderExtension = ".pbobjc.h";
 

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

@@ -57,15 +57,19 @@ class PROTOC_EXPORT ObjectiveCGenerator : public CodeGenerator {
   ObjectiveCGenerator& operator=(const ObjectiveCGenerator&) = delete;
 
   // implements CodeGenerator ----------------------------------------
-  bool HasGenerateAll() const;
+  bool HasGenerateAll() const override;
   bool Generate(const FileDescriptor* file,
                 const string& parameter,
                 GeneratorContext* context,
-                string* error) const;
+                string* error) const override;
   bool GenerateAll(const std::vector<const FileDescriptor*>& files,
                    const string& parameter,
                    GeneratorContext* context,
-                   string* error) const;
+                   string* error) const override;
+
+  uint64 GetSupportedFeatures() const override {
+    return FEATURE_PROTO3_OPTIONAL;
+  }
 };
 
 }  // namespace objectivec

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

@@ -516,6 +516,7 @@ void MessageGenerator::GenerateSource(io::Printer* printer) {
 
     std::vector<string> init_flags;
     init_flags.push_back("GPBDescriptorInitializationFlag_UsesClassRefs");
+    init_flags.push_back("GPBDescriptorInitializationFlag_Proto3OptionalKnown");
     if (need_defaults) {
       init_flags.push_back("GPBDescriptorInitializationFlag_FieldsWithDefault");
     }

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

@@ -122,7 +122,7 @@ void OneofGenerator::GenerateClearFunctionImplementation(io::Printer* printer) {
       "void $owning_message_class$_Clear$capitalized_name$OneOfCase($owning_message_class$ *message) {\n"
       "  GPBDescriptor *descriptor = [$owning_message_class$ descriptor];\n"
       "  GPBOneofDescriptor *oneof = [descriptor.oneofs objectAtIndex:$raw_index$];\n"
-      "  GPBMaybeClearOneof(message, oneof, $index$, 0);\n"
+      "  GPBClearOneof(message, oneof);\n"
       "}\n");
 }