Don't #import the .m files.

As bazel folks are looking at getting auto generation of module maps going and
the importing of sources files causes issues there.  We were only do it to
hack around some of the apple linker behaviors around objc classes and
categories, but even that isn't complete and CocoaPods was already doing -ObjC,
and developers not using pods could have still needed it to ensure everything
was linked anyways; so drop the hack of importing sources.

Protobuf.podspec

@@ -18,18 +18,14 @@ Pod::Spec.new do |s|
   s.source_files = 'objectivec/*.{h,m}',
                    'objectivec/google/protobuf/Any.pbobjc.{h,m}',
                    'objectivec/google/protobuf/Api.pbobjc.{h,m}',
-                   'objectivec/google/protobuf/Duration.pbobjc.h',
+                   'objectivec/google/protobuf/Duration.pbobjc.{h,m}',
                    'objectivec/google/protobuf/Empty.pbobjc.{h,m}',
                    'objectivec/google/protobuf/FieldMask.pbobjc.{h,m}',
                    'objectivec/google/protobuf/SourceContext.pbobjc.{h,m}',
                    'objectivec/google/protobuf/Struct.pbobjc.{h,m}',
-                   'objectivec/google/protobuf/Timestamp.pbobjc.h',
+                   'objectivec/google/protobuf/Timestamp.pbobjc.{h,m}',
                    'objectivec/google/protobuf/Type.pbobjc.{h,m}',
                    'objectivec/google/protobuf/Wrappers.pbobjc.{h,m}'
-  # Timestamp.pbobjc.m and Duration.pbobjc.m are #imported by GPBWellKnownTypes.m. So we can't
-  # compile them (duplicate symbols), but we need them available for the importing:
-  s.preserve_paths = 'objectivec/google/protobuf/Duration.pbobjc.m',
-                     'objectivec/google/protobuf/Timestamp.pbobjc.m'
   # The following would cause duplicate symbol definitions. GPBProtocolBuffers is expected to be
   # left out, as it's an umbrella implementation file.
   s.exclude_files = 'objectivec/GPBProtocolBuffers.m'

objectivec/GPBDescriptor.m

@@ -756,8 +756,7 @@ uint32_t GPBFieldAlternateTag(GPBFieldDescriptor *self) {
   return NO;
 }
 
-- (BOOL)getValue:(int32_t *)outValue forEnumTextFormatName:(NSString *)textFormatName;
-{
+- (BOOL)getValue:(int32_t *)outValue forEnumTextFormatName:(NSString *)textFormatName {
     if (nameOffsets_ == NULL) [self calcValueNameOffsets];
 
     for (uint32_t i = 0; i < valueCount_; ++i) {

objectivec/GPBProtocolBuffers.m

@@ -54,15 +54,13 @@
 #import "GPBWellKnownTypes.m"
 #import "GPBWireFormat.m"
 
-// Duration and Timestamp are #imported into GPBWellKnownTypes.m to the
-// Objective C categories added will always be linked in with the classes.
 #import "google/protobuf/Any.pbobjc.m"
 #import "google/protobuf/Api.pbobjc.m"
-// #import "google/protobuf/Duration.pbobjc.m"
+#import "google/protobuf/Duration.pbobjc.m"
 #import "google/protobuf/Empty.pbobjc.m"
 #import "google/protobuf/FieldMask.pbobjc.m"
 #import "google/protobuf/SourceContext.pbobjc.m"
 #import "google/protobuf/Struct.pbobjc.m"
-// #import "google/protobuf/Timestamp.pbobjc.m"
+#import "google/protobuf/Timestamp.pbobjc.m"
 #import "google/protobuf/Type.pbobjc.m"
 #import "google/protobuf/Wrappers.pbobjc.m"

objectivec/GPBWellKnownTypes.m

@@ -32,8 +32,6 @@
 // the static library. If these were compiled separately, the category methods
 // below would be stripped by the linker.
 
-#import "google/protobuf/Timestamp.pbobjc.m"
-#import "google/protobuf/Duration.pbobjc.m"
 #import "GPBWellKnownTypes.h"
 
 static NSTimeInterval TimeIntervalSince1970FromSecondsAndNanos(int64_t seconds,

objectivec/ProtocolBuffers_OSX.xcodeproj/project.pbxproj

@@ -54,6 +54,8 @@
 		F4487C831AAF6AB300531423 /* GPBMessageTests+Merge.m in Sources */ = {isa = PBXBuildFile; fileRef = F4487C821AAF6AB300531423 /* GPBMessageTests+Merge.m */; };
 		F45C69CC16DFD08D0081955B /* GPBExtensionInternals.m in Sources */ = {isa = PBXBuildFile; fileRef = F45C69CB16DFD08D0081955B /* GPBExtensionInternals.m */; };
 		F45E57C71AE6DC6A000B7D99 /* text_format_map_unittest_data.txt in Resources */ = {isa = PBXBuildFile; fileRef = F45E57C61AE6DC6A000B7D99 /* text_format_map_unittest_data.txt */; };
+		F47476E51D21A524007C7B1A /* Duration.pbobjc.m in Sources */ = {isa = PBXBuildFile; fileRef = 8B4248D41A92826400BC1EC6 /* Duration.pbobjc.m */; };
+		F47476E61D21A524007C7B1A /* Timestamp.pbobjc.m in Sources */ = {isa = PBXBuildFile; fileRef = 8B4248D61A92826400BC1EC6 /* Timestamp.pbobjc.m */; };
 		F4B51B1E1BBC610700744318 /* GPBObjectiveCPlusPlusTest.mm in Sources */ = {isa = PBXBuildFile; fileRef = F4B51B1D1BBC610700744318 /* GPBObjectiveCPlusPlusTest.mm */; };
 		F4E675971B21D0000054530B /* Any.pbobjc.m in Sources */ = {isa = PBXBuildFile; fileRef = F4E675871B21D0000054530B /* Any.pbobjc.m */; };
 		F4E675991B21D0000054530B /* Api.pbobjc.m in Sources */ = {isa = PBXBuildFile; fileRef = F4E675891B21D0000054530B /* Api.pbobjc.m */; };
@@ -625,6 +627,7 @@
 				F4E6759D1B21D0000054530B /* FieldMask.pbobjc.m in Sources */,
 				7461B54C0F94FB4E00A0C422 /* GPBUnknownField.m in Sources */,
 				7461B5530F94FB4E00A0C422 /* GPBMessage.m in Sources */,
+				F47476E51D21A524007C7B1A /* Duration.pbobjc.m in Sources */,
 				7461B5610F94FB4E00A0C422 /* GPBUnknownFieldSet.m in Sources */,
 				7461B5630F94FB4E00A0C422 /* GPBUtilities.m in Sources */,
 				7461B5640F94FB4E00A0C422 /* GPBWireFormat.m in Sources */,
@@ -639,6 +642,7 @@
 				F4E675A31B21D0000054530B /* Type.pbobjc.m in Sources */,
 				F4E675A11B21D0000054530B /* Struct.pbobjc.m in Sources */,
 				F4E675A51B21D0000054530B /* Wrappers.pbobjc.m in Sources */,
+				F47476E61D21A524007C7B1A /* Timestamp.pbobjc.m in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -727,6 +731,7 @@
 				);
 				INFOPLIST_FILE = "Tests/UnitTests-Info.plist";
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/../Frameworks @loader_path/../Frameworks";
+				OTHER_LDFLAGS = "-ObjC";
 				PRODUCT_BUNDLE_IDENTIFIER = "com.yourcompany.${PRODUCT_NAME:identifier}";
 				PRODUCT_NAME = UnitTests;
 				SWIFT_OBJC_BRIDGING_HEADER = "Tests/UnitTests-Bridging-Header.h";
@@ -751,6 +756,7 @@
 				);
 				INFOPLIST_FILE = "Tests/UnitTests-Info.plist";
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/../Frameworks @loader_path/../Frameworks";
+				OTHER_LDFLAGS = "-ObjC";
 				PRODUCT_BUNDLE_IDENTIFIER = "com.yourcompany.${PRODUCT_NAME:identifier}";
 				PRODUCT_NAME = UnitTests;
 				SWIFT_OBJC_BRIDGING_HEADER = "Tests/UnitTests-Bridging-Header.h";

objectivec/ProtocolBuffers_iOS.xcodeproj/project.pbxproj

@@ -62,6 +62,8 @@
 		F4487C851AAF6AC500531423 /* GPBMessageTests+Merge.m in Sources */ = {isa = PBXBuildFile; fileRef = F4487C841AAF6AC500531423 /* GPBMessageTests+Merge.m */; };
 		F45C69CC16DFD08D0081955B /* GPBExtensionInternals.m in Sources */ = {isa = PBXBuildFile; fileRef = F45C69CB16DFD08D0081955B /* GPBExtensionInternals.m */; };
 		F45E57C91AE6DC98000B7D99 /* text_format_map_unittest_data.txt in Resources */ = {isa = PBXBuildFile; fileRef = F45E57C81AE6DC98000B7D99 /* text_format_map_unittest_data.txt */; };
+		F47476E91D21A537007C7B1A /* Duration.pbobjc.m in Sources */ = {isa = PBXBuildFile; fileRef = 8B4248DE1A929C7D00BC1EC6 /* Duration.pbobjc.m */; };
+		F47476EA1D21A537007C7B1A /* Timestamp.pbobjc.m in Sources */ = {isa = PBXBuildFile; fileRef = 8B4248E01A929C7D00BC1EC6 /* Timestamp.pbobjc.m */; };
 		F4B51B1C1BBC5C7100744318 /* GPBObjectiveCPlusPlusTest.mm in Sources */ = {isa = PBXBuildFile; fileRef = F4B51B1B1BBC5C7100744318 /* GPBObjectiveCPlusPlusTest.mm */; };
 		F4E675D01B21D1620054530B /* Any.pbobjc.m in Sources */ = {isa = PBXBuildFile; fileRef = F4E675B71B21D1440054530B /* Any.pbobjc.m */; };
 		F4E675D11B21D1620054530B /* Api.pbobjc.m in Sources */ = {isa = PBXBuildFile; fileRef = F4E675B91B21D1440054530B /* Api.pbobjc.m */; };
@@ -713,6 +715,7 @@
 				F4E675D31B21D1620054530B /* FieldMask.pbobjc.m in Sources */,
 				7461B54C0F94FB4E00A0C422 /* GPBUnknownField.m in Sources */,
 				7461B5530F94FB4E00A0C422 /* GPBMessage.m in Sources */,
+				F47476E91D21A537007C7B1A /* Duration.pbobjc.m in Sources */,
 				7461B5610F94FB4E00A0C422 /* GPBUnknownFieldSet.m in Sources */,
 				7461B5630F94FB4E00A0C422 /* GPBUtilities.m in Sources */,
 				7461B5640F94FB4E00A0C422 /* GPBWireFormat.m in Sources */,
@@ -727,6 +730,7 @@
 				F4E675D61B21D1620054530B /* Type.pbobjc.m in Sources */,
 				F4E675D51B21D1620054530B /* Struct.pbobjc.m in Sources */,
 				F4E675D71B21D1620054530B /* Wrappers.pbobjc.m in Sources */,
+				F47476EA1D21A537007C7B1A /* Timestamp.pbobjc.m in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -878,6 +882,7 @@
 					"$(inherited)",
 					"\"$(DEVELOPER_DIR)/usr/lib\"",
 				);
+				OTHER_LDFLAGS = "-ObjC";
 				PRODUCT_NAME = UnitTests;
 				SWIFT_OBJC_BRIDGING_HEADER = "Tests/UnitTests-Bridging-Header.h";
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
@@ -912,6 +917,7 @@
 					"$(inherited)",
 					"\"$(DEVELOPER_DIR)/usr/lib\"",
 				);
+				OTHER_LDFLAGS = "-ObjC";
 				PRODUCT_NAME = UnitTests;
 				SWIFT_OBJC_BRIDGING_HEADER = "Tests/UnitTests-Bridging-Header.h";
 				TARGETED_DEVICE_FAMILY = "1,2";