Componentize protobuf_lite

Several parts of chrome that use protobufs depend on the static library 'protobuf_lite' in third_party/protobuf. As more parts of chrome are pulled into their own components, we end up linking duplicate copies of protobuf_lite into each of them. This causes memory corruption errors due to protobuf's use of static variables to maintain state.

Componentizing protobuf_lite isn't as simple as changing its target type to '<(component)'. This is because there is a larger, more full-fledged version of protobuf in the target 'protobuf_full_do_not_use', which cannot be dynamically linked with the component protobuf_lite. This is because several classes declared in protobuf_lite are partially defined in protobuf_full_do_not_use, due to which we run into issues with dllexport/dllimport annotations.

The target 'protobuf_lite' is used as a dependency all over chrome, while the target 'protobuf_full_do_not_use' is used only in one place, where it is statically linked into the protobuf compiler executable 'protoc'.

This patch does the following:
1) Pulls out most of the target definitions of 'protobuf_lite' into a separate gypi file.
2) Defines protobuf export macros for all platforms in protobuf/stubs/common.h.
3) For the target 'protobuf_lite':
  - Changes the target type to '<(component)'.
  - Includes the contents of protobuf_lite.gypi.
  - Exports symbols via the LIBPROTOBUF_EXPORT macro.
  - Makes sure targets that consume it can import its symbols.
4) For the target 'protobuf_full_do_not_use':
  - Retains the target type of 'static_library'.
  - Includes the contents of protobuf_lite.gypi instead of depending on the target 'protobuf_lite'.

BUG=172800
TEST=Enable component builds and make sure all chrome targets build, and all tests run and pass.

Review URL: https://codereview.chromium.org/12090058

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@179806 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 112 insertions, 77 deletions

diff --git a/third_party/protobuf/README.chromium b/third_party/protobuf/README.chromium
index 7672411..4439bac 100644
--- a/third_party/protobuf/README.chromium
+++ b/third_party/protobuf/README.chromium
@@ -22,6 +22,10 @@ See r62331 for the patch.
 This code has been patched to ensure that files in the target protobuf_lite
 do not include headers from protobuf_full. See r173228 for the patch.
 
+This code has been patched to make the target protobuf_lite a component so that
+targets that depend on it can be componentized. See http://crbug.com/172800.
+TODO(rsimha): Add revision number here after CL is committed.
+
 Revisions r427 and r430 were cherry-picked from upstream.
 
 Cherry-pick patch from http://code.google.com/p/protobuf/issues/detail?id=425.
diff --git a/third_party/protobuf/protobuf.gyp b/third_party/protobuf/protobuf.gyp
index f9a624f..7c507c1 100644
--- a/third_party/protobuf/protobuf.gyp
+++ b/third_party/protobuf/protobuf.gyp
@@ -129,74 +129,23 @@
         # to your .proto file.
         {
           'target_name': 'protobuf_lite',
-          'type': 'static_library',
+          'type': '<(component)',
           'toolsets': ['host', 'target'],
-          'sources': [
-            'src/google/protobuf/stubs/atomicops.h',
-            'src/google/protobuf/stubs/atomicops_internals_arm_gcc.h',
-            'src/google/protobuf/stubs/atomicops_internals_atomicword_compat.h',
-            'src/google/protobuf/stubs/atomicops_internals_macosx.h',
-            'src/google/protobuf/stubs/atomicops_internals_mips_gcc.h',
-            'src/google/protobuf/stubs/atomicops_internals_x86_gcc.cc',
-            'src/google/protobuf/stubs/atomicops_internals_x86_gcc.h',
-            'src/google/protobuf/stubs/atomicops_internals_x86_msvc.cc',
-            'src/google/protobuf/stubs/atomicops_internals_x86_msvc.h',
-            'src/google/protobuf/stubs/common.h',
-            'src/google/protobuf/stubs/once.h',
-            'src/google/protobuf/stubs/platform_macros.h',
-            'src/google/protobuf/extension_set.h',
-            'src/google/protobuf/generated_message_util.h',
-            'src/google/protobuf/message_lite.h',
-            'src/google/protobuf/repeated_field.h',
-            'src/google/protobuf/unknown_field_set.cc',
-            'src/google/protobuf/unknown_field_set.h',
-            'src/google/protobuf/wire_format_lite.h',
-            'src/google/protobuf/wire_format_lite_inl.h',
-            'src/google/protobuf/io/coded_stream.h',
-            'src/google/protobuf/io/zero_copy_stream.h',
-            'src/google/protobuf/io/zero_copy_stream_impl_lite.h',
-
-            'src/google/protobuf/stubs/common.cc',
-            'src/google/protobuf/stubs/once.cc',
-            'src/google/protobuf/stubs/hash.h',
-            'src/google/protobuf/stubs/map-util.h',
-            'src/google/protobuf/stubs/stl_util-inl.h',
-            'src/google/protobuf/extension_set.cc',
-            'src/google/protobuf/generated_message_util.cc',
-            'src/google/protobuf/message_lite.cc',
-            'src/google/protobuf/repeated_field.cc',
-            'src/google/protobuf/wire_format_lite.cc',
-            'src/google/protobuf/io/coded_stream.cc',
-            'src/google/protobuf/io/coded_stream_inl.h',
-            'src/google/protobuf/io/zero_copy_stream.cc',
-            'src/google/protobuf/io/zero_copy_stream_impl_lite.cc',
-            '<(config_h_dir)/config.h',
+          'includes': [
+            'protobuf_lite.gypi',
           ],
-          'include_dirs': [
-            '<(config_h_dir)',
-            'src',
-          ],
-          # This macro must be defined to suppress the use of dynamic_cast<>,
-          # which requires RTTI.
+          # Required for component builds. See http://crbug.com/172800.
           'defines': [
-            'GOOGLE_PROTOBUF_NO_RTTI',
-            'GOOGLE_PROTOBUF_NO_STATIC_INITIALIZER',
+            'LIBPROTOBUF_EXPORTS',
+            'PROTOBUF_USE_DLLS',
           ],
-
           'direct_dependent_settings': {
-            'include_dirs': [
-              '<(config_h_dir)',
-              'src',
-            ],
             'defines': [
-              'GOOGLE_PROTOBUF_NO_RTTI',
-              'GOOGLE_PROTOBUF_NO_STATIC_INITIALIZER',
+              'PROTOBUF_USE_DLLS',
             ],
-            # TODO(jschuh): http://crbug.com/167187 size_t -> int.
-            'msvs_disabled_warnings': [ 4267 ],
           },
         },
-        # This is the full, heavy protobuf lib that's needed for c++ .proto's
+        # This is the full, heavy protobuf lib that's needed for c++ .protos
         # that don't specify the LITE_RUNTIME option.  The protocol
         # compiler itself (protoc) falls into that category.
         #
@@ -205,6 +154,9 @@
           'target_name': 'protobuf_full_do_not_use',
           'type': 'static_library',
           'toolsets': ['host','target'],
+          'includes': [
+            'protobuf_lite.gypi',
+          ],
           'sources': [
             'src/google/protobuf/descriptor.h',
             'src/google/protobuf/descriptor.pb.h',
@@ -250,12 +202,6 @@
             'src/google/protobuf/compiler/importer.cc',
             'src/google/protobuf/compiler/parser.cc',
           ],
-          'dependencies': [
-            'protobuf_lite',
-          ],
-          'export_dependent_settings': [
-            'protobuf_lite',
-          ],
         },
         {
           'target_name': 'protoc',
diff --git a/third_party/protobuf/protobuf_lite.gypi b/third_party/protobuf/protobuf_lite.gypi
new file mode 100644
index 0000000..e66d29f
--- /dev/null
+++ b/third_party/protobuf/protobuf_lite.gypi
@@ -0,0 +1,69 @@
+# Copyright 2013 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+{
+  'sources': [
+    'src/google/protobuf/stubs/atomicops.h',
+    'src/google/protobuf/stubs/atomicops_internals_arm_gcc.h',
+    'src/google/protobuf/stubs/atomicops_internals_atomicword_compat.h',
+    'src/google/protobuf/stubs/atomicops_internals_macosx.h',
+    'src/google/protobuf/stubs/atomicops_internals_mips_gcc.h',
+    'src/google/protobuf/stubs/atomicops_internals_x86_gcc.cc',
+    'src/google/protobuf/stubs/atomicops_internals_x86_gcc.h',
+    'src/google/protobuf/stubs/atomicops_internals_x86_msvc.cc',
+    'src/google/protobuf/stubs/atomicops_internals_x86_msvc.h',
+    'src/google/protobuf/stubs/common.h',
+    'src/google/protobuf/stubs/once.h',
+    'src/google/protobuf/stubs/platform_macros.h',
+    'src/google/protobuf/extension_set.h',
+    'src/google/protobuf/generated_message_util.h',
+    'src/google/protobuf/message_lite.h',
+    'src/google/protobuf/repeated_field.h',
+    'src/google/protobuf/unknown_field_set.cc',
+    'src/google/protobuf/unknown_field_set.h',
+    'src/google/protobuf/wire_format_lite.h',
+    'src/google/protobuf/wire_format_lite_inl.h',
+    'src/google/protobuf/io/coded_stream.h',
+    'src/google/protobuf/io/zero_copy_stream.h',
+    'src/google/protobuf/io/zero_copy_stream_impl_lite.h',
+
+    'src/google/protobuf/stubs/common.cc',
+    'src/google/protobuf/stubs/once.cc',
+    'src/google/protobuf/stubs/hash.h',
+    'src/google/protobuf/stubs/map-util.h',
+    'src/google/protobuf/stubs/stl_util-inl.h',
+    'src/google/protobuf/extension_set.cc',
+    'src/google/protobuf/generated_message_util.cc',
+    'src/google/protobuf/message_lite.cc',
+    'src/google/protobuf/repeated_field.cc',
+    'src/google/protobuf/wire_format_lite.cc',
+    'src/google/protobuf/io/coded_stream.cc',
+    'src/google/protobuf/io/coded_stream_inl.h',
+    'src/google/protobuf/io/zero_copy_stream.cc',
+    'src/google/protobuf/io/zero_copy_stream_impl_lite.cc',
+    '<(config_h_dir)/config.h',
+  ],
+  'include_dirs': [
+    '<(config_h_dir)',
+    'src',
+  ],
+  # This macro must be defined to suppress the use of dynamic_cast<>,
+  # which requires RTTI.
+  'defines': [
+    'GOOGLE_PROTOBUF_NO_RTTI',
+    'GOOGLE_PROTOBUF_NO_STATIC_INITIALIZER',
+  ],
+  'direct_dependent_settings': {
+    'include_dirs': [
+      '<(config_h_dir)',
+      'src',
+    ],
+    'defines': [
+      'GOOGLE_PROTOBUF_NO_RTTI',
+      'GOOGLE_PROTOBUF_NO_STATIC_INITIALIZER',
+    ],
+    # TODO(jschuh): http://crbug.com/167187 size_t -> int.
+    'msvs_disabled_warnings': [ 4267 ],
+  },
+}
diff --git a/third_party/protobuf/src/google/protobuf/stubs/common.h b/third_party/protobuf/src/google/protobuf/stubs/common.h
index 00af41a..cad22fa 100644
--- a/third_party/protobuf/src/google/protobuf/stubs/common.h
+++ b/third_party/protobuf/src/google/protobuf/stubs/common.h
@@ -85,18 +85,33 @@ namespace protobuf {
   TypeName(const TypeName&);                           \
   void operator=(const TypeName&)
 
-#if defined(_MSC_VER) && defined(PROTOBUF_USE_DLLS)
-  #ifdef LIBPROTOBUF_EXPORTS
-    #define LIBPROTOBUF_EXPORT __declspec(dllexport)
-  #else
-    #define LIBPROTOBUF_EXPORT __declspec(dllimport)
+// The macros defined below are required in order to make protobuf_lite a
+// component on all platforms. See http://crbug.com/172800.
+#if defined(COMPONENT_BUILD) && defined(PROTOBUF_USE_DLLS)
+  #if defined(_MSC_VER)
+    #ifdef LIBPROTOBUF_EXPORTS
+      #define LIBPROTOBUF_EXPORT __declspec(dllexport)
+    #else
+      #define LIBPROTOBUF_EXPORT __declspec(dllimport)
+    #endif
+    #ifdef LIBPROTOC_EXPORTS
+      #define LIBPROTOC_EXPORT   __declspec(dllexport)
+    #else
+      #define LIBPROTOC_EXPORT   __declspec(dllimport)
+    #endif
+  #else  // defined(_MSC_VER)
+    #ifdef LIBPROTOBUF_EXPORTS
+      #define LIBPROTOBUF_EXPORT __attribute__((visibility("default")))
+    #else
+      #define LIBPROTOBUF_EXPORT
+    #endif
+    #ifdef LIBPROTOC_EXPORTS
+      #define LIBPROTOC_EXPORT   __attribute__((visibility("default")))
+    #else
+      #define LIBPROTOC_EXPORT
+    #endif
   #endif
-  #ifdef LIBPROTOC_EXPORTS
-    #define LIBPROTOC_EXPORT   __declspec(dllexport)
-  #else
-    #define LIBPROTOC_EXPORT   __declspec(dllimport)
-  #endif
-#else
+#else  // defined(COMPONENT_BUILD) && defined(PROTOBUF_USE_DLLS)
   #define LIBPROTOBUF_EXPORT
   #define LIBPROTOC_EXPORT
 #endif
diff --git a/third_party/protobuf/src/google/protobuf/stubs/once.h b/third_party/protobuf/src/google/protobuf/stubs/once.h
index c8cbe24..ead86fb 100644
--- a/third_party/protobuf/src/google/protobuf/stubs/once.h
+++ b/third_party/protobuf/src/google/protobuf/stubs/once.h
@@ -118,7 +118,8 @@ typedef internal::AtomicWord ProtobufOnceType;
 
 #define GOOGLE_PROTOBUF_ONCE_INIT ::google::protobuf::ONCE_STATE_UNINITIALIZED
 
-void GoogleOnceInitImpl(ProtobufOnceType* once, Closure* closure);
+LIBPROTOBUF_EXPORT void GoogleOnceInitImpl(ProtobufOnceType* once,
+                                           Closure* closure);
 
 inline void GoogleOnceInit(ProtobufOnceType* once, void (*init_func)()) {
   if (internal::Acquire_Load(once) != ONCE_STATE_DONE) {