Mac -fno-threadsafe-statics

build/common.gypi

 # Copyright (c) 2009 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.
 
 {
   'variables': {
     # .gyp files should set chromium_code to 1 if they build Chromium-specific
     # code, as opposed to external code.  This variable is used to control
     # such things as the set of warnings to enable, and whether warnings are
     # treated as errors.
@@ skipping 180 matching lines @@
          }],  # OS==win
         ],  # conditions for chrome_personalization
       }],  # chrome_personalization==1
       ['use_syncapi_stub==1', {
        'defines': ['COMPILING_SYNCAPI_STUB'],
       }],  # use_syncapi_stub==1
       ['coverage!=0', {
         'conditions': [
           ['OS=="mac"', {
             'xcode_settings': {
-              'GCC_INSTRUMENT_PROGRAM_FLOW_ARCS': 'YES',
-              'GCC_GENERATE_TEST_COVERAGE_FILES': 'YES',
+              'GCC_INSTRUMENT_PROGRAM_FLOW_ARCS': 'YES',  # -fprofile-arcs
+              'GCC_GENERATE_TEST_COVERAGE_FILES': 'YES',  # -ftest-coverage
             },
             # Add -lgcov for executables, not for static_libraries.
             # This is a delayed conditional.
             'target_conditions': [
               ['_type=="executable"', {
                 'xcode_settings': { 'OTHER_LDFLAGS': [ '-lgcov' ] },
               }],
             ],
           }],
           # Linux gyp (into scons) doesn't like target_conditions?
@@ skipping 25 matching lines @@
        # VCLinkerTool LinkIncremental values below:
        #   0 == default
        #   1 == /INCREMENTAL:NO
        #   2 == /INCREMENTAL
        # Debug links incremental, Release does not.
       'Debug': {
         'conditions': [
           [ 'OS=="mac"', {
             'xcode_settings': {
               'COPY_PHASE_STRIP': 'NO',
-              'GCC_OPTIMIZATION_LEVEL': '0',
+              'GCC_OPTIMIZATION_LEVEL': '0',  # -O0
             }
           }],
           [ 'OS=="win"', {
             'configuration_platform': 'Win32',
             'msvs_configuration_attributes': {
               'OutputDirectory': '$(SolutionDir)$(ConfigurationName)',
               'IntermediateDirectory': '$(OutDir)\\obj\\$(ProjectName)',
               'CharacterSet': '1',
             },
             'msvs_settings': {
@@ skipping 13 matching lines @@
           }],
         ],
       },
       'Release': {
         'defines': [
           'NDEBUG',
         ],
         'conditions': [
           [ 'OS=="mac"', {
             'xcode_settings': {
-              'DEAD_CODE_STRIPPING': 'YES',
+              'DEAD_CODE_STRIPPING': 'YES',  # -Wl,-dead_strip
               'conditions': [
                 ['mac_release_optimization != "UNSET"',
                   {'GCC_OPTIMIZATION_LEVEL': '<(mac_release_optimization)'}],
               ],
             }
           }],
           [ 'OS=="win" and msvs_use_common_release', {
             'configuration_platform': 'Win32',
             'msvs_props': ['release.vsprops'],
           }],
@@ skipping 256 matching lines @@
           # with % in variables that are intended to be set to different
           # values in different targets, like this one.
           'mac_real_dsym': 0,  # Fake .dSYMs are fine in most cases.
           # Release defaults to the Xcode optimization default, this var
           # lets you force the value.
           'mac_release_optimization%': 'UNSET'
         },
         'mac_bundle': 0,
         'xcode_settings': {
           'ALWAYS_SEARCH_USER_PATHS': 'NO',
-          'GCC_C_LANGUAGE_STANDARD': 'c99',
-          'GCC_CW_ASM_SYNTAX': 'NO',
-          'GCC_DYNAMIC_NO_PIC': 'NO',
-          'GCC_ENABLE_CPP_EXCEPTIONS': 'NO',
-          'GCC_ENABLE_CPP_RTTI': 'NO',
-          'GCC_ENABLE_PASCAL_STRINGS': 'NO',
-          'GCC_INLINES_ARE_PRIVATE_EXTERN': 'YES',
-          'GCC_OBJC_CALL_CXX_CDTORS': 'YES',
-          'GCC_SYMBOLS_PRIVATE_EXTERN': 'YES',
-          'GCC_TREAT_WARNINGS_AS_ERRORS': 'YES',
+          'GCC_C_LANGUAGE_STANDARD': 'c99',         # -std=c99
+          'GCC_CW_ASM_SYNTAX': 'NO',                # No -fasm-blocks
+          'GCC_DYNAMIC_NO_PIC': 'NO',               # No -mdynamic-no-pic
+                                                    # (Equivalent to -fPIC)
+          'GCC_ENABLE_CPP_EXCEPTIONS': 'NO',        # -fno-exceptions
+          'GCC_ENABLE_CPP_RTTI': 'NO',              # -fno-rtti
+          'GCC_ENABLE_PASCAL_STRINGS': 'NO',        # No -mpascal-strings
+          'GCC_INLINES_ARE_PRIVATE_EXTERN': 'YES',  # -fvisibility-inlines-hidden
+          'GCC_OBJC_CALL_CXX_CDTORS': 'YES',        # -fobjc-call-cxx-cdtors
+          'GCC_SYMBOLS_PRIVATE_EXTERN': 'YES',      # -fvisibility=hidden
+          'GCC_THREADSAFE_STATICS': 'NO',           # -fno-threadsafe-statics
+          'GCC_TREAT_WARNINGS_AS_ERRORS': 'YES',    # -Werror
           'GCC_VERSION': '4.2',
-          'GCC_WARN_ABOUT_MISSING_NEWLINE': 'YES',
-          'MACOSX_DEPLOYMENT_TARGET': '10.5',
-          'PREBINDING': 'NO',
-          'SDKROOT': 'macosx10.5',
+          'GCC_WARN_ABOUT_MISSING_NEWLINE': 'YES',  # -Wnewline-eof
+          'MACOSX_DEPLOYMENT_TARGET': '10.5',       # -mmacosx-version-min=10.5
+          'PREBINDING': 'NO',                       # No -Wl,-prebind
+          'SDKROOT': 'macosx10.5',                  # -isysroot
           'USE_HEADERMAP': 'NO',
           'WARNING_CFLAGS': ['-Wall', '-Wendif-labels'],
           'conditions': [
             ['chromium_mac_pch', {'GCC_PRECOMPILE_PREFIX_HEADER': 'YES'},
                                  {'GCC_PRECOMPILE_PREFIX_HEADER': 'NO'}],
           ],
         },
         'target_conditions': [
           ['_type!="static_library"', {
             'xcode_settings': {'OTHER_LDFLAGS': ['-Wl,-search_paths_first']},
@@ skipping 175 matching lines @@
     # settings in target dicts.  SYMROOT is a special case, because many other
     # Xcode variables depend on it, including variables such as
     # PROJECT_DERIVED_FILE_DIR.  When a source group corresponding to something
     # like PROJECT_DERIVED_FILE_DIR is added to a project, in order for the
     # files to appear (when present) in the UI as actual files and not red
     # red "missing file" proxies, the correct path to PROJECT_DERIVED_FILE_DIR,
     # and therefore SYMROOT, needs to be set at the project level.
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }