POSIX: re-enable strict aliasing

build/common.gypi

 # Copyright (c) 2012 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.
 
 # IMPORTANT:
 # Please don't directly include this file if you are building via gyp_chromium,
 # since gyp_chromium is automatically forcing its inclusion.
 {
   # Variables expected to be overriden on the GYP command line (-D) or by
   # ~/.gyp/include.gypi.
@@ skipping 2306 matching lines @@
             # so remove any existing warning-enabling flags like -Wall.
             'cflags!': [
               '-Wall',
               '-Wextra',
             ],
             'cflags_cc': [
               # Don't warn about hash_map in third-party code.
               '-Wno-deprecated',
             ],
             'cflags': [
+              # Do not assume the code is strict-aliasing-safe. This can induce
+              # strange crashes, and we ignore warnings in third-party code.
+              # The reference bug for this is http://crbug.com/32204 .
+              '-fno-strict-aliasing',
               # Don't warn about printf format problems.
               # This is off by default in gcc but on in Ubuntu's gcc(!).
               '-Wno-format',
             ],
             'cflags_cc!': [
               # TODO(fischman): remove this.
               # http://code.google.com/p/chromium/issues/detail?id=90453
               '-Wsign-compare',
             ]
           }],
@@ skipping 403 matching lines @@
           'werror%': '-Werror',
           'libraries_for_target%': '',
         },
         'defines': [
           '_FILE_OFFSET_BITS=64',
         ],
         'cflags': [
           '<(werror)',  # See note above about the werror variable.
           '-pthread',
           '-fno-exceptions',
-          '-fno-strict-aliasing',  # See http://crbug.com/32204
           '-Wall',
           # TODO(evan): turn this back on once all the builds work.
           # '-Wextra',
           # Don't warn about unused function params.  We use those everywhere.
           '-Wno-unused-parameter',
           # Don't warn about the "struct foo f = {0};" initialization pattern.
           '-Wno-missing-field-initializers',
           # Don't export any symbols (for example, to plugins we dlopen()).
           # Note: this is *required* to make some plugins work.
           '-fvisibility=hidden',
@@ skipping 1943 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',
   },
 }