clang support

build/common.gypi

 # Copyright (c) 2010 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': {
     # .gyp files or targets should set chromium_code to 1 if they build
@@ skipping 233 matching lines @@
     'msvs_debug_link_incremental%': '2',
 
     # This is the location of the sandbox binary. Chrome looks for this before
     # running the zygote process. If found, and SUID, it will be used to
     # sandbox the zygote process and, thus, all renderer processes.
     'linux_sandbox_path%': '',
 
     # Set this to true to enable SELinux support.
     'selinux%': 0,
 
+    # Set this to true when building with Clang.
+    # TODO: eventually clang should behave identically to gcc, and this
+    # won't be necessary.
+    'clang%': 0,
+
     # Override whether we should use Breakpad on Linux. I.e. for Chrome bot.
     'linux_breakpad%': 0,
     # And if we want to dump symbols for Breakpad-enabled builds.
     'linux_dump_symbols%': 0,
     # And if we want to strip the binary after dumping symbols.
     'linux_strip_binary%': 0,
     # Strip the test binaries needed for Linux reliability tests.
     'linux_strip_reliability_tests%': 0,
 
     # Enable TCMalloc.
@@ skipping 843 matching lines @@
             'target_conditions': [
               ['_toolset=="target"', {
                 'cflags': [
                   '--sysroot=<(sysroot)',
                 ],
                 'ldflags': [
                   '--sysroot=<(sysroot)',
                 ],
               }]]
           }],
+          ['clang==1', {
+            'cflags': [
+              # Don't warn about unused variables, due to a common pattern:
+              #   scoped_deleter unused_variable(&thing_to_delete);
+              '-Wno-unused-variable',
+              # Clang spots more unused functions.
+              '-Wno-unused-function',
+              # gtest confuses clang.
+              '-Wno-bool-conversions',
+              # Don't die on dtoa code that uses a char as an array index.
+              '-Wno-char-subscripts',
+            ],
+            'cflags!': [
+              # Clang doesn't seem to know know this flag.
+              '-mfpmath=sse',
+            ],
+          }],
           ['no_strict_aliasing==1', {
             'cflags': [
               '-fno-strict-aliasing',
             ],
           }],
           ['linux_breakpad==1', {
             'cflags': [ '-g' ],
             'defines': ['USE_LINUX_BREAKPAD'],
           }],
           ['linux_use_seccomp_sandbox==1 and buildtype!="Official"', {
@@ skipping 329 matching lines @@
     # and therefore SYMROOT, needs to be set at the project level.
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }
 
 # Local Variables:
 # tab-width:2
 # indent-tabs-mode:nil
 # End:
 # vim: set expandtab tabstop=2 shiftwidth=2: