Set CC to clang when GYP_DEFINES=clang=1.

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index 14e78d11b0d17b8227d7dc70c6b7c5df9f515c5a..23ccc7411609fbf147d4933370692840d500120c 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -1676,6 +1676,9 @@
                                  {'GCC_PRECOMPILE_PREFIX_HEADER': 'NO'}
             ],
             ['clang==1', {
+              'CC': '$(SOURCE_ROOT)/<(clang_dir)/clang',
+              'LDPLUSPLUS': '$(SOURCE_ROOT)/<(clang_dir)/clang++',

[Evan Martin, 2011/09/06 17:41:16]

Where does SOURCE_ROOT come from?

[Nico, 2011/09/06 17:47:08]

I think it's one of the many magic environment variables that xcode sets when
building, see
http://developer.apple.com/library/mac/#documentation/DeveloperTools/Referenc...

+              'GCC_VERSION': 'com.apple.compilers.llvm.clang.1_0',
               'WARNING_CFLAGS': [
                 '-Wheader-hygiene',
                 # Don't die on dtoa code that uses a char as an array index.
@@ -1703,6 +1706,13 @@
             }],
           ],
         },
+        'conditions': [
+          ['clang==1', {
+            'variables': {
+              'clang_dir': '../third_party/llvm-build/Release+Asserts/bin',
+            },
+          }],
+        ],
         'target_conditions': [
           ['_type!="static_library"', {
             'xcode_settings': {'OTHER_LDFLAGS': ['-Wl,-search_paths_first']},
@@ -2010,6 +2020,16 @@
         ],
       },
     }],
+    ['clang==1', {
+      'make_global_settings': [
+        ['CC', 'third_party/llvm-build/Release+Asserts/bin/clang'],
+        ['CXX', 'third_party/llvm-build/Release+Asserts/bin/clang++'],
+        ['LINK', 'third_party/llvm-build/Release+Asserts/bin/clang++'],

[Mark Mentovai, 2011/09/07 01:36:24]

This is fine for now.

We’ll need to split this up in the same way that Xcode does in order to migrate
the official build to make, so that make doesn’t link C-only programs as C++.

+        ['CC.host', '$(CC)'],
+        ['CXX.host', '$(CXX)'],
+        ['LINK.host', '$(LINK)'],
+      ],
+    }],
   ],
   'xcode_settings': {
     # DON'T ADD ANYTHING NEW TO THIS BLOCK UNLESS YOU REALLY REALLY NEED IT!