Fix gyptest-xcode-gcc.py when using Xcode 5.0.2

test/mac/gyptest-xcode-gcc.py

Index: test/mac/gyptest-xcode-gcc.py
diff --git a/test/mac/gyptest-xcode-gcc.py b/test/mac/gyptest-xcode-gcc.py
index abd884897d527c668d0165bd1690df7ab78408f2..3082b9dcdc6bfb39ca07eb3e1da3d49e8a90bca8 100644
--- a/test/mac/gyptest-xcode-gcc.py
+++ b/test/mac/gyptest-xcode-gcc.py
@@ -11,11 +11,28 @@ Verifies that xcode-style GCC_... settings are handled properly.
 import TestGyp
 
 import os
+import subprocess
 import sys
 
 def IgnoreOutput(string, expected_string):
   return True
 
+def CompilerVersion(compiler):
+  stdout = subprocess.check_output([compiler, '-v'], stderr=subprocess.STDOUT)
+  return stdout.rstrip('\n')
+
+def CompilerSupportsWarnAboutInvalidOffsetOfMacro(test):
+  # With Xcode 5.0.2, gcc is a version of clang using different binary and
+  # include directories. It then behaves like clang and doesn't warn on
+  # invalid offsetofs (it silently ignore -Wno-invalid-offsetof).
+  if 'clang' in CompilerVersion('/usr/bin/gcc'):
+    return False
+  # TODO(thakis): This isn't really the right way to detect the compiler,
+  # Xcode has some embedded compiler, but it's a reliable proxy at least on
+  # the bots. The compiler is forced to gcc/g++ in the gyp file in a
+  # make_global_settings section for ninja and make.
+  return test.format != 'xcode' or os.readlink('/usr/bin/cc') != 'clang'

[Mark Mentovai, 2013/12/06 20:17:56]

I think that testing |'clang' in CompilerVersion('/usr/bin/gcc')| is a better
version of the os.readlink test, because it should detect both symbolic link and
non-symbolic-link installations of cc (or gcc) as clang. Can you simplify this
function?

[sdefresne, 2013/12/10 12:38:43]

Done.

+
 if sys.platform == 'darwin':
   test = TestGyp.TestGyp(formats=['ninja', 'make', 'xcode'])
 
@@ -30,11 +47,7 @@ if sys.platform == 'darwin':
 
   # clang doesn't warn on invalid offsetofs, it silently ignores
   # -Wno-invalid-offsetof.
-  # TODO(thakis): This isn't really the right way to detect the compiler,
-  # Xcode has some embedded compiler, but it's a reliable proxy at least on
-  # the bots. The compiler is forced to gcc/g++ in the gyp file in a
-  # make_global_settings section for ninja and make.
-  if test.format != 'xcode' or os.readlink('/usr/bin/cc') != 'clang':
+  if CompilerSupportsWarnAboutInvalidOffsetOfMacro(test):
     targets.append('warn_about_invalid_offsetof_macro')
 
   for target in targets: