Make goma work on win GN builds.

build/toolchain/win/setup_toolchain.py

Index: build/toolchain/win/setup_toolchain.py
diff --git a/build/toolchain/win/setup_toolchain.py b/build/toolchain/win/setup_toolchain.py
index 42c3af1b6cd7e65d3e0641d680ecc9162952cbe1..7645ba79cf485a93773ec1c08248b31e86b732fd 100644
--- a/build/toolchain/win/setup_toolchain.py
+++ b/build/toolchain/win/setup_toolchain.py
@@ -53,7 +53,7 @@ def _ExtractImportantEnvironment(output_of_set):
   return env
 
 
-def _SetupScript(target_arch, sdk_dir):
+def _SetupScript(target_arch, sdk_dir, vc_bin_subdir):
   """Returns a command (with arguments) to be used to set up the
   environment."""
   # Check if we are running in the SDK command line environment and use
@@ -68,7 +68,7 @@ def _SetupScript(target_arch, sdk_dir):
     # TODO(scottmg|dpranke): Non-depot_tools toolchain: need to get Visual
     # Studio install location from registry.
     return [os.path.normpath(os.path.join(FIND_VS_IN_REG, 'VC/vcvarsall.bat')),
-            'amd64_x86' if target_arch == 'x86' else 'amd64']
+            vc_bin_subdir]
 
 
 def _FormatAsEnvironmentBlock(envvar_dict):
@@ -98,23 +98,28 @@ def _CopyTool(source_path):
 
 
 def main():
-  if len(sys.argv) != 5:
+  if len(sys.argv) != 6:
     print('Usage setup_toolchain.py '
-          '<visual studio path> <win tool path> <win sdk path> <runtime dirs>')
+          '<visual studio path> <win tool path> <win sdk path> '
+          '<runtime dirs> <cpu_arch>')
     sys.exit(2)
   vs_path = sys.argv[1]
   tool_source = sys.argv[2]
   win_sdk_path = sys.argv[3]
   runtime_dirs = sys.argv[4]
+  cpu_arch = sys.argv[5]
 
   _CopyTool(tool_source)
 
   archs = ('x86', 'x64')
+  assert cpu_arch in archs
+  vc_bin_subdir = 'amd64_x86' if cpu_arch == 'x86' else 'amd64'

[scottmg, 2014/11/21 22:26:59]

i guess that's ok :) at least it's all in this script now. the code that's
actually executing (DEPOT_TOOLS_WIN_TOOLCHAIN defaults to 1) isn't using this,
so it's still sort of in two places.

+
   # TODO(scottmg|goma): Do we need an equivalent of
   # ninja_use_custom_environment_files?
   for arch in archs:
     # Extract environment variables for subprocesses.
-    args = _SetupScript(arch, win_sdk_path)
+    args = _SetupScript(arch, win_sdk_path, vc_bin_subdir)
     args.extend(('&&', 'set'))
     popen = subprocess.Popen(
         args, shell=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
@@ -129,6 +134,8 @@ def main():
     with open('environment.' + arch, 'wb') as f:
       f.write(env_block)
 
+  print 'vc_bin_dir = "%s"' % os.path.join(vs_path, 'VC', 'bin', vc_bin_subdir)
+
 
 if __name__ == '__main__':
   main()