Honor $CC/$CC_host and friends in make generator.

pylib/gyp/msvs_emulation.py

Index: pylib/gyp/msvs_emulation.py
diff --git a/pylib/gyp/msvs_emulation.py b/pylib/gyp/msvs_emulation.py
index 4a55aca05751de49c017caf98c6ed870d0f8556a..9a668c8d3b586ead3625fc856294e4c5e70abe7b 100644
--- a/pylib/gyp/msvs_emulation.py
+++ b/pylib/gyp/msvs_emulation.py
@@ -113,6 +113,9 @@ def _FindDirectXInstallation():
   """Try to find an installation location for the DirectX SDK. Check for the
   standard environment variable, and if that doesn't exist, try to find
   via the registry. May return None if not found in either location."""
+  if sys.platform not in ('win32', 'cygwin'):
+    return ''

[Nico, 2012/08/14 21:36:26]

Why do you need this?

[Sam Clegg, 2012/08/14 22:36:57]

It allows me to do --format=ninja-win on my linux box to 
generate the ninja file for windows (more of less).

[Nico, 2012/08/14 22:42:26]

That sounds unrelated to what this CL is about then. Can you do it in another
CL? (This might not be the right place to do it.)

+
   # Return previously calculated value, if there is one
   if hasattr(_FindDirectXInstallation, 'dxsdk_dir'):
     return _FindDirectXInstallation.dxsdk_dir
@@ -678,6 +681,8 @@ def GenerateEnvironmentFiles(toplevel_build_dir, generator_flags, open_out):
   an absolute path, instead preferring something like "cl.exe" in the rule
   which will then run whichever the environment setup has put in the path."""
   vs = GetVSVersion(generator_flags)
+  if sys.platform not in ('win32', 'cygwin'):
+    return
   for arch in ('x86', 'x64'):
     args = vs.SetupScript(arch)
     args.extend(('&&', 'set'))