Make setup_toolchain.py run on non-Windows.

build/toolchain/win/setup_toolchain.py

 # Copyright (c) 2013 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.
 #
 # Copies the given "win tool" (which the toolchain uses to wrap compiler
 # invocations) and the environment blocks for the 32-bit and 64-bit builds on
 # Windows to the build directory.
 #
 # The arguments are the visual studio install location and the location of the
 # win tool. The script assumes that the root build directory is the current dir
@@ skipping 32 matching lines @@
       if re.match(envvar + '=', line.lower()):
         var, setting = line.split('=', 1)
         if envvar == 'path':
           # Our own rules (for running gyp-win-tool) and other actions in
           # Chromium rely on python being in the path. Add the path to this
           # python here so that if it's not in the path when ninja is run
           # later, python will still be found.
           setting = os.path.dirname(sys.executable) + os.pathsep + setting
         env[var.upper()] = setting
         break
-  for required in ('SYSTEMROOT', 'TEMP', 'TMP'):
-    if required not in env:
-      raise Exception('Environment variable "%s" '
-                      'required to be set to valid path' % required)
+  if sys.platform in ('win32', 'cygwin'):
+    for required in ('SYSTEMROOT', 'TEMP', 'TMP'):
+      if required not in env:
+        raise Exception('Environment variable "%s" '
+                        'required to be set to valid path' % required)
   return env
 
 
 def _DetectVisualStudioPath():
   """Return path to the GYP_MSVS_VERSION of Visual Studio.
   """
 
   # Use the code in build/vs_toolchain.py to avoid duplicating code.
   chromium_dir = os.path.abspath(os.path.join(SCRIPT_DIR, '..', '..', '..'))
   sys.path.append(os.path.join(chromium_dir, 'build'))
@@ skipping 34 matching lines @@
     for k in os.environ:
       if k not in env:
         env[k] = os.environ[k]
 
     varlines = []
     for k in sorted(env.keys()):
       varlines.append('%s=%s' % (str(k), str(env[k])))
     variables = '\n'.join(varlines)
 
     # Check that the json file contained the same environment as the .cmd file.
-    script = os.path.normpath(os.path.join(sdk_dir, 'Bin/SetEnv.cmd'))
-    assert _ExtractImportantEnvironment(variables) == \
-           _ExtractImportantEnvironment(_LoadEnvFromBat([script, '/' + cpu]))
+    if sys.platform in ('win32', 'cygwin'):
+      script = os.path.normpath(os.path.join(sdk_dir, 'Bin/SetEnv.cmd'))
+      assert _ExtractImportantEnvironment(variables) == \
+             _ExtractImportantEnvironment(_LoadEnvFromBat([script, '/' + cpu]))
   else:
     if 'GYP_MSVS_OVERRIDE_PATH' not in os.environ:
       os.environ['GYP_MSVS_OVERRIDE_PATH'] = _DetectVisualStudioPath()
     # We only support x64-hosted tools.
     args = [os.path.normpath(os.path.join(os.environ['GYP_MSVS_OVERRIDE_PATH'],
                                           'VC/vcvarsall.bat')),
             'amd64_x86' if cpu == 'x86' else 'amd64']
     variables = _LoadEnvFromBat(args)
   return _ExtractImportantEnvironment(variables)
 
@@ skipping 40 matching lines @@
   cpus = ('x86', 'x64')
   assert target_cpu in cpus
   vc_bin_dir = ''
 
   # TODO(scottmg|goma): Do we need an equivalent of
   # ninja_use_custom_environment_files?
 
   for cpu in cpus:
     # Extract environment variables for subprocesses.
     env = _LoadToolchainEnv(cpu, win_sdk_path)
-    env['PATH'] = runtime_dirs + os.path.pathsep + env['PATH']
+    env['PATH'] = runtime_dirs + os.pathsep + env['PATH']
 
     if cpu == target_cpu:
       for path in env['PATH'].split(os.pathsep):
         if os.path.exists(os.path.join(path, 'cl.exe')):
           vc_bin_dir = os.path.realpath(path)
           break
 
     # Add extra include directories here that need to be in front of the
     # installed and packaged include directories. This may be needed in
     # order to force a particular SDK version, such as to get VS 2013 to use
     # the Windows 10 SDK. Beware of making the INCLUDE variable excessively
     # long and be sure to make corresponding changes to build\common.gypi.
     # Not currently used.
     #if win_sdk_path:

[scottmg, 2016/03/21 17:30:14]

I'm not sure why this is here, probably just nuke it.

[Nico, 2016/03/21 17:33:54]

I asked here:
https://codereview.chromium.org/1783773004/diff/1/build/toolchain/win/setup_t...

But deleting it in this CL sounds good to me, done.

+    #  # INCLUDE always uses ; separators, even on non-Windows.
     #  additional_includes = [
     #    os.path.join(win_sdk_path, 'Include', '10.0.10586.0', p)
     #    for p in ['shared', 'um', 'winrt']]
-    #  additional_includes = os.path.pathsep.join(additional_includes)
-    #  env['INCLUDE'] = additional_includes + os.path.pathsep + env['INCLUDE']
+    #  additional_includes = ';'.join(additional_includes)
+    #  env['INCLUDE'] = additional_includes + ';' + env['INCLUDE']
     env_block = _FormatAsEnvironmentBlock(env)
     with open('environment.' + cpu, 'wb') as f:
       f.write(env_block)
 
     # Create a store app version of the environment.
     if 'LIB' in env:
       env['LIB']     = env['LIB']    .replace(r'\VC\LIB', r'\VC\LIB\STORE')
     if 'LIBPATH' in env:
       env['LIBPATH'] = env['LIBPATH'].replace(r'\VC\LIB', r'\VC\LIB\STORE')
     env_block = _FormatAsEnvironmentBlock(env)
     with open('environment.winrt_' + cpu, 'wb') as f:
         f.write(env_block)
 
   assert vc_bin_dir
   print 'vc_bin_dir = "%s"' % vc_bin_dir
 
 
 if __name__ == '__main__':
   main()