Let build/vs_toolchain.py run on non-Windows if requested.

build/vs_toolchain.py

+#!/usr/bin/env python
 # Copyright 2014 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.
 
 import json
 import os
 import pipes
 import shutil
 import subprocess
 import sys
@@ skipping 11 matching lines @@
 
 
 def SetEnvironmentAndGetRuntimeDllDirs():
   """Sets up os.environ to use the depot_tools VS toolchain with gyp, and
   returns the location of the VS runtime DLLs so they can be copied into
   the output directory after gyp generation.
   """
   vs2013_runtime_dll_dirs = None
   depot_tools_win_toolchain = \
       bool(int(os.environ.get('DEPOT_TOOLS_WIN_TOOLCHAIN', '1')))
-  if sys.platform in ('win32', 'cygwin') and depot_tools_win_toolchain:
+  # When running on a non-Windows host, only do this if the SDK has explicitly
+  # been downloaded before (in which case json_data_file will exist).
+  if ((sys.platform in ('win32', 'cygwin') and depot_tools_win_toolchain) or
+      os.path.exists(json_data_file)):
     if not os.path.exists(json_data_file):
       Update()
     with open(json_data_file, 'r') as tempf:
       toolchain_data = json.load(tempf)
 
     toolchain = toolchain_data['path']
     version = toolchain_data['version']
     win_sdk = toolchain_data.get('win_sdk')
     if not win_sdk:
       win_sdk = toolchain_data['win8sdk']
@@ skipping 66 matching lines @@
 
 
 def CopyVsRuntimeDlls(output_dir, runtime_dirs):
   """Copies the VS runtime DLLs from the given |runtime_dirs| to the output
   directory so that even if not system-installed, built binaries are likely to
   be able to run.
 
   This needs to be run after gyp has been run so that the expected target
   output directories are already created.
   """
-  assert sys.platform.startswith(('win32', 'cygwin'))
-
   x86, x64 = runtime_dirs
   out_debug = os.path.join(output_dir, 'Debug')
   out_debug_nacl64 = os.path.join(output_dir, 'Debug', 'x64')
   out_release = os.path.join(output_dir, 'Release')
   out_release_nacl64 = os.path.join(output_dir, 'Release', 'x64')
   out_debug_x64 = os.path.join(output_dir, 'Debug_x64')
   out_release_x64 = os.path.join(output_dir, 'Release_x64')
 
   if os.path.exists(out_debug) and not os.path.exists(out_debug_nacl64):
     os.makedirs(out_debug_nacl64)
@@ skipping 55 matching lines @@
 def _GetDesiredVsToolchainHashes():
   """Load a list of SHA1s corresponding to the toolchains that we want installed
   to build with."""
   if os.environ.get('GYP_MSVS_VERSION') == '2015':
     return ['49ae4b60d898182fc3f521c2fcda82c453915011']
   else:
     # Default to VS2013.
     return ['ee7d718ec60c2dc5d255bbe325909c2021a7efef']
 
 
-def Update():
+def Update(force=False):
   """Requests an update of the toolchain to the specific hashes we have at
   this revision. The update outputs a .json of the various configuration
   information required to pass to gyp which we use in |GetToolchainDir()|.
   """
+  if force != False and force != '--force':
+    print >>sys.stderr, 'Unknown parameter "%s"' % force
+    return 1
+  if force == '--force' or os.path.exists(json_data_file):
+    force = True
+
   depot_tools_win_toolchain = \
       bool(int(os.environ.get('DEPOT_TOOLS_WIN_TOOLCHAIN', '1')))
-  if sys.platform in ('win32', 'cygwin') and depot_tools_win_toolchain:
+  if ((sys.platform in ('win32', 'cygwin') or force) and
+        depot_tools_win_toolchain):
     import find_depot_tools
     depot_tools_path = find_depot_tools.add_depot_tools_to_path()
     get_toolchain_args = [
         sys.executable,
         os.path.join(depot_tools_path,
                     'win_toolchain',
                     'get_toolchain_if_necessary.py'),
         '--output-json', json_data_file,
       ] + _GetDesiredVsToolchainHashes()
+    if force:
+      get_toolchain_args.append('--force')
     subprocess.check_call(get_toolchain_args)
 
   return 0
 
 
 def GetToolchainDir():
   """Gets location information about the current toolchain (must have been
   previously updated by 'update'). This is used for the GN build."""
   runtime_dll_dirs = SetEnvironmentAndGetRuntimeDllDirs()
 
@@ skipping 10 matching lines @@
 runtime_dirs = "%s"
 ''' % (
       os.environ['GYP_MSVS_OVERRIDE_PATH'],
       os.environ['WINDOWSSDKDIR'],
       os.environ['GYP_MSVS_VERSION'],
       os.environ.get('WDK_DIR', ''),
       ';'.join(runtime_dll_dirs or ['None']))
 
 
 def main():
-  if not sys.platform.startswith(('win32', 'cygwin')):
-    return 0
   commands = {
       'update': Update,
       'get_toolchain_dir': GetToolchainDir,
       'copy_dlls': CopyDlls,
   }
   if len(sys.argv) < 2 or sys.argv[1] not in commands:
     print >>sys.stderr, 'Expected one of: %s' % ', '.join(commands)
     return 1
   return commands[sys.argv[1]](*sys.argv[2:])
 
 
 if __name__ == '__main__':
   sys.exit(main())