win: Decide how to include system dirs at toolchain time instead of globally.

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 134 matching lines @@
   CreateProcess documentation for more details."""
   block = ''
   nul = '\0'
   for key, value in envvar_dict.iteritems():
     block += key + '=' + value + nul
   block += nul
   return block
 
 
 def main():
-  if len(sys.argv) != 6:
+  if len(sys.argv) != 5:
     print('Usage setup_toolchain.py '
           '<visual studio path> <win sdk path> '
           '<runtime dirs> <target_cpu> <include prefix>')
     sys.exit(2)
   win_sdk_path = sys.argv[2]
   runtime_dirs = sys.argv[3]
   target_cpu = sys.argv[4]
-  include_prefix = sys.argv[5]
 
   cpus = ('x86', 'x64')
   assert target_cpu in cpus
   vc_bin_dir = ''
   include = ''
 
   # 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.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
       # The separator for INCLUDE here must match the one used in
       # _LoadToolchainEnv() above.
-      include = [include_prefix + p for p in env['INCLUDE'].split(';') if p]
-      include = ' '.join(['"' + i.replace('"', r'\"') + '"' for i in include])
+      include = [p.replace('"', r'\"') for p in env['INCLUDE'].split(';') if p]
+      include_I = ' '.join(['"/I' + i + '"' for i in include])
+      include_imsvc = ' '.join(['"-imsvc' + i + '"' for i in 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 = ' + gn_helpers.ToGNString(vc_bin_dir)
-  assert include
-  print 'include_flags = ' + gn_helpers.ToGNString(include)
+  assert include_I
+  print 'include_flags_I = ' + gn_helpers.ToGNString(include_I)

[Nico, 2017/03/03 22:17:48]

this is currently not read anywhere, but if the MS branch where to use this flag
instead of the env subprocess, this is how we'd do it. seemed a bit nicer to
output this too, but I can drop include_I if you think YAGNI is better. (I
usually do think that.)

+  assert include_imsvc
+  print 'include_flags_imsvc = ' + gn_helpers.ToGNString(include_imsvc)
 
 if __name__ == '__main__':
   main()