gn win: Various toolchain fixes to get compile working

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 5e292ab07840c546504194411343f73223390208..42c3af1b6cd7e65d3e0641d680ecc9162952cbe1 100644
--- a/build/toolchain/win/setup_toolchain.py
+++ b/build/toolchain/win/setup_toolchain.py
@@ -19,39 +19,59 @@ and the files will be written to the current directory.
 """
 
 
-def ExtractImportantEnvironment():
-  """Extracts environment variables required for the toolchain from the
-  current environment."""
+def _ExtractImportantEnvironment(output_of_set):
+  """Extracts environment variables required for the toolchain to run from
+  a textual dump output by the cmd.exe 'set' command."""
   envvars_to_save = (
-      'goma_.*',  # TODO(scottmg): This is ugly, but needed for goma.
-      'include',  # Needed by midl compiler.
+      'goma_.*', # TODO(scottmg): This is ugly, but needed for goma.
+      'include',
+      'lib',
+      'libpath',
       'path',
       'pathext',
       'systemroot',
       'temp',
       'tmp',
       )
-  result = {}
-  for envvar in envvars_to_save:
-    if envvar in os.environ:
-      envvar = envvar.lower()
-      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.
-        result[envvar.upper()] = os.path.dirname(sys.executable) + \
-            os.pathsep + os.environ[envvar]
-      else:
-        result[envvar.upper()] = os.environ[envvar]
+  env = {}
+  for line in output_of_set.splitlines():
+    for envvar in envvars_to_save:
+      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 result:
+    if required not in env:
       raise Exception('Environment variable "%s" '
                       'required to be set to valid path' % required)
-  return result
+  return env
 
 
-def FormatAsEnvironmentBlock(envvar_dict):
+def _SetupScript(target_arch, sdk_dir):
+  """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
+  # the setup script from the SDK if so. |target_arch| should be either
+  # 'x86' or 'x64'.
+  assert target_arch in ('x86', 'x64')
+  if bool(int(os.environ.get('DEPOT_TOOLS_WIN_TOOLCHAIN', 1))) and sdk_dir:
+    return [os.path.normpath(os.path.join(sdk_dir, 'Bin/SetEnv.Cmd')),
+            '/' + target_arch]
+  else:
+    # We only support x64-hosted tools.
+    # 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']
+
+
+def _FormatAsEnvironmentBlock(envvar_dict):
   """Format as an 'environment block' directly suitable for CreateProcess.
   Briefly this is a list of key=value\0, terminated by an additional \0. See
   CreateProcess documentation for more details."""
@@ -63,7 +83,7 @@ def FormatAsEnvironmentBlock(envvar_dict):
   return block
 
 
-def CopyTool(source_path):
+def _CopyTool(source_path):
   """Copies the given tool to the current directory, including a warning not
   to edit it."""
   with open(source_path) as source_file:
@@ -76,33 +96,39 @@ def CopyTool(source_path):
                              '# Generated by setup_toolchain.py do not edit.\n']
                             + tool_source[1:]))
 
-if len(sys.argv) != 4:
-  print('Usage setup_toolchain.py '
-        '<visual studio path> <win tool path> <win sdk path>')
-  sys.exit(2)
-vs_path = sys.argv[1]
-tool_source = sys.argv[2]
-win_sdk_path = sys.argv[3]
-
-CopyTool(tool_source)
-
-important_env_vars = ExtractImportantEnvironment()
-path = important_env_vars["PATH"].split(";")
-
-# Add 32-bit compiler path to the beginning and write the block.
-path32 = [os.path.join(vs_path, "VC\\BIN")] + \
-         [os.path.join(win_sdk_path, "bin\\x86")] + \
-         path
-important_env_vars["PATH"] = ";".join(path32)
-environ = FormatAsEnvironmentBlock(important_env_vars)
-with open('environment.x86', 'wb') as env_file:
-  env_file.write(environ)
-
-# Add 64-bit compiler path to the beginning and write the block.
-path64 = [os.path.join(vs_path, "VC\\BIN\\amd64")] + \
-         [os.path.join(win_sdk_path, "bin\\x64")] + \
-         path
-important_env_vars["PATH"] = ";".join(path64)
-environ = FormatAsEnvironmentBlock(important_env_vars)
-with open('environment.x64', 'wb') as env_file:
-  env_file.write(environ)
+
+def main():
+  if len(sys.argv) != 5:
+    print('Usage setup_toolchain.py '
+          '<visual studio path> <win tool path> <win sdk path> <runtime dirs>')
+    sys.exit(2)
+  vs_path = sys.argv[1]
+  tool_source = sys.argv[2]
+  win_sdk_path = sys.argv[3]
+  runtime_dirs = sys.argv[4]
+
+  _CopyTool(tool_source)
+
+  archs = ('x86', 'x64')
+  # 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.extend(('&&', 'set'))
+    popen = subprocess.Popen(
+        args, shell=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
+    variables, _ = popen.communicate()
+    env = _ExtractImportantEnvironment(variables)
+    env['PATH'] = runtime_dirs + ';' + env['PATH']
+
+    # TODO(scottmg|thakis|dpranke): Is there an equivalent to
+    # msvs_system_include_dirs that we need to inject into INCLUDE here?
+
+    env_block = _FormatAsEnvironmentBlock(env)
+    with open('environment.' + arch, 'wb') as f:
+      f.write(env_block)
+
+
+if __name__ == '__main__':
+  main()