Beginning work on GN build

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
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+# 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
+# and the files will be written to the current directory.
+
+import errno
+import json
+import os
+import re
+import subprocess
+import sys
+
+SCRIPT_DIR = os.path.dirname(__file__)
+
+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',
+      'lib',
+      'libpath',
+      'path',
+      'pathext',
+      'systemroot',
+      'temp',
+      'tmp',
+      )
+  env = {}
+  # This occasionally happens and leads to misleading SYSTEMROOT error messages
+  # if not caught here.
+  if output_of_set.count('=') == 0:
+    raise Exception('Invalid output_of_set. Value is:\n%s' % output_of_set)
+  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
+  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'))
+  import vs_toolchain
+  return vs_toolchain.DetectVisualStudioPath()
+
+
+def _LoadEnvFromBat(args):
+  """Given a bat command, runs it and returns env vars set by it."""
+  args = args[:]
+  args.extend(('&&', 'set'))
+  popen = subprocess.Popen(
+      args, shell=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
+  variables, _ = popen.communicate()
+  if popen.returncode != 0:
+    raise Exception('"%s" failed with error %d' % (args, popen.returncode))
+  return variables
+
+
+def _LoadToolchainEnv(cpu, sdk_dir):
+  """Returns a dictionary with environment variables that must be set while
+  running binaries from the toolchain (e.g. INCLUDE and PATH for cl.exe)."""
+  # Check if we are running in the SDK command line environment and use
+  # the setup script from the SDK if so. |cpu| should be either
+  # 'x86' or 'x64'.
+  assert cpu in ('x86', 'x64')
+  if bool(int(os.environ.get('DEPOT_TOOLS_WIN_TOOLCHAIN', 1))) and sdk_dir:
+    # Load environment from json file.
+    env = os.path.normpath(os.path.join(sdk_dir, 'Bin/SetEnv.%s.json' % cpu))
+    env = json.load(open(env))['env']
+    for k in env:
+      entries = [os.path.join(*([os.path.join(sdk_dir, 'bin')] + e))
+                 for e in env[k]]
+      # clang-cl wants INCLUDE to be ;-separated even on non-Windows,
+      # lld-link wants LIB to be ;-separated even on non-Windows.  Path gets :.
+      # The separator for INCLUDE here must match the one used in main() below.
+      sep = os.pathsep if k == 'PATH' else ';'
+      env[k] = sep.join(entries)
+    # PATH is a bit of a special case, it's in addition to the current PATH.
+    env['PATH'] = env['PATH'] + os.pathsep + os.environ['PATH']
+    # Augment with the current env to pick up TEMP and friends.
+    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.
+    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.
+    script_path = os.path.normpath(os.path.join(
+                                       os.environ['GYP_MSVS_OVERRIDE_PATH'],
+                                       'VC/vcvarsall.bat'))
+    if not os.path.exists(script_path):
+      raise Exception('%s is missing - make sure VC++ tools are installed.' %
+                      script_path)
+    args = [script_path, 'amd64_x86' if cpu == 'x86' else 'amd64']
+    variables = _LoadEnvFromBat(args)
+  return _ExtractImportantEnvironment(variables)
+
+
+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."""
+  block = ''
+  nul = '\0'
+  for key, value in envvar_dict.iteritems():
+    block += key + '=' + value + nul
+  block += nul
+  return block
+
+
+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:
+    tool_source = source_file.readlines()
+
+  # Add header and write it out to the current directory (which should be the
+  # root build dir). Don't write the file if a matching file already exists
+  # because that causes a cascade of unnecessary rebuilds.
+  match = False
+  contents = ''.join([tool_source[0],
+                      '# Generated by setup_toolchain.py do not edit.\n']
+                     + tool_source[1:])
+  out_path = 'gyp-win-tool'
+  try:
+    with open(out_path, 'rb') as read_tool_file:
+      existing_contents = read_tool_file.read()
+    if existing_contents == contents:
+      match = True
+  except:
+    pass
+  if not match:
+    with open(out_path, 'wb') as write_tool_file:
+      write_tool_file.write(contents)
+
+
+def main():
+  if len(sys.argv) != 7:
+    print('Usage setup_toolchain.py '
+          '<visual studio path> <win tool path> <win sdk path> '
+          '<runtime dirs> <target_cpu> <include prefix>')
+    sys.exit(2)
+  tool_source = sys.argv[2]
+  win_sdk_path = sys.argv[3]
+  runtime_dirs = sys.argv[4]
+  target_cpu = sys.argv[5]
+  include_prefix = sys.argv[6]
+
+  _CopyTool(tool_source)
+
+  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 = ' '.join([include_prefix + p
+                          for p in env['INCLUDE'].split(';')])
+
+    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
+  assert '"' not in vc_bin_dir
+  print 'vc_bin_dir = "%s"' % vc_bin_dir
+  assert include
+  assert '"' not in include
+  print 'include_flags = "%s"' % include
+
+if __name__ == '__main__':
+  main()