Beginning work on GN build

build/toolchain/gcc_link_wrapper.py

+#!/usr/bin/env python
+# Copyright 2015 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.
+
+"""Runs a linking command and optionally a strip command.
+
+This script exists to avoid using complex shell commands in
+gcc_toolchain.gni's tool("link"), in case the host running the compiler
+does not have a POSIX-like shell (e.g. Windows).
+"""
+
+import argparse
+import subprocess
+import sys
+
+
+# When running on a Windows host and using a toolchain whose tools are
+# actually wrapper scripts (i.e. .bat files on Windows) rather than binary
+# executables, the "command" to run has to be prefixed with this magic.
+# The GN toolchain definitions take care of that for when GN/Ninja is
+# running the tool directly.  When that command is passed in to this
+# script, it appears as a unitary string but needs to be split up so that
+# just 'cmd' is the actual command given to Python's subprocess module.
+BAT_PREFIX = 'cmd /c call '
+
+def CommandToRun(command):
+  if command[0].startswith(BAT_PREFIX):
+    command = command[0].split(None, 3) + command[1:]
+  return command
+
+
+def main():
+  parser = argparse.ArgumentParser(description=__doc__)
+  parser.add_argument('--strip',
+                      help='The strip binary to run',
+                      metavar='PATH')
+  parser.add_argument('--unstripped-file',
+                      required=True,
+                      help='Executable file produced by linking command',
+                      metavar='FILE')
+  parser.add_argument('--output',
+                      required=True,
+                      help='Final output executable file',
+                      metavar='FILE')
+  parser.add_argument('command', nargs='+',
+                      help='Linking command')
+  args = parser.parse_args()
+
+  # First, run the actual link.
+  result = subprocess.call(CommandToRun(args.command))
+  if result != 0:
+    return result
+
+  # Finally, strip the linked executable (if desired).
+  if args.strip:
+    result = subprocess.call(CommandToRun([
+        args.strip, '--strip-unneeded', '-o', args.output, args.unstripped_file
+        ]))
+
+  return result
+
+
+if __name__ == "__main__":
+  sys.exit(main())