Allow proto-path in the proto_library target

tools/protoc_wrapper/protoc_wrapper.py

 #!/usr/bin/env python
 # Copyright (c) 2012 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.
 
 """
 A simple wrapper for protoc.
 Script for //third_party/protobuf/proto_library.gni .
 Features:
 - Inserts #include for extra header automatically.
@@ skipping 56 matching lines @@
         print(line, file=f)
 
 
 def main(argv):
   parser = argparse.ArgumentParser()
   parser.add_argument("--protoc",
                       help="Relative path to compiler.")
 
   parser.add_argument("--proto-in-dir",
                       help="Base directory with source protos.")
+  parser.add_argument("--proto-path",

[sdefresne, 2016/10/04 11:29:55]

I would make this an argument that can be passed multiple time (ie.
action="append").

parser.add_argument("--proto-path", action="append",
                       help="Base directory with imported protos.")

[Olivier, 2016/10/04 12:44:31]

Done.

+                      help="Base directory with imported protos.")
   parser.add_argument("--cc-out-dir",
                       help="Output directory for standard C++ generator.")
   parser.add_argument("--py-out-dir",
                       help="Output directory for standard Python generator.")
   parser.add_argument("--plugin-out-dir",
                       help="Output directory for custom generator plugin.")
 
   parser.add_argument("--plugin",
                       help="Relative path to custom generator plugin.")
   parser.add_argument("--plugin-options",
@@ skipping 27 matching lines @@
       headers.append(os.path.join(cc_out_dir, stripped_name + ".pb.h"))
 
   if options.plugin_out_dir:
     plugin_options = FormatGeneratorOptions(options.plugin_options)
     protoc_cmd += [
       "--plugin", "protoc-gen-plugin=" + os.path.relpath(options.plugin),
       "--plugin_out", plugin_options + options.plugin_out_dir
     ]
 
   protoc_cmd += ["--proto_path", proto_dir]
+  if options.proto_path:

[sdefresne, 2016/10/04 11:29:55]

If you change the argument to one that accept multiple items, then you need to
change this to a loop (note that the if before the for is there because the
value will be None if the option is not used, it is possible to remove the need
for the if by adding default=[] to the add_argument call):

if options.proto_path:
  for extra_proto_dir in options.proto_path:
    proto_cmd.extend(["--proto_path", os.path.relpath(extra_proto_dir)]

[Olivier, 2016/10/04 12:44:31]

Done.
Kept the + [] instead of extend for file consistency.

+    protoc_cmd += ["--proto_path", os.path.relpath(options.proto_path)]
+
   protoc_cmd += [os.path.join(proto_dir, name) for name in protos]
   ret = subprocess.call(protoc_cmd)
   if ret != 0:
     raise RuntimeError("Protoc has returned non-zero status: "
                        "{0} .".format(ret))
 
   if options.include:
     WriteIncludes(headers, options.include)
 
 
 if __name__ == "__main__":
   try:
     main(sys.argv)
   except RuntimeError as e:
     print(e, file=sys.stderr)
     sys.exit(1)