Output a linker map file for official builds

build/toolchain/gcc_link_wrapper.py

Index: build/toolchain/gcc_link_wrapper.py
diff --git a/build/toolchain/gcc_link_wrapper.py b/build/toolchain/gcc_link_wrapper.py
index c589fe330d4c10926aa1411af00a1942ee56f7f4..0e256fab2fb672e54a638a660ab8399a5aac426f 100755
--- a/build/toolchain/gcc_link_wrapper.py
+++ b/build/toolchain/gcc_link_wrapper.py
@@ -15,6 +15,8 @@ import os
 import subprocess
 import sys
 
+import wrapper_utils
+
 
 # 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
@@ -37,9 +39,12 @@ def main():
                       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('--map-file',
+                      help=('Use --Wl,-Map to generate a map file. Will be '
+                            'gzipped if extension ends with .gz'),
+                      metavar='FILE')
   parser.add_argument('--output',
                       required=True,
                       help='Final output executable file',
@@ -51,7 +56,8 @@ def main():
   # Work-around for gold being slow-by-default. http://crbug.com/632230
   fast_env = dict(os.environ)
   fast_env['LC_ALL'] = 'C'
-  result = subprocess.call(CommandToRun(args.command), env=fast_env)
+  result = wrapper_utils.RunLinkWithOptionalMapFile(args.command, env=fast_env,
+                                                    map_file=args.map_file)
   if result != 0:
     return result