[Not for commit] Experiment for windows build flag comparison.

tools/gyp_flag_compare.py

 #!/usr/bin/env python
 
 # Copyright 2016 the V8 project authors. All rights reserved.
 # Copyright 2014 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.
 
 """Given the output of -t commands from a ninja build for a gyp and GN generated
 build, report on differences between the command lines."""
 
@@ skipping 80 matching lines @@
     if len(cc_file) != 1:
       print 'Skipping %s' % command_line
       continue
     assert len(cc_file) == 1
 
     if is_win:
       rsp_file = [x for x in command_line if x.endswith('.rsp')]
       assert len(rsp_file) <= 1
       if rsp_file:
         rsp_file = os.path.join(build_dir, rsp_file[0][1:])
+        if not os.path.exists(rsp_file):
+          print 'Warning: Skipping %s' % rsp_file
+          continue
         with open(rsp_file, "r") as open_rsp_file:
           command_line = shlex.split(open_rsp_file, posix=False)
 
     defines = [x for x in command_line if x.startswith('-D')]
     include_dirs = [x for x in command_line if x.startswith('-I')]
     dash_f = [x for x in command_line if x.startswith('-f')]
     warnings = \
         [x for x in command_line if x.startswith('/wd' if is_win else '-W')]
     others = [x for x in command_line if x not in defines and \
                                          x not in include_dirs and \
@@ skipping 67 matching lines @@
       output += '    In gyp, but not in GN:\n      %s' % '\n      '.join(
           sorted(missing_in_gyp)) + '\n'
       g_total_differences += len(missing_in_gyp)
     if missing_in_gn:
       output += '    In GN, but not in gyp:\n      %s' % '\n      '.join(
           sorted(missing_in_gn)) + '\n\n'
       g_total_differences += len(missing_in_gn)
   return output
 
 
-def Run(command_line):
+def Run(command_line, **kwargs):
   """Run |command_line| as a subprocess and return stdout. Raises on error."""
   try:
-    return subprocess.check_output(command_line, shell=True)
+    return subprocess.check_output(command_line, shell=True,**kwargs)
   except subprocess.CalledProcessError as e:
     # Rescue the output we got until the exception happened.
     print '#### Stdout: ####################################################'
     print e.output
     print '#################################################################'
     raise
 
 
+def compile(build_type, src_dir):
+  args = "python -u E:/b/build/scripts/tools/runit.py --show-path python E:/b/build/scripts/slave/compile.py --build-args=-d --build-args=keeprsp --gsutil-py-path E:/b/build/scripts/slave/.recipe_deps/depot_tools/gsutil.py --ninja-path E:/b/build/scripts/slave/.recipe_deps/depot_tools/ninja.exe --target %s --src-dir %s --goma-cache-dir E:/b/build/slave/goma_cache --compiler goma --goma-service-account-json-file C:/creds/service_accounts/service-account-goma-client.json --goma-dir E:/b/build/slave/cache/cipd/goma --goma-fail-fast --goma-disable-local-fallback -- all".replace('/', '\\')
+  return Run(args % (build_type, src_dir))
+
 def main():
   if len(sys.argv) < 4:
     print ('usage: %s gn_outdir gyp_outdir gn_target '
            '[gyp_target1, gyp_target2, ...]' % __file__)
     return 1
 
   if len(sys.argv) == 4:
     sys.argv.append(sys.argv[3])
   gn_out_dir = sys.argv[1]
+  gyp_out_dir = sys.argv[2]
+
+  build_type = os.path.basename(gyp_out_dir)
+  src_dir = os.path.dirname(os.path.dirname(gyp_out_dir))
+  print >> sys.stderr, 'Expecting gyp outdir in %s...' % gyp_out_dir
+  if sys.platform == 'win32':
+    # On Windows flags are stored in .rsp files which are created during build.
+    print >> sys.stderr, 'Building in %s...' % gyp_out_dir
+    # Run('ninja -C %s -d keeprsp %s' % (gyp_out_dir, " ".join(sys.argv[4:])))
+    compile(build_type, src_dir)
+
+  gyp = Run('ninja -C %s -t commands %s' % (gyp_out_dir, " ".join(sys.argv[4:])))
+
+  build_type = 'gn'
   print >> sys.stderr, 'Expecting gn outdir in %s...' % gn_out_dir
-  gn = Run('ninja -C %s -t commands %s' % (gn_out_dir, sys.argv[3]))
   if sys.platform == 'win32':
     # On Windows flags are stored in .rsp files which are created during build.
     print >> sys.stderr, 'Building in %s...' % gn_out_dir
-    Run('ninja -C %s -d keeprsp %s' % (gn_out_dir, sys.argv[3]))
-
-  gyp_out_dir = sys.argv[2]
-  print >> sys.stderr, 'Expecting gyp outdir in %s...' % gyp_out_dir
-  gyp = Run('ninja -C %s -t commands %s' % (gyp_out_dir, " ".join(sys.argv[4:])))
-  if sys.platform == 'win32':
-    # On Windows flags are stored in .rsp files which are created during build.
-    print >> sys.stderr, 'Building in %s...' % gyp_out_dir
-    Run('ninja -C %s -d keeprsp %s' % (gyp_out_dir, " ".join(sys.argv[4:])))
+    # Run('ninja -C %s -d keeprsp %s' % (gn_out_dir, sys.argv[3]))
+    compile(build_type, src_dir)
+  gn = Run('ninja -C %s -t commands %s' % (gn_out_dir, sys.argv[3]))
 
   all_gyp_flags = GetFlags(gyp.splitlines(),
                            os.path.join(os.getcwd(), gyp_out_dir))
   all_gn_flags = GetFlags(gn.splitlines(),
                           os.path.join(os.getcwd(), gn_out_dir))
   gyp_files = set(all_gyp_flags.keys())
   gn_files = set(all_gn_flags.keys())
   different_source_list = gyp_files != gn_files
   if different_source_list:
     print 'Different set of sources files:'
@@ skipping 38 matching lines @@
     print '\n'.join(sorted(files))
     print diff
 
   print 'Total differences:', g_total_differences
   # TODO(scottmg): Return failure on difference once we're closer to identical.
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(main())