Closure compilation: Modify compile_js2.py to not swallow errors.

third_party/closure_compiler/compile2.py

 #!/usr/bin/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 Closure compiler on JavaScript files to check for errors and produce
 minified output."""
 
 import argparse
 import os
@@ skipping 225 matching lines @@
       os.makedirs(out_dir)
 
     checks_only = 'checks_only' in closure_args
 
     if not checks_only:
       args += ["--js_output_file=%s" % out_file]
       args += ["--create_source_map=%s" % (self._MAP_FILE_FORMAT % out_file)]
 
     self._log_debug("Args: %s" % " ".join(args))
 
-    _, stderr = self.run_jar(self._compiler_jar, args)
+    return_code, stderr = self.run_jar(self._compiler_jar, args)
 
     errors = stderr.strip().split("\n\n")
     maybe_summary = errors.pop()
 
     summary = re.search("(?P<error_count>\d+).*error.*warning", maybe_summary)
     if summary:
       self._log_debug("Summary: %s" % maybe_summary)
     else:
       # Not a summary. Running the jar failed. Bail.
       self._log_error(stderr)
       self._nuke_temp_files()
       sys.exit(1)
 
     if summary.group('error_count') != "0":
       if os.path.exists(out_file):
         os.remove(out_file)
       if os.path.exists(self._MAP_FILE_FORMAT % out_file):
         os.remove(self._MAP_FILE_FORMAT % out_file)
-    elif checks_only:
+    elif checks_only and return_code == 0:
       # Compile succeeded but --checks_only disables --js_output_file from
       # actually writing a file. Write a file ourselves so incremental builds
       # still work.
       with open(out_file, 'w') as f:
         f.write('')
 
     if process_includes:
       errors = map(self._clean_up_error, errors)
       output = self._format_errors(errors)
 
       if errors:
         prefix = "\n" if output else ""
         self._log_error("Error in: %s%s%s" % (self._target, prefix, output))
       elif output:
         self._log_debug("Output: %s" % output)
 
     self._nuke_temp_files()
-    return bool(errors), stderr
+    return bool(errors) or return_code > 0, stderr
 
 
 if __name__ == "__main__":
   parser = argparse.ArgumentParser(
       description="Typecheck JavaScript using Closure compiler")
   parser.add_argument("sources", nargs=argparse.ONE_OR_MORE,
                       help="Path to a source file to typecheck")
   parser.add_argument("--custom_sources", action="store_true",
                       help="Whether this rules has custom sources.")
   parser.add_argument("--custom_includes", action="store_true",
@@ skipping 11 matching lines @@
 
   found_errors, stderr = checker.check(opts.sources, out_file=opts.out_file,
                                        closure_args=opts.closure_args,
                                        custom_sources=opts.custom_sources,
                                        custom_includes=opts.custom_includes)
 
   if found_errors:
     if opts.custom_sources:
       print stderr
     sys.exit(1)