Silence excessive build logs when enable_incremental_javac = true

build/android/gyp/javac.py

 #!/usr/bin/env python
 #
 # Copyright 2013 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.
 
 import optparse
 import os
 import shutil
 import re
@@ skipping 132 matching lines @@
   skip_next = False
   for arg in javac_cmd[1:]:
     if not skip_next and arg not in do_not_prefix:
       arg = '-C' + arg
     new_args.append(arg)
     skip_next = arg in do_not_prefix
 
   return new_args
 
 
-def _FilterJMakeOutput(stdout):
-  if md5_check.PRINT_EXPLANATIONS:
-    return stdout
-  return re.sub(r'\b(Jmake version|Writing project database).*?\n', '', stdout)
-
-
 def _FixTempPathsInIncrementalMetadata(pdb_path, temp_dir):
   # The .pdb records absolute paths. Fix up paths within /tmp (srcjars).
   if os.path.exists(pdb_path):
     # Although its a binary file, search/replace still seems to work fine.
     with open(pdb_path) as fileobj:
       pdb_data = fileobj.read()
     with open(pdb_path, 'w') as fileobj:
       fileobj.write(re.sub(r'/tmp/[^/]*', temp_dir, pdb_data))
 
 
@@ skipping 61 matching lines @@
         # Add the extracted files to the classpath. This is required because
         # when compiling only a subset of files, classes that haven't changed
         # need to be findable.
         classpath_idx = javac_cmd.index('-classpath')
         javac_cmd[classpath_idx + 1] += ':' + classes_dir
 
       # Don't include the output directory in the initial set of args since it
       # being in a temp dir makes it unstable (breaks md5 stamping).
       cmd = javac_cmd + ['-d', classes_dir] + java_files
 
+      # JMake prints out some diagnostic logs that we want to ignore.
+      # This assumes that all compiler output goes through stderr.
+      stdout_filter = lambda s: ''
+      if md5_check.PRINT_EXPLANATIONS:
+        stdout_filter = None
+
       build_utils.CheckOutput(
           cmd,
           print_stdout=options.chromium_code,
-          stdout_filter=_FilterJMakeOutput,
+          stdout_filter=stdout_filter,
           stderr_filter=ColorJavacOutput)
 
     if options.main_class or options.manifest_entry:
       entries = []
       if options.manifest_entry:
         entries = [e.split(':') for e in options.manifest_entry]
       manifest_file = os.path.join(temp_dir, 'manifest')
       _CreateManifest(manifest_file, runtime_classpath, options.main_class,
                       entries)
     else:
@@ skipping 183 matching lines @@
       options,
       input_paths=input_paths,
       input_strings=javac_cmd,
       output_paths=output_paths,
       force=force,
       pass_changes=True)
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv[1:]))