Fix javac sometimes not create all outputs with enable_incremental_javac

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 210 matching lines @@
         if os.path.exists(options.jar_path):
           _ExtractClassFiles(options.jar_path, classes_dir, changed_java_files)
         if os.path.exists(excluded_jar_path):
           _ExtractClassFiles(excluded_jar_path, classes_dir, changed_java_files)
         # 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
 
+      # Can happen when a target goes from having no sources, to having sources.
+      # It's created by the call to build_utils.Touch() below.
+      if options.incremental:
+        if os.path.exists(pdb_path) and not os.path.getsize(pdb_path):
+          os.unlink(pdb_path)
+
       # 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
 
       attempt_build = lambda: build_utils.CheckOutput(
           cmd,
           print_stdout=options.chromium_code,
           stdout_filter=stdout_filter,
           stderr_filter=ColorJavacOutput)
       try:
         attempt_build()
       except build_utils.CalledProcessError as e:
         # Work-around for a bug in jmake (http://crbug.com/551449).
         if 'project database corrupted' not in e.output:
           raise
         print ('Applying work-around for jmake project database corrupted '
                '(http://crbug.com/551449).')
         os.unlink(pdb_path)
         attempt_build()
+    elif options.incremental:
+      # Make sure output exists.
+      build_utils.Touch(pdb_path)
 
     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:
       manifest_file = None
@@ skipping 182 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:]))