Make javac invocations incremental when possible

build/android/gyp/util/build_utils.py

 # 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 ast
 import contextlib
 import fnmatch
 import json
 import os
 import pipes
@@ skipping 178 matching lines @@
   return device_state.strip() == 'device'
 
 
 def CheckZipPath(name):
   if os.path.normpath(name) != name:
     raise Exception('Non-canonical zip path: %s' % name)
   if os.path.isabs(name):
     raise Exception('Absolute zip path: %s' % name)
 
 
-def ExtractAll(zip_path, path=None, no_clobber=True, pattern=None):
+def ExtractAll(zip_path, path=None, no_clobber=True, pattern=None,
+               predicate=None):
   if path is None:
     path = os.getcwd()
   elif not os.path.exists(path):
     MakeDirectory(path)
 
   with zipfile.ZipFile(zip_path) as z:
     for name in z.namelist():
       if name.endswith('/'):
         continue
       if pattern is not None:
         if not fnmatch.fnmatch(name, pattern):
           continue
+      if predicate is not None and not predicate(name):

[jbudorick, 2015/09/23 00:26:20]

I don't think functions can be interpreted as false, so I think this would be
fine as

  if predicate and not predicate(name):

[agrieve, 2015/09/23 02:07:56]

Done.

+        continue
       CheckZipPath(name)
       if no_clobber:
         output_path = os.path.join(path, name)
         if os.path.exists(output_path):
           raise Exception(
               'Path already exists from zip: %s %s %s'
               % (zip_path, name, output_path))
 
     z.extractall(path=path)
 
@@ skipping 174 matching lines @@
     expansion = file_jsons[file_path]
     for k in lookup_path[1:]:
       expansion = expansion[k]
 
     new_args[i] = arg[:match.start()] + str(expansion)
 
   return new_args
 
 
 def CallAndRecordIfStale(function, options, record_path=None, input_paths=None,
-                         input_strings=None, output_paths=None, force=False):
+                         input_strings=None, output_paths=None, force=False,
+                         pass_changes=False):
   """Wraps md5_check.CallAndRecordIfStale() and also writes dep & stamp files.
 
   Depfiles and stamp files are automatically added to output_paths when present
   in the |options| arguemnt. They are then created after |function| is called.
   """
   if not output_paths:
     raise Exception('At least one output_path must be specified.')
   input_paths = list(input_paths or [])
   input_strings = list(input_strings or [])
   output_paths = list(output_paths or [])
 
   python_deps = None
   if hasattr(options, 'depfile') and options.depfile:
     python_deps = GetPythonDependencies()
     # List python deps in input_strings rather than input_paths since the
     # contents of them does not change what gets written to the depfile.
     input_strings += python_deps
     output_paths += [options.depfile]
 
   stamp_file = hasattr(options, 'stamp') and options.stamp
   if stamp_file:
     output_paths += [stamp_file]
 
-  def on_stale_md5():
-    function()
+  def on_stale_md5(changes):
+    args = (changes,) if pass_changes else ()
+    function(*args)
     if python_deps is not None:
       WriteDepfile(options.depfile, python_deps + input_paths)
     if stamp_file:
       Touch(stamp_file)
 
   md5_check.CallAndRecordIfStale(
       on_stale_md5,
       record_path=record_path,
       input_paths=input_paths,
       input_strings=input_strings,
       output_paths=output_paths,
-      force=force)
+      force=force,
+      pass_changes=True)