CallAndRecordIfStale(): Add knownledge of output_files, depfiles, stamp

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
 import re
 import shlex
 import shutil
 import subprocess
 import sys
 import tempfile
 import zipfile
 
+from util import md5_check
 
 CHROMIUM_SRC = os.path.normpath(
     os.path.join(os.path.dirname(__file__),
                  os.pardir, os.pardir, os.pardir, os.pardir))
 COLORAMA_ROOT = os.path.join(CHROMIUM_SRC,
                              'third_party', 'colorama', 'src')
 # aapt should ignore OWNERS files in addition the default ignore pattern.
 AAPT_IGNORE_PATTERN = ('!OWNERS:!.svn:!.git:!.ds_store:!*.scc:.*:<dir>_*:' +
                        '!CVS:!thumbs.db:!picasa.ini:!*~:!*.d.stamp')
 HERMETIC_TIMESTAMP = (2001, 1, 1, 0, 0, 0)
@@ skipping 364 matching lines @@
       file_jsons[file_path] = ReadJson(file_path)
 
     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,

[jbudorick, 2015/09/18 18:19:38]

curious: why'd you put this in here rather than in md5_check, and why would a
client call md5_check.CallAndRecordIfStale vs build_utils.CallAndRecordIfStale?

[agrieve, 2015/09/18 18:46:19]

My reasoning:
- md5_check felt a bit like a generic module, builddeps is very
our-build-system-specific. 
- The purpose of md5_check.CallAndRecordIfStale is to check md5s. & the purpose
of this wrapper is just to eliminate copy & paste surrounding our usage of it.

I'm open to slicing it another way, but that was my thinking. You'd use
md5_check.py directly if you don't want the builddeps logic.

[jbudorick, 2015/09/23 14:56:37]

I'm concerned about:
 - having two identically-named functions where one does A and the other does
A+B confusing people, myself included
 - having the former function only used by the latter, in which case they
probably don't need to be separate (or at least don't need to both be publicly
visible)

+                         input_strings=None, output_paths=None, force=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:

[jbudorick, 2015/09/18 18:19:38]

I'm not crazy about locking option names across scripts, tbh.

[agrieve, 2015/09/18 18:46:19]

All scripts already use build_utils.AddDepfileOption() to add this option, so
the name will be consistent.
As for .stamp, there's not a helper for it, but it's on the way out anyways (not
used in GN).

+    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()
+    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)
+