gecko/build/ConfigStatus.py
Gregory Szorc ba2d03eb97 Bug 948787 - Print diffs during config.status; r=glandium
Build system developers commonly need to see what changes have on the
generated build files. We often put our objdir under version control and
diff commits before and after running config.status.

This patch adds a --diff option to config.status that will print diffs
of changes made during config.status. This functionality is implemented
on top of FileAvoidWrite, using Python's built-in diffing library.

While display of diffs is opt-in, diffs are always being captured when
config.status runs. There could be an unwanted performance regression
from this. Because diffs are only computed if files change and most
files don't change during most config.status runs, this greatly reduces
the surface area of the concern. The area for largest concern is clobber
builds. On my machine, I measured an increase of 0.2 to 0.3s from 2.0s.
While this is 10-15%, the total time is so small that I don't feel
snaking a "capture diff" flag through the build system is worth the
effort. This would make a decent followup bug if this turns out to be a
problem in the future.

I also snuck in a change to reindent all-tests.json because displaying
diffs for this massive 11MB all-in-one-line JSON file results in an
extremely large string being printed to my terminal.

--HG--
extra : rebase_source : c0f7ff69cad282e63a050e67f156dbe96b49a142
2013-12-11 13:06:56 +09:00

107 lines
4.3 KiB
Python

# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
# Combined with build/autoconf/config.status.m4, ConfigStatus is an almost
# drop-in replacement for autoconf 2.13's config.status, with features
# borrowed from autoconf > 2.5, and additional features.
from __future__ import print_function
import logging
import os
import sys
from optparse import OptionParser
from mach.logging import LoggingManager
from mozbuild.backend.configenvironment import ConfigEnvironment
from mozbuild.backend.recursivemake import RecursiveMakeBackend
from mozbuild.frontend.emitter import TreeMetadataEmitter
from mozbuild.frontend.reader import BuildReader
from mozbuild.mozinfo import write_mozinfo
log_manager = LoggingManager()
def config_status(topobjdir='.', topsrcdir='.',
defines=[], non_global_defines=[], substs=[]):
'''Main function, providing config.status functionality.
Contrary to config.status, it doesn't use CONFIG_FILES or CONFIG_HEADERS
variables.
Without the -n option, this program acts as config.status and considers
the current directory as the top object directory, even when config.status
is in a different directory. It will, however, treat the directory
containing config.status as the top object directory with the -n option.
The --recheck option, like with the original config.status, runs configure
again, with the options given in the "ac_configure_args" subst.
The options to this function are passed when creating the
ConfigEnvironment. These lists, as well as the actual wrapper script
around this function, are meant to be generated by configure.
See build/autoconf/config.status.m4.
'''
if 'CONFIG_FILES' in os.environ:
raise Exception('Using the CONFIG_FILES environment variable is not '
'supported.')
if 'CONFIG_HEADERS' in os.environ:
raise Exception('Using the CONFIG_HEADERS environment variable is not '
'supported.')
if not os.path.isabs(topsrcdir):
raise Exception('topsrcdir must be defined as an absolute directory: '
'%s' % topsrcdir)
parser = OptionParser()
parser.add_option('--recheck', dest='recheck', action='store_true',
help='update config.status by reconfiguring in the same conditions')
parser.add_option('-v', '--verbose', dest='verbose', action='store_true',
help='display verbose output')
parser.add_option('-n', dest='not_topobjdir', action='store_true',
help='do not consider current directory as top object directory')
parser.add_option('-d', '--diff', action='store_true',
help='print diffs of changed files.')
options, args = parser.parse_args()
# Without -n, the current directory is meant to be the top object directory
if not options.not_topobjdir:
topobjdir = os.path.abspath('.')
env = ConfigEnvironment(topsrcdir, topobjdir, defines=defines,
non_global_defines=non_global_defines, substs=substs)
# mozinfo.json only needs written if configure changes and configure always
# passes this environment variable.
if 'WRITE_MOZINFO' in os.environ:
write_mozinfo(os.path.join(topobjdir, 'mozinfo.json'), env, os.environ)
reader = BuildReader(env)
emitter = TreeMetadataEmitter(env)
backend = RecursiveMakeBackend(env)
# This won't actually do anything because of the magic of generators.
definitions = emitter.emit(reader.read_topsrcdir())
if options.recheck:
# Execute configure from the top object directory
os.chdir(topobjdir)
os.execlp('sh', 'sh', '-c', ' '.join([os.path.join(topsrcdir, 'configure'), env.substs['ac_configure_args'], '--no-create', '--no-recursion']))
log_level = logging.DEBUG if options.verbose else logging.INFO
log_manager.add_terminal_logging(level=log_level)
log_manager.enable_unstructured()
print('Reticulating splines...', file=sys.stderr)
summary = backend.consume(definitions)
for line in summary.summaries():
print(line, file=sys.stderr)
if options.diff:
for path, diff in sorted(summary.file_diffs.items()):
print(diff)