author Jim Blandy <>
Tue, 24 Jun 2014 22:12:07 -0700
changeset 199513 69d61e42d5dfbf4588b72449249ff3e7f2125304
parent 198792 a6b5b538815561ac3acdb37a3575a64e35c2ee8f
child 200927 588203633ba714cc4ee0e1f03cf9844faee41e09
permissions -rwxr-xr-x
Bug 914753: Make Emacs file variable header lines correct, or at least consistent. DONTBUILD r=ehsan The -*- file variable lines -*- establish per-file settings that Emacs will pick up. This patch makes the following changes to those lines (and touches nothing else): - Never set the buffer's mode. Years ago, Emacs did not have a good JavaScript mode, so it made sense to use Java or C++ mode in .js files. However, Emacs has had js-mode for years now; it's perfectly serviceable, and is available and enabled by default in all major Emacs packagings. Selecting a mode in the -*- file variable line -*- is almost always the wrong thing to do anyway. It overrides Emacs's default choice, which is (now) reasonable; and even worse, it overrides settings the user might have made in their '.emacs' file for that file extension. It's only useful when there's something specific about that particular file that makes a particular mode appropriate. - Correctly propagate settings that establish the correct indentation level for this file: c-basic-offset and js2-basic-offset should be js-indent-level. Whatever value they're given should be preserved; different parts of our tree use different indentation styles. - We don't use tabs in Mozilla JS code. Always set indent-tabs-mode: nil. Remove tab-width: settings, at least in files that don't contain tab characters. - Remove js2-mode settings that belong in the user's .emacs file, like js2-skip-preprocessor-directives.

# 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

# The beginning of this script is both valid shell and valid python,
# such that the script starts with the shell and is reexecuted with
# the right python.
'''which' python2.7 > /dev/null && exec python2.7 "$0" "$@" || exec python "$0" "$@"

from __future__ import print_function, unicode_literals

import os
import sys

def ancestors(path):
    while path:
        yield path
        (path, child) = os.path.split(path)
        if child == "":

def load_mach(topsrcdir):
    sys.path[0:0] = [os.path.join(topsrcdir, "build")]
    import mach_bootstrap
    return mach_bootstrap.bootstrap(topsrcdir)

def main(args):
    # Check whether the current directory is within a mach src or obj dir.
    for dir_path in ancestors(os.getcwd()):
        # If we find a "mozinfo.json" file, we are in the objdir.
        mozinfo_path = os.path.join(dir_path, 'mozinfo.json')
        if os.path.isfile(mozinfo_path):
            import json
            info = json.load(open(mozinfo_path))
            if 'mozconfig' in info and 'MOZCONFIG' not in os.environ:
                # If the MOZCONFIG environment variable is not already set, set it
                # to the value from mozinfo.json.  This will tell the build system
                # to look for a config file at the path in $MOZCONFIG rather than
                # its default locations.
                # Note: subprocess requires native strings in os.environ on Windows
                os.environ[b'MOZCONFIG'] = str(info['mozconfig'])

            if 'topsrcdir' in info:
                # Continue searching for mach_bootstrap in the source directory.
                dir_path = info['topsrcdir']

        # If we find the mach bootstrap module, we are in the srcdir.
        mach_path = os.path.join(dir_path, 'build/')
        if os.path.isfile(mach_path):
            mach = load_mach(dir_path)

    print('Could not run mach: No mach source directory found.')

if __name__ == '__main__':
    if sys.platform == 'win32':
        # This is a complete hack to work around the fact that Windows
        # multiprocessing needs to import the original module (ie: this
        # file), but only works if it has a .py extension.
	# We do this by a sort of two-level function interposing. The first
	# level interposes forking.get_command_line() with our version defined
	# in my_get_command_line(). Our version of get_command_line will
	# replace the command string with the contents of the fork_interpose()
	# function to be used in the subprocess.
	# The subprocess then gets an interposed imp.find_module(), which we
	# hack up to find 'mach' without the .py extension, since we already
	# know where it is (it's us!). If we're not looking for 'mach', then
	# the original find_module will suffice.
        # See also:
        # And:
        import inspect
        from multiprocessing import forking
        global orig_command_line

        def fork_interpose():
            import imp
            import os
            orig_find_module = imp.find_module
            def my_find_module(name, dirs):
                if name == 'mach':
                    path = os.path.join(dirs[0], 'mach')
                    f = open(path)
                    return (f, path, ('', 'r', imp.PY_SOURCE))
                return orig_find_module(name, dirs)

            imp.find_module = my_find_module
            from multiprocessing.forking import main; main()

        def my_get_command_line():
            fork_code, lineno = inspect.getsourcelines(fork_interpose)
            # Remove the first line (for 'def fork_interpose():') and the three
	    # levels of indentation (12 spaces).
            fork_string = ''.join(x[12:] for x in fork_code[1:])
            cmdline = orig_command_line()
            cmdline[2] = fork_string
            return cmdline
        orig_command_line = forking.get_command_line
        forking.get_command_line = my_get_command_line