From 5c60023cb8ad6f07927bd53f30c90873d07b300f Mon Sep 17 00:00:00 2001 From: Simon Sapin Date: Fri, 27 Sep 2019 06:37:54 +0200 Subject: WebIDL codegen: Replace cmake with a single Python script MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When playing around with Cargo’s new timing visualization: https://internals.rust-lang.org/t/exploring-crate-graph-build-times-with-cargo-build-ztimings/10975/21 … I was surprised to see the `script` crate’s build script take 76 seconds. I did not expect WebIDL bindings generation to be *that* computationally intensive. It turns out almost all of this time is overhead. The build script uses CMake to generate bindings for each WebIDL file in parallel, but that causes a lot of work to be repeated 366 times: * Starting up a Python VM * Importing (parts of) the Python standard library * Importing ~16k lines of our Python code * Recompiling the latter to bytecode, since we used `python -B` to disable writing `.pyc` file * Deserializing with `cPickle` and recreating in memory the results of parsing all WebIDL files ---- This commit remove the use of CMake and cPickle for the `script` crate. Instead, all WebIDL bindings generation is done sequentially in a single Python process. This takes 2 to 3 seconds. --- .../script/dom/bindings/codegen/pythonpath.py | 61 ---------------------- 1 file changed, 61 deletions(-) delete mode 100644 components/script/dom/bindings/codegen/pythonpath.py (limited to 'components/script/dom/bindings/codegen/pythonpath.py') diff --git a/components/script/dom/bindings/codegen/pythonpath.py b/components/script/dom/bindings/codegen/pythonpath.py deleted file mode 100644 index 67739c3625f..00000000000 --- a/components/script/dom/bindings/codegen/pythonpath.py +++ /dev/null @@ -1,61 +0,0 @@ -# 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 https://mozilla.org/MPL/2.0/. - -""" -Run a python script, adding extra directories to the python path. -""" - - -def main(args): - def usage(): - print >>sys.stderr, "pythonpath.py -I directory script.py [args...]" - sys.exit(150) - - paths = [] - - while True: - try: - arg = args[0] - except IndexError: - usage() - - if arg == '-I': - args.pop(0) - try: - path = args.pop(0) - except IndexError: - usage() - - paths.append(os.path.abspath(path)) - continue - - if arg.startswith('-I'): - paths.append(os.path.abspath(args.pop(0)[2:])) - continue - - if arg.startswith('-D'): - os.chdir(args.pop(0)[2:]) - continue - - break - - script = args[0] - - sys.path[0:0] = [os.path.abspath(os.path.dirname(script))] + paths - sys.argv = args - sys.argc = len(args) - - frozenglobals['__name__'] = '__main__' - frozenglobals['__file__'] = script - - execfile(script, frozenglobals) - -# Freeze scope here ... why this makes things work I have no idea ... -frozenglobals = globals() - -import sys -import os - -if __name__ == '__main__': - main(sys.argv[1:]) -- cgit v1.2.3