import-irregexp.py

Enable keyboard shortcuts

#!/usr/bin/env python3

# 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/.

# This script handles all the mechanical steps of importing irregexp from v8:

# 1. Acquire the source: either from github, or optionally from a local copy of v8.

# 2. Copy the contents of v8/src/regexp into js/src/irregexp/imported

#    - Exclude files that we have chosen not to import.

# 3. While doing so, update #includes:

#    - Change "src/regexp/*" to "irregexp/imported/*".

#    - Remove other v8-specific headers completely.

# 4. Add '#include "irregexp/RegExpShim.h" in the necessary places.

# 5. Update the IRREGEXP_VERSION file to include the correct git hash.

# Usage:

#  cd path/to/js/src/irregexp

#  ./import-irregexp.py --path path/to/v8/src/regexp

# Alternatively, without the --path argument, import-irregexp.py will

# clone v8 from github into a temporary directory.

# After running this script, changes to the shim code may be necessary

# to account for changes in upstream irregexp.

import os

import re

import subprocess

import sys

from pathlib import Path

def copy_and_update_includes(src_path, dst_path):

    # List of header files that need to include the shim header

    need_shim = [

        "property-sequences.h",

        "regexp-ast.h",

        "regexp-bytecode-peephole.h",

        "regexp-bytecodes.h",

        "regexp-dotprinter.h",

        "regexp-error.h",

        "regexp.h",

        "regexp-macro-assembler.h",

        "regexp-parser.h",

        "regexp-stack.h",

        "special-case.h",

    src = open(str(src_path), "r")

    dst = open(str(dst_path), "w")

    # 1. Rewrite includes of V8 regexp headers:

    #    Note that we exclude several headers and provide our own definitions.

    excluded = "|".join(["flags", "utils", "result-vector"])

    regexp_include = re.compile(f'#include "src/regexp(?!/regexp-({excluded}).h)')

    regexp_include_new = '#include "irregexp/imported'

    # 2. Remove includes of other V8 headers

    other_include = re.compile('#include "src/')

    # 3. If needed, add '#include "irregexp/RegExpShim.h"'.

    #    Note: We get a little fancy to ensure that header files are

    #    in alphabetic order. `need_to_add_shim` is true if we still

    #    have to add the shim header in this file. `adding_shim_now`

    #    is true if we have found a '#include "src/*' and we are just

    #    waiting to find an empty line so that we can insert the shim

    #    header in the right place.

    need_to_add_shim = src_path.name in need_shim

    adding_shim_now = False

    for line in src:

        if adding_shim_now:

            if line == "\n":

                dst.write('#include "irregexp/RegExpShim.h"\n')

                need_to_add_shim = False

                adding_shim_now = False

        if regexp_include.search(line):

            dst.write(re.sub(regexp_include, regexp_include_new, line))

        elif other_include.search(line):

            if need_to_add_shim:

                adding_shim_now = True

        else:

            dst.write(line)

def import_from(srcdir, dstdir):

    excluded = [

        "DIR_METADATA",

        "OWNERS",

        "regexp.cc",

        "regexp-flags.h",

        "regexp-result-vector.cc",

        "regexp-result-vector.h",

        "regexp-utils.cc",

        "regexp-utils.h",

        "regexp-macro-assembler-arch.h",

    for file in srcdir.iterdir():

        if file.is_dir():

            continue

        if str(file.name) in excluded:

            continue

        copy_and_update_includes(file, dstdir / "imported" / file.name)

if __name__ == "__main__":

    import argparse

    import tempfile

    # This script should be run from js/src/irregexp to work correctly.

    current_path = Path(os.getcwd())

    expected_path = "js/src/irregexp"

    if not current_path.match(expected_path):

        raise RuntimeError("%s must be run from %s" % (sys.argv[0], expected_path))

    parser = argparse.ArgumentParser(description="Import irregexp from v8")

    parser.add_argument("-p", "--path", help="path to v8/src/regexp", required=False)

    args = parser.parse_args()

    if args.path:

        src_path = Path(args.path)

        provided_path = "the command-line"

    elif "TASK_ID" in os.environ:

        src_path = Path("/builds/worker/v8/")

        subprocess.run("git pull origin master", shell=True, cwd=src_path)

        src_path = Path("/builds/worker/v8/src/regexp")

        provided_path = "the hardcoded path in the taskcluster image"

    elif "V8_GIT" in os.environ:

        src_path = Path(os.environ["V8_GIT"])

        provided_path = "the V8_GIT environment variable"

    else:

        tempdir = tempfile.TemporaryDirectory()

        v8_git = "https://github.com/v8/v8.git"

        clone = "git clone --depth 1 %s %s" % (v8_git, tempdir.name)

        os.system(clone)

        src_path = Path(tempdir.name) / "src/regexp"

        provided_path = "the temporary git checkout"

    if not (src_path / "regexp.h").exists():

        print("Could not find regexp.h in the path provided from", provided_path)

        print("Usage:\n  import-irregexp.py [--path <path/to/v8/src/regexp>]")

        sys.exit(1)

    if "MACH_VENDOR" not in os.environ:

        print(

            "Running this script outside ./mach vendor is not recommended - ",

            "You will need to update moz.yaml manually",

        print("We recommend instead `./mach vendor js/src/irregexp/moz.yaml`")

        response = input("Type Y to continue... ")

        if response.lower() != "y":

            sys.exit(1)

    import_from(src_path, current_path)