js/src/irregexp/import-irregexp.py

   1 #!/usr/bin/env python3
   2
   3 # This Source Code Form is subject to the terms of the Mozilla Public
   4 # License, v. 2.0. If a copy of the MPL was not distributed with this file,
   5 # You can obtain one at http://mozilla.org/MPL/2.0/.
   6
   7 # This script handles all the mechanical steps of importing irregexp from v8:
   8 #
   9 # 1. Acquire the source: either from github, or optionally from a local copy of v8.
  10 # 2. Copy the contents of v8/src/regexp into js/src/irregexp/imported
  11 #    - Exclude files that we have chosen not to import.
  12 # 3. While doing so, update #includes:
  13 #    - Change "src/regexp/*" to "irregexp/imported/*".
  14 #    - Remove other v8-specific headers completely.
  15 # 4. Add '#include "irregexp/RegExpShim.h" in the necessary places.
  16 # 5. Update the IRREGEXP_VERSION file to include the correct git hash.
  17 #
  18 # Usage:
  19 #  cd path/to/js/src/irregexp
  20 #  ./import-irregexp.py --path path/to/v8/src/regexp
  21 #
  22 # Alternatively, without the --path argument, import-irregexp.py will
  23 # clone v8 from github into a temporary directory.
  24 #
  25 # After running this script, changes to the shim code may be necessary
  26 # to account for changes in upstream irregexp.
  27
  28 import os
  29 import re
  30 import subprocess
  31 import sys
  32 from pathlib import Path
  33
  34
  35 def copy_and_update_includes(src_path, dst_path):
  36     # List of header files that need to include the shim header
  37     need_shim = [
  38         "property-sequences.h",
  39         "regexp-ast.h",
  40         "regexp-bytecode-peephole.h",
  41         "regexp-bytecodes.h",
  42         "regexp-dotprinter.h",
  43         "regexp-error.h",
  44         "regexp.h",
  45         "regexp-macro-assembler.h",
  46         "regexp-parser.h",
  47         "regexp-stack.h",
  48         "special-case.h",
  49     ]
  50
  51     src = open(str(src_path), "r")
  52     dst = open(str(dst_path), "w")
  53
  54     # 1. Rewrite includes of V8 regexp headers:
  55     #    Note that we exclude regexp-flags.h and provide our own definition.
  56     regexp_include = re.compile('#include "src/regexp(?!/regexp-flags.h)')
  57     regexp_include_new = '#include "irregexp/imported'
  58
  59     # 2. Remove includes of other V8 headers
  60     other_include = re.compile('#include "src/')
  61
  62     # 3. If needed, add '#include "irregexp/RegExpShim.h"'.
  63     #    Note: We get a little fancy to ensure that header files are
  64     #    in alphabetic order. `need_to_add_shim` is true if we still
  65     #    have to add the shim header in this file. `adding_shim_now`
  66     #    is true if we have found a '#include "src/*' and we are just
  67     #    waiting to find an empty line so that we can insert the shim
  68     #    header in the right place.
  69     need_to_add_shim = src_path.name in need_shim
  70     adding_shim_now = False
  71
  72     for line in src:
  73         if adding_shim_now:
  74             if line == "\n":
  75                 dst.write('#include "irregexp/RegExpShim.h"\n')
  76                 need_to_add_shim = False
  77                 adding_shim_now = False
  78
  79         if regexp_include.search(line):
  80             dst.write(re.sub(regexp_include, regexp_include_new, line))
  81         elif other_include.search(line):
  82             if need_to_add_shim:
  83                 adding_shim_now = True
  84         else:
  85             dst.write(line)
  86
  87
  88 def import_from(srcdir, dstdir):
  89     excluded = [
  90         "DIR_METADATA",
  91         "OWNERS",
  92         "regexp.cc",
  93         "regexp-flags.h",
  94         "regexp-utils.cc",
  95         "regexp-utils.h",
  96         "regexp-macro-assembler-arch.h",
  97     ]
  98
  99     for file in srcdir.iterdir():
 100         if file.is_dir():
 101             continue
 102         if str(file.name) in excluded:
 103             continue
 104         copy_and_update_includes(file, dstdir / "imported" / file.name)
 105
 106
 107 if __name__ == "__main__":
 108     import argparse
 109     import tempfile
 110
 111     # This script should be run from js/src/irregexp to work correctly.
 112     current_path = Path(os.getcwd())
 113     expected_path = "js/src/irregexp"
 114     if not current_path.match(expected_path):
 115         raise RuntimeError("%s must be run from %s" % (sys.argv[0], expected_path))
 116
 117     parser = argparse.ArgumentParser(description="Import irregexp from v8")
 118     parser.add_argument("-p", "--path", help="path to v8/src/regexp", required=False)
 119     args = parser.parse_args()
 120
 121     if args.path:
 122         src_path = Path(args.path)
 123         provided_path = "the command-line"
 124     elif "TASK_ID" in os.environ:
 125         src_path = Path("/builds/worker/v8/")
 126         subprocess.run("git pull origin master", shell=True, cwd=src_path)
 127
 128         src_path = Path("/builds/worker/v8/src/regexp")
 129         provided_path = "the hardcoded path in the taskcluster image"
 130     elif "V8_GIT" in os.environ:
 131         src_path = Path(os.environ["V8_GIT"])
 132         provided_path = "the V8_GIT environment variable"
 133     else:
 134         tempdir = tempfile.TemporaryDirectory()
 135         v8_git = "https://github.com/v8/v8.git"
 136         clone = "git clone --depth 1 %s %s" % (v8_git, tempdir.name)
 137         os.system(clone)
 138         src_path = Path(tempdir.name) / "src/regexp"
 139         provided_path = "the temporary git checkout"
 140
 141     if not (src_path / "regexp.h").exists():
 142         print("Could not find regexp.h in the path provided from", provided_path)
 143         print("Usage:\n  import-irregexp.py [--path <path/to/v8/src/regexp>]")
 144         sys.exit(1)
 145
 146     if "MACH_VENDOR" not in os.environ:
 147         print(
 148             "Running this script outside ./mach vendor is not recommended - ",
 149             "You will need to update moz.yaml manually",
 150         )
 151         print("We recommend instead `./mach vendor js/src/irregexp/moz.yaml`")
 152         response = input("Type Y to continue... ")
 153         if response.lower() != "y":
 154             sys.exit(1)
 155
 156     import_from(src_path, current_path)