| #!/usr/bin/env python |
| # Copyright 2015 The Chromium Authors. All rights reserved. |
| # Use of this source code is governed by a BSD-style license that can be |
| # found in the LICENSE file. |
| |
| """Runs 'ld -shared' and generates a .TOC file that's untouched when unchanged. |
| |
| This script exists to avoid using complex shell commands in |
| gcc_toolchain.gni's tool("solink"), in case the host running the compiler |
| does not have a POSIX-like shell (e.g. Windows). |
| """ |
| |
| import argparse |
| import os |
| import re |
| import subprocess |
| import sys |
| |
| |
| # When running on a Windows host and using a toolchain whose tools are |
| # actually wrapper scripts (i.e. .bat files on Windows) rather than binary |
| # executables, the "command" to run has to be prefixed with this magic. |
| # The GN toolchain definitions take care of that for when GN/Ninja is |
| # running the tool directly. When that command is passed in to this |
| # script, it appears as a unitary string but needs to be split up so that |
| # just 'cmd' is the actual command given to Python's subprocess module. |
| BAT_PREFIX = 'cmd /c call ' |
| |
| def CommandToRun(command): |
| if command[0].startswith(BAT_PREFIX): |
| command = command[0].split(None, 3) + command[1:] |
| return command |
| |
| |
| def CollectSONAME(args): |
| """Replaces: readelf -d $sofile | grep SONAME""" |
| toc = '' |
| readelf = subprocess.Popen(CommandToRun([args.readelf, '-d', args.sofile]), |
| stdout=subprocess.PIPE, bufsize=-1) |
| for line in readelf.stdout: |
| if 'SONAME' in line: |
| toc += line |
| return readelf.wait(), toc |
| |
| |
| def CollectDynSym(args): |
| """Replaces: nm --format=posix -g -D $sofile | cut -f1-2 -d' '""" |
| toc = '' |
| nm = subprocess.Popen(CommandToRun([ |
| args.nm, '--format=posix', '-g', '-D', args.sofile]), |
| stdout=subprocess.PIPE, bufsize=-1) |
| for line in nm.stdout: |
| toc += ' '.join(line.split(' ', 2)[:2]) + '\n' |
| return nm.wait(), toc |
| |
| |
| def CollectTOC(args): |
| result, toc = CollectSONAME(args) |
| if result == 0: |
| result, dynsym = CollectDynSym(args) |
| toc += dynsym |
| return result, toc |
| |
| |
| def UpdateTOC(tocfile, toc): |
| if os.path.exists(tocfile): |
| old_toc = open(tocfile, 'r').read() |
| else: |
| old_toc = None |
| if toc != old_toc: |
| open(tocfile, 'w').write(toc) |
| |
| |
| def main(): |
| parser = argparse.ArgumentParser(description=__doc__) |
| parser.add_argument('--readelf', |
| required=True, |
| help='The readelf binary to run', |
| metavar='PATH') |
| parser.add_argument('--nm', |
| required=True, |
| help='The nm binary to run', |
| metavar='PATH') |
| parser.add_argument('--strip', |
| help='The strip binary to run', |
| metavar='PATH') |
| parser.add_argument('--sofile', |
| required=True, |
| help='Shared object file produced by linking command', |
| metavar='FILE') |
| parser.add_argument('--tocfile', |
| required=True, |
| help='Output table-of-contents file', |
| metavar='FILE') |
| parser.add_argument('--output', |
| required=True, |
| help='Final output shared object file', |
| metavar='FILE') |
| parser.add_argument('command', nargs='+', |
| help='Linking command') |
| args = parser.parse_args() |
| |
| # First, run the actual link. |
| result = subprocess.call(CommandToRun(args.command)) |
| if result != 0: |
| return result |
| |
| # Next, generate the contents of the TOC file. |
| result, toc = CollectTOC(args) |
| if result != 0: |
| return result |
| |
| # If there is an existing TOC file with identical contents, leave it alone. |
| # Otherwise, write out the TOC file. |
| UpdateTOC(args.tocfile, toc) |
| |
| # Finally, strip the linked shared object file (if desired). |
| if args.strip: |
| result = subprocess.call(CommandToRun([args.strip, '--strip-unneeded', |
| '-o', args.output, args.sofile])) |
| |
| return result |
| |
| |
| if __name__ == "__main__": |
| sys.exit(main()) |