diff options
Diffstat (limited to 'third_party/libwebrtc/build/toolchain/gcc_solink_wrapper.py')
-rwxr-xr-x | third_party/libwebrtc/build/toolchain/gcc_solink_wrapper.py | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/third_party/libwebrtc/build/toolchain/gcc_solink_wrapper.py b/third_party/libwebrtc/build/toolchain/gcc_solink_wrapper.py new file mode 100755 index 0000000000..39aef4d1e9 --- /dev/null +++ b/third_party/libwebrtc/build/toolchain/gcc_solink_wrapper.py @@ -0,0 +1,198 @@ +#!/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 shlex +import subprocess +import sys + +import wrapper_utils + + +def CollectSONAME(args): + """Replaces: readelf -d $sofile | grep SONAME""" + toc = '' + readelf = subprocess.Popen(wrapper_utils.CommandToRun( + [args.readelf, '-d', args.sofile]), + stdout=subprocess.PIPE, + bufsize=-1, + universal_newlines=True) + for line in readelf.stdout: + if 'SONAME' in line: + toc += line + return readelf.wait(), toc + + +def CollectDynSym(args): + """Replaces: nm --format=posix -g -D -p $sofile | cut -f1-2 -d' '""" + toc = '' + nm = subprocess.Popen(wrapper_utils.CommandToRun( + [args.nm, '--format=posix', '-g', '-D', '-p', args.sofile]), + stdout=subprocess.PIPE, + bufsize=-1, + universal_newlines=True) + 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 CollectInputs(out, args): + for x in args: + if x.startswith('@'): + with open(x[1:]) as rsp: + CollectInputs(out, shlex.split(rsp.read())) + elif not x.startswith('-') and (x.endswith('.o') or x.endswith('.a')): + out.write(x) + out.write('\n') + + +def InterceptFlag(flag, command): + ret = flag in command + if ret: + command.remove(flag) + return ret + + +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('--dwp', help='The dwp 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('--map-file', + help=('Use --Wl,-Map to generate a map file. Will be ' + 'gzipped if extension ends with .gz'), + 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() + + # Work-around for gold being slow-by-default. http://crbug.com/632230 + fast_env = dict(os.environ) + fast_env['LC_ALL'] = 'C' + + # Extract flags passed through ldflags but meant for this script. + # https://crbug.com/954311 tracks finding a better way to plumb these. + link_only = InterceptFlag('--link-only', args.command) + collect_inputs_only = InterceptFlag('--collect-inputs-only', args.command) + + # If only linking, we are likely generating a partitioned .so that will be + # split apart later. In that case: + # + # - The TOC file optimization isn't useful, because the partition libraries + # must always be re-extracted if the combined library changes (and nothing + # should be depending on the combined library's dynamic symbol table). + # - Stripping isn't necessary, because the combined library is not used in + # production or published. + # + # Both of these operations could still be done, they're needless work, and + # tools would need to be updated to handle and/or not complain about + # partitioned libraries. Instead, to keep Ninja happy, simply create dummy + # files for the TOC and stripped lib. + if link_only or collect_inputs_only: + open(args.output, 'w').close() + open(args.tocfile, 'w').close() + if args.dwp: + open(args.sofile + '.dwp', 'w').close() + + # Instead of linking, records all inputs to a file. This is used by + # enable_resource_allowlist_generation in order to avoid needing to + # link (which is slow) to build the resources allowlist. + if collect_inputs_only: + with open(args.sofile, 'w') as f: + CollectInputs(f, args.command) + if args.map_file: + open(args.map_file, 'w').close() + return 0 + + # First, run the actual link. + command = wrapper_utils.CommandToRun(args.command) + result = wrapper_utils.RunLinkWithOptionalMapFile(command, + env=fast_env, + map_file=args.map_file) + + if result != 0 or link_only: + return result + + # If dwp is set, then package debug info for this SO. + dwp_proc = None + if args.dwp: + # Suppress output here because it doesn't seem to be useful. The most + # common error is a segfault, which will happen if files are missing. + with open(os.devnull, "w") as devnull: + dwp_proc = subprocess.Popen(wrapper_utils.CommandToRun( + [args.dwp, '-e', args.sofile, '-o', args.sofile + '.dwp']), + stdout=devnull, + stderr=subprocess.STDOUT) + + # 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(wrapper_utils.CommandToRun( + [args.strip, '-o', args.output, args.sofile])) + + if dwp_proc: + dwp_result = dwp_proc.wait() + if dwp_result != 0: + return dwp_result + + return result + + +if __name__ == "__main__": + sys.exit(main()) |