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Diffstat (limited to 'mesonbuild/scripts/symbolextractor.py')
| -rw-r--r-- | mesonbuild/scripts/symbolextractor.py | 333 |
1 files changed, 333 insertions, 0 deletions
diff --git a/mesonbuild/scripts/symbolextractor.py b/mesonbuild/scripts/symbolextractor.py new file mode 100644 index 0000000..08d839b --- /dev/null +++ b/mesonbuild/scripts/symbolextractor.py @@ -0,0 +1,333 @@ +# Copyright 2013-2016 The Meson development team + +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at + +# http://www.apache.org/licenses/LICENSE-2.0 + +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +# This script extracts the symbols of a given shared library +# into a file. If the symbols have not changed, the file is not +# touched. This information is used to skip link steps if the +# ABI has not changed. + +# This file is basically a reimplementation of +# http://cgit.freedesktop.org/libreoffice/core/commit/?id=3213cd54b76bc80a6f0516aac75a48ff3b2ad67c +from __future__ import annotations + +import typing as T +import os, sys +from .. import mesonlib +from .. import mlog +from ..mesonlib import Popen_safe +import argparse + +parser = argparse.ArgumentParser() + +parser.add_argument('--cross-host', default=None, dest='cross_host', + help='cross compilation host platform') +parser.add_argument('args', nargs='+') + +TOOL_WARNING_FILE = None +RELINKING_WARNING = 'Relinking will always happen on source changes.' + +def dummy_syms(outfilename: str) -> None: + """Just touch it so relinking happens always.""" + with open(outfilename, 'w', encoding='utf-8'): + pass + +def write_if_changed(text: str, outfilename: str) -> None: + try: + with open(outfilename, encoding='utf-8') as f: + oldtext = f.read() + if text == oldtext: + return + except FileNotFoundError: + pass + with open(outfilename, 'w', encoding='utf-8') as f: + f.write(text) + +def print_tool_warning(tools: T.List[str], msg: str, stderr: T.Optional[str] = None) -> None: + if os.path.exists(TOOL_WARNING_FILE): + return + m = f'{tools!r} {msg}. {RELINKING_WARNING}' + if stderr: + m += '\n' + stderr + mlog.warning(m) + # Write it out so we don't warn again + with open(TOOL_WARNING_FILE, 'w', encoding='utf-8'): + pass + +def get_tool(name: str) -> T.List[str]: + evar = name.upper() + if evar in os.environ: + import shlex + return shlex.split(os.environ[evar]) + return [name] + +def call_tool(name: str, args: T.List[str], **kwargs: T.Any) -> str: + tool = get_tool(name) + try: + p, output, e = Popen_safe(tool + args, **kwargs) + except FileNotFoundError: + print_tool_warning(tool, 'not found') + return None + except PermissionError: + print_tool_warning(tool, 'not usable') + return None + if p.returncode != 0: + print_tool_warning(tool, 'does not work', e) + return None + return output + +def call_tool_nowarn(tool: T.List[str], **kwargs: T.Any) -> T.Tuple[str, str]: + try: + p, output, e = Popen_safe(tool, **kwargs) + except FileNotFoundError: + return None, '{!r} not found\n'.format(tool[0]) + except PermissionError: + return None, '{!r} not usable\n'.format(tool[0]) + if p.returncode != 0: + return None, e + return output, None + +def gnu_syms(libfilename: str, outfilename: str) -> None: + # Get the name of the library + output = call_tool('readelf', ['-d', libfilename]) + if not output: + dummy_syms(outfilename) + return + result = [x for x in output.split('\n') if 'SONAME' in x] + assert len(result) <= 1 + # Get a list of all symbols exported + output = call_tool('nm', ['--dynamic', '--extern-only', '--defined-only', + '--format=posix', libfilename]) + if not output: + dummy_syms(outfilename) + return + for line in output.split('\n'): + if not line: + continue + line_split = line.split() + entry = line_split[0:2] + # Store the size of symbols pointing to data objects so we relink + # when those change, which is needed because of copy relocations + # https://github.com/mesonbuild/meson/pull/7132#issuecomment-628353702 + if line_split[1].upper() in {'B', 'G', 'D'} and len(line_split) >= 4: + entry += [line_split[3]] + result += [' '.join(entry)] + write_if_changed('\n'.join(result) + '\n', outfilename) + +def solaris_syms(libfilename: str, outfilename: str) -> None: + # gnu_syms() works with GNU nm & readelf, not Solaris nm & elfdump + origpath = os.environ['PATH'] + try: + os.environ['PATH'] = '/usr/gnu/bin:' + origpath + gnu_syms(libfilename, outfilename) + finally: + os.environ['PATH'] = origpath + +def osx_syms(libfilename: str, outfilename: str) -> None: + # Get the name of the library + output = call_tool('otool', ['-l', libfilename]) + if not output: + dummy_syms(outfilename) + return + arr = output.split('\n') + for (i, val) in enumerate(arr): + if 'LC_ID_DYLIB' in val: + match = i + break + result = [arr[match + 2], arr[match + 5]] # Libreoffice stores all 5 lines but the others seem irrelevant. + # Get a list of all symbols exported + output = call_tool('nm', ['--extern-only', '--defined-only', + '--format=posix', libfilename]) + if not output: + dummy_syms(outfilename) + return + result += [' '.join(x.split()[0:2]) for x in output.split('\n')] + write_if_changed('\n'.join(result) + '\n', outfilename) + +def openbsd_syms(libfilename: str, outfilename: str) -> None: + # Get the name of the library + output = call_tool('readelf', ['-d', libfilename]) + if not output: + dummy_syms(outfilename) + return + result = [x for x in output.split('\n') if 'SONAME' in x] + assert len(result) <= 1 + # Get a list of all symbols exported + output = call_tool('nm', ['-D', '-P', '-g', libfilename]) + if not output: + dummy_syms(outfilename) + return + # U = undefined (cope with the lack of --defined-only option) + result += [' '.join(x.split()[0:2]) for x in output.split('\n') if x and not x.endswith('U ')] + write_if_changed('\n'.join(result) + '\n', outfilename) + +def freebsd_syms(libfilename: str, outfilename: str) -> None: + # Get the name of the library + output = call_tool('readelf', ['-d', libfilename]) + if not output: + dummy_syms(outfilename) + return + result = [x for x in output.split('\n') if 'SONAME' in x] + assert len(result) <= 1 + # Get a list of all symbols exported + output = call_tool('nm', ['--dynamic', '--extern-only', '--defined-only', + '--format=posix', libfilename]) + if not output: + dummy_syms(outfilename) + return + + result += [' '.join(x.split()[0:2]) for x in output.split('\n')] + write_if_changed('\n'.join(result) + '\n', outfilename) + +def cygwin_syms(impfilename: str, outfilename: str) -> None: + # Get the name of the library + output = call_tool('dlltool', ['-I', impfilename]) + if not output: + dummy_syms(outfilename) + return + result = [output] + # Get the list of all symbols exported + output = call_tool('nm', ['--extern-only', '--defined-only', + '--format=posix', impfilename]) + if not output: + dummy_syms(outfilename) + return + for line in output.split('\n'): + if ' T ' not in line: + continue + result.append(line.split(maxsplit=1)[0]) + write_if_changed('\n'.join(result) + '\n', outfilename) + +def _get_implib_dllname(impfilename: str) -> T.Tuple[T.List[str], str]: + all_stderr = '' + # First try lib.exe, which is provided by MSVC. Then llvm-lib.exe, by LLVM + # for clang-cl. + # + # We cannot call get_tool on `lib` because it will look at the `LIB` env + # var which is the list of library paths MSVC will search for import + # libraries while linking. + for lib in (['lib'], get_tool('llvm-lib')): + output, e = call_tool_nowarn(lib + ['-list', impfilename]) + if output: + # The output is a list of DLLs that each symbol exported by the import + # library is available in. We only build import libraries that point to + # a single DLL, so we can pick any of these. Pick the last one for + # simplicity. Also skip the last line, which is empty. + return output.split('\n')[-2:-1], None + all_stderr += e + # Next, try dlltool.exe which is provided by MinGW + output, e = call_tool_nowarn(get_tool('dlltool') + ['-I', impfilename]) + if output: + return [output], None + all_stderr += e + return ([], all_stderr) + +def _get_implib_exports(impfilename: str) -> T.Tuple[T.List[str], str]: + all_stderr = '' + # Force dumpbin.exe to use en-US so we can parse its output + env = os.environ.copy() + env['VSLANG'] = '1033' + output, e = call_tool_nowarn(get_tool('dumpbin') + ['-exports', impfilename], env=env) + if output: + lines = output.split('\n') + start = lines.index('File Type: LIBRARY') + end = lines.index(' Summary') + return lines[start:end], None + all_stderr += e + # Next, try llvm-nm.exe provided by LLVM, then nm.exe provided by MinGW + for nm in ('llvm-nm', 'nm'): + output, e = call_tool_nowarn(get_tool(nm) + ['--extern-only', '--defined-only', + '--format=posix', impfilename]) + if output: + result = [] + for line in output.split('\n'): + if ' T ' not in line or line.startswith('.text'): + continue + result.append(line.split(maxsplit=1)[0]) + return result, None + all_stderr += e + return ([], all_stderr) + +def windows_syms(impfilename: str, outfilename: str) -> None: + # Get the name of the library + result, e = _get_implib_dllname(impfilename) + if not result: + print_tool_warning(['lib', 'llvm-lib', 'dlltool'], 'do not work or were not found', e) + dummy_syms(outfilename) + return + # Get a list of all symbols exported + symbols, e = _get_implib_exports(impfilename) + if not symbols: + print_tool_warning(['dumpbin', 'llvm-nm', 'nm'], 'do not work or were not found', e) + dummy_syms(outfilename) + return + result += symbols + write_if_changed('\n'.join(result) + '\n', outfilename) + +def gen_symbols(libfilename: str, impfilename: str, outfilename: str, cross_host: str) -> None: + if cross_host is not None: + # In case of cross builds just always relink. In theory we could + # determine the correct toolset, but we would need to use the correct + # `nm`, `readelf`, etc, from the cross info which requires refactoring. + dummy_syms(outfilename) + elif mesonlib.is_linux() or mesonlib.is_hurd(): + gnu_syms(libfilename, outfilename) + elif mesonlib.is_osx(): + osx_syms(libfilename, outfilename) + elif mesonlib.is_openbsd(): + openbsd_syms(libfilename, outfilename) + elif mesonlib.is_freebsd(): + freebsd_syms(libfilename, outfilename) + elif mesonlib.is_netbsd(): + freebsd_syms(libfilename, outfilename) + elif mesonlib.is_windows(): + if os.path.isfile(impfilename): + windows_syms(impfilename, outfilename) + else: + # No import library. Not sure how the DLL is being used, so just + # rebuild everything that links to it every time. + dummy_syms(outfilename) + elif mesonlib.is_cygwin(): + if os.path.isfile(impfilename): + cygwin_syms(impfilename, outfilename) + else: + # No import library. Not sure how the DLL is being used, so just + # rebuild everything that links to it every time. + dummy_syms(outfilename) + elif mesonlib.is_sunos(): + solaris_syms(libfilename, outfilename) + else: + if not os.path.exists(TOOL_WARNING_FILE): + mlog.warning('Symbol extracting has not been implemented for this ' + 'platform. ' + RELINKING_WARNING) + # Write it out so we don't warn again + with open(TOOL_WARNING_FILE, 'w', encoding='utf-8'): + pass + dummy_syms(outfilename) + +def run(args: T.List[str]) -> int: + global TOOL_WARNING_FILE # pylint: disable=global-statement + options = parser.parse_args(args) + if len(options.args) != 4: + print('symbolextractor.py <shared library file> <import library> <output file>') + sys.exit(1) + privdir = os.path.join(options.args[0], 'meson-private') + TOOL_WARNING_FILE = os.path.join(privdir, 'symbolextractor_tool_warning_printed') + libfile = options.args[1] + impfile = options.args[2] # Only used on Windows + outfile = options.args[3] + gen_symbols(libfile, impfile, outfile, options.cross_host) + return 0 + +if __name__ == '__main__': + sys.exit(run(sys.argv[1:])) |