Message ID | 87imgx2tur.fsf@mid.deneb.enyo.de |
---|---|
State | New |
Headers | show |
Series | [v2] Add scripts/move-symbol-to-libc.py | expand |
* Florian Weimer: > This helper script can be used to move symbols to libc.abilist across > all architectures, while preserving their symbol version. Ping. This patch still needs review: <https://sourceware.org/pipermail/libc-alpha/2020-May/113995.html> Thanks, Florian
On 15/05/2020 10:47, Florian Weimer wrote: > This helper script can be used to move symbols to libc.abilist across > all architectures, while preserving their symbol version. LGTM, thanks. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> > > --- > scripts/move-symbol-to-libc.py | 217 +++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 217 insertions(+) > > diff --git a/scripts/move-symbol-to-libc.py b/scripts/move-symbol-to-libc.py > new file mode 100644 > index 0000000000..4863c4dd8a > --- /dev/null > +++ b/scripts/move-symbol-to-libc.py > @@ -0,0 +1,217 @@ > +#!/usr/bin/python3 > +# Move symbols from other shared objects into libc.so. > +# Copyright (C) 2020 Free Software Foundation, Inc. > +# This file is part of the GNU C Library. > +# > +# The GNU C Library is free software; you can redistribute it and/or > +# modify it under the terms of the GNU Lesser General Public > +# License as published by the Free Software Foundation; either > +# version 2.1 of the License, or (at your option) any later version. > +# > +# The GNU C Library is distributed in the hope that it will be useful, > +# but WITHOUT ANY WARRANTY; without even the implied warranty of > +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > +# Lesser General Public License for more details. > +# > +# You should have received a copy of the GNU Lesser General Public > +# License along with the GNU C Library; if not, see > +# <https://www.gnu.org/licenses/>. > + > +"""Move symbols from other shared objects into libc.so. > + > +This script moves ABI symbols from non-libc abilists in to > +libc.abilist. Symbol versions are preserved. The script must be > +called from the top of the glibc source tree. > + > +""" > + > +import argparse > +import os.path > +import sys > + > +def replace_file(path, new_contents): > + """Atomically replace PATH with lines from NEW_CONTENTS. > + > + NEW_CONTENTS must be a sequence of strings. > + > + """ > + temppath = path + 'T' > + with open(temppath, 'w') as out: > + for line in new_contents: > + out.write(line) > + os.rename(temppath, path) > + > +class VersionedSymbol: > + """A combination of a symbol and its version.""" > + > + def __init__(self, symbol, version): > + """Construct a new versioned symbol.""" > + assert symbol > + assert version > + self.symbol = symbol > + self.version = version > + > + def __str__(self): > + return self.symbol + '@' + self.version > + > + def __eq__(self, other): > + return self.symbol == other.symbol and self.version == other.version > + > + def __hash__(self): > + return hash(self.symbol) ^ hash(self.version) Ok. > + > +def read_abilist(path): > + """Read the abilist file at PATH. > + > + Return a dictionary from VersionedSymbols to their flags (as > + strings). > + > + """ > + result = {} > + with open(path) as inp: > + for line in inp: > + version, symbol, flags = line.strip().split(' ', 2) > + result[VersionedSymbol(symbol, version)] = flags > + return result Ok. > + > +def abilist_lines(symbols): > + """Build the abilist file contents (as a list of lines). > + > + SYMBOLS is a dictionary from VersionedSymbols to their flags. > + > + """ > + result = [] > + for versym, flags in symbols.items(): > + result.append('{} {} {}\n'.format( > + versym.version, versym.symbol, flags)) > + result.sort() > + return result > + > +def add_to_libc_path(path, new_symbols): > + """Add SYMBOLS to the abilist file PATH. > + > + NEW_SYMBOLS is a dictionary from VersionedSymbols to their flags. > + > + """ > + original_symbols = read_abilist(path) > + updated_symbols = original_symbols.copy() > + updated_symbols.update(new_symbols) > + if updated_symbols != original_symbols: > + sys.stdout.write('updating libc abilist {}\n'.format(path)) > + replace_file(path, abilist_lines(updated_symbols)) Ok. > + > +# The name of the libc.so abilist file. > +libc_abilist = 'libc.abilist' > + > +def add_to_libc_fallback(directory, subdirs, symbol_lines): > + """Add SYMBOL_LINES to the libc.abilist files in SUBDIRS in DIRECTORY. > + > + All subdirectories must exist. If they do, return True. If not, > + skip processing and return False. > + > + """ > + abilists = [os.path.join(directory, subdir, libc_abilist) > + for subdir in subdirs] > + for abilist in abilists: > + if not os.path.exists(abilist): > + return False > + for abilist in abilists: > + add_to_libc_path(abilist, symbol_lines) > + return True Ok. > + > +def add_to_libc(directory, symbol_lines): > + > + """Add SYMBOL_LINES (a list of strings) to libc.abilist in DIRECTORY. > + > + Try specific subdirectories as well if libc.abilist is not found > + in DIRECTORY. > + > + """ > + libc_path = os.path.join(directory, libc_abilist) > + if os.path.exists(libc_path): > + add_to_libc_path(libc_path, symbol_lines) > + return > + > + # Special case for powerpc32 and mips32 variants. > + if add_to_libc_fallback(directory, ('fpu', 'nofpu'), symbol_lines): > + return > + > + # Special case for mips64. > + if add_to_libc_fallback(directory, ('n32', 'n64'), symbol_lines): > + return > + > + raise IOError('No libc.abilist found for: {}'.format(directory)) Ok. > + > +def move_symbols_1(path, to_move, moved_symbols): > + """Move SYMBOLS from the abilist file PATH to MOVED_SYMBOLS. > + > + TO_MOVE must be a set of strings. MOVED_SYMBOLS is a dictionary. > + > + """ > + suffix = '.abilist' > + assert path.endswith('.abilist') > + library = os.path.basename(path)[:-len(suffix)] > + placeholder = '__{}_version_placeholder'.format(library) > + > + new_lines = [] > + changed = False > + > + old_symbols = read_abilist(path) > + old_versions = set(versym.version for versym in old_symbols.keys()) > + matching_symbols = dict(e for e in old_symbols.items() > + if e[0].symbol in to_move) > + if matching_symbols: > + sys.stdout.write('updating {} abilist {}\n'.format(library, path)) > + new_symbols = dict(e for e in old_symbols.items() > + if e[0].symbol not in to_move) > + > + # Add placeholder symbols to prevent symbol versions from > + # going away completely. > + new_versions = set(versym.version for versym in new_symbols.keys()) > + for missing_version in old_versions - new_versions: > + new_symbols[VersionedSymbol(placeholder, missing_version)] = 'F' > + > + replace_file(path, abilist_lines(new_symbols)) > + > + moved_symbols.update(matching_symbols) Ok. > + > +def move_symbols(directory, files, symbols): > + """Move SYMBOLS from FILES (a list of abilist file names) in DIRECTORY. > + > + SYMBOLS must be a set of strings. > + > + """ > + moved_symbols = {} > + for filename in files: > + move_symbols_1(os.path.join(directory, filename), symbols, > + moved_symbols) > + if moved_symbols: > + add_to_libc(directory, moved_symbols) Ok. > + > +def get_parser(): > + """Return an argument parser for this module.""" > + parser = argparse.ArgumentParser(description=__doc__) > + parser.add_argument('--only-linux', action='store_true', > + help='Restrict the operation to Linux abilists') > + parser.add_argument('symbols', help='name of the symbol to move', > + nargs='+') > + return parser > + > +def main(argv): > + """The main entry point.""" > + parser = get_parser() > + opts = parser.parse_args(argv) > + if opts.only_linux: > + sysdeps = 'sysdeps/unix/sysv/linux' > + else: > + sysdeps = 'sysdeps' > + > + symbols = frozenset(opts.symbols) > + > + for directory, dirs, files in os.walk(sysdeps): > + move_symbols(directory, [name for name in files > + if name != 'libc.abilist' > + and name.endswith('.abilist')], symbols) > + > +if __name__ == '__main__': > + main(sys.argv[1:]) > Ok.
diff --git a/scripts/move-symbol-to-libc.py b/scripts/move-symbol-to-libc.py new file mode 100644 index 0000000000..4863c4dd8a --- /dev/null +++ b/scripts/move-symbol-to-libc.py @@ -0,0 +1,217 @@ +#!/usr/bin/python3 +# Move symbols from other shared objects into libc.so. +# Copyright (C) 2020 Free Software Foundation, Inc. +# This file is part of the GNU C Library. +# +# The GNU C Library is free software; you can redistribute it and/or +# modify it under the terms of the GNU Lesser General Public +# License as published by the Free Software Foundation; either +# version 2.1 of the License, or (at your option) any later version. +# +# The GNU C Library is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +# Lesser General Public License for more details. +# +# You should have received a copy of the GNU Lesser General Public +# License along with the GNU C Library; if not, see +# <https://www.gnu.org/licenses/>. + +"""Move symbols from other shared objects into libc.so. + +This script moves ABI symbols from non-libc abilists in to +libc.abilist. Symbol versions are preserved. The script must be +called from the top of the glibc source tree. + +""" + +import argparse +import os.path +import sys + +def replace_file(path, new_contents): + """Atomically replace PATH with lines from NEW_CONTENTS. + + NEW_CONTENTS must be a sequence of strings. + + """ + temppath = path + 'T' + with open(temppath, 'w') as out: + for line in new_contents: + out.write(line) + os.rename(temppath, path) + +class VersionedSymbol: + """A combination of a symbol and its version.""" + + def __init__(self, symbol, version): + """Construct a new versioned symbol.""" + assert symbol + assert version + self.symbol = symbol + self.version = version + + def __str__(self): + return self.symbol + '@' + self.version + + def __eq__(self, other): + return self.symbol == other.symbol and self.version == other.version + + def __hash__(self): + return hash(self.symbol) ^ hash(self.version) + +def read_abilist(path): + """Read the abilist file at PATH. + + Return a dictionary from VersionedSymbols to their flags (as + strings). + + """ + result = {} + with open(path) as inp: + for line in inp: + version, symbol, flags = line.strip().split(' ', 2) + result[VersionedSymbol(symbol, version)] = flags + return result + +def abilist_lines(symbols): + """Build the abilist file contents (as a list of lines). + + SYMBOLS is a dictionary from VersionedSymbols to their flags. + + """ + result = [] + for versym, flags in symbols.items(): + result.append('{} {} {}\n'.format( + versym.version, versym.symbol, flags)) + result.sort() + return result + +def add_to_libc_path(path, new_symbols): + """Add SYMBOLS to the abilist file PATH. + + NEW_SYMBOLS is a dictionary from VersionedSymbols to their flags. + + """ + original_symbols = read_abilist(path) + updated_symbols = original_symbols.copy() + updated_symbols.update(new_symbols) + if updated_symbols != original_symbols: + sys.stdout.write('updating libc abilist {}\n'.format(path)) + replace_file(path, abilist_lines(updated_symbols)) + +# The name of the libc.so abilist file. +libc_abilist = 'libc.abilist' + +def add_to_libc_fallback(directory, subdirs, symbol_lines): + """Add SYMBOL_LINES to the libc.abilist files in SUBDIRS in DIRECTORY. + + All subdirectories must exist. If they do, return True. If not, + skip processing and return False. + + """ + abilists = [os.path.join(directory, subdir, libc_abilist) + for subdir in subdirs] + for abilist in abilists: + if not os.path.exists(abilist): + return False + for abilist in abilists: + add_to_libc_path(abilist, symbol_lines) + return True + +def add_to_libc(directory, symbol_lines): + + """Add SYMBOL_LINES (a list of strings) to libc.abilist in DIRECTORY. + + Try specific subdirectories as well if libc.abilist is not found + in DIRECTORY. + + """ + libc_path = os.path.join(directory, libc_abilist) + if os.path.exists(libc_path): + add_to_libc_path(libc_path, symbol_lines) + return + + # Special case for powerpc32 and mips32 variants. + if add_to_libc_fallback(directory, ('fpu', 'nofpu'), symbol_lines): + return + + # Special case for mips64. + if add_to_libc_fallback(directory, ('n32', 'n64'), symbol_lines): + return + + raise IOError('No libc.abilist found for: {}'.format(directory)) + +def move_symbols_1(path, to_move, moved_symbols): + """Move SYMBOLS from the abilist file PATH to MOVED_SYMBOLS. + + TO_MOVE must be a set of strings. MOVED_SYMBOLS is a dictionary. + + """ + suffix = '.abilist' + assert path.endswith('.abilist') + library = os.path.basename(path)[:-len(suffix)] + placeholder = '__{}_version_placeholder'.format(library) + + new_lines = [] + changed = False + + old_symbols = read_abilist(path) + old_versions = set(versym.version for versym in old_symbols.keys()) + matching_symbols = dict(e for e in old_symbols.items() + if e[0].symbol in to_move) + if matching_symbols: + sys.stdout.write('updating {} abilist {}\n'.format(library, path)) + new_symbols = dict(e for e in old_symbols.items() + if e[0].symbol not in to_move) + + # Add placeholder symbols to prevent symbol versions from + # going away completely. + new_versions = set(versym.version for versym in new_symbols.keys()) + for missing_version in old_versions - new_versions: + new_symbols[VersionedSymbol(placeholder, missing_version)] = 'F' + + replace_file(path, abilist_lines(new_symbols)) + + moved_symbols.update(matching_symbols) + +def move_symbols(directory, files, symbols): + """Move SYMBOLS from FILES (a list of abilist file names) in DIRECTORY. + + SYMBOLS must be a set of strings. + + """ + moved_symbols = {} + for filename in files: + move_symbols_1(os.path.join(directory, filename), symbols, + moved_symbols) + if moved_symbols: + add_to_libc(directory, moved_symbols) + +def get_parser(): + """Return an argument parser for this module.""" + parser = argparse.ArgumentParser(description=__doc__) + parser.add_argument('--only-linux', action='store_true', + help='Restrict the operation to Linux abilists') + parser.add_argument('symbols', help='name of the symbol to move', + nargs='+') + return parser + +def main(argv): + """The main entry point.""" + parser = get_parser() + opts = parser.parse_args(argv) + if opts.only_linux: + sysdeps = 'sysdeps/unix/sysv/linux' + else: + sysdeps = 'sysdeps' + + symbols = frozenset(opts.symbols) + + for directory, dirs, files in os.walk(sysdeps): + move_symbols(directory, [name for name in files + if name != 'libc.abilist' + and name.endswith('.abilist')], symbols) + +if __name__ == '__main__': + main(sys.argv[1:])