Add scripts/move-symbol-to-libc.py
Commit Message
This helper script can be used to move symbols to libc.abilist across
all architectures, while preserving their symbol version.
---
scripts/move-symbol-to-libc.py | 157 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 157 insertions(+)
Comments
* Florian Weimer:
> This helper script can be used to move symbols to libc.abilist across
> all architectures, while preserving their symbol version.
I have an update for this, which I will post later. It also takes care
of empty symbol versions.
Thanks,
Florian
new file mode 100644
@@ -0,0 +1,157 @@
+#!/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)
+
+def add_to_libc_path(path, symbol_lines):
+ """Add SYMBOL_LINES (a list of strings) to the abilist file PATH."""
+ with open(path) as inp:
+ original_lines = list(inp)
+ new_lines = set(original_lines)
+ new_lines.update(symbol_lines)
+ new_lines = list(new_lines)
+ new_lines.sort()
+ if new_lines != original_lines:
+ sys.stdout.write('updating libc abilist {!r}\n'.format(path))
+ replace_file(path, new_lines)
+
+# 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: {!r}'.format(directory))
+
+def move_symbols_1(path, symbols, moved_symbols):
+ """Move SYMBOLS from the abilist file PATH to MOVED_SYMBOLS.
+
+ SYMBOLS must be a set of strings. MOVED_SYMBOLS is a list.
+
+ """
+ new_lines = []
+ changed = False
+ with open(path) as inp:
+ for line in inp:
+ version, symbol, flags = line.split(' ', 2)
+ if symbol in symbols:
+ moved_symbols.append(line)
+ changed = True
+ else:
+ new_lines.append(line)
+ if changed:
+ sys.stdout.write('updating source abilist {!r}\n'.format(path))
+ replace_file(path, new_lines)
+
+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:])