neobytes/contrib/devtools/symbol-check.py
Wladimir J. van der Laan 202c95c216 devtools: have symbol check script check for exported symbols
After last commit, our executables should export no symbols anymore.  To
make sure that this stays the case, verify this in the symbol checker
script.
2014-04-30 15:30:39 +02:00

114 lines
4.1 KiB
Python
Executable File

#!/usr/bin/python
# Copyright (c) 2014 Wladimir J. van der Laan
# Distributed under the MIT/X11 software license, see the accompanying
# file COPYING or http://www.opensource.org/licenses/mit-license.php.
'''
A script to check that the (Linux) executables produced by gitian only contain
allowed gcc, glibc and libstdc++ version symbols. This makes sure they are
still compatible with the minimum supported Linux distribution versions.
Example usage:
find ../gitian-builder/build -type f -executable | xargs python contrib/devtools/symbol-check.py
'''
from __future__ import division, print_function
import subprocess
import re
import sys
# Debian 6.0.9 (Squeeze) has:
#
# - g++ version 4.4.5 (https://packages.debian.org/search?suite=default&section=all&arch=any&searchon=names&keywords=g%2B%2B)
# - libc version 2.11.3 (https://packages.debian.org/search?suite=default&section=all&arch=any&searchon=names&keywords=libc6)
# - libstdc++ version 4.4.5 (https://packages.debian.org/search?suite=default&section=all&arch=any&searchon=names&keywords=libstdc%2B%2B6)
#
# Ubuntu 10.04.4 (Lucid Lynx) has:
#
# - g++ version 4.4.3 (http://packages.ubuntu.com/search?keywords=g%2B%2B&searchon=names&suite=lucid&section=all)
# - libc version 2.11.1 (http://packages.ubuntu.com/search?keywords=libc6&searchon=names&suite=lucid&section=all)
# - libstdc++ version 4.4.3 (http://packages.ubuntu.com/search?suite=lucid&section=all&arch=any&keywords=libstdc%2B%2B&searchon=names)
#
# Taking the minimum of these as our target.
#
# According to GNU ABI document (http://gcc.gnu.org/onlinedocs/libstdc++/manual/abi.html) this corresponds to:
# GCC 4.4.0: GCC_4.4.0
# GCC 4.4.2: GLIBCXX_3.4.13, CXXABI_1.3.3
# (glibc) GLIBC_2_11
#
MAX_VERSIONS = {
'GCC': (4,4,0),
'CXXABI': (1,3,3),
'GLIBCXX': (3,4,13),
'GLIBC': (2,11)
}
READELF_CMD = '/usr/bin/readelf'
CPPFILT_CMD = '/usr/bin/c++filt'
class CPPFilt(object):
'''
Demangle C++ symbol names.
Use a pipe to the 'c++filt' command.
'''
def __init__(self):
self.proc = subprocess.Popen(CPPFILT_CMD, stdin=subprocess.PIPE, stdout=subprocess.PIPE)
def __call__(self, mangled):
self.proc.stdin.write(mangled + '\n')
return self.proc.stdout.readline().rstrip()
def close(self):
self.proc.stdin.close()
self.proc.stdout.close()
self.proc.wait()
def read_symbols(executable, imports=True):
'''
Parse an ELF executable and return a list of (symbol,version) tuples
for dynamic, imported symbols.
'''
p = subprocess.Popen([READELF_CMD, '--dyn-syms', '-W', executable], stdout=subprocess.PIPE, stderr=subprocess.PIPE, stdin=subprocess.PIPE)
(stdout, stderr) = p.communicate()
if p.returncode:
raise IOError('Could not read symbols for %s: %s' % (executable, stderr.strip()))
syms = []
for line in stdout.split('\n'):
line = line.split()
if len(line)>7 and re.match('[0-9]+:$', line[0]):
(sym, _, version) = line[7].partition('@')
is_import = line[6] == 'UND'
if version.startswith('@'):
version = version[1:]
if is_import == imports:
syms.append((sym, version))
return syms
def check_version(max_versions, version):
if '_' in version:
(lib, _, ver) = version.rpartition('_')
else:
lib = version
ver = '0'
ver = tuple([int(x) for x in ver.split('.')])
if not lib in max_versions:
return False
return ver <= max_versions[lib]
if __name__ == '__main__':
cppfilt = CPPFilt()
retval = 0
for filename in sys.argv[1:]:
# Check imported symbols
for sym,version in read_symbols(filename, True):
if version and not check_version(MAX_VERSIONS, version):
print('%s: symbol %s from unsupported version %s' % (filename, cppfilt(sym), version))
retval = 1
# Check exported symbols
for sym,version in read_symbols(filename, False):
print('%s: export of symbol %s not allowed' % (filename, cppfilt(sym)))
retval = 1
exit(retval)