blob: e1ca0b78886d05504d2795f3b1d509b54c6cf83a [file] [log] [blame]
#!/usr/bin/env python
# Copyright (c) 2017 Google Inc.
# 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.
"""Ensures that all externally visible functions in the library have an appropriate name
Appropriate function names are:
- names starting with spv,
- anything in a namespace,
- functions added by the protobuf compiler,
- and weak definitions of new and delete."""
import os.path
import re
import subprocess
import sys
PROG = 'check_symbol_exports'
def command_output(cmd, directory):
"""Runs a command in a directory and returns its standard output stream.
Captures the standard error stream.
Raises a RuntimeError if the command fails to launch or otherwise fails.
"""
p = subprocess.Popen(cmd,
cwd=directory,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE,
universal_newlines=True)
(stdout, _) = p.communicate()
if p.returncode != 0:
raise RuntimeError('Failed to run %s in %s' % (cmd, directory))
return stdout
def check_library(library):
"""Scans the given library file for global exports. If all such
exports are namespaced or begin with spv (in either C or C++ styles)
then return 0. Otherwise emit a message and return 1."""
# The pattern for an externally visible symbol record
symbol_pattern = re.compile(r'^[0-aA-Fa-f]+ +([wg]) *F \.text.*[0-9A-Fa-f]+ +(.*)')
# Ok patterns are as follows, assuming Itanium name mangling:
# spv[A-Z] : extern "C" symbol starting with spv
# _ZN : something in a namespace
# _ZSt : something in the standard namespace
# _ZZN : something in a local scope and namespace
# _Z[0-9]+spv[A-Z_] : C++ symbol starting with spv[A-Z_]
symbol_ok_pattern = re.compile(r'^(spv[A-Z]|_ZN|_ZSt|_ZZN|_Z[0-9]+spv[A-Z_])')
# In addition, the following pattern allowlists global functions that are added
# by the protobuf compiler:
# - AddDescriptors_spvtoolsfuzz_2eproto()
# - InitDefaults_spvtoolsfuzz_2eproto()
symbol_allowlist_pattern = re.compile(r'_Z[0-9]+.*spvtoolsfuzz_2eproto.*')
symbol_is_new_or_delete = re.compile(r'^(_Zna|_Znw|_Zdl|_Zda)')
# Compilaion for Arm has various thunks for constructors, destructors, vtables.
# They are weak.
symbol_is_thunk = re.compile(r'^_ZT')
# This occurs in NDK builds.
symbol_is_hidden = re.compile(r'^\.hidden ')
seen = set()
result = 0
for line in command_output(['objdump', '-t', library], '.').split('\n'):
match = symbol_pattern.search(line)
if match:
linkage = match.group(1)
symbol = match.group(2)
if symbol not in seen:
seen.add(symbol)
#print("look at '{}'".format(symbol))
if not (symbol_is_new_or_delete.match(symbol) and linkage == 'w'):
if not (symbol_is_thunk.match(symbol) and linkage == 'w'):
if not (symbol_allowlist_pattern.match(symbol) or
symbol_ok_pattern.match(symbol) or
symbol_is_hidden.match(symbol)):
print('{}: error: Unescaped exported symbol: {}'.format(PROG, symbol))
result = 1
return result
def main():
import argparse
parser = argparse.ArgumentParser(description='Check global names exported from a library')
parser.add_argument('library', help='The static library to examine')
args = parser.parse_args()
if not os.path.isfile(args.library):
print('{}: error: {} does not exist'.format(PROG, args.library))
sys.exit(1)
if os.name == 'posix':
status = check_library(args.library)
sys.exit(status)
else:
print('Passing test since not on Posix')
sys.exit(0)
if __name__ == '__main__':
main()