#!/usr/bin/env python
# Script checking that all symbols exported by libpython start with Py or _Py
import os.path
import subprocess
import sys
import sysconfig
ALLOWED_PREFIXES = ('Py', '_Py')
if sys.platform == 'darwin':
ALLOWED_PREFIXES += ('__Py',)
# mimalloc doesn't use static, but it's symbols are not exported
# from the shared library. They do show up in the static library
# before its linked into an executable.
ALLOWED_STATIC_PREFIXES = ('mi_', '_mi_')
# "Legacy": some old symbols are prefixed by "PY_".
EXCEPTIONS = frozenset({
'PY_TIMEOUT_MAX',
})
IGNORED_EXTENSION = "_ctypes_test"
# Ignore constructor and destructor functions
IGNORED_SYMBOLS = {'_init', '_fini'}
def is_local_symbol_type(symtype):
# Ignore local symbols.
# If lowercase, the symbol is usually local; if uppercase, the symbol
# is global (external). There are however a few lowercase symbols that
# are shown for special global symbols ("u", "v" and "w").
if symtype.islower() and symtype not in "uvw":
return True
# Ignore the initialized data section (d and D) and the BSS data
# section. For example, ignore "__bss_start (type: B)"
# and "_edata (type: D)".
if symtype in "bBdD":
return True
return False
def get_exported_symbols(library, dynamic=False):
print(f"Check that {library} only exports symbols starting with Py or _Py")
# Only look at dynamic symbols
args = ['nm', '--no-sort']
if dynamic:
args.append('--dynamic')
args.append(library)
print("+ %s" % ' '.join(args))
proc = subprocess.run(args, stdout=subprocess.PIPE, universal_newlines=True)
if proc.returncode:
sys.stdout.write(proc.stdout)
sys.exit(proc.returncode)
stdout = proc.stdout.rstrip()
if not stdout:
raise Exception("command output is empty")
return stdout
def get_smelly_symbols(stdout, dynamic=False):
smelly_symbols = []
python_symbols = []
local_symbols = []
for line in stdout.splitlines():
# Split line '0000000000001b80 D PyTextIOWrapper_Type'
if not line:
continue
parts = line.split(maxsplit=2)
if len(parts) < 3:
continue
symtype = parts[1].strip()
symbol = parts[-1]
result = '%s (type: %s)' % (symbol, symtype)
if (symbol.startswith(ALLOWED_PREFIXES) or
symbol in EXCEPTIONS or
(not dynamic and symbol.startswith(ALLOWED_STATIC_PREFIXES))):
python_symbols.append(result)
continue
if is_local_symbol_type(symtype):
local_symbols.append(result)
elif symbol in IGNORED_SYMBOLS:
local_symbols.append(result)
else:
smelly_symbols.append(result)
if local_symbols:
print(f"Ignore {len(local_symbols)} local symbols")
return smelly_symbols, python_symbols
def check_library(library, dynamic=False):
nm_output = get_exported_symbols(library, dynamic)
smelly_symbols, python_symbols = get_smelly_symbols(nm_output, dynamic)
if not smelly_symbols:
print(f"OK: no smelly symbol found ({len(python_symbols)} Python symbols)")
return 0
print()
smelly_symbols.sort()
for symbol in smelly_symbols:
print("Smelly symbol: %s" % symbol)
print()
print("ERROR: Found %s smelly symbols!" % len(smelly_symbols))
return len(smelly_symbols)
def check_extensions():
print(__file__)
# This assumes pybuilddir.txt is in same directory as pyconfig.h.
# In the case of out-of-tree builds, we can't assume pybuilddir.txt is
# in the source folder.
config_dir = os.path.dirname(sysconfig.get_config_h_filename())
filename = os.path.join(config_dir, "pybuilddir.txt")
try:
with open(filename, encoding="utf-8") as fp:
pybuilddir = fp.readline()
except FileNotFoundError:
print(f"Cannot check extensions because {filename} does not exist")
return True
print(f"Check extension modules from {pybuilddir} directory")
builddir = os.path.join(config_dir, pybuilddir)
nsymbol = 0
for name in os.listdir(builddir):
if not name.endswith(".so"):
continue
if IGNORED_EXTENSION in name:
print()
print(f"Ignore extension: {name}")
continue
print()
filename = os.path.join(builddir, name)
nsymbol += check_library(filename, dynamic=True)
return nsymbol
def main():
nsymbol = 0
# static library
LIBRARY = sysconfig.get_config_var('LIBRARY')
if not LIBRARY:
raise Exception("failed to get LIBRARY variable from sysconfig")
if os.path.exists(LIBRARY):
nsymbol += check_library(LIBRARY)
# dynamic library
LDLIBRARY = sysconfig.get_config_var('LDLIBRARY')
if not LDLIBRARY:
raise Exception("failed to get LDLIBRARY variable from sysconfig")
if LDLIBRARY != LIBRARY:
print()
nsymbol += check_library(LDLIBRARY, dynamic=True)
# Check extension modules like _ssl.cpython-310d-x86_64-linux-gnu.so
nsymbol += check_extensions()
if nsymbol:
print()
print(f"ERROR: Found {nsymbol} smelly symbols in total!")
sys.exit(1)
print()
print(f"OK: all exported symbols of all libraries "
f"are prefixed with {' or '.join(map(repr, ALLOWED_PREFIXES))}")
if __name__ == "__main__":
main()
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