diff --git a/Lib/ctypes/test/test_find.py b/Lib/ctypes/test/test_find.py index bfb6b42cbb2..4a8a3820f3f 100644 --- a/Lib/ctypes/test/test_find.py +++ b/Lib/ctypes/test/test_find.py @@ -1,4 +1,5 @@ import unittest +import unittest.mock import os.path import sys import test.support @@ -73,7 +74,7 @@ class Test_OpenGL_libs(unittest.TestCase): @unittest.skipUnless(sys.platform.startswith('linux'), 'Test only valid for Linux') -class LibPathFindTest(unittest.TestCase): +class FindLibraryLinux(unittest.TestCase): def test_find_on_libpath(self): import subprocess import tempfile @@ -112,6 +113,15 @@ class LibPathFindTest(unittest.TestCase): # LD_LIBRARY_PATH) self.assertEqual(find_library(libname), 'lib%s.so' % libname) + def test_find_library_with_gcc(self): + with unittest.mock.patch("ctypes.util._findSoname_ldconfig", lambda *args: None): + self.assertNotEqual(find_library('c'), None) + + def test_find_library_with_ld(self): + with unittest.mock.patch("ctypes.util._findSoname_ldconfig", lambda *args: None), \ + unittest.mock.patch("ctypes.util._findLib_gcc", lambda *args: None): + self.assertNotEqual(find_library('c'), None) + if __name__ == "__main__": unittest.main() diff --git a/Lib/ctypes/util.py b/Lib/ctypes/util.py index 01176bf9696..0c2510e1619 100644 --- a/Lib/ctypes/util.py +++ b/Lib/ctypes/util.py @@ -93,6 +93,12 @@ elif os.name == "posix": # Andreas Degert's find functions, using gcc, /sbin/ldconfig, objdump import re, tempfile + def _is_elf(filename): + "Return True if the given file is an ELF file" + elf_header = b'\x7fELF' + with open(filename, 'br') as thefile: + return thefile.read(4) == elf_header + def _findLib_gcc(name): # Run GCC's linker with the -t (aka --trace) option and examine the # library name it prints out. The GCC command will fail because we @@ -130,10 +136,17 @@ elif os.name == "posix": # Raised if the file was already removed, which is the normal # behaviour of GCC if linking fails pass - res = re.search(expr, trace) + res = re.findall(expr, trace) if not res: return None - return os.fsdecode(res.group(0)) + + for file in res: + # Check if the given file is an elf file: gcc can report + # some files that are linker scripts and not actual + # shared objects. See bpo-41976 for more details + if not _is_elf(file): + continue + return os.fsdecode(file) if sys.platform == "sunos5": @@ -299,9 +312,14 @@ elif os.name == "posix": stderr=subprocess.PIPE, universal_newlines=True) out, _ = p.communicate() - res = re.search(expr, os.fsdecode(out)) - if res: - result = res.group(0) + res = re.findall(expr, os.fsdecode(out)) + for file in res: + # Check if the given file is an elf file: gcc can report + # some files that are linker scripts and not actual + # shared objects. See bpo-41976 for more details + if not _is_elf(file): + continue + return os.fsdecode(file) except Exception: pass # result will be None return result @@ -309,7 +327,7 @@ elif os.name == "posix": def find_library(name): # See issue #9998 return _findSoname_ldconfig(name) or \ - _get_soname(_findLib_gcc(name) or _findLib_ld(name)) + _get_soname(_findLib_gcc(name)) or _get_soname(_findLib_ld(name)) ################################################################ # test code diff --git a/Misc/NEWS.d/next/Library/2020-10-08-18-22-28.bpo-41976.Svm0wb.rst b/Misc/NEWS.d/next/Library/2020-10-08-18-22-28.bpo-41976.Svm0wb.rst new file mode 100644 index 00000000000..c8b3fc77184 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2020-10-08-18-22-28.bpo-41976.Svm0wb.rst @@ -0,0 +1,3 @@ +Fixed a bug that was causing :func:`ctypes.util.find_library` to return +``None`` when triying to locate a library in an environment when gcc>=9 is +available and ``ldconfig`` is not. Patch by Pablo Galindo