1# Verify that gdb can pretty-print the various PyObject* types 2# 3# The code for testing gdb was adapted from similar work in Unladen Swallow's 4# Lib/test/test_jit_gdb.py 5 6import os 7import platform 8import re 9import subprocess 10import sys 11import sysconfig 12import textwrap 13import unittest 14 15from test import support 16from test.support import findfile, python_is_optimized 17 18def get_gdb_version(): 19 try: 20 cmd = ["gdb", "-nx", "--version"] 21 proc = subprocess.Popen(cmd, 22 stdout=subprocess.PIPE, 23 stderr=subprocess.PIPE, 24 universal_newlines=True) 25 with proc: 26 version, stderr = proc.communicate() 27 28 if proc.returncode: 29 raise Exception(f"Command {' '.join(cmd)!r} failed " 30 f"with exit code {proc.returncode}: " 31 f"stdout={version!r} stderr={stderr!r}") 32 except OSError: 33 # This is what "no gdb" looks like. There may, however, be other 34 # errors that manifest this way too. 35 raise unittest.SkipTest("Couldn't find gdb on the path") 36 37 # Regex to parse: 38 # 'GNU gdb (GDB; SUSE Linux Enterprise 12) 7.7\n' -> 7.7 39 # 'GNU gdb (GDB) Fedora 7.9.1-17.fc22\n' -> 7.9 40 # 'GNU gdb 6.1.1 [FreeBSD]\n' -> 6.1 41 # 'GNU gdb (GDB) Fedora (7.5.1-37.fc18)\n' -> 7.5 42 # 'HP gdb 6.7 for HP Itanium (32 or 64 bit) and target HP-UX 11iv2 and 11iv3.\n' -> 6.7 43 match = re.search(r"^(?:GNU|HP) gdb.*?\b(\d+)\.(\d+)", version) 44 if match is None: 45 raise Exception("unable to parse GDB version: %r" % version) 46 return (version, int(match.group(1)), int(match.group(2))) 47 48gdb_version, gdb_major_version, gdb_minor_version = get_gdb_version() 49if gdb_major_version < 7: 50 raise unittest.SkipTest("gdb versions before 7.0 didn't support python " 51 "embedding. Saw %s.%s:\n%s" 52 % (gdb_major_version, gdb_minor_version, 53 gdb_version)) 54 55if not sysconfig.is_python_build(): 56 raise unittest.SkipTest("test_gdb only works on source builds at the moment.") 57 58if 'Clang' in platform.python_compiler() and sys.platform == 'darwin': 59 raise unittest.SkipTest("test_gdb doesn't work correctly when python is" 60 " built with LLVM clang") 61 62if ((sysconfig.get_config_var('PGO_PROF_USE_FLAG') or 'xxx') in 63 (sysconfig.get_config_var('PY_CORE_CFLAGS') or '')): 64 raise unittest.SkipTest("test_gdb is not reliable on PGO builds") 65 66# Location of custom hooks file in a repository checkout. 67checkout_hook_path = os.path.join(os.path.dirname(sys.executable), 68 'python-gdb.py') 69 70PYTHONHASHSEED = '123' 71 72 73def cet_protection(): 74 cflags = sysconfig.get_config_var('CFLAGS') 75 if not cflags: 76 return False 77 flags = cflags.split() 78 # True if "-mcet -fcf-protection" options are found, but false 79 # if "-fcf-protection=none" or "-fcf-protection=return" is found. 80 return (('-mcet' in flags) 81 and any((flag.startswith('-fcf-protection') 82 and not flag.endswith(("=none", "=return"))) 83 for flag in flags)) 84 85# Control-flow enforcement technology 86CET_PROTECTION = cet_protection() 87 88 89def run_gdb(*args, **env_vars): 90 """Runs gdb in --batch mode with the additional arguments given by *args. 91 92 Returns its (stdout, stderr) decoded from utf-8 using the replace handler. 93 """ 94 if env_vars: 95 env = os.environ.copy() 96 env.update(env_vars) 97 else: 98 env = None 99 # -nx: Do not execute commands from any .gdbinit initialization files 100 # (issue #22188) 101 base_cmd = ('gdb', '--batch', '-nx') 102 if (gdb_major_version, gdb_minor_version) >= (7, 4): 103 base_cmd += ('-iex', 'add-auto-load-safe-path ' + checkout_hook_path) 104 proc = subprocess.Popen(base_cmd + args, 105 # Redirect stdin to prevent GDB from messing with 106 # the terminal settings 107 stdin=subprocess.PIPE, 108 stdout=subprocess.PIPE, 109 stderr=subprocess.PIPE, 110 env=env) 111 with proc: 112 out, err = proc.communicate() 113 return out.decode('utf-8', 'replace'), err.decode('utf-8', 'replace') 114 115# Verify that "gdb" was built with the embedded python support enabled: 116gdbpy_version, _ = run_gdb("--eval-command=python import sys; print(sys.version_info)") 117if not gdbpy_version: 118 raise unittest.SkipTest("gdb not built with embedded python support") 119 120if "major=2" in gdbpy_version: 121 raise unittest.SkipTest("gdb built with Python 2") 122 123# Verify that "gdb" can load our custom hooks, as OS security settings may 124# disallow this without a customized .gdbinit. 125_, gdbpy_errors = run_gdb('--args', sys.executable) 126if "auto-loading has been declined" in gdbpy_errors: 127 msg = "gdb security settings prevent use of custom hooks: " 128 raise unittest.SkipTest(msg + gdbpy_errors.rstrip()) 129 130def gdb_has_frame_select(): 131 # Does this build of gdb have gdb.Frame.select ? 132 stdout, _ = run_gdb("--eval-command=python print(dir(gdb.Frame))") 133 m = re.match(r'.*\[(.*)\].*', stdout) 134 if not m: 135 raise unittest.SkipTest("Unable to parse output from gdb.Frame.select test") 136 gdb_frame_dir = m.group(1).split(', ') 137 return "'select'" in gdb_frame_dir 138 139HAS_PYUP_PYDOWN = gdb_has_frame_select() 140 141BREAKPOINT_FN='builtin_id' 142 143@unittest.skipIf(support.PGO, "not useful for PGO") 144class DebuggerTests(unittest.TestCase): 145 146 """Test that the debugger can debug Python.""" 147 148 def get_stack_trace(self, source=None, script=None, 149 breakpoint=BREAKPOINT_FN, 150 cmds_after_breakpoint=None, 151 import_site=False, 152 ignore_stderr=False): 153 ''' 154 Run 'python -c SOURCE' under gdb with a breakpoint. 155 156 Support injecting commands after the breakpoint is reached 157 158 Returns the stdout from gdb 159 160 cmds_after_breakpoint: if provided, a list of strings: gdb commands 161 ''' 162 # We use "set breakpoint pending yes" to avoid blocking with a: 163 # Function "foo" not defined. 164 # Make breakpoint pending on future shared library load? (y or [n]) 165 # error, which typically happens python is dynamically linked (the 166 # breakpoints of interest are to be found in the shared library) 167 # When this happens, we still get: 168 # Function "textiowrapper_write" not defined. 169 # emitted to stderr each time, alas. 170 171 # Initially I had "--eval-command=continue" here, but removed it to 172 # avoid repeated print breakpoints when traversing hierarchical data 173 # structures 174 175 # Generate a list of commands in gdb's language: 176 commands = ['set breakpoint pending yes', 177 'break %s' % breakpoint, 178 179 # The tests assume that the first frame of printed 180 # backtrace will not contain program counter, 181 # that is however not guaranteed by gdb 182 # therefore we need to use 'set print address off' to 183 # make sure the counter is not there. For example: 184 # #0 in PyObject_Print ... 185 # is assumed, but sometimes this can be e.g. 186 # #0 0x00003fffb7dd1798 in PyObject_Print ... 187 'set print address off', 188 189 'run'] 190 191 # GDB as of 7.4 onwards can distinguish between the 192 # value of a variable at entry vs current value: 193 # http://sourceware.org/gdb/onlinedocs/gdb/Variables.html 194 # which leads to the selftests failing with errors like this: 195 # AssertionError: 'v@entry=()' != '()' 196 # Disable this: 197 if (gdb_major_version, gdb_minor_version) >= (7, 4): 198 commands += ['set print entry-values no'] 199 200 if cmds_after_breakpoint: 201 if CET_PROTECTION: 202 # bpo-32962: When Python is compiled with -mcet 203 # -fcf-protection, function arguments are unusable before 204 # running the first instruction of the function entry point. 205 # The 'next' command makes the required first step. 206 commands += ['next'] 207 commands += cmds_after_breakpoint 208 else: 209 commands += ['backtrace'] 210 211 # print commands 212 213 # Use "commands" to generate the arguments with which to invoke "gdb": 214 args = ['--eval-command=%s' % cmd for cmd in commands] 215 args += ["--args", 216 sys.executable] 217 args.extend(subprocess._args_from_interpreter_flags()) 218 219 if not import_site: 220 # -S suppresses the default 'import site' 221 args += ["-S"] 222 223 if source: 224 args += ["-c", source] 225 elif script: 226 args += [script] 227 228 # Use "args" to invoke gdb, capturing stdout, stderr: 229 out, err = run_gdb(*args, PYTHONHASHSEED=PYTHONHASHSEED) 230 231 if not ignore_stderr: 232 for line in err.splitlines(): 233 print(line, file=sys.stderr) 234 235 # bpo-34007: Sometimes some versions of the shared libraries that 236 # are part of the traceback are compiled in optimised mode and the 237 # Program Counter (PC) is not present, not allowing gdb to walk the 238 # frames back. When this happens, the Python bindings of gdb raise 239 # an exception, making the test impossible to succeed. 240 if "PC not saved" in err: 241 raise unittest.SkipTest("gdb cannot walk the frame object" 242 " because the Program Counter is" 243 " not present") 244 245 # bpo-40019: Skip the test if gdb failed to read debug information 246 # because the Python binary is optimized. 247 for pattern in ( 248 '(frame information optimized out)', 249 'Unable to read information on python frame', 250 ): 251 if pattern in out: 252 raise unittest.SkipTest(f"{pattern!r} found in gdb output") 253 254 return out 255 256 def get_gdb_repr(self, source, 257 cmds_after_breakpoint=None, 258 import_site=False): 259 # Given an input python source representation of data, 260 # run "python -c'id(DATA)'" under gdb with a breakpoint on 261 # builtin_id and scrape out gdb's representation of the "op" 262 # parameter, and verify that the gdb displays the same string 263 # 264 # Verify that the gdb displays the expected string 265 # 266 # For a nested structure, the first time we hit the breakpoint will 267 # give us the top-level structure 268 269 # NOTE: avoid decoding too much of the traceback as some 270 # undecodable characters may lurk there in optimized mode 271 # (issue #19743). 272 cmds_after_breakpoint = cmds_after_breakpoint or ["backtrace 1"] 273 gdb_output = self.get_stack_trace(source, breakpoint=BREAKPOINT_FN, 274 cmds_after_breakpoint=cmds_after_breakpoint, 275 import_site=import_site) 276 # gdb can insert additional '\n' and space characters in various places 277 # in its output, depending on the width of the terminal it's connected 278 # to (using its "wrap_here" function) 279 m = re.search( 280 # Match '#0 builtin_id(self=..., v=...)' 281 r'#0\s+builtin_id\s+\(self\=.*,\s+v=\s*(.*?)?\)' 282 # Match ' at Python/bltinmodule.c'. 283 # bpo-38239: builtin_id() is defined in Python/bltinmodule.c, 284 # but accept any "Directory\file.c" to support Link Time 285 # Optimization (LTO). 286 r'\s+at\s+\S*[A-Za-z]+/[A-Za-z0-9_-]+\.c', 287 gdb_output, re.DOTALL) 288 if not m: 289 self.fail('Unexpected gdb output: %r\n%s' % (gdb_output, gdb_output)) 290 return m.group(1), gdb_output 291 292 def assertEndsWith(self, actual, exp_end): 293 '''Ensure that the given "actual" string ends with "exp_end"''' 294 self.assertTrue(actual.endswith(exp_end), 295 msg='%r did not end with %r' % (actual, exp_end)) 296 297 def assertMultilineMatches(self, actual, pattern): 298 m = re.match(pattern, actual, re.DOTALL) 299 if not m: 300 self.fail(msg='%r did not match %r' % (actual, pattern)) 301 302 def get_sample_script(self): 303 return findfile('gdb_sample.py') 304 305class PrettyPrintTests(DebuggerTests): 306 def test_getting_backtrace(self): 307 gdb_output = self.get_stack_trace('id(42)') 308 self.assertTrue(BREAKPOINT_FN in gdb_output) 309 310 def assertGdbRepr(self, val, exp_repr=None): 311 # Ensure that gdb's rendering of the value in a debugged process 312 # matches repr(value) in this process: 313 gdb_repr, gdb_output = self.get_gdb_repr('id(' + ascii(val) + ')') 314 if not exp_repr: 315 exp_repr = repr(val) 316 self.assertEqual(gdb_repr, exp_repr, 317 ('%r did not equal expected %r; full output was:\n%s' 318 % (gdb_repr, exp_repr, gdb_output))) 319 320 def test_int(self): 321 'Verify the pretty-printing of various int values' 322 self.assertGdbRepr(42) 323 self.assertGdbRepr(0) 324 self.assertGdbRepr(-7) 325 self.assertGdbRepr(1000000000000) 326 self.assertGdbRepr(-1000000000000000) 327 328 def test_singletons(self): 329 'Verify the pretty-printing of True, False and None' 330 self.assertGdbRepr(True) 331 self.assertGdbRepr(False) 332 self.assertGdbRepr(None) 333 334 def test_dicts(self): 335 'Verify the pretty-printing of dictionaries' 336 self.assertGdbRepr({}) 337 self.assertGdbRepr({'foo': 'bar'}, "{'foo': 'bar'}") 338 # Python preserves insertion order since 3.6 339 self.assertGdbRepr({'foo': 'bar', 'douglas': 42}, "{'foo': 'bar', 'douglas': 42}") 340 341 def test_lists(self): 342 'Verify the pretty-printing of lists' 343 self.assertGdbRepr([]) 344 self.assertGdbRepr(list(range(5))) 345 346 def test_bytes(self): 347 'Verify the pretty-printing of bytes' 348 self.assertGdbRepr(b'') 349 self.assertGdbRepr(b'And now for something hopefully the same') 350 self.assertGdbRepr(b'string with embedded NUL here \0 and then some more text') 351 self.assertGdbRepr(b'this is a tab:\t' 352 b' this is a slash-N:\n' 353 b' this is a slash-R:\r' 354 ) 355 356 self.assertGdbRepr(b'this is byte 255:\xff and byte 128:\x80') 357 358 self.assertGdbRepr(bytes([b for b in range(255)])) 359 360 def test_strings(self): 361 'Verify the pretty-printing of unicode strings' 362 # We cannot simply call locale.getpreferredencoding() here, 363 # as GDB might have been linked against a different version 364 # of Python with a different encoding and coercion policy 365 # with respect to PEP 538 and PEP 540. 366 out, err = run_gdb( 367 '--eval-command', 368 'python import locale; print(locale.getpreferredencoding())') 369 370 encoding = out.rstrip() 371 if err or not encoding: 372 raise RuntimeError( 373 f'unable to determine the preferred encoding ' 374 f'of embedded Python in GDB: {err}') 375 376 def check_repr(text): 377 try: 378 text.encode(encoding) 379 except UnicodeEncodeError: 380 self.assertGdbRepr(text, ascii(text)) 381 else: 382 self.assertGdbRepr(text) 383 384 self.assertGdbRepr('') 385 self.assertGdbRepr('And now for something hopefully the same') 386 self.assertGdbRepr('string with embedded NUL here \0 and then some more text') 387 388 # Test printing a single character: 389 # U+2620 SKULL AND CROSSBONES 390 check_repr('\u2620') 391 392 # Test printing a Japanese unicode string 393 # (I believe this reads "mojibake", using 3 characters from the CJK 394 # Unified Ideographs area, followed by U+3051 HIRAGANA LETTER KE) 395 check_repr('\u6587\u5b57\u5316\u3051') 396 397 # Test a character outside the BMP: 398 # U+1D121 MUSICAL SYMBOL C CLEF 399 # This is: 400 # UTF-8: 0xF0 0x9D 0x84 0xA1 401 # UTF-16: 0xD834 0xDD21 402 check_repr(chr(0x1D121)) 403 404 def test_tuples(self): 405 'Verify the pretty-printing of tuples' 406 self.assertGdbRepr(tuple(), '()') 407 self.assertGdbRepr((1,), '(1,)') 408 self.assertGdbRepr(('foo', 'bar', 'baz')) 409 410 def test_sets(self): 411 'Verify the pretty-printing of sets' 412 if (gdb_major_version, gdb_minor_version) < (7, 3): 413 self.skipTest("pretty-printing of sets needs gdb 7.3 or later") 414 self.assertGdbRepr(set(), "set()") 415 self.assertGdbRepr(set(['a']), "{'a'}") 416 # PYTHONHASHSEED is need to get the exact frozenset item order 417 if not sys.flags.ignore_environment: 418 self.assertGdbRepr(set(['a', 'b']), "{'a', 'b'}") 419 self.assertGdbRepr(set([4, 5, 6]), "{4, 5, 6}") 420 421 # Ensure that we handle sets containing the "dummy" key value, 422 # which happens on deletion: 423 gdb_repr, gdb_output = self.get_gdb_repr('''s = set(['a','b']) 424s.remove('a') 425id(s)''') 426 self.assertEqual(gdb_repr, "{'b'}") 427 428 def test_frozensets(self): 429 'Verify the pretty-printing of frozensets' 430 if (gdb_major_version, gdb_minor_version) < (7, 3): 431 self.skipTest("pretty-printing of frozensets needs gdb 7.3 or later") 432 self.assertGdbRepr(frozenset(), "frozenset()") 433 self.assertGdbRepr(frozenset(['a']), "frozenset({'a'})") 434 # PYTHONHASHSEED is need to get the exact frozenset item order 435 if not sys.flags.ignore_environment: 436 self.assertGdbRepr(frozenset(['a', 'b']), "frozenset({'a', 'b'})") 437 self.assertGdbRepr(frozenset([4, 5, 6]), "frozenset({4, 5, 6})") 438 439 def test_exceptions(self): 440 # Test a RuntimeError 441 gdb_repr, gdb_output = self.get_gdb_repr(''' 442try: 443 raise RuntimeError("I am an error") 444except RuntimeError as e: 445 id(e) 446''') 447 self.assertEqual(gdb_repr, 448 "RuntimeError('I am an error',)") 449 450 451 # Test division by zero: 452 gdb_repr, gdb_output = self.get_gdb_repr(''' 453try: 454 a = 1 / 0 455except ZeroDivisionError as e: 456 id(e) 457''') 458 self.assertEqual(gdb_repr, 459 "ZeroDivisionError('division by zero',)") 460 461 def test_modern_class(self): 462 'Verify the pretty-printing of new-style class instances' 463 gdb_repr, gdb_output = self.get_gdb_repr(''' 464class Foo: 465 pass 466foo = Foo() 467foo.an_int = 42 468id(foo)''') 469 m = re.match(r'<Foo\(an_int=42\) at remote 0x-?[0-9a-f]+>', gdb_repr) 470 self.assertTrue(m, 471 msg='Unexpected new-style class rendering %r' % gdb_repr) 472 473 def test_subclassing_list(self): 474 'Verify the pretty-printing of an instance of a list subclass' 475 gdb_repr, gdb_output = self.get_gdb_repr(''' 476class Foo(list): 477 pass 478foo = Foo() 479foo += [1, 2, 3] 480foo.an_int = 42 481id(foo)''') 482 m = re.match(r'<Foo\(an_int=42\) at remote 0x-?[0-9a-f]+>', gdb_repr) 483 484 self.assertTrue(m, 485 msg='Unexpected new-style class rendering %r' % gdb_repr) 486 487 def test_subclassing_tuple(self): 488 'Verify the pretty-printing of an instance of a tuple subclass' 489 # This should exercise the negative tp_dictoffset code in the 490 # new-style class support 491 gdb_repr, gdb_output = self.get_gdb_repr(''' 492class Foo(tuple): 493 pass 494foo = Foo((1, 2, 3)) 495foo.an_int = 42 496id(foo)''') 497 m = re.match(r'<Foo\(an_int=42\) at remote 0x-?[0-9a-f]+>', gdb_repr) 498 499 self.assertTrue(m, 500 msg='Unexpected new-style class rendering %r' % gdb_repr) 501 502 def assertSane(self, source, corruption, exprepr=None): 503 '''Run Python under gdb, corrupting variables in the inferior process 504 immediately before taking a backtrace. 505 506 Verify that the variable's representation is the expected failsafe 507 representation''' 508 if corruption: 509 cmds_after_breakpoint=[corruption, 'backtrace'] 510 else: 511 cmds_after_breakpoint=['backtrace'] 512 513 gdb_repr, gdb_output = \ 514 self.get_gdb_repr(source, 515 cmds_after_breakpoint=cmds_after_breakpoint) 516 if exprepr: 517 if gdb_repr == exprepr: 518 # gdb managed to print the value in spite of the corruption; 519 # this is good (see http://bugs.python.org/issue8330) 520 return 521 522 # Match anything for the type name; 0xDEADBEEF could point to 523 # something arbitrary (see http://bugs.python.org/issue8330) 524 pattern = '<.* at remote 0x-?[0-9a-f]+>' 525 526 m = re.match(pattern, gdb_repr) 527 if not m: 528 self.fail('Unexpected gdb representation: %r\n%s' % \ 529 (gdb_repr, gdb_output)) 530 531 def test_NULL_ptr(self): 532 'Ensure that a NULL PyObject* is handled gracefully' 533 gdb_repr, gdb_output = ( 534 self.get_gdb_repr('id(42)', 535 cmds_after_breakpoint=['set variable v=0', 536 'backtrace']) 537 ) 538 539 self.assertEqual(gdb_repr, '0x0') 540 541 def test_NULL_ob_type(self): 542 'Ensure that a PyObject* with NULL ob_type is handled gracefully' 543 self.assertSane('id(42)', 544 'set v->ob_type=0') 545 546 def test_corrupt_ob_type(self): 547 'Ensure that a PyObject* with a corrupt ob_type is handled gracefully' 548 self.assertSane('id(42)', 549 'set v->ob_type=0xDEADBEEF', 550 exprepr='42') 551 552 def test_corrupt_tp_flags(self): 553 'Ensure that a PyObject* with a type with corrupt tp_flags is handled' 554 self.assertSane('id(42)', 555 'set v->ob_type->tp_flags=0x0', 556 exprepr='42') 557 558 def test_corrupt_tp_name(self): 559 'Ensure that a PyObject* with a type with corrupt tp_name is handled' 560 self.assertSane('id(42)', 561 'set v->ob_type->tp_name=0xDEADBEEF', 562 exprepr='42') 563 564 def test_builtins_help(self): 565 'Ensure that the new-style class _Helper in site.py can be handled' 566 567 if sys.flags.no_site: 568 self.skipTest("need site module, but -S option was used") 569 570 # (this was the issue causing tracebacks in 571 # http://bugs.python.org/issue8032#msg100537 ) 572 gdb_repr, gdb_output = self.get_gdb_repr('id(__builtins__.help)', import_site=True) 573 574 m = re.match(r'<_Helper\(\) at remote 0x-?[0-9a-f]+>', gdb_repr) 575 self.assertTrue(m, 576 msg='Unexpected rendering %r' % gdb_repr) 577 578 def test_selfreferential_list(self): 579 '''Ensure that a reference loop involving a list doesn't lead proxyval 580 into an infinite loop:''' 581 gdb_repr, gdb_output = \ 582 self.get_gdb_repr("a = [3, 4, 5] ; a.append(a) ; id(a)") 583 self.assertEqual(gdb_repr, '[3, 4, 5, [...]]') 584 585 gdb_repr, gdb_output = \ 586 self.get_gdb_repr("a = [3, 4, 5] ; b = [a] ; a.append(b) ; id(a)") 587 self.assertEqual(gdb_repr, '[3, 4, 5, [[...]]]') 588 589 def test_selfreferential_dict(self): 590 '''Ensure that a reference loop involving a dict doesn't lead proxyval 591 into an infinite loop:''' 592 gdb_repr, gdb_output = \ 593 self.get_gdb_repr("a = {} ; b = {'bar':a} ; a['foo'] = b ; id(a)") 594 595 self.assertEqual(gdb_repr, "{'foo': {'bar': {...}}}") 596 597 def test_selfreferential_old_style_instance(self): 598 gdb_repr, gdb_output = \ 599 self.get_gdb_repr(''' 600class Foo: 601 pass 602foo = Foo() 603foo.an_attr = foo 604id(foo)''') 605 self.assertTrue(re.match(r'<Foo\(an_attr=<\.\.\.>\) at remote 0x-?[0-9a-f]+>', 606 gdb_repr), 607 'Unexpected gdb representation: %r\n%s' % \ 608 (gdb_repr, gdb_output)) 609 610 def test_selfreferential_new_style_instance(self): 611 gdb_repr, gdb_output = \ 612 self.get_gdb_repr(''' 613class Foo(object): 614 pass 615foo = Foo() 616foo.an_attr = foo 617id(foo)''') 618 self.assertTrue(re.match(r'<Foo\(an_attr=<\.\.\.>\) at remote 0x-?[0-9a-f]+>', 619 gdb_repr), 620 'Unexpected gdb representation: %r\n%s' % \ 621 (gdb_repr, gdb_output)) 622 623 gdb_repr, gdb_output = \ 624 self.get_gdb_repr(''' 625class Foo(object): 626 pass 627a = Foo() 628b = Foo() 629a.an_attr = b 630b.an_attr = a 631id(a)''') 632 self.assertTrue(re.match(r'<Foo\(an_attr=<Foo\(an_attr=<\.\.\.>\) at remote 0x-?[0-9a-f]+>\) at remote 0x-?[0-9a-f]+>', 633 gdb_repr), 634 'Unexpected gdb representation: %r\n%s' % \ 635 (gdb_repr, gdb_output)) 636 637 def test_truncation(self): 638 'Verify that very long output is truncated' 639 gdb_repr, gdb_output = self.get_gdb_repr('id(list(range(1000)))') 640 self.assertEqual(gdb_repr, 641 "[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, " 642 "14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, " 643 "27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, " 644 "40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, " 645 "53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, " 646 "66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, " 647 "79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, " 648 "92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, " 649 "104, 105, 106, 107, 108, 109, 110, 111, 112, 113, " 650 "114, 115, 116, 117, 118, 119, 120, 121, 122, 123, " 651 "124, 125, 126, 127, 128, 129, 130, 131, 132, 133, " 652 "134, 135, 136, 137, 138, 139, 140, 141, 142, 143, " 653 "144, 145, 146, 147, 148, 149, 150, 151, 152, 153, " 654 "154, 155, 156, 157, 158, 159, 160, 161, 162, 163, " 655 "164, 165, 166, 167, 168, 169, 170, 171, 172, 173, " 656 "174, 175, 176, 177, 178, 179, 180, 181, 182, 183, " 657 "184, 185, 186, 187, 188, 189, 190, 191, 192, 193, " 658 "194, 195, 196, 197, 198, 199, 200, 201, 202, 203, " 659 "204, 205, 206, 207, 208, 209, 210, 211, 212, 213, " 660 "214, 215, 216, 217, 218, 219, 220, 221, 222, 223, " 661 "224, 225, 226...(truncated)") 662 self.assertEqual(len(gdb_repr), 663 1024 + len('...(truncated)')) 664 665 def test_builtin_method(self): 666 gdb_repr, gdb_output = self.get_gdb_repr('import sys; id(sys.stdout.readlines)') 667 self.assertTrue(re.match(r'<built-in method readlines of _io.TextIOWrapper object at remote 0x-?[0-9a-f]+>', 668 gdb_repr), 669 'Unexpected gdb representation: %r\n%s' % \ 670 (gdb_repr, gdb_output)) 671 672 def test_frames(self): 673 gdb_output = self.get_stack_trace(''' 674import sys 675def foo(a, b, c): 676 return sys._getframe(0) 677 678f = foo(3, 4, 5) 679id(f)''', 680 breakpoint='builtin_id', 681 cmds_after_breakpoint=['print (PyFrameObject*)v'] 682 ) 683 self.assertTrue(re.match(r'.*\s+\$1 =\s+Frame 0x-?[0-9a-f]+, for file <string>, line 4, in foo \(a=3.*', 684 gdb_output, 685 re.DOTALL), 686 'Unexpected gdb representation: %r\n%s' % (gdb_output, gdb_output)) 687 688@unittest.skipIf(python_is_optimized(), 689 "Python was compiled with optimizations") 690class PyListTests(DebuggerTests): 691 def assertListing(self, expected, actual): 692 self.assertEndsWith(actual, expected) 693 694 def test_basic_command(self): 695 'Verify that the "py-list" command works' 696 bt = self.get_stack_trace(script=self.get_sample_script(), 697 cmds_after_breakpoint=['py-list']) 698 699 self.assertListing(' 5 \n' 700 ' 6 def bar(a, b, c):\n' 701 ' 7 baz(a, b, c)\n' 702 ' 8 \n' 703 ' 9 def baz(*args):\n' 704 ' >10 id(42)\n' 705 ' 11 \n' 706 ' 12 foo(1, 2, 3)\n', 707 bt) 708 709 def test_one_abs_arg(self): 710 'Verify the "py-list" command with one absolute argument' 711 bt = self.get_stack_trace(script=self.get_sample_script(), 712 cmds_after_breakpoint=['py-list 9']) 713 714 self.assertListing(' 9 def baz(*args):\n' 715 ' >10 id(42)\n' 716 ' 11 \n' 717 ' 12 foo(1, 2, 3)\n', 718 bt) 719 720 def test_two_abs_args(self): 721 'Verify the "py-list" command with two absolute arguments' 722 bt = self.get_stack_trace(script=self.get_sample_script(), 723 cmds_after_breakpoint=['py-list 1,3']) 724 725 self.assertListing(' 1 # Sample script for use by test_gdb.py\n' 726 ' 2 \n' 727 ' 3 def foo(a, b, c):\n', 728 bt) 729 730SAMPLE_WITH_C_CALL = """ 731 732from _testcapi import pyobject_fastcall 733 734def foo(a, b, c): 735 bar(a, b, c) 736 737def bar(a, b, c): 738 pyobject_fastcall(baz, (a, b, c)) 739 740def baz(*args): 741 id(42) 742 743foo(1, 2, 3) 744 745""" 746 747 748class StackNavigationTests(DebuggerTests): 749 @unittest.skipUnless(HAS_PYUP_PYDOWN, "test requires py-up/py-down commands") 750 @unittest.skipIf(python_is_optimized(), 751 "Python was compiled with optimizations") 752 def test_pyup_command(self): 753 'Verify that the "py-up" command works' 754 bt = self.get_stack_trace(source=SAMPLE_WITH_C_CALL, 755 cmds_after_breakpoint=['py-up', 'py-up']) 756 self.assertMultilineMatches(bt, 757 r'''^.* 758#[0-9]+ Frame 0x-?[0-9a-f]+, for file <string>, line 12, in baz \(args=\(1, 2, 3\)\) 759#[0-9]+ <built-in method pyobject_fastcall of module object at remote 0x[0-9a-f]+> 760$''') 761 762 @unittest.skipUnless(HAS_PYUP_PYDOWN, "test requires py-up/py-down commands") 763 def test_down_at_bottom(self): 764 'Verify handling of "py-down" at the bottom of the stack' 765 bt = self.get_stack_trace(script=self.get_sample_script(), 766 cmds_after_breakpoint=['py-down']) 767 self.assertEndsWith(bt, 768 'Unable to find a newer python frame\n') 769 770 @unittest.skipUnless(HAS_PYUP_PYDOWN, "test requires py-up/py-down commands") 771 def test_up_at_top(self): 772 'Verify handling of "py-up" at the top of the stack' 773 bt = self.get_stack_trace(script=self.get_sample_script(), 774 cmds_after_breakpoint=['py-up'] * 5) 775 self.assertEndsWith(bt, 776 'Unable to find an older python frame\n') 777 778 @unittest.skipUnless(HAS_PYUP_PYDOWN, "test requires py-up/py-down commands") 779 @unittest.skipIf(python_is_optimized(), 780 "Python was compiled with optimizations") 781 def test_up_then_down(self): 782 'Verify "py-up" followed by "py-down"' 783 bt = self.get_stack_trace(source=SAMPLE_WITH_C_CALL, 784 cmds_after_breakpoint=['py-up', 'py-up', 'py-down']) 785 self.assertMultilineMatches(bt, 786 r'''^.* 787#[0-9]+ Frame 0x-?[0-9a-f]+, for file <string>, line 12, in baz \(args=\(1, 2, 3\)\) 788#[0-9]+ <built-in method pyobject_fastcall of module object at remote 0x[0-9a-f]+> 789#[0-9]+ Frame 0x-?[0-9a-f]+, for file <string>, line 12, in baz \(args=\(1, 2, 3\)\) 790$''') 791 792class PyBtTests(DebuggerTests): 793 @unittest.skipIf(python_is_optimized(), 794 "Python was compiled with optimizations") 795 def test_bt(self): 796 'Verify that the "py-bt" command works' 797 bt = self.get_stack_trace(script=self.get_sample_script(), 798 cmds_after_breakpoint=['py-bt']) 799 self.assertMultilineMatches(bt, 800 r'''^.* 801Traceback \(most recent call first\): 802 <built-in method id of module object .*> 803 File ".*gdb_sample.py", line 10, in baz 804 id\(42\) 805 File ".*gdb_sample.py", line 7, in bar 806 baz\(a, b, c\) 807 File ".*gdb_sample.py", line 4, in foo 808 bar\(a=a, b=b, c=c\) 809 File ".*gdb_sample.py", line 12, in <module> 810 foo\(1, 2, 3\) 811''') 812 813 @unittest.skipIf(python_is_optimized(), 814 "Python was compiled with optimizations") 815 def test_bt_full(self): 816 'Verify that the "py-bt-full" command works' 817 bt = self.get_stack_trace(script=self.get_sample_script(), 818 cmds_after_breakpoint=['py-bt-full']) 819 self.assertMultilineMatches(bt, 820 r'''^.* 821#[0-9]+ Frame 0x-?[0-9a-f]+, for file .*gdb_sample.py, line 7, in bar \(a=1, b=2, c=3\) 822 baz\(a, b, c\) 823#[0-9]+ Frame 0x-?[0-9a-f]+, for file .*gdb_sample.py, line 4, in foo \(a=1, b=2, c=3\) 824 bar\(a=a, b=b, c=c\) 825#[0-9]+ Frame 0x-?[0-9a-f]+, for file .*gdb_sample.py, line 12, in <module> \(\) 826 foo\(1, 2, 3\) 827''') 828 829 @unittest.skipIf(python_is_optimized(), 830 "Python was compiled with optimizations") 831 def test_threads(self): 832 'Verify that "py-bt" indicates threads that are waiting for the GIL' 833 cmd = ''' 834from threading import Thread 835 836class TestThread(Thread): 837 # These threads would run forever, but we'll interrupt things with the 838 # debugger 839 def run(self): 840 i = 0 841 while 1: 842 i += 1 843 844t = {} 845for i in range(4): 846 t[i] = TestThread() 847 t[i].start() 848 849# Trigger a breakpoint on the main thread 850id(42) 851 852''' 853 # Verify with "py-bt": 854 gdb_output = self.get_stack_trace(cmd, 855 cmds_after_breakpoint=['thread apply all py-bt']) 856 self.assertIn('Waiting for the GIL', gdb_output) 857 858 # Verify with "py-bt-full": 859 gdb_output = self.get_stack_trace(cmd, 860 cmds_after_breakpoint=['thread apply all py-bt-full']) 861 self.assertIn('Waiting for the GIL', gdb_output) 862 863 @unittest.skipIf(python_is_optimized(), 864 "Python was compiled with optimizations") 865 # Some older versions of gdb will fail with 866 # "Cannot find new threads: generic error" 867 # unless we add LD_PRELOAD=PATH-TO-libpthread.so.1 as a workaround 868 def test_gc(self): 869 'Verify that "py-bt" indicates if a thread is garbage-collecting' 870 cmd = ('from gc import collect\n' 871 'id(42)\n' 872 'def foo():\n' 873 ' collect()\n' 874 'def bar():\n' 875 ' foo()\n' 876 'bar()\n') 877 # Verify with "py-bt": 878 gdb_output = self.get_stack_trace(cmd, 879 cmds_after_breakpoint=['break update_refs', 'continue', 'py-bt'], 880 ) 881 self.assertIn('Garbage-collecting', gdb_output) 882 883 # Verify with "py-bt-full": 884 gdb_output = self.get_stack_trace(cmd, 885 cmds_after_breakpoint=['break update_refs', 'continue', 'py-bt-full'], 886 ) 887 self.assertIn('Garbage-collecting', gdb_output) 888 889 890 @unittest.skipIf(python_is_optimized(), 891 "Python was compiled with optimizations") 892 # Some older versions of gdb will fail with 893 # "Cannot find new threads: generic error" 894 # unless we add LD_PRELOAD=PATH-TO-libpthread.so.1 as a workaround 895 # 896 # gdb will also generate many erroneous errors such as: 897 # Function "meth_varargs" not defined. 898 # This is because we are calling functions from an "external" module 899 # (_testcapimodule) rather than compiled-in functions. It seems difficult 900 # to suppress these. See also the comment in DebuggerTests.get_stack_trace 901 def test_pycfunction(self): 902 'Verify that "py-bt" displays invocations of PyCFunction instances' 903 # bpo-46600: If the compiler inlines _null_to_none() in meth_varargs() 904 # (ex: clang -Og), _null_to_none() is the frame #1. Otherwise, 905 # meth_varargs() is the frame #1. 906 expected_frame = r'#(1|2)' 907 # Various optimizations multiply the code paths by which these are 908 # called, so test a variety of calling conventions. 909 for func_name, args in ( 910 ('meth_varargs', ''), 911 ('meth_varargs_keywords', ''), 912 ('meth_o', '[]'), 913 ('meth_noargs', ''), 914 ('meth_fastcall', ''), 915 ('meth_fastcall_keywords', ''), 916 ): 917 for obj in ( 918 '_testcapi', 919 '_testcapi.MethClass', 920 '_testcapi.MethClass()', 921 '_testcapi.MethStatic()', 922 923 # XXX: bound methods don't yet give nice tracebacks 924 # '_testcapi.MethInstance()', 925 ): 926 with self.subTest(f'{obj}.{func_name}'): 927 cmd = textwrap.dedent(f''' 928 import _testcapi 929 def foo(): 930 {obj}.{func_name}({args}) 931 def bar(): 932 foo() 933 bar() 934 ''') 935 # Verify with "py-bt": 936 gdb_output = self.get_stack_trace( 937 cmd, 938 breakpoint=func_name, 939 cmds_after_breakpoint=['bt', 'py-bt'], 940 # bpo-45207: Ignore 'Function "meth_varargs" not 941 # defined.' message in stderr. 942 ignore_stderr=True, 943 ) 944 self.assertIn(f'<built-in method {func_name}', gdb_output) 945 946 # Verify with "py-bt-full": 947 gdb_output = self.get_stack_trace( 948 cmd, 949 breakpoint=func_name, 950 cmds_after_breakpoint=['py-bt-full'], 951 # bpo-45207: Ignore 'Function "meth_varargs" not 952 # defined.' message in stderr. 953 ignore_stderr=True, 954 ) 955 regex = expected_frame 956 regex += re.escape(f' <built-in method {func_name}') 957 self.assertRegex(gdb_output, regex) 958 959 @unittest.skipIf(python_is_optimized(), 960 "Python was compiled with optimizations") 961 def test_wrapper_call(self): 962 cmd = textwrap.dedent(''' 963 class MyList(list): 964 def __init__(self): 965 super().__init__() # wrapper_call() 966 967 id("first break point") 968 l = MyList() 969 ''') 970 cmds_after_breakpoint = ['break wrapper_call', 'continue'] 971 if CET_PROTECTION: 972 # bpo-32962: same case as in get_stack_trace(): 973 # we need an additional 'next' command in order to read 974 # arguments of the innermost function of the call stack. 975 cmds_after_breakpoint.append('next') 976 cmds_after_breakpoint.append('py-bt') 977 978 # Verify with "py-bt": 979 gdb_output = self.get_stack_trace(cmd, 980 cmds_after_breakpoint=cmds_after_breakpoint) 981 self.assertRegex(gdb_output, 982 r"<method-wrapper u?'__init__' of MyList object at ") 983 984class PyPrintTests(DebuggerTests): 985 @unittest.skipIf(python_is_optimized(), 986 "Python was compiled with optimizations") 987 def test_basic_command(self): 988 'Verify that the "py-print" command works' 989 bt = self.get_stack_trace(source=SAMPLE_WITH_C_CALL, 990 cmds_after_breakpoint=['py-up', 'py-print args']) 991 self.assertMultilineMatches(bt, 992 r".*\nlocal 'args' = \(1, 2, 3\)\n.*") 993 994 @unittest.skipIf(python_is_optimized(), 995 "Python was compiled with optimizations") 996 @unittest.skipUnless(HAS_PYUP_PYDOWN, "test requires py-up/py-down commands") 997 def test_print_after_up(self): 998 bt = self.get_stack_trace(source=SAMPLE_WITH_C_CALL, 999 cmds_after_breakpoint=['py-up', 'py-up', 'py-print c', 'py-print b', 'py-print a']) 1000 self.assertMultilineMatches(bt, 1001 r".*\nlocal 'c' = 3\nlocal 'b' = 2\nlocal 'a' = 1\n.*") 1002 1003 @unittest.skipIf(python_is_optimized(), 1004 "Python was compiled with optimizations") 1005 def test_printing_global(self): 1006 bt = self.get_stack_trace(script=self.get_sample_script(), 1007 cmds_after_breakpoint=['py-up', 'py-print __name__']) 1008 self.assertMultilineMatches(bt, 1009 r".*\nglobal '__name__' = '__main__'\n.*") 1010 1011 @unittest.skipIf(python_is_optimized(), 1012 "Python was compiled with optimizations") 1013 def test_printing_builtin(self): 1014 bt = self.get_stack_trace(script=self.get_sample_script(), 1015 cmds_after_breakpoint=['py-up', 'py-print len']) 1016 self.assertMultilineMatches(bt, 1017 r".*\nbuiltin 'len' = <built-in method len of module object at remote 0x-?[0-9a-f]+>\n.*") 1018 1019class PyLocalsTests(DebuggerTests): 1020 @unittest.skipIf(python_is_optimized(), 1021 "Python was compiled with optimizations") 1022 def test_basic_command(self): 1023 bt = self.get_stack_trace(script=self.get_sample_script(), 1024 cmds_after_breakpoint=['py-up', 'py-locals']) 1025 self.assertMultilineMatches(bt, 1026 r".*\nargs = \(1, 2, 3\)\n.*") 1027 1028 @unittest.skipUnless(HAS_PYUP_PYDOWN, "test requires py-up/py-down commands") 1029 @unittest.skipIf(python_is_optimized(), 1030 "Python was compiled with optimizations") 1031 def test_locals_after_up(self): 1032 bt = self.get_stack_trace(script=self.get_sample_script(), 1033 cmds_after_breakpoint=['py-up', 'py-up', 'py-locals']) 1034 self.assertMultilineMatches(bt, 1035 r'''^.* 1036Locals for foo 1037a = 1 1038b = 2 1039c = 3 1040Locals for <module> 1041.*$''') 1042 1043 1044def setUpModule(): 1045 if support.verbose: 1046 print("GDB version %s.%s:" % (gdb_major_version, gdb_minor_version)) 1047 for line in gdb_version.splitlines(): 1048 print(" " * 4 + line) 1049 1050 1051if __name__ == "__main__": 1052 unittest.main() 1053