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