text: # Verify that gdb can pretty-print the various PyObject* types
  #
  # The code for testing gdb was adapted from similar work in Unladen Swallow's
  # Lib/test/test_jit_gdb.py
  
  import os
  import re
  import pprint
  import subprocess
  import sys
  import sysconfig
  import unittest
  import locale
  
  # Is this Python configured to support threads?
  try:
      import _thread
  except ImportError:
      _thread = None
  
  from test import support
  from test.support import run_unittest, findfile, python_is_optimized
  
  def get_gdb_version():
      try:
          proc = subprocess.Popen(["gdb", "-nx", "--version"],
                                  stdout=subprocess.PIPE,
                                  universal_newlines=True)
          with proc:
              version = proc.communicate()[0]
      except OSError:
          # This is what "no gdb" looks like.  There may, however, be other
          # errors that manifest this way too.
          raise unittest.SkipTest("Couldn't find gdb on the path")
  
      # Regex to parse:
      # 'GNU gdb (GDB; SUSE Linux Enterprise 12) 7.7\n' -> 7.7
      # 'GNU gdb (GDB) Fedora 7.9.1-17.fc22\n' -> 7.9
      # 'GNU gdb 6.1.1 [FreeBSD]\n' -> 6.1
      # 'GNU gdb (GDB) Fedora (7.5.1-37.fc18)\n' -> 7.5
      match = re.search(r"^GNU gdb.*?\b(\d+)\.(\d+)", version)
      if match is None:
          raise Exception("unable to parse GDB version: %r" % version)
      return (version, int(match.group(1)), int(match.group(2)))
  
  gdb_version, gdb_major_version, gdb_minor_version = get_gdb_version()
  if gdb_major_version < 7:
      raise unittest.SkipTest("gdb versions before 7.0 didn't support python "
                              "embedding. Saw %s.%s:\n%s"
                              % (gdb_major_version, gdb_minor_version,
                                 gdb_version))
  
  if not sysconfig.is_python_build():
      raise unittest.SkipTest("test_gdb only works on source builds at the moment.")
  
  # Location of custom hooks file in a repository checkout.
  checkout_hook_path = os.path.join(os.path.dirname(sys.executable),
                                    'python-gdb.py')
  
  PYTHONHASHSEED = '123'
  
  def run_gdb(*args, **env_vars):
      """Runs gdb in --batch mode with the additional arguments given by *args.
  
      Returns its (stdout, stderr) decoded from utf-8 using the replace handler.
      """
      if env_vars:
          env = os.environ.copy()
          env.update(env_vars)
      else:
          env = None
      # -nx: Do not execute commands from any .gdbinit initialization files
      #      (issue #22188)
      base_cmd = ('gdb', '--batch', '-nx')
      if (gdb_major_version, gdb_minor_version) >= (7, 4):
          base_cmd += ('-iex', 'add-auto-load-safe-path ' + checkout_hook_path)
      proc = subprocess.Popen(base_cmd + args,
                              stdout=subprocess.PIPE,
                              stderr=subprocess.PIPE,
                              env=env)
      with proc:
          out, err = proc.communicate()
      return out.decode('utf-8', 'replace'), err.decode('utf-8', 'replace')
  
  # Verify that "gdb" was built with the embedded python support enabled:
  gdbpy_version, _ = run_gdb("--eval-command=python import sys; print(sys.version_info)")
  if not gdbpy_version:
      raise unittest.SkipTest("gdb not built with embedded python support")
  
  # Verify that "gdb" can load our custom hooks, as OS security settings may
  # disallow this without a customised .gdbinit.
  cmd = ['--args', sys.executable]
  _, gdbpy_errors = run_gdb('--args', sys.executable)
  if "auto-loading has been declined" in gdbpy_errors:
      msg = "gdb security settings prevent use of custom hooks: "
      raise unittest.SkipTest(msg + gdbpy_errors.rstrip())
  
  def gdb_has_frame_select():
      # Does this build of gdb have gdb.Frame.select ?
      stdout, _ = run_gdb("--eval-command=python print(dir(gdb.Frame))")
      m = re.match(r'.*\[(.*)\].*', stdout)
      if not m:
          raise unittest.SkipTest("Unable to parse output from gdb.Frame.select test")
      gdb_frame_dir = m.group(1).split(', ')
      return "'select'" in gdb_frame_dir
  
  HAS_PYUP_PYDOWN = gdb_has_frame_select()
  
  BREAKPOINT_FN='builtin_id'
  
  class DebuggerTests(unittest.TestCase):
  
      """Test that the debugger can debug Python."""
  
      def get_stack_trace(self, source=None, script=None,
                          breakpoint=BREAKPOINT_FN,
                          cmds_after_breakpoint=None,
                          import_site=False):
          '''
          Run 'python -c SOURCE' under gdb with a breakpoint.
  
          Support injecting commands after the breakpoint is reached
  
          Returns the stdout from gdb
  
          cmds_after_breakpoint: if provided, a list of strings: gdb commands
          '''
          # We use "set breakpoint pending yes" to avoid blocking with a:
          #   Function "foo" not defined.
          #   Make breakpoint pending on future shared library load? (y or [n])
          # error, which typically happens python is dynamically linked (the
          # breakpoints of interest are to be found in the shared library)
          # When this happens, we still get:
          #   Function "textiowrapper_write" not defined.
          # emitted to stderr each time, alas.
  
          # Initially I had "--eval-command=continue" here, but removed it to
          # avoid repeated print breakpoints when traversing hierarchical data
          # structures
  
          # Generate a list of commands in gdb's language:
          commands = ['set breakpoint pending yes',
                      'break %s' % breakpoint,
  
                      # The tests assume that the first frame of printed
                      #  backtrace will not contain program counter,
                      #  that is however not guaranteed by gdb
                      #  therefore we need to use 'set print address off' to
                      #  make sure the counter is not there. For example:
                      # #0 in PyObject_Print ...
                      #  is assumed, but sometimes this can be e.g.
                      # #0 0x00003fffb7dd1798 in PyObject_Print ...
                      'set print address off',
  
                      'run']
  
          # GDB as of 7.4 onwards can distinguish between the
          # value of a variable at entry vs current value:
          #   http://sourceware.org/gdb/onlinedocs/gdb/Variables.html
          # which leads to the selftests failing with errors like this:
          #   AssertionError: 'v@entry=()' != '()'
          # Disable this:
          if (gdb_major_version, gdb_minor_version) >= (7, 4):
              commands += ['set print entry-values no']
  
          if cmds_after_breakpoint:
              commands += cmds_after_breakpoint
          else:
              commands += ['backtrace']
  
          # print commands
  
          # Use "commands" to generate the arguments with which to invoke "gdb":
          args = ["gdb", "--batch", "-nx"]
          args += ['--eval-command=%s' % cmd for cmd in commands]
          args += ["--args",
                   sys.executable]
  
          if not import_site:
              # -S suppresses the default 'import site'
              args += ["-S"]
  
          if source:
              args += ["-c", source]
          elif script:
              args += [script]
  
          # print args
          # print (' '.join(args))
  
          # Use "args" to invoke gdb, capturing stdout, stderr:
          out, err = run_gdb(*args, PYTHONHASHSEED=PYTHONHASHSEED)
  
          errlines = err.splitlines()
          unexpected_errlines = []
  
          # Ignore some benign messages on stderr.
          ignore_patterns = (
              'Function "%s" not defined.' % breakpoint,
              "warning: no loadable sections found in added symbol-file"
              " system-supplied DSO",
              "warning: Unable to find libthread_db matching"
              " inferior's thread library, thread debugging will"
              " not be available.",
              "warning: Cannot initialize thread debugging"
              " library: Debugger service failed",
              'warning: Could not load shared library symbols for '
              'linux-vdso.so',
              'warning: Could not load shared library symbols for '
              'linux-gate.so',
              'warning: Could not load shared library symbols for '
              'linux-vdso64.so',
              'Do you need "set solib-search-path" or '
              '"set sysroot"?',
              'warning: Source file is more recent than executable.',
              # Issue #19753: missing symbols on System Z
              'Missing separate debuginfo for ',
              'Try: zypper install -C ',
              )
          for line in errlines:
              if not line.startswith(ignore_patterns):
                  unexpected_errlines.append(line)
  
          # Ensure no unexpected error messages:
          self.assertEqual(unexpected_errlines, [])
          return out
  
      def get_gdb_repr(self, source,
                       cmds_after_breakpoint=None,
                       import_site=False):
          # Given an input python source representation of data,
          # run "python -c'id(DATA)'" under gdb with a breakpoint on
          # builtin_id and scrape out gdb's representation of the "op"
          # parameter, and verify that the gdb displays the same string
          #
          # Verify that the gdb displays the expected string
          #
          # For a nested structure, the first time we hit the breakpoint will
          # give us the top-level structure
  
          # NOTE: avoid decoding too much of the traceback as some
          # undecodable characters may lurk there in optimized mode
          # (issue #19743).
          cmds_after_breakpoint = cmds_after_breakpoint or ["backtrace 1"]
          gdb_output = self.get_stack_trace(source, breakpoint=BREAKPOINT_FN,
                                            cmds_after_breakpoint=cmds_after_breakpoint,
                                            import_site=import_site)
          # gdb can insert additional '\n' and space characters in various places
          # in its output, depending on the width of the terminal it's connected
          # to (using its "wrap_here" function)
          m = re.match('.*#0\s+builtin_id\s+\(self\=.*,\s+v=\s*(.*?)\)\s+at\s+\S*Python/bltinmodule.c.*',
                       gdb_output, re.DOTALL)
          if not m:
              self.fail('Unexpected gdb output: %r\n%s' % (gdb_output, gdb_output))
          return m.group(1), gdb_output
  
      def assertEndsWith(self, actual, exp_end):
          '''Ensure that the given "actual" string ends with "exp_end"'''
          self.assertTrue(actual.endswith(exp_end),
                          msg='%r did not end with %r' % (actual, exp_end))
  
      def assertMultilineMatches(self, actual, pattern):
          m = re.match(pattern, actual, re.DOTALL)
          if not m:
              self.fail(msg='%r did not match %r' % (actual, pattern))
  
      def get_sample_script(self):
          return findfile('gdb_sample.py')
  
  class PrettyPrintTests(DebuggerTests):
      def test_getting_backtrace(self):
          gdb_output = self.get_stack_trace('id(42)')
          self.assertTrue(BREAKPOINT_FN in gdb_output)
  
      def assertGdbRepr(self, val, exp_repr=None):
          # Ensure that gdb's rendering of the value in a debugged process
          # matches repr(value) in this process:
          gdb_repr, gdb_output = self.get_gdb_repr('id(' + ascii(val) + ')')
          if not exp_repr:
              exp_repr = repr(val)
          self.assertEqual(gdb_repr, exp_repr,
                           ('%r did not equal expected %r; full output was:\n%s'
                            % (gdb_repr, exp_repr, gdb_output)))
  
      def test_int(self):
          'Verify the pretty-printing of various int values'
          self.assertGdbRepr(42)
          self.assertGdbRepr(0)
          self.assertGdbRepr(-7)
          self.assertGdbRepr(1000000000000)
          self.assertGdbRepr(-1000000000000000)
  
      def test_singletons(self):
          'Verify the pretty-printing of True, False and None'
          self.assertGdbRepr(True)
          self.assertGdbRepr(False)
          self.assertGdbRepr(None)
  
      def test_dicts(self):
          'Verify the pretty-printing of dictionaries'
          self.assertGdbRepr({})
          self.assertGdbRepr({'foo': 'bar'}, "{'foo': 'bar'}")
          self.assertGdbRepr({'foo': 'bar', 'douglas': 42}, "{'douglas': 42, 'foo': 'bar'}")
  
      def test_lists(self):
          'Verify the pretty-printing of lists'
          self.assertGdbRepr([])
          self.assertGdbRepr(list(range(5)))
  
      def test_bytes(self):
          'Verify the pretty-printing of bytes'
          self.assertGdbRepr(b'')
          self.assertGdbRepr(b'And now for something hopefully the same')
          self.assertGdbRepr(b'string with embedded NUL here \0 and then some more text')
          self.assertGdbRepr(b'this is a tab:\t'
                             b' this is a slash-N:\n'
                             b' this is a slash-R:\r'
                             )
  
          self.assertGdbRepr(b'this is byte 255:\xff and byte 128:\x80')
  
          self.assertGdbRepr(bytes([b for b in range(255)]))
  
      def test_strings(self):
          'Verify the pretty-printing of unicode strings'
          encoding = locale.getpreferredencoding()
          def check_repr(text):
              try:
                  text.encode(encoding)
                  printable = True
              except UnicodeEncodeError:
                  self.assertGdbRepr(text, ascii(text))
              else:
                  self.assertGdbRepr(text)
  
          self.assertGdbRepr('')
          self.assertGdbRepr('And now for something hopefully the same')
          self.assertGdbRepr('string with embedded NUL here \0 and then some more text')
  
          # Test printing a single character:
          #    U+2620 SKULL AND CROSSBONES
          check_repr('\u2620')
  
          # Test printing a Japanese unicode string
          # (I believe this reads "mojibake", using 3 characters from the CJK
          # Unified Ideographs area, followed by U+3051 HIRAGANA LETTER KE)
          check_repr('\u6587\u5b57\u5316\u3051')
  
          # Test a character outside the BMP:
          #    U+1D121 MUSICAL SYMBOL C CLEF
          # This is:
          # UTF-8: 0xF0 0x9D 0x84 0xA1
          # UTF-16: 0xD834 0xDD21
          check_repr(chr(0x1D121))
  
      def test_tuples(self):
          'Verify the pretty-printing of tuples'
          self.assertGdbRepr(tuple(), '()')
          self.assertGdbRepr((1,), '(1,)')
          self.assertGdbRepr(('foo', 'bar', 'baz'))
  
      def test_sets(self):
          'Verify the pretty-printing of sets'
          if (gdb_major_version, gdb_minor_version) < (7, 3):
              self.skipTest("pretty-printing of sets needs gdb 7.3 or later")
          self.assertGdbRepr(set(), 'set()')
          self.assertGdbRepr(set(['a', 'b']), "{'a', 'b'}")
          self.assertGdbRepr(set([4, 5, 6]), "{4, 5, 6}")
  
          # Ensure that we handle sets containing the "dummy" key value,
          # which happens on deletion:
          gdb_repr, gdb_output = self.get_gdb_repr('''s = set(['a','b'])
  s.remove('a')
  id(s)''')
          self.assertEqual(gdb_repr, "{'b'}")
  
      def test_frozensets(self):
          'Verify the pretty-printing of frozensets'
          if (gdb_major_version, gdb_minor_version) < (7, 3):
              self.skipTest("pretty-printing of frozensets needs gdb 7.3 or later")
          self.assertGdbRepr(frozenset(), 'frozenset()')
          self.assertGdbRepr(frozenset(['a', 'b']), "frozenset({'a', 'b'})")
          self.assertGdbRepr(frozenset([4, 5, 6]), "frozenset({4, 5, 6})")
  
      def test_exceptions(self):
          # Test a RuntimeError
          gdb_repr, gdb_output = self.get_gdb_repr('''
  try:
      raise RuntimeError("I am an error")
  except RuntimeError as e:
      id(e)
  ''')
          self.assertEqual(gdb_repr,
                           "RuntimeError('I am an error',)")
  
  
          # Test division by zero:
          gdb_repr, gdb_output = self.get_gdb_repr('''
  try:
      a = 1 / 0
  except ZeroDivisionError as e:
      id(e)
  ''')
          self.assertEqual(gdb_repr,
                           "ZeroDivisionError('division by zero',)")
  
      def test_modern_class(self):
          'Verify the pretty-printing of new-style class instances'
          gdb_repr, gdb_output = self.get_gdb_repr('''
  class Foo:
      pass
  foo = Foo()
  foo.an_int = 42
  id(foo)''')
          m = re.match(r'<Foo\(an_int=42\) at remote 0x-?[0-9a-f]+>', gdb_repr)
          self.assertTrue(m,
                          msg='Unexpected new-style class rendering %r' % gdb_repr)
  
      def test_subclassing_list(self):
          'Verify the pretty-printing of an instance of a list subclass'
          gdb_repr, gdb_output = self.get_gdb_repr('''
  class Foo(list):
      pass
  foo = Foo()
  foo += [1, 2, 3]
  foo.an_int = 42
  id(foo)''')
          m = re.match(r'<Foo\(an_int=42\) at remote 0x-?[0-9a-f]+>', gdb_repr)
  
          self.assertTrue(m,
                          msg='Unexpected new-style class rendering %r' % gdb_repr)
  
      def test_subclassing_tuple(self):
          'Verify the pretty-printing of an instance of a tuple subclass'
          # This should exercise the negative tp_dictoffset code in the
          # new-style class support
          gdb_repr, gdb_output = self.get_gdb_repr('''
  class Foo(tuple):
      pass
  foo = Foo((1, 2, 3))
  foo.an_int = 42
  id(foo)''')
          m = re.match(r'<Foo\(an_int=42\) at remote 0x-?[0-9a-f]+>', gdb_repr)
  
          self.assertTrue(m,
                          msg='Unexpected new-style class rendering %r' % gdb_repr)
  
      def assertSane(self, source, corruption, exprepr=None):
          '''Run Python under gdb, corrupting variables in the inferior process
          immediately before taking a backtrace.
  
          Verify that the variable's representation is the expected failsafe
          representation'''
          if corruption:
              cmds_after_breakpoint=[corruption, 'backtrace']
          else:
              cmds_after_breakpoint=['backtrace']
  
          gdb_repr, gdb_output = \
              self.get_gdb_repr(source,
                                cmds_after_breakpoint=cmds_after_breakpoint)
          if exprepr:
              if gdb_repr == exprepr:
                  # gdb managed to print the value in spite of the corruption;
                  # this is good (see http://bugs.python.org/issue8330)
                  return
  
          # Match anything for the type name; 0xDEADBEEF could point to
          # something arbitrary (see  http://bugs.python.org/issue8330)
          pattern = '<.* at remote 0x-?[0-9a-f]+>'
  
          m = re.match(pattern, gdb_repr)
          if not m:
              self.fail('Unexpected gdb representation: %r\n%s' % \
                            (gdb_repr, gdb_output))
  
      def test_NULL_ptr(self):
          'Ensure that a NULL PyObject* is handled gracefully'
          gdb_repr, gdb_output = (
              self.get_gdb_repr('id(42)',
                                cmds_after_breakpoint=['set variable v=0',
                                                       'backtrace'])
              )
  
          self.assertEqual(gdb_repr, '0x0')
  
      def test_NULL_ob_type(self):
          'Ensure that a PyObject* with NULL ob_type is handled gracefully'
          self.assertSane('id(42)',
                          'set v->ob_type=0')
  
      def test_corrupt_ob_type(self):
          'Ensure that a PyObject* with a corrupt ob_type is handled gracefully'
          self.assertSane('id(42)',
                          'set v->ob_type=0xDEADBEEF',
                          exprepr='42')
  
      def test_corrupt_tp_flags(self):
          'Ensure that a PyObject* with a type with corrupt tp_flags is handled'
          self.assertSane('id(42)',
                          'set v->ob_type->tp_flags=0x0',
                          exprepr='42')
  
      def test_corrupt_tp_name(self):
          'Ensure that a PyObject* with a type with corrupt tp_name is handled'
          self.assertSane('id(42)',
                          'set v->ob_type->tp_name=0xDEADBEEF',
                          exprepr='42')
  
      def test_builtins_help(self):
          'Ensure that the new-style class _Helper in site.py can be handled'
          # (this was the issue causing tracebacks in
          #  http://bugs.python.org/issue8032#msg100537 )
          gdb_repr, gdb_output = self.get_gdb_repr('id(__builtins__.help)', import_site=True)
  
          m = re.match(r'<_Helper at remote 0x-?[0-9a-f]+>', gdb_repr)
          self.assertTrue(m,
                          msg='Unexpected rendering %r' % gdb_repr)
  
      def test_selfreferential_list(self):
          '''Ensure that a reference loop involving a list doesn't lead proxyval
          into an infinite loop:'''
          gdb_repr, gdb_output = \
              self.get_gdb_repr("a = [3, 4, 5] ; a.append(a) ; id(a)")
          self.assertEqual(gdb_repr, '[3, 4, 5, [...]]')
  
          gdb_repr, gdb_output = \
              self.get_gdb_repr("a = [3, 4, 5] ; b = [a] ; a.append(b) ; id(a)")
          self.assertEqual(gdb_repr, '[3, 4, 5, [[...]]]')
  
      def test_selfreferential_dict(self):
          '''Ensure that a reference loop involving a dict doesn't lead proxyval
          into an infinite loop:'''
          gdb_repr, gdb_output = \
              self.get_gdb_repr("a = {} ; b = {'bar':a} ; a['foo'] = b ; id(a)")
  
          self.assertEqual(gdb_repr, "{'foo': {'bar': {...}}}")
  
      def test_selfreferential_old_style_instance(self):
          gdb_repr, gdb_output = \
              self.get_gdb_repr('''
  class Foo:
      pass
  foo = Foo()
  foo.an_attr = foo
  id(foo)''')
          self.assertTrue(re.match('<Foo\(an_attr=<\.\.\.>\) at remote 0x-?[0-9a-f]+>',
                                   gdb_repr),
                          'Unexpected gdb representation: %r\n%s' % \
                              (gdb_repr, gdb_output))
  
      def test_selfreferential_new_style_instance(self):
          gdb_repr, gdb_output = \
              self.get_gdb_repr('''
  class Foo(object):
      pass
  foo = Foo()
  foo.an_attr = foo
  id(foo)''')
          self.assertTrue(re.match('<Foo\(an_attr=<\.\.\.>\) at remote 0x-?[0-9a-f]+>',
                                   gdb_repr),
                          'Unexpected gdb representation: %r\n%s' % \
                              (gdb_repr, gdb_output))
  
          gdb_repr, gdb_output = \
              self.get_gdb_repr('''
  class Foo(object):
      pass
  a = Foo()
  b = Foo()
  a.an_attr = b
  b.an_attr = a
  id(a)''')
          self.assertTrue(re.match('<Foo\(an_attr=<Foo\(an_attr=<\.\.\.>\) at remote 0x-?[0-9a-f]+>\) at remote 0x-?[0-9a-f]+>',
                                   gdb_repr),
                          'Unexpected gdb representation: %r\n%s' % \
                              (gdb_repr, gdb_output))
  
      def test_truncation(self):
          'Verify that very long output is truncated'
          gdb_repr, gdb_output = self.get_gdb_repr('id(list(range(1000)))')
          self.assertEqual(gdb_repr,
                           "[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, "
                           "14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, "
                           "27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, "
                           "40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, "
                           "53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, "
                           "66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, "
                           "79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, "
                           "92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, "
                           "104, 105, 106, 107, 108, 109, 110, 111, 112, 113, "
                           "114, 115, 116, 117, 118, 119, 120, 121, 122, 123, "
                           "124, 125, 126, 127, 128, 129, 130, 131, 132, 133, "
                           "134, 135, 136, 137, 138, 139, 140, 141, 142, 143, "
                           "144, 145, 146, 147, 148, 149, 150, 151, 152, 153, "
                           "154, 155, 156, 157, 158, 159, 160, 161, 162, 163, "
                           "164, 165, 166, 167, 168, 169, 170, 171, 172, 173, "
                           "174, 175, 176, 177, 178, 179, 180, 181, 182, 183, "
                           "184, 185, 186, 187, 188, 189, 190, 191, 192, 193, "
                           "194, 195, 196, 197, 198, 199, 200, 201, 202, 203, "
                           "204, 205, 206, 207, 208, 209, 210, 211, 212, 213, "
                           "214, 215, 216, 217, 218, 219, 220, 221, 222, 223, "
                           "224, 225, 226...(truncated)")
          self.assertEqual(len(gdb_repr),
                           1024 + len('...(truncated)'))
  
      def test_builtin_method(self):
          gdb_repr, gdb_output = self.get_gdb_repr('import sys; id(sys.stdout.readlines)')
          self.assertTrue(re.match('<built-in method readlines of _io.TextIOWrapper object at remote 0x-?[0-9a-f]+>',
                                   gdb_repr),
                          'Unexpected gdb representation: %r\n%s' % \
                              (gdb_repr, gdb_output))
  
      def test_frames(self):
          gdb_output = self.get_stack_trace('''
  def foo(a, b, c):
      pass
  
  foo(3, 4, 5)
  id(foo.__code__)''',
                                            breakpoint='builtin_id',
                                            cmds_after_breakpoint=['print (PyFrameObject*)(((PyCodeObject*)v)->co_zombieframe)']
                                            )
          self.assertTrue(re.match('.*\s+\$1 =\s+Frame 0x-?[0-9a-f]+, for file <string>, line 3, in foo \(\)\s+.*',
                                   gdb_output,
                                   re.DOTALL),
                          'Unexpected gdb representation: %r\n%s' % (gdb_output, gdb_output))
  
  @unittest.skipIf(python_is_optimized(),
                   "Python was compiled with optimizations")
  class PyListTests(DebuggerTests):
      def assertListing(self, expected, actual):
          self.assertEndsWith(actual, expected)
  
      def test_basic_command(self):
          'Verify that the "py-list" command works'
          bt = self.get_stack_trace(script=self.get_sample_script(),
                                    cmds_after_breakpoint=['py-list'])
  
          self.assertListing('   5    \n'
                             '   6    def bar(a, b, c):\n'
                             '   7        baz(a, b, c)\n'
                             '   8    \n'
                             '   9    def baz(*args):\n'
                             ' >10        id(42)\n'
                             '  11    \n'
                             '  12    foo(1, 2, 3)\n',
                             bt)
  
      def test_one_abs_arg(self):
          'Verify the "py-list" command with one absolute argument'
          bt = self.get_stack_trace(script=self.get_sample_script(),
                                    cmds_after_breakpoint=['py-list 9'])
  
          self.assertListing('   9    def baz(*args):\n'
                             ' >10        id(42)\n'
                             '  11    \n'
                             '  12    foo(1, 2, 3)\n',
                             bt)
  
      def test_two_abs_args(self):
          'Verify the "py-list" command with two absolute arguments'
          bt = self.get_stack_trace(script=self.get_sample_script(),
                                    cmds_after_breakpoint=['py-list 1,3'])
  
          self.assertListing('   1    # Sample script for use by test_gdb.py\n'
                             '   2    \n'
                             '   3    def foo(a, b, c):\n',
                             bt)
  
  class StackNavigationTests(DebuggerTests):
      @unittest.skipUnless(HAS_PYUP_PYDOWN, "test requires py-up/py-down commands")
      @unittest.skipIf(python_is_optimized(),
                       "Python was compiled with optimizations")
      def test_pyup_command(self):
          'Verify that the "py-up" command works'
          bt = self.get_stack_trace(script=self.get_sample_script(),
                                    cmds_after_breakpoint=['py-up'])
          self.assertMultilineMatches(bt,
                                      r'''^.*
  #[0-9]+ Frame 0x-?[0-9a-f]+, for file .*gdb_sample.py, line 7, in bar \(a=1, b=2, c=3\)
      baz\(a, b, c\)
  $''')
  
      @unittest.skipUnless(HAS_PYUP_PYDOWN, "test requires py-up/py-down commands")
      def test_down_at_bottom(self):
          'Verify handling of "py-down" at the bottom of the stack'
          bt = self.get_stack_trace(script=self.get_sample_script(),
                                    cmds_after_breakpoint=['py-down'])
          self.assertEndsWith(bt,
                              'Unable to find a newer python frame\n')
  
      @unittest.skipUnless(HAS_PYUP_PYDOWN, "test requires py-up/py-down commands")
      def test_up_at_top(self):
          'Verify handling of "py-up" at the top of the stack'
          bt = self.get_stack_trace(script=self.get_sample_script(),
                                    cmds_after_breakpoint=['py-up'] * 4)
          self.assertEndsWith(bt,
                              'Unable to find an older python frame\n')
  
      @unittest.skipUnless(HAS_PYUP_PYDOWN, "test requires py-up/py-down commands")
      @unittest.skipIf(python_is_optimized(),
                       "Python was compiled with optimizations")
      def test_up_then_down(self):
          'Verify "py-up" followed by "py-down"'
          bt = self.get_stack_trace(script=self.get_sample_script(),
                                    cmds_after_breakpoint=['py-up', 'py-down'])
          self.assertMultilineMatches(bt,
                                      r'''^.*
  #[0-9]+ Frame 0x-?[0-9a-f]+, for file .*gdb_sample.py, line 7, in bar \(a=1, b=2, c=3\)
      baz\(a, b, c\)
  #[0-9]+ Frame 0x-?[0-9a-f]+, for file .*gdb_sample.py, line 10, in baz \(args=\(1, 2, 3\)\)
      id\(42\)
  $''')
  
  class PyBtTests(DebuggerTests):
      @unittest.skipIf(python_is_optimized(),
                       "Python was compiled with optimizations")
      def test_bt(self):
          'Verify that the "py-bt" command works'
          bt = self.get_stack_trace(script=self.get_sample_script(),
                                    cmds_after_breakpoint=['py-bt'])
          self.assertMultilineMatches(bt,
                                      r'''^.*
  Traceback \(most recent call first\):
    File ".*gdb_sample.py", line 10, in baz
      id\(42\)
    File ".*gdb_sample.py", line 7, in bar
      baz\(a, b, c\)
    File ".*gdb_sample.py", line 4, in foo
      bar\(a, b, c\)
    File ".*gdb_sample.py", line 12, in <module>
      foo\(1, 2, 3\)
  ''')
  
      @unittest.skipIf(python_is_optimized(),
                       "Python was compiled with optimizations")
      def test_bt_full(self):
          'Verify that the "py-bt-full" command works'
          bt = self.get_stack_trace(script=self.get_sample_script(),
                                    cmds_after_breakpoint=['py-bt-full'])
          self.assertMultilineMatches(bt,
                                      r'''^.*
  #[0-9]+ Frame 0x-?[0-9a-f]+, for file .*gdb_sample.py, line 7, in bar \(a=1, b=2, c=3\)
      baz\(a, b, c\)
  #[0-9]+ Frame 0x-?[0-9a-f]+, for file .*gdb_sample.py, line 4, in foo \(a=1, b=2, c=3\)
      bar\(a, b, c\)
  #[0-9]+ Frame 0x-?[0-9a-f]+, for file .*gdb_sample.py, line 12, in <module> \(\)
      foo\(1, 2, 3\)
  ''')
  
      @unittest.skipUnless(_thread,
                           "Python was compiled without thread support")
      def test_threads(self):
          'Verify that "py-bt" indicates threads that are waiting for the GIL'
          cmd = '''
  from threading import Thread
  
  class TestThread(Thread):
      # These threads would run forever, but we'll interrupt things with the
      # debugger
      def run(self):
          i = 0
          while 1:
               i += 1
  
  t = {}
  for i in range(4):
     t[i] = TestThread()
     t[i].start()
  
  # Trigger a breakpoint on the main thread
  id(42)
  
  '''
          # Verify with "py-bt":
          gdb_output = self.get_stack_trace(cmd,
                                            cmds_after_breakpoint=['thread apply all py-bt'])
          self.assertIn('Waiting for the GIL', gdb_output)
  
          # Verify with "py-bt-full":
          gdb_output = self.get_stack_trace(cmd,
                                            cmds_after_breakpoint=['thread apply all py-bt-full'])
          self.assertIn('Waiting for the GIL', gdb_output)
  
      @unittest.skipIf(python_is_optimized(),
                       "Python was compiled with optimizations")
      # Some older versions of gdb will fail with
      #  "Cannot find new threads: generic error"
      # unless we add LD_PRELOAD=PATH-TO-libpthread.so.1 as a workaround
      @unittest.skipUnless(_thread,
                           "Python was compiled without thread support")
      def test_gc(self):
          'Verify that "py-bt" indicates if a thread is garbage-collecting'
          cmd = ('from gc import collect\n'
                 'id(42)\n'
                 'def foo():\n'
                 '    collect()\n'
                 'def bar():\n'
                 '    foo()\n'
                 'bar()\n')
          # Verify with "py-bt":
          gdb_output = self.get_stack_trace(cmd,
                                            cmds_after_breakpoint=['break update_refs', 'continue', 'py-bt'],
                                            )
          self.assertIn('Garbage-collecting', gdb_output)
  
          # Verify with "py-bt-full":
          gdb_output = self.get_stack_trace(cmd,
                                            cmds_after_breakpoint=['break update_refs', 'continue', 'py-bt-full'],
                                            )
          self.assertIn('Garbage-collecting', gdb_output)
  
      @unittest.skipIf(python_is_optimized(),
                       "Python was compiled with optimizations")
      # Some older versions of gdb will fail with
      #  "Cannot find new threads: generic error"
      # unless we add LD_PRELOAD=PATH-TO-libpthread.so.1 as a workaround
      @unittest.skipUnless(_thread,
                           "Python was compiled without thread support")
      def test_pycfunction(self):
          'Verify that "py-bt" displays invocations of PyCFunction instances'
          # Tested function must not be defined with METH_NOARGS or METH_O,
          # otherwise call_function() doesn't call PyCFunction_Call()
          cmd = ('from time import gmtime\n'
                 'def foo():\n'
                 '    gmtime(1)\n'
                 'def bar():\n'
                 '    foo()\n'
                 'bar()\n')
          # Verify with "py-bt":
          gdb_output = self.get_stack_trace(cmd,
                                            breakpoint='time_gmtime',
                                            cmds_after_breakpoint=['bt', 'py-bt'],
                                            )
          self.assertIn('<built-in method gmtime', gdb_output)
  
          # Verify with "py-bt-full":
          gdb_output = self.get_stack_trace(cmd,
                                            breakpoint='time_gmtime',
                                            cmds_after_breakpoint=['py-bt-full'],
                                            )
          self.assertIn('#0 <built-in method gmtime', gdb_output)
  
  
  class PyPrintTests(DebuggerTests):
      @unittest.skipIf(python_is_optimized(),
                       "Python was compiled with optimizations")
      def test_basic_command(self):
          'Verify that the "py-print" command works'
          bt = self.get_stack_trace(script=self.get_sample_script(),
                                    cmds_after_breakpoint=['py-print args'])
          self.assertMultilineMatches(bt,
                                      r".*\nlocal 'args' = \(1, 2, 3\)\n.*")
  
      @unittest.skipIf(python_is_optimized(),
                       "Python was compiled with optimizations")
      @unittest.skipUnless(HAS_PYUP_PYDOWN, "test requires py-up/py-down commands")
      def test_print_after_up(self):
          bt = self.get_stack_trace(script=self.get_sample_script(),
                                    cmds_after_breakpoint=['py-up', 'py-print c', 'py-print b', 'py-print a'])
          self.assertMultilineMatches(bt,
                                      r".*\nlocal 'c' = 3\nlocal 'b' = 2\nlocal 'a' = 1\n.*")
  
      @unittest.skipIf(python_is_optimized(),
                       "Python was compiled with optimizations")
      def test_printing_global(self):
          bt = self.get_stack_trace(script=self.get_sample_script(),
                                    cmds_after_breakpoint=['py-print __name__'])
          self.assertMultilineMatches(bt,
                                      r".*\nglobal '__name__' = '__main__'\n.*")
  
      @unittest.skipIf(python_is_optimized(),
                       "Python was compiled with optimizations")
      def test_printing_builtin(self):
          bt = self.get_stack_trace(script=self.get_sample_script(),
                                    cmds_after_breakpoint=['py-print len'])
          self.assertMultilineMatches(bt,
                                      r".*\nbuiltin 'len' = <built-in method len of module object at remote 0x-?[0-9a-f]+>\n.*")
  
  class PyLocalsTests(DebuggerTests):
      @unittest.skipIf(python_is_optimized(),
                       "Python was compiled with optimizations")
      def test_basic_command(self):
          bt = self.get_stack_trace(script=self.get_sample_script(),
                                    cmds_after_breakpoint=['py-locals'])
          self.assertMultilineMatches(bt,
                                      r".*\nargs = \(1, 2, 3\)\n.*")
  
      @unittest.skipUnless(HAS_PYUP_PYDOWN, "test requires py-up/py-down commands")
      @unittest.skipIf(python_is_optimized(),
                       "Python was compiled with optimizations")
      def test_locals_after_up(self):
          bt = self.get_stack_trace(script=self.get_sample_script(),
                                    cmds_after_breakpoint=['py-up', 'py-locals'])
          self.assertMultilineMatches(bt,
                                      r".*\na = 1\nb = 2\nc = 3\n.*")
  
  def test_main():
      if support.verbose:
          print("GDB version %s.%s:" % (gdb_major_version, gdb_minor_version))
          for line in gdb_version.splitlines():
              print(" " * 4 + line)
      run_unittest(PrettyPrintTests,
                   PyListTests,
                   StackNavigationTests,
                   PyBtTests,
                   PyPrintTests,
                   PyLocalsTests
                   )
  
  if __name__ == "__main__":
      test_main()
  