1"""
2Base class for gdb-remote test cases.
3"""
4
5from __future__ import division, print_function
6
7
8import errno
9import os
10import os.path
11import random
12import re
13import select
14import socket
15import subprocess
16import sys
17import tempfile
18import time
19from lldbsuite.test import configuration
20from lldbsuite.test.lldbtest import *
21from lldbsuite.support import seven
22from lldbgdbserverutils import *
23import logging
24
25
26class _ConnectionRefused(IOError):
27    pass
28
29
30class GdbRemoteTestCaseFactory(type):
31
32    def __new__(cls, name, bases, attrs):
33        newattrs = {}
34        for attrname, attrvalue in attrs.items():
35            if not attrname.startswith("test"):
36                newattrs[attrname] = attrvalue
37                continue
38
39            # If any debug server categories were explicitly tagged, assume
40            # that list to be authoritative. If none were specified, try
41            # all of them.
42            all_categories = set(["debugserver", "llgs"])
43            categories = set(
44                getattr(attrvalue, "categories", [])) & all_categories
45            if not categories:
46                categories = all_categories
47
48            for cat in categories:
49                @decorators.add_test_categories([cat])
50                @wraps(attrvalue)
51                def test_method(self, attrvalue=attrvalue):
52                    return attrvalue(self)
53
54                method_name = attrname + "_" + cat
55                test_method.__name__ = method_name
56                test_method.debug_server = cat
57                newattrs[method_name] = test_method
58
59        return super(GdbRemoteTestCaseFactory, cls).__new__(
60                cls, name, bases, newattrs)
61
62@add_metaclass(GdbRemoteTestCaseFactory)
63class GdbRemoteTestCaseBase(Base):
64
65    # Default time out in seconds. The timeout is increased tenfold under Asan.
66    DEFAULT_TIMEOUT =  20 * (10 if ('ASAN_OPTIONS' in os.environ) else 1)
67    # Default sleep time in seconds. The sleep time is doubled under Asan.
68    DEFAULT_SLEEP   =  5  * (2  if ('ASAN_OPTIONS' in os.environ) else 1)
69
70    _GDBREMOTE_KILL_PACKET = b"$k#6b"
71
72    # Start the inferior separately, attach to the inferior on the stub
73    # command line.
74    _STARTUP_ATTACH = "attach"
75    # Start the inferior separately, start the stub without attaching, allow
76    # the test to attach to the inferior however it wants (e.g. $vAttach;pid).
77    _STARTUP_ATTACH_MANUALLY = "attach_manually"
78    # Start the stub, and launch the inferior with an $A packet via the
79    # initial packet stream.
80    _STARTUP_LAUNCH = "launch"
81
82    # GDB Signal numbers that are not target-specific used for common
83    # exceptions
84    TARGET_EXC_BAD_ACCESS = 0x91
85    TARGET_EXC_BAD_INSTRUCTION = 0x92
86    TARGET_EXC_ARITHMETIC = 0x93
87    TARGET_EXC_EMULATION = 0x94
88    TARGET_EXC_SOFTWARE = 0x95
89    TARGET_EXC_BREAKPOINT = 0x96
90
91    _verbose_log_handler = None
92    _log_formatter = logging.Formatter(
93        fmt='%(asctime)-15s %(levelname)-8s %(message)s')
94
95    def setUpBaseLogging(self):
96        self.logger = logging.getLogger(__name__)
97
98        if len(self.logger.handlers) > 0:
99            return  # We have set up this handler already
100
101        self.logger.propagate = False
102        self.logger.setLevel(logging.DEBUG)
103
104        # log all warnings to stderr
105        handler = logging.StreamHandler()
106        handler.setLevel(logging.WARNING)
107        handler.setFormatter(self._log_formatter)
108        self.logger.addHandler(handler)
109
110    def isVerboseLoggingRequested(self):
111        # We will report our detailed logs if the user requested that the "gdb-remote" channel is
112        # logged.
113        return any(("gdb-remote" in channel)
114                   for channel in lldbtest_config.channels)
115
116    def getDebugServer(self):
117        method = getattr(self, self.testMethodName)
118        return getattr(method, "debug_server", None)
119
120    def setUp(self):
121        super(GdbRemoteTestCaseBase, self).setUp()
122
123        self.setUpBaseLogging()
124        self.debug_monitor_extra_args = []
125
126        if self.isVerboseLoggingRequested():
127            # If requested, full logs go to a log file
128            self._verbose_log_handler = logging.FileHandler(
129                self.getLogBasenameForCurrentTest() + "-host.log")
130            self._verbose_log_handler.setFormatter(self._log_formatter)
131            self._verbose_log_handler.setLevel(logging.DEBUG)
132            self.logger.addHandler(self._verbose_log_handler)
133
134        self.test_sequence = GdbRemoteTestSequence(self.logger)
135        self.set_inferior_startup_launch()
136        self.port = self.get_next_port()
137        self.stub_sends_two_stop_notifications_on_kill = False
138        if configuration.lldb_platform_url:
139            if configuration.lldb_platform_url.startswith('unix-'):
140                url_pattern = '(.+)://\[?(.+?)\]?/.*'
141            else:
142                url_pattern = '(.+)://(.+):\d+'
143            scheme, host = re.match(
144                url_pattern, configuration.lldb_platform_url).groups()
145            if configuration.lldb_platform_name == 'remote-android' and host != 'localhost':
146                self.stub_device = host
147                self.stub_hostname = 'localhost'
148            else:
149                self.stub_device = None
150                self.stub_hostname = host
151        else:
152            self.stub_hostname = "localhost"
153
154        debug_server = self.getDebugServer()
155        if debug_server == "debugserver":
156            self._init_debugserver_test()
157        else:
158            self._init_llgs_test()
159
160    def tearDown(self):
161        self.logger.removeHandler(self._verbose_log_handler)
162        self._verbose_log_handler = None
163        TestBase.tearDown(self)
164
165    def build(self, *args, **kwargs):
166        self.buildDefault(*args, **kwargs)
167
168    def getLocalServerLogFile(self):
169        return self.getLogBasenameForCurrentTest() + "-server.log"
170
171    def setUpServerLogging(self, is_llgs):
172        if len(lldbtest_config.channels) == 0:
173            return  # No logging requested
174
175        if lldb.remote_platform:
176            log_file = lldbutil.join_remote_paths(
177                lldb.remote_platform.GetWorkingDirectory(), "server.log")
178        else:
179            log_file = self.getLocalServerLogFile()
180
181        if is_llgs:
182            self.debug_monitor_extra_args.append("--log-file=" + log_file)
183            self.debug_monitor_extra_args.append(
184                "--log-channels={}".format(":".join(lldbtest_config.channels)))
185        else:
186            self.debug_monitor_extra_args = [
187                "--log-file=" + log_file, "--log-flags=0x800000"]
188
189    def get_next_port(self):
190        return 12000 + random.randint(0, 3999)
191
192    def reset_test_sequence(self):
193        self.test_sequence = GdbRemoteTestSequence(self.logger)
194
195
196    def _init_llgs_test(self):
197        reverse_connect = True
198        if lldb.remote_platform:
199            # Reverse connections may be tricky due to firewalls/NATs.
200            reverse_connect = False
201
202            # FIXME: This is extremely linux-oriented
203
204            # Grab the ppid from /proc/[shell pid]/stat
205            err, retcode, shell_stat = self.run_platform_command(
206                "cat /proc/$$/stat")
207            self.assertTrue(
208                err.Success() and retcode == 0,
209                "Failed to read file /proc/$$/stat: %s, retcode: %d" %
210                (err.GetCString(),
211                 retcode))
212
213            # [pid] ([executable]) [state] [*ppid*]
214            pid = re.match(r"^\d+ \(.+\) . (\d+)", shell_stat).group(1)
215            err, retcode, ls_output = self.run_platform_command(
216                "ls -l /proc/%s/exe" % pid)
217            self.assertTrue(
218                err.Success() and retcode == 0,
219                "Failed to read file /proc/%s/exe: %s, retcode: %d" %
220                (pid,
221                 err.GetCString(),
222                 retcode))
223            exe = ls_output.split()[-1]
224
225            # If the binary has been deleted, the link name has " (deleted)" appended.
226            # Remove if it's there.
227            self.debug_monitor_exe = re.sub(r' \(deleted\)$', '', exe)
228        else:
229            self.debug_monitor_exe = get_lldb_server_exe()
230
231        self.debug_monitor_extra_args = ["gdbserver"]
232        self.setUpServerLogging(is_llgs=True)
233
234        self.reverse_connect = reverse_connect
235
236    def _init_debugserver_test(self):
237        self.debug_monitor_exe = get_debugserver_exe()
238        self.setUpServerLogging(is_llgs=False)
239        self.reverse_connect = True
240
241        # The debugserver stub has a race on handling the 'k' command, so it sends an X09 right away, then sends the real X notification
242        # when the process truly dies.
243        self.stub_sends_two_stop_notifications_on_kill = True
244
245    def forward_adb_port(self, source, target, direction, device):
246        adb = ['adb'] + (['-s', device] if device else []) + [direction]
247
248        def remove_port_forward():
249            subprocess.call(adb + ["--remove", "tcp:%d" % source])
250
251        subprocess.call(adb + ["tcp:%d" % source, "tcp:%d" % target])
252        self.addTearDownHook(remove_port_forward)
253
254    def _verify_socket(self, sock):
255        # Normally, when the remote stub is not ready, we will get ECONNREFUSED during the
256        # connect() attempt. However, due to the way how ADB forwarding works, on android targets
257        # the connect() will always be successful, but the connection will be immediately dropped
258        # if ADB could not connect on the remote side. This function tries to detect this
259        # situation, and report it as "connection refused" so that the upper layers attempt the
260        # connection again.
261        triple = self.dbg.GetSelectedPlatform().GetTriple()
262        if not re.match(".*-.*-.*-android", triple):
263            return  # Not android.
264        can_read, _, _ = select.select([sock], [], [], 0.1)
265        if sock not in can_read:
266            return  # Data is not available, but the connection is alive.
267        if len(sock.recv(1, socket.MSG_PEEK)) == 0:
268            raise _ConnectionRefused()  # Got EOF, connection dropped.
269
270    def create_socket(self):
271        try:
272            sock = socket.socket(family=socket.AF_INET)
273        except OSError as e:
274            if e.errno != errno.EAFNOSUPPORT:
275                raise
276            sock = socket.socket(family=socket.AF_INET6)
277
278        logger = self.logger
279
280        triple = self.dbg.GetSelectedPlatform().GetTriple()
281        if re.match(".*-.*-.*-android", triple):
282            self.forward_adb_port(
283                self.port,
284                self.port,
285                "forward",
286                self.stub_device)
287
288        logger.info(
289            "Connecting to debug monitor on %s:%d",
290            self.stub_hostname,
291            self.port)
292        connect_info = (self.stub_hostname, self.port)
293        try:
294            sock.connect(connect_info)
295        except socket.error as serr:
296            if serr.errno == errno.ECONNREFUSED:
297                raise _ConnectionRefused()
298            raise serr
299
300        def shutdown_socket():
301            if sock:
302                try:
303                    # send the kill packet so lldb-server shuts down gracefully
304                    sock.sendall(GdbRemoteTestCaseBase._GDBREMOTE_KILL_PACKET)
305                except:
306                    logger.warning(
307                        "failed to send kill packet to debug monitor: {}; ignoring".format(
308                            sys.exc_info()[0]))
309
310                try:
311                    sock.close()
312                except:
313                    logger.warning(
314                        "failed to close socket to debug monitor: {}; ignoring".format(
315                            sys.exc_info()[0]))
316
317        self.addTearDownHook(shutdown_socket)
318
319        self._verify_socket(sock)
320
321        return sock
322
323    def set_inferior_startup_launch(self):
324        self._inferior_startup = self._STARTUP_LAUNCH
325
326    def set_inferior_startup_attach(self):
327        self._inferior_startup = self._STARTUP_ATTACH
328
329    def set_inferior_startup_attach_manually(self):
330        self._inferior_startup = self._STARTUP_ATTACH_MANUALLY
331
332    def get_debug_monitor_command_line_args(self, attach_pid=None):
333        commandline_args = self.debug_monitor_extra_args
334        if attach_pid:
335            commandline_args += ["--attach=%d" % attach_pid]
336        if self.reverse_connect:
337            commandline_args += ["--reverse-connect", self.connect_address]
338        else:
339            if lldb.remote_platform:
340                commandline_args += ["*:{}".format(self.port)]
341            else:
342                commandline_args += ["localhost:{}".format(self.port)]
343
344        return commandline_args
345
346    def get_target_byte_order(self):
347        inferior_exe_path = self.getBuildArtifact("a.out")
348        target = self.dbg.CreateTarget(inferior_exe_path)
349        return target.GetByteOrder()
350
351    def launch_debug_monitor(self, attach_pid=None, logfile=None):
352        if self.reverse_connect:
353            family, type, proto, _, addr = socket.getaddrinfo("localhost", 0, proto=socket.IPPROTO_TCP)[0]
354            sock = socket.socket(family, type, proto)
355            sock.settimeout(self.DEFAULT_TIMEOUT)
356
357            sock.bind(addr)
358            sock.listen(1)
359            addr = sock.getsockname()
360            self.connect_address = "[{}]:{}".format(*addr)
361
362
363        # Create the command line.
364        commandline_args = self.get_debug_monitor_command_line_args(
365            attach_pid=attach_pid)
366
367        # Start the server.
368        server = self.spawnSubprocess(
369            self.debug_monitor_exe,
370            commandline_args,
371            install_remote=False)
372        self.assertIsNotNone(server)
373
374        if self.reverse_connect:
375            self.sock = sock.accept()[0]
376            self.sock.settimeout(self.DEFAULT_TIMEOUT)
377
378        return server
379
380    def connect_to_debug_monitor(self, attach_pid=None):
381        if self.reverse_connect:
382            # Create the stub.
383            server = self.launch_debug_monitor(attach_pid=attach_pid)
384            self.assertIsNotNone(server)
385
386            # Schedule debug monitor to be shut down during teardown.
387            logger = self.logger
388
389            self._server = Server(self.sock, server)
390            return server
391
392        # We're using a random port algorithm to try not to collide with other ports,
393        # and retry a max # times.
394        attempts = 0
395        MAX_ATTEMPTS = 20
396
397        while attempts < MAX_ATTEMPTS:
398            server = self.launch_debug_monitor(attach_pid=attach_pid)
399
400            # Schedule debug monitor to be shut down during teardown.
401            logger = self.logger
402
403            connect_attemps = 0
404            MAX_CONNECT_ATTEMPTS = 10
405
406            while connect_attemps < MAX_CONNECT_ATTEMPTS:
407                # Create a socket to talk to the server
408                try:
409                    logger.info("Connect attempt %d", connect_attemps + 1)
410                    self.sock = self.create_socket()
411                    self._server = Server(self.sock, server)
412                    return server
413                except _ConnectionRefused as serr:
414                    # Ignore, and try again.
415                    pass
416                time.sleep(0.5)
417                connect_attemps += 1
418
419            # We should close the server here to be safe.
420            server.terminate()
421
422            # Increment attempts.
423            print(
424                "connect to debug monitor on port %d failed, attempt #%d of %d" %
425                (self.port, attempts + 1, MAX_ATTEMPTS))
426            attempts += 1
427
428            # And wait a random length of time before next attempt, to avoid
429            # collisions.
430            time.sleep(random.randint(1, 5))
431
432            # Now grab a new port number.
433            self.port = self.get_next_port()
434
435        raise Exception(
436            "failed to create a socket to the launched debug monitor after %d tries" %
437            attempts)
438
439    def launch_process_for_attach(
440            self,
441            inferior_args=None,
442            sleep_seconds=3,
443            exe_path=None):
444        # We're going to start a child process that the debug monitor stub can later attach to.
445        # This process needs to be started so that it just hangs around for a while.  We'll
446        # have it sleep.
447        if not exe_path:
448            exe_path = self.getBuildArtifact("a.out")
449
450        args = []
451        if inferior_args:
452            args.extend(inferior_args)
453        if sleep_seconds:
454            args.append("sleep:%d" % sleep_seconds)
455
456        return self.spawnSubprocess(exe_path, args)
457
458    def prep_debug_monitor_and_inferior(
459            self,
460            inferior_args=None,
461            inferior_sleep_seconds=3,
462            inferior_exe_path=None,
463            inferior_env=None):
464        """Prep the debug monitor, the inferior, and the expected packet stream.
465
466        Handle the separate cases of using the debug monitor in attach-to-inferior mode
467        and in launch-inferior mode.
468
469        For attach-to-inferior mode, the inferior process is first started, then
470        the debug monitor is started in attach to pid mode (using --attach on the
471        stub command line), and the no-ack-mode setup is appended to the packet
472        stream.  The packet stream is not yet executed, ready to have more expected
473        packet entries added to it.
474
475        For launch-inferior mode, the stub is first started, then no ack mode is
476        setup on the expected packet stream, then the verified launch packets are added
477        to the expected socket stream.  The packet stream is not yet executed, ready
478        to have more expected packet entries added to it.
479
480        The return value is:
481        {inferior:<inferior>, server:<server>}
482        """
483        inferior = None
484        attach_pid = None
485
486        if self._inferior_startup == self._STARTUP_ATTACH or self._inferior_startup == self._STARTUP_ATTACH_MANUALLY:
487            # Launch the process that we'll use as the inferior.
488            inferior = self.launch_process_for_attach(
489                inferior_args=inferior_args,
490                sleep_seconds=inferior_sleep_seconds,
491                exe_path=inferior_exe_path)
492            self.assertIsNotNone(inferior)
493            self.assertTrue(inferior.pid > 0)
494            if self._inferior_startup == self._STARTUP_ATTACH:
495                # In this case, we want the stub to attach via the command
496                # line, so set the command line attach pid here.
497                attach_pid = inferior.pid
498
499        if self._inferior_startup == self._STARTUP_LAUNCH:
500            # Build launch args
501            if not inferior_exe_path:
502                inferior_exe_path = self.getBuildArtifact("a.out")
503
504            if lldb.remote_platform:
505                remote_path = lldbutil.append_to_process_working_directory(self,
506                    os.path.basename(inferior_exe_path))
507                remote_file_spec = lldb.SBFileSpec(remote_path, False)
508                err = lldb.remote_platform.Install(lldb.SBFileSpec(
509                    inferior_exe_path, True), remote_file_spec)
510                if err.Fail():
511                    raise Exception(
512                        "remote_platform.Install('%s', '%s') failed: %s" %
513                        (inferior_exe_path, remote_path, err))
514                inferior_exe_path = remote_path
515
516            launch_args = [inferior_exe_path]
517            if inferior_args:
518                launch_args.extend(inferior_args)
519
520        # Launch the debug monitor stub, attaching to the inferior.
521        server = self.connect_to_debug_monitor(attach_pid=attach_pid)
522        self.assertIsNotNone(server)
523
524        self.do_handshake()
525
526        # Build the expected protocol stream
527        if inferior_env:
528            for name, value in inferior_env.items():
529                self.add_set_environment_packets(name, value)
530        if self._inferior_startup == self._STARTUP_LAUNCH:
531            self.add_verified_launch_packets(launch_args)
532
533        return {"inferior": inferior, "server": server}
534
535    def do_handshake(self):
536        server = self._server
537        server.send_ack()
538        server.send_packet(b"QStartNoAckMode")
539        self.assertEqual(server.get_normal_packet(), b"+")
540        self.assertEqual(server.get_normal_packet(), b"OK")
541        server.send_ack()
542
543    def add_verified_launch_packets(self, launch_args):
544        self.test_sequence.add_log_lines(
545            ["read packet: %s" % build_gdbremote_A_packet(launch_args),
546             "send packet: $OK#00",
547             "read packet: $qLaunchSuccess#a5",
548             "send packet: $OK#00"],
549            True)
550
551    def add_thread_suffix_request_packets(self):
552        self.test_sequence.add_log_lines(
553            ["read packet: $QThreadSuffixSupported#e4",
554             "send packet: $OK#00",
555             ], True)
556
557    def add_process_info_collection_packets(self):
558        self.test_sequence.add_log_lines(
559            ["read packet: $qProcessInfo#dc",
560             {"direction": "send", "regex": r"^\$(.+)#[0-9a-fA-F]{2}$", "capture": {1: "process_info_raw"}}],
561            True)
562
563    def add_set_environment_packets(self, name, value):
564        self.test_sequence.add_log_lines(
565            ["read packet: $QEnvironment:" + name + "=" + value + "#00",
566             "send packet: $OK#00",
567             ], True)
568
569    _KNOWN_PROCESS_INFO_KEYS = [
570        "pid",
571        "parent-pid",
572        "real-uid",
573        "real-gid",
574        "effective-uid",
575        "effective-gid",
576        "cputype",
577        "cpusubtype",
578        "ostype",
579        "triple",
580        "vendor",
581        "endian",
582        "elf_abi",
583        "ptrsize"
584    ]
585
586    def parse_process_info_response(self, context):
587        # Ensure we have a process info response.
588        self.assertIsNotNone(context)
589        process_info_raw = context.get("process_info_raw")
590        self.assertIsNotNone(process_info_raw)
591
592        # Pull out key:value; pairs.
593        process_info_dict = {
594            match.group(1): match.group(2) for match in re.finditer(
595                r"([^:]+):([^;]+);", process_info_raw)}
596
597        # Validate keys are known.
598        for (key, val) in list(process_info_dict.items()):
599            self.assertTrue(key in self._KNOWN_PROCESS_INFO_KEYS)
600            self.assertIsNotNone(val)
601
602        return process_info_dict
603
604    def add_register_info_collection_packets(self):
605        self.test_sequence.add_log_lines(
606            [{"type": "multi_response", "query": "qRegisterInfo", "append_iteration_suffix": True,
607                "end_regex": re.compile(r"^\$(E\d+)?#[0-9a-fA-F]{2}$"),
608                "save_key": "reg_info_responses"}],
609            True)
610
611    def parse_register_info_packets(self, context):
612        """Return an array of register info dictionaries, one per register info."""
613        reg_info_responses = context.get("reg_info_responses")
614        self.assertIsNotNone(reg_info_responses)
615
616        # Parse register infos.
617        return [parse_reg_info_response(reg_info_response)
618                for reg_info_response in reg_info_responses]
619
620    def expect_gdbremote_sequence(self):
621        return expect_lldb_gdbserver_replay(
622            self,
623            self._server,
624            self.test_sequence,
625            self.DEFAULT_TIMEOUT * len(self.test_sequence),
626            self.logger)
627
628    _KNOWN_REGINFO_KEYS = [
629        "name",
630        "alt-name",
631        "bitsize",
632        "offset",
633        "encoding",
634        "format",
635        "set",
636        "gcc",
637        "ehframe",
638        "dwarf",
639        "generic",
640        "container-regs",
641        "invalidate-regs",
642        "dynamic_size_dwarf_expr_bytes",
643        "dynamic_size_dwarf_len"
644    ]
645
646    def assert_valid_reg_info(self, reg_info):
647        # Assert we know about all the reginfo keys parsed.
648        for key in reg_info:
649            self.assertTrue(key in self._KNOWN_REGINFO_KEYS)
650
651        # Check the bare-minimum expected set of register info keys.
652        self.assertTrue("name" in reg_info)
653        self.assertTrue("bitsize" in reg_info)
654
655        if not self.getArchitecture() == 'aarch64':
656            self.assertTrue("offset" in reg_info)
657
658        self.assertTrue("encoding" in reg_info)
659        self.assertTrue("format" in reg_info)
660
661    def find_pc_reg_info(self, reg_infos):
662        lldb_reg_index = 0
663        for reg_info in reg_infos:
664            if ("generic" in reg_info) and (reg_info["generic"] == "pc"):
665                return (lldb_reg_index, reg_info)
666            lldb_reg_index += 1
667
668        return (None, None)
669
670    def add_lldb_register_index(self, reg_infos):
671        """Add a "lldb_register_index" key containing the 0-baed index of each reg_infos entry.
672
673        We'll use this when we want to call packets like P/p with a register index but do so
674        on only a subset of the full register info set.
675        """
676        self.assertIsNotNone(reg_infos)
677
678        reg_index = 0
679        for reg_info in reg_infos:
680            reg_info["lldb_register_index"] = reg_index
681            reg_index += 1
682
683    def add_query_memory_region_packets(self, address):
684        self.test_sequence.add_log_lines(
685            ["read packet: $qMemoryRegionInfo:{0:x}#00".format(address),
686             {"direction": "send", "regex": r"^\$(.+)#[0-9a-fA-F]{2}$", "capture": {1: "memory_region_response"}}],
687            True)
688
689    def parse_key_val_dict(self, key_val_text, allow_dupes=True):
690        self.assertIsNotNone(key_val_text)
691        kv_dict = {}
692        for match in re.finditer(r";?([^:]+):([^;]+)", key_val_text):
693            key = match.group(1)
694            val = match.group(2)
695            if key in kv_dict:
696                if allow_dupes:
697                    if isinstance(kv_dict[key], list):
698                        kv_dict[key].append(val)
699                    else:
700                        # Promote to list
701                        kv_dict[key] = [kv_dict[key], val]
702                else:
703                    self.fail(
704                        "key '{}' already present when attempting to add value '{}' (text='{}', dict={})".format(
705                            key, val, key_val_text, kv_dict))
706            else:
707                kv_dict[key] = val
708        return kv_dict
709
710    def parse_memory_region_packet(self, context):
711        # Ensure we have a context.
712        self.assertIsNotNone(context.get("memory_region_response"))
713
714        # Pull out key:value; pairs.
715        mem_region_dict = self.parse_key_val_dict(
716            context.get("memory_region_response"))
717
718        # Validate keys are known.
719        for (key, val) in list(mem_region_dict.items()):
720            self.assertIn(key,
721                ["start",
722                 "size",
723                 "permissions",
724                 "flags",
725                 "name",
726                 "error"])
727            self.assertIsNotNone(val)
728
729        mem_region_dict["name"] = seven.unhexlify(mem_region_dict.get("name", ""))
730        # Return the dictionary of key-value pairs for the memory region.
731        return mem_region_dict
732
733    def assert_address_within_memory_region(
734            self, test_address, mem_region_dict):
735        self.assertIsNotNone(mem_region_dict)
736        self.assertTrue("start" in mem_region_dict)
737        self.assertTrue("size" in mem_region_dict)
738
739        range_start = int(mem_region_dict["start"], 16)
740        range_size = int(mem_region_dict["size"], 16)
741        range_end = range_start + range_size
742
743        if test_address < range_start:
744            self.fail(
745                "address 0x{0:x} comes before range 0x{1:x} - 0x{2:x} (size 0x{3:x})".format(
746                    test_address,
747                    range_start,
748                    range_end,
749                    range_size))
750        elif test_address >= range_end:
751            self.fail(
752                "address 0x{0:x} comes after range 0x{1:x} - 0x{2:x} (size 0x{3:x})".format(
753                    test_address,
754                    range_start,
755                    range_end,
756                    range_size))
757
758    def add_threadinfo_collection_packets(self):
759        self.test_sequence.add_log_lines(
760            [{"type": "multi_response", "first_query": "qfThreadInfo", "next_query": "qsThreadInfo",
761                "append_iteration_suffix": False, "end_regex": re.compile(r"^\$(l)?#[0-9a-fA-F]{2}$"),
762                "save_key": "threadinfo_responses"}],
763            True)
764
765    def parse_threadinfo_packets(self, context):
766        """Return an array of thread ids (decimal ints), one per thread."""
767        threadinfo_responses = context.get("threadinfo_responses")
768        self.assertIsNotNone(threadinfo_responses)
769
770        thread_ids = []
771        for threadinfo_response in threadinfo_responses:
772            new_thread_infos = parse_threadinfo_response(threadinfo_response)
773            thread_ids.extend(new_thread_infos)
774        return thread_ids
775
776    def wait_for_thread_count(self, thread_count):
777        start_time = time.time()
778        timeout_time = start_time + self.DEFAULT_TIMEOUT
779
780        actual_thread_count = 0
781        while actual_thread_count < thread_count:
782            self.reset_test_sequence()
783            self.add_threadinfo_collection_packets()
784
785            context = self.expect_gdbremote_sequence()
786            self.assertIsNotNone(context)
787
788            threads = self.parse_threadinfo_packets(context)
789            self.assertIsNotNone(threads)
790
791            actual_thread_count = len(threads)
792
793            if time.time() > timeout_time:
794                raise Exception(
795                    'timed out after {} seconds while waiting for theads: waiting for at least {} threads, found {}'.format(
796                        self.DEFAULT_TIMEOUT, thread_count, actual_thread_count))
797
798        return threads
799
800    def add_set_breakpoint_packets(
801            self,
802            address,
803            z_packet_type=0,
804            do_continue=True,
805            breakpoint_kind=1):
806        self.test_sequence.add_log_lines(
807            [  # Set the breakpoint.
808                "read packet: $Z{2},{0:x},{1}#00".format(
809                    address, breakpoint_kind, z_packet_type),
810                # Verify the stub could set it.
811                "send packet: $OK#00",
812            ], True)
813
814        if (do_continue):
815            self.test_sequence.add_log_lines(
816                [  # Continue the inferior.
817                    "read packet: $c#63",
818                    # Expect a breakpoint stop report.
819                    {"direction": "send",
820                     "regex": r"^\$T([0-9a-fA-F]{2})thread:([0-9a-fA-F]+);",
821                     "capture": {1: "stop_signo",
822                                 2: "stop_thread_id"}},
823                ], True)
824
825    def add_remove_breakpoint_packets(
826            self,
827            address,
828            z_packet_type=0,
829            breakpoint_kind=1):
830        self.test_sequence.add_log_lines(
831            [  # Remove the breakpoint.
832                "read packet: $z{2},{0:x},{1}#00".format(
833                    address, breakpoint_kind, z_packet_type),
834                # Verify the stub could unset it.
835                "send packet: $OK#00",
836            ], True)
837
838    def add_qSupported_packets(self):
839        self.test_sequence.add_log_lines(
840            ["read packet: $qSupported#00",
841             {"direction": "send", "regex": r"^\$(.*)#[0-9a-fA-F]{2}", "capture": {1: "qSupported_response"}},
842             ], True)
843
844    _KNOWN_QSUPPORTED_STUB_FEATURES = [
845        "augmented-libraries-svr4-read",
846        "PacketSize",
847        "QStartNoAckMode",
848        "QThreadSuffixSupported",
849        "QListThreadsInStopReply",
850        "qXfer:auxv:read",
851        "qXfer:libraries:read",
852        "qXfer:libraries-svr4:read",
853        "qXfer:features:read",
854        "qEcho",
855        "QPassSignals",
856        "multiprocess",
857    ]
858
859    def parse_qSupported_response(self, context):
860        self.assertIsNotNone(context)
861
862        raw_response = context.get("qSupported_response")
863        self.assertIsNotNone(raw_response)
864
865        # For values with key=val, the dict key and vals are set as expected.  For feature+, feature- and feature?, the
866        # +,-,? is stripped from the key and set as the value.
867        supported_dict = {}
868        for match in re.finditer(r";?([^=;]+)(=([^;]+))?", raw_response):
869            key = match.group(1)
870            val = match.group(3)
871
872            # key=val: store as is
873            if val and len(val) > 0:
874                supported_dict[key] = val
875            else:
876                if len(key) < 2:
877                    raise Exception(
878                        "singular stub feature is too short: must be stub_feature{+,-,?}")
879                supported_type = key[-1]
880                key = key[:-1]
881                if not supported_type in ["+", "-", "?"]:
882                    raise Exception(
883                        "malformed stub feature: final character {} not in expected set (+,-,?)".format(supported_type))
884                supported_dict[key] = supported_type
885            # Ensure we know the supported element
886            if key not in self._KNOWN_QSUPPORTED_STUB_FEATURES:
887                raise Exception(
888                    "unknown qSupported stub feature reported: %s" %
889                    key)
890
891        return supported_dict
892
893    def run_process_then_stop(self, run_seconds=1):
894        # Tell the stub to continue.
895        self.test_sequence.add_log_lines(
896            ["read packet: $vCont;c#a8"],
897            True)
898        context = self.expect_gdbremote_sequence()
899
900        # Wait for run_seconds.
901        time.sleep(run_seconds)
902
903        # Send an interrupt, capture a T response.
904        self.reset_test_sequence()
905        self.test_sequence.add_log_lines(
906            ["read packet: {}".format(chr(3)),
907             {"direction": "send", "regex": r"^\$T([0-9a-fA-F]+)([^#]+)#[0-9a-fA-F]{2}$", "capture": {1: "stop_result"}}],
908            True)
909        context = self.expect_gdbremote_sequence()
910        self.assertIsNotNone(context)
911        self.assertIsNotNone(context.get("stop_result"))
912
913        return context
914
915    def continue_process_and_wait_for_stop(self):
916        self.test_sequence.add_log_lines(
917            [
918                "read packet: $vCont;c#a8",
919                {
920                    "direction": "send",
921                    "regex": r"^\$T([0-9a-fA-F]{2})(.*)#[0-9a-fA-F]{2}$",
922                    "capture": {1: "stop_signo", 2: "stop_key_val_text"},
923                },
924            ],
925            True,
926        )
927        context = self.expect_gdbremote_sequence()
928        self.assertIsNotNone(context)
929        return self.parse_interrupt_packets(context)
930
931    def select_modifiable_register(self, reg_infos):
932        """Find a register that can be read/written freely."""
933        PREFERRED_REGISTER_NAMES = set(["rax", ])
934
935        # First check for the first register from the preferred register name
936        # set.
937        alternative_register_index = None
938
939        self.assertIsNotNone(reg_infos)
940        for reg_info in reg_infos:
941            if ("name" in reg_info) and (
942                    reg_info["name"] in PREFERRED_REGISTER_NAMES):
943                # We found a preferred register.  Use it.
944                return reg_info["lldb_register_index"]
945            if ("generic" in reg_info) and (reg_info["generic"] == "fp" or
946                    reg_info["generic"] == "arg1"):
947                # A frame pointer or first arg register will do as a
948                # register to modify temporarily.
949                alternative_register_index = reg_info["lldb_register_index"]
950
951        # We didn't find a preferred register.  Return whatever alternative register
952        # we found, if any.
953        return alternative_register_index
954
955    def extract_registers_from_stop_notification(self, stop_key_vals_text):
956        self.assertIsNotNone(stop_key_vals_text)
957        kv_dict = self.parse_key_val_dict(stop_key_vals_text)
958
959        registers = {}
960        for (key, val) in list(kv_dict.items()):
961            if re.match(r"^[0-9a-fA-F]+$", key):
962                registers[int(key, 16)] = val
963        return registers
964
965    def gather_register_infos(self):
966        self.reset_test_sequence()
967        self.add_register_info_collection_packets()
968
969        context = self.expect_gdbremote_sequence()
970        self.assertIsNotNone(context)
971
972        reg_infos = self.parse_register_info_packets(context)
973        self.assertIsNotNone(reg_infos)
974        self.add_lldb_register_index(reg_infos)
975
976        return reg_infos
977
978    def find_generic_register_with_name(self, reg_infos, generic_name):
979        self.assertIsNotNone(reg_infos)
980        for reg_info in reg_infos:
981            if ("generic" in reg_info) and (
982                    reg_info["generic"] == generic_name):
983                return reg_info
984        return None
985
986    def find_register_with_name_and_dwarf_regnum(self, reg_infos, name, dwarf_num):
987        self.assertIsNotNone(reg_infos)
988        for reg_info in reg_infos:
989            if (reg_info["name"] == name) and (reg_info["dwarf"] == dwarf_num):
990                return reg_info
991        return None
992
993    def decode_gdbremote_binary(self, encoded_bytes):
994        decoded_bytes = ""
995        i = 0
996        while i < len(encoded_bytes):
997            if encoded_bytes[i] == "}":
998                # Handle escaped char.
999                self.assertTrue(i + 1 < len(encoded_bytes))
1000                decoded_bytes += chr(ord(encoded_bytes[i + 1]) ^ 0x20)
1001                i += 2
1002            elif encoded_bytes[i] == "*":
1003                # Handle run length encoding.
1004                self.assertTrue(len(decoded_bytes) > 0)
1005                self.assertTrue(i + 1 < len(encoded_bytes))
1006                repeat_count = ord(encoded_bytes[i + 1]) - 29
1007                decoded_bytes += decoded_bytes[-1] * repeat_count
1008                i += 2
1009            else:
1010                decoded_bytes += encoded_bytes[i]
1011                i += 1
1012        return decoded_bytes
1013
1014    def build_auxv_dict(self, endian, word_size, auxv_data):
1015        self.assertIsNotNone(endian)
1016        self.assertIsNotNone(word_size)
1017        self.assertIsNotNone(auxv_data)
1018
1019        auxv_dict = {}
1020
1021        # PowerPC64le's auxvec has a special key that must be ignored.
1022        # This special key may be used multiple times, resulting in
1023        # multiple key/value pairs with the same key, which would otherwise
1024        # break this test check for repeated keys.
1025        #
1026        # AT_IGNOREPPC = 22
1027        ignored_keys_for_arch = { 'powerpc64le' : [22] }
1028        arch = self.getArchitecture()
1029        ignore_keys = None
1030        if arch in ignored_keys_for_arch:
1031            ignore_keys = ignored_keys_for_arch[arch]
1032
1033        while len(auxv_data) > 0:
1034            # Chop off key.
1035            raw_key = auxv_data[:word_size]
1036            auxv_data = auxv_data[word_size:]
1037
1038            # Chop of value.
1039            raw_value = auxv_data[:word_size]
1040            auxv_data = auxv_data[word_size:]
1041
1042            # Convert raw text from target endian.
1043            key = unpack_endian_binary_string(endian, raw_key)
1044            value = unpack_endian_binary_string(endian, raw_value)
1045
1046            if ignore_keys and key in ignore_keys:
1047                continue
1048
1049            # Handle ending entry.
1050            if key == 0:
1051                self.assertEqual(value, 0)
1052                return auxv_dict
1053
1054            # The key should not already be present.
1055            self.assertFalse(key in auxv_dict)
1056            auxv_dict[key] = value
1057
1058        self.fail(
1059            "should not reach here - implies required double zero entry not found")
1060        return auxv_dict
1061
1062    def read_binary_data_in_chunks(self, command_prefix, chunk_length):
1063        """Collect command_prefix{offset:x},{chunk_length:x} until a single 'l' or 'l' with data is returned."""
1064        offset = 0
1065        done = False
1066        decoded_data = ""
1067
1068        while not done:
1069            # Grab the next iteration of data.
1070            self.reset_test_sequence()
1071            self.test_sequence.add_log_lines(
1072                [
1073                    "read packet: ${}{:x},{:x}:#00".format(
1074                        command_prefix,
1075                        offset,
1076                        chunk_length),
1077                    {
1078                        "direction": "send",
1079                        "regex": re.compile(
1080                            r"^\$([^E])(.*)#[0-9a-fA-F]{2}$",
1081                            re.MULTILINE | re.DOTALL),
1082                        "capture": {
1083                            1: "response_type",
1084                            2: "content_raw"}}],
1085                True)
1086
1087            context = self.expect_gdbremote_sequence()
1088            self.assertIsNotNone(context)
1089
1090            response_type = context.get("response_type")
1091            self.assertIsNotNone(response_type)
1092            self.assertTrue(response_type in ["l", "m"])
1093
1094            # Move offset along.
1095            offset += chunk_length
1096
1097            # Figure out if we're done.  We're done if the response type is l.
1098            done = response_type == "l"
1099
1100            # Decode binary data.
1101            content_raw = context.get("content_raw")
1102            if content_raw and len(content_raw) > 0:
1103                self.assertIsNotNone(content_raw)
1104                decoded_data += self.decode_gdbremote_binary(content_raw)
1105        return decoded_data
1106
1107    def add_interrupt_packets(self):
1108        self.test_sequence.add_log_lines([
1109            # Send the intterupt.
1110            "read packet: {}".format(chr(3)),
1111            # And wait for the stop notification.
1112            {"direction": "send",
1113             "regex": r"^\$T([0-9a-fA-F]{2})(.*)#[0-9a-fA-F]{2}$",
1114             "capture": {1: "stop_signo",
1115                         2: "stop_key_val_text"}},
1116        ], True)
1117
1118    def parse_interrupt_packets(self, context):
1119        self.assertIsNotNone(context.get("stop_signo"))
1120        self.assertIsNotNone(context.get("stop_key_val_text"))
1121        return (int(context["stop_signo"], 16), self.parse_key_val_dict(
1122            context["stop_key_val_text"]))
1123
1124    def add_QSaveRegisterState_packets(self, thread_id):
1125        if thread_id:
1126            # Use the thread suffix form.
1127            request = "read packet: $QSaveRegisterState;thread:{:x}#00".format(
1128                thread_id)
1129        else:
1130            request = "read packet: $QSaveRegisterState#00"
1131
1132        self.test_sequence.add_log_lines([request,
1133                                          {"direction": "send",
1134                                           "regex": r"^\$(E?.*)#[0-9a-fA-F]{2}$",
1135                                           "capture": {1: "save_response"}},
1136                                          ],
1137                                         True)
1138
1139    def parse_QSaveRegisterState_response(self, context):
1140        self.assertIsNotNone(context)
1141
1142        save_response = context.get("save_response")
1143        self.assertIsNotNone(save_response)
1144
1145        if len(save_response) < 1 or save_response[0] == "E":
1146            # error received
1147            return (False, None)
1148        else:
1149            return (True, int(save_response))
1150
1151    def add_QRestoreRegisterState_packets(self, save_id, thread_id=None):
1152        if thread_id:
1153            # Use the thread suffix form.
1154            request = "read packet: $QRestoreRegisterState:{};thread:{:x}#00".format(
1155                save_id, thread_id)
1156        else:
1157            request = "read packet: $QRestoreRegisterState:{}#00".format(
1158                save_id)
1159
1160        self.test_sequence.add_log_lines([
1161            request,
1162            "send packet: $OK#00"
1163        ], True)
1164
1165    def flip_all_bits_in_each_register_value(
1166            self, reg_infos, endian, thread_id=None):
1167        self.assertIsNotNone(reg_infos)
1168
1169        successful_writes = 0
1170        failed_writes = 0
1171
1172        for reg_info in reg_infos:
1173            # Use the lldb register index added to the reg info.  We're not necessarily
1174            # working off a full set of register infos, so an inferred register
1175            # index could be wrong.
1176            reg_index = reg_info["lldb_register_index"]
1177            self.assertIsNotNone(reg_index)
1178
1179            reg_byte_size = int(reg_info["bitsize"]) // 8
1180            self.assertTrue(reg_byte_size > 0)
1181
1182            # Handle thread suffix.
1183            if thread_id:
1184                p_request = "read packet: $p{:x};thread:{:x}#00".format(
1185                    reg_index, thread_id)
1186            else:
1187                p_request = "read packet: $p{:x}#00".format(reg_index)
1188
1189            # Read the existing value.
1190            self.reset_test_sequence()
1191            self.test_sequence.add_log_lines([
1192                p_request,
1193                {"direction": "send", "regex": r"^\$([0-9a-fA-F]+)#", "capture": {1: "p_response"}},
1194            ], True)
1195            context = self.expect_gdbremote_sequence()
1196            self.assertIsNotNone(context)
1197
1198            # Verify the response length.
1199            p_response = context.get("p_response")
1200            self.assertIsNotNone(p_response)
1201            initial_reg_value = unpack_register_hex_unsigned(
1202                endian, p_response)
1203
1204            # Flip the value by xoring with all 1s
1205            all_one_bits_raw = "ff" * (int(reg_info["bitsize"]) // 8)
1206            flipped_bits_int = initial_reg_value ^ int(all_one_bits_raw, 16)
1207            # print("reg (index={}, name={}): val={}, flipped bits (int={}, hex={:x})".format(reg_index, reg_info["name"], initial_reg_value, flipped_bits_int, flipped_bits_int))
1208
1209            # Handle thread suffix for P.
1210            if thread_id:
1211                P_request = "read packet: $P{:x}={};thread:{:x}#00".format(
1212                    reg_index, pack_register_hex(
1213                        endian, flipped_bits_int, byte_size=reg_byte_size), thread_id)
1214            else:
1215                P_request = "read packet: $P{:x}={}#00".format(
1216                    reg_index, pack_register_hex(
1217                        endian, flipped_bits_int, byte_size=reg_byte_size))
1218
1219            # Write the flipped value to the register.
1220            self.reset_test_sequence()
1221            self.test_sequence.add_log_lines([P_request,
1222                                              {"direction": "send",
1223                                               "regex": r"^\$(OK|E[0-9a-fA-F]+)#[0-9a-fA-F]{2}",
1224                                               "capture": {1: "P_response"}},
1225                                              ],
1226                                             True)
1227            context = self.expect_gdbremote_sequence()
1228            self.assertIsNotNone(context)
1229
1230            # Determine if the write succeeded.  There are a handful of registers that can fail, or partially fail
1231            # (e.g. flags, segment selectors, etc.) due to register value restrictions.  Don't worry about them
1232            # all flipping perfectly.
1233            P_response = context.get("P_response")
1234            self.assertIsNotNone(P_response)
1235            if P_response == "OK":
1236                successful_writes += 1
1237            else:
1238                failed_writes += 1
1239                # print("reg (index={}, name={}) write FAILED (error: {})".format(reg_index, reg_info["name"], P_response))
1240
1241            # Read back the register value, ensure it matches the flipped
1242            # value.
1243            if P_response == "OK":
1244                self.reset_test_sequence()
1245                self.test_sequence.add_log_lines([
1246                    p_request,
1247                    {"direction": "send", "regex": r"^\$([0-9a-fA-F]+)#", "capture": {1: "p_response"}},
1248                ], True)
1249                context = self.expect_gdbremote_sequence()
1250                self.assertIsNotNone(context)
1251
1252                verify_p_response_raw = context.get("p_response")
1253                self.assertIsNotNone(verify_p_response_raw)
1254                verify_bits = unpack_register_hex_unsigned(
1255                    endian, verify_p_response_raw)
1256
1257                if verify_bits != flipped_bits_int:
1258                    # Some registers, like mxcsrmask and others, will permute what's written.  Adjust succeed/fail counts.
1259                    # print("reg (index={}, name={}): read verify FAILED: wrote {:x}, verify read back {:x}".format(reg_index, reg_info["name"], flipped_bits_int, verify_bits))
1260                    successful_writes -= 1
1261                    failed_writes += 1
1262
1263        return (successful_writes, failed_writes)
1264
1265    def is_bit_flippable_register(self, reg_info):
1266        if not reg_info:
1267            return False
1268        if not "set" in reg_info:
1269            return False
1270        if reg_info["set"] != "General Purpose Registers":
1271            return False
1272        if ("container-regs" in reg_info) and (
1273                len(reg_info["container-regs"]) > 0):
1274            # Don't try to bit flip registers contained in another register.
1275            return False
1276        if re.match("^.s$", reg_info["name"]):
1277            # This is a 2-letter register name that ends in "s", like a segment register.
1278            # Don't try to bit flip these.
1279            return False
1280        if re.match("^(c|)psr$", reg_info["name"]):
1281            # This is an ARM program status register; don't flip it.
1282            return False
1283        # Okay, this looks fine-enough.
1284        return True
1285
1286    def read_register_values(self, reg_infos, endian, thread_id=None):
1287        self.assertIsNotNone(reg_infos)
1288        values = {}
1289
1290        for reg_info in reg_infos:
1291            # We append a register index when load reg infos so we can work
1292            # with subsets.
1293            reg_index = reg_info.get("lldb_register_index")
1294            self.assertIsNotNone(reg_index)
1295
1296            # Handle thread suffix.
1297            if thread_id:
1298                p_request = "read packet: $p{:x};thread:{:x}#00".format(
1299                    reg_index, thread_id)
1300            else:
1301                p_request = "read packet: $p{:x}#00".format(reg_index)
1302
1303            # Read it with p.
1304            self.reset_test_sequence()
1305            self.test_sequence.add_log_lines([
1306                p_request,
1307                {"direction": "send", "regex": r"^\$([0-9a-fA-F]+)#", "capture": {1: "p_response"}},
1308            ], True)
1309            context = self.expect_gdbremote_sequence()
1310            self.assertIsNotNone(context)
1311
1312            # Convert value from target endian to integral.
1313            p_response = context.get("p_response")
1314            self.assertIsNotNone(p_response)
1315            self.assertTrue(len(p_response) > 0)
1316            self.assertFalse(p_response[0] == "E")
1317
1318            values[reg_index] = unpack_register_hex_unsigned(
1319                endian, p_response)
1320
1321        return values
1322
1323    def add_vCont_query_packets(self):
1324        self.test_sequence.add_log_lines(["read packet: $vCont?#49",
1325                                          {"direction": "send",
1326                                           "regex": r"^\$(vCont)?(.*)#[0-9a-fA-F]{2}$",
1327                                           "capture": {2: "vCont_query_response"}},
1328                                          ],
1329                                         True)
1330
1331    def parse_vCont_query_response(self, context):
1332        self.assertIsNotNone(context)
1333        vCont_query_response = context.get("vCont_query_response")
1334
1335        # Handle case of no vCont support at all - in which case the capture
1336        # group will be none or zero length.
1337        if not vCont_query_response or len(vCont_query_response) == 0:
1338            return {}
1339
1340        return {key: 1 for key in vCont_query_response.split(
1341            ";") if key and len(key) > 0}
1342
1343    def count_single_steps_until_true(
1344            self,
1345            thread_id,
1346            predicate,
1347            args,
1348            max_step_count=100,
1349            use_Hc_packet=True,
1350            step_instruction="s"):
1351        """Used by single step test that appears in a few different contexts."""
1352        single_step_count = 0
1353
1354        while single_step_count < max_step_count:
1355            self.assertIsNotNone(thread_id)
1356
1357            # Build the packet for the single step instruction.  We replace
1358            # {thread}, if present, with the thread_id.
1359            step_packet = "read packet: ${}#00".format(
1360                re.sub(r"{thread}", "{:x}".format(thread_id), step_instruction))
1361            # print("\nstep_packet created: {}\n".format(step_packet))
1362
1363            # Single step.
1364            self.reset_test_sequence()
1365            if use_Hc_packet:
1366                self.test_sequence.add_log_lines(
1367                    [  # Set the continue thread.
1368                        "read packet: $Hc{0:x}#00".format(thread_id),
1369                        "send packet: $OK#00",
1370                    ], True)
1371            self.test_sequence.add_log_lines([
1372                # Single step.
1373                step_packet,
1374                # "read packet: $vCont;s:{0:x}#00".format(thread_id),
1375                # Expect a breakpoint stop report.
1376                {"direction": "send",
1377                 "regex": r"^\$T([0-9a-fA-F]{2})thread:([0-9a-fA-F]+);",
1378                 "capture": {1: "stop_signo",
1379                             2: "stop_thread_id"}},
1380            ], True)
1381            context = self.expect_gdbremote_sequence()
1382            self.assertIsNotNone(context)
1383            self.assertIsNotNone(context.get("stop_signo"))
1384            self.assertEqual(int(context.get("stop_signo"), 16),
1385                             lldbutil.get_signal_number('SIGTRAP'))
1386
1387            single_step_count += 1
1388
1389            # See if the predicate is true.  If so, we're done.
1390            if predicate(args):
1391                return (True, single_step_count)
1392
1393        # The predicate didn't return true within the runaway step count.
1394        return (False, single_step_count)
1395
1396    def g_c1_c2_contents_are(self, args):
1397        """Used by single step test that appears in a few different contexts."""
1398        g_c1_address = args["g_c1_address"]
1399        g_c2_address = args["g_c2_address"]
1400        expected_g_c1 = args["expected_g_c1"]
1401        expected_g_c2 = args["expected_g_c2"]
1402
1403        # Read g_c1 and g_c2 contents.
1404        self.reset_test_sequence()
1405        self.test_sequence.add_log_lines(
1406            ["read packet: $m{0:x},{1:x}#00".format(g_c1_address, 1),
1407             {"direction": "send", "regex": r"^\$(.+)#[0-9a-fA-F]{2}$", "capture": {1: "g_c1_contents"}},
1408             "read packet: $m{0:x},{1:x}#00".format(g_c2_address, 1),
1409             {"direction": "send", "regex": r"^\$(.+)#[0-9a-fA-F]{2}$", "capture": {1: "g_c2_contents"}}],
1410            True)
1411
1412        # Run the packet stream.
1413        context = self.expect_gdbremote_sequence()
1414        self.assertIsNotNone(context)
1415
1416        # Check if what we read from inferior memory is what we are expecting.
1417        self.assertIsNotNone(context.get("g_c1_contents"))
1418        self.assertIsNotNone(context.get("g_c2_contents"))
1419
1420        return (seven.unhexlify(context.get("g_c1_contents")) == expected_g_c1) and (
1421            seven.unhexlify(context.get("g_c2_contents")) == expected_g_c2)
1422
1423    def single_step_only_steps_one_instruction(
1424            self, use_Hc_packet=True, step_instruction="s"):
1425        """Used by single step test that appears in a few different contexts."""
1426        # Start up the inferior.
1427        procs = self.prep_debug_monitor_and_inferior(
1428            inferior_args=[
1429                "get-code-address-hex:swap_chars",
1430                "get-data-address-hex:g_c1",
1431                "get-data-address-hex:g_c2",
1432                "sleep:1",
1433                "call-function:swap_chars",
1434                "sleep:5"])
1435
1436        # Run the process
1437        self.test_sequence.add_log_lines(
1438            [  # Start running after initial stop.
1439                "read packet: $c#63",
1440                # Match output line that prints the memory address of the function call entry point.
1441                # Note we require launch-only testing so we can get inferior otuput.
1442                {"type": "output_match", "regex": r"^code address: 0x([0-9a-fA-F]+)\r\ndata address: 0x([0-9a-fA-F]+)\r\ndata address: 0x([0-9a-fA-F]+)\r\n$",
1443                 "capture": {1: "function_address", 2: "g_c1_address", 3: "g_c2_address"}},
1444                # Now stop the inferior.
1445                "read packet: {}".format(chr(3)),
1446                # And wait for the stop notification.
1447                {"direction": "send", "regex": r"^\$T([0-9a-fA-F]{2})thread:([0-9a-fA-F]+);", "capture": {1: "stop_signo", 2: "stop_thread_id"}}],
1448            True)
1449
1450        # Run the packet stream.
1451        context = self.expect_gdbremote_sequence()
1452        self.assertIsNotNone(context)
1453
1454        # Grab the main thread id.
1455        self.assertIsNotNone(context.get("stop_thread_id"))
1456        main_thread_id = int(context.get("stop_thread_id"), 16)
1457
1458        # Grab the function address.
1459        self.assertIsNotNone(context.get("function_address"))
1460        function_address = int(context.get("function_address"), 16)
1461
1462        # Grab the data addresses.
1463        self.assertIsNotNone(context.get("g_c1_address"))
1464        g_c1_address = int(context.get("g_c1_address"), 16)
1465
1466        self.assertIsNotNone(context.get("g_c2_address"))
1467        g_c2_address = int(context.get("g_c2_address"), 16)
1468
1469        # Set a breakpoint at the given address.
1470        if self.getArchitecture().startswith("arm"):
1471            # TODO: Handle case when setting breakpoint in thumb code
1472            BREAKPOINT_KIND = 4
1473        else:
1474            BREAKPOINT_KIND = 1
1475        self.reset_test_sequence()
1476        self.add_set_breakpoint_packets(
1477            function_address,
1478            do_continue=True,
1479            breakpoint_kind=BREAKPOINT_KIND)
1480        context = self.expect_gdbremote_sequence()
1481        self.assertIsNotNone(context)
1482
1483        # Remove the breakpoint.
1484        self.reset_test_sequence()
1485        self.add_remove_breakpoint_packets(
1486            function_address, breakpoint_kind=BREAKPOINT_KIND)
1487        context = self.expect_gdbremote_sequence()
1488        self.assertIsNotNone(context)
1489
1490        # Verify g_c1 and g_c2 match expected initial state.
1491        args = {}
1492        args["g_c1_address"] = g_c1_address
1493        args["g_c2_address"] = g_c2_address
1494        args["expected_g_c1"] = "0"
1495        args["expected_g_c2"] = "1"
1496
1497        self.assertTrue(self.g_c1_c2_contents_are(args))
1498
1499        # Verify we take only a small number of steps to hit the first state.
1500        # Might need to work through function entry prologue code.
1501        args["expected_g_c1"] = "1"
1502        args["expected_g_c2"] = "1"
1503        (state_reached,
1504         step_count) = self.count_single_steps_until_true(main_thread_id,
1505                                                          self.g_c1_c2_contents_are,
1506                                                          args,
1507                                                          max_step_count=25,
1508                                                          use_Hc_packet=use_Hc_packet,
1509                                                          step_instruction=step_instruction)
1510        self.assertTrue(state_reached)
1511
1512        # Verify we hit the next state.
1513        args["expected_g_c1"] = "1"
1514        args["expected_g_c2"] = "0"
1515        (state_reached,
1516         step_count) = self.count_single_steps_until_true(main_thread_id,
1517                                                          self.g_c1_c2_contents_are,
1518                                                          args,
1519                                                          max_step_count=5,
1520                                                          use_Hc_packet=use_Hc_packet,
1521                                                          step_instruction=step_instruction)
1522        self.assertTrue(state_reached)
1523        expected_step_count = 1
1524        arch = self.getArchitecture()
1525
1526        # MIPS required "3" (ADDIU, SB, LD) machine instructions for updation
1527        # of variable value
1528        if re.match("mips", arch):
1529            expected_step_count = 3
1530        # S390X requires "2" (LARL, MVI) machine instructions for updation of
1531        # variable value
1532        if re.match("s390x", arch):
1533            expected_step_count = 2
1534        # ARM64 requires "4" instructions: 2 to compute the address (adrp, add),
1535        # one to materialize the constant (mov) and the store
1536        if re.match("arm64", arch):
1537            expected_step_count = 4
1538
1539        self.assertEqual(step_count, expected_step_count)
1540
1541        # ARM64: Once addresses and constants are materialized, only one
1542        # instruction is needed.
1543        if re.match("arm64", arch):
1544            expected_step_count = 1
1545
1546        # Verify we hit the next state.
1547        args["expected_g_c1"] = "0"
1548        args["expected_g_c2"] = "0"
1549        (state_reached,
1550         step_count) = self.count_single_steps_until_true(main_thread_id,
1551                                                          self.g_c1_c2_contents_are,
1552                                                          args,
1553                                                          max_step_count=5,
1554                                                          use_Hc_packet=use_Hc_packet,
1555                                                          step_instruction=step_instruction)
1556        self.assertTrue(state_reached)
1557        self.assertEqual(step_count, expected_step_count)
1558
1559        # Verify we hit the next state.
1560        args["expected_g_c1"] = "0"
1561        args["expected_g_c2"] = "1"
1562        (state_reached,
1563         step_count) = self.count_single_steps_until_true(main_thread_id,
1564                                                          self.g_c1_c2_contents_are,
1565                                                          args,
1566                                                          max_step_count=5,
1567                                                          use_Hc_packet=use_Hc_packet,
1568                                                          step_instruction=step_instruction)
1569        self.assertTrue(state_reached)
1570        self.assertEqual(step_count, expected_step_count)
1571
1572    def maybe_strict_output_regex(self, regex):
1573        return '.*' + regex + \
1574            '.*' if lldbplatformutil.hasChattyStderr(self) else '^' + regex + '$'
1575
1576    def install_and_create_launch_args(self):
1577        exe_path = self.getBuildArtifact("a.out")
1578        if not lldb.remote_platform:
1579            return [exe_path]
1580        remote_path = lldbutil.append_to_process_working_directory(self,
1581            os.path.basename(exe_path))
1582        remote_file_spec = lldb.SBFileSpec(remote_path, False)
1583        err = lldb.remote_platform.Install(lldb.SBFileSpec(exe_path, True),
1584                                           remote_file_spec)
1585        if err.Fail():
1586            raise Exception("remote_platform.Install('%s', '%s') failed: %s" %
1587                            (exe_path, remote_path, err))
1588        return [remote_path]
1589