validate: launcher: Add support for lldb

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/7452>

subprojects/gst-devtools/validate/launcher/baseclasses.py

@@ -79,6 +79,63 @@ EXITING_SIGNALS.update({(v, k) for k, v in EXITING_SIGNALS.items()})
 
 
 CI_ARTIFACTS_URL = os.environ.get('CI_ARTIFACTS_URL')
+DEBUGGER = None
+
+
+def get_debugger():
+    global DEBUGGER
+    if DEBUGGER is not None:
+        return DEBUGGER
+
+    gdb = shutil.which('gdb')
+    if gdb:
+        DEBUGGER = GDBDebugger(gdb)
+    else:
+        lldb = shutil.which('lldb')
+        DEBUGGER = LLDBDebugger(lldb)
+
+    return DEBUGGER
+
+
+class Debugger:
+    def __init__(self, executable):
+        self.executable = executable
+
+    def get_args(self, args, non_stop) -> list:
+        raise NotImplementedError
+
+    def get_attach_args(self, pid):
+        raise NotImplementedError
+
+
+class GDBDebugger(Debugger):
+    def get_args(self, args, non_stop) -> list:
+        if non_stop:
+            return [
+                self.executable,
+                "-ex",
+                "run",
+                "-ex",
+                "bt",
+                "-ex",
+                "quit",
+                "--args",
+            ] + args
+        else:
+            return [self.executable, "--args"] + args
+
+    def get_attach_args(self, pid):
+        return [self.executable, "-p", str(pid)]
+
+
+class LLDBDebugger(Debugger):
+    def get_args(self, args, non_stop) -> list:
+        if non_stop:
+            return [self.executable, "-o", "run", "-o", "bt", "-o", "quit", "--"] + args
+        return [self.executable, "--"] + args
+
+    def get_attach_args(self, pid):
+        return [self.executable, "-p", str(pid)]
 
 
 class Test(Loggable):
@@ -365,6 +422,7 @@ class Test(Loggable):
                                                                     message, error))
 
         if result is Result.TIMEOUT:
+            self.add_stack_trace_to_logfile()
             if self.options.debug is True:
                 if self.options.gdb:
                     printc("Timeout, you should process <ctrl>c to get into gdb",
@@ -373,11 +431,21 @@ class Test(Loggable):
                     self.process.communicate()
                 else:
                     pname = self.command[0]
-                    input("%sTimeout happened  on %s you can attach gdb doing:\n $gdb %s %d%s\n"
-                          "Press enter to continue" % (Colors.FAIL, self.classname,
-                          pname, self.process.pid, Colors.ENDC))
+                    while True:
+                        debugger = get_debugger()
+                        if not debugger:
+                            res = input(f"{Colors.FAIL}Timeout happened on {self.classname} no known debugger found but the process PID is {self.process.pid}\n"
+                                f"You can find log file at {self.logfile}\n"
+                                f"Press 'ok(o)' enter to continue\n\n")
                         else:
-                self.add_stack_trace_to_logfile()
+                            res = input(f"{Colors.FAIL}Timeout happened on {self.classname} you can attach the debugger doing:\n"
+                                    f"   $ {' '.join([shlex.quote(a) for a in debugger.get_attach_args(self.process.pid)])}\n"
+                                    f"You can find log file at {self.logfile}\n"
+                                    f"**Press ok(o) to continue**{Colors.ENDC}\n\n")
+
+                        if res.lower() in ['o', 'ok']:
+                            print("Continuing...\n")
+                            break
 
         self.result = result
         self.message = message
@@ -544,10 +612,8 @@ class Test(Loggable):
             self.timeout = sys.maxsize
             self.hard_timeout = sys.maxsize
 
-        args = ["gdb"]
-        if self.options.gdb_non_stop:
-            args += ["-ex", "run", "-ex", "backtrace", "-ex", "quit"]
-        args += ["--args"] + command
+        assert DEBUGGER is not None
+        args = DEBUGGER.get_args(command, self.options.gdb_non_stop)
         return args
 
     def use_rr(self, command, subenv):
@@ -1621,6 +1687,10 @@ class TestsManager(Loggable):
             for patterns in options.blacklisted_tests:
                 self._add_blacklist(patterns)
 
+        if options.gdb:
+            if get_debugger() is None:
+                raise RuntimeError("No debugger found, can't run tests with --gdb")
+
     def check_blacklists(self):
         if self.options.check_bugs_status:
             if not check_bugs_resolution(self.blacklisted_tests):

subprojects/gst-devtools/validate/launcher/main.py

@@ -266,12 +266,6 @@ class LauncherConfig(Loggable):
             self.logsdir = "stdout"
             self.debug = True
             self.num_jobs = 1
-            try:
-                subprocess.check_output("gdb --help", shell=True)
-            except subprocess.CalledProcessError:
-                printc("Want to use gdb, but not available on the system",
-                       Colors.FAIL)
-                return False
 
         # other output directories
         if self.logsdir in ['stdout', 'stderr']:

subprojects/gst-devtools/validate/launcher/utils.py

@@ -385,6 +385,7 @@ class BackTraceGenerator(Loggable):
             self.warning(e)
             self.coredumpctl = None
         self.gdb = shutil.which('gdb')
+        self.lldb = shutil.which('lldb')
 
     @classmethod
     def get_default(cls):
@@ -404,8 +405,21 @@ class BackTraceGenerator(Loggable):
                    " supported way to get backtraces for now.")
         return None
 
+    def get_trace_on_running_process_with_lldb(self, test):
+        lldb = ['lldb', '-o', 'bt all', '-o', 'quit', '-p', str(test.process.pid)]
+
+        try:
+            return subprocess.check_output(
+                lldb, stderr=subprocess.STDOUT, timeout=30).decode()
+        except Exception as e:
+            return "Could not run `lldb` on process (pid: %d):\n%s" % (
+                test.process.pid, e)
+
     def get_trace_on_running_process(self, test):
         if not self.gdb:
+            if self.lldb:
+                return self.get_trace_on_running_process_with_lldb(test)
+
             return "Can not generate stack trace as `gdb` is not" \
                 "installed."