[lldb] Add "Trace" stop reason in Scripted Thread

[mib]

Summary

This patch adds support to eStopReasonTrace to Scripted Threads.

This is necessary when using a Scrited Process with a Scripted Thread
Plan to report a special thread stop reason to the thread plan.

rdar://109425542

Signed-off-by: Med Ismail Bennani <[e-mail]>

[mib]

lldb/test/API/functionalities/scripted_process/dummy_scripted_process.py

70–71

Other tests still user a lldb.eStopReasonSignal with Scripted Processes so we can just replace this by an lldb.eStopReasonTrace instead

[JDevlieghere]

LGTM. Are there other stop reasons that are currently not supported by scripted threads that we should consider supporting?

[mib]

In D151043#4360968, @JDevlieghere wrote:

LGTM. Are there other stop reasons that are currently not supported by scripted threads that we should consider supporting?

Scripted Threads still don't support eStopReasonWatchpoint as well as all of these stop reasons :

eStopReasonExec,
eStopReasonPlanComplete,
eStopReasonThreadExiting,
eStopReasonInstrumentation,
eStopReasonProcessorTrace,
eStopReasonFork,
eStopReasonVFork,
eStopReasonVForkDone,

I'll implement the watchpoint stop info in a follow-up (should very similar to the breakpoint stop info), but I'm not sure if need to implement support to any of the other ... @jingham, what do you think ?

[jingham]

If a Scripted process is able to provide private events and enough info to lldb's lower level calls (read memory, registers) to work the thread-plan machinery then it won't need to generate the inferred stop reasons like PlanComplete and Instrumentation. But the scripted threads might just be producing public stops w/o the underlying model that would allow lldb to generate them. In that case, the scripted thread will also need to be able to produce the inferred stop reasons.

lldb/source/Plugins/Process/scripted/ScriptedThread.cpp

case lldb::eStopReasonSignal: {
     int signal;
     llvm::StringRef description;
     data_dict->GetValueForKeyAsInteger("signal", signal,
                                        LLDB_INVALID_SIGNAL_NUMBER);
     data_dict->GetValueForKeyAsString("desc", description);
     stop_info_sp =
         StopInfo::CreateStopReasonWithSignal(*this, signal, description.data());
   } break;
+  case lldb::eStopReasonTrace: {
+    stop_info_sp = StopInfo::CreateStopReasonToTrace(*this);
+  } break;
   case lldb::eStopReasonException: {
 #if defined(__APPLE__)
     StructuredData::Dictionary *mach_exception;
     if (data_dict->GetValueForKeyAsDictionary("mach_exception",
                                               mach_exception)) {
       llvm::StringRef value;
       mach_exception->GetValueForKeyAsString("type", value);
       auto exc_type =

lldb/test/API/functionalities/scripted_process/TestScriptedProcess.py

def test_scripted_process_and_scripted_thread(self):
         buff = process_0.ReadCStringFromMemory(addr, len(message) + 1, error)
         self.assertSuccess(error)
         self.assertEqual(buff, message)
 
         thread = process_0.GetSelectedThread()
         self.assertTrue(thread, "Invalid thread.")
         self.assertEqual(thread.GetThreadID(), 0x19)
         self.assertEqual(thread.GetName(), "DummyScriptedThread.thread-1")
-        self.assertStopReason(thread.GetStopReason(), lldb.eStopReasonSignal)
+        self.assertStopReason(thread.GetStopReason(), lldb.eStopReasonTrace)
 
         self.assertGreater(thread.GetNumFrames(), 0)
 
         frame = thread.GetFrameAtIndex(0)
         GPRs = None
         register_set = frame.registers # Returns an SBValueList.
         for regs in register_set:
             if 'general purpose' in regs.name.lower():

lldb/test/API/functionalities/scripted_process/dummy_scripted_process.py

class DummyScriptedThread(ScriptedThread):
 
     def get_name(self) -> str:
         return DummyScriptedThread.__name__ + ".thread-1"
 
     def get_state(self) -> int:
         return lldb.eStateStopped
 
     def get_stop_reason(self) -> Dict[str, Any]:
-        return { "type": lldb.eStopReasonSignal, "data": {
-            "signal": signal.SIGINT
-        } }
+        return { "type": lldb.eStopReasonTrace, "data": {} }
 
     def get_register_context(self) -> str:
         return struct.pack(
                 '21Q', 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
 
 
 def __lldb_init_module(debugger, dict):
     if not 'SKIP_SCRIPTED_PROCESS_LAUNCH' in os.environ:
         debugger.HandleCommand(
             "process launch -C %s.%s" % (__name__,
                                      DummyScriptedProcess.__name__))
     else:
         print("Name of the class that will manage the scripted process: '%s.%s'"
                 % (__name__, DummyScriptedProcess.__name__))