[Lldb-commits] [lldb] [lldb] Detect a Darwin kernel issue and work around it (PR #81573)

[Adrian Prantl via lldb-commits]

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@@ -825,6 +806,56 @@ StopInfoSP StopInfoMachException::CreateStopReasonWithMachException(
     break;
   }
 
-  return StopInfoSP(new StopInfoMachException(thread, exc_type, exc_data_count,
-                                              exc_code, exc_sub_code));
+  return std::make_shared<StopInfoMachException>(
+      thread, exc_type, exc_data_count, exc_code, exc_sub_code,
+      not_stepping_but_got_singlestep_exception);
+}
+
+// Detect an unusual situation on Darwin where:
+//
+//   0. We did an instruction-step before this.
+//   1. We have a hardware breakpoint or watchpoint set.
+//   2. We resumed the process, but not with an instruction-step.
+//   3. The thread gets an "instruction-step completed" mach exception.
+//   4. The pc has not advanced - it is the same as before.
+//
+// This method returns true for that combination of events.
+bool StopInfoMachException::WasContinueInterrupted(Thread &thread) {
+  Log *log = GetLog(LLDBLog::Step);
+
+  // We got an instruction-step completed mach exception but we were not
+  // doing an instruction step on this thread.
+  if (!m_not_stepping_but_got_singlestep_exception)
+    return false;
+
+  RegisterContextSP reg_ctx_sp(thread.GetRegisterContext());
+  std::optional<addr_t> prev_pc = thread.GetPreviousFrameZeroPC();
+  if (!reg_ctx_sp || !prev_pc)
+    return false;
+
+  // The previous pc value and current pc value are the same.
+  if (*prev_pc != reg_ctx_sp->GetPC())
+    return false;
+
+  // We have a watchpoint -- this is the kernel bug.
+  ProcessSP process_sp = thread.GetProcess();
+  if (process_sp->GetWatchpointResourceList().GetSize()) {
+    LLDB_LOGF(log,
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adrian-prantl wrote:

This can be the more modern LLDB_LOG

https://github.com/llvm/llvm-project/pull/81573