[Lldb-commits] [PATCH] D16825: [Windows] Set correct thread stop info when single-step lands on a breakpoint

[Adrian McCarthy via lldb-commits]

amccarth created this revision.
amccarth added a reviewer: zturner.
amccarth added a subscriber: lldb-commits.

I don't understand how this works before, but this fixes the recent test regressions on Windows in TestConsecutiveBreakpoints.py.

LLDB wasn't stopping when single-stepping onto a breakpoint.  (Note that `process continue` from one breakpoint starts with a single-step, so you don't have to be explicitly single-stepping to run into this problem.)

The solution is to check if the single step lands on a breakpoint, and, if it does, to treat that like a breakpoint hint.  Note there's a subtle difference in the PC (program counter) compared to actually hitting a breakpoint.

This fixes TestConsecutiveBreakpoints.py on Windows, and no other tests regress.  Ran clang-format.

http://reviews.llvm.org/D16825

Files:
  source/Plugins/Process/Windows/Live/ProcessWindowsLive.cpp

Index: source/Plugins/Process/Windows/Live/ProcessWindowsLive.cpp
===================================================================
--- source/Plugins/Process/Windows/Live/ProcessWindowsLive.cpp
+++ source/Plugins/Process/Windows/Live/ProcessWindowsLive.cpp
@@ -554,11 +554,25 @@
     {
         case EXCEPTION_SINGLE_STEP:
         {
-            stop_info = StopInfo::CreateStopReasonToTrace(*stop_thread);
-            stop_thread->SetStopInfo(stop_info);
-            WINLOG_IFANY(WINDOWS_LOG_EXCEPTION | WINDOWS_LOG_STEP, "RefreshStateAfterStop single stepping thread %u",
-                         stop_thread->GetID());
-            stop_thread->SetStopInfo(stop_info);
+            RegisterContextSP register_context = stop_thread->GetRegisterContext();
+            const uint64_t pc = register_context->GetPC();
+            BreakpointSiteSP site(GetBreakpointSiteList().FindByAddress(pc));
+            if (site && site->ValidForThisThread(stop_thread.get()))
+            {
+                WINLOG_IFANY(WINDOWS_LOG_BREAKPOINTS | WINDOWS_LOG_EXCEPTION | WINDOWS_LOG_STEP,
+                             "Single-stepped onto a breakpoint in process %I64u at "
+                             "address 0x%I64x with breakpoint site %d",
+                             m_session_data->m_debugger->GetProcess().GetProcessId(), pc, site->GetID());
+                stop_info = StopInfo::CreateStopReasonWithBreakpointSiteID(*stop_thread, site->GetID());
+                stop_thread->SetStopInfo(stop_info);
+            }
+            else
+            {
+                WINLOG_IFANY(WINDOWS_LOG_EXCEPTION | WINDOWS_LOG_STEP,
+                             "RefreshStateAfterStop single stepping thread %u", stop_thread->GetID());
+                stop_info = StopInfo::CreateStopReasonToTrace(*stop_thread);
+                stop_thread->SetStopInfo(stop_info);
+            }
             return;
         }
 


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