On x86 & x86_64, try to use eh_frame for frame 0.

We decided to use assmbly profiler instead of eh_frame for frame 0 because for compiler generated code, eh_frame is usually synchronous(a.k.a. only valid at call site); and we have no way to tell if it's asynchronous or not.
But for x86 & x86_64 compiler generated code:
1. clang & GCC describes all prologue instructions in eh_frame;
2. mid-function stack pointer altering instructions can be easily detected.
So we can grab eh_frame, and use assembly profiler to augment it into asynchronous unwind table.
This change also benefits hand-written assembly; eh_frame for hand-written assembly is often asynchronous,so we have a much better chance to successfully unwind through them.

Change by Tong Shen.

llvm-svn: 216406

1 files changed, 2 insertions, 2 deletions

diff --git a/lldb/source/Plugins/Process/Utility/RegisterContextLLDB.cpp b/lldb/source/Plugins/Process/Utility/RegisterContextLLDB.cpp
index cfbe133f146..b58e6bb607e 100644
--- a/lldb/source/Plugins/Process/Utility/RegisterContextLLDB.cpp
+++ b/lldb/source/Plugins/Process/Utility/RegisterContextLLDB.cpp
@@ -794,7 +794,7 @@ RegisterContextLLDB::GetFullUnwindPlanForFrame ()
     // Typically the NonCallSite UnwindPlan is the unwind created by inspecting the assembly language instructions
     if (behaves_like_zeroth_frame)
     {
-        unwind_plan_sp = func_unwinders_sp->GetUnwindPlanAtNonCallSite (m_thread);
+        unwind_plan_sp = func_unwinders_sp->GetUnwindPlanAtNonCallSite (process->GetTarget(), m_thread, m_current_offset_backed_up_one);
         if (unwind_plan_sp && unwind_plan_sp->PlanValidAtAddress (m_current_pc))
         {
             if (unwind_plan_sp->GetSourcedFromCompiler() == eLazyBoolNo)
@@ -822,7 +822,7 @@ RegisterContextLLDB::GetFullUnwindPlanForFrame ()
 
     // We'd prefer to use an UnwindPlan intended for call sites when we're at a call site but if we've
     // struck out on that, fall back to using the non-call-site assembly inspection UnwindPlan if possible.
-    unwind_plan_sp = func_unwinders_sp->GetUnwindPlanAtNonCallSite (m_thread);
+    unwind_plan_sp = func_unwinders_sp->GetUnwindPlanAtNonCallSite (process->GetTarget(), m_thread, m_current_offset_backed_up_one);
     if (unwind_plan_sp && unwind_plan_sp->GetSourcedFromCompiler() == eLazyBoolNo)
     {
         // We probably have an UnwindPlan created by inspecting assembly instructions, and we probably