1 files changed, 104 insertions, 18 deletions

diff --git a/lldb/source/Target/StackFrameList.cpp b/lldb/source/Target/StackFrameList.cpp
index c782b506a9cb..2841f512439a 100644
--- a/lldb/source/Target/StackFrameList.cpp
+++ b/lldb/source/Target/StackFrameList.cpp
@@ -9,6 +9,7 @@
 #include "lldb/Target/StackFrameList.h"
 #include "lldb/Breakpoint/Breakpoint.h"
 #include "lldb/Breakpoint/BreakpointLocation.h"
+#include "lldb/Core/Debugger.h"
 #include "lldb/Core/SourceManager.h"
 #include "lldb/Core/StreamFile.h"
 #include "lldb/Symbol/Block.h"
@@ -17,6 +18,7 @@
 #include "lldb/Target/Process.h"
 #include "lldb/Target/RegisterContext.h"
 #include "lldb/Target/StackFrame.h"
+#include "lldb/Target/StackFrameRecognizer.h"
 #include "lldb/Target/StopInfo.h"
 #include "lldb/Target/Target.h"
 #include "lldb/Target/Thread.h"
@@ -37,7 +39,7 @@ StackFrameList::StackFrameList(Thread &thread,
                                const lldb::StackFrameListSP &prev_frames_sp,
                                bool show_inline_frames)
     : m_thread(thread), m_prev_frames_sp(prev_frames_sp), m_mutex(), m_frames(),
-      m_selected_frame_idx(0), m_concrete_frames_fetched(0),
+      m_selected_frame_idx(), m_concrete_frames_fetched(0),
       m_current_inlined_depth(UINT32_MAX),
       m_current_inlined_pc(LLDB_INVALID_ADDRESS),
       m_show_inlined_frames(show_inline_frames) {
@@ -83,8 +85,8 @@ void StackFrameList::ResetCurrentInlinedDepth() {
     return;
 
   std::lock_guard<std::recursive_mutex> guard(m_mutex);
-
-  GetFramesUpTo(0);
+  
+  GetFramesUpTo(0, DoNotAllowInterruption);
   if (m_frames.empty())
     return;
   if (!m_frames[0]->IsInlined()) {
@@ -251,7 +253,7 @@ struct CallDescriptor {
 using CallSequence = std::vector<CallDescriptor>;
 
 /// Find the unique path through the call graph from \p begin (with return PC
-/// \p return_pc) to \p end. On success this path is stored into \p path, and 
+/// \p return_pc) to \p end. On success this path is stored into \p path, and
 /// on failure \p path is unchanged.
 static void FindInterveningFrames(Function &begin, Function &end,
                                   ExecutionContext &exe_ctx, Target &target,
@@ -434,21 +436,23 @@ void StackFrameList::SynthesizeTailCallFrames(StackFrame &next_frame) {
     next_frame.SetFrameIndex(m_frames.size());
 }
 
-void StackFrameList::GetFramesUpTo(uint32_t end_idx) {
+bool StackFrameList::GetFramesUpTo(uint32_t end_idx,
+                                   InterruptionControl allow_interrupt) {
   // Do not fetch frames for an invalid thread.
+  bool was_interrupted = false;
   if (!m_thread.IsValid())
-    return;
+    return false;
 
   // We've already gotten more frames than asked for, or we've already finished
   // unwinding, return.
   if (m_frames.size() > end_idx || GetAllFramesFetched())
-    return;
+    return false;
 
   Unwind &unwinder = m_thread.GetUnwinder();
 
   if (!m_show_inlined_frames) {
     GetOnlyConcreteFramesUpTo(end_idx, unwinder);
-    return;
+    return false;
   }
 
 #if defined(DEBUG_STACK_FRAMES)
@@ -470,6 +474,7 @@ void StackFrameList::GetFramesUpTo(uint32_t end_idx) {
   }
 
   StackFrameSP unwind_frame_sp;
+  Debugger &dbg = m_thread.GetProcess()->GetTarget().GetDebugger();
   do {
     uint32_t idx = m_concrete_frames_fetched++;
     lldb::addr_t pc = LLDB_INVALID_ADDRESS;
@@ -502,6 +507,15 @@ void StackFrameList::GetFramesUpTo(uint32_t end_idx) {
         cfa = unwind_frame_sp->m_id.GetCallFrameAddress();
       }
     } else {
+      // Check for interruption when building the frames.
+      // Do the check in idx > 0 so that we'll always create a 0th frame.
+      if (allow_interrupt 
+          && INTERRUPT_REQUESTED(dbg, "Interrupted having fetched {0} frames",
+                                 m_frames.size())) {
+          was_interrupted = true;
+          break;
+      }
+
       const bool success =
           unwinder.GetFrameInfoAtIndex(idx, cfa, pc, behaves_like_zeroth_frame);
       if (!success) {
@@ -614,14 +628,19 @@ void StackFrameList::GetFramesUpTo(uint32_t end_idx) {
   Dump(&s);
   s.EOL();
 #endif
+  // Don't report interrupted if we happen to have gotten all the frames:
+  if (!GetAllFramesFetched())
+    return was_interrupted;
+  return false;
 }
 
 uint32_t StackFrameList::GetNumFrames(bool can_create) {
   std::lock_guard<std::recursive_mutex> guard(m_mutex);
 
-  if (can_create)
-    GetFramesUpTo(UINT32_MAX);
-
+  if (can_create) {
+    // Don't allow interrupt or we might not return the correct count
+    GetFramesUpTo(UINT32_MAX, DoNotAllowInterruption); 
+  }
   return GetVisibleStackFrameIndex(m_frames.size());
 }
 
@@ -662,7 +681,13 @@ StackFrameSP StackFrameList::GetFrameAtIndex(uint32_t idx) {
 
   // GetFramesUpTo will fill m_frames with as many frames as you asked for, if
   // there are that many.  If there weren't then you asked for too many frames.
-  GetFramesUpTo(idx);
+  // GetFramesUpTo returns true if interrupted:
+  if (GetFramesUpTo(idx)) {
+    Log *log = GetLog(LLDBLog::Thread);
+    LLDB_LOG(log, "GetFrameAtIndex was interrupted");
+    return {};
+  }
+
   if (idx < m_frames.size()) {
     if (m_show_inlined_frames) {
       // When inline frames are enabled we actually create all the frames in
@@ -772,9 +797,52 @@ bool StackFrameList::SetFrameAtIndex(uint32_t idx, StackFrameSP &frame_sp) {
   return false; // resize failed, out of memory?
 }
 
-uint32_t StackFrameList::GetSelectedFrameIndex() const {
+void StackFrameList::SelectMostRelevantFrame() {
+  // Don't call into the frame recognizers on the private state thread as
+  // they can cause code to run in the target, and that can cause deadlocks
+  // when fetching stop events for the expression.
+  if (m_thread.GetProcess()->CurrentThreadIsPrivateStateThread())
+    return;
+
+  Log *log = GetLog(LLDBLog::Thread);
+
+  // Only the top frame should be recognized.
+  StackFrameSP frame_sp = GetFrameAtIndex(0);
+  if (!frame_sp) {
+    LLDB_LOG(log, "Failed to construct Frame #0");
+    return;
+  }
+
+  RecognizedStackFrameSP recognized_frame_sp = frame_sp->GetRecognizedFrame();
+
+  if (!recognized_frame_sp) {
+    LLDB_LOG(log, "Frame #0 not recognized");
+    return;
+  }
+
+  if (StackFrameSP most_relevant_frame_sp =
+          recognized_frame_sp->GetMostRelevantFrame()) {
+    LLDB_LOG(log, "Found most relevant frame at index {0}",
+             most_relevant_frame_sp->GetFrameIndex());
+    SetSelectedFrame(most_relevant_frame_sp.get());
+  } else {
+    LLDB_LOG(log, "No relevant frame!");
+  }
+}
+
+uint32_t StackFrameList::GetSelectedFrameIndex(
+    SelectMostRelevant select_most_relevant) {
   std::lock_guard<std::recursive_mutex> guard(m_mutex);
-  return m_selected_frame_idx;
+  if (!m_selected_frame_idx && select_most_relevant)
+    SelectMostRelevantFrame();
+  if (!m_selected_frame_idx) {
+    // If we aren't selecting the most relevant frame, and the selected frame
+    // isn't set, then don't force a selection here, just return 0.
+    if (!select_most_relevant)
+      return 0;
+    m_selected_frame_idx = 0;
+  }
+  return *m_selected_frame_idx;
 }
 
 uint32_t StackFrameList::SetSelectedFrame(lldb_private::StackFrame *frame) {
@@ -783,17 +851,19 @@ uint32_t StackFrameList::SetSelectedFrame(lldb_private::StackFrame *frame) {
   const_iterator begin = m_frames.begin();
   const_iterator end = m_frames.end();
   m_selected_frame_idx = 0;
+
   for (pos = begin; pos != end; ++pos) {
     if (pos->get() == frame) {
       m_selected_frame_idx = std::distance(begin, pos);
       uint32_t inlined_depth = GetCurrentInlinedDepth();
       if (inlined_depth != UINT32_MAX)
-        m_selected_frame_idx -= inlined_depth;
+        m_selected_frame_idx = *m_selected_frame_idx - inlined_depth;
       break;
     }
   }
+
   SetDefaultFileAndLineToSelectedFrame();
-  return m_selected_frame_idx;
+  return *m_selected_frame_idx;
 }
 
 bool StackFrameList::SetSelectedFrameByIndex(uint32_t idx) {
@@ -809,7 +879,8 @@ bool StackFrameList::SetSelectedFrameByIndex(uint32_t idx) {
 void StackFrameList::SetDefaultFileAndLineToSelectedFrame() {
   if (m_thread.GetID() ==
       m_thread.GetProcess()->GetThreadList().GetSelectedThread()->GetID()) {
-    StackFrameSP frame_sp(GetFrameAtIndex(GetSelectedFrameIndex()));
+    StackFrameSP frame_sp(
+        GetFrameAtIndex(GetSelectedFrameIndex(DoNoSelectMostRelevantFrame)));
     if (frame_sp) {
       SymbolContext sc = frame_sp->GetSymbolContext(eSymbolContextLineEntry);
       if (sc.line_entry.file)
@@ -821,10 +892,16 @@ void StackFrameList::SetDefaultFileAndLineToSelectedFrame() {
 
 // The thread has been run, reset the number stack frames to zero so we can
 // determine how many frames we have lazily.
+// Note, we don't actually re-use StackFrameLists, we always make a new
+// StackFrameList every time we stop, and then copy frame information frame
+// by frame from the old to the new StackFrameList.  So the comment above,
+// does not describe how StackFrameLists are currently used.
+// Clear is currently only used to clear the list in the destructor.
 void StackFrameList::Clear() {
   std::lock_guard<std::recursive_mutex> guard(m_mutex);
   m_frames.clear();
   m_concrete_frames_fetched = 0;
+  m_selected_frame_idx.reset();
 }
 
 lldb::StackFrameSP
@@ -863,7 +940,8 @@ size_t StackFrameList::GetStatus(Stream &strm, uint32_t first_frame,
   else
     last_frame = first_frame + num_frames;
 
-  StackFrameSP selected_frame_sp = m_thread.GetSelectedFrame();
+  StackFrameSP selected_frame_sp =
+      m_thread.GetSelectedFrame(DoNoSelectMostRelevantFrame);
   const char *unselected_marker = nullptr;
   std::string buffer;
   if (selected_frame_marker) {
@@ -884,6 +962,14 @@ size_t StackFrameList::GetStatus(Stream &strm, uint32_t first_frame,
       else
         marker = unselected_marker;
     }
+    // Check for interruption here.  If we're fetching arguments, this loop
+    // can go slowly:
+    Debugger &dbg = m_thread.GetProcess()->GetTarget().GetDebugger();
+    if (INTERRUPT_REQUESTED(dbg, 
+          "Interrupted dumping stack for thread {0:hex} with {1} shown.",
+          m_thread.GetID(), num_frames_displayed))
+      break;
+
 
     if (!frame_sp->GetStatus(strm, show_frame_info,
                              num_frames_with_source > (first_frame - frame_idx),