Track the 'awaiter return' call stack use it to detect uncaught exceptions in async functions

runtime/vm/debugger.h

Index: runtime/vm/debugger.h
diff --git a/runtime/vm/debugger.h b/runtime/vm/debugger.h
index bf932feb31e18e883c1f587416453068f129b081..206616ab707890e430dae5ec9451db599e6ae2af 100644
--- a/runtime/vm/debugger.h
+++ b/runtime/vm/debugger.h
@@ -260,6 +260,7 @@ class ActivationFrame : public ZoneAllocated {
     kRegular,
     kAsyncSuspensionMarker,
     kAsyncCausal,
+    kAsyncActivation,
   };
 
   ActivationFrame(uword pc,
@@ -274,6 +275,8 @@ class ActivationFrame : public ZoneAllocated {
 
   explicit ActivationFrame(Kind kind);
 
+  explicit ActivationFrame(const Closure& async_activation);
+
   uword pc() const { return pc_; }
   uword fp() const { return fp_; }
   uword sp() const { return sp_; }
@@ -332,6 +335,10 @@ class ActivationFrame : public ZoneAllocated {
   // the complete script, function, and, local variable objects are included.
   void PrintToJSONObject(JSONObject* jsobj, bool full = false);
 
+  RawObject* GetAsyncAwaiter();
+
+  bool HandlesException(const Instance& exc_obj);
+
  private:
   void PrintToJSONObjectRegular(JSONObject* jsobj, bool full);
   void PrintToJSONObjectAsyncCausal(JSONObject* jsobj, bool full);
@@ -346,6 +353,12 @@ class ActivationFrame : public ZoneAllocated {
   void GetVarDescriptors();
   void GetDescIndices();
 
+  RawObject* GetAsyncStreamControllerStreamAwaiter(const Object& stream);
+  RawObject* GetAsyncStreamControllerStream();
+  RawObject* GetAsyncCompleterAwaiter(const Object& completer);
+  RawObject* GetAsyncCompleter();
+  void ExtractTokenPositionFromAsyncClosure();
+
   static const char* KindToCString(Kind kind) {
     switch (kind) {
       case kRegular:
@@ -627,12 +640,14 @@ class Debugger {
   void SyncBreakpointLocation(BreakpointLocation* loc);
 
   ActivationFrame* TopDartFrame() const;
-  static ActivationFrame* CollectDartFrame(Isolate* isolate,
-                                           uword pc,
-                                           StackFrame* frame,
-                                           const Code& code,
-                                           const Array& deopt_frame,
-                                           intptr_t deopt_frame_offset);
+  static ActivationFrame* CollectDartFrame(
+      Isolate* isolate,
+      uword pc,
+      StackFrame* frame,
+      const Code& code,
+      const Array& deopt_frame,
+      intptr_t deopt_frame_offset,
+      ActivationFrame::Kind kind = ActivationFrame::kRegular);
   static RawArray* DeoptimizeToArray(Thread* thread,
                                      StackFrame* frame,
                                      const Code& code);
@@ -648,10 +663,14 @@ class Debugger {
                                Array* deopt_frame);
   static DebuggerStackTrace* CollectStackTrace();
   static DebuggerStackTrace* CollectAsyncCausalStackTrace();
+  static DebuggerStackTrace* CollectAwaiterReturnStackTrace();
   void SignalPausedEvent(ActivationFrame* top_frame, Breakpoint* bpt);
 
   intptr_t nextId() { return next_id_++; }
 
+  bool ShouldPauseOnAsyncException(DebuggerStackTrace* stack_trace,
+                                   const Instance& exc);
+
   bool ShouldPauseOnException(DebuggerStackTrace* stack_trace,
                               const Instance& exc);