[profiler] Fix attribution for the top-most interpreted frame.

src/frames.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/frames.h"
 
 #include <memory>
 #include <sstream>
 
 #include "src/base/bits.h"
@@ skipping 164 matching lines @@
 }
 
 void StackTraceFrameIterator::AdvanceToArgumentsFrame() {
   if (!is_javascript() || !javascript_frame()->has_adapted_arguments()) return;
   iterator_.Advance();
   DCHECK(iterator_.frame()->is_arguments_adaptor());
 }
 
 // -------------------------------------------------------------------------
 
+namespace {
+
+bool IsInterpreterFramePc(Isolate* isolate, Address pc) {
+  Code* interpreter_entry_trampoline =
+      isolate->builtins()->builtin(Builtins::kInterpreterEntryTrampoline);
+  Code* interpreter_bytecode_advance =
+      isolate->builtins()->builtin(Builtins::kInterpreterEnterBytecodeAdvance);
+  Code* interpreter_bytecode_dispatch =
+      isolate->builtins()->builtin(Builtins::kInterpreterEnterBytecodeDispatch);
+
+  return (pc >= interpreter_entry_trampoline->instruction_start() &&
+          pc < interpreter_entry_trampoline->instruction_end()) ||
+         (pc >= interpreter_bytecode_advance->instruction_start() &&
+          pc < interpreter_bytecode_advance->instruction_end()) ||
+         (pc >= interpreter_bytecode_dispatch->instruction_start() &&
+          pc < interpreter_bytecode_dispatch->instruction_end());
+}
+
+DISABLE_ASAN Address ReadMemoryAt(Address address) {
+  return Memory::Address_at(address);
+}
+
+}  // namespace
 
 SafeStackFrameIterator::SafeStackFrameIterator(
     Isolate* isolate,
     Address fp, Address sp, Address js_entry_sp)
     : StackFrameIteratorBase(isolate, false),
       low_bound_(sp),
       high_bound_(js_entry_sp),
       top_frame_type_(StackFrame::NONE),
       external_callback_scope_(isolate->external_callback_scope()) {
   StackFrame::State state;
   StackFrame::Type type;
   ThreadLocalTop* top = isolate->thread_local_top();
+  bool advance_frame = true;
   if (IsValidTop(top)) {
     type = ExitFrame::GetStateForFramePointer(Isolate::c_entry_fp(top), &state);
     top_frame_type_ = type;
   } else if (IsValidStackAddress(fp)) {
     DCHECK(fp != NULL);
     state.fp = fp;
     state.sp = sp;
     state.pc_address = StackFrame::ResolveReturnAddressLocation(
         reinterpret_cast<Address*>(StandardFrame::ComputePCAddress(fp)));
+
+    // If the top of stack is a return address to the interpreter trampoline,
+    // then we are likely in a bytecode handler with elided frame. In that
+    // case, set the PC properly and make sure we do not drop the frame.
+    if (IsValidStackAddress(sp)) {
+      MSAN_MEMORY_IS_INITIALIZED(sp, kPointerSize);
+      Address tos = ReadMemoryAt(reinterpret_cast<Address>(sp));
+      if (IsInterpreterFramePc(isolate, tos)) {
+        state.pc_address = reinterpret_cast<Address*>(sp);
+        advance_frame = false;
+      }
+    }
+
     // StackFrame::ComputeType will read both kContextOffset and kMarkerOffset,
     // we check only that kMarkerOffset is within the stack bounds and do
     // compile time check that kContextOffset slot is pushed on the stack before
     // kMarkerOffset.
     STATIC_ASSERT(StandardFrameConstants::kFunctionOffset <
                   StandardFrameConstants::kContextOffset);
     Address frame_marker = fp + StandardFrameConstants::kFunctionOffset;
     if (IsValidStackAddress(frame_marker)) {
       type = StackFrame::ComputeType(this, &state);
       top_frame_type_ = type;
+      // We only keep the top frame if we believe it to be interpreted frame.
+      if (type != StackFrame::INTERPRETED) {
+        advance_frame = true;
+      }
     } else {
       // Mark the frame as JAVA_SCRIPT if we cannot determine its type.
       // The frame anyways will be skipped.
       type = StackFrame::JAVA_SCRIPT;
       // Top frame is incomplete so we cannot reliably determine its type.
       top_frame_type_ = StackFrame::NONE;
     }
   } else {
     return;
   }
   frame_ = SingletonFor(type, &state);
-  if (frame_) Advance();
+  if (advance_frame && frame_) Advance();
 }
 
 
 bool SafeStackFrameIterator::IsValidTop(ThreadLocalTop* top) const {
   Address c_entry_fp = Isolate::c_entry_fp(top);
   if (!IsValidExitFrame(c_entry_fp)) return false;
   // There should be at least one JS_ENTRY stack handler.
   Address handler = Isolate::handler(top);
   if (handler == NULL) return false;
   // Check that there are no js frames on top of the native frames.
@@ skipping 144 matching lines @@
   }
 }
 
 
 void StackFrame::SetReturnAddressLocationResolver(
     ReturnAddressLocationResolver resolver) {
   DCHECK(return_address_location_resolver_ == NULL);
   return_address_location_resolver_ = resolver;
 }
 
-static bool IsInterpreterFramePc(Isolate* isolate, Address pc) {
-  Code* interpreter_entry_trampoline =
-      isolate->builtins()->builtin(Builtins::kInterpreterEntryTrampoline);
-  Code* interpreter_bytecode_advance =
-      isolate->builtins()->builtin(Builtins::kInterpreterEnterBytecodeAdvance);
-  Code* interpreter_bytecode_dispatch =
-      isolate->builtins()->builtin(Builtins::kInterpreterEnterBytecodeDispatch);
-
-  return (pc >= interpreter_entry_trampoline->instruction_start() &&
-          pc < interpreter_entry_trampoline->instruction_end()) ||
-         (pc >= interpreter_bytecode_advance->instruction_start() &&
-          pc < interpreter_bytecode_advance->instruction_end()) ||
-         (pc >= interpreter_bytecode_dispatch->instruction_start() &&
-          pc < interpreter_bytecode_dispatch->instruction_end());
-}
-
 StackFrame::Type StackFrame::ComputeType(const StackFrameIteratorBase* iterator,
                                          State* state) {
   DCHECK(state->fp != NULL);
 
   MSAN_MEMORY_IS_INITIALIZED(
       state->fp + CommonFrameConstants::kContextOrFrameTypeOffset,
       kPointerSize);
   Object* marker = Memory::Object_at(
       state->fp + CommonFrameConstants::kContextOrFrameTypeOffset);
   if (!iterator->can_access_heap_objects_) {
@@ skipping 1819 matching lines @@
   for (StackFrameIterator it(isolate); !it.done(); it.Advance()) {
     StackFrame* frame = AllocateFrameCopy(it.frame(), zone);
     list.Add(frame, zone);
   }
   return list.ToVector();
 }
 
 
 }  // namespace internal
 }  // namespace v8