[deoptimizer] Fix for non-topmost interpreted frame.

src/deoptimizer.cc

 // Copyright 2013 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/deoptimizer.h"
 
 #include <memory>
 
 #include "src/accessors.h"
 #include "src/ast/prettyprinter.h"
@@ skipping 1064 matching lines @@
         reinterpret_cast<intptr_t>(continuation->entry()));
   }
 }
 
 void Deoptimizer::DoComputeInterpretedFrame(TranslatedFrame* translated_frame,
                                             int frame_index,
                                             bool goto_catch_handler) {
   SharedFunctionInfo* shared = translated_frame->raw_shared_info();
 
   TranslatedFrame::iterator value_iterator = translated_frame->begin();
+  bool is_bottommost = (0 == frame_index);
+  bool is_topmost = (output_count_ - 1 == frame_index);
   int input_index = 0;
 
   int bytecode_offset = translated_frame->node_id().ToInt();
   unsigned height = translated_frame->height();
   unsigned height_in_bytes = height * kPointerSize;
   JSFunction* function = JSFunction::cast(value_iterator->GetRawValue());
   value_iterator++;
   input_index++;
   if (trace_scope_ != NULL) {
     PrintF(trace_scope_->file(), "  translating interpreted frame ");
     std::unique_ptr<char[]> name = shared->DebugName()->ToCString();
     PrintF(trace_scope_->file(), "%s", name.get());
     PrintF(trace_scope_->file(), " => bytecode_offset=%d, height=%d%s\n",
            bytecode_offset, height_in_bytes,
            goto_catch_handler ? " (throw)" : "");
   }
   if (goto_catch_handler) {
     bytecode_offset = catch_handler_pc_offset_;
   }
 
+  // All tranlations for interpreted frames contain the accumulator and hence
+  // are assumed to be in bailout state {BailoutState::TOS_REGISTER}. However
+  // such a state is only supported for the topmost frame. We need to skip
+  // pushing the accumulator for any non-topmost frame.
+  if (!is_topmost) height_in_bytes -= kPointerSize;

[rmcilroy, 2016/08/24 11:18:30]

Should we do this before printing height for the trace_scope_ != NULL case
above?

[Michael Starzinger, 2016/08/24 11:38:42]

Done. No strong opinion either way.

+
   // The 'fixed' part of the frame consists of the incoming parameters and
   // the part described by InterpreterFrameConstants.
   unsigned fixed_frame_size = ComputeInterpretedFixedSize(shared);
   unsigned output_frame_size = height_in_bytes + fixed_frame_size;
 
   // Allocate and store the output frame description.
   int parameter_count = shared->internal_formal_parameter_count() + 1;
   FrameDescription* output_frame = new (output_frame_size)
       FrameDescription(output_frame_size, parameter_count);
   output_frame->SetFrameType(StackFrame::INTERPRETED);
 
-  bool is_bottommost = (0 == frame_index);
-  bool is_topmost = (output_count_ - 1 == frame_index);
   CHECK(frame_index >= 0 && frame_index < output_count_);
   CHECK_NULL(output_[frame_index]);
   output_[frame_index] = output_frame;
 
   // The top address of the frame is computed from the previous frame's top and
   // this frame's size.
   intptr_t top_address;
   if (is_bottommost) {
     top_address = caller_frame_top_ - output_frame_size;
   } else {
@@ skipping 120 matching lines @@
   WriteValueToOutput(smi_bytecode_offset, 0, frame_index, output_offset,
                      "bytecode offset ");
 
   // Translate the rest of the interpreter registers in the frame.
   for (unsigned i = 0; i < height - 1; ++i) {
     output_offset -= kPointerSize;
     WriteTranslatedValueToOutput(&value_iterator, &input_index, frame_index,
                                  output_offset);
   }
 
-  // Put the accumulator on the stack. It will be popped by the
-  // InterpreterNotifyDeopt builtin (possibly after materialization).
-  output_offset -= kPointerSize;
-  if (goto_catch_handler) {
-    // If we are lazy deopting to a catch handler, we set the accumulator to
-    // the exception (which lives in the result register).
-    intptr_t accumulator_value =
-        input_->GetRegister(FullCodeGenerator::result_register().code());
-    WriteValueToOutput(reinterpret_cast<Object*>(accumulator_value), 0,
-                       frame_index, output_offset, "accumulator ");
+  // Put the accumulator on the stack. The bailout state for interpreted frames
+  // is always set to {BailoutState::TOS_REGISTER} and the {NotifyDeoptimized}
+  // builtin will pop it off the topmost frame (possibly after materialization).
+  if (is_topmost) {
+    output_offset -= kPointerSize;
+    if (goto_catch_handler) {
+      // If we are lazy deopting to a catch handler, we set the accumulator to
+      // the exception (which lives in the result register).
+      intptr_t accumulator_value =
+          input_->GetRegister(FullCodeGenerator::result_register().code());
+      WriteValueToOutput(reinterpret_cast<Object*>(accumulator_value), 0,
+                         frame_index, output_offset, "accumulator ");
+      value_iterator++;
+    } else {
+      WriteTranslatedValueToOutput(&value_iterator, &input_index, frame_index,
+                                   output_offset);
+    }
+  } else {
     value_iterator++;
-  } else {
-    WriteTranslatedValueToOutput(&value_iterator, &input_index, frame_index,
-                                 output_offset);
+    input_index++;
   }
   CHECK_EQ(0u, output_offset);
 
   Builtins* builtins = isolate_->builtins();
   Code* dispatch_builtin =
       builtins->builtin(Builtins::kInterpreterEnterBytecodeDispatch);
   output_frame->SetPc(reinterpret_cast<intptr_t>(dispatch_builtin->entry()));
   // Restore accumulator (TOS) register.
   output_frame->SetState(
       Smi::FromInt(static_cast<int>(BailoutState::TOS_REGISTER)));
@@ skipping 2726 matching lines @@
       CHECK(value_info->IsMaterializedObject());
 
       value_info->value_ =
           Handle<Object>(previously_materialized_objects->get(i), isolate_);
     }
   }
 }
 
 }  // namespace internal
 }  // namespace v8