Deoptimize context value in Turbofan (and Crankshaft).

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/v8.h"
 
 #include "src/accessors.h"
 #include "src/codegen.h"
 #include "src/deoptimizer.h"
 #include "src/disasm.h"
@@ skipping 908 matching lines @@
   BailoutId node_id = BailoutId(iterator->Next());
   JSFunction* function;
   if (frame_index != 0) {
     function = JSFunction::cast(ComputeLiteral(iterator->Next()));
   } else {
     int closure_id = iterator->Next();
     USE(closure_id);
     CHECK_EQ(Translation::kSelfLiteralId, closure_id);
     function = function_;
   }
-  unsigned height = iterator->Next();
+  unsigned height = iterator->Next() - 1;  // Do not count the context.
   unsigned height_in_bytes = height * kPointerSize;
   if (trace_scope_ != NULL) {
     PrintF(trace_scope_->file(), "  translating ");
     function->PrintName(trace_scope_->file());
     PrintF(trace_scope_->file(),
            " => node=%d, height=%d\n", node_id.ToInt(), height_in_bytes);
   }
 
   // The 'fixed' part of the frame consists of the incoming parameters and
   // the part described by JavaScriptFrameConstants.
@@ skipping 114 matching lines @@
              top_address + output_offset, output_offset, value);
     }
   }
 
   // For the bottommost output frame the context can be gotten from the input
   // frame. For all subsequent output frames it can be gotten from the function
   // so long as we don't inline functions that need local contexts.
   Register context_reg = JavaScriptFrame::context_register();
   output_offset -= kPointerSize;
   input_offset -= kPointerSize;
-  if (is_bottommost) {
-    value = input_->GetFrameSlot(input_offset);
-  } else {
-    value = reinterpret_cast<intptr_t>(function->context());
-  }
-  output_frame->SetFrameSlot(output_offset, value);
+  // Read the context from the translations.
+  DoTranslateCommand(iterator, frame_index, output_offset);
+  value = output_frame->GetFrameSlot(output_offset);
+  // The context should not be a placeholder for a materialized object.
+  CHECK(value !=
+        reinterpret_cast<intptr_t>(isolate_->heap()->arguments_marker()));
   output_frame->SetContext(value);
   if (is_topmost) output_frame->SetRegister(context_reg.code(), value);
   if (trace_scope_ != NULL) {
     PrintF(trace_scope_->file(),
            "    0x%08" V8PRIxPTR ": [top + %d] <- 0x%08"
            V8PRIxPTR "; context\n",
            top_address + output_offset, output_offset, value);
   }
 
   // The function was mentioned explicitly in the BEGIN_FRAME.
@@ skipping 2543 matching lines @@
   return new_array;
 }
 
 
 DeoptimizedFrameInfo::DeoptimizedFrameInfo(Deoptimizer* deoptimizer,
                                            int frame_index,
                                            bool has_arguments_adaptor,
                                            bool has_construct_stub) {
   FrameDescription* output_frame = deoptimizer->output_[frame_index];
   function_ = output_frame->GetFunction();
+  context_ = reinterpret_cast<Object*>(output_frame->GetContext());
   has_construct_stub_ = has_construct_stub;
   expression_count_ = output_frame->GetExpressionCount();
   expression_stack_ = new Object*[expression_count_];
   // Get the source position using the unoptimized code.
   Address pc = reinterpret_cast<Address>(output_frame->GetPc());
   Code* code = Code::cast(deoptimizer->isolate()->FindCodeObject(pc));
   source_position_ = code->SourcePosition(pc);
 
   for (int i = 0; i < expression_count_; i++) {
     SetExpression(i, output_frame->GetExpression(i));
@@ skipping 13 matching lines @@
 
 
 DeoptimizedFrameInfo::~DeoptimizedFrameInfo() {
   delete[] expression_stack_;
   delete[] parameters_;
 }
 
 
 void DeoptimizedFrameInfo::Iterate(ObjectVisitor* v) {
   v->VisitPointer(BitCast<Object**>(&function_));
+  v->VisitPointer(&context_);
   v->VisitPointers(parameters_, parameters_ + parameters_count_);
   v->VisitPointers(expression_stack_, expression_stack_ + expression_count_);
 }
 
 } }  // namespace v8::internal