More simplification and unification of frame handling

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 <sstream>
 
 #include "src/ast/ast.h"
 #include "src/ast/scopeinfo.h"
@@ skipping 624 matching lines @@
 void StandardFrame::IterateCompiledFrame(ObjectVisitor* v) const {
   // Make sure that we're not doing "safe" stack frame iteration. We cannot
   // possibly find pointers in optimized frames in that state.
   DCHECK(can_access_heap_objects());
 
   // Compute the safepoint information.
   unsigned stack_slots = 0;
   SafepointEntry safepoint_entry;
   Code* code = StackFrame::GetSafepointData(
       isolate(), pc(), &safepoint_entry, &stack_slots);
-  unsigned slot_space = stack_slots * kPointerSize;
+  unsigned slot_space =
+      stack_slots * kPointerSize - StandardFrameConstants::kFixedFrameSize;
 
   // Visit the outgoing parameters.
   Object** parameters_base = &Memory::Object_at(sp());
   Object** parameters_limit = &Memory::Object_at(
       fp() + JavaScriptFrameConstants::kFunctionOffset - slot_space);
 
   // Visit the parameters that may be on top of the saved registers.
   if (safepoint_entry.argument_count() > 0) {
     v->VisitPointers(parameters_base,
                      parameters_base + safepoint_entry.argument_count());
@@ skipping 983 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