[interpreter, debugger] abstraction for source position calculation.

src/heap/heap.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/heap/heap.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/ast/scopeinfo.h"
 #include "src/base/bits.h"
@@ skipping 754 matching lines @@
   FixedArray* elements;
   while ((elements = iterator.Next<FixedArray>())) {
     for (int j = 1; j < elements->length(); j += 4) {
       Object* maybe_code = elements->get(j + 2);
       // If GC happens while adding a stack trace to the weak fixed array,
       // which has been copied into a larger backing store, we may run into
       // a stack trace that has already been preprocessed. Guard against this.
       if (!maybe_code->IsCode()) break;
       Code* code = Code::cast(maybe_code);
       int offset = Smi::cast(elements->get(j + 3))->value();
-      Address pc = code->address() + offset;
-      int pos = code->SourcePosition(pc);
+      int pos = code->SourcePosition(offset);
       elements->set(j + 2, Smi::FromInt(pos));
     }
   }
   // We must not compact the weak fixed list here, as we may be in the middle
   // of writing to it, when the GC triggered. Instead, we reset the root value.
   set_weak_stack_trace_list(Smi::FromInt(0));
 }
 
 
 class GCCallbacksScope {
@@ skipping 5435 matching lines @@
 }
 
 
 // static
 int Heap::GetStaticVisitorIdForMap(Map* map) {
   return StaticVisitorBase::GetVisitorId(map);
 }
 
 }  // namespace internal
 }  // namespace v8