[interpreter] Add field for source position table to byte code array.

R=mstarzinger@chromium.org
BUG=v8:4690
LOG=N

Review URL: https://codereview.chromium.org/1601813009

Cr-Commit-Position: refs/heads/master@{#33409}

src/heap/heap.cc

@@ -3057,6 +3057,7 @@ AllocationResult Heap::AllocateBytecodeArray(int length,
   instance->set_parameter_count(parameter_count);
   instance->set_constant_pool(constant_pool);
   instance->set_handler_table(empty_fixed_array());
+  instance->set_source_position_table(empty_fixed_array());
   CopyBytes(instance->GetFirstBytecodeAddress(), raw_bytecodes, length);
 
   return result;

src/objects-body-descriptors-inl.h

@@ -193,7 +193,8 @@ class JSArrayBuffer::BodyDescriptor final : public BodyDescriptorBase {
 class BytecodeArray::BodyDescriptor final : public BodyDescriptorBase {
  public:
   static bool IsValidSlot(HeapObject* obj, int offset) {
-    return offset == kConstantPoolOffset || offset == kHandlerTableOffset;
+    return offset >= kConstantPoolOffset &&
+           offset <= kSourcePositionTableOffset;
   }
 
   template <typename ObjectVisitor>
@@ -201,6 +202,7 @@ class BytecodeArray::BodyDescriptor final : public BodyDescriptorBase {
                                  ObjectVisitor* v) {
     IteratePointer(obj, kConstantPoolOffset, v);
     IteratePointer(obj, kHandlerTableOffset, v);
+    IteratePointer(obj, kSourcePositionTableOffset, v);
   }
 
   template <typename StaticVisitor>
@@ -208,6 +210,7 @@ class BytecodeArray::BodyDescriptor final : public BodyDescriptorBase {
     Heap* heap = obj->GetHeap();
     IteratePointer<StaticVisitor>(heap, obj, kConstantPoolOffset);
     IteratePointer<StaticVisitor>(heap, obj, kHandlerTableOffset);
+    IteratePointer<StaticVisitor>(heap, obj, kSourcePositionTableOffset);
   }
 
   static inline int SizeOf(Map* map, HeapObject* obj) {

src/objects-inl.h

@@ -4051,6 +4051,8 @@ int BytecodeArray::parameter_count() const {
 
 ACCESSORS(BytecodeArray, constant_pool, FixedArray, kConstantPoolOffset)
 ACCESSORS(BytecodeArray, handler_table, FixedArray, kHandlerTableOffset)
+ACCESSORS(BytecodeArray, source_position_table, FixedArray,
+          kSourcePositionTableOffset)
 
 
 Address BytecodeArray::GetFirstBytecodeAddress() {

src/objects.h

@@ -4379,6 +4379,10 @@ class BytecodeArray : public FixedArrayBase {
   // Accessors for handler table containing offsets of exception handlers.
   DECL_ACCESSORS(handler_table, FixedArray)
 
+  // Accessors for source position table containing mappings between byte code
+  // offset and source position.
+  DECL_ACCESSORS(source_position_table, FixedArray)
+
   DECLARE_CAST(BytecodeArray)
 
   // Dispatched behavior.
@@ -4394,7 +4398,9 @@ class BytecodeArray : public FixedArrayBase {
   static const int kParameterSizeOffset = kFrameSizeOffset + kIntSize;
   static const int kConstantPoolOffset = kParameterSizeOffset + kIntSize;
   static const int kHandlerTableOffset = kConstantPoolOffset + kPointerSize;
-  static const int kHeaderSize = kHandlerTableOffset + kPointerSize;
+  static const int kSourcePositionTableOffset =
+      kHandlerTableOffset + kPointerSize;
+  static const int kHeaderSize = kSourcePositionTableOffset + kPointerSize;
 
   static const int kAlignedSize = OBJECT_POINTER_ALIGN(kHeaderSize);