Add new FrameArray type

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index b7c67030c5076332dc2bc2d2e24cf2804078b0e1..2d90acdb1d73c3c1dec43b900b20e5796290a8c2 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -76,6 +76,7 @@
 //       - BytecodeArray
 //       - FixedArray
 //         - DescriptorArray
+//         - FrameArray
 //         - LiteralsArray
 //         - HashTable
 //           - Dictionary
@@ -862,7 +863,7 @@ enum class ComparisonResult {
   INLINE(static type* cast(Object* object));            \
   INLINE(static const type* cast(const Object* object));
 
-
+class AbstractCode;
 class AccessorPair;
 class AllocationSite;
 class AllocationSiteCreationContext;
@@ -961,6 +962,7 @@ template <class C> inline bool Is(Object* obj);
   V(JSGeneratorObject)           \
   V(Map)                         \
   V(DescriptorArray)             \
+  V(FrameArray)                  \
   V(TransitionArray)             \
   V(LiteralsArray)               \
   V(TypeFeedbackMetadata)        \
@@ -2895,7 +2897,6 @@ class WeakFixedArray : public FixedArray {
   DISALLOW_IMPLICIT_CONSTRUCTORS(WeakFixedArray);
 };
 
-
 // Generic array grows dynamically with O(1) amortized insertion.
 class ArrayList : public FixedArray {
  public:
@@ -2925,6 +2926,76 @@ class ArrayList : public FixedArray {
   DISALLOW_IMPLICIT_CONSTRUCTORS(ArrayList);
 };
 
+#define FRAME_ARRAY_FIELD_LIST(V) \
+  V(WasmObject, Object)           \
+  V(WasmFunctionIndex, Smi)       \
+  V(Receiver, Object)             \
+  V(Function, JSFunction)         \
+  V(Code, AbstractCode)           \
+  V(Offset, Smi)
+
+// Container object for data collected during simple stack trace captures.
+class FrameArray : public FixedArray {
+ public:
+#define DECLARE_FRAME_ARRAY_ACCESSORS(name, type) \
+  inline type* name(int frame_ix) const;          \
+  inline void Set##name(int frame_ix, type* value);
+  FRAME_ARRAY_FIELD_LIST(DECLARE_FRAME_ARRAY_ACCESSORS)
+#undef DECLARE_FRAME_ARRAY_ACCESSORS
+
+  inline void SetSloppyFrameCount(int count);
+  inline int SloppyFrameCount() const;
+
+  inline bool IsWasmFrame(int frame_ix) const;
+  inline int FrameCount() const;
+
+  void ShrinkToFit();
+
+  static Handle<FrameArray> AppendJSFrame(Handle<FrameArray> in,
+                                          Handle<Object> receiver,
+                                          Handle<JSFunction> function,
+                                          Handle<AbstractCode> code,
+                                          int offset);
+  static Handle<FrameArray> AppendWasmFrame(Handle<FrameArray> in,
+                                            Handle<Object> wasm_object,
+                                            int wasm_function_index,
+                                            Handle<AbstractCode> code,
+                                            int offset);
+
+  DECLARE_CAST(FrameArray)
+
+ private:
+  // The underlying fixed array embodies a captured stack trace. The number of
+  // sloppy frames is stored at array[kFirstIndex]. Frame i occupies indices
+  // kFirstIndex + 1 + [i * kElementsPerFrame, (i + 1) * kElementsPerFrame[,
+  // with internal offsets as below:
+
+  static const int kWasmObjectOffset = 0;
+  static const int kWasmFunctionIndexOffset = 1;
+
+  static const int kReceiverOffset = 0;
+  static const int kFunctionOffset = 1;
+
+  static const int kCodeOffset = 2;
+  static const int kOffsetOffset = 3;
+
+  static const int kElementsPerFrame = 4;
+
+  // Array layout indices.
+
+  static const int kFrameCountIndex = 0;
+  static const int kSloppyFramesIndex = 1;
+  static const int kFirstIndex = 2;
+
+  static int LengthFor(int frame_count) {
+    return kFirstIndex + frame_count * kElementsPerFrame;
+  }
+
+  static Handle<FrameArray> EnsureSpace(Handle<FrameArray> array, int length);
+
+  friend class Factory;
+  DISALLOW_IMPLICIT_CONSTRUCTORS(FrameArray);
+};
 
 // DescriptorArrays are fixed arrays used to hold instance descriptors.
 // The format of the these objects is: