[wasm] [cleanup] Use correct type more consistently

For more static type safety: Avoid passing wasm objects as Object and
casting them before use. Use the correct type right away.

R=ahaas@chromium.org
BUG=v8:6474

Change-Id: Id0c486560115dd1a7bd9b6a12d2fb938e06520ef
Reviewed-on: https://chromium-review.googlesource.com/530744Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45838}

src/messages.cc

@@ -653,15 +653,15 @@ void WasmStackFrame::FromFrameArray(Isolate* isolate, Handle<FrameArray> array,
   offset_ = array->Offset(frame_ix)->value();
 }
 
+Handle<Object> WasmStackFrame::GetReceiver() const { return wasm_instance_; }
+
 Handle<Object> WasmStackFrame::GetFunction() const {
-  Handle<Object> obj(Smi::FromInt(wasm_func_index_), isolate_);
-  return obj;
+  return handle(Smi::FromInt(wasm_func_index_), isolate_);
 }
 
 Handle<Object> WasmStackFrame::GetFunctionName() {
   Handle<Object> name;
-  Handle<WasmCompiledModule> compiled_module(
-      Handle<WasmInstanceObject>::cast(wasm_instance_)->compiled_module(),
+  Handle<WasmCompiledModule> compiled_module(wasm_instance_->compiled_module(),
                                              isolate_);
   if (!WasmCompiledModule::GetFunctionNameOrNull(isolate_, compiled_module,
                                                  wasm_func_index_)

src/messages.h

@@ -25,6 +25,7 @@ class JSMessageObject;
 class LookupIterator;
 class SharedFunctionInfo;
 class SourceInfo;
+class WasmInstanceObject;
 
 class MessageLocation {
  public:
@@ -132,7 +133,7 @@ class WasmStackFrame : public StackFrameBase {
  public:
   virtual ~WasmStackFrame() {}
 
-  Handle<Object> GetReceiver() const override { return wasm_instance_; }
+  Handle<Object> GetReceiver() const override;
   Handle<Object> GetFunction() const override;
 
   Handle<Object> GetFileName() override { return Null(); }
@@ -159,8 +160,7 @@ class WasmStackFrame : public StackFrameBase {
   bool HasScript() const override;
   Handle<Script> GetScript() const override;
 
-  // TODO(wasm): Use proper typing.
-  Handle<Object> wasm_instance_;
+  Handle<WasmInstanceObject> wasm_instance_;
   uint32_t wasm_func_index_;
   Handle<AbstractCode> code_;  // null handle for interpreted frames.
   int offset_;

src/objects.cc

@@ -10117,11 +10117,9 @@ Handle<FrameArray> FrameArray::AppendJSFrame(Handle<FrameArray> in,
 }
 
 // static
-Handle<FrameArray> FrameArray::AppendWasmFrame(Handle<FrameArray> in,
-                                               Handle<Object> wasm_instance,
-                                               int wasm_function_index,
-                                               Handle<AbstractCode> code,
-                                               int offset, int flags) {
+Handle<FrameArray> FrameArray::AppendWasmFrame(
+    Handle<FrameArray> in, Handle<WasmInstanceObject> wasm_instance,
+    int wasm_function_index, Handle<AbstractCode> code, int offset, int flags) {
   const int frame_count = in->FrameCount();
   const int new_length = LengthFor(frame_count + 1);
   Handle<FrameArray> array = EnsureSpace(in, new_length);

src/objects/frame-array.h

@@ -6,6 +6,7 @@
 #define V8_OBJECTS_FRAME_ARRAY_H_
 
 #include "src/objects.h"
+#include "src/wasm/wasm-objects.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"
@@ -17,7 +18,7 @@ template <typename T>
 class Handle;
 
 #define FRAME_ARRAY_FIELD_LIST(V)     \
-  V(WasmInstance, Object)         \
+  V(WasmInstance, WasmInstanceObject) \
   V(WasmFunctionIndex, Smi)           \
   V(Receiver, Object)                 \
   V(Function, JSFunction)             \
@@ -56,11 +57,10 @@ class FrameArray : public FixedArray {
                                           Handle<JSFunction> function,
                                           Handle<AbstractCode> code, int offset,
                                           int flags);
-  static Handle<FrameArray> AppendWasmFrame(Handle<FrameArray> in,
-                                            Handle<Object> wasm_instance,
-                                            int wasm_function_index,
-                                            Handle<AbstractCode> code,
-                                            int offset, int flags);
+  static Handle<FrameArray> AppendWasmFrame(
+      Handle<FrameArray> in, Handle<WasmInstanceObject> wasm_instance,
+      int wasm_function_index, Handle<AbstractCode> code, int offset,
+      int flags);
 
   DECLARE_CAST(FrameArray)