Better typing and type verification

src/compiler/typer.h

 // Copyright 2014 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.
 
 #ifndef V8_COMPILER_TYPER_H_
 #define V8_COMPILER_TYPER_H_
 
 #include "src/v8.h"
 
 #include "src/compiler/graph.h"
 #include "src/compiler/opcodes.h"
 #include "src/types.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 class Typer {
  public:
-  explicit Typer(Zone* zone);
+  explicit Typer(Graph* graph, MaybeHandle<Context> context);
+  ~Typer();
 
-  void Init(Node* node);
-  void Run(Graph* graph, MaybeHandle<Context> context);
-  void Narrow(Graph* graph, Node* node, MaybeHandle<Context> context);
-  void Widen(Graph* graph, Node* node, MaybeHandle<Context> context);
+  void Run();
+  void Narrow(Node* node);
 
-  void DecorateGraph(Graph* graph);
-
-  Zone* zone() { return zone_; }
-  Isolate* isolate() { return zone_->isolate(); }
+  Graph* graph() { return graph_; }
+  MaybeHandle<Context> context() { return context_; }
+  Zone* zone() { return graph_->zone(); }
+  Isolate* isolate() { return zone()->isolate(); }
 
  private:
   class Visitor;
   class RunVisitor;
   class NarrowVisitor;
   class WidenVisitor;
+  class Decorator;
 
-  Zone* zone_;
+  Graph* graph_;
+  MaybeHandle<Context> context_;
+  Decorator* decorator_;
+
   Type* number_fun0_;
   Type* number_fun1_;
   Type* number_fun2_;
   Type* imul_fun_;
   Type* array_buffer_fun_;
   Type* int8_array_fun_;
   Type* int16_array_fun_;
   Type* int32_array_fun_;
   Type* uint8_array_fun_;
   Type* uint16_array_fun_;
   Type* uint32_array_fun_;
   Type* float32_array_fun_;
   Type* float64_array_fun_;
 };
 }
 }
 }  // namespace v8::internal::compiler
 
 #endif  // V8_COMPILER_TYPER_H_