[wasm] Generate source position information

src/compiler/source-position.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_SOURCE_POSITION_H_
 #define V8_COMPILER_SOURCE_POSITION_H_
 
 #include "src/assembler.h"
 #include "src/compiler/node-aux-data.h"
 
@@ skipping 56 matching lines @@
 
   explicit SourcePositionTable(Graph* graph);
   ~SourcePositionTable() {
     if (decorator_) RemoveDecorator();
   }
 
   void AddDecorator();
   void RemoveDecorator();
 
   SourcePosition GetSourcePosition(Node* node) const;
 

[Michael Starzinger, 2016/04/22 11:30:21]

nit: Drop empty newline between getter and setter for readability.

[Clemens Hammacher, 2016/04/22 13:46:40]

It's already there (getter on line 76, setter on 78)? ;)

+  void SetSourcePosition(Node* node, SourcePosition position);
+
+  Graph* GetGraph() const { return graph_; }

[Michael Starzinger, 2016/04/22 11:30:21]

nit: s/GetGraph/graph/ for this simple accessor. Also AFAICT the getter is only
needed for a DCHECK. I cannot judge the importance of the DCHECK, but if its
importance is negligible then I would vote for also dropping this getter.

[Clemens Hammacher, 2016/04/22 13:46:40]

OK, dropped it.

+
   void Print(std::ostream& os) const;
 
  private:
   class Decorator;
 
   Graph* const graph_;
   Decorator* decorator_;
   SourcePosition current_position_;
   NodeAuxData<SourcePosition> table_;
 
   DISALLOW_COPY_AND_ASSIGN(SourcePositionTable);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_SOURCE_POSITION_H_