Extend assembler with ability to produce comments for the generated code.

runtime/vm/assembler_x64.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_ASSEMBLER_X64_H_
 #define VM_ASSEMBLER_X64_H_
 
 #ifndef VM_ASSEMBLER_H_
 #error Do not include assembler_x64.h directly; use assembler.h instead.
 #endif
@@ skipping 278 matching lines @@
   int unresolved_;
   int unresolved_near_positions_[kMaxUnresolvedBranches];
 
   friend class Assembler;
   DISALLOW_COPY_AND_ASSIGN(Label);
 };
 
 
 class Assembler : public ValueObject {
  public:
-  Assembler() : buffer_(), prolog_offset_(-1) { }
+  Assembler() : buffer_(), prolog_offset_(-1), comments_() { }
   ~Assembler() { }
 
   static const bool kNearJump = true;
   static const bool kFarJump = false;
 
   /*
    * Emit Machine Instructions.
    */
   void call(Register reg);
   void call(const Address& address);
@@ skipping 213 matching lines @@
   }
 
   void SmiUntag(Register reg) {
     sarq(reg, Immediate(kSmiTagSize));
   }
 
   int PreferredLoopAlignment() { return 16; }
   void Align(int alignment, int offset);
   void Bind(Label* label);
 
+  void Comment(const char* format, ...);
+  const Code::Comments& GetCodeComments() const;
+
   int CodeSize() const { return buffer_.Size(); }
   int prolog_offset() const { return prolog_offset_; }
   const ZoneGrowableArray<int>& GetPointerOffsets() const {
     return buffer_.pointer_offsets();
   }
 
   void FinalizeInstructions(const MemoryRegion& region) {
     buffer_.FinalizeInstructions(region);
   }
 
   // Debugging and bringup support.
   void Stop(const char* message);
   void Unimplemented(const char* message);
   void Untested(const char* message);
   void Unreachable(const char* message);
 
   static void InitializeMemoryWithBreakpoints(uword data, int length);
 
  private:
   AssemblerBuffer buffer_;
   int prolog_offset_;
 
+  class CodeComment : public ZoneAllocated {
+   public:
+    CodeComment(intptr_t pc_offset, const String& comment)
+        : pc_offset_(pc_offset), comment_(comment) { }
+
+    intptr_t pc_offset() const { return pc_offset_; }
+    const String& comment() const { return comment_; }
+
+   private:
+    intptr_t pc_offset_;
+    const String& comment_;
+
+    DISALLOW_COPY_AND_ASSIGN(CodeComment);
+  };
+
+  GrowableArray<CodeComment*> comments_;
+
   inline void EmitUint8(uint8_t value);
   inline void EmitInt32(int32_t value);
   inline void EmitInt64(int64_t value);
 
   inline void EmitRegisterREX(Register reg, uint8_t rex);
   inline void EmitRegisterOperand(int rm, int reg);
   inline void EmitOperandREX(int rm, const Operand& operand, uint8_t rex);
   inline void EmitXmmRegisterOperand(int rm, XmmRegister reg);
   inline void EmitFixup(AssemblerFixup* fixup);
   inline void EmitOperandSizeOverride();
@@ skipping 48 matching lines @@
 }
 
 
 inline void Assembler::EmitOperandSizeOverride() {
   EmitUint8(0x66);
 }
 
 }  // namespace dart
 
 #endif  // VM_ASSEMBLER_X64_H_