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

runtime/vm/object.h

Index: runtime/vm/object.h
diff --git a/runtime/vm/object.h b/runtime/vm/object.h
index c4be8a68f70a98f252c934a1395b47bceb965122..8103ea0dcd4835476b11b6a965b6a14c97d9b639 100644
--- a/runtime/vm/object.h
+++ b/runtime/vm/object.h
@@ -2143,6 +2143,34 @@ class ExceptionHandlers : public Object {
 };
 
 
+class CodeComments : public ValueObject {

[srdjan, 2012/05/17 17:22:08]

Please move CodeComments inside class Code.

[Vyacheslav Egorov (Google), 2012/05/17 21:16:27]

Done.

+ public:
+  enum {
+    kPCEntry = 0,
+    kCommentEntry,
+    kNumberOfEntries
+  };

[srdjan, 2012/05/17 17:22:08]

name the enum, and why do you need it?

[srdjan, 2012/05/17 17:22:08]

name the enum, and why do you need it?

[Vyacheslav Egorov (Google), 2012/05/17 21:16:27]

Discussed offline. Moved enum to private section. Added comments.

+
+  static CodeComments New(int count);

[srdjan, 2012/05/17 17:22:08]

Memory sizes are in intptr_t.

[Vyacheslav Egorov (Google), 2012/05/17 21:16:27]

Done.

+
+  intptr_t Length();
+
+  intptr_t PCAt(int idx);

[srdjan, 2012/05/17 17:22:08]

Is it PC or PCOffset?

[Vyacheslav Egorov (Google), 2012/05/17 21:16:27]

Done.

+  void SetPCAt(int idx, intptr_t pc);

[srdjan, 2012/05/17 17:22:08]

pc_offset?

[Vyacheslav Egorov (Google), 2012/05/17 21:16:27]

Done.

+
+  const String& CommentAt(int idx);

[srdjan, 2012/05/17 17:22:08]

const?

[Vyacheslav Egorov (Google), 2012/05/17 21:16:27]

Done.

[Vyacheslav Egorov (Google), 2012/05/17 21:16:27]

Done.

+  void SetCommentAt(int idx, const String& comment);
+
+ private:
+  explicit CodeComments(RawArray* comments);
+  CodeComments();

[srdjan, 2012/05/17 17:22:08]

Remove this constructor once it becomes ZoneObject

[Vyacheslav Egorov (Google), 2012/05/17 21:16:27]

Done.

+
+  const Array& comments_;
+
+  friend class Code;

[srdjan, 2012/05/17 17:22:08]

Remove this once moved inside class Code, I guess.

[Vyacheslav Egorov (Google), 2012/05/17 21:16:27]

Moving one class into another does not make these classes friends automatically.

+};
+
+
 class Code : public Object {
  public:
   RawInstructions* instructions() const { return raw_ptr()->instructions_; }
@@ -2180,6 +2208,9 @@ class Code : public Object {
   void set_stackmaps(const Array& maps) const;
   RawStackmap* GetStackmap(uword pc, Array* stackmaps, Stackmap* map) const;
 
+  CodeComments comments() const;

[srdjan, 2012/05/17 17:22:08]

const CodeComments&

[Vyacheslav Egorov (Google), 2012/05/17 21:16:27]

Done. However both Code::Comments::New and Code::comments started to look mighty
ugly in my opinion.

[Ivan Posva, 2012/05/22 22:40:02]

Maybe the real solution should be that the code comment handling does not have
anything to do with objects (except that the data is stored in an ObjectArray).
In reality code comments are something that is used to communicate between the
assembler and disassembler. How about moving it there?

+  void set_comments(const CodeComments& comments) const;
+
   RawLocalVarDescriptors* var_descriptors() const {
     return raw_ptr()->var_descriptors_;
   }