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

runtime/vm/object.cc

Index: runtime/vm/object.cc
diff --git a/runtime/vm/object.cc b/runtime/vm/object.cc
index 86bd0b75b5a41a80af1696a8b22783424d70eb19..7e66611bf7135c9044838073fb20180f94cd15b2 100644
--- a/runtime/vm/object.cc
+++ b/runtime/vm/object.cc
@@ -6072,11 +6072,67 @@ const char* ExceptionHandlers::ToCString() const {
 }
 
 
+Code::Comments& Code::Comments::New(intptr_t count) {
+  Comments* comments;
+  if (count == 0) {
+    comments = new Comments(Array::Handle());

[srdjan, 2012/05/17 21:30:37]

The other option would be to use Array::Empty() in this casem so that you do not
need to check fort NULL-ness. Your choice.

+  } else {
+    comments = new Comments(Array::Handle(
+        Array::New(count * kNumberOfEntries)));
+  }
+  return *comments;
+}
+
+
+intptr_t Code::Comments::Length() const {
+  return comments_.IsNull() ? 0 : (comments_.Length() / kNumberOfEntries);
+}
+
+
+intptr_t Code::Comments::PCOffsetAt(intptr_t idx) const {
+  return Smi::CheckedHandle(
+      comments_.At(idx * kNumberOfEntries + kPCOffsetEntry)).Value();
+}
+
+
+void Code::Comments::SetPCOffsetAt(intptr_t idx, intptr_t pc)  {
+  comments_.SetAt(idx * kNumberOfEntries + kPCOffsetEntry,
+                  Smi::Handle(Smi::New(pc)));
+}
+
+
+const String& Code::Comments::CommentAt(intptr_t idx) const {
+  return String::CheckedHandle(
+      comments_.At(idx * kNumberOfEntries + kCommentEntry));
+}
+
+
+void Code::Comments::SetCommentAt(intptr_t idx, const String& comment) {
+  comments_.SetAt(idx * kNumberOfEntries + kCommentEntry, comment);
+}
+
+
+Code::Comments::Comments(const Array& comments)
+    : comments_(comments) {
+}
+
+
 void Code::set_stackmaps(const Array& maps) const {
   StorePointer(&raw_ptr()->stackmaps_, maps.raw());
 }
 
 
+const Code::Comments& Code::comments() const  {
+  Comments* comments = new Code::Comments(Array::Handle(raw_ptr()->comments_));
+  return *comments;
+}
+
+
+void Code::set_comments(const Code::Comments& comments) const {
+  StorePointer(&raw_ptr()->comments_, comments.comments_.raw());
+}
+
+
 RawCode* Code::New(int pointer_offsets_length) {
   const Class& cls = Class::Handle(Object::code_class());
   Code& result = Code::Handle();