Toward precompiled snapshots.

runtime/vm/raw_object.h

Index: runtime/vm/raw_object.h
diff --git a/runtime/vm/raw_object.h b/runtime/vm/raw_object.h
index fe8425911540386ea12e78ffe4233d2b07b323bc..c6f39caac7f4aa4388083b9b2a80f3b09e7011c1 100644
--- a/runtime/vm/raw_object.h
+++ b/runtime/vm/raw_object.h
@@ -583,6 +583,7 @@ class RawObject {
   friend class ScavengerVisitor;
   friend class SizeExcludingClassVisitor;  // GetClassId
   friend class RetainingPathVisitor;  // GetClassId
+  friend class InstructionsReader;  // tags_ check
   friend class SnapshotReader;
   friend class SnapshotWriter;
   friend class String;
@@ -1002,7 +1003,7 @@ class RawCode : public RawObject {
   // Else, return_address_info_ is null.
   RawObject* return_address_metadata_;
   RawObject** to() {
-    return reinterpret_cast<RawObject**>(&ptr()->comments_);
+    return reinterpret_cast<RawObject**>(&ptr()->return_address_metadata_);
   }
   uword entry_point_;
 
@@ -1048,6 +1049,7 @@ class RawObjectPool : public RawObject {
   Entry* first_entry() { return &ptr()->data()[0]; }
 
   friend class Object;
+  friend class SnapshotReader;
 };
 
 
@@ -1078,6 +1080,7 @@ class RawInstructions : public RawObject {
   friend class StackFrame;
   friend class MarkingVisitor;
   friend class Function;
+  friend class InstructionsReader;
 };
 
 
@@ -1135,6 +1138,7 @@ class RawPcDescriptors : public RawObject {
   const uint8_t* data() const { OPEN_ARRAY_START(uint8_t, intptr_t); }
 
   friend class Object;
+  friend class SnapshotReader;
 };
 
 
@@ -1142,9 +1146,8 @@ class RawPcDescriptors : public RawObject {
 // PC. The stack map representation consists of a bit map which marks each
 // live object index starting from the base of the frame.
 //
-// The Stackmap also consists of a link to the code object corresponding to
-// the frame which the stack map is describing.  The bit map representation
-// is optimized for dense and small bit maps, without any upper bound.
+// The bit map representation is optimized for dense and small bit maps, without
+// any upper bound.
 class RawStackmap : public RawObject {
   RAW_HEAP_OBJECT_IMPLEMENTATION(Stackmap);
 
@@ -1162,6 +1165,8 @@ class RawStackmap : public RawObject {
   // Variable length data follows here (bitmap of the stack layout).
   uint8_t* data() { OPEN_ARRAY_START(uint8_t, uint8_t); }
   const uint8_t* data() const { OPEN_ARRAY_START(uint8_t, uint8_t); }
+
+  friend class SnapshotReader;
 };
 
 
@@ -1236,6 +1241,7 @@ class RawLocalVarDescriptors : public RawObject {
   }
 
   friend class Object;
+  friend class SnapshotReader;
 };
 
 
@@ -1265,6 +1271,7 @@ class RawExceptionHandlers : public RawObject {
   HandlerInfo* data() { OPEN_ARRAY_START(HandlerInfo, intptr_t); }
 
   friend class Object;
+  friend class SnapshotReader;
 };