VM: Fix bug in deferred loading.

runtime/vm/ast.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 RUNTIME_VM_AST_H_
 #define RUNTIME_VM_AST_H_
 
 #include "platform/assert.h"
 #include "vm/allocation.h"
 #include "vm/growable_array.h"
@@ skipping 546 matching lines @@
 };
 
 
 // Primary nodes hold identifiers or values (library, class or function)
 // resolved from an identifier. Primary nodes should not ever make it to the
 // code generation phase as they will be transformed into the correct call or
 // field access nodes.
 class PrimaryNode : public AstNode {
  public:
   PrimaryNode(TokenPosition token_pos, const Object& primary)
-      : AstNode(token_pos), primary_(primary), is_deferred_reference_(false) {
+      : AstNode(token_pos), primary_(primary), prefix_(NULL) {
     ASSERT(primary_.IsNotTemporaryScopedHandle());
   }
 
   const Object& primary() const { return primary_; }
 
-  void set_is_deferred(bool value) { is_deferred_reference_ = value; }
-  bool is_deferred_reference() const { return is_deferred_reference_; }
+  void set_prefix(const LibraryPrefix* prefix) { prefix_ = prefix; }

[rmacnak, 2017/01/05 22:50:11]

prefix -> deferred_prefix

ASSERT(prefix.is_deferred_load());

[Florian Schneider, 2017/01/06 02:12:12]

Done.

+  const LibraryPrefix* prefix() const { return prefix_; }
+  bool is_deferred_reference() const { return prefix_ != NULL; }
 
   bool IsSuper() const {
     return primary().IsString() && (primary().raw() == Symbols::Super().raw());
   }
 
   virtual void VisitChildren(AstNodeVisitor* visitor) const;
 
   DECLARE_COMMON_NODE_FUNCTIONS(PrimaryNode);
 
  private:
   const Object& primary_;
-  bool is_deferred_reference_;
+  const LibraryPrefix* prefix_;

[hausner, 2017/01/05 21:50:44]

We don't typically store pointers to handles in the ast.

[Florian Schneider, 2017/01/05 22:07:16]

I'd have to allocate an extra handle per PrimaryNode, right?
Also, we do store pointers to handles in a few places in
intermediate_language.h, so I don't see why not in the AST.

Would it be ok if I add an assertion that the pointer points to a ZoneHandle?
(i.e. not a scoped handle)

[hausner, 2017/01/05 22:39:40]

Fine with me. Yes, otherwise you'd have to allocate a handle. Or else you
introduce a null handle in the VM isolate, but that's overkill I think.

 
   DISALLOW_IMPLICIT_CONSTRUCTORS(PrimaryNode);
 };
 
 // In asynchronous code that gets suspended and resumed, return nodes
 // can be of different types:
 // * A regular return node that in the case of async functions
 //    gets replaced with appropriate completer calls. (kRegular)
 // * A continuation return that just returns from a function, without
 //   completing the Future. (kContinuation)
@@ skipping 1365 matching lines @@
   const intptr_t try_index_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(InlinedFinallyNode);
 };
 
 }  // namespace dart
 
 #undef DECLARE_COMMON_NODE_FUNCTIONS
 
 #endif  // RUNTIME_VM_AST_H_