Fix lazy initialization of static fields (issue 2472).

runtime/vm/ast.cc

 // Copyright (c) 2011, 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.
 
 #include "vm/ast.h"
 #include "vm/compiler.h"
 #include "vm/dart_entry.h"
 #include "vm/isolate.h"
 #include "vm/object_store.h"
 
@@ skipping 388 matching lines @@
                                          bool is_prefix) {
   return new IncrOpIndexedNode(token_index,
                                kind,
                                is_prefix,
                                array(),
                                index_expr());
 }
 
 
 AstNode* StaticGetterNode::MakeAssignmentNode(AstNode* rhs) {
-  return new StaticSetterNode(token_index(), cls(), field_name(), rhs);
+  // If no setter exist, set the field directly.
+  const String& setter_name = String::Handle(Field::SetterName(field_name()));
+  const Function& function =
+      Function::ZoneHandle(cls().LookupStaticFunction(setter_name));
+  if (function.IsNull()) {
+    const Field& field = Field::ZoneHandle(
+        cls().LookupStaticField(field_name()));
+    ASSERT(!field.IsNull());

[srdjan, 2012/04/11 19:52:51]

Please add a comment why the field must exist.

[regis, 2012/04/11 21:11:24]

Done. I added a comment and debugging code verifying that we are indeed dealing
with lazy initialization.

    // Access to a lazily initialized static field that has not yet been
    // initialized is compiled to a static implicit const getter.
    // A setter may not exist for such a field.

+    return new StoreStaticFieldNode(token_index(), field, rhs);
+  } else {
+    return new StaticSetterNode(token_index(), cls(), field_name(), rhs);
+  }
 }
 
 
 AstNode* StaticGetterNode::MakeIncrOpNode(intptr_t token_index,
                                           Token::Kind kind,
                                           bool is_prefix) {
   UNIMPLEMENTED();
   return NULL;
 }
 
@@ skipping 17 matching lines @@
     // the Error object directly to the parser.  This will involve
     // replumbing all of the EvalConstExpr methods.
     return NULL;
   }
   Instance& field_value = Instance::ZoneHandle();
   field_value ^= result.raw();
   return &field_value;
 }
 
 }  // namespace dart