Merge pull request #4469 from 9rnsr/fix12152

Issue 12152 - Cannot forward reference subclass member in superclass

src/class.c

@@ -548,15 +548,30 @@ void ClassDeclaration::semantic(Scope *sc)
         }
     }
 Lancestorsdone:
+    //printf("\tClassDeclaration::semantic(%s) doAncestorsSemantic = %d\n", toChars(), doAncestorsSemantic);
 
     if (!members)               // if opaque declaration
     {
         semanticRun = PASSsemanticdone;
         return;
     }
     if (!symtab)
+    {
         symtab = new DsymbolTable();
 
+        /* Bugzilla 12152: The semantic analysis of base classes should be finished
+         * before the members semantic analysis of this class, in order to determine
+         * vtbl in this class. However if a base class refers the member of this class,
+         * it can be resolved as a normal forward reference.
+         * Call addMember() to make this class members visible from the base classes.
+         */
+        for (size_t i = 0; i < members->dim; i++)
+        {
+            Dsymbol *s = (*members)[i];
+            s->addMember(sc, this, 1);
+        }
+    }
+
     for (size_t i = 0; i < baseclasses->dim; i++)
     {
         BaseClass *b = (*baseclasses)[i];
@@ -597,12 +612,6 @@ void ClassDeclaration::semantic(Scope *sc)
         }
         interfaceSemantic(sc);
 
-        for (size_t i = 0; i < members->dim; i++)
-        {
-            Dsymbol *s = (*members)[i];
-            s->addMember(sc, this, 1);
-        }
-
         /* If this is a nested class, add the hidden 'this'
          * member which is a pointer to the enclosing scope.
          */

test/compilable/testfwdref.d

@@ -0,0 +1,16 @@
+// PERMUTE_ARGS:
+
+/***************************************************/
+// 12152
+
+class A12152
+{
+    alias Y = B12152.X;
+}
+
+class B12152 : A12152
+{
+    alias int X;
+}
+
+static assert(is(A12152.Y == int));