8023112: javac should not use lazy constant evaluation approach for method references

Reviewed-by: jjg, mcimadamore

langtools/src/share/classes/com/sun/tools/javac/comp/Attr.java

@@ -1063,9 +1063,7 @@ public class Attr extends JCTree.Visitor {
 
             if (tree.init != null) {
                 if ((v.flags_field & FINAL) != 0 &&
-                        !tree.init.hasTag(NEWCLASS) &&
+                    memberEnter.needsLazyConstValue(tree.init)) {
-                        !tree.init.hasTag(LAMBDA) &&
-                        !tree.init.hasTag(REFERENCE)) {
                     // In this case, `v' is final.  Ensure that it's initializer is
                     // evaluated.
                     v.getConstValue(); // ensure initializer is evaluated

langtools/src/share/classes/com/sun/tools/javac/comp/MemberEnter.java

@@ -677,8 +677,7 @@ public class MemberEnter extends JCTree.Visitor implements Completer {
         if (tree.init != null) {
             v.flags_field |= HASINIT;
             if ((v.flags_field & FINAL) != 0 &&
-                    !tree.init.hasTag(NEWCLASS) &&
+                needsLazyConstValue(tree.init)) {
-                    !tree.init.hasTag(LAMBDA)) {
                 Env<AttrContext> initEnv = getInitEnv(tree, env);
                 initEnv.info.enclVar = v;
                 v.setLazyConstValue(initEnv(tree, initEnv), attr, tree.init);
@@ -700,6 +699,59 @@ public class MemberEnter extends JCTree.Visitor implements Completer {
         }
     }
 
+    public boolean needsLazyConstValue(JCTree tree) {
+        InitTreeVisitor initTreeVisitor = new InitTreeVisitor();
+        tree.accept(initTreeVisitor);
+        return initTreeVisitor.result;
+    }
+
+    /** Visitor class for expressions which might be constant expressions.
+     */
+    static class InitTreeVisitor extends JCTree.Visitor {
+
+        private boolean result = true;
+
+        @Override
+        public void visitTree(JCTree tree) {}
+
+        @Override
+        public void visitNewClass(JCNewClass that) {
+            result = false;
+        }
+
+        @Override
+        public void visitLambda(JCLambda that) {
+            result = false;
+        }
+
+        @Override
+        public void visitReference(JCMemberReference that) {
+            result = false;
+        }
+
+        @Override
+        public void visitSelect(JCFieldAccess tree) {
+            tree.selected.accept(this);
+        }
+
+        @Override
+        public void visitConditional(JCConditional tree) {
+            tree.cond.accept(this);
+            tree.truepart.accept(this);
+            tree.falsepart.accept(this);
+        }
+
+        @Override
+        public void visitParens(JCParens tree) {
+            tree.expr.accept(this);
+        }
+
+        @Override
+        public void visitTypeCast(JCTypeCast tree) {
+            tree.expr.accept(this);
+        }
+    }
+
     /** Create a fresh environment for a variable's initializer.
      *  If the variable is a field, the owner of the environment's scope
      *  is be the variable itself, otherwise the owner is the method

langtools/test/tools/javac/T8023112/SkipLazyConstantCreationForMethodRefTest.java

@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8023112
+ * @summary Mixing up the method type argument with the class type for method
+ *          reference ClassType<Q>::<T>new
+ * @compile SkipLazyConstantCreationForMethodRefTest.java
+ */
+
+public class SkipLazyConstantCreationForMethodRefTest<T> {
+    SkipLazyConstantCreationForMethodRefTest(int a, boolean b) {}
+    SkipLazyConstantCreationForMethodRefTest() {}
+}
+
+class SubClass<T> extends SkipLazyConstantCreationForMethodRefTest {
+    SubClass(int a, boolean b) {}
+}
+
+interface SAM {
+    SubClass<SkipLazyConstantCreationForMethodRefTest> m(int a, boolean b);
+}
+
+interface Tester1 {
+    SAM s11 = SubClass<SkipLazyConstantCreationForMethodRefTest>::<Object>new;
+    SAM s12 = (SubClass<SkipLazyConstantCreationForMethodRefTest>::<Object>new);
+    SAM s13 = (SAM)SubClass<SkipLazyConstantCreationForMethodRefTest>::<Object>new;
+    SAM s14 = true ? s11 : s12;
+    SAM s15 = true ? s11 : (SAM)SubClass<SkipLazyConstantCreationForMethodRefTest>::<Object>new;
+    SAM s16 = true ? (SAM)SubClass<SkipLazyConstantCreationForMethodRefTest>::<Object>new : s12;
+}
+
+interface Tester2 {
+    SAM s21 = Tester1.s11;
+}