8015499: javac, Gen is generating extra checkcast instructions in some corner cases
authorpgovereau
Wed, 09 Apr 2014 17:41:27 +0100
changeset 23812 a53aa842f5cf
parent 23811 4bbbcaad653f
child 23813 1a2765f25d5f
8015499: javac, Gen is generating extra checkcast instructions in some corner cases Reviewed-by: vromero, jjg
langtools/src/share/classes/com/sun/tools/javac/comp/TransTypes.java
langtools/test/tools/javac/T7053059/DoubleCastTest.java
--- a/langtools/src/share/classes/com/sun/tools/javac/comp/TransTypes.java	Tue Apr 08 23:33:50 2014 +0200
+++ b/langtools/src/share/classes/com/sun/tools/javac/comp/TransTypes.java	Wed Apr 09 17:41:27 2014 +0100
@@ -748,7 +748,7 @@
         tree.clazz = translate(tree.clazz, null);
         Type originalTarget = tree.type;
         tree.type = erasure(tree.type);
-        tree.expr = translate(tree.expr, tree.type);
+        tree.expr = translate(tree.expr, erasure(tree.expr.type));
         if (originalTarget.isCompound()) {
             Type.IntersectionClassType ict = (Type.IntersectionClassType)originalTarget;
             for (Type c : ict.getExplicitComponents()) {
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/tools/javac/T7053059/DoubleCastTest.java	Wed Apr 09 17:41:27 2014 +0100
@@ -0,0 +1,76 @@
+/*
+ * Copyright (c) 2014, 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.
+ *
+ * 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 8015499
+ * @summary javac, Gen is generating extra checkcast instructions in some corner cases
+ * @run main DoubleCastTest
+ */
+
+import java.util.List;
+import java.util.ArrayList;
+import com.sun.tools.classfile.*;
+import com.sun.tools.javac.util.Assert;
+
+public class DoubleCastTest {
+    class C {
+        Object x;
+        Object m() { return null; }
+        void m1(byte[] b) {}
+        void m2() {
+            Object o;
+            Object[] os = null;
+            m1((byte[])(o = null));
+            m1((byte[])o);
+            m1((byte[])(o == null ? o : o));
+            m1((byte[])m());
+            m1((byte[])os[0]);
+            m1((byte[])this.x);
+        }
+    }
+
+    public static void main(String... cmdline) throws Exception {
+
+        ClassFile cls = ClassFile.read(DoubleCastTest.class.getResourceAsStream("DoubleCastTest$C.class"));
+        for (Method m: cls.methods)
+            check(m);
+    }
+
+    static void check(Method m) throws Exception {
+        boolean last_is_cast = false;
+        int last_ref = 0;
+        Code_attribute ea = (Code_attribute)m.attributes.get(Attribute.Code);
+        for (Instruction i : ea.getInstructions()) {
+            if (i.getOpcode() == Opcode.CHECKCAST) {
+                Assert.check
+                    (!(last_is_cast && last_ref == i.getUnsignedShort(1)),
+                     "Double cast found - Test failed");
+                last_is_cast = true;
+                last_ref = i.getUnsignedShort(1);
+            } else {
+                last_is_cast = false;
+            }
+        }
+    }
+}