1 /*
  2  * Copyright (c) 2024, Oracle and/or its affiliates. All rights reserved.
  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  4  *
  5  * This code is free software; you can redistribute it and/or modify it
  6  * under the terms of the GNU General Public License version 2 only, as
  7  * published by the Free Software Foundation.
  8  *
  9  * This code is distributed in the hope that it will be useful, but WITHOUT
 10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 12  * version 2 for more details (a copy is included in the LICENSE file that
 13  * accompanied this code).
 14  *
 15  * You should have received a copy of the GNU General Public License version
 16  * 2 along with this work; if not, write to the Free Software Foundation,
 17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 18  *
 19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 20  * or visit www.oracle.com if you need additional information or have any
 21  * questions.
 22  */
 23 
 24 /*
 25  * @test
 26  * @modules jdk.incubator.code
 27  * @run junit TestUninitializedVariable
 28  */
 29 
 30 import jdk.incubator.code.CodeReflection;
 31 import jdk.incubator.code.Op;
 32 import jdk.incubator.code.OpTransformer;
 33 import jdk.incubator.code.analysis.SSA;
 34 import jdk.incubator.code.dialect.core.CoreOp;
 35 import jdk.incubator.code.interpreter.Interpreter;
 36 import org.junit.jupiter.api.Assertions;
 37 import org.junit.jupiter.params.ParameterizedTest;
 38 import org.junit.jupiter.params.provider.MethodSource;
 39 
 40 import java.lang.invoke.MethodHandles;
 41 import java.lang.reflect.Method;
 42 import java.util.Optional;
 43 import java.util.concurrent.atomic.AtomicBoolean;
 44 import java.util.stream.Stream;
 45 
 46 public class TestUninitializedVariable {
 47 
 48     @CodeReflection
 49     static int simple(int i) {
 50         int x;
 51         x = i; // drop store
 52         return x;
 53     }
 54 
 55     @CodeReflection
 56     static int controlFlow(int i) {
 57         int x;
 58         if (i > 0) {
 59             x = i;  // drop store
 60         } else {
 61             x = -i;
 62         }
 63         return x;
 64     }
 65 
 66     static Stream<String> methods() {
 67         return Stream.of("simple", "controlFlow");
 68     }
 69 
 70     @ParameterizedTest
 71     @MethodSource("methods")
 72     public void testInterpret(String method) {
 73         CoreOp.FuncOp f = removeFirstStore(getFuncOp(method).transform(OpTransformer.LOWERING_TRANSFORMER));
 74         System.out.println(f.toText());
 75 
 76         Assertions.assertThrows(Interpreter.InterpreterException.class, () -> Interpreter.invoke(MethodHandles.lookup(), f, 1));
 77     }
 78 
 79     @ParameterizedTest
 80     @MethodSource("methods")
 81     public void testSSA(String method) {
 82         CoreOp.FuncOp f = removeFirstStore(getFuncOp(method).transform(OpTransformer.LOWERING_TRANSFORMER));
 83         System.out.println(f.toText());
 84 
 85         Assertions.assertThrows(IllegalStateException.class, () -> SSA.transform(f));
 86     }
 87 
 88     static CoreOp.FuncOp removeFirstStore(CoreOp.FuncOp f) {
 89         AtomicBoolean b = new AtomicBoolean();
 90         return f.transform((block, op) -> {
 91             if (op instanceof CoreOp.VarAccessOp.VarStoreOp vop && !b.getAndSet(true)) {
 92                 // Drop first encountered var store
 93             } else {
 94                 block.op(op);
 95             }
 96             return block;
 97         });
 98     }
 99 
100     static CoreOp.FuncOp getFuncOp(String name) {
101         Optional<Method> om = Stream.of(TestUninitializedVariable.class.getDeclaredMethods())
102                 .filter(m -> m.getName().equals(name))
103                 .findFirst();
104 
105         Method m = om.get();
106         return Op.ofMethod(m).get();
107     }
108 }