NullCheckTest.java

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/**
 * @test
 * @bug 6478991
 * @summary C1 NullCheckEliminator yields incorrect exceptions
 *
 * @run main/othervm -XX:CompileOnly=NullCheckTest.test,NullCheckTest.inlined  -Xcomp NullCheckTest
 */

public class NullCheckTest {
        static class A {
                int f;

                public final void inlined(A a) {
                        // This cast is intended to fail.
                        B b = ((B) a);
                }
        }

        static class B extends A {
        }


        private static void test(A a1, A a2) {
                // Inlined call must do a null check on a1.
                // However, the exlipcit NullCheck instruction is eliminated and
                // the null check is folded into the field load below, so the
                // exception in the inlined method is thrown before the null check
                // and the NullPointerException is not thrown.
                a1.inlined(a2);

                int x = a1.f;
        }

        public static void main(String[] args) {
                // load classes
                new B();
                try {
                        test(null, new A());

                        throw new InternalError("FAILURE: no exception");
                } catch (NullPointerException ex) {
                        System.out.println("CORRECT: NullPointerException");
                } catch (ClassCastException ex) {
                        System.out.println("FAILURE: ClassCastException");
                        throw ex;
                }
        }
}