view test/java/math/BigInteger/BitLengthOverflow.java @ 10542:0734e1584d9d

6910473: java.math.BigInteger.bitLength() may return negative "int" on large numbers 8021203: BigInteger.doubleValue/floatValue returns 0.0 instead of Infinity 8021204: Constructor BigInteger(String val, int radix) doesn't detect overflow 8022780: Incorrect BigInteger division because of MutableBigInteger.bitLength() overflow Summary: Prevent construction of overflowed BigIntegers. Reviewed-by: bpb, darcy, psandoz Contributed-by: Dmitry Nadezhin <dmitry.nadezhin@oracle.com>
author bpb
date Wed, 30 Oct 2013 17:45:12 -0700
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/*
 * 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.
 *
 * 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 6910473
 * @summary Test that bitLength() is not negative
 * @author Dmitry Nadezhin
 */
import java.math.BigInteger;

public class BitLengthOverflow {

    public static void main(String[] args) {

        try {
            BigInteger x = BigInteger.ONE.shiftLeft(Integer.MAX_VALUE); // x = pow(2,Integer.MAX_VALUE)
            if (x.bitLength() != (1L << 31))
                throw new RuntimeException("Incorrect bitLength() " + x.bitLength());
            System.out.println("Surprisingly passed with correct bitLength() " + x.bitLength());
        } catch (ArithmeticException e) {
            // expected
            System.out.println("Overflow is reported by ArithmeticException, as expected");
        } catch (OutOfMemoryError e) {
            // possible
            System.out.println("OutOfMemoryError");
        }
    }
}