Mercurial > gnulib
view tests/test-ffsl.c @ 40211:5f58d2ac35ea
unistr/u8-cmp: Fix undefined behaviour.
Reported by Jeffrey Walton <noloader@gmail.com>.
* lib/unistr/u8-cmp.c (u8_cmp): Don't invoke memcmp if n is zero.
author | Bruno Haible <bruno@clisp.org> |
---|---|
date | Fri, 08 Mar 2019 20:38:22 +0100 |
parents | b06060465f09 |
children |
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/* * Copyright (C) 2011-2019 Free Software Foundation, Inc. * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 3 of the License, or * (at your option) any later version. * * This program 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 for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <https://www.gnu.org/licenses/>. */ /* Written by Eric Blake. */ #include <config.h> #include <string.h> #include "signature.h" SIGNATURE_CHECK (ffsl, int, (long int)); #include <limits.h> #include "macros.h" #define NBITS (sizeof (long int) * CHAR_BIT) static int naive (long int i) { unsigned long int j; for (j = 0; j < NBITS; j++) if (i & (1UL << j)) return j + 1; return 0; } int main (int argc, char *argv[]) { long int x; int i; for (x = -128; x <= 128; x++) ASSERT (ffsl (x) == naive (x)); for (i = 0; i < NBITS; i++) { ASSERT (ffsl (1UL << i) == naive (1UL << i)); ASSERT (ffsl (1UL << i) == i + 1); ASSERT (ffsl (-1UL << i) == i + 1); } for (i = 0; i < NBITS - 1; i++) { ASSERT (ffsl (3UL << i) == i + 1); ASSERT (ffsl (-3UL << i) == i + 1); } for (i = 0; i < NBITS - 2; i++) { ASSERT (ffsl (5UL << i) == i + 1); ASSERT (ffsl (-5UL << i) == i + 1); ASSERT (ffsl (7UL << i) == i + 1); ASSERT (ffsl (-7UL << i) == i + 1); } return 0; }