Mercurial > gnulib
view lib/unistr/u32-cmp.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 |
line wrap: on
line source
/* Compare pieces of UTF-32 strings. Copyright (C) 1999, 2002, 2006, 2009-2019 Free Software Foundation, Inc. Written by Bruno Haible <bruno@clisp.org>, 2002. This program is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser 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 Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this program. If not, see <https://www.gnu.org/licenses/>. */ #include <config.h> /* Specification. */ #include "unistr.h" int u32_cmp (const uint32_t *s1, const uint32_t *s2, size_t n) { for (; n > 0;) { uint32_t uc1 = *s1++; uint32_t uc2 = *s2++; if (uc1 == uc2) { n--; continue; } /* Note that uc1 and uc2 each have at most 31 bits. */ return (int)uc1 - (int)uc2; /* > 0 if uc1 > uc2, < 0 if uc1 < uc2. */ } return 0; }