NetBSD/lib/libm/gen/nan.c

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/* $NetBSD: nan.c,v 1.2 2008/04/28 20:23:01 martin Exp $ */
/*-
* Copyright (c) 2006 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Klaus Klein.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#if defined(LIBM_SCCS) && !defined(lint) && !defined(NAN_FUNCTION)
__RCSID("$NetBSD: nan.c,v 1.2 2008/04/28 20:23:01 martin Exp $");
#endif /* LIBM_SCCS and not lint */
#include <assert.h>
#include <math.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#ifndef NAN_FUNCTION
#define NAN_FUNCTION nan
#define NAN_TYPE double
#define NAN_STRTOD strtod
#endif
NAN_TYPE
NAN_FUNCTION(const char *tagp)
{
const char *nstr;
char *buf;
NAN_TYPE res;
_DIAGASSERT(tagp != NULL);
nstr = "NAN()";
buf = NULL;
if (tagp[0] != '\0') {
size_t l;
l = strlen(tagp);
buf = malloc(5 + l + 1);
if (buf != NULL) {
/* Avoiding stdio in libm. */
memcpy(buf, "NAN(", 4);
memcpy(buf + 4, tagp, l);
memcpy(buf + 4 + l, ")", 2);
nstr = buf;
} else {
/* Best effort: Fall back to "NAN()". */
}
}
res = NAN_STRTOD(nstr, NULL);
if (buf != NULL)
free(buf);
return res;
}