1 /* $NetBSD: nan.c,v 1.2 2008/04/28 20:23:01 martin Exp $ */ 2 3 /*- 4 * Copyright (c) 2006 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Klaus Klein. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 #if defined(LIBM_SCCS) && !defined(lint) && !defined(NAN_FUNCTION) 34 __RCSID("$NetBSD: nan.c,v 1.2 2008/04/28 20:23:01 martin Exp $"); 35 #endif /* LIBM_SCCS and not lint */ 36 37 #include <assert.h> 38 #include <math.h> 39 #include <stddef.h> 40 #include <stdlib.h> 41 #include <string.h> 42 43 44 #ifndef NAN_FUNCTION 45 #define NAN_FUNCTION nan 46 #define NAN_TYPE double 47 #define NAN_STRTOD strtod 48 #endif 49 50 NAN_TYPE 51 NAN_FUNCTION(const char *tagp) 52 { 53 const char *nstr; 54 char *buf; 55 NAN_TYPE res; 56 57 _DIAGASSERT(tagp != NULL); 58 59 nstr = "NAN()"; 60 buf = NULL; 61 62 if (tagp[0] != '\0') { 63 size_t l; 64 65 l = strlen(tagp); 66 buf = malloc(5 + l + 1); 67 68 if (buf != NULL) { 69 /* Avoiding stdio in libm. */ 70 memcpy(buf, "NAN(", 4); 71 memcpy(buf + 4, tagp, l); 72 memcpy(buf + 4 + l, ")", 2); 73 nstr = buf; 74 } else { 75 /* Best effort: Fall back to "NAN()". */ 76 } 77 } 78 79 res = NAN_STRTOD(nstr, NULL); 80 81 if (buf != NULL) 82 free(buf); 83 84 return res; 85 } 86