1 /* $FreeBSD: head/lib/libc/iconv/_strtol.h 219019 2011-02-25 00:04:39Z gabor $ */ 2 /* $NetBSD: _strtol.h,v 1.2 2009/05/20 22:03:29 christos Exp $ */ 3 4 /*- 5 * Copyright (c) 1990, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * Original version ID: 33 * NetBSD: src/lib/libc/locale/_wcstol.h,v 1.2 2003/08/07 16:43:03 agc Exp 34 */ 35 36 /* 37 * function template for strtol, strtoll and strtoimax. 38 * 39 * parameters: 40 * _FUNCNAME : function name 41 * __INT : return type 42 * INT_MIN : lower limit of the return type 43 * INT_MAX : upper limit of the return type 44 */ 45 46 __INT 47 _FUNCNAME(const char *nptr, char **endptr, int base) 48 { 49 const char *s; 50 __INT acc, cutoff; 51 unsigned char c; 52 int any, cutlim, i, neg; 53 54 /* check base value */ 55 if (base && (base < 2 || base > 36)) { 56 #if !defined(_KERNEL) && !defined(_STANDALONE) 57 errno = EINVAL; 58 if (endptr != NULL) 59 /* LINTED interface specification */ 60 *endptr = __DECONST(void *, nptr); 61 return (0); 62 #else 63 panic("%s: invalid base %d", __func__, base); 64 #endif 65 } 66 67 /* 68 * Skip white space and pick up leading +/- sign if any. 69 * If base is 0, allow 0x for hex and 0 for octal, else 70 * assume decimal; if base is already 16, allow 0x. 71 */ 72 s = nptr; 73 do { 74 c = *s++; 75 } while (isspace(c)); 76 if (c == '-') { 77 neg = 1; 78 c = *s++; 79 } else { 80 neg = 0; 81 if (c == '+') 82 c = *s++; 83 } 84 if ((base == 0 || base == 16) && 85 c == '0' && (*s == 'x' || *s == 'X')) { 86 c = s[1]; 87 s += 2; 88 base = 16; 89 } 90 if (base == 0) 91 base = (c == '0' ? 8 : 10); 92 93 /* 94 * Compute the cutoff value between legal numbers and illegal 95 * numbers. That is the largest legal value, divided by the 96 * base. An input number that is greater than this value, if 97 * followed by a legal input character, is too big. One that 98 * is equal to this value may be valid or not; the limit 99 * between valid and invalid numbers is then based on the last 100 * digit. For instance, if the range for longs is 101 * [-2147483648..2147483647] and the input base is 10, 102 * cutoff will be set to 214748364 and cutlim to either 103 * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated 104 * a value > 214748364, or equal but the next digit is > 7 (or 8), 105 * the number is too big, and we will return a range error. 106 * 107 * Set any if any `digits' consumed; make it negative to indicate 108 * overflow. 109 */ 110 cutoff = (neg ? INT_MIN : INT_MAX); 111 cutlim = (int)(cutoff % base); 112 cutoff /= base; 113 if (neg) { 114 if (cutlim > 0) { 115 cutlim -= base; 116 cutoff += 1; 117 } 118 cutlim = -cutlim; 119 } 120 for (acc = 0, any = 0;; c = *s++) { 121 if (isdigit(c)) 122 i = c - '0'; 123 else if (isalpha(c)) 124 i = c - (isupper(c) ? 'A' - 10 : 'a' - 10); 125 else 126 break; 127 if (i >= base) 128 break; 129 if (any < 0) 130 continue; 131 if (neg) { 132 if (acc < cutoff || (acc == cutoff && i > cutlim)) { 133 acc = INT_MIN; 134 #if !defined(_KERNEL) && !defined(_STANDALONE) 135 any = -1; 136 errno = ERANGE; 137 #else 138 any = 0; 139 break; 140 #endif 141 } else { 142 any = 1; 143 acc *= base; 144 acc -= i; 145 } 146 } else { 147 if (acc > cutoff || (acc == cutoff && i > cutlim)) { 148 acc = INT_MAX; 149 #if !defined(_KERNEL) && !defined(_STANDALONE) 150 any = -1; 151 errno = ERANGE; 152 #else 153 any = 0; 154 break; 155 #endif 156 } else { 157 any = 1; 158 acc *= base; 159 acc += i; 160 } 161 } 162 } 163 if (endptr != NULL) 164 /* LINTED interface specification */ 165 *endptr = __DECONST(void *, any ? s - 1 : nptr); 166 return(acc); 167 } 168