1 /* $FreeBSD$ */ 2 /* $NetBSD: _strtol.h,v 1.2 2009/05/20 22:03:29 christos Exp $ */ 3 4 /*- 5 * SPDX-License-Identifier: BSD-3-Clause 6 * 7 * Copyright (c) 1990, 1993 8 * The Regents of the University of California. All rights reserved. 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 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * Original version ID: 35 * NetBSD: src/lib/libc/locale/_wcstol.h,v 1.2 2003/08/07 16:43:03 agc Exp 36 */ 37 38 /* 39 * function template for strtol, strtoll and strtoimax. 40 * 41 * parameters: 42 * _FUNCNAME : function name 43 * __INT : return type 44 * __INT_MIN : lower limit of the return type 45 * __INT_MAX : upper limit of the return type 46 */ 47 48 __INT 49 _FUNCNAME(const char *nptr, char **endptr, int base) 50 { 51 const char *s; 52 __INT acc, cutoff; 53 unsigned char c; 54 int any, cutlim, i, neg; 55 56 /* check base value */ 57 if (base && (base < 2 || base > 36)) { 58 #if !defined(_KERNEL) && !defined(_STANDALONE) 59 errno = EINVAL; 60 if (endptr != NULL) 61 /* LINTED interface specification */ 62 *endptr = __DECONST(void *, nptr); 63 return (0); 64 #else 65 panic("%s: invalid base %d", __func__, base); 66 #endif 67 } 68 69 /* 70 * Skip white space and pick up leading +/- sign if any. 71 * If base is 0, allow 0x for hex and 0 for octal, else 72 * assume decimal; if base is already 16, allow 0x. 73 */ 74 s = nptr; 75 do { 76 c = *s++; 77 } while (isspace(c)); 78 if (c == '-') { 79 neg = 1; 80 c = *s++; 81 } else { 82 neg = 0; 83 if (c == '+') 84 c = *s++; 85 } 86 if ((base == 0 || base == 16) && 87 c == '0' && (*s == 'x' || *s == 'X')) { 88 c = s[1]; 89 s += 2; 90 base = 16; 91 } 92 if (base == 0) 93 base = (c == '0' ? 8 : 10); 94 95 /* 96 * Compute the cutoff value between legal numbers and illegal 97 * numbers. That is the largest legal value, divided by the 98 * base. An input number that is greater than this value, if 99 * followed by a legal input character, is too big. One that 100 * is equal to this value may be valid or not; the limit 101 * between valid and invalid numbers is then based on the last 102 * digit. For instance, if the range for longs is 103 * [-2147483648..2147483647] and the input base is 10, 104 * cutoff will be set to 214748364 and cutlim to either 105 * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated 106 * a value > 214748364, or equal but the next digit is > 7 (or 8), 107 * the number is too big, and we will return a range error. 108 * 109 * Set any if any `digits' consumed; make it negative to indicate 110 * overflow. 111 */ 112 cutoff = (neg ? __INT_MIN : __INT_MAX); 113 cutlim = (int)(cutoff % base); 114 cutoff /= base; 115 if (neg) { 116 if (cutlim > 0) { 117 cutlim -= base; 118 cutoff += 1; 119 } 120 cutlim = -cutlim; 121 } 122 for (acc = 0, any = 0;; c = *s++) { 123 if (isdigit(c)) 124 i = c - '0'; 125 else if (isalpha(c)) 126 i = c - (isupper(c) ? 'A' - 10 : 'a' - 10); 127 else 128 break; 129 if (i >= base) 130 break; 131 if (any < 0) 132 continue; 133 if (neg) { 134 if (acc < cutoff || (acc == cutoff && i > cutlim)) { 135 acc = __INT_MIN; 136 #if !defined(_KERNEL) && !defined(_STANDALONE) 137 any = -1; 138 errno = ERANGE; 139 #else 140 any = 0; 141 break; 142 #endif 143 } else { 144 any = 1; 145 acc *= base; 146 acc -= i; 147 } 148 } else { 149 if (acc > cutoff || (acc == cutoff && i > cutlim)) { 150 acc = __INT_MAX; 151 #if !defined(_KERNEL) && !defined(_STANDALONE) 152 any = -1; 153 errno = ERANGE; 154 #else 155 any = 0; 156 break; 157 #endif 158 } else { 159 any = 1; 160 acc *= base; 161 acc += i; 162 } 163 } 164 } 165 if (endptr != NULL) 166 /* LINTED interface specification */ 167 *endptr = __DECONST(void *, any ? s - 1 : nptr); 168 return(acc); 169 } 170