1 /* $NetBSD: _strtol.h,v 1.1 2008/08/20 12:42:26 joerg Exp $ */ 2 3 /*- 4 * Copyright (c) 1990, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * Original version ID: 32 * NetBSD: src/lib/libc/locale/_wcstol.h,v 1.2 2003/08/07 16:43:03 agc Exp 33 */ 34 35 /* 36 * function template for strtol, strtoll and strtoimax. 37 * 38 * parameters: 39 * _FUNCNAME : function name 40 * __INT : return type 41 * __INT_MIN : lower limit of the return type 42 * __INT_MAX : upper limit of the return type 43 */ 44 45 __INT 46 _FUNCNAME(const char *nptr, char **endptr, int base) 47 { 48 const char *s; 49 __INT acc, cutoff; 50 unsigned char c; 51 int i, neg, any, cutlim; 52 53 _DIAGASSERT(nptr != NULL); 54 /* endptr may be NULL */ 55 56 /* check base value */ 57 if (base && (base < 2 || base > 36)) { 58 #if !defined(_KERNEL) && !defined(_STANDALONE) 59 errno = EINVAL; 60 return(0); 61 #else 62 panic("%s: invalid base %d", __func__, base); 63 #endif 64 } 65 66 /* 67 * Skip white space and pick up leading +/- sign if any. 68 * If base is 0, allow 0x for hex and 0 for octal, else 69 * assume decimal; if base is already 16, allow 0x. 70 */ 71 s = nptr; 72 do { 73 c = *s++; 74 } while (isspace(c)); 75 if (c == '-') { 76 neg = 1; 77 c = *s++; 78 } else { 79 neg = 0; 80 if (c == '+') 81 c = *s++; 82 } 83 if ((base == 0 || base == 16) && 84 c == '0' && (*s == 'x' || *s == 'X')) { 85 c = s[1]; 86 s += 2; 87 base = 16; 88 } 89 if (base == 0) 90 base = (c == '0' ? 8 : 10); 91 92 /* 93 * Compute the cutoff value between legal numbers and illegal 94 * numbers. That is the largest legal value, divided by the 95 * base. An input number that is greater than this value, if 96 * followed by a legal input character, is too big. One that 97 * is equal to this value may be valid or not; the limit 98 * between valid and invalid numbers is then based on the last 99 * digit. For instance, if the range for longs is 100 * [-2147483648..2147483647] and the input base is 10, 101 * cutoff will be set to 214748364 and cutlim to either 102 * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated 103 * a value > 214748364, or equal but the next digit is > 7 (or 8), 104 * the number is too big, and we will return a range error. 105 * 106 * Set any if any `digits' consumed; make it negative to indicate 107 * overflow. 108 */ 109 cutoff = (neg ? __INT_MIN : __INT_MAX); 110 cutlim = (int)(cutoff % base); 111 cutoff /= base; 112 if (neg) { 113 if (cutlim > 0) { 114 cutlim -= base; 115 cutoff += 1; 116 } 117 cutlim = -cutlim; 118 } 119 for (acc = 0, any = 0;; c = *s++) { 120 if (isdigit(c)) 121 i = c - '0'; 122 else if (isalpha(c)) 123 i = c - (isupper(c) ? 'A' - 10 : 'a' - 10); 124 else 125 break; 126 if (i >= base) 127 break; 128 if (any < 0) 129 continue; 130 if (neg) { 131 if (acc < cutoff || (acc == cutoff && i > cutlim)) { 132 acc = __INT_MIN; 133 #if !defined(_KERNEL) && !defined(_STANDALONE) 134 any = -1; 135 errno = ERANGE; 136 #else 137 any = 0; 138 break; 139 #endif 140 } else { 141 any = 1; 142 acc *= base; 143 acc -= i; 144 } 145 } else { 146 if (acc > cutoff || (acc == cutoff && i > cutlim)) { 147 acc = __INT_MAX; 148 #if !defined(_KERNEL) && !defined(_STANDALONE) 149 any = -1; 150 errno = ERANGE; 151 #else 152 any = 0; 153 break; 154 #endif 155 } else { 156 any = 1; 157 acc *= base; 158 acc += i; 159 } 160 } 161 } 162 if (endptr != NULL) 163 /* LINTED interface specification */ 164 *endptr = __UNCONST(any ? s - 1 : nptr); 165 return(acc); 166 } 167