1 /* $DragonFly: src/lib/libc/stdlib/_strtol.h,v 1.1 2005/03/17 15:09:01 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 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 errno = EINVAL; 59 return(0); 60 } 61 62 /* 63 * Skip white space and pick up leading +/- sign if any. 64 * If base is 0, allow 0x for hex and 0 for octal, else 65 * assume decimal; if base is already 16, allow 0x. 66 */ 67 s = nptr; 68 do { 69 c = *s++; 70 } while (isspace(c)); 71 if (c == '-') { 72 neg = 1; 73 c = *s++; 74 } else { 75 neg = 0; 76 if (c == '+') 77 c = *s++; 78 } 79 if ((base == 0 || base == 16) && 80 c == '0' && (*s == 'x' || *s == 'X')) { 81 c = s[1]; 82 s += 2; 83 base = 16; 84 } 85 if (base == 0) 86 base = c == '0' ? 8 : 10; 87 88 /* 89 * Compute the cutoff value between legal numbers and illegal 90 * numbers. That is the largest legal value, divided by the 91 * base. An input number that is greater than this value, if 92 * followed by a legal input character, is too big. One that 93 * is equal to this value may be valid or not; the limit 94 * between valid and invalid numbers is then based on the last 95 * digit. For instance, if the range for longs is 96 * [-2147483648..2147483647] and the input base is 10, 97 * cutoff will be set to 214748364 and cutlim to either 98 * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated 99 * a value > 214748364, or equal but the next digit is > 7 (or 8), 100 * the number is too big, and we will return a range error. 101 * 102 * Set any if any `digits' consumed; make it negative to indicate 103 * overflow. 104 */ 105 cutoff = neg ? __INT_MIN : __INT_MAX; 106 cutlim = (int)(cutoff % base); 107 cutoff /= base; 108 if (neg) { 109 if (cutlim > 0) { 110 cutlim -= base; 111 cutoff += 1; 112 } 113 cutlim = -cutlim; 114 } 115 for (acc = 0, any = 0;; c = *s++) { 116 if (!isascii(c)) 117 break; 118 if (isdigit(c)) 119 i = c - '0'; 120 else if (isalpha(c)) 121 i = c - (isupper(c) ? 'A' - 10 : 'a' - 10); 122 else 123 break; 124 if (i >= base) 125 break; 126 if (any < 0) 127 continue; 128 if (neg) { 129 if (acc < cutoff || (acc == cutoff && i > cutlim)) { 130 any = -1; 131 acc = __INT_MIN; 132 errno = ERANGE; 133 } else { 134 any = 1; 135 acc *= base; 136 acc -= i; 137 } 138 } else { 139 if (acc > cutoff || (acc == cutoff && i > cutlim)) { 140 any = -1; 141 acc = __INT_MAX; 142 errno = ERANGE; 143 } else { 144 any = 1; 145 acc *= base; 146 acc += i; 147 } 148 } 149 } 150 if (endptr != 0) 151 /* LINTED interface specification */ 152 *endptr = __DECONST(char *, (any ? s - 1 : nptr)); 153 return(acc); 154 } 155