Annotation of XNU/bsd/libkern/strtol.c, revision 1.1

1.1     ! root        1: /*
        !             2:  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
        !             3:  *
        !             4:  * @APPLE_LICENSE_HEADER_START@
        !             5:  * 
        !             6:  * The contents of this file constitute Original Code as defined in and
        !             7:  * are subject to the Apple Public Source License Version 1.1 (the
        !             8:  * "License").  You may not use this file except in compliance with the
        !             9:  * License.  Please obtain a copy of the License at
        !            10:  * http://www.apple.com/publicsource and read it before using this file.
        !            11:  * 
        !            12:  * This Original Code and all software distributed under the License are
        !            13:  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
        !            14:  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
        !            15:  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
        !            16:  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
        !            17:  * License for the specific language governing rights and limitations
        !            18:  * under the License.
        !            19:  * 
        !            20:  * @APPLE_LICENSE_HEADER_END@
        !            21:  */
        !            22: /*      Copyright (c) 1995 NeXT Computer, Inc.  All rights reserved.
        !            23:  *
        !            24:  * strol.c - The functions strtol() & strtoul() are exported as public API
        !            25:  *           via the header file ~driverkit/generalFuncs.h
        !            26:  *
        !            27:  * HISTORY
        !            28:  * 25-Oct-1995    Dean Reece at NeXT
        !            29:  *      Created based on BSD4.4's strtol.c & strtoul.c.
        !            30:  *      Removed dependency on _ctype_ by static versions of isupper()...
        !            31:  *      Added support for "0b101..." binary constants.
        !            32:  *      Commented out references to errno.
        !            33:  */
        !            34: 
        !            35: /*-
        !            36:  * Copyright (c) 1990, 1993
        !            37:  *     The Regents of the University of California.  All rights reserved.
        !            38:  *
        !            39:  * Redistribution and use in source and binary forms, with or without
        !            40:  * modification, are permitted provided that the following conditions
        !            41:  * are met:
        !            42:  * 1. Redistributions of source code must retain the above copyright
        !            43:  *    notice, this list of conditions and the following disclaimer.
        !            44:  * 2. Redistributions in binary form must reproduce the above copyright
        !            45:  *    notice, this list of conditions and the following disclaimer in the
        !            46:  *    documentation and/or other materials provided with the distribution.
        !            47:  * 3. All advertising materials mentioning features or use of this software
        !            48:  *    must display the following acknowledgement:
        !            49:  *     This product includes software developed by the University of
        !            50:  *     California, Berkeley and its contributors.
        !            51:  * 4. Neither the name of the University nor the names of its contributors
        !            52:  *    may be used to endorse or promote products derived from this software
        !            53:  *    without specific prior written permission.
        !            54:  *
        !            55:  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
        !            56:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
        !            57:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
        !            58:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
        !            59:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
        !            60:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
        !            61:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
        !            62:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
        !            63:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
        !            64:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
        !            65:  * SUCH DAMAGE.
        !            66:  */
        !            67: 
        !            68: 
        !            69: #import <string.h>
        !            70: #import <stdlib.h>
        !            71: #import <limits.h>
        !            72: #import <objc/objc.h>
        !            73: 
        !            74: static inline BOOL
        !            75: isupper(char c)
        !            76: {
        !            77:     return (c >= 'A' && c <= 'Z');
        !            78: }
        !            79: 
        !            80: static inline BOOL
        !            81: isalpha(char c)
        !            82: {
        !            83:     return ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z'));
        !            84: }
        !            85: 
        !            86: 
        !            87: static inline BOOL
        !            88: isspace(char c)
        !            89: {
        !            90:     return (c == ' ' || c == '\t' || c == '\n' || c == '\12');
        !            91: }
        !            92: 
        !            93: static inline BOOL
        !            94: isdigit(char c)
        !            95: {
        !            96:     return (c >= '0' && c <= '9');
        !            97: }
        !            98: 
        !            99: /*
        !           100:  * Convert a string to a long integer.
        !           101:  *
        !           102:  * Ignores `locale' stuff.  Assumes that the upper and lower case
        !           103:  * alphabets and digits are each contiguous.
        !           104:  */
        !           105: long
        !           106: strtol(nptr, endptr, base)
        !           107:        const char *nptr;
        !           108:        char **endptr;
        !           109:        register int base;
        !           110: {
        !           111:        register const char *s = nptr;
        !           112:        register unsigned long acc;
        !           113:        register int c;
        !           114:        register unsigned long cutoff;
        !           115:        register int neg = 0, any, cutlim;
        !           116: 
        !           117:        /*
        !           118:         * Skip white space and pick up leading +/- sign if any.
        !           119:         * If base is 0, allow 0x for hex and 0 for octal, else
        !           120:         * assume decimal; if base is already 16, allow 0x.
        !           121:         */
        !           122:        do {
        !           123:                c = *s++;
        !           124:        } while (isspace(c));
        !           125:        if (c == '-') {
        !           126:                neg = 1;
        !           127:                c = *s++;
        !           128:        } else if (c == '+')
        !           129:                c = *s++;
        !           130:        if ((base == 0 || base == 16) &&
        !           131:            c == '0' && (*s == 'x' || *s == 'X')) {
        !           132:                c = s[1];
        !           133:                s += 2;
        !           134:                base = 16;
        !           135:        } else if ((base == 0 || base == 2) &&
        !           136:            c == '0' && (*s == 'b' || *s == 'B')) {
        !           137:                c = s[1];
        !           138:                s += 2;
        !           139:                base = 2;
        !           140:        }
        !           141:        if (base == 0)
        !           142:                base = c == '0' ? 8 : 10;
        !           143: 
        !           144:        /*
        !           145:         * Compute the cutoff value between legal numbers and illegal
        !           146:         * numbers.  That is the largest legal value, divided by the
        !           147:         * base.  An input number that is greater than this value, if
        !           148:         * followed by a legal input character, is too big.  One that
        !           149:         * is equal to this value may be valid or not; the limit
        !           150:         * between valid and invalid numbers is then based on the last
        !           151:         * digit.  For instance, if the range for longs is
        !           152:         * [-2147483648..2147483647] and the input base is 10,
        !           153:         * cutoff will be set to 214748364 and cutlim to either
        !           154:         * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
        !           155:         * a value > 214748364, or equal but the next digit is > 7 (or 8),
        !           156:         * the number is too big, and we will return a range error.
        !           157:         *
        !           158:         * Set any if any `digits' consumed; make it negative to indicate
        !           159:         * overflow.
        !           160:         */
        !           161:        cutoff = neg ? -(unsigned long)LONG_MIN : LONG_MAX;
        !           162:        cutlim = cutoff % (unsigned long)base;
        !           163:        cutoff /= (unsigned long)base;
        !           164:        for (acc = 0, any = 0;; c = *s++) {
        !           165:                if (isdigit(c))
        !           166:                        c -= '0';
        !           167:                else if (isalpha(c))
        !           168:                        c -= isupper(c) ? 'A' - 10 : 'a' - 10;
        !           169:                else
        !           170:                        break;
        !           171:                if (c >= base)
        !           172:                        break;
        !           173:                if (any < 0 || acc > cutoff || acc == cutoff && c > cutlim)
        !           174:                        any = -1;
        !           175:                else {
        !           176:                        any = 1;
        !           177:                        acc *= base;
        !           178:                        acc += c;
        !           179:                }
        !           180:        }
        !           181:        if (any < 0) {
        !           182:                acc = neg ? LONG_MIN : LONG_MAX;
        !           183: //             errno = ERANGE;
        !           184:        } else if (neg)
        !           185:                acc = -acc;
        !           186:        if (endptr != 0)
        !           187:                *endptr = (char *)(any ? s - 1 : nptr);
        !           188:        return (acc);
        !           189: }
        !           190: 
        !           191: /*
        !           192:  * Convert a string to an unsigned long integer.
        !           193:  *
        !           194:  * Ignores `locale' stuff.  Assumes that the upper and lower case
        !           195:  * alphabets and digits are each contiguous.
        !           196:  */
        !           197: unsigned long
        !           198: strtoul(nptr, endptr, base)
        !           199:        const char *nptr;
        !           200:        char **endptr;
        !           201:        register int base;
        !           202: {
        !           203:        register const char *s = nptr;
        !           204:        register unsigned long acc;
        !           205:        register int c;
        !           206:        register unsigned long cutoff;
        !           207:        register int neg = 0, any, cutlim;
        !           208: 
        !           209:        /*
        !           210:         * See strtol for comments as to the logic used.
        !           211:         */
        !           212:        do {
        !           213:                c = *s++;
        !           214:        } while (isspace(c));
        !           215:        if (c == '-') {
        !           216:                neg = 1;
        !           217:                c = *s++;
        !           218:        } else if (c == '+')
        !           219:                c = *s++;
        !           220:        if ((base == 0 || base == 16) &&
        !           221:            c == '0' && (*s == 'x' || *s == 'X')) {
        !           222:                c = s[1];
        !           223:                s += 2;
        !           224:                base = 16;
        !           225:        } else if ((base == 0 || base == 2) &&
        !           226:            c == '0' && (*s == 'b' || *s == 'B')) {
        !           227:                c = s[1];
        !           228:                s += 2;
        !           229:                base = 2;
        !           230:        }
        !           231:        if (base == 0)
        !           232:                base = c == '0' ? 8 : 10;
        !           233:        cutoff = (unsigned long)ULONG_MAX / (unsigned long)base;
        !           234:        cutlim = (unsigned long)ULONG_MAX % (unsigned long)base;
        !           235:        for (acc = 0, any = 0;; c = *s++) {
        !           236:                if (isdigit(c))
        !           237:                        c -= '0';
        !           238:                else if (isalpha(c))
        !           239:                        c -= isupper(c) ? 'A' - 10 : 'a' - 10;
        !           240:                else
        !           241:                        break;
        !           242:                if (c >= base)
        !           243:                        break;
        !           244:                if (any < 0 || acc > cutoff || acc == cutoff && c > cutlim)
        !           245:                        any = -1;
        !           246:                else {
        !           247:                        any = 1;
        !           248:                        acc *= base;
        !           249:                        acc += c;
        !           250:                }
        !           251:        }
        !           252:        if (any < 0) {
        !           253:                acc = ULONG_MAX;
        !           254: //             errno = ERANGE;
        !           255:        } else if (neg)
        !           256:                acc = -acc;
        !           257:        if (endptr != 0)
        !           258:                *endptr = (char *)(any ? s - 1 : nptr);
        !           259:        return (acc);
        !           260: }

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