/*- * Copyright (c) 1990, 1993 * The Regents of the University of California. All rights reserved. * Copyright (c) 2005, Dmitry Xmelkov * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * $Id$ */ #include <limits.h> #include <ctype.h> #include <errno.h> #include <stdlib.h> #include "sectionname.h" /* * Convert a string to a long integer. * * Ignores `locale' stuff. Assumes that the upper and lower case * alphabets and digits are each contiguous. */ ATTRIBUTE_CLIB_SECTION long strtol(const char *nptr, char **endptr, register int base) { register unsigned long acc; register unsigned char c; register unsigned long cutoff; register signed char any; unsigned char flag = 0; #define FL_NEG 0x01 /* number is negative */ #define FL_0X 0x02 /* number has a 0x prefix */ if (endptr) *endptr = (char *)nptr; if (base != 0 && (base < 2 || base > 36)) return 0; /* * Skip white space and pick up leading +/- sign if any. * If base is 0, allow 0x for hex and 0 for octal, else * assume decimal; if base is already 16, allow 0x. */ do { c = *nptr++; } while (isspace(c)); if (c == '-') { flag = FL_NEG; c = *nptr++; } else if (c == '+') c = *nptr++; if ((base == 0 || base == 16) && c == '0' && (*nptr == 'x' || *nptr == 'X')) { c = nptr[1]; nptr += 2; base = 16; flag |= FL_0X; } if (base == 0) base = c == '0' ? 8 : 10; /* * Compute the cutoff value between legal numbers and illegal * numbers. That is the largest legal value, divided by the * base. An input number that is greater than this value, if * followed by a legal input character, is too big. One that * is equal to this value may be valid or not; the decision * about this is done as outlined below. * * Overflow detections works as follows: * * As: * acc_old <= cutoff * then: * acc_old * base <= 0x80000000 (unsigned) * then: * acc_old * base + c <= 0x80000000 + c * or: * acc_new <= 0x80000000 + 35 * * i.e. carry from MSB (by calculating acc_new) is impossible * and we can check result directly: * * if (acc_new > 0x80000000) then overflow * * Set any if any `digits' consumed; make it negative to indicate * overflow. */ #if LONG_MIN != -LONG_MAX - 1 # error "This implementation of strtol() does not work on this platform." #endif switch (base) { case 10: cutoff = ((unsigned long)LONG_MAX + 1) / 10; break; case 16: cutoff = ((unsigned long)LONG_MAX + 1) / 16; break; case 8: cutoff = ((unsigned long)LONG_MAX + 1) / 8; break; case 2: cutoff = ((unsigned long)LONG_MAX + 1) / 2; break; default: cutoff = ((unsigned long)LONG_MAX + 1) / base; } for (acc = 0, any = 0;; c = *nptr++) { if (c >= '0' && c <= '9') c -= '0'; else if (c >= 'A' && c <= 'Z') c -= 'A' - 10; else if (c >= 'a' && c <= 'z') c -= 'a' - 10; else break; if (c >= base) break; if (any < 0) continue; if (acc > cutoff) { any = -1; continue; } acc = acc * base + c; if (acc > (unsigned long)LONG_MAX + 1) any = -1; else any = 1; } if (endptr) { if (any) *endptr = (char *)nptr - 1; else if (flag & FL_0X) *endptr = (char *)nptr - 2; } if (any < 0) { acc = (flag & FL_NEG) ? LONG_MIN : LONG_MAX; errno = ERANGE; } else if (flag & FL_NEG) { acc = -acc; } else if ((signed long)acc < 0) { acc = LONG_MAX; errno = ERANGE; } return (acc); }