Annotation of gforth/engine/strtol.c, revision 1.1
1.1 ! anton 1: /* Copyright (C) 1991, 1992 Free Software Foundation, Inc.
! 2: This file is part of the GNU C Library.
! 3:
! 4: The GNU C Library is free software; you can redistribute it and/or
! 5: modify it under the terms of the GNU Library General Public License as
! 6: published by the Free Software Foundation; either version 2 of the
! 7: License, or (at your option) any later version.
! 8:
! 9: The GNU C Library is distributed in the hope that it will be useful,
! 10: but WITHOUT ANY WARRANTY; without even the implied warranty of
! 11: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
! 12: Library General Public License for more details.
! 13:
! 14: You should have received a copy of the GNU Library General Public
! 15: License along with the GNU C Library; see the file COPYING.LIB. If
! 16: not, write to the Free Software Foundation, Inc., 675 Mass Ave,
! 17: Cambridge, MA 02139, USA. */
! 18:
! 19: #include "ansidecl.h"
! 20: #include <ctype.h>
! 21: #include <limits.h>
! 22: #include <stddef.h>
! 23: #include <stdlib.h>
! 24: /* errno.h is needed on SunOS 4.1.2 */
! 25: #include <errno.h>
! 26:
! 27: #ifndef UNSIGNED
! 28: #define UNSIGNED 0
! 29: #endif
! 30:
! 31: /* Convert NPTR to an `unsigned long int' or `long int' in base BASE.
! 32: If BASE is 0 the base is determined by the presence of a leading
! 33: zero, indicating octal or a leading "0x" or "0X", indicating hexadecimal.
! 34: If BASE is < 2 or > 36, it is reset to 10.
! 35: If ENDPTR is not NULL, a pointer to the character after the last
! 36: one converted is stored in *ENDPTR. */
! 37: #if UNSIGNED
! 38: unsigned long int
! 39: #define strtol strtoul
! 40: #else
! 41: long int
! 42: #endif
! 43: DEFUN(strtol, (nptr, endptr, base),
! 44: CONST char *nptr AND char **endptr AND int base)
! 45: {
! 46: int negative;
! 47: register unsigned long int cutoff;
! 48: register unsigned int cutlim;
! 49: register unsigned long int i;
! 50: register CONST char *s;
! 51: register unsigned char c;
! 52: CONST char *save;
! 53: int overflow;
! 54:
! 55: if (base < 0 || base == 1 || base > 36)
! 56: base = 10;
! 57:
! 58: s = nptr;
! 59:
! 60: /* Skip white space. */
! 61: while (isspace(*s))
! 62: ++s;
! 63: if (*s == '\0')
! 64: goto noconv;
! 65:
! 66: /* Check for a sign. */
! 67: if (*s == '-')
! 68: {
! 69: negative = 1;
! 70: ++s;
! 71: }
! 72: else if (*s == '+')
! 73: {
! 74: negative = 0;
! 75: ++s;
! 76: }
! 77: else
! 78: negative = 0;
! 79:
! 80: if (base == 16 && s[0] == '0' && toupper(s[1]) == 'X')
! 81: s += 2;
! 82:
! 83: /* If BASE is zero, figure it out ourselves. */
! 84: if (base == 0)
! 85: if (*s == '0')
! 86: {
! 87: if (toupper(s[1]) == 'X')
! 88: {
! 89: s += 2;
! 90: base = 16;
! 91: }
! 92: else
! 93: base = 8;
! 94: }
! 95: else
! 96: base = 10;
! 97:
! 98: /* Save the pointer so we can check later if anything happened. */
! 99: save = s;
! 100:
! 101: cutoff = ULONG_MAX / (unsigned long int) base;
! 102: cutlim = ULONG_MAX % (unsigned long int) base;
! 103:
! 104: overflow = 0;
! 105: i = 0;
! 106: for (c = *s; c != '\0'; c = *++s)
! 107: {
! 108: if (isdigit(c))
! 109: c -= '0';
! 110: else if (isalpha(c))
! 111: c = toupper(c) - 'A' + 10;
! 112: else
! 113: break;
! 114: if (c >= base)
! 115: break;
! 116: /* Check for overflow. */
! 117: if (i > cutoff || (i == cutoff && c > cutlim))
! 118: overflow = 1;
! 119: else
! 120: {
! 121: i *= (unsigned long int) base;
! 122: i += c;
! 123: }
! 124: }
! 125:
! 126: /* Check if anything actually happened. */
! 127: if (s == save)
! 128: goto noconv;
! 129:
! 130: /* Store in ENDPTR the address of one character
! 131: past the last character we converted. */
! 132: if (endptr != NULL)
! 133: *endptr = (char *) s;
! 134:
! 135: #if !UNSIGNED
! 136: /* Check for a value that is within the range of
! 137: `unsigned long int', but outside the range of `long int'. */
! 138: if (i > (negative ?
! 139: - (unsigned long int) LONG_MIN : (unsigned long int) LONG_MAX))
! 140: overflow = 1;
! 141: #endif
! 142:
! 143: if (overflow)
! 144: {
! 145: errno = ERANGE;
! 146: #if UNSIGNED
! 147: return ULONG_MAX;
! 148: #else
! 149: return negative ? LONG_MIN : LONG_MAX;
! 150: #endif
! 151: }
! 152:
! 153: /* Return the result of the appropriate sign. */
! 154: return (negative ? - i : i);
! 155:
! 156: noconv:
! 157: /* There was no number to convert. */
! 158: if (endptr != NULL)
! 159: *endptr = (char *) nptr;
! 160: return 0L;
! 161: }
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