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initial import
This commit is contained in:
Roland McGrath
189
stdlib/strtol.c
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189
stdlib/strtol.c
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/* Copyright (C) 1991, 1992, 1994, 1995 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If
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not, write to the Free Software Foundation, Inc., 675 Mass Ave,
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Cambridge, MA 02139, USA. */
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#include <ctype.h>
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#include <limits.h>
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#include <stddef.h>
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#include <stdlib.h>
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#include <errno.h>
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/* Nonzero if we are defining `strtoul' or `strtouq', operating on unsigned
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integers. */
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#ifndef UNSIGNED
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#define UNSIGNED 0
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#endif
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/* If QUAD is defined, we are defining `strtoq' or `strtouq',
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operating on `long long int's. */
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#ifdef QUAD
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#if UNSIGNED
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#define strtoul strtouq
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#else
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#define strtol strtoq
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#endif
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#define LONG long long
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#undef LONG_MIN
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#define LONG_MIN LONG_LONG_MIN
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#undef LONG_MAX
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#define LONG_MAX LONG_LONG_MAX
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#undef ULONG_MAX
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#define ULONG_MAX ULONG_LONG_MAX
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#if __GNUC__ == 2 && __GNUC_MINOR__ < 7
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/* Work around gcc bug with using this constant. */
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static const unsigned long long int maxquad = ULONG_LONG_MAX;
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#undef ULONG_MAX
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#define ULONG_MAX maxquad
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#endif
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#else
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#define LONG long
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#endif
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/* Convert NPTR to an `unsigned long int' or `long int' in base BASE.
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If BASE is 0 the base is determined by the presence of a leading
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zero, indicating octal or a leading "0x" or "0X", indicating hexadecimal.
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If BASE is < 2 or > 36, it is reset to 10.
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If ENDPTR is not NULL, a pointer to the character after the last
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one converted is stored in *ENDPTR. */
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#if UNSIGNED
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unsigned LONG int
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#define strtol strtoul
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#else
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LONG int
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#endif
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strtol (nptr, endptr, base)
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const char *nptr;
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char **endptr;
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int base;
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{
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int negative;
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register unsigned LONG int cutoff;
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register unsigned int cutlim;
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register unsigned LONG int i;
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register const char *s;
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register unsigned char c;
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const char *save;
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int overflow;
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if (base < 0 || base == 1 || base > 36)
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base = 10;
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s = nptr;
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/* Skip white space. */
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while (isspace (*s))
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++s;
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if (*s == '\0')
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goto noconv;
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/* Check for a sign. */
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if (*s == '-')
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{
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negative = 1;
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++s;
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}
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else if (*s == '+')
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{
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negative = 0;
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++s;
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}
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else
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negative = 0;
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if (base == 16 && s[0] == '0' && toupper (s[1]) == 'X')
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s += 2;
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/* If BASE is zero, figure it out ourselves. */
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if (base == 0)
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if (*s == '0')
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{
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if (toupper (s[1]) == 'X')
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{
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s += 2;
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base = 16;
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}
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else
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base = 8;
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}
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else
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base = 10;
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/* Save the pointer so we can check later if anything happened. */
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save = s;
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cutoff = ULONG_MAX / (unsigned LONG int) base;
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cutlim = ULONG_MAX % (unsigned LONG int) base;
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overflow = 0;
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i = 0;
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for (c = *s; c != '\0'; c = *++s)
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{
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if (isdigit (c))
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c -= '0';
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else if (isalpha (c))
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c = toupper (c) - 'A' + 10;
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else
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break;
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if (c >= base)
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break;
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/* Check for overflow. */
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if (i > cutoff || (i == cutoff && c > cutlim))
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overflow = 1;
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else
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{
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i *= (unsigned LONG int) base;
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i += c;
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}
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}
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/* Check if anything actually happened. */
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if (s == save)
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goto noconv;
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/* Store in ENDPTR the address of one character
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past the last character we converted. */
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if (endptr != NULL)
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*endptr = (char *) s;
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#if !UNSIGNED
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/* Check for a value that is within the range of
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`unsigned LONG int', but outside the range of `LONG int'. */
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if (i > (negative ?
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-(unsigned LONG int) LONG_MIN : (unsigned LONG int) LONG_MAX))
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overflow = 1;
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#endif
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if (overflow)
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{
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errno = ERANGE;
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#if UNSIGNED
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return ULONG_MAX;
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#else
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return negative ? LONG_MIN : LONG_MAX;
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#endif
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}
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/* Return the result of the appropriate sign. */
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return (negative ? -i : i);
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noconv:
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/* There was no number to convert. */
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if (endptr != NULL)
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*endptr = (char *) nptr;
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return 0L;
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}
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