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Diffstat (limited to 'stdlib/strtol.c')
| -rw-r--r-- | stdlib/strtol.c | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/stdlib/strtol.c b/stdlib/strtol.c new file mode 100644 index 0000000000..888a94e4d7 --- /dev/null +++ b/stdlib/strtol.c @@ -0,0 +1,189 @@ +/* Copyright (C) 1991, 1992, 1994, 1995 Free Software Foundation, Inc. + +This file is part of the GNU C Library. + +The GNU C Library is free software; you can redistribute it and/or +modify it under the terms of the GNU Library General Public License as +published by the Free Software Foundation; either version 2 of the +License, or (at your option) any later version. + +The GNU C Library is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 675 Mass Ave, +Cambridge, MA 02139, USA. */ + +#include <ctype.h> +#include <limits.h> +#include <stddef.h> +#include <stdlib.h> +#include <errno.h> + +/* Nonzero if we are defining `strtoul' or `strtouq', operating on unsigned + integers. */ +#ifndef UNSIGNED +#define UNSIGNED 0 +#endif + +/* If QUAD is defined, we are defining `strtoq' or `strtouq', + operating on `long long int's. */ +#ifdef QUAD +#if UNSIGNED +#define strtoul strtouq +#else +#define strtol strtoq +#endif +#define LONG long long +#undef LONG_MIN +#define LONG_MIN LONG_LONG_MIN +#undef LONG_MAX +#define LONG_MAX LONG_LONG_MAX +#undef ULONG_MAX +#define ULONG_MAX ULONG_LONG_MAX +#if __GNUC__ == 2 && __GNUC_MINOR__ < 7 +/* Work around gcc bug with using this constant. */ +static const unsigned long long int maxquad = ULONG_LONG_MAX; +#undef ULONG_MAX +#define ULONG_MAX maxquad +#endif +#else +#define LONG long +#endif + +/* Convert NPTR to an `unsigned long int' or `long int' in base BASE. + If BASE is 0 the base is determined by the presence of a leading + zero, indicating octal or a leading "0x" or "0X", indicating hexadecimal. + If BASE is < 2 or > 36, it is reset to 10. + If ENDPTR is not NULL, a pointer to the character after the last + one converted is stored in *ENDPTR. */ +#if UNSIGNED +unsigned LONG int +#define strtol strtoul +#else +LONG int +#endif +strtol (nptr, endptr, base) + const char *nptr; + char **endptr; + int base; +{ + int negative; + register unsigned LONG int cutoff; + register unsigned int cutlim; + register unsigned LONG int i; + register const char *s; + register unsigned char c; + const char *save; + int overflow; + + if (base < 0 || base == 1 || base > 36) + base = 10; + + s = nptr; + + /* Skip white space. */ + while (isspace (*s)) + ++s; + if (*s == '\0') + goto noconv; + + /* Check for a sign. */ + if (*s == '-') + { + negative = 1; + ++s; + } + else if (*s == '+') + { + negative = 0; + ++s; + } + else + negative = 0; + + if (base == 16 && s[0] == '0' && toupper (s[1]) == 'X') + s += 2; + + /* If BASE is zero, figure it out ourselves. */ + if (base == 0) + if (*s == '0') + { + if (toupper (s[1]) == 'X') + { + s += 2; + base = 16; + } + else + base = 8; + } + else + base = 10; + + /* Save the pointer so we can check later if anything happened. */ + save = s; + + cutoff = ULONG_MAX / (unsigned LONG int) base; + cutlim = ULONG_MAX % (unsigned LONG int) base; + + overflow = 0; + i = 0; + for (c = *s; c != '\0'; c = *++s) + { + if (isdigit (c)) + c -= '0'; + else if (isalpha (c)) + c = toupper (c) - 'A' + 10; + else + break; + if (c >= base) + break; + /* Check for overflow. */ + if (i > cutoff || (i == cutoff && c > cutlim)) + overflow = 1; + else + { + i *= (unsigned LONG int) base; + i += c; + } + } + + /* Check if anything actually happened. */ + if (s == save) + goto noconv; + + /* Store in ENDPTR the address of one character + past the last character we converted. */ + if (endptr != NULL) + *endptr = (char *) s; + +#if !UNSIGNED + /* Check for a value that is within the range of + `unsigned LONG int', but outside the range of `LONG int'. */ + if (i > (negative ? + -(unsigned LONG int) LONG_MIN : (unsigned LONG int) LONG_MAX)) + overflow = 1; +#endif + + if (overflow) + { + errno = ERANGE; +#if UNSIGNED + return ULONG_MAX; +#else + return negative ? LONG_MIN : LONG_MAX; +#endif + } + + /* Return the result of the appropriate sign. */ + return (negative ? -i : i); + +noconv: + /* There was no number to convert. */ + if (endptr != NULL) + *endptr = (char *) nptr; + return 0L; +} |