kolibrios/programs/develop/open watcom/trunk/clib/convert/strtol.c

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/****************************************************************************
*
* Open Watcom Project
*
* Portions Copyright (c) 1983-2002 Sybase, Inc. All Rights Reserved.
*
* ========================================================================
*
* This file contains Original Code and/or Modifications of Original
* Code as defined in and that are subject to the Sybase Open Watcom
* Public License version 1.0 (the 'License'). You may not use this file
* except in compliance with the License. BY USING THIS FILE YOU AGREE TO
* ALL TERMS AND CONDITIONS OF THE LICENSE. A copy of the License is
* provided with the Original Code and Modifications, and is also
* available at www.sybase.com/developer/opensource.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND SYBASE AND ALL CONTRIBUTORS HEREBY DISCLAIM
* ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR
* NON-INFRINGEMENT. Please see the License for the specific language
* governing rights and limitations under the License.
*
* ========================================================================
*
* Description: WHEN YOU FIGURE OUT WHAT THIS FILE DOES, PLEASE
* DESCRIBE IT HERE!
*
****************************************************************************/
#include "variety.h"
#include "widechar.h"
#include <stdio.h>
#include <stdlib.h>
#ifdef __WIDECHAR__
#include <wctype.h>
#else
#include <ctype.h>
#endif
#include <errno.h>
#include <limits.h>
#include "seterrno.h"
/*
* this table is the largest value that can safely be multiplied
* by the associated base without overflowing
*/
static unsigned long nearly_overflowing[] = {
ULONG_MAX / 2, ULONG_MAX / 3, ULONG_MAX / 4, ULONG_MAX / 5,
ULONG_MAX / 6, ULONG_MAX / 7, ULONG_MAX / 8, ULONG_MAX / 9,
ULONG_MAX / 10, ULONG_MAX / 11, ULONG_MAX / 12, ULONG_MAX / 13,
ULONG_MAX / 14, ULONG_MAX / 15, ULONG_MAX / 16, ULONG_MAX / 17,
ULONG_MAX / 18, ULONG_MAX / 19, ULONG_MAX / 20, ULONG_MAX / 21,
ULONG_MAX / 22, ULONG_MAX / 23, ULONG_MAX / 24, ULONG_MAX / 25,
ULONG_MAX / 26, ULONG_MAX / 27, ULONG_MAX / 28, ULONG_MAX / 29,
ULONG_MAX / 30, ULONG_MAX / 31, ULONG_MAX / 32, ULONG_MAX / 33,
ULONG_MAX / 34, ULONG_MAX / 35, ULONG_MAX / 36
};
#define hexstr(p) (p[0] == '0' && (p[1] == 'x' || p[1] == 'X'))
static int radix_value( CHAR_TYPE c )
{
if( c >= '0' && c <= '9' ) return( c - '0' );
c = __F_NAME(tolower,towlower)(c);
if( c >= 'a' && c <= 'i' ) return( c - 'a' + 10 );
if( c >= 'j' && c <= 'r' ) return( c - 'j' + 19 );
if( c >= 's' && c <= 'z' ) return( c - 's' + 28 );
return( 37 );
}
static unsigned long int _stol( const CHAR_TYPE *nptr,CHAR_TYPE **endptr,int base,int who)
{
const CHAR_TYPE *p;
const CHAR_TYPE *startp;
int digit;
unsigned long int value;
unsigned long int prev_value;
CHAR_TYPE sign;
char overflow; /*overflow is used as a flag so it does not
*need to be of type CHAR_TYPE */
if( endptr != NULL ) *endptr = (CHAR_TYPE *)nptr;
p = nptr;
while( __F_NAME(isspace,iswspace)(*p) ) ++p;
sign = *p;
if( sign == '+' || sign == '-' ) ++p;
if( base == 0 ) {
if( hexstr(p) ) base = 16;
else if( *p == '0' ) base = 8;
else base = 10;
}
if( base < 2 || base > 36 ) {
__set_errno( EDOM );
return( 0 );
}
if( base == 16 ) {
if( hexstr(p) ) p += 2; /* skip over '0x' */
}
startp = p;
overflow = 0;
value = 0;
for(;;) {
digit = radix_value( *p );
if( digit >= base ) break;
if( value > nearly_overflowing[base-2] ) overflow = 1;
prev_value = value;
value = value * base + digit;
if( value < prev_value ) overflow = 1;
++p;
}
if( p == startp ) p = nptr;
if( endptr != NULL ) *endptr = (CHAR_TYPE *)p;
if( who == 1 ) {
if( value >= 0x80000000 ) {
if( value == 0x80000000 && sign == '-' ) {
; /* OK */
} else {
overflow = 1;
}
}
}
if( overflow ) {
__set_errno( ERANGE );
if( who == 0 ) return( ULONG_MAX );
if( sign == '-' ) return( LONG_MIN );
return( LONG_MAX );
}
if( sign == '-' ) value = - value;
return( value );
}
_WCRTLINK unsigned long int __F_NAME(strtoul,wcstoul)( const CHAR_TYPE *nptr,
CHAR_TYPE **endptr, int base )
{
return( _stol( nptr, endptr, base, 0 ) );
}
_WCRTLINK long int __F_NAME(strtol,wcstol)( const CHAR_TYPE *nptr, CHAR_TYPE **endptr, int base )
{
return( _stol( nptr, endptr, base, 1 ) );
}