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/***
*wcstol.c - Contains C runtimes wcstol and wcstoul
*
* Copyright (c) 1989-1993, Microsoft Corporation. All rights reserved.
*
*Purpose:
* wcstol - convert wchar_t string to long signed integer
* wcstoul - convert wchar_t string to long unsigned integer
*
*Revision History:
* 06-15-92 KRS Module created, based on strtol.c
* 04-21-93 GJF Removed assumption that LONG_MIN == -LONG_MAX.
* 05-10-93 GJF Fixed error check.
* 05-20-93 GJF Nothing like taking ugly code and making prettier...
* and wrong. Fixed bug introduced on 5-10.
*
*******************************************************************************/
#include <cruntime.h>
#include <stdlib.h>
#include <limits.h>
#include <errno.h>
#include <ctype.h>
/***
*wcstol, wcstoul(nptr,endptr,ibase) - Convert ascii string to long un/signed
* int.
*
*Purpose:
* Convert an ascii string to a long 32-bit value. The base
* used for the caculations is supplied by the caller. The base
* must be in the range 0, 2-36. If a base of 0 is supplied, the
* ascii string must be examined to determine the base of the
* number:
* (a) First char = '0', second char = 'x' or 'X',
* use base 16.
* (b) First char = '0', use base 8
* (c) First char in range '1' - '9', use base 10.
*
* If the 'endptr' value is non-NULL, then wcstol/wcstoul places
* a pointer to the terminating character in this value.
* See ANSI standard for details
*
*Entry:
* nptr == NEAR/FAR pointer to the start of string.
* endptr == NEAR/FAR pointer to the end of the string.
* ibase == integer base to use for the calculations.
*
* string format: [whitespace] [sign] [0] [x] [digits/letters]
*
*Exit:
* Good return:
* result
*
* Overflow return:
* wcstol -- LONG_MAX or LONG_MIN
* wcstoul -- ULONG_MAX
* wcstol/wcstoul -- errno == ERANGE
*
* No digits or bad base return:
* 0
* endptr = nptr*
*
*Exceptions:
* None.
*******************************************************************************/
/* flag values */
#define FL_UNSIGNED 1 /* wcstoul called */
#define FL_NEG 2 /* negative sign found */
#define FL_OVERFLOW 4 /* overflow occured */
#define FL_READDIGIT 8 /* we've read at least one correct digit */
static unsigned long _CRTAPI3 wcstoxl (
const wchar_t *nptr,
const wchar_t **endptr,
int ibase,
int flags
)
{
const wchar_t *p;
wchar_t c;
unsigned long number;
unsigned digval;
unsigned long maxval;
p = nptr; /* p is our scanning pointer */
number = 0; /* start with zero */
c = *p++; /* read char */
while (iswspace(c))
c = *p++; /* skip whitespace */
if (c == '-') {
flags |= FL_NEG; /* remember minus sign */
c = *p++;
}
else if (c == '+')
c = *p++; /* skip sign */
if (ibase < 0 || ibase == 1 || ibase > 36) {
/* bad base! */
if (endptr)
/* store beginning of string in endptr */
*endptr = nptr;
return 0L; /* return 0 */
}
else if (ibase == 0) {
/* determine base free-lance, based on first two chars of
string */
if (c != L'0')
ibase = 10;
else if (*p == L'x' || *p == L'X')
ibase = 16;
else
ibase = 8;
}
if (ibase == 16) {
/* we might have 0x in front of number; remove if there */
if (c == L'0' && (*p == L'x' || *p == L'X')) {
++p;
c = *p++; /* advance past prefix */
}
}
/* if our number exceeds this, we will overflow on multiply */
maxval = ULONG_MAX / ibase;
for (;;) { /* exit in middle of loop */
/* convert c to value */
if (iswdigit(c))
digval = c - L'0';
else if (iswalpha(c))
digval = towupper(c) - L'A' + 10;
else
break;
if (digval >= (unsigned)ibase)
break; /* exit loop if bad digit found */
/* record the fact we have read one digit */
flags |= FL_READDIGIT;
/* we now need to compute number = number * base + digval,
but we need to know if overflow occured. This requires
a tricky pre-check. */
if (number < maxval || (number == maxval &&
(unsigned long)digval <= ULONG_MAX % ibase)) {
/* we won't overflow, go ahead and multiply */
number = number * ibase + digval;
}
else {
/* we would have overflowed -- set the overflow flag */
flags |= FL_OVERFLOW;
}
c = *p++; /* read next digit */
}
--p; /* point to place that stopped scan */
if (!(flags & FL_READDIGIT)) {
/* no number there; return 0 and point to beginning of
string */
if (endptr)
/* store beginning of string in endptr later on */
p = nptr;
number = 0L; /* return 0 */
}
else if ( (flags & FL_OVERFLOW) ||
( !(flags & FL_UNSIGNED) &&
( ( (flags & FL_NEG) && (number > -LONG_MIN) ) ||
( !(flags & FL_NEG) && (number > LONG_MAX) ) ) ) )
{
/* overflow or signed overflow occurred */
errno = ERANGE;
if ( flags & FL_UNSIGNED )
number = ULONG_MAX;
else if ( flags & FL_NEG )
number = (unsigned long)(-LONG_MIN);
else
number = LONG_MAX;
}
if (endptr != NULL)
/* store pointer to char that stopped the scan */
*endptr = p;
if (flags & FL_NEG)
/* negate result if there was a neg sign */
number = (unsigned long)(-(long)number);
return number; /* done. */
}
long _CRTAPI1 wcstol (
const wchar_t *nptr,
wchar_t **endptr,
int ibase
)
{
return (long) wcstoxl(nptr, endptr, ibase, 0);
}
unsigned long _CRTAPI1 wcstoul (
const wchar_t *nptr,
wchar_t **endptr,
int ibase
)
{
return wcstoxl(nptr, endptr, ibase, FL_UNSIGNED);
}
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