Leaked source code of windows server 2003
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/***
*wcstod.c - convert wide char string to floating point number
*
* Copyright (c) 1985-2001, Microsoft Corporation. All rights reserved.
*
*Purpose:
* Convert character string to floating point number
*
*Revision History:
* 06-15-92 KRS Created from strtod.c.
* 11-06-92 KRS Fix bugs in wctomb() loop.
* 04-06-93 SKS Replace _CRTAPI* with _cdecl
* 02-07-94 CFW POSIXify.
* 09-06-94 CFW Replace MTHREAD with _MT.
* 01-10-95 CFW Debug CRT allocs.
* 04-01-96 BWT POSIX work.
* 02-19-01 GB added _alloca and Check for return value of _malloc_crt
*
*******************************************************************************/
#include <cruntime.h>
#include <internal.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>
#include <math.h>
#include <dbgint.h>
#include <stdlib.h>
#include <malloc.h>
#include <fltintrn.h>
/***
*double wcstod(nptr, endptr) - convert wide string to double
*
*Purpose:
* wcstod recognizes an optional string of tabs and spaces,
* then an optional sign, then a string of digits optionally
* containing a decimal point, then an optional e or E followed
* by an optionally signed integer, and converts all this to
* to a floating point number. The first unrecognized
* character ends the string, and is pointed to by endptr.
*
*Entry:
* nptr - pointer to wide string to convert
*
*Exit:
* returns value of wide character string
* wchar_t **endptr - if not NULL, points to character which stopped
* the scan
*
*Exceptions:
*
*******************************************************************************/
double __cdecl wcstod (
const wchar_t *nptr,
REG2 wchar_t **endptr
)
{
#ifdef _MT
struct _flt answerstruct;
#endif
FLT answer;
double tmp;
unsigned int flags;
REG1 wchar_t *ptr = (wchar_t *) nptr;
char * cptr;
int malloc_flag = 0;
int retval, len;
int clen = 0;
/* scan past leading space/tab characters */
while (iswspace(*ptr))
ptr++;
__try{
cptr = (char *)_alloca((wcslen(ptr)+1) * sizeof(wchar_t));
}
__except(1){ //EXCEPTION_EXECUTE_HANDLER
_resetstkoflw();
if ((cptr = (char *)_malloc_crt((wcslen(ptr)+1) * sizeof(wchar_t))) == NULL)
{
errno = ENOMEM;
return 0.0;
}
malloc_flag = 1;
}
// UNDONE: check for errors
for (len = 0; ptr[len]; len++)
{
if ((retval = wctomb(cptr+len,ptr[len]))<=0)
break;
clen += retval;
}
cptr[clen++] = '\0';
/* let _fltin routine do the rest of the work */
#ifdef _MT
/* ok to take address of stack variable here; fltin2 knows to use ss */
answer = _fltin2( &answerstruct, cptr, clen, 0, 0);
#else
answer = _fltin(cptr, clen, 0, 0);
#endif
if (malloc_flag)
_free_crt(cptr);
if ( endptr != NULL )
*endptr = (wchar_t *) ptr + answer->nbytes;
/* UNDONE: assumes no multi-byte chars in string */
flags = answer->flags;
if ( flags & (512 | 64)) {
/* no digits found or invalid format:
ANSI says return 0.0, and *endptr = nptr */
tmp = 0.0;
if ( endptr != NULL )
*endptr = (wchar_t *) nptr;
}
else if ( flags & (128 | 1) ) {
if ( *ptr == '-' )
tmp = -HUGE_VAL; /* negative overflow */
else
tmp = HUGE_VAL; /* positive overflow */
errno = ERANGE;
}
else if ( flags & 256 ) {
tmp = 0.0; /* underflow */
errno = ERANGE;
}
else
tmp = answer->dval;
return(tmp);
}