vswprint.c

C语言库函数的原型,有用的拿去

/***
*vswprint.c - print formatted data into a string from var arg list
*
*       Copyright (c) 1985-2001, Microsoft Corporation. All rights reserved.
*
*Purpose:
*       defines vswprintf(), _vswprintf_c and _vsnwprintf() - print formatted output to
*       a string, get the data from an argument ptr instead of explicit
*       arguments.
*
*******************************************************************************/


#include <cruntime.h>

/* This is prevent pulling in the inline
versions of (v)swprintf */
#define _INC_SWPRINTF_INL_

#include <stdio.h>
#include <wchar.h>
#include <dbgint.h>
#include <stdarg.h>
#include <internal.h>
#include <limits.h>
#include <mtdll.h>
#include <stddef.h>

#define MAXSTR INT_MAX


/***
*ifndef _COUNT_
*int _vswprintf(string, format, ap) - print formatted data to string from arg ptr
*else
*ifndef _SWPRINTFS_ERROR_RETURN_FIX
*int _vsnwprintf(string, cnt, format, ap) - print formatted data to string from arg ptr
*else
*int _vswprintf_c(string, cnt, format, ...) - print formatted data to string
*endif
*endif
*
*Purpose:
*       Prints formatted data, but to a string and gets data from an argument
*       pointer.
*       Sets up a FILE so file i/o operations can be used, make string look
*       like a huge buffer to it, but _flsbuf will refuse to flush it if it
*       fills up. Appends '\0' to make it a true string.
*
*       Allocate the 'fake' _iob[] entryit statically instead of on
*       the stack so that other routines can assume that _iob[] entries are in
*       are in DGROUP and, thus, are near.
*
*ifdef _COUNT_
*ifndef _SWPRINTFS_ERROR_RETURN_FIX
*       The _vsnwprintf() flavor takes a count argument that is
*       the max number of bytes that should be written to the
*       user's buffer.
*       We don't expose this function directly in the headers.
*else
*       The _vswprintf_c() flavor does the same thing as the _snwprintf
*       above, but, it also fixes a bug in the return value in the case
*       when there isn't enough space to write the null terminator
*       We don't fix this bug in _vsnwprintf because of backward
*       compatibility. In new code, however, _vsnwprintf is #defined to
*       _vswprintf_c so users get the bugfix.
*
*endif
*
*       Multi-thread: (1) Since there is no stream, this routine must never try
*       to get the stream lock (i.e., there is no stream lock either).  (2)
*       Also, since there is only one staticly allocated 'fake' iob, we must
*       lock/unlock to prevent collisions.
*
*Entry:
*       wchar_t *string - place to put destination string
*ifdef _COUNT_
*       size_t count - max number of bytes to put in buffer
*endif
*       wchar_t *format - format string, describes format of data
*       va_list ap - varargs argument pointer
*
*Exit:
*       returns number of wide characters in string
*       returns -2 if the string has been truncated (only in _vsnprintf_helper)
*       returns -1 in other error cases
*
*Exceptions:
*
*******************************************************************************/

#ifndef _COUNT_

int __cdecl _vswprintf_l (
        wchar_t *string,
        const wchar_t *format,
        _locale_t plocinfo,
        va_list ap
        )
#else  /* _COUNT_ */

#ifndef _SWPRINTFS_ERROR_RETURN_FIX
/* Here we implement _vsnwprintf without the
return value bugfix */

int __cdecl _vsnwprintf_l (
        wchar_t *string,
        size_t count,
        const wchar_t *format,
        _locale_t plocinfo,
        va_list ap
        )
#else  /* _SWPRINTFS_ERROR_RETURN_FIX */
int __cdecl _vswprintf_helper (
        WOUTPUTFN woutfn,
        wchar_t *string,
        size_t count,
        const wchar_t *format,
        _locale_t plocinfo,
        va_list ap
        )
#endif  /* _SWPRINTFS_ERROR_RETURN_FIX */
#endif  /* _COUNT_ */

{
        FILE str = { 0 };
        REG1 FILE *outfile = &str;
        REG2 int retval;

        _VALIDATE_RETURN( (format != NULL), EINVAL, -1);

#ifdef _COUNT_
        _VALIDATE_RETURN( (count == 0) || (string != NULL), EINVAL, -1 );
#else  /* _COUNT_ */
        _VALIDATE_RETURN( (string != NULL), EINVAL, -1 );
#endif  /* _COUNT_ */

        outfile->_flag = _IOWRT|_IOSTRG;
        outfile->_ptr = outfile->_base = (char *) string;
#ifndef _COUNT_
        outfile->_cnt = MAXSTR;
#else  /* _COUNT_ */
        if(count>(INT_MAX/sizeof(wchar_t)))
        {
           /* old-style functions allow any large value to mean unbounded */
           outfile->_cnt = INT_MAX;
        }
        else
        {
            outfile->_cnt = (int)(count*sizeof(wchar_t));
        }
#endif  /* _COUNT_ */

#ifndef _SWPRINTFS_ERROR_RETURN_FIX
        retval = _woutput_l(outfile, format, plocinfo, ap );
#else  /* _SWPRINTFS_ERROR_RETURN_FIX */
        retval = woutfn(outfile, format, plocinfo, ap );
#endif  /* _SWPRINTFS_ERROR_RETURN_FIX */

        if(string==NULL)
        {
            return retval;
        }

#ifndef _SWPRINTFS_ERROR_RETURN_FIX
        _putc_nolock('\0',outfile);     /* no-lock version */
        _putc_nolock('\0',outfile);     /* 2nd byte for wide char version */

        return(retval);
#else  /* _SWPRINTFS_ERROR_RETURN_FIX */
        if((retval >= 0) && (_putc_nolock('\0',outfile) != EOF) && (_putc_nolock('\0',outfile) != EOF))
            return(retval);

        string[count - 1] = 0;
        if (outfile->_cnt < 0)
        {
            /* the buffer was too small; we return -2 to indicate truncation */
            return -2;
        }
        return -1;
#endif  /* _SWPRINTFS_ERROR_RETURN_FIX */

}

#ifndef _COUNT_

int __cdecl _vswprintf (
        wchar_t *string,
        const wchar_t *format,
        va_list ap
        )
{
#pragma warning(push)
#pragma warning(disable:4996)
    return _vswprintf_l(string, format, NULL, ap);
#pragma warning(pop)
}

int __cdecl __vswprintf_l (
        wchar_t *string,
        const wchar_t *format,
        _locale_t _Plocinfo,
        va_list ap
        )
{
#pragma warning(push)
#pragma warning(disable:4996)
    return _vswprintf_l(string, format, _Plocinfo, ap);
#pragma warning(pop)
}

#else  /* _COUNT_ */

#ifndef _SWPRINTFS_ERROR_RETURN_FIX
/* Here we implement _vsnwprintf without the
return value bugfix */

int __cdecl _vsnwprintf (
        wchar_t *string,
        size_t count,
        const wchar_t *format,
        va_list ap
        )
{
    #pragma warning(push)
    #pragma warning(disable:4996) // Disable deprecation warning since calling function is also deprecated
    return _vsnwprintf_l(string, count, format, NULL, ap);
    #pragma warning(pop)
}
#endif  /* _SWPRINTFS_ERROR_RETURN_FIX */
#endif  /* _COUNT_ */


#ifdef _SWPRINTFS_ERROR_RETURN_FIX
int __cdecl _vswprintf_c (
        wchar_t *string,
        size_t count,
        const wchar_t *format,
        va_list ap
        )
{
    int retval = _vswprintf_helper(_woutput_l, string, count, format, NULL, ap);
    return (retval < 0 ? -1 : retval);
}

int __cdecl _vswprintf_c_l (
        wchar_t *string,
        size_t count,
        const wchar_t *format,
        _locale_t plocinfo,
        va_list ap
        )
{
    int retval = _vswprintf_helper(_woutput_l, string, count, format, plocinfo, ap);
    return (retval < 0 ? -1 : retval);
}

int __cdecl _vswprintf_s_l (
        wchar_t *string,
        size_t sizeInWords,
        const wchar_t *format,
        _locale_t plocinfo,
        va_list ap
        )
{
    int retvalue = -1;

    /* validation section */
    _VALIDATE_RETURN(format != NULL, EINVAL, -1);
    _VALIDATE_RETURN(string != NULL && sizeInWords > 0, EINVAL, -1);

    retvalue = _vswprintf_helper(_woutput_s_l, string, sizeInWords, format, plocinfo, ap);
    if (retvalue < 0)
    {
        string[0] = 0;
        _SECURECRT__FILL_STRING(string, sizeInWords, 1);
    }
    if (retvalue == -2)
    {
        _VALIDATE_RETURN(("Buffer too small", 0), ERANGE, -1);
    }
    if (retvalue >= 0)
    {
        _SECURECRT__FILL_STRING(string, sizeInWords, retvalue + 1);
    }

    return retvalue;
}

int __cdecl vswprintf_s (
        wchar_t *string,
        size_t sizeInWords,
        const wchar_t *format,
        va_list ap
        )
{
    return _vswprintf_s_l(string, sizeInWords, format, NULL, ap);
}

int __cdecl _vsnwprintf_s_l (
        wchar_t *string,
        size_t sizeInWords,
        size_t count,
        const wchar_t *format,
        _locale_t plocinfo,
        va_list ap
        )
{
    int retvalue = -1;
    errno_t save_errno = 0;

    /* validation section */
    _VALIDATE_RETURN(format != NULL, EINVAL, -1);
    if (count == 0 && string == NULL && sizeInWords == 0)
    {
        /* this case is allowed; nothing to do */
        return 0;
    }
    _VALIDATE_RETURN(string != NULL && sizeInWords > 0, EINVAL, -1);

    if (sizeInWords > count)
    {
        save_errno = errno;
        retvalue = _vswprintf_helper(_woutput_s_l, string, count + 1, format, plocinfo, ap);
        if (retvalue == -2)
        {
            /* the string has been truncated, return -1 */
            _SECURECRT__FILL_STRING(string, sizeInWords, count + 1);
            if (errno == ERANGE)
            {
                errno = save_errno;
            }
            return -1;
        }
    }
    else /* sizeInWords <= count */
    {
        save_errno = errno;
        retvalue = _vswprintf_helper(_woutput_s_l, string, sizeInWords, format, plocinfo, ap);
        string[sizeInWords - 1] = 0;
        /* we allow truncation if count == _TRUNCATE */
        if (retvalue == -2 && count == _TRUNCATE)
        {
            if (errno == ERANGE)
            {
                errno = save_errno;
            }
            return -1;
        }
    }

    if (retvalue < 0)
    {
        string[0] = 0;
        _SECURECRT__FILL_STRING(string, sizeInWords, 1);
        if (retvalue == -2)
        {
            _VALIDATE_RETURN(("Buffer too small", 0), ERANGE, -1);
        }
        return -1;
    }

    _SECURECRT__FILL_STRING(string, sizeInWords, retvalue + 1);

    return (retvalue < 0 ? -1 : retvalue);
}

int __cdecl _vsnwprintf_s (
        wchar_t *string,
        size_t sizeInWords,
        size_t count,
        const wchar_t *format,
        va_list ap
        )
{
    return _vsnwprintf_s_l(string, sizeInWords, count, format, NULL, ap);
}

int __cdecl _vswprintf_p (
        wchar_t *string,
        size_t count,
        const wchar_t *format,
        va_list ap
        )
{
    int retval = _vswprintf_helper(_woutput_p_l, string, count, format, NULL, ap);
    return (retval < 0 ? -1 : retval);
}

int __cdecl _vswprintf_p_l (
        wchar_t *string,
        size_t count,
        const wchar_t *format,
        _locale_t plocinfo,
        va_list ap
        )
{
    int retval = _vswprintf_helper(_woutput_p_l, string, count, format, plocinfo, ap);
    return (retval < 0 ? -1 : retval);
}

#endif  /* _SWPRINTFS_ERROR_RETURN_FIX */

/***
* _vscwprintf() - counts the number of character needed to print the formatted
* data
*
*Purpose:
*       Counts the number of characters in the fotmatted data.
*
*Entry:
*       wchar_t *format - format string, describes format of data
*       va_list ap - varargs argument pointer
*
*Exit:
*       returns number of characters needed to print formatted data.
*
*Exceptions:
*
*******************************************************************************/


#ifndef _COUNT_
int __cdecl _vscwprintf_helper (
        WOUTPUTFN outfn,
        const wchar_t *format,
        _locale_t plocinfo,
        va_list ap
        )
{
        FILE str = { 0 };
        REG1 FILE *outfile = &str;
        REG2 int retval;

        _VALIDATE_RETURN( (format != NULL), EINVAL, -1);

        outfile->_cnt = MAXSTR;
        outfile->_flag = _IOWRT|_IOSTRG;
        outfile->_ptr = outfile->_base = NULL;

        retval = outfn(outfile, format, plocinfo, ap);
        return(retval);
}

int __cdecl _vscwprintf (
        const wchar_t *format,
        va_list ap
        )
{
        return _vscwprintf_helper(_woutput_l, format, NULL, ap);
}

int __cdecl _vscwprintf_l (
        const wchar_t *format,
        _locale_t plocinfo,
        va_list ap
        )
{
        return _vscwprintf_helper(_woutput_l, format, plocinfo, ap);
}

int __cdecl _vscwprintf_p (
        const wchar_t *format,
        va_list ap
        )
{
        return _vscwprintf_helper(_woutput_p_l, format, NULL, ap);
}

int __cdecl _vscwprintf_p_l (
        const wchar_t *format,
        _locale_t plocinfo,
        va_list ap
        )
{
        return _vscwprintf_helper(_woutput_p_l, format, plocinfo, ap);
}

#endif  /* _COUNT_ */