bprintf.c

来自「开放源码的编译器open watcom 1.6.0版的源代码」· C语言 代码 · 共 140 行

/****************************************************************************
*
*                            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:  This module supports formatted output to a character buffer.
*               Both character and wide character formatting are included.
*       For added library granularity, this module could be split
*       into two, with "bprintf" functions in one file and the
*       "snprintf" functions in another.
*
*       C library functions:
*       _bprintf, _vbprintf
*       _bwprintf, _vbwprintf
*       _snprintf, _snwprintf
*       _vsnprintf, _vsnwprintf
*
****************************************************************************/


#include "variety.h"
#include "widechar.h"
#include <stdio.h>
#include <stdarg.h>
#include "printf.h"

struct  buf_limit {
    CHAR_TYPE   *bufptr;
    size_t      bufsize;
    int         bufover;
};

/*
 * buf_putc -- append a character to a string in memory
 */
static slib_callback_t buf_putc; // setup calling convention
static void __SLIB_CALLBACK buf_putc( SPECS __SLIB *specs, int op_char )
{
    struct buf_limit    *bufinfo;
    
    bufinfo = (struct buf_limit *)specs->_dest;
    if( specs->_output_count < bufinfo->bufsize ) {
        *( bufinfo->bufptr++ ) = op_char;
        specs->_output_count++;
    } else {
        bufinfo->bufover = -1;
    }
}

_WCRTLINK int __F_NAME(_vbprintf,_vbwprintf) ( CHAR_TYPE *s, size_t bufsize,
        const CHAR_TYPE *format, va_list arg)
{
    register int            len;
    auto struct buf_limit   bufinfo;
    slib_callback_t         *tmp;

    bufinfo.bufptr  = s;
    bufinfo.bufsize = bufsize - 1;
    bufinfo.bufover = 0;
#if defined( __386__ ) && defined( __QNX__ )
    /* avoid some segment relocations for 32-bit QNX */
    tmp = (void (*)())buf_putc;
#else
    tmp = buf_putc;
#endif
    len = __F_NAME(__prtf,__wprtf)( &bufinfo, format, arg, tmp );
    s[len] = '\0';
    return( len );
}

_WCRTLINK int __F_NAME(_bprintf,_bwprintf) ( CHAR_TYPE *dest, size_t bufsize,
            const CHAR_TYPE *format, ... )
{
    auto va_list    args;

    va_start( args, format );
    return( __F_NAME(_vbprintf,_vbwprintf)( dest, bufsize, format, args ) );
}

// Notes:
//  _vsnprintf, _vsnwprintf must return an error (-1) when buffer too small
//  If a NULL character can fit, append it. If not, no error.

_WCRTLINK int __F_NAME(_vsnprintf,_vsnwprintf) ( CHAR_TYPE *s, size_t bufsize,
        const CHAR_TYPE *format, va_list arg)
{
    register int            len;
    auto struct buf_limit   bufinfo;
    slib_callback_t         *tmp;

    bufinfo.bufptr  = s;
    bufinfo.bufsize = bufsize;
    bufinfo.bufover = 0;
#if defined( __386__ ) && defined( __QNX__ )
    /* avoid some segment relocations for 32-bit QNX */
    tmp = (void (*)())buf_putc;
#else
    tmp = buf_putc;
#endif
    len = __F_NAME(__prtf,__wprtf)( &bufinfo, format, arg, tmp );
    if( len < bufsize ) {
        s[len] = '\0';
    }
    if( bufinfo.bufover == 0 ) {
        return( len );
    } else {
        return( -1 );
    }
}

_WCRTLINK int __F_NAME(_snprintf,_snwprintf) ( CHAR_TYPE *dest, size_t bufsize,
            const CHAR_TYPE *format, ... )
{
    auto va_list    args;

    va_start( args, format );
    return( __F_NAME(_vsnprintf,_vsnwprintf)( dest, bufsize, format, args ) );
}