LibrePilot/flight/PiOS/Common/printf-stdarg.c

/**
 ******************************************************************************
 * @addtogroup PIOS PIOS Core hardware abstraction layer
 * @{
 *
 * @file       printf-stdarg.c   
 * @author     The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
 * 	       Parts by Thorsten Klose (tk@midibox.org)
 * @brief      Formatted print functions
 * @see        The GNU Public License (GPL) Version 3
 *
 *****************************************************************************/
/* 
 * This program is free software; you can redistribute it and/or modify 
 * it under the terms of the GNU General Public License as published by 
 * the Free Software Foundation; either version 3 of the License, or 
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful, but 
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 
 * for more details.
 * 
 * You should have received a copy of the GNU General Public License along 
 * with this program; if not, write to the Free Software Foundation, Inc., 
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */


/*
        putchar is the only external dependency for this file,
        if you have a working putchar, leave it commented out.
        If not, uncomment the define below and
        replace outbyte(c) by your own function call.

#define putchar(c) outbyte(c)
*/
//#define putchar(c) COMSendChar(c)

#include <pios.h>

static void printchar(char **str, int c)
{
        if (str) {
                **str = c;
                ++(*str);
        }
#ifdef PIOS_COM_DEBUG
        else PIOS_COM_SendChar(PIOS_COM_DEBUG, c);
#endif

}

#define PAD_RIGHT 1
#define PAD_ZERO 2

static int prints(char **out, const char *string, int width, int pad)
{
        register int pc = 0, padchar = ' ';

        if (width > 0) {
                register int len = 0;
                register const char *ptr;
                for (ptr = string; *ptr; ++ptr) ++len;
                if (len >= width) width = 0;
                else width -= len;
                if (pad & PAD_ZERO) padchar = '0';
        }
        if (!(pad & PAD_RIGHT)) {
                for ( ; width > 0; --width) {
                        printchar (out, padchar);
                        ++pc;
                }
        }
        for ( ; *string ; ++string) {
                printchar (out, *string);
                ++pc;
        }
        for ( ; width > 0; --width) {
                printchar (out, padchar);
                ++pc;
        }

        return pc;
}

/* the following should be enough for 32 bit int */
#define PRINT_BUF_LEN 12

static int printi(char **out, int i, int b, int sg, int width, int pad, int letbase)
{
        char print_buf[PRINT_BUF_LEN];
        register char *s;
        register int t, neg = 0, pc = 0;
        register unsigned int u = i;

        if (i == 0) {
                print_buf[0] = '0';
                print_buf[1] = '\0';
                return prints (out, print_buf, width, pad);
        }

        if (sg && b == 10 && i < 0) {
                neg = 1;
                u = -i;
        }

        s = print_buf + PRINT_BUF_LEN-1;
        *s = '\0';

        while (u) {
                t = u % b;
                if( t >= 10 )
                        t += letbase - '0' - 10;
                *--s = t + '0';
                u /= b;
        }

        if (neg) {
                if( width && (pad & PAD_ZERO) ) {
                        printchar (out, '-');
                        ++pc;
                        --width;
                }
                else {
                        *--s = '-';
                }
        }

        return pc + prints (out, s, width, pad);
}

static int print( char **out, const char *format, va_list args )
{
        register int width, pad;
        register int pc = 0;
        char scr[2];

        for (; *format != 0; ++format) {
                if (*format == '%') {
                        ++format;
                        width = pad = 0;
                        if (*format == '\0') break;
                        if (*format == '%') goto out;
                        if (*format == '-') {
                                ++format;
                                pad = PAD_RIGHT;
                        }
                        while (*format == '0') {
                                ++format;
                                pad |= PAD_ZERO;
                        }
                        for ( ; *format >= '0' && *format <= '9'; ++format) {
                                width *= 10;
                                width += *format - '0';
                        }
                        if( *format == 's' ) {
                                register char *s = (char *)va_arg( args, int );
                                pc += prints (out, s?s:"(null)", width, pad);
                                continue;
                        }
                        if( *format == 'd' ) {
                                pc += printi (out, va_arg( args, int ), 10, 1, width, pad, 'a');
                                continue;
                        }
                        if( *format == 'x' ) {
                                pc += printi (out, va_arg( args, int ), 16, 0, width, pad, 'a');
                                continue;
                        }
                        if( *format == 'X' ) {
                                pc += printi (out, va_arg( args, int ), 16, 0, width, pad, 'A');
                                continue;
                        }
                        if( *format == 'u' ) {
                                pc += printi (out, va_arg( args, int ), 10, 0, width, pad, 'a');
                                continue;
                        }
                        if( *format == 'c' ) {
                                /* char are converted to int then pushed on the stack */
                                scr[0] = (char)va_arg( args, int );
                                scr[1] = '\0';
                                pc += prints (out, scr, width, pad);
                                continue;
                        }
                }
                else {
                out:
                        printchar (out, *format);
                        ++pc;
                }
        }
        if (out) **out = '\0';
        va_end( args );
        return pc;
}

int printf(const char *format, ...)
{
        va_list args;
        
        va_start( args, format );
        return print( 0, format, args );
}

// TK: added for alternative parameter passing
int vprintf(const char *format, va_list args)
{
  return print( 0, format, args );
}

int sprintf(char *out, const char *format, ...)
{
        va_list args;
        
        va_start( args, format );
        return print( &out, format, args );
}

// TK: added for alternative parameter passing
int vsprintf(char *out, const char *format, va_list args)
{
  char *_out;
  _out = out;
  return print( &_out, format, args );
}


int snprintf( char *buf, size_t count, const char *format, ... )
{
        va_list args;
        
        ( void ) count;
        
        va_start( args, format );
        return print( &buf, format, args );
}

/**
  * @}
  */