LibrePilot/flight/libraries/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);
}

/**
  * @}
  */