doprnt.cc

Murphy 大俠 GPL 的 C++/x86 RTOS, 支持 MMU, 用戶/核心 模式區隔. http://hpc.ee.ntu.edu.tw/~murphy/me/EKernel.html

/* 
 * Mach Operating System
 * Copyright (c) 1991,1990,1989 Carnegie Mellon University
 * All Rights Reserved.
 * 
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 * 
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 * 
 * Carnegie Mellon requests users of this software to return to
 * 
 *  Software Distribution Coordinator  or  [e-mail]
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 * 
 * any improvements or extensions that they make and grant Carnegie Mellon
 * the rights to redistribute these changes.
 */


/*
 *  Common code for printf et al.
 *
 *  The calling routine typically takes a variable number of arguments,
 *  and passes the address of the first one.  This implementation
 *  assumes a straightforward, stack implementation, aligned to the
 *  machine's wordsize.  Increasing addresses are assumed to point to
 *  successive arguments (left-to-right), as is the case for a machine
 *  with a downward-growing stack with arguments pushed right-to-left.
 *
 *  To write, for example, fprintf() using this routine, the code
 *
 *	fprintf(fd, format, args)
 *	FILE *fd;
 *	char *format;
 *	{
 *	_doprnt(format, &args, fd);
 *	}
 *
 *  would suffice.  (This example does not handle the fprintf's "return
 *  value" correctly, but who looks at the return value of fprintf
 *  anyway?)
 *
 *  This version implements the following printf features:
 *
 *	%d	decimal conversion
 *	%u	unsigned conversion
 *	%x	hexadecimal conversion
 *	%X	hexadecimal conversion with capital letters
 *	%o	octal conversion
 *	%c	character
 *	%s	string
 *	%m.n	field width, precision
 *	%-m.n	left adjustment
 *	%0m.n	zero-padding
 *	%*.*	width and precision taken from arguments
 *
 *  This version does not implement %f, %e, or %g.  It accepts, but
 *  ignores, an `l' as in %ld, %lo, %lx, and %lu, and therefore will not
 *  work correctly on machines for which sizeof(long) != sizeof(int).
 *  It does not even parse %D, %O, or %U; you should be using %ld, %o and
 *  %lu if you mean long conversion.
 *
 *  As mentioned, this version does not return any reasonable value.
 *
 *  Permission is granted to use, modify, or propagate this code as
 *  long as this notice is incorporated.
 *
 *  Steve Summit 3/25/87
 */

/*
 * Added for general use:
 *	#	prefix for alternate format:
 *		0x (0X) for hex
 *		leading 0 for octal
 *	+	print '+' if positive
 *	blank	print ' ' if positive
 *
 *	z	signed hexadecimal
 *	r	signed, 'radix'
 *	n	unsigned, 'radix'
 *
 *	D,U,O,Z	same as corresponding lower-case versions
 *		(compatibility)
 */
/*
 *	Added ANSI %p for pointers.  Output looks like 0x%08x.
 */

#include <stdarg.h>
#include "types.h"

static int isdigit(int d)
{
	return ( d>='0' && d<='9' );
}

const static int MAXBUF=32;		// enough for binary

const static char digits[] = "0123456789abcdef";

boolean_t	_doprnt_truncates = FALSE;

void _doprnt(
	register const char *fmt,
	va_list		args,
	int		radix,							// default radix - for '%r'
 	void		(*putc)(char *arg, int c),	// character output
	char		*putc_arg					// argument for putc
)
{
	int		length;
	int		prec;
	boolean_t	ladjust;
	char		padc;
	long		n;
	unsigned long	u;
	int		plus_sign;
	int		sign_char;
	boolean_t	altfmt, truncate;
	int		base;
	char		c;

	while (*fmt != '\0') {
		if (*fmt != '%') {
			(*putc)(putc_arg, *fmt++);
			continue;
	    }

	    fmt++;

	    length = 0;
	    prec = -1;
	    ladjust = FALSE;
	    padc = ' ';
	    plus_sign = 0;
	    sign_char = 0;
	    altfmt = FALSE;

	    while (TRUE) {
		if (*fmt == '#') {
		    altfmt = TRUE;
		    fmt++;
		}
		else if (*fmt == '-') {
		    ladjust = TRUE;
		    fmt++;
		}
		else if (*fmt == '+') {
		    plus_sign = '+';
		    fmt++;
		}
		else if (*fmt == ' ') {
		    if (plus_sign == 0)
			plus_sign = ' ';
		    fmt++;
		}
		else
		    break;
	    }

	    if (*fmt == '0') {
		padc = '0';
		fmt++;
	    }

	    if (isdigit(*fmt)) {
		while(isdigit(*fmt))
		    length = 10 * length + ((*fmt++)-'0');
	    }
	    else if (*fmt == '*') {
		length = va_arg(args, int);
		fmt++;
		if (length < 0) {
		    ladjust = !ladjust;
		    length = -length;
		}
	    }

	    if (*fmt == '.') {
		fmt++;
		if (isdigit(*fmt)) {
		    prec = 0;
		    while(isdigit(*fmt))
			prec = 10 * prec + ((*fmt++)-'0');
		}
		else if (*fmt == '*') {
		    prec = va_arg(args, int);
		    fmt++;
		}
	    }

	    if (*fmt == 'l')
		fmt++;	/* need it if sizeof(int) < sizeof(long) */

	    truncate = FALSE;

	    switch(*fmt) {

		case 'c':
		    c = va_arg(args, int);
		    (*putc)(putc_arg, c);
		    break;

		case 's':
		{
		    register char *p;
		    register char *p2;

		    if (prec == -1)
			prec = 0x7fffffff;	/* MAXINT */

		    p = va_arg(args, char *);

		    if (p == (char *)0)
			p = "";

		    if (length > 0 && !ladjust) {
			n = 0;
			p2 = p;

			for (; *p != '\0' && n < prec; p++)
			    n++;

			p = p2;

			while (n < length) {
			    (*putc)(putc_arg, ' ');
			    n++;
			}
		    }

		    n = 0;

		    while (*p != '\0') {
			if (++n > prec)
			    break;

			(*putc)(putc_arg, *p++);
		    }

		    if (n < length && ladjust) {
			while (n < length) {
			    (*putc)(putc_arg, ' ');
			    n++;
			}
		    }

		    break;
		}

		case 'o':
 		    truncate = _doprnt_truncates;
		case 'O':
		    base = 8;
		    goto print_unsigned;

		case 'd':
 		    truncate = _doprnt_truncates;
		case 'D':
		    base = 10;
		    goto print_signed;

		case 'u':
 		    truncate = _doprnt_truncates;
		case 'U':
		    base = 10;
		    goto print_unsigned;

		case 'p':
		    padc = '0';
		    length = 8;
		    /* 
		     * We do this instead of just setting altfmt to TRUE
		     * because we want 0 to have a 0x in front, and we want
		     * eight digits after the 0x -- not just 6.
		     */
		    (*putc)(putc_arg, '0');
		    (*putc)(putc_arg, 'x');
		case 'x':
 		    truncate = _doprnt_truncates;
		case 'X':
		    base = 16;
		    goto print_unsigned;

		case 'z':
 		    truncate = _doprnt_truncates;
		case 'Z':
		    base = 16;
		    goto print_signed;

		case 'r':
 		    truncate = _doprnt_truncates;
		case 'R':
		    base = radix;
		    goto print_signed;

		case 'n':
 		    truncate = _doprnt_truncates;
		case 'N':
		    base = radix;
		    goto print_unsigned;

		print_signed:
		    n = va_arg(args, long);
		    if (n >= 0) {
			u = n;
			sign_char = plus_sign;
		    }
		    else {
			u = -n;
			sign_char = '-';
		    }
		    goto print_num;

		print_unsigned:
		    u = va_arg(args, unsigned long);
		    goto print_num;

		print_num:
		{
		    char	buf[MAXBUF];	/* build number here */
		    register char *	p = &buf[MAXBUF-1];
		    char *prefix = 0;

		    if (truncate) u = (long)((int)(u));

		    if (u != 0 && altfmt) {
			if (base == 8)
			    prefix = "0";
			else if (base == 16)
			    prefix = "0x";
		    }

		    do {
				*p-- = digits[u % base];
				u /= base;
		    } while (u != 0);

		    length -= (&buf[MAXBUF-1] - p);
		    if (sign_char)
			length--;
		    if (prefix)
			length -= strlen(prefix);

		    if (padc == ' ' && !ladjust) {
			/* blank padding goes before prefix */
			while (--length >= 0)
			    (*putc)(putc_arg, ' ');
		    }
		    if (sign_char)
			(*putc)(putc_arg, sign_char);
		    if (prefix)
			while (*prefix)
			    (*putc)(putc_arg, *prefix++);
		    if (padc == '0') {
			/* zero padding goes after sign and prefix */
			while (--length >= 0)
			    (*putc)(putc_arg, '0');
		    }
		    while (++p != &buf[MAXBUF])
			(*putc)(putc_arg, *p);

		    if (ladjust) {
			while (--length >= 0)
			    (*putc)(putc_arg, ' ');
		    }
		    break;
		}

		case '\0':
		    fmt--;
		    break;

		default:
		    (*putc)(putc_arg, *fmt);
	    }
	fmt++;
	}
}