path: root/kern/printf.c

/* 
 * Mach Operating System
 * Copyright (c) 1993 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  Software.Distribution@CS.CMU.EDU
 *  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
 *	%p      pointer address
 *	%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 formats for decoding device registers:
 *
 * printf("reg = %b", regval, "<base><arg>*")
 *
 * where <base> is the output base expressed as a control character:
 * i.e. '\10' gives octal, '\20' gives hex.  Each <arg> is a sequence of
 * characters, the first of which gives the bit number to be inspected
 * (origin 1), and the rest (up to a control character (<= 32)) give the
 * name of the register.  Thus
 *	printf("reg = %b\n", 3, "\10\2BITTWO\1BITONE")
 * would produce
 *	reg = 3<BITTWO,BITONE>
 *
 * If the second character in <arg> is also a control character, it
 * indicates the last bit of a bit field.  In this case, printf will extract
 * bits <1> to <2> and print it.  Characters following the second control
 * character are printed before the bit field.
 *	printf("reg = %b\n", 0xb, "\10\4\3FIELD1=\2BITTWO\1BITONE")
 * would produce
 *	reg = b<FIELD1=2,BITONE>
 */
/*
 * 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)
 */

#include <mach/boolean.h>
#include <kern/lock.h>
#include <kern/strings.h>
#include <stdarg.h>

#define isdigit(d) ((d) >= '0' && (d) <= '9')
#define Ctod(c) ((c) - '0')

#define MAXBUF (sizeof(long int) * 8)		 /* enough for binary */


void printnum(
	register unsigned long	u,
	register int		base,
	void			(*putc)( char, vm_offset_t ),
	vm_offset_t		putc_arg)
{
	char	buf[MAXBUF];	/* build number here */
	register char *	p = &buf[MAXBUF-1];
	static char digs[] = "0123456789abcdef";

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

	while (++p != &buf[MAXBUF])
	    (*putc)(*p, putc_arg);

}

boolean_t	_doprnt_truncates = FALSE;

/* printf could be called at _any_ point during system initialization,
   including before printf_init() gets called from the "normal" place
   in kern/startup.c.  */
boolean_t	_doprnt_lock_initialized = FALSE;
decl_simple_lock_data(,_doprnt_lock)

void printf_init()
{
	if (!_doprnt_lock_initialized)
	{
		_doprnt_lock_initialized = TRUE;
		simple_lock_init(&_doprnt_lock);
	}
}

void _doprnt(
	register const char *fmt,
	va_list		*argp,
					/* character output routine */
 	void		(*putc)( char, vm_offset_t),
	int		radix,		/* default radix - for '%r' */
	vm_offset_t	putc_arg)
{
	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;
	register char	c;

	printf_init();

#if 0
	/* Make sure that we get *some* printout, no matter what */
	simple_lock(&_doprnt_lock);
#else
	{
		register int i = 0;
		while (i < 1*1024*1024) {
			if (simple_lock_try(&_doprnt_lock))
				break;
			i++;
		}
	}
#endif

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

	    fmt++;

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

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

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

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

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

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

	    truncate = FALSE;

	    switch(c) {
		case 'b':
		case 'B':
		{
		    register char *p;
		    boolean_t	  any;
		    register int  i;

		    u = va_arg(*argp, unsigned long);
		    p = va_arg(*argp, char *);
		    base = *p++;
		    printnum(u, base, putc, putc_arg);

		    if (u == 0)
			break;

		    any = FALSE;
		    while (i = *p++) {
			/* NOTE: The '32' here is because ascii space */
			if (*p <= 32) {
			    /*
			     * Bit field
			     */
			    register int j;
			    if (any)
				(*putc)(',', putc_arg);
			    else {
				(*putc)('<', putc_arg);
				any = TRUE;
			    }
			    j = *p++;
			    for (; (c = *p) > 32; p++)
				(*putc)(c, putc_arg);
			    printnum((unsigned)( (u>>(j-1)) & ((2<<(i-j))-1)),
					base, putc, putc_arg);
			}
			else if (u & (1<<(i-1))) {
			    if (any)
				(*putc)(',', putc_arg);
			    else {
				(*putc)('<', putc_arg);
				any = TRUE;
			    }
			    for (; (c = *p) > 32; p++)
				(*putc)(c, putc_arg);
			}
			else {
			    for (; *p > 32; p++)
				continue;
			}
		    }
		    if (any)
			(*putc)('>', putc_arg);
		    break;
		}

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

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

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

		    p = va_arg(*argp, 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)(*p++, putc_arg);
		    }

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

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

		print_num:
		{
		    char	buf[MAXBUF];	/* build number here */
		    register char *	p = &buf[MAXBUF-1];
		    static char digits[] = "0123456789abcdef";
		    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)(sign_char, putc_arg);
		    if (prefix)
			while (*prefix)
			    (*putc)(*prefix++, putc_arg);
		    if (padc == '0') {
			/* zero padding goes after sign and prefix */
			while (--length >= 0)
			    (*putc)('0', putc_arg);
		    }
		    while (++p != &buf[MAXBUF])
			(*putc)(*p, putc_arg);

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

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

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

	simple_unlock(&_doprnt_lock);
}

/*
 * Printing (to console)
 */
extern void	cnputc( char, /*not really*/vm_offset_t);

void vprintf(const char *fmt, va_list listp)
{
	_doprnt(fmt, &listp, cnputc, 16, 0);
}

/*VARARGS1*/
void printf(const char *fmt, ...)
{
	va_list	listp;
	va_start(listp, fmt);
	vprintf(fmt, listp);
	va_end(listp);
}

int	indent = 0;

/*
 * Printing (to console) with indentation.
 */
/*VARARGS1*/
void iprintf(const char *fmt, ...)
{
	va_list	listp;
	register int i;

	for (i = indent; i > 0; ){
	    if (i >= 8) {
		printf("\t");
		i -= 8;
	    }
	    else {
		printf(" ");
		i--;
	    }
	}
	va_start(listp, fmt);
	_doprnt(fmt, &listp, cnputc, 16, 0);
	va_end(listp);
}

/*
 * Printing to generic buffer
 * Returns #bytes printed.
 * Strings are zero-terminated.
 */
static void
sputc(
	char		c,
	vm_offset_t	arg)
{
	register char	**bufp = (char **) arg;
	register char	*p = *bufp;
	*p++ = c;
	*bufp = p;
}

int
sprintf(char *buf, const char *fmt, ...)
{
	va_list	listp;
	char	*start = buf;

	va_start(listp, fmt);
	_doprnt(fmt, &listp, sputc, 16, (vm_offset_t)&buf);
	va_end(listp);

	*buf = 0;
	return (buf - start);
}

struct vsnprintf_cookie
{
  char *buf;
  int index;
  int max_len;
};

static void
snputc(char c, vm_offset_t arg)
{
  struct vsnprintf_cookie *cookie = (void *) arg;

  if (cookie->index < cookie->max_len)
    cookie->buf[cookie->index ++] = c;
}

int
vsnprintf(char *buf, int size, const char *fmt, va_list args)
{
  struct vsnprintf_cookie cookie
    = { .buf = buf, .index = 0, .max_len = size };

  _doprnt (fmt, &args, snputc, 16, (vm_offset_t)&cookie);
  cookie.buf[cookie.index] = '\0';

  return cookie.index;
}


void safe_gets(str, maxlen)
	char *str;
	int  maxlen;
{
	register char *lp;
	register int c;
	char *strmax = str + maxlen - 1; /* allow space for trailing 0 */

	lp = str;
	for (;;) {
		c = cngetc();
		switch (c) {
		case '\n':
		case '\r':
			printf("\n");
			*lp++ = 0;
			return;
			
		case '\b':
		case '#':
		case '\177':
			if (lp > str) {
				printf("\b \b");
				lp--;
			}
			continue;

		case '@':
		case 'u'&037:
			lp = str;
			printf("\n\r");
			continue;

		default:
			if (c >= ' ' && c < '\177') {
				if (lp < strmax) {
					*lp++ = c;
					printf("%c", c);
				}
				else {
					printf("%c", '\007'); /* beep */
				}
			}
		}
	}
}