vfprintf.c

来自「用于嵌入式Linux系统的标准C的库函数」· C语言 代码 · 共 1,722 行 · 第 1/4 页

	enum { OCT, DEC, HEX } base;/* base for [diouxX] conversion */
	int dprec;		/* a copy of prec if [diouxX], 0 otherwise */
	int realsz;		/* field size expanded by dprec */
	int size;		/* size of converted field or string */
	char *xdigs = NULL;	/* digits for [xX] conversion */
#define NIOV 8
	struct __suio uio;	/* output information: summary */
	struct __siov iov[NIOV];/* ... and individual io vectors */
	char buf[BUF];		/* space for %c, %[diouxX], %[eEfgG] */
	char ox[2];		/* space for 0x hex-prefix */
#ifdef MB_CAPABLE
	wchar_t wc;
	mbstate_t state;        /* mbtowc calls from library must not change state */
#endif
	char *malloc_buf = NULL;/* handy pointer for malloced buffers */

	/*
	 * Choose PADSIZE to trade efficiency vs. size.  If larger printf
	 * fields occur frequently, increase PADSIZE and make the initialisers
	 * below longer.
	 */
#define	PADSIZE	16		/* pad chunk size */
	static _CONST char blanks[PADSIZE] =
	 {' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' '};
	static _CONST char zeroes[PADSIZE] =
	 {'0','0','0','0','0','0','0','0','0','0','0','0','0','0','0','0'};

#ifdef MB_CAPABLE
        memset (&state, '\0', sizeof (state));
#endif
	/*
	 * BEWARE, these `goto error' on error, and PAD uses `n'.
	 */
#define	PRINT(ptr, len) { \
	iovp->iov_base = (ptr); \
	iovp->iov_len = (len); \
	uio.uio_resid += (len); \
	iovp++; \
	if (++uio.uio_iovcnt >= NIOV) { \
		if (__sprint(fp, &uio)) \
			goto error; \
		iovp = iov; \
	} \
}
#define	PAD(howmany, with) { \
	if ((n = (howmany)) > 0) { \
		while (n > PADSIZE) { \
			PRINT(with, PADSIZE); \
			n -= PADSIZE; \
		} \
		PRINT(with, n); \
	} \
}
#define	FLUSH() { \
	if (uio.uio_resid && __sprint(fp, &uio)) \
		goto error; \
	uio.uio_iovcnt = 0; \
	iovp = iov; \
}

	/* Macros to support positional arguments */
#ifndef _NO_POS_ARGS
#define GET_ARG(n, ap, type) \
  ( is_pos_arg \
      ? n < numargs \
         ? args[n].val_##type \
         : get_arg (data, n, fmt_anchor, &ap, &numargs, args, arg_type, &saved_fmt)->val_##type \
      : arg_index++ < numargs \
         ? args[n].val_##type \
         : numargs < MAX_POS_ARGS \
           ? args[numargs++].val_##type = va_arg(ap, type) \
           : va_arg(ap, type) \
  )
#else
#define GET_ARG(n, ap, type) (va_arg(ap, type))
#endif
    
	/*
	 * To extend shorts properly, we need both signed and unsigned
	 * argument extraction methods.
	 */
#ifndef _NO_LONGLONG
#define	SARG() \
	(flags&QUADINT ? GET_ARG(N, ap, quad_t) : \
	    flags&LONGINT ? GET_ARG(N, ap, long) : \
	    flags&SHORTINT ? (long)(short)GET_ARG(N, ap, int) : \
	    (long)GET_ARG(N, ap, int))
#define	UARG() \
	(flags&QUADINT ? GET_ARG(N, ap, u_quad_t) : \
	    flags&LONGINT ? GET_ARG(N, ap, u_long) : \
	    flags&SHORTINT ? (u_long)(u_short)GET_ARG(N, ap, int) : \
	    (u_long)GET_ARG(N, ap, u_int))
#else
#define	SARG() \
	(flags&LONGINT ? GET_ARG(N, ap, long) : \
	    flags&SHORTINT ? (long)(short)GET_ARG(N, ap, int) : \
	    (long)GET_ARG(N, ap, int))
#define	UARG() \
	(flags&LONGINT ? GET_ARG(N, ap, u_long) : \
	    flags&SHORTINT ? (u_long)(u_short)GET_ARG(N, ap, int) : \
	    (u_long)GET_ARG(N, ap, u_int))
#endif

	/* sorry, fprintf(read_only_file, "") returns EOF, not 0 */
	if (cantwrite(fp))
		return (EOF);

	/* optimise fprintf(stderr) (and other unbuffered Unix files) */
	if ((fp->_flags & (__SNBF|__SWR|__SRW)) == (__SNBF|__SWR) &&
	    fp->_file >= 0)
		return (__sbprintf(fp, fmt0, ap));

	fmt = (char *)fmt0;
	uio.uio_iov = iovp = iov;
	uio.uio_resid = 0;
	uio.uio_iovcnt = 0;
	ret = 0;
	arg_index = 0;
#ifndef _NO_POS_ARGS
	saved_fmt = NULL;
	arg_type[0] = -1;
	numargs = 0;
	is_pos_arg = 0;
#endif

	/*
	 * Scan the format for conversions (`%' character).
	 */
	for (;;) {
	        cp = fmt;
#ifdef MB_CAPABLE
	        while ((n = _mbtowc_r(data, &wc, fmt, MB_CUR_MAX, &state)) > 0) {
                    if (wc == '%')
                        break;
                    fmt += n;
		}
#else
                while (*fmt != '\0' && *fmt != '%')
                    fmt += 1;
#endif
		if ((m = fmt - cp) != 0) {
			PRINT(cp, m);
			ret += m;
		}
#ifdef MB_CAPABLE
		if (n <= 0)
                    goto done;
#else
                if (*fmt == '\0')
                    goto done;
#endif
		fmt_anchor = fmt;
		fmt++;		/* skip over '%' */

		flags = 0;
		dprec = 0;
		width = 0;
		prec = -1;
		sign = '\0';
		N = arg_index;
#ifndef _NO_POS_ARGS
		is_pos_arg = 0;
#endif

rflag:		ch = *fmt++;
reswitch:	switch (ch) {
		case ' ':
			/*
			 * ``If the space and + flags both appear, the space
			 * flag will be ignored.''
			 *	-- ANSI X3J11
			 */
			if (!sign)
				sign = ' ';
			goto rflag;
		case '#':
			flags |= ALT;
			goto rflag;
		case '*':
			n = N;
#ifndef _NO_POS_ARGS
			/* we must check for positional arg used for dynamic width */
			old_is_pos_arg = is_pos_arg;
			is_pos_arg = 0;
			if (is_digit(*fmt)) {
				char *old_fmt = fmt;

				n = 0;
				ch = *fmt++;
				do {
					n = 10 * n + to_digit(ch);
					ch = *fmt++;
				} while (is_digit(ch));

				if (ch == '$') {
					if (n <= MAX_POS_ARGS) {
						n -= 1;
						is_pos_arg = 1;
					}
					else
						goto error;
				}
				else {
					fmt = old_fmt;
					goto rflag;
				}
			}
#endif /* !_NO_POS_ARGS */

			/*
			 * ``A negative field width argument is taken as a
			 * - flag followed by a positive field width.''
			 *	-- ANSI X3J11
			 * They don't exclude field widths read from args.
			 */
			width = GET_ARG(n, ap, int);
#ifndef _NO_POS_ARGS
			is_pos_arg = old_is_pos_arg;
#endif
			if (width >= 0)
				goto rflag;
			width = -width;
			/* FALLTHROUGH */
		case '-':
			flags |= LADJUST;
			goto rflag;
		case '+':
			sign = '+';
			goto rflag;
		case '.':
			if ((ch = *fmt++) == '*') {
				n = N;
#ifndef _NO_POS_ARGS
				/* we must check for positional arg used for dynamic width */
				old_is_pos_arg = is_pos_arg;
				is_pos_arg = 0;
				if (is_digit(*fmt)) {
					char *old_fmt = fmt;

					n = 0;
					ch = *fmt++;
					do {
						n = 10 * n + to_digit(ch);
						ch = *fmt++;
					} while (is_digit(ch));

					if (ch == '$') {
						if (n <= MAX_POS_ARGS) {
							n -= 1;
							is_pos_arg = 1;
						}
						else
							goto error;
					}
					else {
						fmt = old_fmt;
						goto rflag;
					}
				}
#endif /* !_NO_POS_ARGS */
				prec = GET_ARG(n, ap, int);
#ifndef _NO_POS_ARGS
				is_pos_arg = old_is_pos_arg;
#endif
				if (prec < 0)
					prec = -1;
				goto rflag;
			}
			n = 0;
			while (is_digit(ch)) {
				n = 10 * n + to_digit(ch);
				ch = *fmt++;
			}
			prec = n < 0 ? -1 : n;
			goto reswitch;
		case '0':
			/*
			 * ``Note that 0 is taken as a flag, not as the
			 * beginning of a field width.''
			 *	-- ANSI X3J11
			 */
			flags |= ZEROPAD;
			goto rflag;
		case '1': case '2': case '3': case '4':
		case '5': case '6': case '7': case '8': case '9':
			n = 0;
			do {
				n = 10 * n + to_digit(ch);
				ch = *fmt++;
			} while (is_digit(ch));
#ifndef _NO_POS_ARGS
			if (ch == '$') {
				if (n <= MAX_POS_ARGS) {
					N = n - 1;
					is_pos_arg = 1;
					goto rflag;
				}
				else
					goto error;
			}
#endif /* !_NO_POS_ARGS */
			width = n;
			goto reswitch;
#ifdef FLOATING_POINT
		case 'L':
			flags |= LONGDBL;
			goto rflag;
#endif
		case 'h':
			flags |= SHORTINT;
			goto rflag;
		case 'l':
			if (*fmt == 'l') {
				fmt++;
				flags |= QUADINT;
			} else {
				flags |= LONGINT;
			}
			goto rflag;
		case 'q':
			flags |= QUADINT;
			goto rflag;
		case 'c':
		case 'C':
			cp = buf;
			if (ch == 'C' || (flags & LONGINT)) {
				mbstate_t ps;

				memset((void *)&ps, '\0', sizeof(mbstate_t));
				if ((size = (int)_wcrtomb_r(data, cp, 
				    	       (wchar_t)GET_ARG(N, ap, wint_t), 
					        &ps)) == -1)
					goto error; 
			}
			else {
				*cp = GET_ARG(N, ap, int);
				size = 1;
			}
			sign = '\0';
			break;
		case 'D':
			flags |= LONGINT;
			/*FALLTHROUGH*/
		case 'd':
		case 'i':
			_uquad = SARG();
#ifndef _NO_LONGLONG
			if ((quad_t)_uquad < 0)
#else
			if ((long) _uquad < 0)
#endif
			{

				_uquad = -_uquad;
				sign = '-';
			}
			base = DEC;
			goto number;
#ifdef FLOATING_POINT
		case 'e':
		case 'E':
		case 'f':
		case 'g':
		case 'G':
			if (prec == -1) {
				prec = DEFPREC;
			} else if ((ch == 'g' || ch == 'G') && prec == 0) {
				prec = 1;
			}

#ifdef _NO_LONGDBL
			if (flags & LONGDBL) {
				_fpvalue = (double) GET_ARG(N, ap, _LONG_DOUBLE);
			} else {
				_fpvalue = GET_ARG(N, ap, double);
			}

			/* do this before tricky precision changes */
			if (isinf(_fpvalue)) {
				if (_fpvalue < 0)
					sign = '-';
				cp = "Inf";
				size = 3;
				break;
			}
			if (isnan(_fpvalue)) {
				cp = "NaN";
				size = 3;
				break;
			}

#else /* !_NO_LONGDBL */
			
			if (flags & LONGDBL) {
				_fpvalue = GET_ARG(N, ap, _LONG_DOUBLE);
			} else {
				_fpvalue = (_LONG_DOUBLE)GET_ARG(N, ap, double);
			}

			/* do this before tricky precision changes */
			tmp = _ldcheck (&_fpvalue);
			if (tmp == 2) {
				if (_fpvalue < 0)
					sign = '-';
				cp = "Inf";
				size = 3;
				break;
			}
			if (tmp == 1) {
				cp = "NaN";
				size = 3;
				break;
			}
#endif /* !_NO_LONGDBL */

			flags |= FPT;

			cp = cvt(data, _fpvalue, prec, flags, &softsign,
				&expt, ch, &ndig);

			if (ch == 'g' || ch == 'G') {
				if (expt <= -4 || expt > prec)
					ch = (ch == 'g') ? 'e' : 'E';
				else
					ch = 'g';
			} 
			if (ch <= 'e') {	/* 'e' or 'E' fmt */
				--expt;
				expsize = exponent(expstr, expt, ch);
				size = expsize + ndig;
				if (ndig > 1 || flags & ALT)