Add an extensible version of our *printf(3) implementation to libc

on probationary terms:  it may go away again if it transpires it is
a bad idea.

This extensible printf version will only be used if either
    environment variable USE_XPRINTF is defined
or
    one of the extension functions are called.
or
    the global variable __use_xprintf is set greater than zero.

In all other cases our traditional printf implementation will
be used.

The extensible version is slower than the default printf, mostly
because less opportunity for combining I/O operation exists when
faced with extensions.  The default printf on the other hand
is a bad case of spaghetti code.

The extension API has a GLIBC compatible part and a FreeBSD version
of same.  The FreeBSD version exists because the GLIBC version may
run afoul of our FILE * locking in multithreaded programs and it
even further eliminate the opportunities for combining I/O operations.

Include three demo extensions which can be enabled if desired: time
(%T), hexdump (%H) and strvis (%V).

%T can format time_t (%T), struct timeval (%lT) and struct timespec (%llT)
   in one of two human readable duration formats:
	"%.3llT" -> "20349.245"
	"%#.3llT" -> "5h39m9.245"

%H will hexdump a sequence of bytes and takes a pointer and a length
   argument.  The width specifies number of bytes per line.
	"%4H" -> "65 72 20 65"
	"%+4H" -> "0000 65 72 20 65"
	"%#4H" -> "65 72 20 65  |er e|"
	"%+#4H" -> "0000 65 72 20 65  |er e|"

%V will dump a string in strvis format.
	"%V" -> "Hello\tWor\377ld"	(C-style)
	"%0V" -> "Hello\011Wor\377ld"	(octal)
	"%+V" -> "Hello%09Wor%FFld"	(http-style)

Tests, comments, bugreports etc are most welcome.

1 files changed, 674 insertions, 0 deletions

diff --git a/lib/libc/stdio/xprintf.c b/lib/libc/stdio/xprintf.c
new file mode 100644
index 0000000..3b27782
--- /dev/null
+++ b/lib/libc/stdio/xprintf.c
@@ -0,0 +1,674 @@
+/*-
+ * Copyright (c) 2005 Poul-Henning Kamp
+ * Copyright (c) 1990, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Chris Torek.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#include <namespace.h>
+#include <err.h>
+#include <sys/types.h>
+#include <stdio.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <locale.h>
+#include <stdint.h>
+#include <assert.h>
+#include <stdarg.h>
+#include <namespace.h>
+#include <string.h>
+#include <wchar.h>
+#include <un-namespace.h>
+
+#include "printf.h"
+#include "fvwrite.h"
+
+int __use_xprintf = -1;
+
+/* private stuff -----------------------------------------------------*/
+
+union arg {
+	int			intarg;
+	long			longarg;
+	intmax_t 		intmaxarg;
+#ifndef NO_FLOATING_POINT
+	double			doublearg;
+	long double 		longdoublearg;
+#endif
+	wint_t			wintarg;
+	char			*pchararg;
+	wchar_t			*pwchararg;
+	void			*pvoidarg;
+};
+
+/*
+ * Macros for converting digits to letters and vice versa
+ */
+#define	to_digit(c)	((c) - '0')
+#define is_digit(c)	(((unsigned)to_digit(c)) <= 9)
+
+/* various globals ---------------------------------------------------*/
+
+const char __lowercase_hex[17] = "0123456789abcdef?";	/*lint !e784 */
+const char __uppercase_hex[17] = "0123456789ABCDEF?";	/*lint !e784 */
+
+#define PADSIZE 16
+static char blanks[PADSIZE] =
+	 {' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' '};
+static char zeroes[PADSIZE] =
+	 {'0','0','0','0','0','0','0','0','0','0','0','0','0','0','0','0'};
+
+/* printing and padding functions ------------------------------------*/
+
+#define NIOV 8
+
+struct __printf_io {
+	FILE		*fp;
+	struct __suio	uio;
+	struct __siov	iov[NIOV];
+	struct __siov	*iovp;
+};
+
+static void
+__printf_init(struct __printf_io *io)
+{
+
+	io->uio.uio_iov = io->iovp = &io->iov[0];
+	io->uio.uio_resid = 0;
+	io->uio.uio_iovcnt = 0;
+}
+
+void
+__printf_flush(struct __printf_io *io)
+{
+
+	__sfvwrite(io->fp, &io->uio);
+	__printf_init(io);
+}
+
+int
+__printf_puts(struct __printf_io *io, const void *ptr, int len)
+{
+
+
+	if (io->fp->_flags & __SERR)
+		return (0);
+	if (len == 0)
+		return (0);
+	io->iovp->iov_base = __DECONST(void *, ptr);
+	io->iovp->iov_len = len;
+	io->uio.uio_resid += len;
+	io->iovp++;
+	io->uio.uio_iovcnt++;
+	if (io->uio.uio_iovcnt >= NIOV)
+		__printf_flush(io);
+	return (len);
+}
+
+int
+__printf_pad(struct __printf_io *io, int howmany, int zero)
+{
+	int n;
+	const char *with;
+	int ret = 0;
+
+	if (zero)
+		with = zeroes;
+	else
+		with = blanks;
+
+	if ((n = (howmany)) > 0) {
+		while (n > PADSIZE) { 
+			ret += __printf_puts(io, with, PADSIZE);
+			n -= PADSIZE;
+		}
+		ret += __printf_puts(io, with, n);
+	}
+	return (ret);
+}
+
+int
+__printf_out(struct __printf_io *io, const struct printf_info *pi, const void *ptr, int len)
+{
+	int ret = 0;
+
+	if ((!pi->left) && pi->width > len)
+		ret += __printf_pad(io, pi->width - len, pi->pad == '0');
+	ret += __printf_puts(io, ptr, len);
+	if (pi->left && pi->width > len)
+		ret += __printf_pad(io, pi->width - len, pi->pad == '0');
+	return (ret);
+}
+
+
+/* percent handling  -------------------------------------------------*/
+
+static int
+__printf_arginfo_pct(const struct printf_info *pi __unused, size_t n __unused, int *argt __unused)
+{
+
+	return (0);
+}
+
+static int
+__printf_render_pct(struct __printf_io *io, const struct printf_info *pi __unused, const void *const *arg __unused)
+{
+
+	return (__printf_puts(io, "%", 1));
+}
+
+/* 'n' ---------------------------------------------------------------*/
+
+static int
+__printf_arginfo_n(const struct printf_info *pi, size_t n, int *argt)
+{
+
+	assert(n >= 1);
+	argt[0] = PA_POINTER;
+	return (1);
+}
+
+/*
+ * This is a printf_render so that all output has been flushed before it
+ * gets called.
+ */
+
+static int
+__printf_render_n(FILE *io __unused, const struct printf_info *pi, const void *const *arg)
+{
+
+	if (pi->is_char)
+		**((signed char **)arg[0]) = (signed char)pi->sofar;
+	else if (pi->is_short)
+		**((short **)arg[0]) = (short)pi->sofar;
+	else if (pi->is_long)
+		**((long **)arg[0]) = pi->sofar;
+	else if (pi->is_long_double)
+		**((long long **)arg[0]) = pi->sofar;
+	else if (pi->is_intmax)
+		**((intmax_t **)arg[0]) = pi->sofar;
+	else if (pi->is_ptrdiff)
+		**((ptrdiff_t **)arg[0]) = pi->sofar;
+	else if (pi->is_quad)
+		**((quad_t **)arg[0]) = pi->sofar;
+	else if (pi->is_size)
+		**((size_t **)arg[0]) = pi->sofar;
+	else
+		**((int **)arg[0]) = pi->sofar;
+
+	return (0);
+}
+
+/* table -------------------------------------------------------------*/
+
+/*lint -esym(785, printf_tbl) */
+static struct {
+	printf_arginfo_function	*arginfo;
+	printf_function		*gnurender;
+	printf_render		*render;
+} printf_tbl[256] = {
+	['%'] = { __printf_arginfo_pct,		NULL,	__printf_render_pct },
+	['A'] = { __printf_arginfo_float,	NULL,	__printf_render_float },
+	['C'] = { __printf_arginfo_chr,		NULL,	__printf_render_chr },
+	['E'] = { __printf_arginfo_float,	NULL,	__printf_render_float },
+	['F'] = { __printf_arginfo_float,	NULL,	__printf_render_float },
+	['G'] = { __printf_arginfo_float,	NULL,	__printf_render_float },
+	['S'] = { __printf_arginfo_str,		NULL,	__printf_render_str },
+	['X'] = { __printf_arginfo_int,		NULL,	__printf_render_int },
+	['a'] = { __printf_arginfo_float,	NULL,	__printf_render_float },
+	['c'] = { __printf_arginfo_chr,		NULL,	__printf_render_chr },
+	['d'] = { __printf_arginfo_int,		NULL,	__printf_render_int },
+	['e'] = { __printf_arginfo_float,	NULL,	__printf_render_float },
+	['f'] = { __printf_arginfo_float,	NULL,	__printf_render_float },
+	['g'] = { __printf_arginfo_float,	NULL,	__printf_render_float },
+	['i'] = { __printf_arginfo_int,		NULL,	__printf_render_int },
+	['n'] = { __printf_arginfo_n,		__printf_render_n, NULL },
+	['o'] = { __printf_arginfo_int,		NULL,	__printf_render_int },
+	['p'] = { __printf_arginfo_ptr,		NULL,	__printf_render_ptr },
+	['q'] = { __printf_arginfo_int,		NULL,	__printf_render_int },
+	['s'] = { __printf_arginfo_str,		NULL,	__printf_render_str },
+	['u'] = { __printf_arginfo_int,		NULL,	__printf_render_int },
+	['x'] = { __printf_arginfo_int,		NULL,	__printf_render_int },
+};
+
+
+static int
+__v2printf(FILE *fp, const char *fmt0, unsigned pct, const va_list ap)
+{
+	struct printf_info	*pi, *pil;
+	const char		*fmt;
+	int			ch;
+	struct printf_info	pia[pct + 10];
+	int			argt[pct + 10];
+	union arg		args[pct + 10];
+	int			nextarg;
+	int			maxarg;
+	int			ret = 0;
+	int			n;
+	struct __printf_io	io;
+
+	__printf_init(&io);
+	io.fp = fp;
+
+	fmt = fmt0;
+	maxarg = 0;
+	nextarg = 1;
+	memset(argt, 0, sizeof argt);
+	for (pi = pia; ; pi++) {
+		memset(pi, 0, sizeof *pi);
+		pil = pi;
+		if (*fmt == '\0')
+			break;
+		pil = pi + 1;
+		pi->prec = -1;
+		pi->pad = ' ';
+		pi->begin = pi->end = fmt;
+		while (*fmt != '\0' && *fmt != '%')
+			pi->end = ++fmt;
+		if (*fmt == '\0') 
+			break;
+		fmt++;
+		for (;;) {
+			pi->spec = *fmt;
+			switch (pi->spec) {
+			case ' ':
+				/*-
+				 * ``If the space and + flags both appear, the space
+				 * flag will be ignored.''
+				 *      -- ANSI X3J11
+				 */
+				if (pi->showsign == 0)
+					pi->showsign = ' ';
+				fmt++;
+				continue;
+			case '#':
+				pi->alt = 1;
+				fmt++;
+				continue;
+			case '.':
+				pi->prec = 0;
+				fmt++;
+				if (*fmt == '*') {
+					fmt++;
+					pi->get_prec = nextarg;
+					argt[nextarg++] = PA_INT;
+					continue;
+				}
+				while (*fmt != '\0' && is_digit(*fmt)) {
+					pi->prec *= 10;
+					pi->prec += to_digit(*fmt);
+					fmt++;
+				}
+				continue;
+			case '-':
+				pi->left = 1;
+				fmt++;
+				continue;
+			case '+':
+				pi->showsign = '+';
+				fmt++;
+				continue;
+			case '*':
+				fmt++;
+				pi->get_width = nextarg;
+				argt[nextarg++] = PA_INT;
+				continue;
+			case '%':
+				fmt++;
+				break;
+			case '\'':
+				pi->group = 1;
+				fmt++;
+				continue;
+			case '0':
+				/*-
+				 * ``Note that 0 is taken as a flag, not as the
+				 * beginning of a field width.''
+				 *      -- ANSI X3J11
+				 */
+				pi->pad = '0';
+				fmt++;
+				continue;
+			case '1': case '2': case '3':
+			case '4': case '5': case '6':
+			case '7': case '8': case '9':
+				n = 0;
+				while (*fmt != '\0' && is_digit(*fmt)) {
+					n *= 10;
+					n += to_digit(*fmt);
+					fmt++;
+				}
+				if (*fmt == '$') {
+					if (nextarg > maxarg)
+						maxarg = nextarg;
+					nextarg = n;
+					fmt++;
+				} else 
+					pi->width = n;
+				continue;
+			case 'D':
+			case 'O':
+			case 'U':
+				pi->spec += ('a' - 'A');
+				pi->is_intmax = 0;
+				if (pi->is_long_double || pi->is_quad) {
+					pi->is_long = 0;
+					pi->is_long_double = 1;
+				} else {
+					pi->is_long = 1;
+					pi->is_long_double = 0;
+				}
+				fmt++;
+				break;
+			case 'j':
+				pi->is_intmax = 1;
+				fmt++;
+				continue;
+			case 'q':
+				pi->is_long = 0;
+				pi->is_quad = 1;
+				fmt++;
+				continue;
+			case 'L':
+				pi->is_long_double = 1;
+				fmt++;
+				continue;
+			case 'h':
+				fmt++;
+				if (*fmt == 'h') {
+					fmt++;
+					pi->is_char = 1;
+				} else {
+					pi->is_short = 1;
+				}
+				continue;
+			case 'l':
+				fmt++;
+				if (*fmt == 'l') {
+					fmt++;
+					pi->is_long_double = 1;
+					pi->is_quad = 0;
+				} else {
+					pi->is_quad = 0;
+					pi->is_long = 1;
+				}
+				continue;
+			case 't':
+				pi->is_ptrdiff = 1;
+				fmt++;
+				continue;
+			case 'z':
+				pi->is_size = 1;
+				fmt++;
+				continue;
+			default:
+				fmt++;
+				break;
+			}
+			if (printf_tbl[pi->spec].arginfo == NULL)
+				errx(1, "arginfo[%c] = NULL", pi->spec);
+			ch = printf_tbl[pi->spec].arginfo(
+			    pi, __PRINTFMAXARG, &argt[nextarg]);
+			if (ch > 0)
+				pi->arg[0] = &args[nextarg];
+			if (ch > 1)
+				pi->arg[1] = &args[nextarg + 1];
+			nextarg += ch;
+			break;
+		}
+	}
+	if (nextarg > maxarg)
+		maxarg = nextarg;
+#if 0
+	fprintf(stderr, "fmt0 <%s>\n", fmt0);
+	fprintf(stderr, "pil %p\n", pil);
+#endif
+	for (ch = 1; ch < maxarg; ch++) {
+#if 0
+		fprintf(stderr, "arg %d %x\n", ch, argt[ch]);
+#endif
+		switch(argt[ch]) {
+		case PA_CHAR:
+			args[ch].intarg = (char)va_arg (ap, int);
+			break;
+		case PA_INT:
+			args[ch].intarg = va_arg (ap, int);
+			break;
+		case PA_INT | PA_FLAG_SHORT:
+			args[ch].intarg = (short)va_arg (ap, int);
+			break;
+		case PA_INT | PA_FLAG_LONG:
+			args[ch].longarg = va_arg (ap, long);
+			break;
+		case PA_INT | PA_FLAG_INTMAX:
+			args[ch].intmaxarg = va_arg (ap, intmax_t);
+			break;
+		case PA_INT | PA_FLAG_QUAD:
+			args[ch].intmaxarg = va_arg (ap, quad_t);
+			break;
+		case PA_INT | PA_FLAG_LONG_LONG:
+			args[ch].intmaxarg = va_arg (ap, long long);
+			break;
+		case PA_INT | PA_FLAG_SIZE:
+			args[ch].intmaxarg = va_arg (ap, size_t);
+			break;
+		case PA_INT | PA_FLAG_PTRDIFF:
+			args[ch].intmaxarg = va_arg (ap, ptrdiff_t);
+			break;
+		case PA_WCHAR:
+			args[ch].wintarg = va_arg (ap, wint_t);
+			break;
+		case PA_POINTER:
+			args[ch].pvoidarg = va_arg (ap, void *);
+			break;
+		case PA_STRING:
+			args[ch].pchararg = va_arg (ap, char *);
+			break;
+		case PA_WSTRING:
+			args[ch].pwchararg = va_arg (ap, wchar_t *);
+			break;
+		case PA_DOUBLE:
+			args[ch].doublearg = va_arg (ap, double);
+			break;
+		case PA_DOUBLE | PA_FLAG_LONG_DOUBLE:
+			args[ch].longdoublearg = va_arg (ap, long double);
+			break;
+		default:
+			errx(1, "argtype = %x (fmt = \"%s\")\n",
+			    argt[ch], fmt0);
+		}
+	}
+	for (pi = pia; pi < pil; pi++) {
+#if 0
+		fprintf(stderr, "pi %p", pi);
+		fprintf(stderr, " spec '%c'", pi->spec);
+		fprintf(stderr, " args %d",
+		    ((uintptr_t)pi->arg[0] - (uintptr_t)args) / sizeof args[0]);
+		if (pi->width) fprintf(stderr, " width %d", pi->width);
+		if (pi->pad) fprintf(stderr, " pad 0x%x", pi->pad);
+		if (pi->left) fprintf(stderr, " left");
+		if (pi->showsign) fprintf(stderr, " showsign");
+		if (pi->prec != -1) fprintf(stderr, " prec %d", pi->prec);
+		if (pi->is_char) fprintf(stderr, " char");
+		if (pi->is_short) fprintf(stderr, " short");
+		if (pi->is_long) fprintf(stderr, " long");
+		if (pi->is_long_double) fprintf(stderr, " long_double");
+		fprintf(stderr, "\n");
+		fprintf(stderr, "\t\"%.*s\"\n", pi->end - pi->begin, pi->begin);
+#endif
+		if (pi->get_width) {
+			pi->width = args[pi->get_width].intarg;
+			/*-
+			 * ``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.
+			 */
+			if (pi->width < 0) {
+				pi->left = 1;
+				pi->width = -pi->width;
+			}
+		}
+		if (pi->get_prec) 
+			pi->prec = args[pi->get_prec].intarg;
+		ret += __printf_puts(&io, pi->begin, pi->end - pi->begin);
+		if (printf_tbl[pi->spec].gnurender != NULL) {
+			__printf_flush(&io);
+			pi->sofar = ret;
+			ret += printf_tbl[pi->spec].gnurender(
+			    fp, pi, (const void *)pi->arg);
+		} else if (printf_tbl[pi->spec].render != NULL) {
+			pi->sofar = ret;
+			n = printf_tbl[pi->spec].render(
+			    &io, pi, (const void *)pi->arg);
+			if (n < 0)
+				io.fp->_flags |= __SERR;
+			else
+				ret += n;
+		} else if (pi->begin == pi->end)
+			errx(1, "render[%c] = NULL", *fmt);
+	}
+	__printf_flush(&io);
+	return (ret);
+}
+
+extern int      __fflush(FILE *fp);
+
+/*
+ * Helper function for `fprintf to unbuffered unix file': creates a
+ * temporary buffer.  We only work on write-only files; this avoids
+ * worries about ungetc buffers and so forth.
+ */
+static int
+__v3printf(FILE *fp, const char *fmt, int pct, va_list ap)
+{
+	int ret;
+	FILE fake;
+	unsigned char buf[BUFSIZ];
+
+	/* copy the important variables */
+	fake._flags = fp->_flags & ~__SNBF;
+	fake._file = fp->_file;
+	fake._cookie = fp->_cookie;
+	fake._write = fp->_write;
+	fake._extra = fp->_extra;
+
+	/* set up the buffer */
+	fake._bf._base = fake._p = buf;
+	fake._bf._size = fake._w = sizeof(buf);
+	fake._lbfsize = 0;	/* not actually used, but Just In Case */
+
+	/* do the work, then copy any error status */
+	ret = __v2printf(&fake, fmt, pct, ap);
+	if (ret >= 0 && __fflush(&fake))
+		ret = EOF;
+	if (fake._flags & __SERR)
+		fp->_flags |= __SERR;
+	return (ret);
+}
+
+int
+__xvprintf(FILE *fp, const char *fmt0, va_list ap)
+{
+	unsigned u;
+	const char *p;
+
+	/* Count number of '%' signs handling double '%' signs */
+	for (p = fmt0, u = 0; *p; p++) {
+		if (*p != '%')
+			continue;
+		u++;
+		if (p[1] == '%')
+			p++;
+	}
+
+	/* optimise fprintf(stderr) (and other unbuffered Unix files) */
+	if ((fp->_flags & (__SNBF|__SWR|__SRW)) == (__SNBF|__SWR) &&
+	    fp->_file >= 0)
+		return (__v3printf(fp, fmt0, u, ap));
+	else
+		return (__v2printf(fp, fmt0, u, ap));
+}
+
+/* extending ---------------------------------------------------------*/
+
+int
+register_printf_function(int spec, printf_function *render, printf_arginfo_function *arginfo)
+{
+
+	if (spec > 255 || spec < 0)
+		return (-1);
+	printf_tbl[spec].gnurender = render;
+	printf_tbl[spec].arginfo = arginfo;
+	__use_xprintf = 1;
+	return (0);
+}
+
+int
+register_printf_render(int spec, printf_render *render, printf_arginfo_function *arginfo)
+{
+
+	if (spec > 255 || spec < 0)
+		return (-1);
+	printf_tbl[spec].render = render;
+	printf_tbl[spec].arginfo = arginfo;
+	__use_xprintf = 1;
+	return (0);
+}
+
+int
+register_printf_render_std(const unsigned char *specs)
+{
+
+	for (; *specs != '\0'; specs++) {
+		switch (*specs) {
+		case 'H':
+			register_printf_render(*specs,
+			    __printf_render_hexdump,
+			    __printf_arginfo_hexdump);
+			break;
+		case 'T':
+			register_printf_render(*specs,
+			    __printf_render_time,
+			    __printf_arginfo_time);
+			break;
+		case 'V':
+			register_printf_render(*specs,
+			    __printf_render_vis,
+			    __printf_arginfo_vis);
+			break;
+		default:
+			return (-1);
+		}
+	}
+	return (0);
+}
+