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, 471 insertions, 0 deletions

diff --git a/lib/libc/stdio/xprintf_int.c b/lib/libc/stdio/xprintf_int.c
new file mode 100644
index 0000000..641690c
--- /dev/null
+++ b/lib/libc/stdio/xprintf_int.c
@@ -0,0 +1,471 @@
+/*-
+ * 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 <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <limits.h>
+#include <locale.h>
+#include <stdint.h>
+#include <assert.h>
+#include <namespace.h>
+#include <string.h>
+#include <wchar.h>
+#include <un-namespace.h>
+
+#include "printf.h"
+
+/* private stuff -----------------------------------------------------*/
+
+union arg {
+	int			intarg;
+	u_int			uintarg;
+	long			longarg;
+	u_long			ulongarg;
+	intmax_t 		intmaxarg;
+	uintmax_t 		uintmaxarg;
+};
+
+/*
+ * Macros for converting digits to letters and vice versa
+ */
+#define	to_char(n)	((n) + '0')
+
+/* various globals ---------------------------------------------------*/
+
+/*
+ * The size of the buffer we use for integer conversions.
+ * Technically, we would need the most space for base 10
+ * conversions with thousands' grouping characters between
+ * each pair of digits: 60 digits for 128 bit intmax_t.
+ * Use a bit more for better alignment of stuff.
+ */
+#define	BUF	64
+
+/* misc --------------------------------------------------------------*/
+
+/*
+ * Convert an unsigned long to ASCII for printf purposes, returning
+ * a pointer to the first character of the string representation.
+ * Octal numbers can be forced to have a leading zero; hex numbers
+ * use the given digits.
+ */
+static char *
+__ultoa(u_long val, char *endp, int base, const char *xdigs,
+	int needgrp, char thousep, const char *grp)
+{
+	char *cp = endp;
+	long sval;
+	int ndig;
+
+	/*
+	 * Handle the three cases separately, in the hope of getting
+	 * better/faster code.
+	 */
+	switch (base) {
+	case 10:
+		if (val < 10) {	/* many numbers are 1 digit */
+			*--cp = to_char(val);
+			return (cp);
+		}
+		ndig = 0;
+		/*
+		 * On many machines, unsigned arithmetic is harder than
+		 * signed arithmetic, so we do at most one unsigned mod and
+		 * divide; this is sufficient to reduce the range of
+		 * the incoming value to where signed arithmetic works.
+		 */
+		if (val > LONG_MAX) {
+			*--cp = to_char(val % 10);
+			ndig++;
+			sval = val / 10;
+		} else
+			sval = val;
+		do {
+			*--cp = to_char(sval % 10);
+			ndig++;
+			/*
+			 * If (*grp == CHAR_MAX) then no more grouping
+			 * should be performed.
+			 */
+			if (needgrp && ndig == *grp && *grp != CHAR_MAX
+					&& sval > 9) {
+				*--cp = thousep;
+				ndig = 0;
+				/*
+				 * If (*(grp+1) == '\0') then we have to
+				 * use *grp character (last grouping rule)
+				 * for all next cases
+				 */
+				if (*(grp+1) != '\0')
+					grp++;
+			}
+			sval /= 10;
+		} while (sval != 0);
+		break;
+
+	case 8:
+		do {
+			*--cp = to_char(val & 7);
+			val >>= 3;
+		} while (val);
+		break;
+
+	case 16:
+		do {
+			*--cp = xdigs[val & 15];
+			val >>= 4;
+		} while (val);
+		break;
+
+	default:			/* oops */
+		assert(base == 16);
+	}
+	return (cp);
+}
+
+
+/* Identical to __ultoa, but for intmax_t. */
+static char *
+__ujtoa(uintmax_t val, char *endp, int base, const char *xdigs, 
+	int needgrp, char thousep, const char *grp)
+{
+	char *cp = endp;
+	intmax_t sval;
+	int ndig;
+
+	switch (base) {
+	case 10:
+		if (val < 10) {
+			*--cp = to_char(val % 10);
+			return (cp);
+		}
+		ndig = 0;
+		if (val > INTMAX_MAX) {
+			*--cp = to_char(val % 10);
+			ndig++;
+			sval = val / 10;
+		} else
+			sval = val;
+		do {
+			*--cp = to_char(sval % 10);
+			ndig++;
+			/*
+			 * If (*grp == CHAR_MAX) then no more grouping
+			 * should be performed.
+			 */
+			if (needgrp && *grp != CHAR_MAX && ndig == *grp
+					&& sval > 9) {
+				*--cp = thousep;
+				ndig = 0;
+				/*
+				 * If (*(grp+1) == '\0') then we have to
+				 * use *grp character (last grouping rule)
+				 * for all next cases
+				 */
+				if (*(grp+1) != '\0')
+					grp++;
+			}
+			sval /= 10;
+		} while (sval != 0);
+		break;
+
+	case 8:
+		do {
+			*--cp = to_char(val & 7);
+			val >>= 3;
+		} while (val);
+		break;
+
+	case 16:
+		do {
+			*--cp = xdigs[val & 15];
+			val >>= 4;
+		} while (val);
+		break;
+
+	default:
+		abort();
+	}
+	return (cp);
+}
+
+
+/* 'd' ---------------------------------------------------------------*/
+
+int
+__printf_arginfo_int(const struct printf_info *pi, size_t n, int *argt)
+{
+	assert (n > 0);
+	argt[0] = PA_INT;
+	if (pi->is_ptrdiff)
+		argt[0] |= PA_FLAG_PTRDIFF;
+	else if (pi->is_size)
+		argt[0] |= PA_FLAG_SIZE;
+	else if (pi->is_long)
+		argt[0] |= PA_FLAG_LONG;
+	else if (pi->is_intmax)
+		argt[0] |= PA_FLAG_INTMAX;
+	else if (pi->is_quad)
+		argt[0] |= PA_FLAG_QUAD;
+	else if (pi->is_long_double)
+		argt[0] |= PA_FLAG_LONG_LONG;
+	else if (pi->is_short)
+		argt[0] |= PA_FLAG_SHORT;
+	else if (pi->is_char)
+		argt[0] = PA_CHAR;
+	return (1);
+}
+
+int
+__printf_render_int(struct __printf_io *io, const struct printf_info *pi, const void *const *arg)
+{
+	const union arg *argp;
+	char buf[BUF];
+	char *p, *pe;
+	char ns, l;
+	int rdx, sign, zext, ngrp;
+	const char *nalt, *digit;
+	char thousands_sep;	/* locale specific thousands separator */
+	const char *grouping;	/* locale specific numeric grouping rules */
+	uintmax_t uu;
+	int ret;
+
+	ret = 0;
+	nalt = NULL;
+	digit = __lowercase_hex;
+	ns = '\0';
+	pe = buf + sizeof buf - 1;
+
+	if (pi->group) {
+		thousands_sep = *(localeconv()->thousands_sep);
+		grouping = localeconv()->grouping;
+		ngrp = 1;
+	} else {
+		thousands_sep = 0;
+		grouping = NULL;
+		ngrp = 0;
+	}
+
+	switch(pi->spec) {
+	case 'd':
+	case 'i':
+		rdx = 10;
+		sign = 1;
+		break;
+	case 'X':
+		digit = __uppercase_hex;
+		/*FALLTHOUGH*/
+	case 'x':
+		rdx = 16;
+		sign = 0;
+		break;
+	case 'u':
+	case 'U':
+		rdx = 10;
+		sign = 0;
+		break;
+	case 'o':
+	case 'O':
+		rdx = 8;
+		sign = 0;
+		break;
+	default:
+		fprintf(stderr, "pi->spec = '%c'\n", pi->spec);
+		assert(1 == 0);
+	}
+	argp = arg[0];
+
+	if (sign)
+		ns = pi->showsign;
+
+	if (pi->is_long_double || pi->is_quad || pi->is_intmax ||
+	    pi->is_size || pi->is_ptrdiff) {
+		if (sign && argp->intmaxarg < 0) {
+			uu = -argp->intmaxarg;
+			ns = '-';
+		} else
+			uu = argp->uintmaxarg;
+	} else if (pi->is_long) {
+		if (sign && argp->longarg < 0) {
+			uu = (u_long)-argp->longarg;
+			ns = '-';
+		} else 
+			uu = argp->ulongarg;
+	} else if (pi->is_short) {
+		if (sign && (short)argp->intarg < 0) {
+			uu = -(short)argp->intarg;
+			ns = '-';
+		} else 
+			uu = (unsigned short)argp->uintarg;
+	} else if (pi->is_char) {
+		if (sign && (char)argp->intarg < 0) {
+			uu = -(char)argp->intarg;
+			ns = '-';
+		} else 
+			uu = (unsigned char)argp->uintarg;
+	} else {
+		if (sign && argp->intarg < 0) {
+			uu = (unsigned)-argp->intarg;
+			ns = '-';
+		} else
+			uu = argp->uintarg;
+	}
+	if (uu <= ULONG_MAX)
+		p = __ultoa(uu, pe, rdx, digit, ngrp, thousands_sep, grouping);
+	else
+		p = __ujtoa(uu, pe, rdx, digit, ngrp, thousands_sep, grouping);
+
+	l = 0;
+	if (uu == 0) {
+		/*-
+		 * ``The result of converting a zero value with an
+		 * explicit precision of zero is no characters.''
+		 *      -- ANSI X3J11
+		 *
+		 * ``The C Standard is clear enough as is.  The call
+		 * printf("%#.0o", 0) should print 0.''
+		 *      -- Defect Report #151
+		 */
+			;
+		if (pi->prec == 0 && !(pi->alt && rdx == 8))
+			p = pe;
+	} else if (pi->alt) {
+		if (rdx == 8) 
+			*--p = '0';
+		if (rdx == 16) {
+			if (pi->spec == 'x')
+				nalt = "0x";
+			else
+				nalt = "0X";
+			l += 2;
+		}
+	}
+	l += pe - p;
+	if (ns)
+		l++;
+
+	/*-
+	 * ``... diouXx conversions ... if a precision is
+	 * specified, the 0 flag will be ignored.''
+	 *      -- ANSI X3J11
+	 */
+	if (pi->prec > (pe - p))
+		zext = pi->prec - (pe - p);
+	else if (pi->prec != -1)
+		zext = 0;
+	else if (pi->pad == '0' && pi->width > l && !pi->left)
+		zext = pi->width - l;
+	else
+		zext = 0;
+
+	l += zext;
+
+	while (zext > 0 && p > buf) {
+		*--p = '0';
+		zext--;
+	}
+
+	if (l < BUF) {
+		if (ns) {
+			*--p = ns;
+		} else if (nalt != NULL) {
+			*--p = nalt[1];
+			*--p = nalt[0];
+		}
+		if (pi->width > (pe - p) && !pi->left) {
+			l = pi->width - (pe - p);
+			while (l > 0 && p > buf) {
+				*--p = ' ';
+				l--;
+			}
+			if (l)
+				ret += __printf_pad(io, l, 0);
+		}
+	} else {
+		if (!pi->left && pi->width > l)
+			ret += __printf_pad(io, pi->width - l, 0);
+		if (ns != '\0')
+			ret += __printf_puts(io, &ns, 1);
+		else if (nalt != NULL)
+			ret += __printf_puts(io, nalt, 2);
+		if (zext > 0)
+			ret += __printf_pad(io, zext, 1);
+	}
+	
+	ret += __printf_puts(io, p, pe - p);
+	if (pi->width > ret && pi->left) 
+		ret += __printf_pad(io, pi->width - ret, 0);
+	__printf_flush(io);
+	return (ret);
+}
+
+/* 'p' ---------------------------------------------------------------*/
+
+int
+__printf_arginfo_ptr(const struct printf_info *pi __unused, size_t n, int *argt)
+{
+
+	assert (n > 0);
+	argt[0] = PA_POINTER;
+	return (1);
+}
+
+int
+__printf_render_ptr(struct __printf_io *io, const struct printf_info *pi, const void *const *arg)
+{
+	struct printf_info p2;
+	uintmax_t u;
+	const void *p;
+
+	/*-
+	 * ``The argument shall be a pointer to void.  The
+	 * value of the pointer is converted to a sequence
+	 * of printable characters, in an implementation-
+	 * defined manner.''
+	 *      -- ANSI X3J11
+	 */
+	u = (uintmax_t)(uintptr_t) *((void **)arg[0]);
+	p2 = *pi;
+
+	p2.spec = 'x';
+	p2.alt = 1;
+	p2.is_long_double = 1;
+	p = &u;
+	return (__printf_render_int(io, &p2, &p));
+}