Convert the insidious macros that handle printf()'s buffering into

slightly less evil inline functions, and move the buffering state into
a struct. This will make it possible for helper routines to produce
output for printf() directly, making it possible to untangle the code
somewhat.

In wprintf(), use the same buffering mechanism to reduce diffs to
printf(). This has the side-effect of causing wprintf() to catch write
errors that it previously ignored.

3 files changed, 204 insertions, 86 deletions

diff --git a/lib/libc/stdio/printfcommon.h b/lib/libc/stdio/printfcommon.h
new file mode 100644
index 0000000..7bc357a
--- /dev/null
+++ b/lib/libc/stdio/printfcommon.h
@@ -0,0 +1,130 @@
+/*-
+ * 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.
+ * 4. 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.
+ *
+ * $FreeBSD$
+ */
+
+/*
+ * This file defines common routines used by both printf and wprintf.
+ * You must define CHAR to either char or wchar_t prior to including this.
+ */
+
+#define NIOV 8
+struct io_state {
+	FILE *fp;
+	struct __suio uio;	/* output information: summary */
+	struct __siov iov[NIOV];/* ... and individual io vectors */
+	struct __siov *iovp;	/* pointer to next free slot in iov */
+};
+
+static inline void
+io_init(struct io_state *iop, FILE *fp)
+{
+
+	iop->uio.uio_iov = iop->iovp = iop->iov;
+	iop->uio.uio_resid = 0;
+	iop->uio.uio_iovcnt = 0;
+	iop->fp = fp;
+}
+
+/*
+ * WARNING: The buffer passed to io_print() is not copied immediately; it must
+ * remain valid until io_flush() is called.
+ */
+static inline int
+io_print(struct io_state *iop, const CHAR * __restrict ptr, int len)
+{
+
+	iop->iovp->iov_base = (char *)ptr;
+	iop->iovp->iov_len = len;
+	iop->uio.uio_resid += len;
+	iop->iovp++;
+	if (++iop->uio.uio_iovcnt >= NIOV) {
+		iop->iovp = iop->iov;
+		return (__sprint(iop->fp, &iop->uio));
+	}
+	return (0);
+}
+
+/*
+ * 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'};
+
+/*
+ * Pad with blanks or zeroes. 'with' should point to either the blanks array
+ * or the zeroes array.
+ */
+static inline int
+io_pad(struct io_state *iop, int howmany, const CHAR * __restrict with)
+{
+
+	while (howmany > PADSIZE) {
+		if (io_print(iop, with, PADSIZE))
+			return (-1);
+		howmany -= PADSIZE;
+	}
+	if (howmany > 0 && io_print(iop, with, howmany))
+		return (-1);
+	return (0);
+}
+
+/*
+ * Print exactly len characters of the string spanning p to ep, truncating
+ * or padding with 'with' as necessary.
+ */
+static inline int
+io_printandpad(struct io_state *iop, const CHAR *p, const CHAR *ep,
+	       int len, const CHAR * __restrict with)
+{
+	int p_len;
+
+	p_len = ep - p;
+	if (p_len > len)
+		p_len = len;
+	if (p_len > 0 && io_print(iop, p, p_len))
+		return (-1);
+	return (io_pad(iop, len - (p_len > 0 ? p_len : 0), with));
+}
+
+static inline int
+io_flush(struct io_state *iop)
+{
+
+	iop->iovp = iop->iov;
+	return (__sprint(iop->fp, &iop->uio));
+}
diff --git a/lib/libc/stdio/vfprintf.c b/lib/libc/stdio/vfprintf.c
index dab331d..69235da 100644
--- a/lib/libc/stdio/vfprintf.c
+++ b/lib/libc/stdio/vfprintf.c
@@ -72,6 +72,9 @@ static char	*__ultoa(u_long, char *, int, int, const char *, int, char,
 		    const char *);
 static char	*__wcsconv(wchar_t *, int);
 
+#define	CHAR	char
+#include "printfcommon.h"
+
 /*
  * Flush out all the vectors defined by the given uio,
  * then reset it so that it can be reused.
@@ -388,7 +391,6 @@ __vfprintf(FILE *fp, const char *fmt0, va_list ap)
 	int ch;			/* character from fmt */
 	int n, n2;		/* handy integer (short term usage) */
 	char *cp;		/* handy char pointer (short term usage) */
-	struct __siov *iovp;	/* for PRINT macro */
 	int flags;		/* flags as above */
 	int ret;		/* return value accumulator */
 	int width;		/* width from format (%8d), or 0 */
@@ -396,6 +398,7 @@ __vfprintf(FILE *fp, const char *fmt0, va_list ap)
 	char sign;		/* sign prefix (' ', '+', '-', or \0) */
 	char thousands_sep;	/* locale specific thousands separator */
 	const char *grouping;	/* locale specific numeric grouping rules */
+
 #ifndef NO_FLOATING_POINT
 	/*
 	 * We can decompose the printed representation of floating
@@ -436,9 +439,7 @@ __vfprintf(FILE *fp, const char *fmt0, va_list ap)
 	int size;		/* size of converted field or string */
 	int prsize;             /* max size of printed field */
 	const char *xdigs;     	/* digits for %[xX] conversion */
-#define NIOV 8
-	struct __suio uio;	/* output information: summary */
-	struct __siov iov[NIOV];/* ... and individual io vectors */
+	struct io_state io;	/* I/O buffering state */
 	char buf[BUF];		/* buffer with space for digits of uintmax_t */
 	char ox[2];		/* space for 0x; ox[1] is either x, X, or \0 */
 	union arg *argtable;    /* args, built due to positional arg */
@@ -447,56 +448,25 @@ __vfprintf(FILE *fp, const char *fmt0, va_list ap)
 	va_list orgap;          /* original argument pointer */
 	char *convbuf;		/* wide to multibyte conversion result */
 
-	/*
-	 * 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 char blanks[PADSIZE] =
-	 {' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' '};
-	static char zeroes[PADSIZE] =
-	 {'0','0','0','0','0','0','0','0','0','0','0','0','0','0','0','0'};
-
 	static const char xdigs_lower[16] = "0123456789abcdef";
 	static const char xdigs_upper[16] = "0123456789ABCDEF";
 
-	/*
-	 * BEWARE, these `goto error' on error, and PAD uses `n'.
-	 */
+	/* BEWARE, these `goto error' on error. */
 #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; \
-	} \
+	if (io_print(&io, (ptr), (len)))	\
+		goto error; \
 }
 #define	PAD(howmany, with) { \
-	if ((n = (howmany)) > 0) { \
-		while (n > PADSIZE) { \
-			PRINT(with, PADSIZE); \
-			n -= PADSIZE; \
-		} \
-		PRINT(with, n); \
-	} \
+	if (io_pad(&io, (howmany), (with))) \
+		goto error; \
+}
+#define	PRINTANDPAD(p, ep, len, with) {	\
+	if (io_printandpad(&io, (p), (ep), (len), (with))) \
+		goto error; \
 }
-#define	PRINTANDPAD(p, ep, len, with) do {	\
-	n2 = (ep) - (p);       			\
-	if (n2 > (len))				\
-		n2 = (len);			\
-	if (n2 > 0)				\
-		PRINT((p), n2);			\
-	PAD((len) - (n2 > 0 ? n2 : 0), (with));	\
-} while(0)
 #define	FLUSH() { \
-	if (uio.uio_resid && __sprint(fp, &uio)) \
+	if (io_flush(&io)) \
 		goto error; \
-	uio.uio_iovcnt = 0; \
-	iovp = iov; \
 }
 
 	/*
@@ -583,9 +553,7 @@ __vfprintf(FILE *fp, const char *fmt0, va_list ap)
 	argtable = NULL;
 	nextarg = 1;
 	va_copy(orgap, ap);
-	uio.uio_iov = iovp = iov;
-	uio.uio_resid = 0;
-	uio.uio_iovcnt = 0;
+	io_init(&io, fp);
 	ret = 0;
 #ifndef NO_FLOATING_POINT
 	dtoaresult = NULL;
diff --git a/lib/libc/stdio/vfwprintf.c b/lib/libc/stdio/vfwprintf.c
index 9f06f1b..aa2fdc8 100644
--- a/lib/libc/stdio/vfwprintf.c
+++ b/lib/libc/stdio/vfwprintf.c
@@ -66,6 +66,7 @@ __FBSDID("$FreeBSD$");
 #include "fvwrite.h"
 #include "printflocal.h"
 
+static int	__sprint(FILE *, struct __suio *);
 static int	__sbprintf(FILE *, const wchar_t *, va_list);
 static wint_t	__xfputwc(wchar_t, FILE *);
 static wchar_t	*__ujtoa(uintmax_t, wchar_t *, int, int, const char *, int,
@@ -74,6 +75,37 @@ static wchar_t	*__ultoa(u_long, wchar_t *, int, int, const char *, int,
 		    char, const char *);
 static wchar_t	*__mbsconv(char *, int);
 
+#define	CHAR	wchar_t
+#include "printfcommon.h"
+
+/*
+ * Flush out all the vectors defined by the given uio,
+ * then reset it so that it can be reused.
+ *
+ * XXX The fact that we do this a character at a time and convert to a
+ * multibyte character sequence even if the destination is a wide
+ * string eclipses the benefits of buffering.
+ */
+static int
+__sprint(FILE *fp, struct __suio *uio)
+{
+	struct __siov *iov;
+	wchar_t *p;
+	int i, len;
+
+	iov = uio->uio_iov;
+	for (; uio->uio_resid != 0; uio->uio_resid -= len, iov++) {
+		p = (wchar_t *)iov->iov_base;
+		len = iov->iov_len;
+		for (i = 0; i < len; i++) {
+			if (__xfputwc(p[i], fp) == WEOF)
+				return (-1);
+		}
+	}
+	uio->uio_iovcnt = 0;
+	return (0);
+}
+
 /*
  * Helper function for `fprintf to unbuffered unix file': creates a
  * temporary buffer.  We only work on write-only files; this avoids
@@ -414,14 +446,14 @@ __vfwprintf(FILE *fp, const wchar_t *fmt0, va_list ap)
 {
 	wchar_t *fmt;		/* format string */
 	wchar_t ch;		/* character from fmt */
-	int n, n2, n3;		/* handy integer (short term usage) */
+	int n, n2;		/* handy integer (short term usage) */
 	wchar_t *cp;		/* handy char pointer (short term usage) */
 	int flags;		/* flags as above */
 	int ret;		/* return value accumulator */
 	int width;		/* width from format (%8d), or 0 */
 	int prec;		/* precision from format; <0 for N/A */
 	wchar_t sign;		/* sign prefix (' ', '+', '-', or \0) */
-	char thousands_sep;	/* locale specific thousands separator */
+	wchar_t thousands_sep;	/* locale specific thousands separator */
 	const char *grouping;	/* locale specific numeric grouping rules */
 #ifndef NO_FLOATING_POINT
 	/*
@@ -463,6 +495,7 @@ __vfwprintf(FILE *fp, const wchar_t *fmt0, va_list ap)
 	int size;		/* size of converted field or string */
 	int prsize;             /* max size of printed field */
 	const char *xdigs;	/* digits for [xX] conversion */
+	struct io_state io;	/* I/O buffering state */
 	wchar_t buf[BUF];	/* buffer with space for digits of uintmax_t */
 	wchar_t ox[2];		/* space for 0x hex-prefix */
 	union arg *argtable;	/* args, built due to positional arg */
@@ -471,45 +504,26 @@ __vfwprintf(FILE *fp, const wchar_t *fmt0, va_list ap)
 	va_list orgap;		/* original argument pointer */
 	wchar_t *convbuf;	/* multibyte to wide conversion result */
 
-	/*
-	 * 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 wchar_t blanks[PADSIZE] =
-	 {' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' '};
-	static wchar_t zeroes[PADSIZE] =
-	 {'0','0','0','0','0','0','0','0','0','0','0','0','0','0','0','0'};
-
 	static const char xdigs_lower[16] = "0123456789abcdef";
 	static const char xdigs_upper[16] = "0123456789ABCDEF";
 
-	/*
-	 * BEWARE, these `goto error' on error, PRINT uses `n2' and
-	 * PAD uses `n'.
-	 */
+	/* BEWARE, these `goto error' on error. */
 #define	PRINT(ptr, len)	do {			\
-	for (n3 = 0; n3 < (len); n3++)		\
-		__xfputwc((ptr)[n3], fp);	\
+	if (io_print(&io, (ptr), (len)))	\
+		goto error; \
 } while (0)
-#define	PAD(howmany, with)	do {		\
-	if ((n = (howmany)) > 0) {		\
-		while (n > PADSIZE) {		\
-			PRINT(with, PADSIZE);	\
-			n -= PADSIZE;		\
-		}				\
-		PRINT(with, n);			\
-	}					\
-} while (0)
-#define	PRINTANDPAD(p, ep, len, with) do {	\
-	n2 = (ep) - (p);       			\
-	if (n2 > (len))				\
-		n2 = (len);			\
-	if (n2 > 0)				\
-		PRINT((p), n2);			\
-	PAD((len) - (n2 > 0 ? n2 : 0), (with));	\
-} while(0)
+#define	PAD(howmany, with) { \
+	if (io_pad(&io, (howmany), (with))) \
+		goto error; \
+}
+#define	PRINTANDPAD(p, ep, len, with) {	\
+	if (io_printandpad(&io, (p), (ep), (len), (with))) \
+		goto error; \
+}
+#define	FLUSH() { \
+	if (io_flush(&io)) \
+		goto error; \
+}
 
 	/*
 	 * Get the argument indexed by nextarg.   If the argument table is
@@ -591,6 +605,7 @@ __vfwprintf(FILE *fp, const wchar_t *fmt0, va_list ap)
 	argtable = NULL;
 	nextarg = 1;
 	va_copy(orgap, ap);
+	io_init(&io, fp);
 	ret = 0;
 #ifndef NO_FLOATING_POINT
 	decimal_point = localeconv()->decimal_point;
@@ -1120,8 +1135,10 @@ number:			if ((dprec = prec) >= 0)
 			if (!expchar) {	/* %[fF] or sufficiently short %[gG] */
 				if (expt <= 0) {
 					PRINT(zeroes, 1);
-					if (prec || flags & ALT)
-						PRINT(decimal_point, 1);
+					if (prec || flags & ALT) {
+						buf[0] = *decimal_point;
+						PRINT(buf, 1);
+					}
 					PAD(-expt, zeroes);
 					/* already handled initial 0's */
 					prec += expt;
@@ -1173,8 +1190,11 @@ number:			if ((dprec = prec) >= 0)
 
 		/* finally, adjust ret */
 		ret += prsize;
+
+		FLUSH();	/* copy out the I/O vectors */
 	}
 done:
+	FLUSH();
 error:
 	va_end(orgap);
 	if (convbuf != NULL)