Add an open_wmemstream(3) implementation and fix various issues for

fmemopen(3) and open_memstream(3).

With inputs from millert@, stsp@, guenther@, tedu@ and matthew@

3 files changed, 211 insertions, 55 deletions

diff --git a/lib/libc/stdio/fmemopen.c b/lib/libc/stdio/fmemopen.c
index fd76f625b23..8cda0476340 100644
--- a/lib/libc/stdio/fmemopen.c
+++ b/lib/libc/stdio/fmemopen.c
@@ -1,4 +1,5 @@
-/*	$OpenBSD: fmemopen.c,v 1.1 2013/01/01 17:41:13 mpi Exp $	*/
+/*	$OpenBSD: fmemopen.c,v 1.2 2013/03/27 15:06:25 mpi Exp $	*/
+
 /*
  * Copyright (c) 2011 Martin Pieuchot <mpi@openbsd.org>
  * Copyright (c) 2009 Ted Unangst
@@ -20,6 +21,7 @@
 #include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include "local.h"
 
 struct state {
@@ -27,6 +29,7 @@ struct state {
 	size_t		 pos;		/* current position */
 	size_t		 size;		/* allocated size */
 	size_t		 len;		/* length of the data */
+	int		 update;	/* open for update */
 };
 
 static int
@@ -55,44 +58,40 @@ fmemopen_write(void *v, const char *b, int l)
 	if (st->pos >= st->len) {
 		st->len = st->pos;
 
-		if (st->len == st->size)
-			st->string[st->len - 1] = '\0';
-		else
+		if (st->len < st->size)
 			st->string[st->len] = '\0';
+		else if (!st->update)
+			st->string[st->size - 1] = '\0';
 	}
 
 	return (i);
 }
 
 static fpos_t
-fmemopen_seek(void *v, fpos_t pos, int whence)
+fmemopen_seek(void *v, fpos_t off, int whence)
 {
 	struct state	*st = v;
+	ssize_t		 base = 0;
 
 	switch (whence) {
 	case SEEK_SET:
 		break;
 	case SEEK_CUR:
-		pos += st->pos;
+		base = st->pos;
 		break;
 	case SEEK_END:
-		/*
-		 * XXX The standard is not clear about where to seek
-		 * from the end of the data or the end of the buffer.
-		 */
-		pos += st->len;
+		base = st->len;
 		break;
-	default:
-		errno = EINVAL;
-		return (-1);
 	}
 
-	if (pos < 0 || pos > st->size)
+	if (off > st->size - base || off < -base) {
+		errno = EOVERFLOW;
 		return (-1);
+	}
 
-	st->pos = pos;
+	st->pos = base + off;
 
-	return (pos);
+	return (st->pos);
 }
 
 static int
@@ -145,8 +144,9 @@ fmemopen(void *buf, size_t size, const char *mode)
 	}
 
 	st->pos = 0;
-	st->len = 0;
+	st->len = (oflags & O_WRONLY) ? 0 : size;
 	st->size = size;
+	st->update = oflags & O_RDWR;
 
 	if (buf == NULL) {
 		if ((st->string = malloc(size)) == NULL) {
@@ -158,9 +158,6 @@ fmemopen(void *buf, size_t size, const char *mode)
 	} else {
 		st->string = (char *)buf;
 
-		if ((oflags & O_WRONLY) == 0)
-			st->len = size;
-
 		if (oflags & O_TRUNC)
 			*st->string = '\0';
 
diff --git a/lib/libc/stdio/open_memstream.c b/lib/libc/stdio/open_memstream.c
index 48ae2900f6d..bd96874e959 100644
--- a/lib/libc/stdio/open_memstream.c
+++ b/lib/libc/stdio/open_memstream.c
@@ -1,4 +1,5 @@
-/*	$OpenBSD: open_memstream.c,v 1.1 2013/01/01 17:41:13 mpi Exp $	*/
+/*	$OpenBSD: open_memstream.c,v 1.2 2013/03/27 15:06:25 mpi Exp $	*/
+
 /*
  * Copyright (c) 2011 Martin Pieuchot <mpi@openbsd.org>
  *
@@ -15,8 +16,11 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
+#include <sys/param.h>
+
 #include <errno.h>
 #include <fcntl.h>
+#include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -27,7 +31,7 @@ struct state {
 	char		**pbuf;		/* point to the stream */
 	size_t		 *psize;	/* point to min(pos, len) */
 	size_t		  pos;		/* current position */
-	size_t		  size;		/* allocated size */
+	size_t		  size;		/* number of allocated char */
 	size_t		  len;		/* length of the data */
 };
 
@@ -35,15 +39,17 @@ static int
 memstream_write(void *v, const char *b, int l)
 {
 	struct state	*st = v;
-	int		 i;
 	char		*p;
+	size_t		 i, end;
 
-	if (st->pos + l >= st->size) {
+	end = (st->pos + l);
+
+	if (end >= st->size) {
 		/* 1.6 is (very) close to the golden ratio. */
 		size_t	sz = st->size * 8 / 5;
 
-		if (sz < st->pos + l + 1)
-			sz = st->pos + l + 1;
+		if (sz < end + 1)
+			sz = end + 1;
 		p = realloc(st->string, sz);
 		if (!p)
 			return (-1);
@@ -54,7 +60,7 @@ memstream_write(void *v, const char *b, int l)
 
 	for (i = 0; i < l; i++)
 		st->string[st->pos + i] = b[i];
-	st->pos += i;
+	st->pos += l;
 
 	if (st->pos > st->len) {
 		st->len = st->pos;
@@ -67,52 +73,41 @@ memstream_write(void *v, const char *b, int l)
 }
 
 static fpos_t
-memstream_seek(void *v, fpos_t pos, int w)
+memstream_seek(void *v, fpos_t off, int whence)
 {
 	struct state	*st = v;
-	char		*p;
+	ssize_t		 base = 0;
 
-	switch (w) {
+	switch (whence) {
 	case SEEK_SET:
 		break;
 	case SEEK_CUR:
-		pos += st->pos;
+		base = st->pos;
 		break;
 	case SEEK_END:
-		pos += st->len;
+		base = st->len;
 		break;
-	default:
-		errno = EINVAL;
-		return (-1);
 	}
 
-	if (pos < 0)
+	if (off > SIZE_MAX - base || off < -base) {
+		errno = EOVERFLOW;
 		return (-1);
+	}
 
-	st->pos = pos;
-
-	if (st->pos < st->len)
-		*st->psize = st->pos;
-	else
-		*st->psize = st->len;
+	st->pos = base + off;
+	*st->psize = MIN(st->pos, st->len);
 
-	return (pos);
+	return (st->pos);
 }
 
 static int
 memstream_close(void *v)
 {
 	struct state	*st = v;
-	char		*p;
-#define MIN(x, y) (((x) < (y)) ? (x) : (y))
-
-	*st->psize = MIN(st->pos, st->len);
-	*st->pbuf = st->string;
 
 	free(st);
 
 	return (0);
-#undef MIN
 }
 
 FILE *
@@ -134,11 +129,7 @@ open_memstream(char **pbuf, size_t *psize)
 		return (NULL);
 	}
 
-	if (*psize < 128)
-		st->size = 128;
-	else
-		st->size = *psize;
-
+	st->size = BUFSIZ;
 	if ((st->string = calloc(1, st->size)) == NULL) {
 		free(st);
 		fp->_flags = 0;
diff --git a/lib/libc/stdio/open_wmemstream.c b/lib/libc/stdio/open_wmemstream.c
new file mode 100644
index 00000000000..2b8677c3b6a
--- /dev/null
+++ b/lib/libc/stdio/open_wmemstream.c
@@ -0,0 +1,168 @@
+/*	$OpenBSD: open_wmemstream.c,v 1.1 2013/03/27 15:06:25 mpi Exp $	*/
+
+/*
+ * Copyright (c) 2011 Martin Pieuchot <mpi@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/param.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <wchar.h>
+#include "local.h"
+
+struct state {
+	wchar_t		 *string;	/* actual stream */
+	wchar_t		**pbuf;		/* point to the stream */
+	size_t		 *psize;	/* point to min(pos, len) */
+	size_t		  pos;		/* current position */
+	size_t		  size;		/* number of allocated wchar_t */
+	size_t		  len;		/* length of the data */
+	mbstate_t	  mbs;		/* conversion state of the stream */
+};
+
+static int
+wmemstream_write(void *v, const char *b, int l)
+{
+	struct state	*st = v;
+	wchar_t		*p;
+	size_t		 nmc, len, end;
+
+	end = (st->pos + l);
+
+	if (end >= st->size) {
+		/* 1.6 is (very) close to the golden ratio. */
+		size_t	sz = st->size * 8 / 5;
+
+		if (sz < end + 1)
+			sz = end + 1;
+		p = realloc(st->string, sz * sizeof(wchar_t));
+		if (!p)
+			return (-1);
+		bzero(p + st->size, (sz - st->size) * sizeof(wchar_t));
+		*st->pbuf = st->string = p;
+		st->size = sz;
+	}
+
+	nmc = (st->size - st->pos) * sizeof(wchar_t);
+	len = mbsnrtowcs(st->string + st->pos, &b, nmc, l, &st->mbs);
+	if (len < 0)
+		return (len);
+	st->pos += len;
+
+	if (st->pos > st->len) {
+		st->len = st->pos;
+		st->string[st->len] = L'\0';
+	}
+
+	*st->psize = st->pos;
+
+	return (len);
+}
+
+static fpos_t
+wmemstream_seek(void *v, fpos_t off, int whence)
+{
+	struct state	*st = v;
+	ssize_t		 base = 0;
+
+	switch (whence) {
+	case SEEK_SET:
+		break;
+	case SEEK_CUR:
+		base = st->pos;
+		break;
+	case SEEK_END:
+		base = st->len;
+		break;
+	}
+
+	if (off > (SIZE_MAX / sizeof(wchar_t)) - base || off < -base) {
+		errno = EOVERFLOW;
+		return (-1);
+	}
+
+	/*
+	 * XXX Clearing mbs here invalidates shift state for state-
+	 * dependent encodings, but they are not (yet) supported.
+	 */
+	bzero(&st->mbs, sizeof(st->mbs));
+
+	st->pos = base + off;
+	*st->psize = MIN(st->pos, st->len);
+
+	return (st->pos);
+}
+
+static int
+wmemstream_close(void *v)
+{
+	struct state	*st = v;
+
+	free(st);
+
+	return (0);
+}
+
+FILE *
+open_wmemstream(wchar_t **pbuf, size_t *psize)
+{
+	struct state	*st;
+	FILE		*fp;
+
+	if (pbuf == NULL || psize == NULL) {
+		errno = EINVAL;
+		return (NULL);
+	}
+
+	if ((st = malloc(sizeof(*st))) == NULL)
+		return (NULL);
+
+	if ((fp = __sfp()) == NULL) {
+		free(st);
+		return (NULL);
+	}
+
+	st->size = BUFSIZ * sizeof(wchar_t);
+	if ((st->string = calloc(1, st->size)) == NULL) {
+		free(st);
+		fp->_flags = 0;
+		return (NULL);
+	}
+
+	*st->string = L'\0';
+	st->pos = 0;
+	st->len = 0;
+	st->pbuf = pbuf;
+	st->psize = psize;
+	bzero(&st->mbs, sizeof(st->mbs));
+
+	*pbuf = st->string;
+	*psize = st->len;
+
+	fp->_flags = __SWR;
+	fp->_file = -1;
+	fp->_cookie = st;
+	fp->_read = NULL;
+	fp->_write = wmemstream_write;
+	fp->_seek = wmemstream_seek;
+	fp->_close = wmemstream_close;
+
+	return (fp);
+}