1 files changed, 271 insertions, 0 deletions
diff --git a/lib/libc/stdio/open_wmemstream.c b/lib/libc/stdio/open_wmemstream.c
new file mode 100644
index 0000000..cf2968a
--- /dev/null
+++ b/lib/libc/stdio/open_wmemstream.c
@@ -0,0 +1,271 @@
+/*-
+ * Copyright (c) 2013 Advanced Computing Technologies LLC
+ * Written by: John H. Baldwin <jhb@FreeBSD.org>
+ * All rights reserved.
+ *
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include "namespace.h"
+#include <assert.h>
+#include <errno.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <wchar.h>
+#include "un-namespace.h"
+
+/* XXX: There is no FPOS_MAX.  This assumes fpos_t is an off_t. */
+#define	FPOS_MAX	OFF_MAX
+
+struct wmemstream {
+	wchar_t **bufp;
+	size_t *sizep;
+	ssize_t len;
+	fpos_t offset;
+	mbstate_t mbstate;
+};
+
+static int
+wmemstream_grow(struct wmemstream *ms, fpos_t newoff)
+{
+	wchar_t *buf;
+	ssize_t newsize;
+
+	if (newoff < 0 || newoff >= SSIZE_MAX / sizeof(wchar_t))
+		newsize = SSIZE_MAX / sizeof(wchar_t) - 1;
+	else
+		newsize = newoff;
+	if (newsize > ms->len) {
+		buf = realloc(*ms->bufp, (newsize + 1) * sizeof(wchar_t));
+		if (buf != NULL) {
+#ifdef DEBUG
+			fprintf(stderr, "WMS: %p growing from %zd to %zd\n",
+			    ms, ms->len, newsize);
+#endif
+			wmemset(buf + ms->len + 1, 0, newsize - ms->len);
+			*ms->bufp = buf;
+			ms->len = newsize;
+			return (1);
+		}
+		return (0);
+	}
+	return (1);
+}
+
+static void
+wmemstream_update(struct wmemstream *ms)
+{
+
+	assert(ms->len >= 0 && ms->offset >= 0);
+	*ms->sizep = ms->len < ms->offset ? ms->len : ms->offset;
+}
+
+/*
+ * Based on a starting multibyte state and an input buffer, determine
+ * how many wchar_t's would be output.  This doesn't use mbsnrtowcs()
+ * so that it can handle embedded null characters.
+ */
+static size_t
+wbuflen(const mbstate_t *state, const char *buf, int len)
+{
+	mbstate_t lenstate;
+	size_t charlen, count;
+
+	count = 0;
+	lenstate = *state;
+	while (len > 0) {
+		charlen = mbrlen(buf, len, &lenstate);
+		if (charlen == (size_t)-1)
+			return (-1);
+		if (charlen == (size_t)-2)
+			break;
+		if (charlen == 0)
+			/* XXX: Not sure how else to handle this. */
+			charlen = 1;
+		len -= charlen;
+		buf += charlen;
+		count++;
+	}
+	return (count);
+}
+
+static int
+wmemstream_write(void *cookie, const char *buf, int len)
+{
+	struct wmemstream *ms;
+	ssize_t consumed, wlen;
+	size_t charlen;
+
+	ms = cookie;
+	wlen = wbuflen(&ms->mbstate, buf, len);
+	if (wlen < 0) {
+		errno = EILSEQ;
+		return (-1);
+	}
+	if (!wmemstream_grow(ms, ms->offset + wlen))
+		return (-1);
+
+	/*
+	 * This copies characters one at a time rather than using
+	 * mbsnrtowcs() so it can properly handle embedded null
+	 * characters.
+	 */
+	consumed = 0;
+	while (len > 0 && ms->offset < ms->len) {
+		charlen = mbrtowc(*ms->bufp + ms->offset, buf, len,
+		    &ms->mbstate);
+		if (charlen == (size_t)-1) {
+			if (consumed == 0) {
+				errno = EILSEQ;
+				return (-1);
+			}
+			/* Treat it as a successful short write. */
+			break;
+		}
+		if (charlen == 0)
+			/* XXX: Not sure how else to handle this. */
+			charlen = 1;
+		if (charlen == (size_t)-2) {
+			consumed += len;
+			len = 0;
+		} else {
+			consumed += charlen;
+			buf += charlen;
+			len -= charlen;
+			ms->offset++;
+		}
+	}
+	wmemstream_update(ms);
+#ifdef DEBUG
+	fprintf(stderr, "WMS: write(%p, %d) = %zd\n", ms, len, consumed);
+#endif
+	return (consumed);
+}
+
+static fpos_t
+wmemstream_seek(void *cookie, fpos_t pos, int whence)
+{
+	struct wmemstream *ms;
+	fpos_t old;
+
+	ms = cookie;
+	old = ms->offset;
+	switch (whence) {
+	case SEEK_SET:
+		/* _fseeko() checks for negative offsets. */
+		assert(pos >= 0);
+		ms->offset = pos;
+		break;
+	case SEEK_CUR:
+		/* This is only called by _ftello(). */
+		assert(pos == 0);
+		break;
+	case SEEK_END:
+		if (pos < 0) {
+			if (pos + ms->len < 0) {
+#ifdef DEBUG
+				fprintf(stderr,
+				    "WMS: bad SEEK_END: pos %jd, len %zd\n",
+				    (intmax_t)pos, ms->len);
+#endif
+				errno = EINVAL;
+				return (-1);
+			}
+		} else {
+			if (FPOS_MAX - ms->len < pos) {
+#ifdef DEBUG
+				fprintf(stderr,
+				    "WMS: bad SEEK_END: pos %jd, len %zd\n",
+				    (intmax_t)pos, ms->len);
+#endif
+				errno = EOVERFLOW;
+				return (-1);
+			}
+		}
+		ms->offset = ms->len + pos;
+		break;
+	}
+	/* Reset the multibyte state if a seek changes the position. */
+	if (ms->offset != old)
+		memset(&ms->mbstate, 0, sizeof(ms->mbstate));
+	wmemstream_update(ms);
+#ifdef DEBUG
+	fprintf(stderr, "WMS: seek(%p, %jd, %d) %jd -> %jd\n", ms,
+	    (intmax_t)pos, whence, (intmax_t)old, (intmax_t)ms->offset);
+#endif
+	return (ms->offset);
+}
+
+static int
+wmemstream_close(void *cookie)
+{
+
+	free(cookie);
+	return (0);
+}
+
+FILE *
+open_wmemstream(wchar_t **bufp, size_t *sizep)
+{
+	struct wmemstream *ms;
+	int save_errno;
+	FILE *fp;
+
+	if (bufp == NULL || sizep == NULL) {
+		errno = EINVAL;
+		return (NULL);
+	}
+	*bufp = calloc(1, sizeof(wchar_t));
+	if (*bufp == NULL)
+		return (NULL);
+	ms = malloc(sizeof(*ms));
+	if (ms == NULL) {
+		save_errno = errno;
+		free(*bufp);
+		*bufp = NULL;
+		errno = save_errno;
+		return (NULL);
+	}
+	ms->bufp = bufp;
+	ms->sizep = sizep;
+	ms->len = 0;
+	ms->offset = 0;
+	memset(&ms->mbstate, 0, sizeof(mbstate_t));
+	wmemstream_update(ms);
+	fp = funopen(ms, NULL, wmemstream_write, wmemstream_seek,
+	    wmemstream_close);
+	if (fp == NULL) {
+		save_errno = errno;
+		free(ms);
+		free(*bufp);
+		*bufp = NULL;
+		errno = save_errno;
+		return (NULL);
+	}
+	fwide(fp, 1);
+	return (fp);
+}