Since no room left in the _flags, reuse __SALC for O_APPEND.

It helps to remove _fcntl() call from _ftello() and optimize seek position
calculation in _swrite().

MFC after:      3 weeks

5 files changed, 31 insertions, 19 deletions

diff --git a/lib/libc/stdio/fdopen.c b/lib/libc/stdio/fdopen.c
index b936998..8bd9c2d 100644
--- a/lib/libc/stdio/fdopen.c
+++ b/lib/libc/stdio/fdopen.c
@@ -91,7 +91,10 @@ fdopen(int fd, const char *mode)
 	 * O_APPEND bit set, assert __SAPP so that __swrite() caller
 	 * will _sseek() to the end before write.
 	 */
-	if ((oflags & O_APPEND) && !(fdflags & O_APPEND))
+	/* XXX: Reuse __SALC for O_APPEND. */
+	if (fdflags & O_APPEND)
+		fp->_flags |= __SALC;
+	else if (oflags & O_APPEND)
 		fp->_flags |= __SAPP;
 	fp->_file = fd;
 	fp->_cookie = fp;
diff --git a/lib/libc/stdio/fopen.c b/lib/libc/stdio/fopen.c
index b08e336..b26f637 100644
--- a/lib/libc/stdio/fopen.c
+++ b/lib/libc/stdio/fopen.c
@@ -91,7 +91,10 @@ fopen(const char * __restrict file, const char * __restrict mode)
 	 * we can do about this.  (We could set __SAPP and check in
 	 * fseek and ftell.)
 	 */
-	if (oflags & O_APPEND)
+	if (oflags & O_APPEND) {
+		/* XXX: Reuse __SALC for O_APPEND. */
+		fp->_flags |= __SALC;
 		(void)_sseek(fp, (fpos_t)0, SEEK_END);
+	}
 	return (fp);
 }
diff --git a/lib/libc/stdio/freopen.c b/lib/libc/stdio/freopen.c
index 4dcd50f..8b68bac 100644
--- a/lib/libc/stdio/freopen.c
+++ b/lib/libc/stdio/freopen.c
@@ -240,8 +240,11 @@ finish:
 	 * we can do about this.  (We could set __SAPP and check in
 	 * fseek and ftell.)
 	 */
-	if (oflags & O_APPEND)
+	if (oflags & O_APPEND) {
+		/* XXX: Reuse __SALC for O_APPEND. */
+		fp->_flags |= __SALC;
 		(void) _sseek(fp, (fpos_t)0, SEEK_END);
+	}
 	FUNLOCKFILE(fp);
 	return (fp);
 }
diff --git a/lib/libc/stdio/ftell.c b/lib/libc/stdio/ftell.c
index 745d500..0d2222b 100644
--- a/lib/libc/stdio/ftell.c
+++ b/lib/libc/stdio/ftell.c
@@ -88,7 +88,6 @@ _ftello(FILE *fp, fpos_t *offset)
 {
 	fpos_t pos;
 	size_t n;
-	int dflags;
 
 	if (fp->_seek == NULL) {
 		errno = ESPIPE;			/* historic practice */
@@ -120,21 +119,24 @@ _ftello(FILE *fp, fpos_t *offset)
 		if (HASUB(fp))
 			pos -= fp->_r;  /* Can be negative at this point. */
 	} else if ((fp->_flags & __SWR) && fp->_p != NULL) {
-		dflags = 0;
-		if (fp->_flags & __SAPP)
-			dflags = O_APPEND;
-		else if (fp->_file != -1 &&
-			 (dflags = _fcntl(fp->_file, F_GETFL)) < 0)
-			return (1);
-		if ((dflags & O_APPEND) &&
-		    (pos = _sseek(fp, (fpos_t)0, SEEK_END)) == -1) {
-			if ((fp->_flags & __SOPT) || __sflush(fp) ||
-			    (pos = _sseek(fp, (fpos_t)0, SEEK_CUR)) == -1)
-				return (1);
-			else {
-				*offset = pos;
-				return (0);
+		/* XXX: Reuse __SALC for O_APPEND. */
+		if (fp->_flags & (__SAPP|__SALC)) {
+			int serrno = errno;
+
+			errno = 0;
+			if ((pos = _sseek(fp, (fpos_t)0, SEEK_END)) == -1) {
+				if (errno == ESPIPE ||
+				    (fp->_flags & __SOPT) || __sflush(fp) ||
+				    (pos =
+				    _sseek(fp, (fpos_t)0, SEEK_CUR)) == -1)
+					return (1);
+				else {
+					errno = serrno;
+					*offset = pos;
+					return (0);
+				}
 			}
+			errno = serrno;
 		}
 		/*
 		 * Writing.  Any buffered characters cause the
diff --git a/lib/libc/stdio/stdio.c b/lib/libc/stdio/stdio.c
index 44ee0ab..fc2e74b 100644
--- a/lib/libc/stdio/stdio.c
+++ b/lib/libc/stdio/stdio.c
@@ -117,7 +117,8 @@ _swrite(FILE *fp, char const *buf, int n)
 	ret = (*fp->_write)(fp->_cookie, buf, n);
 	/* __SOFF removed even on success in case O_APPEND mode is set. */
 	if (ret >= 0) {
-		if ((fp->_flags & (__SAPP|__SOFF)) == (__SAPP|__SOFF) &&
+		/* XXX: Reuse __SALC for O_APPEND. */
+		if ((fp->_flags & __SOFF) && !(fp->_flags & __SALC) &&
 		    fp->_offset <= OFF_MAX - ret)
 			fp->_offset += ret;
 		else