summaryrefslogtreecommitdiff
path: root/libc/stdio/_trans2r.c
diff options
context:
space:
mode:
Diffstat (limited to 'libc/stdio/_trans2r.c')
-rw-r--r--libc/stdio/_trans2r.c75
1 files changed, 75 insertions, 0 deletions
diff --git a/libc/stdio/_trans2r.c b/libc/stdio/_trans2r.c
new file mode 100644
index 000000000..d33d9eba8
--- /dev/null
+++ b/libc/stdio/_trans2r.c
@@ -0,0 +1,75 @@
+/* Copyright (C) 2004 Manuel Novoa III <mjn3@codepoet.org>
+ *
+ * GNU Library General Public License (LGPL) version 2 or later.
+ *
+ * Dedicated to Toni. See uClibc/DEDICATION.mjn3 for details.
+ */
+
+#include "_stdio.h"
+
+/* Function to handle transition to reading.
+ * Initialize or verify the stream's orientation (even if writeonly).
+ * Check that the stream is readable.
+ * If currently reading, check that we can transition to writing.
+ * C99 requires that we not be reading, but attempting to
+ * auto-transition by commiting the write buffer is a configurable
+ * option.
+ * Returns 0 on success and EOF otherwise.
+ *
+ * Notes:
+ * There are two function signatures, depending on wchar support,
+ * since with no wchar support the orientation is narrow by default.
+ */
+
+#ifdef __UCLIBC_HAS_WCHAR__
+int __stdio_trans2r_o(FILE * __restrict stream, int oflag)
+#else
+int __stdio_trans2r(FILE * __restrict stream)
+#endif
+{
+ __STDIO_STREAM_VALIDATE(stream);
+ assert(!__STDIO_STREAM_IS_READING(stream));
+
+#ifdef __UCLIBC_HAS_WCHAR__
+ if (!(stream->__modeflags & oflag)) {
+ if (stream->__modeflags & (__FLAG_NARROW|__FLAG_WIDE)) {
+ __UNDEFINED_OR_NONPORTABLE;
+ goto DO_EBADF;
+ }
+ stream->__modeflags |= oflag;
+ }
+#endif
+
+ if (stream->__modeflags & __FLAG_WRITEONLY) {
+ DO_EBADF:
+ __set_errno(EBADF);
+ ERROR:
+ __STDIO_STREAM_SET_ERROR(stream);
+ __STDIO_STREAM_VALIDATE(stream);
+ return EOF;
+ }
+
+ if (__STDIO_STREAM_IS_WRITING(stream)) {
+#ifdef __UCLIBC_HAS_STDIO_AUTO_RW_TRANSITION__
+ if (__STDIO_COMMIT_WRITE_BUFFER(stream)) { /* commit failed! */
+ goto ERROR;
+ }
+ assert(!__STDIO_STREAM_BUFFER_WUSED(stream));
+
+ __STDIO_STREAM_DISABLE_PUTC(stream);
+ __STDIO_STREAM_CLEAR_WRITING(stream);
+#else
+ /* C99: Output shall not be directly followed by input without an
+ intervening call to the fflush function or to a file positioning
+ function (fseek, fsetpos, or rewind). */
+ __UNDEFINED_OR_NONPORTABLE;
+ goto DO_EBADF;
+#endif
+ }
+
+ __STDIO_STREAM_SET_READING(stream);
+ /* getc macro is enabled when data is read into buffer. */
+
+ __STDIO_STREAM_VALIDATE(stream);
+ return 0;
+}