Finish <stdio_ext.h>.

Implement __freading and __fwriting, and clarify the documentation that was
the cause of these not being implemented for years.

Bug: http://b/17157253
Test: ran tests
Change-Id: I89542c8131b13889e2585417a024050ecf2abcb7

1 files changed, 3 insertions, 7 deletions

diff --git a/libc/stdio/stdio_ext.cpp b/libc/stdio/stdio_ext.cpp
index ebc705c87..8cf4f4b3d 100644
--- a/libc/stdio/stdio_ext.cpp
+++ b/libc/stdio/stdio_ext.cpp
@@ -39,17 +39,13 @@ size_t __fbufsize(FILE* fp) {
   return fp->_bf._size;
 }
 
-/* For a _SRW stream, we don't know whether we last read or wrote.
 int __freading(FILE* fp) {
-  return (fp->_flags & _SRD) != 0 || ...;
+  return (fp->_flags & __SRD) != 0;
 }
-*/
 
-/* For a _SRW stream, we don't know whether we last read or wrote.
-int __fwriting(FILE*) {
-  return (fp->_flags & _SWR) != 0 || ...;
+int __fwriting(FILE* fp) {
+  return (fp->_flags & __SWR) != 0;
 }
-*/
 
 int __freadable(FILE* fp) {
   return (fp->_flags & (__SRD|__SRW)) != 0;