They are supposed to be macros, according to the C standards. This ordinarily doesn't matter, but it can be detected by #ifdef, as in the following program:
#include <stdio.h>
#ifdef stdin
int main(void) {
puts("stdin is a macro");
}
#endif
Now rewind() will always be called as a function. In combination with an update to the rewind() function in ORCALib, this will ensure that the error indicator is always cleared, as required by the C standards.
It had been changed to reflect changes in the ORCALib code that added a second putback buffer element, but those changes were problematic and have been reverted for now. (It's also not clear if ORCALib binaries with the larger putback buffer were ever distributed--at the least, they aren't on Opus ][ or in any of the ORCA/C 2.2.0 beta releases.)
The macro was slightly broken in that its 'buf' argument might be evaluated twice. This could be a problem if it was, e.g., a call to an allocation function.
This is needed to ensure correct behavior in cases where the macro is bypassed to access the library function, e.g. by enclosing the function name in parentheses or by taking its address.
