fwide.c\stdio\src - musl - musl - an implementation of the standard library for Linux-based systems

#include <wchar.h>
#include "stdio_impl.h"
#define SH (8*sizeof(int)-1)
#define NORMALIZE(x) ((x)>>SH | -((-(x))>>SH))
int fwide(FILE *f, int mode)
{
	FLOCK(f);
	if (!f->mode) mode = f->mode = NORMALIZE(mode);
	FUNLOCK(f);
	return mode;
}