Where does <sys/features.h> come from?

Peter Dufault dufault at hda.com
Wed Apr 21 21:18:53 UTC 2010

On Apr 21, 2010, at 4:43 , Joel Sherrill wrote:

> It is part of newlib.  But be careful.  Chris Johns is working on an
> mmap() implementation that is compliant but won't support
> mmap files.

That's fine, once that work is in I assume it will include a <sys/mmap.h>, mmap() and munmap() so that things will compile, build, and run properly, right?  Until then, though, _POSIX_MAPPED_FILES should be undefined.

Here's one that given an appropriate <sys/mmap.h> is compliant but won't support mmap files:

void *mmap(void *addr, size_t len, int prot, int flags, int fildes, off_t off) {
	errno = ENOSYS;
	return MAP_FAILED;

int munmap(void *addr, size_t len) {
	errno = ENOSYS;
	return -1;

Peter Dufault
HD Associates, Inc.      Software and System Engineering

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