Implement mempcpy(3) and wmempcpy(3)

[kib]

Summary

for Linux source compatibility.

[markj]

lib/libc/string/mempcpy.c

38 ↗

(On Diff #92190)

Shouldn't the restrict qualifier be used in the definition as well?

[kib]

lib/libc/string/mempcpy.c

38 ↗

(On Diff #92190)

I always thought that not.

I was not able to find an answer in the standard from the cursory look, and think that it is not worth the time.

[kib]

Apply restrict to the args in declaration of wmempcpy as well.

[markj]

lib/libc/string/mempcpy.c

38 ↗

(On Diff #92190)

I am not sure either. The diff now uses __restrict in the wmempcpy() definition but not in the mempcpy() definition.

[kib]

lib/libc/string/mempcpy.c

38 ↗

(On Diff #92190)

Oh, I think that adding __restrict to mempcpy is a mistake. Look at the man page text for memcpy(3) about overlapping. On the other hand, memcpy() does has restrict on args.

[kib]

Add __restrict to mempcpy(3) definition as well.

[markj]

lib/libc/string/mempcpy.c

38 ↗

(On Diff #92190)

Indeed, though the memcpy() definition in bcopy.c does not use restrict.