[PATCH] detect incompatible aliases (PR c/81854)

[Joseph Myers]

On Mon, 2 Oct 2017, Steve Ellcey wrote:

> I think there is more fallout from this patch. Â The libatomic library
> can use ifuncs and right now it is not working on aarch64 (testing a
> proposed patch I sent) because the ifunc check fails due to the new
> warnings. Â I believe this can be reproduced with ToT on x86 or arm as
> they use ifuncs in the checked in sources but I have not tried that
> yet. Â Note that the build does not fail, it is just that the check for
> ifunc support fails and thus the library is built without them.

In the ARM case we don't enable ifunc attribute support by default.  I 
think we *should* add arm*-* to that case statement to enable it by 
default (for GNU/Linux targets); it just so happens the absence for ARM 
doesn't break building glibc because all IFUNCs in glibc on ARM are 
defined in .S files, not in C code.

-- 
Joseph S. Myers
joseph@codesourcery.com