[PATCH v2 1/9] Add configure check to test if gcc supports attribute ifunc.

[Florian Weimer]

On 08/17/2016 12:37 PM, Stefan Liebler wrote:
> My suggestion is to check for gcc-attribute-ifunc support while
> configuring glibc.
>
> If it is available (currently on intel, s390 and on fedora/rhel for
> power and arm) the gcc-attribute-ifunc will be used for ifunc-macros to
> get rid of the false debug-information.
>
> If it is not available the current approach for ifunc-macros will be
> used instead. This way the debug-information is not correct, but it does
> not break current configurations without the gcc-support.
> Furthermore the "assembler hacks" for ifunc-handling are not scattered
> in multiple files but are used only indirect via ifunc-macros and can
> simply removed in libc-symbols.h in future.
> If glibc is configured with --enable-multi-arch then configure will dump
> a warning that gcc does not support attribute ifunc and it can be
> enabled by configuring gcc with --enable-gnu-indirect-function.

This looks like a good plan to me.

Thanks,
Florian