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

[Joseph Myers]

On Tue, 9 Aug 2016, Florian Weimer wrote:

> > I'm concerned about requiring non-default configure options.  Various
> > architectures support IFUNC in binutils and may have done so for a long
> > time, but without the option being enabled in GCC by default.  There
> > should be a much more detailed analysis of which architectures have IFUNC
> > support in binutils, when it was added, and correspondingly, whether it's
> > enabled by default in GCC for those architectures and, if so, when such
> > enabling was added.
> 
> Is this really necessary?  Can't we rely on architecture maintainers to do
> this?

If you're proposing increasing build requirements, you need to give the 
community a proper understanding of what the proposed change is.  In this 
case, the impacts depend on the architecture, as some architectures (e.g. 
AArch64, ARM, PowerPC, SPARC) have IFUNC support but do not enable it by 
default in GCC, while on some other architectures, a nondefault GCC 
configure option would be needed to disable the support.

-- 
Joseph S. Myers
joseph@codesourcery.com