Re: Require GCC 6.2 or later to build glibc

[Joseph Myers <joseph at codesourcery dot com>]

On Fri, 1 Feb 2019, Gabriel F. T. Gomes wrote:

> On Thu, Jan 31 2019, Joseph Myers wrote:
> > 
> > Thus, this patch increases the minimum to 6.2, removing the
> > documentation of the separate requirement for powerpc64le.  It does
> > not remove the powerpc64le configure test, or any __GNUC_PREREQ that
> > could be removed as not being in installed headers or files shared
> > with gnulib; I think such cleanups are best done separately.
> 
> I'd like to keep the tests for powerpc64le requirements, namely, the
> checks for the presence of quad-precision builtins, and POWER8 as target
> (sysdeps/powerpc/powerpc64/le/configure.ac).  Was it your intention to
> suggest that we should remove the check for the builtins or are these
> cleanups about __GNUC_PREREQ alone?

I'd suggest removing the libc_cv_compiler_powerpc64le_binary128_ok 
configure test, as well as __GNUC_PREREQ calls, since the minimum GCC 
version should imply those built-in functions are available.  I think the 
point of such configure tests (for conditions that, if not met, would 
result in a build failure anyway) is to ensure a helpful early error 
saying what the problem is in the most likely cases of something wrong 
with the build tools (such as GCC being too old) - not to cover every 
theoretically possible form of compiler breakage (such as a 6.2 compiler 
somehow having had support for those built-in functions removed).

-- 
Joseph S. Myers
joseph@codesourcery.com