commit 08a70a65670ee801d4190ec122d42aa4a9a997a9
author Jonathan Wakely <jwakely@redhat.com> Wed Feb 26 15:32:34 2020 +0000
committer Jonathan Wakely <jwakely@redhat.com> Wed Feb 26 15:32:34 2020 +0000
tree 5314180e93aa09ef43a7703658f02786ffc317b1
parent 30cb4c78ea6563177c43f897e480d9993c38c0ed

libstdc++: Replace glibc-specific check for clock_gettime (PR 93325)

It's wrong to assume that clock_gettime is unavailable on any *-*-linux*
target that doesn't have glibc 2.17 or later. Use a generic test instead
of using __GLIBC_PREREQ. Only do that test when is_hosted=yes so that we
don't get an error for cross targets without a working linker.

This ensures that C library's clock_gettime will be used on non-glibc
targets, instead of an incorrect syscall to SYS_clock_gettime.

Backport from mainline
2020-01-28  Jonathan Wakely  <jwakely@redhat.com>

	PR libstdc++/93325
	* acinclude.m4 (GLIBCXX_ENABLE_LIBSTDCXX_TIME): Use AC_SEARCH_LIBS for
	clock_gettime instead of explicit glibc version check.
	* configure: Regenerate.