commit f289e656ec8221756519a601042bc9fbe1b310fb Author: Florian Weimer Date: Fri Feb 8 10:21:56 2019 +0100 rt: Turn forwards from librt to libc into compat symbols [BZ #24194] As the result of commit 6e6249d0b461b952d0f544792372663feb6d792a ("BZ#14743: Move clock_* symbols from librt to libc."), in glibc 2.17, clock_gettime, clock_getres, clock_settime, clock_getcpuclockid, clock_nanosleep were added to libc, and the file rt/clock-compat.c was added with forwarders to the actual implementations in libc. These forwarders were wrapped in #if SHLIB_COMPAT (librt, GLIBC_2_2, GLIBC_2_17) so that they are not present for newer architectures (such as powerpc64le) with a 2.17 or later ABI baseline. But the forwarders were not marked as compatibility symbols. As a result, on older architectures, historic configure checks such as AC_CHECK_LIB(rt, clock_gettime) still cause linking against librt, even though this is completely unnecessary. It also creates a needless porting hazard because architectures behave differently when it comes to symbol availability. Reviewed-by: Carlos O'Donell diff --git a/rt/clock-compat.c b/rt/clock-compat.c index f816973c05c29d5d..11e71aa89019b173 100644 --- a/rt/clock-compat.c +++ b/rt/clock-compat.c @@ -30,14 +30,16 @@ #if HAVE_IFUNC # undef INIT_ARCH # define INIT_ARCH() -# define COMPAT_REDIRECT(name, proto, arglist) libc_ifunc (name, &__##name) +# define COMPAT_REDIRECT(name, proto, arglist) libc_ifunc (name, &__##name) \ + compat_symbol (librt, name, name, GLIBC_2_2); #else # define COMPAT_REDIRECT(name, proto, arglist) \ int \ name proto \ { \ return __##name arglist; \ - } + } \ + compat_symbol (librt, name, name, GLIBC_2_2); #endif COMPAT_REDIRECT (clock_getres,