As the result of commit 6e6249d0b4
("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 <carlos@redhat.com>
This patch uses the libc_ifunc macro to create already existing ifunc functions
clock_getres, clock_gettime, clock_settime, clock_getcpuclockid and
clock_nanosleep. If HAVE_IFUNC is defined, the macro COMPAT_REDIRECT uses
the libc_ifunc macro.
Furthermore some whitespace damage is cleaned.
ChangeLog:
* rt/clock-compat.c (COMPAT_REDIRECT): Use libc_ifunc macro.
