Finish move of clock_* functions to libc. [BZ #24959]

In glibc 2.17, the functions clock_getcpuclockid, clock_getres,
clock_gettime, clock_nanosleep, and clock_settime were moved from
librt.so to libc.so, leaving compatibility stubs behind.  Now that the
dynamic linker no longer insists on finding versioned symbols in the
same library that originally defined them, we do not need the stubs
anymore, and this means we don't need GLIBC_PRIVATE __-prefix aliases
for most of the functions anymore either.  (clock_gettime still needs
one.)  For ports added before 2.17, libc.so needs to provide two
symbol versions for each, the default at GLIBC_2.17 plus a compat
version matching what librt had.

While I'm at it, move the clock_*.c files and their tests from rt/ to
time/.

1 files changed, 9 insertions, 1 deletions

diff --git a/sysdeps/unix/sysv/linux/clock_nanosleep.c b/sysdeps/unix/sysv/linux/clock_nanosleep.c
index 0cb6614dc9..e19e09d197 100644
--- a/sysdeps/unix/sysv/linux/clock_nanosleep.c
+++ b/sysdeps/unix/sysv/linux/clock_nanosleep.c
@@ -21,6 +21,7 @@
 #include <sysdep-cancel.h>
 #include "kernel-posix-cpu-timers.h"
 
+#include <shlib-compat.h>
 
 /* We can simply use the syscall.  The CPU clocks are not supported
    with this function.  */
@@ -41,4 +42,11 @@ __clock_nanosleep (clockid_t clock_id, int flags, const struct timespec *req,
   return (INTERNAL_SYSCALL_ERROR_P (r, err)
 	  ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
 }
-weak_alias (__clock_nanosleep, clock_nanosleep)
+
+versioned_symbol (libc, __clock_nanosleep, clock_nanosleep, GLIBC_2_17);
+/* clock_nanosleep moved to libc in version 2.17;
+   old binaries may expect the symbol version it had in librt.  */
+#if SHLIB_COMPAT (libc, GLIBC_2_2, GLIBC_2_17)
+strong_alias (__clock_nanosleep, __clock_nanosleep_2);
+compat_symbol (libc, __clock_nanosleep_2, clock_nanosleep, GLIBC_2_2);
+#endif