Notice clock_* functions in librt.so for old GLIBC_2.18 builds?

[Roland McGrath]

> On 02/21/2014 06:54 PM, Roland McGrath wrote:
> >> The question that remains is: How do we prevent this from happening
> >> again?

Also, someone should try turning on -Wundef in the build and see if it
generates any warnings.  It should generate one for the case of the missing
Versions.def entry.  (It's easy to test in any configuration--even a
momentarily hand-hacked one--with a shlib-versions third column of
GLIBC_2.17 or newer, since you can drop the GLIBC_2.17 line from
Versions.def and check nm rt/clock-compat.os for being empty as it should
be.)

Perhaps something annoying will come up.  But I tend to think that if
-Wundef turns up any warnings (other than an intentionally-induced one for
abi-versions.h misgeneration, which one should verify it does), we should
just fix the uses and then put -Werror=undef into +gccwarn.  Ever intending
to evaluate undefined tokens in cpp expressions just seems sloppy off hand.


Thanks,
Roland