non-POSIX use in yacc with getdate.y

[Greg Hudson]

On 09/25/2018 06:46 AM, Osipov, Michael wrote:
> I have recently compiled MIT Kerberos 1.16.1 on HP-UX and yacc failed with:
> 
>> "./kadmin/cli/getdate.y", line 180: fatal error: invalid escape, or illegal reserved word: expect
> 
> Change introduced in
> https://github.com/krb5/krb5/commit/28fd0a934cdc7b3b42ce213c6d334d4edf1ab591#diff-db7f4e6f3883dd26b97f7b3e10697846R180.

That was part of a series of changes to eliminate all warnings in build 
under clang (gcc still issues some warnings).  I didn't notice at the 
time that we were using an extension in a nominally yacc-compatible grammar.

Aside from the options you listed, we could check the bison output into 
the tree like we do with lib/krb5/krb/x-deltat.y.  But we might just 
revert the commit and live with the warning.  That warning shouldn't 
cause an error in a -Werror build since it isn't coming from the compiler.