On 01/15/2018 05:39 PM, Andrea Bolognani wrote:
On Mon, 2018-01-15 at 16:36 +0100, Michal Privoznik wrote:
So, one way to solve this once and for all would be to:
* try looking up readline through pkg-config. If that works, then we already know we're compiling against a recent readline version and everything will work;
I just found out that this will not work - even though there is readline.pc.in in the readline repo, they are lacking rule to install the .pc file. So nobody ships that. For instance, on my rawhide box:
[root@fedora ~]# rpm -q readline readline-7.0-5.fc26.x86_64 [root@fedora ~]# rpm -ql readline | grep \.pc [root@fedora ~]#
Ouch.
(Note the .pc file would be in the readline-devel package, not in the runtime one. Still, I've checked on my Rawhide guest and it's not there.)
Ah, right.
At least FreeBSD ships it, though:
# pkg list readline | grep pc$ /usr/local/libdata/pkgconfig/readline.pc
is this GNU readline? I've heard that FreeBSD is ditching GNU software.
Not sure about brew. Not having access to a macOS box is really annoying in this kind of scenario.
* if readline's pkg-config file is not available, try linking against it the old way. This will succeed on oldish versions like the one shipped with CentOS but fail because of missing functions on macOS.
1: ^^^
I should have commented earlier too - what good it is to switch to pkg-config if we're keeping the old way of detecting the library (with this patch included) anyway?
We wouldn't need to include this patch: we could just assume a readline new enough to provide a .pc file contains all the functionality we need.
Well, what if isn't? We would just disable readline? We can't because you're advocating for linking the old way [1]. However, that wouldn't work on systems where we require more than just -lreadline (which is current situation). Currently, the problem is that my code requires this rl_completion_quote_character variable from readline.h. It's not a function, it's a variable. And if not present, compilation fails. So what should we do if pkg-config fails?
Therefore I think we should merge this patch and switch to pkg-config later (when distros have it).
Well, we're running out of time for 4.0.0 anyway, so
Reviewed-by: Andrea Bolognani <abologna@redhat.com>
Agreed, pushed. Thanks. Michal