Re: [libvirt] [PATCH 1/9] Add some autoconf helper macros for checking for libraries

On 01/11/2013 03:37 AM, Daniel P. Berrange wrote: But in reality, there are several instances where asking for one feature implies that a particular library becomes mandatory. For example, even if you don't specify --with-yajl at all, merely compiling './configure --with-qemu' on a system with qemu 1.x will behave as if you had done --with-yajl=yes instead of --with-yajl=check. Hmm, another thought - when do we decide which features need which libraries? One style is to probe for all libraries first, and then run through features, failing the features that are lacking a dependent library. This would still benefit from the idea of listing all errors at once, instead of one error per run. However, if you disable features (such as --without-libvirtd), checking for those libraries could be a waste of configure time. Another style would be to default all libraries to 'no', then run through all features, and each feature changes the libraries it depends on to either 'check' (if the dependency is optional) or 'yes' (if mandatory), then do the library checks (hitting just the libraries that are needed), and finally back to the feature checks to see the results of the libraries. But all of this is grounds for further improvement, and doesn't really impact the usefulness of your current series. -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org