Re: [libvirt] [PATCH] tests: Handle networkxml2argvtest being configure --localstatedir dependant

On 06/25/2011 10:10 AM, Matthias Bolte wrote: > 2011/6/25 Eric Blake <eblake(a)redhat.com&gt;: >> On 06/25/2011 06:41 AM, Matthias Bolte wrote: >>> networkxml2argvtest indirectly calls networkDnsmasqLeaseFileName >>> that depends on configure --localstatedir. Therefore, the .argv >>> files used in the test have to be created with this localstatedir. >>> >>> Move the .argv to .argv.in files with a @localstatedir@ placeholder. >> >> Will this work in VPATH builds?  Previously, we have done hacks where >> the test directory can provide an override string; if the override is >> NULL (the default, for use in libvirtd), then use @localstatedir@, but >> if the override is provided (from the test case), then use that instead. > > Where are we doing that in libvirtd, I can't find something like that. > > Also how would you do that in general? Environment variable? > LD_PRELOAD to replace networkDnsmasqLeaseFileName for testing > (assuming that LD_PRELOAD works in this case)? Function override.  See for example how openvz_conf.h declares openvzLocateConfFile, which is normally set to openvzLocateConfFileDefault and uses configure arguments to determine the string to create, but within tests/openvzutilstest, is overridden to a test-only variant that hard-codes the location to instead be relative to the test directory. That is, the networkDnsmasqLeaseFileName function can easily be reworked into a function pointer, with the current definition being installed by default, but with an alternate function pointer installed during the test that avoids any reference to configure arguments.