On Monday 27 February 2012, Brad King wrote: > On 2/27/2012 3:37 PM, Michael Wild wrote: > > On 02/27/2012 09:15 PM, Alexander Neundorf wrote: > >> When the FooConfig.cmake has been found, Foo_FOUND is set to TRUE: > >> // Set a variable marking whether the package was found. > >> > >> std::string foundVar = this->Name; > >> foundVar += "_FOUND"; > >> > >> This means it is true in all cases that the Config.cmake file has been > >> found (and the version was compatible). > > The find_package command is acting as a primitive like find_library from > the point of view of setting Foo_DIR, and that can be tested directly to > see if the config file was found. That leaves room to change the way > we set Foo_FOUND. We could add a policy that in NEW behavior unsets > Foo_FOUND completely before loading FooConfig. After FooConfig has been > loaded it detects whether Foo_FOUND is now defined. If set, use that > value. If not set, set it to true as it is now. That will give the > FooConfig file a chance to set the result.
There is now a branch find_package_set_FOUND_VariableInConfigFile on stage. It behaves almost as you suggested: the _FOUND variable is only removed before the Config file is loaded, if the variable exists and is false. So if some Config file would test for the previous value of _FOUND, it will still get the same result. After the Config file is loaded, it checks whether _FOUND now exists and whether it is set to FALSE. Only in this case find_package() now sets _FOUND to FALSE although a Config file has been found and could be processed. I didn't add a policy. I'm not sure it is necessary. I'm tempted to consider this a bug fix, and whoever relies on the fact that Foo_FOUND=FALSE will be overridden has a broken setup. However, if this was the case, it would hit users of the installed Config files. So, I'm not sure about the policy. I can add one if you consider it necessary. Alex -- Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Follow this link to subscribe/unsubscribe: http://public.kitware.com/cgi-bin/mailman/listinfo/cmake-developers
