On Thu, Dec 10, 2015 at 08:50:10 -0500, Brad King wrote: > That is a long-standing subtlety introduced without discussion, review, > or tests here: > > BUG: change in how set cache overrides local definitions. Should mainly be a > NOP change for most cases > https://cmake.org/gitweb?p=cmake.git;a=commitdiff;h=f52d37c2 > > IIRC there was confusion at the time in the case of > > set(var 1) > set(var 2 CACHE STRING ...) > message("${var}") # prints "1" before the above change.
The above commit has the same behavior as it does today: first configure != subsequent configure, so I don't see the confusion as being *less* after the fix since any existing tree wouldn't say "2" either, but I suppose it was something about dashboards doing clean builds. > On 12/09/2015 05:35 PM, Ben Boeckel wrote: > > I think a policy to remove the unset(var) behavior should be added since > > the current behavior means that clean builds can be wildly different > > than incremental builds. > > One reason a policy has not been introduced for this before is that > producing a warning for the policy may be very verbose unless it is > delayed until variable dereference, but the latter would be a huge > performance hit to check. Still, I think things would be better off > in the long run with some policy for it. Like with some of the more disruptive policies (e.g., CMP0054), it's a clarification of some potentially^Wconfusing behavior which can bite you in certain cases pretty hard (CI vs. developer builds). > The "LOCAL_VARIABLES" change uses "SCOPE_VARIABLES" in some places. > The release note should only cover the new feature. Oops. Updated. Also reordered the branch so the feature is at the end of the branch. --Ben -- Powered by www.kitware.com Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Kitware offers various services to support the CMake community. For more information on each offering, please visit: CMake Support: http://cmake.org/cmake/help/support.html CMake Consulting: http://cmake.org/cmake/help/consulting.html CMake Training Courses: http://cmake.org/cmake/help/training.html Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Follow this link to subscribe/unsubscribe: http://public.kitware.com/mailman/listinfo/cmake-developers
