[cmake-developers] FindBacktrace.cmake

[Vadim Zhukov]

2013/7/23 Alexander Neundorf <neundorf at kde.org>:
> On Tuesday 09 July 2013, Brad King wrote:
>> On 07/08/2013 05:51 PM, Vadim Zhukov wrote:
>> > I'm not sure whether resetting CMAKE_REQUIRED_* is the desired
>> > behavior. The example in the CMakePushCheckState.cmake documentation
>> > tells the opposite, and I think that appending values have a point by
>> > adding some sort of a flexibility for writers of other CMake project
>> > files and other CMake modules. Also, I see the same logic (append
>> > instead of rewrite) is used in other CMake modules (in KDE at least,
>> > where CMakePushCheckState.cmake did came from).
>> >
>> > And if CMAKE_REQUIRED_* should be generally reset within module, then
>> > I propose adding a third macro in CMakePushCheckState.cmake, say,
>> > cmake_reset_check_state(), which will do this.
>> >
>> > I'm adding Alexander Neundorf to the thread to make things more clear,
>> > as he developed CMakePushCheckState.cmake module. Alexander, could
>> > you, please, explain the way CMakePushCheckState macros should be
>> > used?
>>
>> I would like Alex's opinion on this, but we must either use
>> CMAKE_REQUIRED_* to report the results (as you did originally)
>> or not use the caller's CMAKE_REQUIRED_* to perform the test.
>> Otherwise the results will not be consistent.
>>
>> We have never (intentionally) defined CMAKE_REQUIRED_* as the
>> input to a _find_ module before, only to _check_ macros.  The
>> check state stack module helps a project handle its own check
>> accumulation
>
> Yes, that was the intention.
> Adding a cmake_reset_check_state() sounds good.
>
>> and AFAIK is not meant as an API between a project
>> and CMake find modules.
>>
>> It looks like a few find modules already use check macros and
>> do not pay any attention to whether CMAKE_REQUIRED_* is defined.
>> These may also need to be cleaned up based on the results of this
>> discussion.
>
> I found it only in FindGIF.cmake right now. There the reset() could be used
> then.

Brad and Alexander,

With all input from you and after setting up local development repo, I
created and pushed two branches to stage:

1. add-cmake_reset_check_state, adding CMAKE_RESET_CHECK_STATE() macro
and optional resetting functionality in CMAKE_PUSH_CHECK_STATE():
http://cmake.org/gitweb?p=stage/cmake.git;a=shortlog;h=refs/heads/add-cmake_reset_check_state

2. find_backtrace, adding Modules/FindBacktrace.cmake:
http://cmake.org/gitweb?p=stage/cmake.git;a=shortlog;h=refs/heads/find_backtrace

Are they fine? I made them independent on each other, to make
CMakePushCheckState-related conversion as a separate thing later.

If I understand correctly, there should be zero fallout in the night
build, and after that, given there will be no blockers, I should merge
them into the "next" branch, right?

--
  WBR,
  Vadim Zhukov