[CMake] Compilation failure req'd for successful test

[Walter E Brown]

Brad King wrote:
> Walter E Brown wrote:
> 
>> As part of a project's testing, we need to ensure that a compilation 
>> failure will correctly occur under specific circumstances.  In 
>> particular, we wish at ctest time:
>>
>>   - to compile (but not link) a specific program that we expect to 
>> fail compilation, then
>>
>>   - to capture the detailed output of that compilation into a file, 
>> and then
>>
>>   - to run some other program (perhaps a tool like grep or perhaps a 
>> custom script) that inspects that attempted compilation's output for 
>> certain characteristics of interest, and finally
>>
>>   - to indicate the success or failure of the test based on the 
>> results of such inspection.
>>
>> Alas, it is unclear to us how to set this up; neither the book nor the 
>> online help seem on point.  Can someone advise us, preferably with 
>> sample cmake/ctest code that we can use as a model?
> 
> 
> Currently there is no easy way to do this.  You may have to create a 
> program that drives this process itself and then add the program as the 
> test.  It can use "ctest --build-and-test ..." to drive the build and 
> then capture the exit code and output.  You can look at 
> CMake/Source/kwsys (and even copy the library) to get some nice 
> cross-platform process execution code to help achieve this.
> 
> In the long run this should be a ctest feature accessible through an 
> option like "--build-fail-compile".  Please add it as a feature request 
> here:
> 
> http://www.cmake.org/Bug
> 
> Thanks,
> -Brad


I sincerely appreciate the prompt reply, but this is a truly unfortunate 
state of affairs.  Since we are not cmake/ctest experts, we will likely 
be unable to make effective progress along the lines you suggest; it is 
alas not in our work schedule to divert development effort in this 
direction.

You are certainly welcome to refer to my original email as a feature 
request.  Since our need is urgent, we will need to look elsewhere, I'm 
afraid; the rather sparse available documentation seems to leave us few 
choices.

(Incidentally, you may enjoy knowing that my spell-checker seems rather 
desperate to have me rewrite "ctest" as "cutest"!)

Best wishes,

-- WEB