[cmake-developers] [CMake 0015375]: Please provide a way to evaluate generator expressions on demand

[Mantis Bug Tracker]

The following issue has been SUBMITTED. 
====================================================================== 
http://public.kitware.com/Bug/view.php?id=15375 
====================================================================== 
Reported By:                raspy
Assigned To:                
====================================================================== 
Project:                    CMake
Issue ID:                   15375
Category:                   CMake
Reproducibility:            have not tried
Severity:                   feature
Priority:                   normal
Status:                     new
====================================================================== 
Date Submitted:             2015-01-27 11:00 EST
Last Modified:              2015-01-27 11:00 EST
====================================================================== 
Summary:                    Please provide a way to evaluate generator
expressions on demand
Description: 
I have a use case like this:

I have a custom module which requires to call external script with current
compilation flags. This is performed with execute_process() passing flags
gathered from property COMPILE_OPTIONS, CMAKE_C_FLAGS and
CMAKE_C_FLAGS_${CMAKE_BUILD_TYPE}.

However, with the COMPILE_OPTIONS I get generator expression, which is not
evaluated, i.e. $<$<CONFIG:DEBUG>:-g> and passing it further makes no sense. It
would be good if I could in any way (with a variant of set() command maybe?)
force evaluation of such generator expressions to make use of them where they
may be needed but not natively supported.
====================================================================== 

Issue History 
Date Modified    Username       Field                    Change               
====================================================================== 
2015-01-27 11:00 raspy          New Issue                                    
======================================================================