[CMake] CMAKE_CONFIGURATION_TYPES -- still in use? How to use?

[Brad King]

Zachary Pincus wrote:
> Let me recap to make sure I've got it:
> 
> *Configure time* operations (e.g. WRITE_FILE, say) must place  
> configuration-specific build files in every location specified by  
> CMAKE_CONFIGURATION_TYPES, because the build-time config is unknown,  or 
> may change.

CMAKE_CONFIGURATION_TYPES is set for generators that support multiple 
configuration types (and have per-configuration subdirectories like 
Debug and Release).  It is empty for other generators and for those 
generators the build type is controlled at CMake time by CMAKE_BUILD_TYPE.

> *Build time* operations must use the CMAKE_CFG_INTDIR variable to  
> select a file from the current build directory. This variable expands  
> to something like $(config) which is intelligible to the IDE running  
> the build.
> 
> *Install time* operations must use the BUILD_TYPE variable  (carefully, 
> so it isn't expanded until install time) which contains  the proper 
> build path. Since install is managed by cmake, and not  some IDE, the 
> CMAKE_CFG_INTDIR variable isn't useful because "$ (config)" or similar 
> is meaningless to cmake.
> 
> Is this all correct (if vaguely confusing)?

Yes, and *Test time* operations should use the CTEST_CONFIGURATION_NAME 
variable which like BUILD_TYPE for installing needs to be written 
\${CTEST_CONFIGURATION_NAME} to prevent expansion at CMake time.

The reason the names are so different for each stage is historical.  We 
plan to create a less confusing solution eventually.

-Brad