[CMake] CMAKE_MFC_FLAG not working in functions

[Michael Hertling]

On 10/20/2011 08:44 PM, Robert Dailey wrote:
> On Thu, Oct 20, 2011 at 12:56 PM, Michael Hertling <mhertling at online.de>wrote:
> 
>> On 10/20/2011 06:59 PM, Robert Dailey wrote:
>>> Let me ask this,
>>>
>>> What would be the parent of a function located in the root CMakeLists
>> file
>>> but called from a subordinate CMakeLists file?
>>
>> It's the subordinate CMakeLists.txt file's parent, but what Michael
>> probably aims at is that some variables undergo a lazy evaluation,
>> i.e. when you say
>>
>> set( CMAKE_MFC_FLAG 2 )
>> add_executable( ... )
>>
>> in a function, and CMAKE_MFC_FLAG isn't evaluated till generation time,
>> the value "2" will be lost since it is limited to the function's scope.
>> See the following project for an example:
> 
> 
> Does this lazy evaluation also apply to variables set with PARENT_SCOPE? If
> so, that would explain why not even that helped.

If the variable is subject to lazy evaluation - not all variables are,
and I don't know if CMAKE_MFC_FLAG is - it doesn't matter how it has
received its final value at the concerned CMakeLists.txt's end, i.e.
if it has been set in the CMakeLists.txt immediately or in a function
using PARENT_SCOPE or in a subordinate CMakeLists.txt file entered by
ADD_SUBDIRECTORY(), also using PARENT_SCOPE; the latest value will be
in effect for the generation step.

BTW, I talked trash:

>>> What would be the parent of a function located in the root CMakeLists
>> file
>>> but called from a subordinate CMakeLists file?
>>
>> It's the subordinate CMakeLists.txt file's parent, [...]

This is not true, of course. A function called from a CMakeLists.txt
file opens up its own scope, and its parent scope is the one of the
calling CMakeLists.txt file, not the one of the latter's parent.
Sorry about the mistake.

If your issue still persists, could you come up with a minimal
but complete exemplary project for further investigation?

Regards,

Michael