[CMake] Always compile source file in debug

[Belcourt, Kenneth]

On Sep 3, 2010, at 7:51 AM, Michael Hertling wrote:

> On 09/03/2010 01:07 PM, Eric Noulard wrote:
>> 2010/9/3 Belcourt, Kenneth <kbelco at sandia.gov>:
>>> Hi,
>>>
>>> Apologies if this has been answered before.  In an effort to ensure
>>> cross-platform consistent results, I need to force some (C++ and  
>>> Fortran)
>>> source files to always be built debug.  Is there any easy syntax  
>>> to do this?
>>>
>>> I build our libraries like this.
>>>
>>> SET(SRCS
>>> ${EXEC_DIR}/AfterStep.f90
>>> ${EXEC_DIR}/ArgCF_Connect.f90
>>> ${EXEC_DIR}/ArgCF_Solve.f90
>>> ...
>>> )
>>>
>>> ADD_LIBRARY(exec ${SRCS})
>>
>> You may set some specific flags on specific sources using something  
>> like
>>
>> set_source_files_properties(file1.f90 file2.f90
>>                                                  PROPERTIES
>> COMPILE_FLAGS ${CMAKE_FORTRAN_FLAGS_DEBUG})
>>
>> but as far as I understand this does not replace default compile  
>> flags but add
>> extra flags for those particular source files...
>
> If these specific source files are confined to certain targets you
> could also impose the COMPILE_FLAGS target property on the latters.
>
>> Now if your "to be compiled with debug options" files may be  
>> contained in
>> separate libraries, may be you can create a sub-project which  
>> contains those
>> and enforce thsi subproject to be "CMAKE_BUILD_TYPE=Debug".
>
> Alternatively, you can reset the CMAKE_<LANG>_FLAGS_<CONFIG> variables
> in the concerned CMakeLists.txt, e.g. for C like the following:
>
> GET_DIRECTORY_PROPERTY(VARS VARIABLES)
> FOREACH(i IN LISTS VARS)
>    IF(i MATCHES "^CMAKE_C_FLAGS_.*\$")
>        SET(${i} "")
>    ENDIF()
> ENDFOREACH()
> SET(CMAKE_C_FLAGS "-g -O0 -DDEBUG")  # Your debug flags.
>
> This should work also with multi-configuration generators for
> which CMAKE_BUILD_TYPE has no meaning, or you differentiate
> between CMAKE_CONFIGURATION_TYPES and CMAKE_BUILD_TYPE to
> find out the flags to be tweaked.
>
> As a last resort, you may modify the rule variables, e.g.
>
> STRING(REGEX REPLACE "<FLAGS>" "-g -O0 -DDEBUG"
>       CMAKE_C_COMPILE_OBJECT ${CMAKE_C_COMPILE_OBJECT})
>
> - again in the concerned CMakeLists.txt - to obtain full
> control over the flags seen by the compiler, but note [1].

Thanks to you both (Michael and Eric).  I'm now selectively de- 
optimizing using the aforementioned techniques.

I appreciate your help!

-- Noel