[CMake] Static Modules

[Michael Wild]

On 12. Mar, 2010, at 11:42 , Markus Raab wrote:

> Hello!
> 
> Michael Wild wrote:
>> IMHO it would be simpler and safer to have a function which collects all
>> the file names, adds them to a global property and then allows you to
>> compile a static library from that. E.g (completely untested):
> 
> Yeah, you are right, this approach sounds much better.
> 
> But there is still a small missing piece. Modules have at least one entry
> point (or symbol) which is the same, so that they can be loaded.
> 
> This is perfectly ok for modules, but raises a problem when you want to link
> them together statically.
> 
> Elektra has solved this issue by having defined:
> #ifdef ELEKTRA_STATIC
>        #define KDBEXPORT(module) KDB
> *libelektra_##module##_LTX_kdbBackendFactory(void)      
> #else
>        #define KDBEXPORT(module) KDB *kdbBackendFactory(void)
> #endif
> 
> and Modules use
> KDBEXPORT(modulename)
> {
>        return kdbBackendExport(BACKENDNAME, ...
> }
> 
> to export this symbol which changes for the module and static case.
> 
> 
> Which is the cmake way to solve this issue?
> 
> thank you
> Markus
> 
> 
> -- 
> http://www.markus-raab.org | I can't believe that life's so complex,
>                      -o)  | when I just want to sit here and watch you 
> Kernel 2.6.24-1-a      /\  | undress   
> on a x86_64           _\_v | 


For shared libraries, CMake defined <name>_EXPORTS automatically, so you could use that in a #ifndef. Alternatively, in MY_ADD_STATIC_MODULE you can do the following after the ADD_LIBRARY call:

set_target_properties(${name} PROPERTIES
   COMPILE_DEFINITIONS ${name}_STATIC)


HTH

Michael