[CMake] Fortran Module dependency inside a preprocessor conditional

[Brad King]

On 05/15/2013 04:10 PM, Mark Cianciosa wrote:
> I have a fortran code that I'm compiling twice to generate two libraries. There is a USE statement inside a preprocessor conditional. It looks like cmake is not picking up the dependency because of it. The code in question is
> 
>       SUBROUTINE calc_fbal(bsubu, bsubv)
>       ...
>       USE realspace, ONLY: wint, phip
> #ifdef _ANIMEC
>      1                    ,pperp, ppar, onembc, sigma_an,
>      2                     pp1, pp2, pp3
>       USE vforces, gsqrt => azmn_o
> #endif
> 
> When I try to compile this, I get an error
> 
> [ 39%] Building Fortran object VMEC2000/CMakeFiles/animec.dir/Sources/General/fbal.f.o
> /trunk/VMEC2000/Sources/General/fbal.f:22.72:
> 
>       USE vforces, gsqrt => azmn_o                                      
>                                                                         1
> Fatal Error: Can't open module file 'vforces.mod' for reading at (1): No such file or directory
> 
> I'm defining _ANIMEC using the line
> 
> set_target_properties (animec PROPERTIES COMPILE_FLAGS "${BUILD_FLAGS} -D_ANIMEC")
> 
> because I only what it defined for this specific target only. Is there a better way define _ANIMEC so that it correctly finds the dependency?

CMake's Fortran dependency scanning does do some basic preprocessing
for conditions like this but it does not look for definitions in the
COMPILE_FLAGS property.  Use the COMPILE_DEFINITIONS property instead:

 set_property(TARGET animec APPEND PROPERTY COMPILE_DEFINITIONS _ANIMEC)

-Brad