[CMake] Questions related to PkgConfig

[Radu Serban]

Hi,

I have a couple of questions related to using pkg-config in CMake:

1) Using information returned by the macro pkg_check_module from 
FindPkgConfig.cmake

This should be straightforward but I just cannot get it to work. Say I 
create my own library "mylib" which depends on a module "cvodes" which comes 
with a cvodes.pc file. Adding pkg_check_modules(CVODES cvodes) in 
CMakelists.txt correctly extracts all the information from cvodes.pc and 
sets the variables:
  ===========================
  cvodes pkgconfig results:
  ===========================
  PKG_CONFIG_FOUND 1
  PKG_CONFIG_EXECUTABLE /usr/bin/pkg-config
  CVODES_FOUND 1
  CVODES_LIBRARIES sundials_cvodes;sundials_nvecserial;sundials_nvecparallel;m
  CVODES_LIBRARY_DIRS /home/radu/CODES/NREL/lib
  CVODES_LDFLAGS 
-L/home/radu/CODES/NREL/lib;-lsundials_cvodes;-lsundials_nvecserial;-lsundials_nvecparallel;-lm
  CVODES_LDFLAGS_OTHERS
  CVODES_INCLUDE_DIRS /home/radu/CODES/NREL/include
  CVODES_CFLAGS -I/home/radu/CODES/NREL/include
  CVODES_CFLAGS_OTHERS
  ============================
I then use include_directories(${CVODES_INCLUDE_DIRS}) and successfully 
build the library mylib.

But then I'd like to build an example which must be linked with mylib and 
all CVODES libraries and this is where I got stuck... How do I use the above 
information? I have
   ADD_EXECUTABLE(testS testS.c)
   TARGET_LINK_LIBRARIES(testS as2)
but how about the CVODES libraries?  What's the proper way of linking the 
target testS to these libraries? I tried unsuccessfully all sort of 
combinations using TARGET_LINK_LIBRARIES and SET_TARGET_PROPERTIES...


2) Creating a *.pc file for a project.

Suppose my project creates a library "mylib" which requires the BLAS 
library. Since I do not have a blas.pc file, I simply use some 
FindBLAS.cmake file which finds the BLAS library as /usr/lib/libblas.so. 
When I create mylib.pc I cannot use something like "Requires: blas" because 
there is no blas.pc so I need to add the BLAS libraries under the "Libs" 
keyword. Does CMake provide a way of generating the proper string to be 
added to "Libs:"?

Thanks,
--Radu