[CMake] problem with CMake not including library's path (with pkg-config)

[Francesco Abbate]

Hi all,

I stumbled in a problem with CMake. Everything is working fine except
that, for two libraries that I locate with pkg-config, cmake does not
include during linking the library's path (-L<path>) which is given by
pkg-config.


Here an extract of the CMakeLists.txt:


[...]

include(FindPkgConfig)
pkg_search_module(AGG REQUIRED libagg)

[...]

target_link_libraries(libcanvas ${AGG_LIBRARIES})
target_include_directories(libcanvas PUBLIC
${PROJECT_SOURCE_DIR}/include ${AGG_INCLUDE_DIRS})
[...]

When I run pkg-config everything is correct:

> pkg-config --libs libagg
-Lc:/fra/local_msys64/lib -lagg -lm

One can notice that pkg-config provides a non-standard path for the library.

By inspecting CMakeCache.txt I found a trace of the library's path.
See below an extract:

AGG_CFLAGS:INTERNAL=-Ic:/fra/local_msys64/include/agg2
AGG_CFLAGS_I:INTERNAL=
AGG_CFLAGS_OTHER:INTERNAL=
AGG_FOUND:INTERNAL=1
AGG_INCLUDEDIR:INTERNAL=c:/fra/local_msys64/include/agg2
AGG_INCLUDE_DIRS:INTERNAL=c:/fra/local_msys64/include/agg2
AGG_LDFLAGS:INTERNAL=-Lc:/fra/local_msys64/lib;-lagg;-lm
AGG_LDFLAGS_OTHER:INTERNAL=
AGG_LIBDIR:INTERNAL=c:/fra/local_msys64/lib
AGG_LIBRARIES:INTERNAL=agg;m
AGG_LIBRARY_DIRS:INTERNAL=c:/fra/local_msys64/lib
AGG_LIBS:INTERNAL=
AGG_LIBS_L:INTERNAL=
AGG_LIBS_OTHER:INTERNAL=
AGG_LIBS_PATHS:INTERNAL=
AGG_PREFIX:INTERNAL=c:/fra/local_msys64
AGG_STATIC_CFLAGS:INTERNAL=-Ic:/fra/local_msys64/include/agg2
AGG_STATIC_CFLAGS_I:INTERNAL=
AGG_STATIC_CFLAGS_OTHER:INTERNAL=
AGG_STATIC_INCLUDE_DIRS:INTERNAL=c:/fra/local_msys64/include/agg2
AGG_STATIC_LDFLAGS:INTERNAL=-Lc:/fra/local_msys64/lib;-lagg;-lm
AGG_STATIC_LDFLAGS_OTHER:INTERNAL=
AGG_STATIC_LIBDIR:INTERNAL=
AGG_STATIC_LIBRARIES:INTERNAL=agg;m
AGG_STATIC_LIBRARY_DIRS:INTERNAL=c:/fra/local_msys64/lib
AGG_STATIC_LIBS:INTERNAL=
AGG_STATIC_LIBS_L:INTERNAL=
AGG_STATIC_LIBS_OTHER:INTERNAL=
AGG_STATIC_LIBS_PATHS:INTERNAL=
AGG_VERSION:INTERNAL=2.5.0
AGG_libagg_INCLUDEDIR:INTERNAL=
AGG_libagg_LIBDIR:INTERNAL=
AGG_libagg_PREFIX:INTERNAL=
AGG_libagg_VERSION:INTERNAL=

but in the Ninja build file the library's path is not given (below an extract):

----------
#############################################
# Link the executable tests\test-window.exe

build tests/test-window.exe: CXX_EXECUTABLE_LINKER__test-window tests/CMakeFiles
/test-window.dir/test-window.cpp.obj | win32/liblibcanvaswin32.a src/liblibcanva
s.a || src/liblibcanvas.a win32/liblibcanvaswin32.a
  LINK_LIBRARIES = win32/liblibcanvaswin32.a src/liblibcanvas.a -lagg
-lm -lfreetype -lkernel32 -luser32 -lgdi32 -lwinspool -lshell32
-lole32 -loleaut32 -luuid -lcomdlg32 -ladvapi32
------------

So the behavior of CMake looks wrong to me. Pkg-config is giving
explicitly a non-standard library path but CMake just decided to not
include it in the linker options.

To finish let me report that I'am using CMake 3.11.1 on a Windows
system using MSYS2.

I can also mention that a similar Meson build just works fine but this
is only to make you, CMake guys, jealous.

Ok, just kidding :-)

Thank you in advance for any help.

Kind regards
Francesco





-- 
Francesco