Modernize dependency handling

Author: tipf

CMakeLists.txt

@@ -23,7 +23,7 @@
 # configure project
 ##################################
 
-cmake_minimum_required(VERSION 3.8)
+cmake_minimum_required(VERSION 3.20)
 
 project(libRSF VERSION "2.0.0" LANGUAGES CXX)
 
@@ -43,10 +43,10 @@ option(LIBRSF_BUILD_TEST "If enabled, the tests get build." OFF)
 ##################################
 
 # path for custom find scripts
-set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${CMAKE_SOURCE_DIR}/cmake)
+list(APPEND CMAKE_MODULE_PATH ${CMAKE_SOURCE_DIR}/cmake)
 
 # path for locally installed dependencies
-set(CMAKE_PREFIX_PATH ${CMAKE_PREFIX_PATH} ${CMAKE_SOURCE_DIR}/externals/install)
+list(APPEND CMAKE_PREFIX_PATH ${CMAKE_SOURCE_DIR}/externals/install)
 
 # Eigen for vectorized calculations
 find_package(Eigen3 3.3.5 REQUIRED NO_MODULE)

cmake/FindGeographicLib.cmake

@@ -10,32 +10,61 @@ find_library (GeographicLib_LIBRARIES
   NAMES GeographicLib Geographic
   PATHS "${CMAKE_INSTALL_PREFIX}/../GeographicLib/lib")
 
+find_path (GeographicLib_INCLUDE_DIRS
+  NAMES GeographicLib/Config.h
+  PATHS
+    "${CMAKE_INSTALL_PREFIX}/../GeographicLib/include"
+    "${CMAKE_INSTALL_PREFIX}/include")
+
+unset (GeographicLib_LIBRARY_DIRS)
 if (GeographicLib_LIBRARIES)
   get_filename_component (GeographicLib_LIBRARY_DIRS
     "${GeographicLib_LIBRARIES}" PATH)
-  get_filename_component (_ROOT_DIR "${GeographicLib_LIBRARY_DIRS}" PATH)
-  set (GeographicLib_INCLUDE_DIRS "${_ROOT_DIR}/include")
-  set (GeographicLib_BINARY_DIRS "${_ROOT_DIR}/bin")
-  if (NOT EXISTS "${GeographicLib_INCLUDE_DIRS}/GeographicLib/Config.h")
-    # On Debian systems the library is in e.g.,
-    #   /usr/lib/x86_64-linux-gnu/libGeographic.so
-    # so try stripping another element off _ROOT_DIR
-    get_filename_component (_ROOT_DIR "${_ROOT_DIR}" PATH)
-    set (GeographicLib_INCLUDE_DIRS "${_ROOT_DIR}/include")
-    set (GeographicLib_BINARY_DIRS "${_ROOT_DIR}/bin")
-    if (NOT EXISTS "${GeographicLib_INCLUDE_DIRS}/GeographicLib/Config.h")
-      unset (GeographicLib_INCLUDE_DIRS)
-      unset (GeographicLib_LIBRARIES)
-      unset (GeographicLib_LIBRARY_DIRS)
-      unset (GeographicLib_BINARY_DIRS)
-    endif ()
+endif ()
+
+unset (GeographicLib_BINARY_DIRS)
+if (GeographicLib_INCLUDE_DIRS)
+  get_filename_component (_GeographicLib_PREFIX "${GeographicLib_INCLUDE_DIRS}" PATH)
+  if (EXISTS "${_GeographicLib_PREFIX}/bin")
+    set (GeographicLib_BINARY_DIRS "${_GeographicLib_PREFIX}/bin")
   endif ()
-  unset (_ROOT_DIR)
+  unset (_GeographicLib_PREFIX)
+endif ()
+
+if (NOT GeographicLib_BINARY_DIRS)
+  find_program (_GeographicLib_TOOL
+    NAMES GeodSolve GeoConvert)
+  if (_GeographicLib_TOOL)
+    get_filename_component (GeographicLib_BINARY_DIRS "${_GeographicLib_TOOL}" PATH)
+  endif ()
+  unset (_GeographicLib_TOOL CACHE)
+  unset (_GeographicLib_TOOL)
 endif ()
 
 include (FindPackageHandleStandardArgs)
 find_package_handle_standard_args (GeographicLib DEFAULT_MSG
   GeographicLib_LIBRARY_DIRS GeographicLib_LIBRARIES
   GeographicLib_INCLUDE_DIRS)
+
+if(GeographicLib_FOUND)
+  set(GEOGRAPHICLIB_FOUND TRUE)
+endif()
+
+if(GeographicLib_FOUND AND NOT TARGET GeographicLib::GeographicLib)
+  # Determine the library type from the file extension so that target
+  # introspection (get_target_property TYPE) returns the correct value.
+  if(GeographicLib_LIBRARIES MATCHES "\\.a$")
+    set(_geographiclib_lib_type STATIC)
+  else()
+    set(_geographiclib_lib_type SHARED)
+  endif()
+  add_library(GeographicLib::GeographicLib ${_geographiclib_lib_type} IMPORTED)
+  set_target_properties(GeographicLib::GeographicLib PROPERTIES
+    IMPORTED_LOCATION "${GeographicLib_LIBRARIES}"
+    INTERFACE_INCLUDE_DIRECTORIES "${GeographicLib_INCLUDE_DIRS}"
+  )
+  unset(_geographiclib_lib_type)
+endif()
+
 mark_as_advanced (GeographicLib_LIBRARY_DIRS GeographicLib_LIBRARIES
   GeographicLib_INCLUDE_DIRS)

cmake/libRSFConfig.cmake.in

@@ -23,10 +23,10 @@ include(CMakeFindDependencyMacro)
 
 list(APPEND CMAKE_MODULE_PATH ${libRSF_CMAKE_DIR})
 
-find_package(Ceres 2.0 REQUIRED)
-find_package(Eigen3 3.3.5 REQUIRED)
-find_package(yaml-cpp REQUIRED)
-find_package(GeographicLib REQUIRED)
+find_dependency(Ceres 2.0 REQUIRED)
+find_dependency(Eigen3 3.3.5 REQUIRED NO_MODULE)
+find_dependency(yaml-cpp REQUIRED)
+find_dependency(GeographicLib REQUIRED)
 
 list(REMOVE_AT CMAKE_MODULE_PATH -1)
 

src/CMakeLists.txt

@@ -91,9 +91,14 @@ add_library(libRSF STATIC ${SOURCEFILES} ${HEADERFILES})
 # require at least C++ 17
 target_compile_features(libRSF PUBLIC cxx_std_17)
 
+set(LIBRSF_YAML_TARGET yaml-cpp::yaml-cpp)
+if(NOT TARGET yaml-cpp::yaml-cpp)
+  set(LIBRSF_YAML_TARGET yaml-cpp)
+endif()
+
 # to allow shared libraries to link against static libRSF
 set_target_properties(libRSF PROPERTIES POSITION_INDEPENDENT_CODE ON
-                                        CMAKE_CXX_EXTENSIONS OFF)
+                                        CXX_EXTENSIONS OFF)
 
 # set include dir of library depending on current tree (build/install)
 target_include_directories(libRSF
@@ -105,7 +110,7 @@ target_include_directories(libRSF
 )
 
 # set target (libRSF) dependencies
-target_link_libraries(libRSF PUBLIC Threads::Threads Eigen3::Eigen Ceres::ceres yaml-cpp ${GeographicLib_LIBRARIES})
+target_link_libraries(libRSF PUBLIC Threads::Threads Eigen3::Eigen Ceres::ceres ${LIBRSF_YAML_TARGET} GeographicLib::GeographicLib)
 
 # enable all warnings for libRSF (this is just enabled from time to time to check the code quality)
 #target_compile_options(libRSF PUBLIC -Wextra -Wpedantic -Wall -fmax-errors=100 -Wno-unused-parameter)