Install CMake config (#31)

Author: ruslo

CMakeLists.txt

@@ -56,4 +56,61 @@ set(DLPACK_MOCK_SRCS ${CMAKE_CURRENT_SOURCE_DIR}/contrib/mock_main.cc
                     ${CMAKE_CURRENT_SOURCE_DIR}/contrib/mock_c.c)
 add_executable(mock ${DLPACK_MOCK_SRCS})
 
+add_library(dlpack INTERFACE)
+add_library(${PROJECT_NAME}::dlpack ALIAS dlpack)
 
+# Installation (https://github.com/forexample/package-example) {
+
+# Introduce variables:
+# * CMAKE_INSTALL_LIBDIR
+# * CMAKE_INSTALL_BINDIR
+# * CMAKE_INSTALL_INCLUDEDIR
+include(GNUInstallDirs)
+
+set(config_install_dir "${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME}")
+set(generated_dir "${CMAKE_CURRENT_BINARY_DIR}/generated")
+set(version_config "${generated_dir}/${PROJECT_NAME}ConfigVersion.cmake")
+set(project_config "${generated_dir}/${PROJECT_NAME}Config.cmake")
+set(TARGETS_EXPORT_NAME "${PROJECT_NAME}Targets")
+set(namespace "${PROJECT_NAME}::")
+
+include(CMakePackageConfigHelpers)
+
+# Use:
+# * PROJECT_VERSION
+write_basic_package_version_file(
+    "${version_config}" COMPATIBILITY SameMajorVersion
+)
+
+# Use:
+#   * TARGETS_EXPORT_NAME
+#   * PROJECT_NAME
+configure_package_config_file(
+    "cmake/template/Config.cmake.in"
+    "${project_config}"
+    INSTALL_DESTINATION "${config_install_dir}"
+)
+
+install(
+    TARGETS dlpack
+    EXPORT "${TARGETS_EXPORT_NAME}"
+    INCLUDES DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}"
+)
+
+install(
+    DIRECTORY include/
+    DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}"
+)
+
+install(
+    FILES "${project_config}" "${version_config}"
+    DESTINATION "${config_install_dir}"
+)
+
+install(
+    EXPORT "${TARGETS_EXPORT_NAME}"
+    NAMESPACE "${namespace}"
+    DESTINATION "${config_install_dir}"
+)
+
+# }

cmake/template/Config.cmake.in

@@ -0,0 +1,4 @@
+@PACKAGE_INIT@
+
+include("${CMAKE_CURRENT_LIST_DIR}/@TARGETS_EXPORT_NAME@.cmake")
+check_required_components("@PROJECT_NAME@")