From a820d385662d5725a13e3acfe35d00344be53532 Mon Sep 17 00:00:00 2001
From: Eero Aaltonen <eero.aaltonen@vaisala.com>
Date: Fri, 14 Oct 2022 17:38:42 +0300
Subject: [PATCH] Write CMake config-file package using helper

Write our CMake config-file package using the
`configure_package_config_file` function defined in
CMakePackageConfigHelpers.cmake
and export our library in a namespace so that it can be used as an
imported target.
---
 CMakeLists.txt                                | 16 +++++++++++++---
 docopt-config.cmake => docopt-config.cmake.in |  4 ++++
 2 files changed, 17 insertions(+), 3 deletions(-)
 rename docopt-config.cmake => docopt-config.cmake.in (53%)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 28da614..da29dde 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -101,9 +101,19 @@ install(FILES ${docopt_HEADERS} DESTINATION include/docopt)
 
 # CMake Package
 include(CMakePackageConfigHelpers)
-write_basic_package_version_file("${PROJECT_BINARY_DIR}/docopt-config-version.cmake" COMPATIBILITY SameMajorVersion)
-install(FILES docopt-config.cmake ${PROJECT_BINARY_DIR}/docopt-config-version.cmake DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/docopt")
-install(EXPORT ${export_name} DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/docopt")
+set(ConfigPackageLocation "cmake/docopt")
+# Unix layout, ref https://cmake.org/cmake/help/latest/command/find_package.html#config-mode-search-procedure
+configure_package_config_file(docopt-config.cmake.in
+	"${CMAKE_CURRENT_BINARY_DIR}/${ConfigPackageLocation}/docopt-config.cmake"
+	INSTALL_DESTINATION "${CMAKE_INSTALL_LIBDIR}/${ConfigPackageLocation}")
+write_basic_package_version_file("${PROJECT_BINARY_DIR}/${ConfigPackageLocation}/docopt-config-version.cmake"
+	COMPATIBILITY SameMajorVersion)
+install(FILES "${CMAKE_CURRENT_BINARY_DIR}/${ConfigPackageLocation}/docopt-config.cmake"
+	${PROJECT_BINARY_DIR}/${ConfigPackageLocation}/docopt-config-version.cmake
+	DESTINATION "${CMAKE_INSTALL_LIBDIR}/${ConfigPackageLocation}")
+install(EXPORT ${export_name}
+	DESTINATION "${CMAKE_INSTALL_LIBDIR}/${ConfigPackageLocation}"
+	NAMESPACE Docopt::)
 
 configure_file(${CMAKE_CURRENT_SOURCE_DIR}/docopt.pc.in ${CMAKE_CURRENT_BINARY_DIR}/docopt.pc @ONLY)
 install(FILES ${CMAKE_CURRENT_BINARY_DIR}/docopt.pc DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig)
diff --git a/docopt-config.cmake b/docopt-config.cmake.in
similarity index 53%
rename from docopt-config.cmake
rename to docopt-config.cmake.in
index 33c36c0..1782482 100644
--- a/docopt-config.cmake
+++ b/docopt-config.cmake.in
@@ -1 +1,5 @@
+@PACKAGE_INIT@
+
 include("${CMAKE_CURRENT_LIST_DIR}/docopt-targets.cmake")
+
+check_required_components(docopt)