build: + cmake boilerplate to make indentlog cmake-findable

CMakeLists.txt

@@ -1,13 +1,13 @@
 cmake_minimum_required(VERSION 3.10)
 
-project(nestlog VERSION 0.1)
+project(indentlog VERSION 0.1)
 enable_language(CXX)
 
 include(cmake/nestlog.cmake)
 include(cmake/code-coverage.cmake)
 
 enable_testing()
-# activate code coverage for all executables + libraries (when -DCODE_COVERAGE=ON ??)
+# activate code coverage for all executables + libraries (when -DCODE_COVERAGE=ON)
 add_code_coverage()
 
 # 1. assuming that /nix/store/ prefixes .hpp files belonging to gcc, catch2 etc.
@@ -27,6 +27,9 @@ if(NOT USER)
     set(USER $ENV{USER})
 endif()
 
+# hmm. this works if explicitly given with cmake:
+#    cmake -DCMAKE_INSTALL_PREFIX=/home/roland/local path/to/source
+# but not as default
 if(NOT CMAKE_INSTALL_PREFIX)
     set(CMAKE_INSTALL_PREFIX /home/${USER}/local CACHE STRING "install directory")
 endif()
@@ -37,16 +40,44 @@ endif()
 add_subdirectory(example)
 add_subdirectory(utest)
 
-# header-only library
-#add_library(indentlog INTERFACE)
-#target_include_directories(indentlog INTERFACE
-#  $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>
-#  $<INSTALL_INTERFACE:include>
-#  )
+# header-only library.
+# see [[https://stackoverflow.com/questions/47718485/install-and-export-interface-only-library-cmake]]
 #
-#install(TARGETS indentlog
-#  PUBLIC_HEADER DESTINATION include)  # COMPONENT Development
+add_library(indentlog INTERFACE)
+target_include_directories(indentlog INTERFACE
+  $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>
+  $<INSTALL_INTERFACE:include>
+  )
 
+include(CMakePackageConfigHelpers)
+write_basic_package_version_file("${PROJECT_BINARY_DIR}/indentlogConfigVersion.cmake"
+    VERSION 0.1
+    COMPATIBILITY AnyNewerVersion
+)
+
+install(
+    TARGETS indentlog
+    EXPORT indentlogTargets
+    LIBRARY DESTINATION lib COMPONENT Runtime
+    ARCHIVE DESTINATION lib COMPONENT Development
+    RUNTIME DESTINATION bin COMPONENT Runtime
+    PUBLIC_HEADER DESTINATION include COMPONENT Development
+    BUNDLE DESTINATION bin COMPONENT Runtime
+    )
+
+include(CMakePackageConfigHelpers)
+configure_package_config_file(
+    "${PROJECT_SOURCE_DIR}/cmake/indentlogConfig.cmake.in"
+    "${PROJECT_BINARY_DIR}/indentlogConfig.cmake"
+    INSTALL_DESTINATION lib/cmake/indentlog
+    )
+
+install(EXPORT indentlogTargets DESTINATION lib/cmake/indentlog)
+install(
+    FILES
+    "${PROJECT_BINARY_DIR}/indentlogConfigVersion.cmake"
+    "${PROJECT_BINARY_DIR}/indentlogConfig.cmake"
+    DESTINATION lib/cmake/indentlog)
 install(DIRECTORY ${PROJECT_SOURCE_DIR}/include/ DESTINATION include)
 
 install(TARGETS hello DESTINATION bin/indentlog/example)

cmake/indentlogConfig.cmake.in

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