Modernized CMake recipes and moved files around.

CMakeLists.txt

@@ -1,34 +1,53 @@
-cmake_minimum_required (VERSION 3.2)
+# Support version 3.6 and above, but use policy settings up to 3.14.
+# 3.6 is needed because of IMPORTED_TARGET in pkg_check_modules().
+cmake_minimum_required(VERSION 3.6...3.14)
+# Ranges are supported from 3.12, set policy to current for < 3.12.
+if(${CMAKE_VERSION} VERSION_LESS 3.12)
+  cmake_policy(VERSION ${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION})
+endif()
+
 project(identiconpp
   VERSION 0.6.1
   LANGUAGES CXX)
+# DESCRIPTION was introduced in version 3.9.
+if(NOT (${CMAKE_VERSION} VERSION_LESS 3.9))
+  set(PROJECT_DESCRIPTION
+    "Library to generate identicons for C++.")
+endif()
 
 option(WITH_TESTS "Enable Tests" NO)
+option(BUILD_SHARED_LIBS "Build shared libraries." YES)
 
 set(CMAKE_CXX_STANDARD 14)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFF)
 
-set(CMAKE_CXX_FLAGS_DEBUG
-  "${CMAKE_CXX_FLAGS_DEBUG} -Wall -Wextra -Wpedantic -ftrapv \
--fsanitize=undefined -g -Og -fno-omit-frame-pointer")
+set(DEBUG_CXXFLAGS
+  "-Wall"
+  "-Wextra"
+  "-Wpedantic"
+  "-ftrapv"
+  "-fsanitize=undefined"
+  "-g"
+  "-Og"
+  "-fno-omit-frame-pointer")
+set(DEBUG_LDFLAGS
+  "-fsanitize=undefined")
+add_compile_options("$<$<CONFIG:Debug>:${DEBUG_CXXFLAGS}>")
+# add_link_options was introduced in version 3.13.
+if(${CMAKE_VERSION} VERSION_LESS 3.13)
+  set(CMAKE_SHARED_LINKER_FLAGS_DEBUG "${DEBUG_LDFLAGS}")
+else()
+  add_link_options("$<$<CONFIG:Debug>:${DEBUG_LDFLAGS}>")
+endif()
 
 if(CMAKE_BUILD_TYPE STREQUAL "Debug")
   add_definitions(-DDEBUG=1)
 endif()
 
-include(GNUInstallDirs)
-
-install(FILES README.md DESTINATION ${CMAKE_INSTALL_DOCDIR})
-
 add_subdirectory(src)
-
-configure_file("${PROJECT_SOURCE_DIR}/${PROJECT_NAME}.pc.in"
-  "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}.pc" @ONLY)
-
-install(FILES
-  "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}.pc"
-  DESTINATION "${CMAKE_INSTALL_LIBDIR}/pkgconfig")
+add_subdirectory(cmake)
+add_subdirectory(pkg-config)
 
 if(WITH_TESTS)
   add_subdirectory(tests)

README.md

@@ -13,7 +13,7 @@ modifications.
 "6x4 identicon, ltr_symmetric, 10px padding")
 
 The example images above are generated using [example.cpp]
-(https://schlomp.space/tastytea/identiconpp/src/branch/master/example.cpp).
+(https://schlomp.space/tastytea/identiconpp/src/branch/master/examples/example.cpp).
 
 ## Features
 
@@ -77,7 +77,7 @@ key](https://tastytea.de/tastytea_autosign.asc).
 
 * C++ compiler (tested: [gcc](https://gcc.gnu.org/) 6/8/9,
   [clang](https://llvm.org/) 6)
-* [cmake](https://cmake.org/) (at least 3.2)
+* [cmake](https://cmake.org/) (at least 3.6)
 * [imagemagick](https://www.imagemagick.org/) (tested: 7.0 / 6.7)
 * Optional:
   * Tests: [Catch](https://github.com/catchorg/Catch2) (tested: 2.3 / 1.2)

cmake/CMakeLists.txt

@@ -0,0 +1,19 @@
+include(CMakePackageConfigHelpers)
+include(GNUInstallDirs)
+
+write_basic_package_version_file("${PROJECT_NAME}ConfigVersion.cmake"
+  VERSION ${PACKAGE_VERSION}
+  COMPATIBILITY ExactVersion)   # NOTE: Set to SameMajorVersion when stable.
+
+install(EXPORT ${PROJECT_NAME}Targets
+  FILE "${PROJECT_NAME}Targets.cmake"
+  NAMESPACE "${PROJECT_NAME}::"
+  DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME}")
+
+configure_file("${PROJECT_NAME}Config.cmake.in"
+  "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}Config.cmake" @ONLY)
+
+install(FILES
+  "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}Config.cmake"
+  "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}ConfigVersion.cmake"
+  DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME}")

cmake/identiconppConfig.cmake.in

@@ -0,0 +1,7 @@
+include(CMakeFindDependencyMacro)
+include(GNUInstallDirs)
+
+find_dependency(PkgConfig REQUIRED)
+pkg_check_modules(Magick++ REQUIRED IMPORTED_TARGET Magick++)
+
+include("${CMAKE_CURRENT_LIST_DIR}/@PROJECT_NAME@Targets.cmake")

examples/CMakeLists.txt

@@ -0,0 +1,4 @@
+# You need to install identiconpp first so that CMake can find it.
+find_package(identiconpp REQUIRED CONFIG)
+add_executable(example example.cpp)
+target_link_libraries(example PRIVATE identiconpp::identiconpp)

pkg-config/CMakeLists.txt

@@ -0,0 +1,7 @@
+include(GNUInstallDirs)
+
+configure_file("${PROJECT_NAME}.pc.in"
+  "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}.pc" @ONLY)
+
+install(FILES "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}.pc"
+  DESTINATION "${CMAKE_INSTALL_LIBDIR}/pkgconfig")

pkg-config/identiconpp.pc.in

@@ -5,7 +5,7 @@ libdir=${prefix}/@CMAKE_INSTALL_LIBDIR@
 includedir=${prefix}/@CMAKE_INSTALL_INCLUDEDIR@
 
 Name: ${name}
-Description: Library to generate identicons for C++.
+Description: @PROJECT_DESCRIPTION@
 Version: @PROJECT_VERSION@
 Libs: -L${libdir} -l${name}
 Cflags: -I${includedir}

src/CMakeLists.txt

@@ -1,18 +1,18 @@
+include(GNUInstallDirs)
+
 find_package(PkgConfig REQUIRED)
-pkg_check_modules(MAGICPP REQUIRED Magick++)
-
-include_directories(${MAGICPP_INCLUDE_DIRS})
-
-link_directories(${MAGICPP_LIBRARY_DIRS})
+pkg_check_modules(Magick++ REQUIRED IMPORTED_TARGET Magick++)
 
 file(GLOB sources *.cpp)
-add_library(${PROJECT_NAME} SHARED ${sources})
-target_link_libraries(${PROJECT_NAME} ${MAGICPP_LIBRARIES})
-target_compile_options(${PROJECT_NAME} PUBLIC ${MAGICPP_CFLAGS})
+add_library(${PROJECT_NAME} ${sources} ${PROJECT_NAME}.hpp)
+target_link_libraries(${PROJECT_NAME} PkgConfig::Magick++)
 set_target_properties(${PROJECT_NAME} PROPERTIES
   VERSION ${PROJECT_VERSION}
   SOVERSION ${${PROJECT_NAME}_VERSION_MAJOR})
 
-install(TARGETS ${PROJECT_NAME} DESTINATION ${CMAKE_INSTALL_LIBDIR})
-install(FILES ${CMAKE_PROJECT_NAME}.hpp
+install(TARGETS ${PROJECT_NAME}
+  EXPORT "${PROJECT_NAME}Targets"
+  LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+  ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR})
+install(FILES ${PROJECT_NAME}.hpp
   DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})