cmake: export an installable pdg package

CMakeLists.txt

@@ -1,6 +1,9 @@
 cmake_minimum_required(VERSION 3.16)
 project(pdg VERSION 0.1.0 LANGUAGES CXX)
 
+include(CMakePackageConfigHelpers)
+include(GNUInstallDirs)
+
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFF)
@@ -23,9 +26,10 @@ add_library(pdg STATIC
   src/mc.cpp
 )
 add_library(pdg::pdg ALIAS pdg)
+target_compile_features(pdg PUBLIC cxx_std_17)
 target_include_directories(pdg PUBLIC
   $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
-  $<INSTALL_INTERFACE:include>
+  $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>
 )
 
 if(PDG_WARNINGS)
@@ -46,6 +50,17 @@ if(PDG_BUILD_TESTS)
     target_link_libraries(test_${t} PRIVATE pdg)
     add_test(NAME ${t} COMMAND test_${t})
   endforeach()
+
+  add_test(NAME package-consumer
+    COMMAND ${CMAKE_COMMAND}
+      "-DPDG_BINARY_DIR=${CMAKE_BINARY_DIR}"
+      "-DPDG_SOURCE_DIR=${CMAKE_SOURCE_DIR}"
+      "-DPDG_BUILD_CONFIG=$<CONFIG>"
+      "-DPDG_GENERATOR=${CMAKE_GENERATOR}"
+      "-DPDG_GENERATOR_PLATFORM=${CMAKE_GENERATOR_PLATFORM}"
+      "-DPDG_GENERATOR_TOOLSET=${CMAKE_GENERATOR_TOOLSET}"
+      -P "${CMAKE_SOURCE_DIR}/cmake/test_package.cmake"
+  )
 endif()
 
 if(PDG_BUILD_EXAMPLES)
@@ -55,5 +70,35 @@ if(PDG_BUILD_EXAMPLES)
   endforeach()
 endif()
 
-install(TARGETS pdg EXPORT pdgTargets ARCHIVE DESTINATION lib)
-install(DIRECTORY include/pdg DESTINATION include)
+set(PDG_INSTALL_CMAKEDIR "${CMAKE_INSTALL_LIBDIR}/cmake/pdg")
+
+install(TARGETS pdg
+  EXPORT pdgTargets
+  ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+  LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+  RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+  INCLUDES DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+)
+install(DIRECTORY include/pdg DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
+
+configure_package_config_file(
+  cmake/pdgConfig.cmake.in
+  "${CMAKE_CURRENT_BINARY_DIR}/pdgConfig.cmake"
+  INSTALL_DESTINATION "${PDG_INSTALL_CMAKEDIR}"
+)
+write_basic_package_version_file(
+  "${CMAKE_CURRENT_BINARY_DIR}/pdgConfigVersion.cmake"
+  VERSION ${PROJECT_VERSION}
+  COMPATIBILITY SameMajorVersion
+)
+
+install(EXPORT pdgTargets
+  FILE pdgTargets.cmake
+  NAMESPACE pdg::
+  DESTINATION "${PDG_INSTALL_CMAKEDIR}"
+)
+install(FILES
+  "${CMAKE_CURRENT_BINARY_DIR}/pdgConfig.cmake"
+  "${CMAKE_CURRENT_BINARY_DIR}/pdgConfigVersion.cmake"
+  DESTINATION "${PDG_INSTALL_CMAKEDIR}"
+)

README.md

@@ -66,6 +66,20 @@ ctest --test-dir build
 
 C++17, CMake >= 3.16. Tested with GCC 13; CI also builds MSVC and clang.
 
+To install `pdg` and consume it from another CMake project:
+
+```bash
+cmake --install build --prefix /path/to/pdg-install
+```
+
+```cmake
+find_package(pdg CONFIG REQUIRED)
+target_link_libraries(my_app PRIVATE pdg::pdg)
+```
+
+Pass the install prefix through `CMAKE_PREFIX_PATH` when configuring the
+consumer project if it is outside CMake's standard search locations.
+
 ## Usage
 
 3-DoF, classic Mars descent numbers:

cmake/pdgConfig.cmake.in

@@ -0,0 +1,8 @@
+@PACKAGE_INIT@
+
+include(CMakeFindDependencyMacro)
+find_dependency(Threads)
+
+include("${CMAKE_CURRENT_LIST_DIR}/pdgTargets.cmake")
+
+check_required_components(pdg)

cmake/test_package.cmake

@@ -0,0 +1,65 @@
+cmake_minimum_required(VERSION 3.16)
+
+foreach(required_var PDG_BINARY_DIR PDG_SOURCE_DIR PDG_BUILD_CONFIG PDG_GENERATOR)
+  if(NOT DEFINED ${required_var} OR "${${required_var}}" STREQUAL "")
+    message(FATAL_ERROR "${required_var} is required")
+  endif()
+endforeach()
+
+set(test_root "${PDG_BINARY_DIR}/package-test")
+set(install_dir "${test_root}/install")
+set(consumer_build_dir "${test_root}/consumer-build")
+file(REMOVE_RECURSE "${test_root}")
+
+execute_process(
+  COMMAND "${CMAKE_COMMAND}" --install "${PDG_BINARY_DIR}"
+          --prefix "${install_dir}" --config "${PDG_BUILD_CONFIG}"
+  RESULT_VARIABLE install_result
+  COMMAND_ECHO STDOUT
+)
+if(NOT install_result EQUAL 0)
+  message(FATAL_ERROR "pdg installation failed with exit code ${install_result}")
+endif()
+
+set(configure_args
+  -S "${PDG_SOURCE_DIR}/tests/package_consumer"
+  -B "${consumer_build_dir}"
+  -G "${PDG_GENERATOR}"
+  "-DCMAKE_BUILD_TYPE=${PDG_BUILD_CONFIG}"
+  "-DCMAKE_PREFIX_PATH=${install_dir}"
+)
+if(DEFINED PDG_GENERATOR_PLATFORM AND NOT "${PDG_GENERATOR_PLATFORM}" STREQUAL "")
+  list(APPEND configure_args -A "${PDG_GENERATOR_PLATFORM}")
+endif()
+if(DEFINED PDG_GENERATOR_TOOLSET AND NOT "${PDG_GENERATOR_TOOLSET}" STREQUAL "")
+  list(APPEND configure_args -T "${PDG_GENERATOR_TOOLSET}")
+endif()
+
+execute_process(
+  COMMAND "${CMAKE_COMMAND}" ${configure_args}
+  RESULT_VARIABLE configure_result
+  COMMAND_ECHO STDOUT
+)
+if(NOT configure_result EQUAL 0)
+  message(FATAL_ERROR "consumer configuration failed with exit code ${configure_result}")
+endif()
+
+execute_process(
+  COMMAND "${CMAKE_COMMAND}" --build "${consumer_build_dir}"
+          --config "${PDG_BUILD_CONFIG}"
+  RESULT_VARIABLE build_result
+  COMMAND_ECHO STDOUT
+)
+if(NOT build_result EQUAL 0)
+  message(FATAL_ERROR "consumer build failed with exit code ${build_result}")
+endif()
+
+execute_process(
+  COMMAND "${CMAKE_CTEST_COMMAND}" -C "${PDG_BUILD_CONFIG}" --output-on-failure
+  WORKING_DIRECTORY "${consumer_build_dir}"
+  RESULT_VARIABLE test_result
+  COMMAND_ECHO STDOUT
+)
+if(NOT test_result EQUAL 0)
+  message(FATAL_ERROR "consumer test failed with exit code ${test_result}")
+endif()

tests/package_consumer/CMakeLists.txt

@@ -0,0 +1,11 @@
+cmake_minimum_required(VERSION 3.16)
+project(pdg_package_consumer LANGUAGES CXX)
+
+enable_testing()
+
+find_package(pdg 0.1 CONFIG REQUIRED)
+
+add_executable(pdg_package_consumer main.cpp)
+target_link_libraries(pdg_package_consumer PRIVATE pdg::pdg)
+
+add_test(NAME pdg-package-consumer COMMAND pdg_package_consumer)

tests/package_consumer/main.cpp

@@ -0,0 +1,9 @@
+#include <pdg/linalg.hpp>
+
+#include <cmath>
+
+int main()
+{
+    const double values[] = {3.0, 4.0};
+    return std::abs(pdg::norm2(values, 2) - 5.0) < 1e-12 ? 0 : 1;
+}