Install the library and a CMake package

CMakeLists.txt

@@ -56,11 +56,47 @@ endif()
 add_subdirectory(rust_wrapper)
 
 # Add other subdirectories
-add_subdirectory(examples)
+option(CLARABEL_BUILD_EXAMPLES "Build the examples of Clarabel.cpp" true)
+if(CLARABEL_BUILD_EXAMPLES)
+  add_subdirectory(examples)
+endif()
 
 # Add tests
 option(CLARABEL_BUILD_TESTS "Build the unit tests for Clarabel.cpp" false)
 if(CLARABEL_BUILD_TESTS)
   enable_testing()
   add_subdirectory(tests)
 endif()
+
+#----------------------------------------------
+# Installation
+#----------------------------------------------
+include(GNUInstallDirs)
+include(CMakePackageConfigHelpers)
+
+set(CLARABEL_INSTALL_CMAKEDIR "${CMAKE_INSTALL_LIBDIR}/cmake/Clarabel"
+    CACHE STRING "Installation directory of the CMake package files")
+
+install(DIRECTORY "${CLARABEL_ROOT_DIR}/include/"
+    DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}")
+
+if(WIN32)
+    install(FILES "${CLARABEL_C_OUTPUT_DIR}/clarabel_c.dll"
+        DESTINATION "${CMAKE_INSTALL_BINDIR}")
+endif()
+install(FILES "${LIBCLARABEL_C_SHARED_PATH}" "${LIBCLARABEL_C_STATIC_PATH}"
+    DESTINATION "${CMAKE_INSTALL_LIBDIR}")
+
+configure_package_config_file(
+    "${CLARABEL_ROOT_DIR}/cmake/ClarabelConfig.cmake.in"
+    "${CMAKE_CURRENT_BINARY_DIR}/ClarabelConfig.cmake"
+    INSTALL_DESTINATION "${CLARABEL_INSTALL_CMAKEDIR}"
+    PATH_VARS CMAKE_INSTALL_INCLUDEDIR CMAKE_INSTALL_LIBDIR CMAKE_INSTALL_BINDIR)
+write_basic_package_version_file(
+    "${CMAKE_CURRENT_BINARY_DIR}/ClarabelConfigVersion.cmake"
+    VERSION ${CLARABEL_PROJECT_VERSION}
+    COMPATIBILITY SameMinorVersion)
+install(FILES
+    "${CMAKE_CURRENT_BINARY_DIR}/ClarabelConfig.cmake"
+    "${CMAKE_CURRENT_BINARY_DIR}/ClarabelConfigVersion.cmake"
+    DESTINATION "${CLARABEL_INSTALL_CMAKEDIR}")

README.md

@@ -80,6 +80,23 @@ where `VCPKG_TOOLCHAIN_PATH` is the path to the vcpkg toolchain file.
 
 - For 32-bit platforms, use `x86-windows` instead of `x64-windows`.
 
+## Installing the solver
+
+```sh
+cmake .. -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=<prefix>
+cmake --build .
+cmake --install .
+```
+
+installs the headers, the shared and the static library and a CMake package, which another project uses with
+
+```cmake
+find_package(Clarabel CONFIG REQUIRED)
+target_link_libraries(my_target PRIVATE Clarabel::clarabel_c)  # or Clarabel::clarabel_c_static
+```
+
+The same two targets are available when Clarabel.cpp is added with `add_subdirectory`. The examples are not built with `-DCLARABEL_BUILD_EXAMPLES=OFF`.
+
 ## Optional solver features
 
 Clarabel.rs supports a variety of build options for semidefinite program (SDP) support, JSON file read/write, 3rd party linear solvers etc.  Feature options can be passed to cargo via CMake using `-DCLARABEL_CARGO_FEATURES = "feature1,feature2,..."`.

cmake/ClarabelConfig.cmake.in

@@ -0,0 +1,74 @@
+# CMake package of Clarabel.cpp, which defines the imported targets
+#
+#   Clarabel::clarabel_c         the shared library
+#   Clarabel::clarabel_c_static  the static library
+#
+# both with the C headers (clarabel.h) and the C++ ones (clarabel.hpp), the
+# latter needing Eigen.
+
+@PACKAGE_INIT@
+
+# before the dependencies, whose own package files redefine PACKAGE_PREFIX_DIR
+set(_clarabel_includedir "@PACKAGE_CMAKE_INSTALL_INCLUDEDIR@")
+set(_clarabel_libdir "@PACKAGE_CMAKE_INSTALL_LIBDIR@")
+set(_clarabel_bindir "@PACKAGE_CMAKE_INSTALL_BINDIR@")
+set(_clarabel_definitions "@CLARABEL_C_DEFINITIONS@")
+
+include(CMakeFindDependencyMacro)
+find_dependency(Threads)
+find_package(Eigen3 3.4 CONFIG QUIET)
+
+if(NOT TARGET Clarabel::clarabel_c)
+    add_library(Clarabel::clarabel_c SHARED IMPORTED)
+    if(WIN32)
+        set_target_properties(Clarabel::clarabel_c PROPERTIES
+            IMPORTED_LOCATION "${_clarabel_bindir}/clarabel_c.dll"
+            IMPORTED_IMPLIB "${_clarabel_libdir}/clarabel_c.dll.lib")
+    elseif(APPLE)
+        set_target_properties(Clarabel::clarabel_c PROPERTIES
+            IMPORTED_LOCATION "${_clarabel_libdir}/libclarabel_c.dylib")
+    else()
+        # the library has no SONAME, so that it is linked by name rather than
+        # by its path, which would otherwise be recorded in the executables
+        set_target_properties(Clarabel::clarabel_c PROPERTIES
+            IMPORTED_LOCATION "${_clarabel_libdir}/libclarabel_c.so"
+            IMPORTED_NO_SONAME TRUE)
+    endif()
+endif()
+
+if(NOT TARGET Clarabel::clarabel_c_static)
+    add_library(Clarabel::clarabel_c_static STATIC IMPORTED)
+    if(WIN32)
+        set_target_properties(Clarabel::clarabel_c_static PROPERTIES
+            IMPORTED_LOCATION "${_clarabel_libdir}/clarabel_c.lib")
+    else()
+        set_target_properties(Clarabel::clarabel_c_static PROPERTIES
+            IMPORTED_LOCATION "${_clarabel_libdir}/libclarabel_c.a")
+    endif()
+    # the system libraries needed by the Rust standard library
+    if(CMAKE_SYSTEM_NAME STREQUAL "Linux")
+        set_property(TARGET Clarabel::clarabel_c_static APPEND PROPERTY
+            INTERFACE_LINK_LIBRARIES Threads::Threads ${CMAKE_DL_LIBS} m rt util)
+    endif()
+endif()
+
+foreach(_clarabel_target Clarabel::clarabel_c Clarabel::clarabel_c_static)
+    set_property(TARGET ${_clarabel_target} APPEND PROPERTY
+        INTERFACE_INCLUDE_DIRECTORIES "${_clarabel_includedir}")
+    if(_clarabel_definitions)
+        set_property(TARGET ${_clarabel_target} APPEND PROPERTY
+            INTERFACE_COMPILE_DEFINITIONS ${_clarabel_definitions})
+    endif()
+    if(TARGET Eigen3::Eigen)
+        set_property(TARGET ${_clarabel_target} APPEND PROPERTY
+            INTERFACE_LINK_LIBRARIES Eigen3::Eigen)
+    endif()
+endforeach()
+
+unset(_clarabel_target)
+unset(_clarabel_includedir)
+unset(_clarabel_libdir)
+unset(_clarabel_bindir)
+unset(_clarabel_definitions)
+
+check_required_components(Clarabel)

rust_wrapper/CMakeLists.txt

@@ -18,6 +18,10 @@ endif()
 
 set(CLARABEL_C_OUTPUT_DIR ${clarabel_c_output_directory} PARENT_SCOPE)
 
+# The compile definitions of the enabled features, which are also given to
+# the targets of the installed package
+set(clarabel_c_definitions "")
+
 if(NOT DEFINED CLARABEL_CARGO_FEATURES)
     set(CLARABEL_CARGO_FEATURES "")
 endif()
@@ -111,35 +115,41 @@ if(CONFIG_SDP)
     # Define the FEATURE_SDP flag for all targets that link against clarabel_c
     target_compile_definitions(libclarabel_c_static INTERFACE FEATURE_SDP)
     target_compile_definitions(libclarabel_c_shared INTERFACE FEATURE_SDP)
+    list(APPEND clarabel_c_definitions FEATURE_SDP)
 endif()
 
 rust_feature_is_enabled("faer-sparse" CONFIG_FAER_SPARSE)
 if(CONFIG_FAER_SPARSE)
     target_compile_definitions(libclarabel_c_static INTERFACE FEATURE_FAER_SPARSE)
     target_compile_definitions(libclarabel_c_shared INTERFACE FEATURE_FAER_SPARSE)
+    list(APPEND clarabel_c_definitions FEATURE_FAER_SPARSE)
 endif()
 
 rust_feature_is_enabled("pardiso-mkl" CONFIG_PARDISO_MKL)
 if(CONFIG_PARDISO_MKL)
     target_compile_definitions(libclarabel_c_static INTERFACE FEATURE_PARDISO_MKL)
     target_compile_definitions(libclarabel_c_shared INTERFACE FEATURE_PARDISO_MKL)
+    list(APPEND clarabel_c_definitions FEATURE_PARDISO_MKL)
 endif()
 
 rust_feature_is_enabled("pardiso-panua" CONFIG_PARDISO_PANUA)
 if(CONFIG_PARDISO_PANUA)
     target_compile_definitions(libclarabel_c_static INTERFACE FEATURE_PARDISO_PANUA)
     target_compile_definitions(libclarabel_c_shared INTERFACE FEATURE_PARDISO_PANUA)
+    list(APPEND clarabel_c_definitions FEATURE_PARDISO_PANUA)
 endif()
 
 if(CONFIG_PARDISO_MKL OR CONFIG_PARDISO_PANUA)
     target_compile_definitions(libclarabel_c_static INTERFACE FEATURE_PARDISO_ANY)
     target_compile_definitions(libclarabel_c_shared INTERFACE FEATURE_PARDISO_ANY)
+    list(APPEND clarabel_c_definitions FEATURE_PARDISO_ANY)
 endif()
 
 rust_feature_is_enabled("serde" CONFIG_SERDE)
 if(CONFIG_SERDE)
     target_compile_definitions(libclarabel_c_static INTERFACE FEATURE_SERDE)
     target_compile_definitions(libclarabel_c_shared INTERFACE FEATURE_SERDE)
+    list(APPEND clarabel_c_definitions FEATURE_SERDE)
 endif()
 
 # replace each rust <feature> with clarabel/<feature> so that they pass through 
@@ -178,10 +188,14 @@ elseif(WIN32)
     set(LIBCLARABEL_C_STATIC_PATH "${clarabel_c_output_directory}/clarabel_c.lib")
 endif()
 
+set(LIBCLARABEL_C_SHARED_PATH "${LIBCLARABEL_C_SHARED_PATH}" PARENT_SCOPE)
+set(LIBCLARABEL_C_STATIC_PATH "${LIBCLARABEL_C_STATIC_PATH}" PARENT_SCOPE)
+set(CLARABEL_C_DEFINITIONS "${clarabel_c_definitions}" PARENT_SCOPE)
+
 
 # Add the cargo project as a custom target
 add_custom_target(
-    libclarabel_c
+    libclarabel_c ALL
     WORKING_DIRECTORY ${CLARABEL_ROOT_DIR}/rust_wrapper
     # Commands for building the Rust library
     COMMAND cargo build ${clarabel_c_build_flags}
@@ -202,8 +216,19 @@ add_custom_target(
 target_link_libraries(libclarabel_c_static INTERFACE ${LIBCLARABEL_C_STATIC_PATH})
 target_include_directories(libclarabel_c_static INTERFACE ${CLARABEL_ROOT_DIR}/include)
 add_dependencies(libclarabel_c_static libclarabel_c)
+# the system libraries needed by the Rust standard library
+if(CMAKE_SYSTEM_NAME STREQUAL "Linux")
+    find_package(Threads REQUIRED)
+    target_link_libraries(libclarabel_c_static INTERFACE
+        Threads::Threads ${CMAKE_DL_LIBS} m rt util)
+endif()
 
 # Shared library
 target_link_libraries(libclarabel_c_shared INTERFACE ${LIBCLARABEL_C_SHARED_PATH})
 target_include_directories(libclarabel_c_shared INTERFACE ${CLARABEL_ROOT_DIR}/include)
 add_dependencies(libclarabel_c_shared libclarabel_c)
+
+# The names of the targets of the installed package, also when Clarabel.cpp
+# is consumed via `add_subdirectory`
+add_library(Clarabel::clarabel_c ALIAS libclarabel_c_shared)
+add_library(Clarabel::clarabel_c_static ALIAS libclarabel_c_static)