Add GMP support via custom FindGMP module

Introduce a custom FindGMP.cmake module to locate and configure GMP library dependencies. This change streamlines GMP integration by handling both pkg-config and direct library searches, ensuring compatibility across different platforms and setups. The CMakeLists.txt is updated to use this new module for improved maintainability.

CMakeLists.txt

@@ -76,7 +76,14 @@ list(APPEND CMAKE_MODULE_PATH ${CMAKE_CURRENT_LIST_DIR}/cmake/Modules)
 # and text editors.
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 
+# Now we get to adding our components. Let's do some global setup such as
+# setting the CXX standard and the shared library details.
+set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
+# I don't think we have any pure C anywhere, but we set the standard anyway
+set(CMAKE_C_STANDARD 11)
+set(CMAKE_C_STANDARD_REQUIRED ON)
 
 
 # TODO: Handle these more delicately.
@@ -242,71 +249,15 @@ find_package(OpenCL CONFIG REQUIRED)
 find_package(pybind11 CONFIG REQUIRED)
 find_package(cereal CONFIG REQUIRED)
 find_package(PCGRandom REQUIRED)
+find_package(GMP REQUIRED)
 
 message(STATUS "Target architecture ${RPY_ARCH}")
 
 
-#find_package(PkgConfig REQUIRED)
-#pkg_check_modules(gmp REQUIRED IMPORTED_TARGET gmp)
-#add_library(Bignum::Bignum ALIAS PkgConfig::gmp)
-#set(Bignum_LIBRARY "$<TARGET_FILE:PkgConfig::gmp>")
-#set(Bignum_INCLUDE_DIR "$<TARGET_PROPERTY:PkgConfig::gmp,INTERFACE_INCLUDE_DIRECTORY>")
-
-
-#if (APPLE AND NOT DEFINED MKL_OMP_LIB)
-#    get_brew_prefix(_libomp_prefix libomp VERBOSE)
-#
-#    if (_libomp_prefix AND EXISTS ${_libomp_prefix})
-#        list(APPEND CMAKE_PREFIX_PATH ${_libomp_prefix})
-#    endif()
-#endif()
-#
-#find_package(OpenMP REQUIRED COMPONENTS CXX)
-
-#if (MSVC)
-#    # MSVC has openmp from the stone ages, so add the experimental flag
-#    get_target_property(_omp_flags OpenMP::OpenMP_CXX INTERFACE_COMPILE_OPTIONS)
-#    string(REPLACE "/openmp" "/openmp:experimental" _omp_flags "${_omp_flags}")
-#    set_target_properties(OpenMP::OpenMP_CXX PROPERTIES
-#            INTERFACE_COMPILE_OPTIONS "${_omp_flags}")
-#endif()
-
-
-#find_package(Libalgebra_lite REQUIRED)
-
-find_package(PkgConfig REQUIRED)
-pkg_check_modules(GMP QUIET IMPORTED_TARGET gmp)
-if (TARGET PkgConfig::GMP)
-    add_library(GMP::GMP ALIAS PkgConfig::GMP)
-elseif(DEFINED VCPKG_INSTALLED_DIR)
-    find_path(GMP_INCLUDES NAMES gmp.h
-    PATHS ${VCPKG_INSTALLED_DIR})
-
-    find_library(GMP_LIBRARIES gmp mpir PATHS ${VCPKG_INSTALLED_DIR})
-
-    message(STATUS "GMP HEADERS: ${GMP_INCLUDES}")
-    message(STATUS "GMP LIBRARIES: ${GMP_LIBRARIES}")
-    if(GMP_INCLUDES AND GMP_LIBRARIES)
-        add_library(GMP::GMP UNKNOWN IMPORTED GLOBAL)
-        target_include_directories(GMP::GMP INTERFACE ${GMP_INCLUDES})
-
-        set_target_properties(GMP::GMP PROPERTIES
-            IMPORTED_LOCATION "${GMP_LIBRARIES}"
-        )
 
 
-    else()
-        message(FATAL_ERROR "Could not locate gmp")
-    endif()
-else()
-    message(FATAL_ERROR "Could not locate gmp, no vcpkg")
-endif()
 
 
-# Now we get to adding our components. Let's do some global setup such as
-# setting the CXX standard and the shared library details.
-set(CMAKE_CXX_STANDARD 17)
-set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
 if (APPLE)
     set(CMAKE_MACOSX_RPATH ON)

cmake/Modules/FindGMP.cmake

@@ -0,0 +1,111 @@
+
+if (GMP_FOUND)
+    return()
+endif()
+
+include(FindPackageHandleStandardArgs)
+include(SelectLibraryConfigurations)
+
+find_package(PkgConfig QUIET)
+
+if (PkgConfig_FOUND)
+    pkg_check_modules(PC_GMP QUIET gmp)
+endif ()
+
+if (GMP_PKG_FOUND)
+    set(GMP_INCLUDE_DIR "${PC_GMP_INCLUDE_DIRS}")
+    set(GMP_LIBRARY_DIRS "${PC_GMP_LIBRARY_DIRS}")
+    set(GMP_LIBRARIES "${PC_GMP_LIBRARIES}")
+    set(GMP_COMPILE_OPTIONS ${PC_GMP_CFLAGS} ${PC_GMP_CFLAGS_OTHER})
+    set(GMP_LINK_OPTIONS ${PC_GMP_LDFLAGS} ${PC_GMP_LDFLAGS_OTHER})
+else()
+
+    set(_gmp_lib_names gmp libgmp mpir libmpir)
+
+    find_library(GMP_LIBRARY_RELEASE
+            NAMES ${_gmp_lib_names}
+            HINTS "${VCPKG_INSTALLED_DIR}"
+    )
+
+    if (WIN32)
+        # VCPKG installs debug libraries in ${VCPKG_INSTALLED_DIR}/debug on Windows
+        find_library(GMP_LIBRARY_DEBUG
+                NAMES ${_gmp_lib_names}
+                HINTS "${VCPKG_INSTALLED_DIR}/debug"
+        )
+    else()
+        foreach(_name IN ITEMS ${_gmp_lib_names})
+            list(APPEND _gmp_lib_names_debug "${_name}d")
+        endforeach()
+
+        # Almost surely, sensible platforms will have pkgconfig find the libraries
+        find_library(GMP_LIBRARY_DEBUG
+                NAMES ${_gmp_lib_names_debug}
+                HINTS "${VCPKG_INSTALLED_DIR}"
+        )
+    endif()
+
+    set(GMP_COMPILE_OPTIONS "")
+    set(GMP_LINK_OPTIONS "")
+
+    find_path(GMP_INCLUDE_DIR NAMES gmp.h HINTS "${VCPKG_INSTALLED_DIR}")
+
+
+    select_library_configurations(GMP)
+
+endif ()
+
+
+
+
+find_package_handle_standard_args(GMP
+        FOUND_VAR GMP_FOUND
+        REQUIRED_VARS
+            GMP_LIBRARY GMP_INCLUDE_DIR)
+
+mark_as_advanced(
+        GMP_INCLUDE_DIR
+        GMP_LIBRARIES
+        GMP_LIBRARY_DIRS
+        GMP_COMPILE_OPTIONS
+        GMP_LINK_OPTIONS
+)
+
+
+if (GMP_FOUND AND NOT TARGET GMP::GMP)
+    add_library(GMP::GMP UNKNOWN IMPORTED GLOBAL)
+    set_target_properties(GMP::GMP PROPERTIES
+            IMPORTED_LOCATION "${GMP_LIBRARY}"
+            INTERFACE_INCLUDE_DIRECTORIES "${GMP_INCLUDE_DIR}"
+            IMPORTED_IMPLIB "${GMP_LIBRARY_DIRS}"
+    )
+    if (GMP_COMPILE_OPTIONS)
+        set_target_properties(GMP::GMP PROPERTIES
+                INTERFACE_COMPILE_OPTIONS "${GMP_COMPILE_OPTIONS}"
+        )
+    endif()
+    if(GMP_LINK_OPTIONS)
+        set_target_properties(GMP::GMP PROPERTIES
+                INTERFACE_LINK_OPTIONS "${GMP_LINK_OPTIONS}"
+        )
+    endif()
+
+    if (GMP_LIBRARY_RELEASE)
+        set_property(TARGET GMP::GMP APPEND PROPERTY
+            IMPORTED_CONFIGURATIONS RELEASE
+        )
+        set_target_properties(GMP::GMP PROPERTIES
+                IMPORTED_LOCATION_RELEASE "${GMP_LIBRARY_RELEASE}"
+        )
+    endif()
+    if (GMP_LIBRARY_RELEASE)
+        set_property(TARGET GMP::GMP APPEND PROPERTY
+                IMPORTED_CONFIGURATIONS DEBUG
+        )
+        set_target_properties(GMP::GMP PROPERTIES
+                IMPORTED_LOCATION_DEBUG "${GMP_LIBRARY_DEBUG}"
+        )
+    endif()
+
+
+endif()