Added Fastor (#77)

* Added Fastor to `algebra-plugins`

CMakeLists.txt

@@ -45,6 +45,8 @@ option( ALGEBRA_PLUGINS_INCLUDE_SMATRIX
    "Include Smatrix types in Algebra Plugins" FALSE )
 option( ALGEBRA_PLUGINS_INCLUDE_VC
    "Include Vc types in Algebra Plugins" FALSE )
+option( ALGEBRA_PLUGINS_INCLUDE_FASTOR
+   "Include Fastor types in Algebra Plugins" FALSE )
 option( ALGEBRA_PLUGINS_INCLUDE_VECMEM
    "Include VecMem types in Algebra Plugins" FALSE )
 option( ALGEBRA_PLUGINS_BUILD_TESTING "Build the unit tests of Algebra Plugins"
@@ -139,6 +141,20 @@ if( ALGEBRA_PLUGINS_SETUP_VC )
    endif()
 endif()
 
+# Set up Fastor.
+option( ALGEBRA_PLUGINS_SETUP_FASTOR
+   "Set up the Fastor target(s) explicitly" FALSE )
+option( ALGEBRA_PLUGINS_USE_SYSTEM_FASTOR
+   "Pick up an existing installation of Fastor from the build environment"
+   TRUE )
+if( ALGEBRA_PLUGINS_SETUP_FASTOR )
+   if( ALGEBRA_PLUGINS_USE_SYSTEM_FASTOR )
+      find_package( Fastor 0.6.3 REQUIRED )
+   else()
+      add_subdirectory( extern/fastor )
+   endif()
+endif()
+
 # Undo the developer flag suppression.
 if( _unsetDevWarningFlag )
    unset( CMAKE_SUPPRESS_DEVELOPER_WARNINGS )

extern/fastor/CMakeLists.txt

@@ -0,0 +1,30 @@
+# Algebra plugins library, part of the ACTS project (R&D line)
+#
+# (c) 2022 CERN for the benefit of the ACTS project
+#
+# Mozilla Public License Version 2.0
+
+# CMake include(s).
+cmake_minimum_required( VERSION 3.11 )
+include( FetchContent )
+
+# Tell the user what's happening.
+message( STATUS "Building Fastor as part of the Algebra Plugins project" )
+
+# Declare where to get Fastor from.
+# We need to use this alternative syntax for FetchContent_Declare because the
+# latest release for Fastor does not have a CMakeLists.txt file.
+set( ALGEBRA_PLUGINS_FASTOR_SOURCE
+   "fastor;GIT_REPOSITORY;https://github.com/romeric/Fastor.git;GIT_TAG;6d7216f304d60d92b9b042566d4d6e94c65086a3"
+   CACHE STRING "Source for Fastor, when built as part of this project" )
+mark_as_advanced( ALGEBRA_PLUGINS_FASTOR_SOURCE )
+FetchContent_Declare( fastor ${ALGEBRA_PLUGINS_FASTOR_SOURCE} )
+
+# Options used in the build of Fastor.
+set(BUILD_TESTING OFF CACHE BOOL "Don't build the Fastor tests")
+add_compile_definitions(FASTOR_ENABLE_RUNTIME_CHECKS=0)
+
+# Get it into the current directory.
+FetchContent_Populate( fastor )
+add_subdirectory( "${fastor_SOURCE_DIR}" "${fastor_BINARY_DIR}"
+   EXCLUDE_FROM_ALL )

extern/fastor/README.md

@@ -0,0 +1,4 @@
+# Build Recipe for Fastor
+
+This directory holds a simple build recipe for the
+[Fastor](https://github.com/romeric/Fastor) project.