ATLAS-314 Support older Eigen versions (e.g. 3.2.0)

ecmwf · Oct 22, 2020 · e69c520 · e69c520
1 parent 91040ca
commit e69c520
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diff --git a/cmake/atlas-import.cmake.in b/cmake/atlas-import.cmake.in
@@ -23,8 +23,9 @@ if( atlas_HAVE_FORTRAN )
 endif()
 
 ## Eigen3
-if( atlas_HAVE_EIGEN )
-  find_dependency( Eigen3 HINTS @Eigen3_DIR@ )
+set( Eigen3_HINT @Eigen3_DIR@ )
+if( atlas_HAVE_EIGEN AND Eigen3_HINT )
+  find_dependency( Eigen3 HINTS ${Eigen3_HINT} )
 endif()
 
 ## gridtools_storage

diff --git a/cmake/features/EIGEN.cmake b/cmake/features/EIGEN.cmake
@@ -1,8 +1,12 @@
 ### Eigen
 
-set( Eigen3_NO_MODULE ON )
-ecbuild_find_package( NAME Eigen3 VERSION 3.3 QUIET )
 ecbuild_add_option( FEATURE EIGEN
                     DESCRIPTION "Use Eigen linear algebra library"
-                    CONDITION TARGET Eigen3::Eigen )
+                    REQUIRED_PACKAGES Eigen3 )
 
+if( HAVE_EIGEN AND NOT TARGET Eigen3::Eigen )
+    # This is the case for older Eigen versions (e.g. 3.2.0)
+    ecbuild_add_library( TARGET atlas_eigen3 TYPE INTERFACE )
+    target_include_directories( atlas_eigen3 INTERFACE ${EIGEN3_INCLUDE_DIRS} )
+    add_library( Eigen3::Eigen ALIAS atlas_eigen3 )
+endif()