add lapack/blas wrapper as suggested in #3623 (#3757)

CMakeLists.txt

@@ -393,19 +393,9 @@ if(MKLROOT)
     list(APPEND math_libs -lifcore)
   endif()
 else()
-  # In compatibility to builtin FindLAPACK.cmake before v3.5.4
-  if(DEFINED LAPACK_DIR)
-    string(APPEND CMAKE_PREFIX_PATH ";${LAPACK_DIR}")
-  endif()
-  if(DEFINED LAPACK_LIBRARY)
-    set(LAPACK_LIBRARIES ${LAPACK_LIBRARY})
-  endif()
-  if(DEFINED BLAS_DIR)
-    string(APPEND CMAKE_PREFIX_PATH ";${BLAS_DIR}")
-  endif()
 
   find_package(FFTW3 REQUIRED)
-  find_package(LAPACK REQUIRED)
+  find_package(Lapack REQUIRED)
   include_directories(${FFTW3_INCLUDE_DIRS})
   list(APPEND math_libs FFTW3::FFTW3 LAPACK::LAPACK BLAS::BLAS)
 

cmake/FindBlas.cmake

@@ -0,0 +1,15 @@
+if(DEFINED BLAS_DIR)
+    string(APPEND CMAKE_PREFIX_PATH ";${BLAS_DIR}")
+endif()
+if(DEFINED BLAS_LIBRARY)
+    set(BLAS_LIBRARIES ${BLAS_LIBRARY})
+endif()
+
+find_package(BLAS REQUIRED)
+
+if(NOT TARGET BLAS::BLAS)
+    add_library(BLAS::BLAS UNKNOWN IMPORTED)
+    set_target_properties(BLAS::BLAS PROPERTIES
+        IMPORTED_LINK_INTERFACE_LANGUAGES "C"
+	IMPORTED_LOCATION "${BLAS_LIBRARIES}")
+endif()

cmake/FindLapack.cmake

@@ -0,0 +1,17 @@
+# In compatibility to builtin FindLAPACK.cmake before v3.5.4
+if(DEFINED LAPACK_DIR)
+  string(APPEND CMAKE_PREFIX_PATH ";${LAPACK_DIR}")
+endif()
+if(DEFINED LAPACK_LIBRARY)
+  set(LAPACK_LIBRARIES ${LAPACK_LIBRARY})
+endif()
+
+find_package(Blas REQUIRED)
+find_package(LAPACK REQUIRED)
+
+if(NOT TARGET LAPACK::LAPACK)
+    add_library(LAPACK::LAPACK UNKNOWN IMPORTED)
+    set_target_properties(LAPACK::LAPACK PROPERTIES
+        IMPORTED_LINK_INTERFACE_LANGUAGES "C"
+        IMPORTED_LOCATION "${LAPACK_LIBRARIES}")
+endif()