From 6a5a61dfddf87feb8a3a7a3118ff65cb43d8ffe0 Mon Sep 17 00:00:00 2001
From: Timo Heister <timo.heister@gmail.com>
Date: Mon, 6 Jan 2020 21:33:45 -0500
Subject: [PATCH] add compile check

---
 cmake/configure/configure_2_trilinos.cmake | 37 ++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/cmake/configure/configure_2_trilinos.cmake b/cmake/configure/configure_2_trilinos.cmake
index 6e01e9dbca..89359216e0 100644
--- a/cmake/configure/configure_2_trilinos.cmake
+++ b/cmake/configure/configure_2_trilinos.cmake
@@ -246,6 +246,43 @@ MACRO(FEATURE_TRILINOS_FIND_EXTERNAL var)
       ENDIF()
     ENDIF()
 
+    IF(DEAL_II_TRILINOS_WITH_MUELU)
+      #
+      # Check if MueLu is actually usable.
+      #
+      LIST(APPEND CMAKE_REQUIRED_INCLUDES ${Trilinos_INCLUDE_DIRS})
+      LIST(APPEND CMAKE_REQUIRED_INCLUDES ${MPI_CXX_INCLUDE_PATH})
+      ADD_FLAGS(CMAKE_REQUIRED_FLAGS "${DEAL_II_CXX_VERSION_FLAG}")
+
+      LIST(APPEND CMAKE_REQUIRED_LIBRARIES ${Trilinos_LIBRARIES} ${MPI_LIBRARIES})
+
+      CHECK_CXX_SOURCE_COMPILES(
+        "
+        #include <MueLu_CreateEpetraPreconditioner.hpp>
+        int
+        main()
+        {
+          Epetra_CrsMatrix *matrix;
+          const auto teuchos_wrapped_matrix = Teuchos::rcp(matrix, false);	
+          Teuchos::ParameterList parameters;
+          MueLu::CreateEpetraPreconditioner(teuchos_wrapped_matrix, parameters);
+          return 0;
+        }
+        "
+        TRILINOS_MUELU_IS_FUNCTIONAL
+        )
+
+      RESET_CMAKE_REQUIRED()
+
+      IF(NOT TRILINOS_MUELU_IS_FUNCTIONAL)
+        MESSAGE(
+          STATUS
+          "MueLu was found but is not usable through Epetra! Disabling MueLu support."
+          )
+        SET(DEAL_II_TRILINOS_WITH_MUELU OFF)
+      ENDIF()
+    ENDIF()
+
     IF(${DEAL_II_TRILINOS_WITH_SACADO})
       #
       # Look for Sacado_config.h - we'll query it to determine C++11 support:
-- 
2.39.5