From aea6229c95101dc3a04a1a6103ee5c22d6b6b068 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Markus=20M=C3=BCtzel?= <markus.muetzel@gmx.de>
Date: Thu, 19 Sep 2024 18:57:39 +0200
Subject: [PATCH] Make building with UMFPACK optional.

Add new CMake variable `WITH_UMFPACK` which can be used to build without
using any functions from the UMFPACK library.

The default for this new variable is `TRUE` so there is no difference in
the build configuration to before unless a user explicitly configure
with, e.g., `-DWITH_UMFPACK=OFF`.

This probably fixes the issue described in #578.
---
 CMakeLists.txt     | 62 ++++++++++++++++++++++++++--------------------
 fem/config.h.cmake |  2 +-
 2 files changed, 36 insertions(+), 28 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9908d346cf..8141e368ad 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -81,6 +81,7 @@ SET(WITH_MKL FALSE CACHE BOOL "Use Intel Math Kernel library")
 SET(WITH_Mumps FALSE CACHE BOOL "Use Mumps sparse direct solver")
 SET(WITH_Hypre FALSE CACHE BOOL "Use Hypre linear algebra library")
 SET(WITH_CHOLMOD FALSE CACHE BOOL "Use CHOLMOD linear algebra library")
+SET(WITH_UMFPACK TRUE CACHE BOOL "Use UMFPACK for LU factorization")
 SET(WITH_ELMERGUI FALSE CACHE BOOL "Include ElmerGUI")
 SET(WITH_ElmerIce FALSE CACHE BOOL "Include ElmerIce")
 SET(WITH_XIOS FALSE CACHE BOOL "Include XIOS")
@@ -629,29 +630,35 @@ IF(WITH_ElmerIce)
   ADD_SUBDIRECTORY(elmerice)
 ENDIF(WITH_ElmerIce)
 
-IF (EXTERNAL_UMFPACK)
-  MESSAGE(STATUS "Using external UMFPACK instead of built-in")
-  FIND_PACKAGE(UMFPACK REQUIRED)
-
-  # Check for size of "SuiteSparse_long"
-  INCLUDE(CheckTypeSize)
-  SET(old_CMAKE_REQUIRED_INCLUDES ${CMAKE_REQUIRED_INCLUDES})
-  SET(old_CMAKE_EXTRA_INCLUDE_FILES ${CMAKE_EXTRA_INCLUDE_FILES})
-  LIST(APPEND CMAKE_REQUIRED_INCLUDES "${UMFPACK_INCLUDE_DIR}")
-  LIST(APPEND CMAKE_EXTRA_INCLUDE_FILES "umfpack.h")
-  CHECK_TYPE_SIZE("SuiteSparse_long" SIZEOF_SUITESPARSE_LONG LANGUAGE C)
-  SET(CMAKE_REQUIRED_INCLUDES ${old_CMAKE_REQUIRED_INCLUDES})
-  SET(CMAKE_EXTRA_INCLUDE_FILES ${old_CMAKE_EXTRA_INCLUDE_FILES})
-  IF (HAVE_SIZEOF_SUITESPARSE_LONG)
-    IF (SIZEOF_SUITESPARSE_LONG EQUAL 4)
-      SET(UMFPACK_LONG_FORTRAN_TYPE "C_INT32_T")
-    ELSE()
-      SET(UMFPACK_LONG_FORTRAN_TYPE "C_INT64_T")
+IF (WITH_UMFPACK)
+  IF (EXTERNAL_UMFPACK)
+    MESSAGE(STATUS "Using external UMFPACK instead of built-in")
+    FIND_PACKAGE(UMFPACK REQUIRED)
+
+    # Check for size of "SuiteSparse_long"
+    INCLUDE(CheckTypeSize)
+    SET(old_CMAKE_REQUIRED_INCLUDES ${CMAKE_REQUIRED_INCLUDES})
+    SET(old_CMAKE_EXTRA_INCLUDE_FILES ${CMAKE_EXTRA_INCLUDE_FILES})
+    LIST(APPEND CMAKE_REQUIRED_INCLUDES "${UMFPACK_INCLUDE_DIR}")
+    LIST(APPEND CMAKE_EXTRA_INCLUDE_FILES "umfpack.h")
+    CHECK_TYPE_SIZE("SuiteSparse_long" SIZEOF_SUITESPARSE_LONG LANGUAGE C)
+    SET(CMAKE_REQUIRED_INCLUDES ${old_CMAKE_REQUIRED_INCLUDES})
+    SET(CMAKE_EXTRA_INCLUDE_FILES ${old_CMAKE_EXTRA_INCLUDE_FILES})
+    IF (HAVE_SIZEOF_SUITESPARSE_LONG)
+      IF (SIZEOF_SUITESPARSE_LONG EQUAL 4)
+        SET(UMFPACK_LONG_FORTRAN_TYPE "C_INT32_T")
+      ELSE()
+        SET(UMFPACK_LONG_FORTRAN_TYPE "C_INT64_T")
+      ENDIF()
     ENDIF()
+  ELSE()
+    MESSAGE(STATUS "Using built-in UMFPACK")
+    ADD_SUBDIRECTORY(umfpack)
   ENDIF()
+  SET(HAVE_UMFPACK ON)
+  MARK_AS_ADVANCED(HAVE_UMFPACK)
 ELSE()
-  MESSAGE(STATUS "Using built-in UMFPACK")
-  ADD_SUBDIRECTORY(umfpack)
+  MESSAGE(STATUS "Building without UMFPACK")
 ENDIF()
 IF(NOT DEFINED UMFPACK_LONG_FORTRAN_TYPE)
   # Old versions of UMFPACK before "SuiteSparse_long" was defined used "long"
@@ -711,13 +718,14 @@ MESSAGE(STATUS "------------------------------------------------")
 MESSAGE(STATUS "  BLAS library:   " "${BLAS_LIBRARIES}")
 MESSAGE(STATUS "  LAPACK library: " "${LAPACK_LIBRARIES}")
 MESSAGE(STATUS "------------------------------------------------")
-IF(UMFPACK_FOUND)
-  MESSAGE(STATUS " UMFPACK library: " "${UMFPACK_LIBRARIES}")
-  MESSAGE(STATUS " UMFPACK headers: " "${UMFPACK_INCLUDE_DIR}")
-  MARK_AS_ADVANCED(HAVE_UMFPACK)
-  MESSAGE(STATUS "------------------------------------------------")
-ELSE()
-  MESSAGE(STATUS " UMFPACK library: Using internal Elmer library")
+IF(WITH_UMFPACK)
+  IF(UMFPACK_FOUND)
+    MESSAGE(STATUS " UMFPACK library: " "${UMFPACK_LIBRARIES}")
+    MESSAGE(STATUS " UMFPACK headers: " "${UMFPACK_INCLUDE_DIR}")
+    MESSAGE(STATUS "------------------------------------------------")
+  ELSE()
+    MESSAGE(STATUS " UMFPACK library: Using internal Elmer library")
+  ENDIF()
 ENDIF()
 IF(CHOLMOD_FOUND AND SPQR_FOUND)
   MESSAGE(STATUS " CHOLMOD library: " "${CHOLMOD_LIBRARIES}")
diff --git a/fem/config.h.cmake b/fem/config.h.cmake
index 67dc31e1f2..ccb47dd9a4 100644
--- a/fem/config.h.cmake
+++ b/fem/config.h.cmake
@@ -139,7 +139,7 @@
 #define HAVE_SYS_TYPES_H
 
 /* Define if you have a UMFPACK library. */
-#define HAVE_UMFPACK
+#cmakedefine HAVE_UMFPACK
 
 /* Define to the Fortran type that matches SuiteSparse_long. */
 #cmakedefine UMFPACK_LONG_FORTRAN_TYPE @UMFPACK_LONG_FORTRAN_TYPE@