From 162d1a14df43f89d76066997b42428df0a6138ce Mon Sep 17 00:00:00 2001
From: Sam Reeve <6740307+streeve@users.noreply.github.com>
Date: Tue, 15 Oct 2024 14:59:52 -0400
Subject: [PATCH] Check for heffte host backends at configure

---
 CMakeLists.txt | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index c79cb5931..963bef08d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -99,6 +99,12 @@ set_package_properties(HYPRE PROPERTIES TYPE OPTIONAL PURPOSE "Used for structur
 # find heffte
 Cabana_add_dependency( PACKAGE Heffte VERSION 2.3.0 )
 set_package_properties(Heffte PROPERTIES TYPE OPTIONAL PURPOSE "Used for fft calculations")
+if(HEFFTE_FOUND)
+  # ensure at least one host backend is enabled
+  if(NOT Heffte_ENABLE_FFTW AND NOT Heffte_ENABLE_MKL)
+    message(FATAL_ERROR "Cabana heFFTe support requires at least one host backend (FFTW or MKL).")
+  endif()
+endif()
 
 # find Silo
 Cabana_add_dependency( PACKAGE SILO )