From fc68616153190212a7bb7226cdffaa0e6dd4fdb0 Mon Sep 17 00:00:00 2001
From: Michael Uleysky <uleysky@poi.dvo.ru>
Date: Tue, 7 Mar 2023 11:38:00 +1000
Subject: [PATCH] OpenMP required (but still not used) for compilation.

---
 CMakeLists.txt | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6a80759..c3753d0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -35,6 +35,13 @@ if(COMPILER_SUPPORTS_CXX20)
 else()
   message(FATAL_ERROR "The compiler ${CMAKE_CXX_COMPILER} has no C++20 support. Please use a different C++ compiler.")
 endif()
+# OpenMP is required
+CHECK_CXX_COMPILER_FLAG(-fopenmp COMPILER_SUPPORTS_OPENMP)
+if(COMPILER_SUPPORTS_OPENMP)
+ set(default_options ${default_options} -fopenmp)
+else()
+  message(FATAL_ERROR "The compiler ${CMAKE_CXX_COMPILER} has no OpenMP support. Please use a different C++ compiler.")
+endif()
 # Link time optimization check
 set(CMAKE_REQUIRED_FLAGS -flto)
 CHECK_CXX_COMPILER_FLAG(-flto COMPILER_SUPPORTS_FLTO)