CMake: setting compiler higher to avoid conflicts, and linking libopenmp

src/CMakeLists.txt

-cmake_minimum_required(VERSION 3.10)
+cmake_minimum_required(VERSION 3.9)
+
+SET(CMAKE_C_COMPILER gcc)
+
 set(CMAKE_POSITION_INDEPENDENT_CODE ON)
 
 SET(PYTHONLIB "po" CACHE STRING "Location of the python site-package directory")
 
-project (cobitools3)
-set(CMAKE_BUILD_TYPE Release)
+project (cobitools3 LANGUAGES C)
 
-SET(CMAKE_C_COMPILER gcc)
+set(CMAKE_BUILD_TYPE Release)
 
 include_directories(${CMAKE_CURRENT_SOURCE_DIR})
+
 file(GLOB_RECURSE CSRC "*.c")
 
 add_library(cobitools3 SHARED   obierrno.c
@@ -61,6 +64,11 @@ add_library(cobitools3 SHARED   obierrno.c
 								libecoPCR/ecoError.c
 								obitypes.c
 								array_indexer.c)
-								
+
+find_package(OpenMP)
+if(OpenMP_C_FOUND)
+    target_link_libraries(cobitools3 PUBLIC OpenMP::OpenMP_C)
+endif()
+					
 install(TARGETS cobitools3 DESTINATION ${PYTHONLIB})
 								
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