Set minimum CMake version for INDEX64_EXT_API to 3.18 due to the need of the Fortran_PREPROCESS target property

Author: ACSimon33

CMakeLists.txt

@@ -109,7 +109,7 @@ else()
 endif()
 # By default build extended _64 API for supported compilers only
 set(INDEX64_EXT_API_COMPILERS "Intel|GNU")
-option(BUILD_INDEX64_EXT_API "Build Index-64 API as extended API with _64 suffix" ON)
+option(BUILD_INDEX64_EXT_API "Build Index-64 API as extended API with _64 suffix (needs CMake >= 3.18)" ON)
 message(STATUS "Build Index-64 API as extended API with _64 suffix: ${BUILD_INDEX64_EXT_API}")
 
 include(GNUInstallDirs)

SRC/CMakeLists.txt

@@ -541,6 +541,7 @@ if(BUILD_INDEX64_EXT_API)
     set(BUILD_INDEX64_EXT_API OFF)
     set(BUILD_INDEX64_EXT_API OFF PARENT_SCOPE)
   else()
+    cmake_minimum_required(VERSION 3.18)
     set(SOURCES_64)
     file(MAKE_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/${LAPACKLIB}_64_obj)
     file(COPY ${SOURCES} DESTINATION ${CMAKE_CURRENT_BINARY_DIR}/${LAPACKLIB}_64_obj)

TESTING/MATGEN/CMakeLists.txt

@@ -61,6 +61,7 @@ if(BUILD_INDEX64_EXT_API)
     set(BUILD_INDEX64_EXT_API OFF)
     set(BUILD_INDEX64_EXT_API OFF PARENT_SCOPE)
   else()
+    cmake_minimum_required(VERSION 3.18)
     set(SOURCES_64)
     file(MAKE_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/${TMGLIB}_64_obj)
     file(COPY ${SOURCES} DESTINATION ${CMAKE_CURRENT_BINARY_DIR}/${TMGLIB}_64_obj)