Detect if _FILE_OFFSET_BITS=64 is required at configuration time via …

…try_compile

cmake/CheckCompilerFunctionality.cmake

@@ -138,6 +138,25 @@ function(flamegpu_check_compiler_functionality)
         endif()
     endif()
 
+    if (NOT MSVC)
+        # Jitify2 on linux requires uses F_OFD_SETLKW or -D_FILE_OFFSET_BITS=64. 
+        # Cannot detect the presence of this from CMAKE_SYSTEM_VERSION when in a container, so try to compile with it and if an error occurs then we must define this option.
+        # If required, sets a cmake cahce internal variable FLAMEGPU__FILE_OFFSET_BITS_64_REQUIRED to true
+        try_compile(
+            LINUX_F_OFD_SETLKW
+            "${CMAKE_CURRENT_BINARY_DIR}/try_compile"
+            "${CMAKE_CURRENT_LIST_DIR}/CheckCompilerFunctionality/F_OFD_SETLKW.cpp"
+            CXX_STANDARD 17
+            CUDA_STANDARD 17
+            CXX_STANDARD_REQUIRED "ON"
+        )
+        if(NOT LINUX_F_OFD_SETLKW)
+            set(FLAMEGPU__FILE_OFFSET_BITS_64_REQUIRED "true" CACHE INTERNAL "if _FILE_OFFSET_BITS=64 required for jitify2")
+        else()
+            set(FLAMEGPU__FILE_OFFSET_BITS_64_REQUIRED "false" CACHE INTERNAL "if _FILE_OFFSET_BITS=64 required for jitify2")
+        endif()
+    endif()
+
     # If we made it this far, set the result variable to be truthy
     set(FLAMEGPU_CheckCompilerFunctionality_RESULT "YES" PARENT_SCOPE)
 endfunction()

cmake/CheckCompilerFunctionality/F_OFD_SETLKW.cpp

@@ -0,0 +1,10 @@
+#ifdef __linux__
+#include <fcntl.h>
+#endif  // __linux__
+
+int main (int argc, char * argv[]) {
+    #ifndef F_OFD_SETLKW
+    #error F_OFD_SETLKW is not defined; try building with -D_FILE_OFFSET_BITS=64
+    #endif  // F_OFD_SETLKW
+    return 0;
+}

src/CMakeLists.txt

@@ -612,10 +612,11 @@ if(FLAMEGPU_ENABLE_NVTX AND TARGET NVTX::nvtx)
     unset(nvtxversion)
 endif()
 
-# Jitify2 requires separate compilation options for older linux kernels (i.e. manylinux2014), so detect and set an additional compile definition in this case
-# if(CMAKE_SYSTEM_VERSION VERSION_LESS 3.15)
+# Jitify2 requires separate compilation options for older linux kernels (i.e. manylinux2014).
+# This is detected in cmake/CheckCompilerFunctionality.cmake and a boolean internal cache variable is stores if this is required or not.
+if(FLAMEGPU__FILE_OFFSET_BITS_64_REQUIRED)
     target_compile_definitions(${PROJECT_NAME} PUBLIC "_FILE_OFFSET_BITS=64")
-# endif()
+endif()
 target_link_libraries(${PROJECT_NAME} PUBLIC Jitify::jitify)
 # jitify is included in public headers, so this definiition must be public too.
 target_compile_definitions(${PROJECT_NAME} PUBLIC "JITIFY_PRINT_LOG")