Temporary header file '/tmp/EuQcbPaW15/dump1.h' with the following content will be compiled to create GCC translation unit dump: // add defines #define __STDC_VERSION__ 201710L #define _GXX_NULLPTR_T #define CLUTTER_ENABLE_COMPOSITOR_API 1 #define _REGEX_NELTS(n) #define _Atomic #define PACKED // add includes #include "/usr/include/lmdb.h" // add classes MDB_envinfo* tmp_add_class_0; MDB_stat* tmp_add_class_1; MDB_val* tmp_add_class_2; The GCC parameters: gcc -fdump-lang-raw -fkeep-inline-functions -c -x c++ -fpermissive -w "/tmp/EuQcbPaW15/dump1.h"