Temporary header file '/tmp/qAagtQxU2i/dump1.h' with the following content will be compiled to create GCC translation unit dump:

  // add defines
  #define __STDC_VERSION__ 201710L
#define _FILE_OFFSET_BITS 64
#define _GXX_NULLPTR_T
#define CLUTTER_ENABLE_COMPOSITOR_API 1
#define _REGEX_NELTS(n)
#define _Atomic
#define PACKED
#ifdef __cplusplus
// C17 compat layer
#define _Alignof(type) alignof(type)
#endif
#define getaddrinfo_a(a,b,c,d) 
#define FLOAT_MATH_FUNCTIONS

  // add includes
  #include "/usr/include/fox-1.6/fx.h"
  #include "/usr/include/fox-1.6/fx3d.h"
  #include "/usr/include/fox-1.6/fxascii.h"
  #include "/usr/include/fox-1.6/fxdefs.h"
  #include "/usr/include/fox-1.6/fxkeys.h"
  #include "/usr/include/fox-1.6/fxunicode.h"
  #include "/usr/include/fox-1.6/fxver.h"

  // add namespaces
  namespace FX{typedef int tmp_add_type_1;}
  FX::tmp_add_type_1 tmp_add_func_1(){return 0;};
  namespace FX{namespace Ascii{typedef int tmp_add_type_2;}}
  FX::Ascii::tmp_add_type_2 tmp_add_func_2(){return 0;};
  namespace FX{namespace FXPath{typedef int tmp_add_type_3;}}
  FX::FXPath::tmp_add_type_3 tmp_add_func_3(){return 0;};
  namespace FX{namespace FXSystem{typedef int tmp_add_type_4;}}
  FX::FXSystem::tmp_add_type_4 tmp_add_func_4(){return 0;};
  namespace FX{namespace FXURL{typedef int tmp_add_type_5;}}
  FX::FXURL::tmp_add_type_5 tmp_add_func_5(){return 0;};
  namespace FX{namespace Unicode{typedef int tmp_add_type_6;}}
  FX::Unicode::tmp_add_type_6 tmp_add_func_6(){return 0;};

  // add classes
  _G_fpos64_t* tmp_add_class_0;
  _G_fpos_t* tmp_add_class_1;
  _IO_cookie_io_functions_t* tmp_add_class_2;

The GCC parameters:
  gcc -fdump-lang-raw -fkeep-inline-functions -c -x c++ -fpermissive -w "/tmp/qAagtQxU2i/dump1.h"