Temporary header file '/tmp/23BN_neZaH/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)

  // add includes
  #include "/usr/include/c++/12/cstddef"
  #include "/usr/include/libotr/tlv.h"
  #include "/usr/include/libotr/proto.h"
  #include "/usr/include/libotr/auth.h"
  #include "/usr/include/libotr/b64.h"
  #include "/usr/include/libotr/context.h"
  #include "/usr/include/libotr/context_priv.h"
  #include "/usr/include/libotr/dh.h"
  #include "/usr/include/libotr/instag.h"
  #include "/usr/include/libotr/mem.h"
  #include "/usr/include/libotr/message.h"
  #include "/usr/include/libotr/privkey-t.h"
  #include "/usr/include/libotr/privkey.h"
  #include "/usr/include/libotr/serial.h"
  #include "/usr/include/libotr/sm.h"
  #include "/usr/include/libotr/userstate.h"
  #include "/usr/include/libotr/version.h"

  // 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;
  _gpgrt__stream* tmp_add_class_3;
  _gpgrt_cookie_io_functions* tmp_add_class_4;
  _gpgrt_poll_s* tmp_add_class_5;
  _gpgrt_syshd* tmp_add_class_6;
  context* tmp_add_class_7;
  context_priv* tmp_add_class_8;
  gcry_kdf_thread_ops* tmp_add_class_9;
  gcry_md_handle* tmp_add_class_10;
  gcry_thread_cbs* tmp_add_class_11;
  s_OtrlInsTag* tmp_add_class_12;
  s_OtrlMessageAppOps* tmp_add_class_13;
  s_OtrlPendingPrivKey* tmp_add_class_14;
  s_OtrlPrivKey* tmp_add_class_15;
  s_OtrlTLV* tmp_add_class_16;
  s_OtrlUserState* tmp_add_class_17;
  s_fingerprint* tmp_add_class_18;

The GCC parameters:
  gcc -fdump-lang-raw -fkeep-inline-functions -c -x c++ -fpermissive -w "/tmp/23BN_neZaH/dump1.h"