The Perl Toolchain Summit needs more sponsors. If your company depends on Perl, please support this very important event.
#define IMPORT_VTABLE(ptr,type,name) do {                       \
  ptr = INT2PTR(type *,SvIV(get_sv(name,GV_ADDWARN|GV_ADD)));   \
  if ((*ptr->tabSize)() != sizeof(type)) {                      \
    Perl_warn(aTHX_ "%s wrong size for %s",name,#type);         \
  }                                                             \
 } while (0)

#ifdef WIN32
#define DECLARE_VTABLES	\
LangVtab           *LangVptr;          \
TcldeclsVtab       *TcldeclsVptr;      \
TkVtab             *TkVptr;            \
TkdeclsVtab        *TkdeclsVptr;       \
TkeventVtab        *TkeventVptr;       \
TkglueVtab         *TkglueVptr;        \
TkintVtab          *TkintVptr;         \
TkintdeclsVtab     *TkintdeclsVptr;    \
TkintplatdeclsVtab *TkintplatdeclsVptr;\
TkintxlibdeclsVtab *TkintxlibdeclsVptr;\
TkoptionVtab       *TkoptionVptr;      \
TkplatdeclsVtab    *TkplatdeclsVptr

#define IMPORT_VTABLES	do { \
IMPORT_VTABLE(LangVptr          ,          LangVtab,"Tk::LangVtab");           \
IMPORT_VTABLE(TcldeclsVptr      ,      TcldeclsVtab,"Tk::TcldeclsVtab");       \
IMPORT_VTABLE(TkVptr            ,            TkVtab,"Tk::TkVtab");             \
IMPORT_VTABLE(TkdeclsVptr       ,       TkdeclsVtab,"Tk::TkdeclsVtab");        \
IMPORT_VTABLE(TkeventVptr       ,       TkeventVtab,"Tk::TkeventVtab");        \
IMPORT_VTABLE(TkglueVptr        ,        TkglueVtab,"Tk::TkglueVtab");         \
IMPORT_VTABLE(TkintVptr         ,         TkintVtab,"Tk::TkintVtab");          \
IMPORT_VTABLE(TkintdeclsVptr    ,    TkintdeclsVtab,"Tk::TkintdeclsVtab");     \
IMPORT_VTABLE(TkintplatdeclsVptr,TkintplatdeclsVtab,"Tk::TkintplatdeclsVtab"); \
IMPORT_VTABLE(TkintxlibdeclsVptr,TkintxlibdeclsVtab,"Tk::TkintxlibdeclsVtab"); \
IMPORT_VTABLE(TkoptionVptr      ,      TkoptionVtab,"Tk::TkoptionVtab");       \
IMPORT_VTABLE(TkplatdeclsVptr   ,   TkplatdeclsVtab,"Tk::TkplatdeclsVtab");    \
} while (0)
#else
#define DECLARE_VTABLES	\
LangVtab           *LangVptr;          \
TcldeclsVtab       *TcldeclsVptr;      \
TkVtab             *TkVptr;            \
TkdeclsVtab        *TkdeclsVptr;       \
TkeventVtab        *TkeventVptr;       \
TkglueVtab         *TkglueVptr;        \
TkintVtab          *TkintVptr;         \
TkintdeclsVtab     *TkintdeclsVptr;    \
TkoptionVtab       *TkoptionVptr;      \
XlibVtab           *XlibVptr

#define IMPORT_VTABLES	do { \
IMPORT_VTABLE(LangVptr          ,          LangVtab,"Tk::LangVtab");           \
IMPORT_VTABLE(TcldeclsVptr      ,      TcldeclsVtab,"Tk::TcldeclsVtab");       \
IMPORT_VTABLE(TkVptr            ,            TkVtab,"Tk::TkVtab");             \
IMPORT_VTABLE(TkdeclsVptr       ,       TkdeclsVtab,"Tk::TkdeclsVtab");        \
IMPORT_VTABLE(TkeventVptr       ,       TkeventVtab,"Tk::TkeventVtab");        \
IMPORT_VTABLE(TkglueVptr        ,        TkglueVtab,"Tk::TkglueVtab");         \
IMPORT_VTABLE(TkintVptr         ,         TkintVtab,"Tk::TkintVtab");          \
IMPORT_VTABLE(TkintdeclsVptr    ,    TkintdeclsVtab,"Tk::TkintdeclsVtab");     \
IMPORT_VTABLE(TkoptionVptr      ,      TkoptionVtab,"Tk::TkoptionVtab");       \
IMPORT_VTABLE(XlibVptr          ,          XlibVtab,"Tk::XlibVtab");           \
} while (0)
#endif
#define DECLARE_TIX	\
TixVtab            *TixVptr;           \
TixintVtab         *TixintVptr

#define IMPORT_TIX	do { \
IMPORT_VTABLE(TixVptr           ,           TixVtab,"Tk::TixVtab");            \
IMPORT_VTABLE(TixintVptr        ,        TixintVtab,"Tk::TixintVtab");         \
} while (0)
#define DECLARE_PHOTO	\
ImgintVtab         *ImgintVptr;        \
TkimgphotoVtab     *TkimgphotoVptr

#define IMPORT_PHOTO	do { \
IMPORT_VTABLE(ImgintVptr        ,        ImgintVtab,"Tk::ImgintVtab");         \
IMPORT_VTABLE(TkimgphotoVptr    ,    TkimgphotoVtab,"Tk::TkimgphotoVtab");     \
} while (0)
#define DECLARE_EVENT	\
TkeventVtab        *TkeventVptr

#define IMPORT_EVENT	do { \
IMPORT_VTABLE(TkeventVptr       ,       TkeventVtab,"Tk::TkeventVtab");        \
} while (0)
#define DECLARE_TIXXPM	\
TiximgxpmVtab      *TiximgxpmVptr

#define IMPORT_TIXXPM	do { \
IMPORT_VTABLE(TiximgxpmVptr     ,     TiximgxpmVtab,"Tk::TiximgxpmVtab");      \
} while (0)