text: /*
  ** $Id: ldo.h,v 2.29.1.1 2017/04/19 17:20:42 roberto Exp $
  ** Stack and Call structure of Lua
  ** See Copyright Notice in lua.h
  */
  
  #ifndef ldo_h
  #define ldo_h
  
  
  #include "lobject.h"
  #include "lstate.h"
  #include "lzio.h"
  
  
  /*
  ** Macro to check stack size and grow stack if needed.  Parameters
  ** 'pre'/'pos' allow the macro to preserve a pointer into the
  ** stack across reallocations, doing the work only when needed.
  ** 'condmovestack' is used in heavy tests to force a stack reallocation
  ** at every check.
  */
  #define luaD_checkstackaux(L,n,pre,pos)  \
  	if (L->stack_last - L->top <= (n)) \
  	  { pre; luaD_growstack(L, n); pos; } else { condmovestack(L,pre,pos); }
  
  /* In general, 'pre'/'pos' are empty (nothing to save) */
  #define luaD_checkstack(L,n)	luaD_checkstackaux(L,n,(void)0,(void)0)
  
  
  
  #define savestack(L,p)		((char *)(p) - (char *)L->stack)
  #define restorestack(L,n)	((TValue *)((char *)L->stack + (n)))
  
  
  /* type of protected functions, to be ran by 'runprotected' */
  typedef void (*Pfunc) (lua_State *L, void *ud);
  
  LUAI_FUNC int luaD_protectedparser (lua_State *L, ZIO *z, const char *name,
                                                    const char *mode);
  LUAI_FUNC void luaD_hook (lua_State *L, int event, int line);
  LUAI_FUNC int luaD_precall (lua_State *L, StkId func, int nresults, int need_adjust);
  LUAI_FUNC void luaD_call (lua_State *L, StkId func, int nResults);
  LUAI_FUNC void luaD_callnoyield (lua_State *L, StkId func, int nResults);
  LUAI_FUNC int luaD_pcall (lua_State *L, Pfunc func, void *u,
                                          ptrdiff_t oldtop, ptrdiff_t ef);
  LUAI_FUNC int luaD_poscall (lua_State *L, CallInfo *ci, StkId firstResult,
                                            int nres);
  LUAI_FUNC void luaD_reallocstack (lua_State *L, int newsize);
  LUAI_FUNC void luaD_growstack (lua_State *L, int n);
  LUAI_FUNC void luaD_shrinkstack (lua_State *L);
  LUAI_FUNC void luaD_inctop (lua_State *L);
  
  LUAI_FUNC l_noret luaD_throw (lua_State *L, int errcode);
  LUAI_FUNC int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud);
  
  #endif
  
  