text: /*
  ** $Id: ldo.h,v 2.7.1.1 2007/12/27 13:02:25 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"
  
  
  #define luaD_checkstack(L,n)	\
    if ((char *)L->stack_last - (char *)L->top <= (n)*(int)sizeof(TValue)) \
      luaD_growstack(L, n); \
    else condhardstacktests(luaD_reallocstack(L, L->stacksize - EXTRA_STACK - 1));
  
  
  #define incr_top(L) {luaD_checkstack(L,1); L->top++;}
  
  #define savestack(L,p)		((char *)(p) - (char *)L->stack)
  #define restorestack(L,n)	((TValue *)((char *)L->stack + (n)))
  
  #define saveci(L,p)		((char *)(p) - (char *)L->base_ci)
  #define restoreci(L,n)		((CallInfo *)((char *)L->base_ci + (n)))
  
  
  /* results from luaD_precall */
  #define PCRLUA		0	/* initiated a call to a Lua function */
  #define PCRC		1	/* did a call to a C function */
  #define PCRYIELD	2	/* C funtion yielded */
  
  
  /* 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);
  LUAI_FUNC void luaD_callhook (lua_State *L, int event, int line);
  LUAI_FUNC int luaD_precall (lua_State *L, StkId func, int nresults);
  LUAI_FUNC void luaD_call (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, StkId firstResult);
  LUAI_FUNC void luaD_reallocCI (lua_State *L, int newsize);
  LUAI_FUNC void luaD_reallocstack (lua_State *L, int newsize);
  LUAI_FUNC void luaD_growstack (lua_State *L, int n);
  
  LUAI_FUNC void luaD_throw (lua_State *L, int errcode) NORETURN_DECL;
  LUAI_FUNC int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud);
  
  LUAI_FUNC void luaD_seterrorobj (lua_State *L, int errcode, StkId oldtop);
  
  #endif
  
  