Stack and Call structure of Lua

1 files changed, 0 insertions, 1484 deletions

diff --git a/opcode.c b/opcode.c
deleted file mode 100644
index e569d284..00000000
--- a/opcode.c
+++ /dev/null
@@ -1,1484 +0,0 @@
-/*
-** opcode.c
-** TecCGraf - PUC-Rio
-*/
-
-char *rcs_opcode="$Id: opcode.c,v 4.21 1997/07/31 19:37:37 roberto Exp roberto $";
-
-#include <setjmp.h>
-#include <stdio.h>
-#include <string.h>
-#include <stdlib.h>
-
-#include "lualoc.h"
-#include "luadebug.h"
-#include "luamem.h"
-#include "opcode.h"
-#include "hash.h"
-#include "inout.h"
-#include "table.h"
-#include "lua.h"
-#include "fallback.h"
-#include "auxlib.h"
-#include "lex.h"
-
-#define tonumber(o) ((ttype(o) != LUA_T_NUMBER) && (lua_tonumber(o) != 0))
-#define tostring(o) ((ttype(o) != LUA_T_STRING) && (lua_tostring(o) != 0))
-
-
-#define get_word(w,pc)  {w=*pc+(*(pc+1)<<8); pc+=2;}
-
-
-#define STACK_SIZE      128
-
-#ifndef STACK_LIMIT
-#define STACK_LIMIT     6000
-#endif
-
-typedef int StkId;  /* index to stack elements */
-
-static TObject initial_stack;
-
-static TObject *stackLimit = &initial_stack+1;
-static TObject *stack = &initial_stack;
-static TObject *top = &initial_stack;
-
-
-/* macros to convert from lua_Object to (TObject *) and back */
- 
-#define Address(lo)     ((lo)+stack-1)
-#define Ref(st)         ((st)-stack+1)
- 
-
-/* macro to increment stack top. There must be always an empty slot in
-*  the stack
-*/
-#define incr_top        if (++top >= stackLimit) growstack()
-
-struct C_Lua_Stack {
-  StkId base;  /* when Lua calls C or C calls Lua, points to */
-               /* the first slot after the last parameter. */
-  StkId lua2C; /* points to first element of "array" lua2C */
-  int num;     /* size of "array" lua2C */
-};
-
-static struct C_Lua_Stack CLS_current = {0, 0, 0};
-
-static  jmp_buf *errorJmp = NULL; /* current error recover point */
-
-
-/* Hooks */
-lua_LHFunction lua_linehook = NULL;
-lua_CHFunction lua_callhook = NULL;
-
-
-static StkId lua_execute (TFunc *func, StkId base);
-static void do_call (StkId base, int nResults);
-
-
-
-TObject *luaI_Address (lua_Object o)
-{
-  return Address(o);
-}
-
-
-/*
-** Init stack
-*/
-static void lua_initstack (void)
-{
- Long maxstack = STACK_SIZE;
- stack = newvector(maxstack, TObject);
- stackLimit = stack+maxstack;
- top = stack;
- *(top++) = initial_stack;
-}
-
-
-/*
-** Check stack overflow and, if necessary, realloc vector
-*/
-#define lua_checkstack(nt)  if ((nt) >= stackLimit) growstack()
-
-static void growstack (void)
-{
- if (stack == &initial_stack)
-   lua_initstack();
- else
- {
-  static int limit = STACK_LIMIT;
-  StkId t = top-stack;
-  Long stacksize = stackLimit - stack;
-  stacksize = growvector(&stack, stacksize, TObject, stackEM, limit+100);
-  stackLimit = stack+stacksize;
-  top = stack + t;
-  if (stacksize >= limit)
-  {
-    limit = stacksize;
-    lua_error(stackEM);
-  }
- }
-}
-
-
-/*
-** Concatenate two given strings. Return the new string pointer.
-*/
-static char *lua_strconc (char *l, char *r)
-{
-  size_t nl = strlen(l);
-  char *buffer = luaI_buffer(nl+strlen(r)+1);
-  strcpy(buffer, l);
-  strcpy(buffer+nl, r);
-  return buffer;
-}
-
-
-/*
-** Convert, if possible, to a number object.
-** Return 0 if success, not 0 if error.
-*/
-static int lua_tonumber (TObject *obj)
-{
-  double t;
-  char c;
-  if (ttype(obj) != LUA_T_STRING)
-    return 1;
-  else if (sscanf(svalue(obj), "%lf %c",&t, &c) == 1) {
-    nvalue(obj) = (real)t;
-    ttype(obj) = LUA_T_NUMBER;
-    return 0;
-  }
-  else
-    return 2;
-}
-
-
-/*
-** Convert, if possible, to a string ttype
-** Return 0 in success or not 0 on error.
-*/
-static int lua_tostring (TObject *obj)
-{
-  if (ttype(obj) != LUA_T_NUMBER)
-    return 1;
-  else {
-    char s[60];
-    real f = nvalue(obj);
-    int i;
-    if ((real)(-MAX_INT) <= f && f <= (real)MAX_INT && (real)(i=(int)f) == f)
-      sprintf (s, "%d", i);
-    else
-      sprintf (s, "%g", (double)nvalue(obj));
-    tsvalue(obj) = luaI_createstring(s);
-    ttype(obj) = LUA_T_STRING;
-    return 0;
-  }
-}
-
-
-/*
-** Adjust stack. Set top to the given value, pushing NILs if needed.
-*/
-static void adjust_top_aux (StkId newtop)
-{
-  TObject *nt;
-  lua_checkstack(stack+newtop);
-  nt = stack+newtop;  /* warning: previous call may change stack */
-  while (top < nt) ttype(top++) = LUA_T_NIL;
-}
-
-
-#define adjust_top(newtop)  { if (newtop <= top-stack) \
-                                 top = stack+newtop; \
-                              else adjust_top_aux(newtop); }
-
-#define adjustC(nParams)        adjust_top(CLS_current.base+nParams)
-
-
-static void checkCparams (int nParams)
-{
-  if (top-stack < CLS_current.base+nParams)
-    lua_error("API error - wrong number of arguments in C2lua stack");
-}
-
-
-/*
-** Open a hole below "nelems" from the top.
-*/
-static void open_stack (int nelems)
-{
-  int i;
-  for (i=0; i<nelems; i++)
-    *(top-i) = *(top-i-1);
-  incr_top;
-}
-
-
-static lua_Object put_luaObject (TObject *o)
-{
-  open_stack((top-stack)-CLS_current.base);
-  stack[CLS_current.base++] = *o;
-  return CLS_current.base;  /* this is +1 real position (see Ref) */
-}
-
-
-static lua_Object put_luaObjectonTop (void)
-{
-  open_stack((top-stack)-CLS_current.base);
-  stack[CLS_current.base++] = *(--top);
-  return CLS_current.base;  /* this is +1 real position (see Ref) */
-}
-
-
-lua_Object lua_pop (void)
-{
-  checkCparams(1);
-  return put_luaObjectonTop();
-}
-
-
-
-/*
-** call Line hook
-*/
-static void lineHook (int line)
-{
-  struct C_Lua_Stack oldCLS = CLS_current;
-  StkId old_top = CLS_current.lua2C = CLS_current.base = top-stack;
-  CLS_current.num = 0;
-  (*lua_linehook)(line);
-  top = stack+old_top;
-  CLS_current = oldCLS;
-}
-
-
-/*
-** Call hook
-** The function being called is in [stack+base-1]
-*/
-static void callHook (StkId base, lua_Type type, int isreturn)
-{
-  struct C_Lua_Stack oldCLS = CLS_current;
-  StkId old_top = CLS_current.lua2C = CLS_current.base = top-stack;
-  CLS_current.num = 0;
-  if (isreturn)
-    (*lua_callhook)(LUA_NOOBJECT, "(return)", 0);
-  else
-  {
-    TObject *f = stack+base-1;
-    if (type == LUA_T_MARK)
-      (*lua_callhook)(Ref(f), f->value.tf->fileName->str,
-                      f->value.tf->lineDefined);
-    else
-      (*lua_callhook)(Ref(f), "(C)", -1);
-  }
-  top = stack+old_top;
-  CLS_current = oldCLS;
-}
-
-
-/*
-** Call a C function. CLS_current.base will point to the top of the stack,
-** and CLS_current.num is the number of parameters. Returns an index
-** to the first result from C.
-*/
-static StkId callC (lua_CFunction func, StkId base)
-{
-  struct C_Lua_Stack oldCLS = CLS_current;
-  StkId firstResult;
-  CLS_current.num = (top-stack) - base;
-  /* incorporate parameters on the stack */
-  CLS_current.lua2C = base;
-  CLS_current.base = base+CLS_current.num;  /* == top-stack */
-  if (lua_callhook)
-    callHook(base, LUA_T_CMARK, 0);
-  (*func)();
-  if (lua_callhook)  /* func may have changed lua_callhook */
-    callHook(base, LUA_T_CMARK, 1);
-  firstResult = CLS_current.base;
-  CLS_current = oldCLS;
-  return firstResult;
-}
-
-static void callIM (TObject *f, int nParams, int nResults)
-{
-  open_stack(nParams);
-  *(top-nParams-1) = *f;
-  do_call((top-stack)-nParams, nResults);
-}
-
-
-/*
-** Call a function (C or Lua). The parameters must be on the stack,
-** between [stack+base,top). The function to be called is at stack+base-1.
-** When returns, the results are on the stack, between [stack+base-1,top).
-** The number of results is nResults, unless nResults=MULT_RET.
-*/
-static void do_call (StkId base, int nResults)
-{
-  StkId firstResult;
-  TObject *func = stack+base-1;
-  int i;
-  if (ttype(func) == LUA_T_CFUNCTION) {
-    ttype(func) = LUA_T_CMARK;
-    firstResult = callC(fvalue(func), base);
-  }
-  else if (ttype(func) == LUA_T_FUNCTION) {
-    ttype(func) = LUA_T_MARK;
-    firstResult = lua_execute(func->value.tf, base);
-  }
-  else { /* func is not a function */
-    /* Check the tag method for invalid functions */
-    TObject *im = luaI_getimbyObj(func, IM_FUNCTION);
-    if (ttype(im) == LUA_T_NIL)
-      lua_error("call expression not a function");
-    open_stack((top-stack)-(base-1));
-    stack[base-1] = *im;
-    do_call(base, nResults);
-    return;
-  }
-  /* adjust the number of results */
-  if (nResults != MULT_RET)
-    adjust_top(firstResult+nResults);
-  /* move results to base-1 (to erase parameters and function) */
-  base--;
-  nResults = top - (stack+firstResult);  /* actual number of results */
-  for (i=0; i<nResults; i++)
-    *(stack+base+i) = *(stack+firstResult+i);
-  top -= firstResult-base;
-}
-
-
-/*
-** Function to index a table. Receives the table at top-2 and the index
-** at top-1.
-*/
-static void pushsubscript (void)
-{
-  TObject *im;
-  if (ttype(top-2) != LUA_T_ARRAY)  /* not a table, get "gettable" method */
-    im = luaI_getimbyObj(top-2, IM_GETTABLE);
-  else {  /* object is a table... */
-    int tg = (top-2)->value.a->htag;
-    im = luaI_getim(tg, IM_GETTABLE);
-    if (ttype(im) == LUA_T_NIL) {  /* and does not have a "gettable" method */
-      TObject *h = lua_hashget(avalue(top-2), top-1);
-      if (h != NULL && ttype(h) != LUA_T_NIL) {
-        --top;
-        *(top-1) = *h;
-      }
-      else if (ttype(im=luaI_getim(tg, IM_INDEX)) != LUA_T_NIL)
-        callIM(im, 2, 1);
-      else {
-        --top;
-        ttype(top-1) = LUA_T_NIL;
-      }
-      return;
-    }
-    /* else it has a "gettable" method, go through to next command */
-  }
-  /* object is not a table, or it has a "gettable" method */ 
-  if (ttype(im) != LUA_T_NIL)
-    callIM(im, 2, 1);
-  else
-    lua_error("indexed expression not a table");
-}
-
-
-lua_Object lua_rawgettable (void)
-{
-  checkCparams(2);
-  if (ttype(top-2) != LUA_T_ARRAY)
-    lua_error("indexed expression not a table in raw gettable");
-  else {
-    TObject *h = lua_hashget(avalue(top-2), top-1);
-    --top;
-    if (h != NULL)
-      *(top-1) = *h;
-    else
-      ttype(top-1) = LUA_T_NIL;
-  }
-  return put_luaObjectonTop();
-}
-
-
-/*
-** Function to store indexed based on values at the top
-** mode = 0: raw store (without internal methods)
-** mode = 1: normal store (with internal methods)
-** mode = 2: "deep stack" store (with internal methods)
-*/
-static void storesubscript (TObject *t, int mode)
-{
-  TObject *im = (mode == 0) ? NULL : luaI_getimbyObj(t, IM_SETTABLE);
-  if (ttype(t) == LUA_T_ARRAY && (im == NULL || ttype(im) == LUA_T_NIL)) {
-    TObject *h = lua_hashdefine(avalue(t), t+1);
-    *h = *(top-1);
-    top -= (mode == 2) ? 1 : 3;
-  }
-  else {  /* object is not a table, and/or has a specific "settable" method */
-    if (im && ttype(im) != LUA_T_NIL) {
-      if (mode == 2) {
-        lua_checkstack(top+2);
-        *(top+1) = *(top-1);
-        *(top) = *(t+1);
-        *(top-1) = *t;
-        top += 2;
-      }
-      callIM(im, 3, 0);
-    }
-    else
-      lua_error("indexed expression not a table");
-  }
-}
-
-
-static void getglobal (Word n)
-{
-  TObject *value = &lua_table[n].object;
-  TObject *im = luaI_getimbyObj(value, IM_GETGLOBAL);
-  if (ttype(im) == LUA_T_NIL) {  /* default behavior */
-    *top = *value;
-    incr_top;
-  }
-  else {
-    ttype(top) = LUA_T_STRING;
-    tsvalue(top) = lua_table[n].varname;
-    incr_top;
-    *top = *value;
-    incr_top;
-    callIM(im, 2, 1);
-    }
-}
-
-/*
-** Traverse all objects on stack
-*/
-void lua_travstack (int (*fn)(TObject *))
-{
-  StkId i;
-  for (i = (top-1)-stack; i>=0; i--)
-    fn (stack+i);
-}
-
-
-/*
-** Error messages and debug functions
-*/
-
-
-static void auxerrorim (char *form)
-{
-  lua_Object s = lua_getparam(1);
-  if (lua_isstring(s))
-    fprintf(stderr, form, lua_getstring(s));
-}
-
-
-static void emergencyerrorf (void)
-{
-  auxerrorim("WARNING - THERE WAS AN ERROR INSIDE AN ERROR METHOD:\n%s\n");
-}
-
-
-static void stderrorim (void)
-{
-  auxerrorim("lua: %s\n");
-}
-
-
-TObject luaI_errorim = {LUA_T_CFUNCTION, {stderrorim}};
-
-
-static void lua_message (char *s)
-{
-  TObject im = luaI_errorim;
-  if (ttype(&im) != LUA_T_NIL) {
-    luaI_errorim.ttype = LUA_T_CFUNCTION;
-    luaI_errorim.value.f = emergencyerrorf;
-    lua_pushstring(s);
-    callIM(&im, 1, 0);
-    luaI_errorim = im;
-  }
-}
-
-/*
-** Reports an error, and jumps up to the available recover label
-*/
-void lua_error (char *s)
-{
-  if (s) lua_message(s);
-  if (errorJmp)
-    longjmp(*errorJmp, 1);
-  else
-  {
-    fprintf (stderr, "lua: exit(1). Unable to recover\n");
-    exit(1);
-  }
-}
-
-
-lua_Function lua_stackedfunction (int level)
-{
-  StkId i;
-  for (i = (top-1)-stack; i>=0; i--)
-    if (stack[i].ttype == LUA_T_MARK || stack[i].ttype == LUA_T_CMARK)
-      if (level-- == 0)
-        return Ref(stack+i);
-  return LUA_NOOBJECT;
-}
-
-
-int lua_currentline (lua_Function func)
-{
-  TObject *f = Address(func);
-  return (f+1 < top && (f+1)->ttype == LUA_T_LINE) ? (f+1)->value.i : -1;
-}
-
-
-lua_Object lua_getlocal (lua_Function func, int local_number, char **name)
-{
-  TObject *f = luaI_Address(func);
-  /* check whether func is a Lua function */
-  if (ttype(f) != LUA_T_MARK && ttype(f) != LUA_T_FUNCTION)
-    return LUA_NOOBJECT;
-  *name = luaI_getlocalname(f->value.tf, local_number, lua_currentline(func));
-  if (*name)
-  {
-    /* if "*name", there must be a LUA_T_LINE */
-    /* therefore, f+2 points to function base */
-    return Ref((f+2)+(local_number-1));
-  }
-  else
-    return LUA_NOOBJECT;
-}
-
-int lua_setlocal (lua_Function func, int local_number)
-{
-  TObject *f = Address(func);
-  char *name = luaI_getlocalname(f->value.tf, local_number, lua_currentline(func));
-  checkCparams(1);
-  --top;
-  if (name)
-  {
-    /* if "name", there must be a LUA_T_LINE */
-    /* therefore, f+2 points to function base */
-    *((f+2)+(local_number-1)) = *top;
-    return 1;
-  }
-  else
-    return 0;
-}
-
-/*
-** Call the function at CLS_current.base, and incorporate results on
-** the Lua2C structure.
-*/
-static void do_callinc (int nResults)
-{
-  StkId base = CLS_current.base;
-  do_call(base+1, nResults);
-  CLS_current.lua2C = base;  /* position of the new results */
-  CLS_current.num = (top-stack) - base;  /* number of results */
-  CLS_current.base = base + CLS_current.num;  /* incorporate results on stack */
-}
-
-
-static void do_unprotectedrun (lua_CFunction f, int nParams, int nResults)
-{
-  StkId base = (top-stack)-nParams;
-  open_stack(nParams);
-  stack[base].ttype = LUA_T_CFUNCTION;
-  stack[base].value.f = f;
-  do_call(base+1, nResults);
-}
-
-
-/*
-** Execute a protected call. Assumes that function is at CLS_current.base and
-** parameters are on top of it. Leave nResults on the stack.
-*/
-static int do_protectedrun (int nResults)
-{
-  jmp_buf myErrorJmp;
-  int status;
-  struct C_Lua_Stack oldCLS = CLS_current;
-  jmp_buf *oldErr = errorJmp;
-  errorJmp = &myErrorJmp;
-  if (setjmp(myErrorJmp) == 0) {
-    do_callinc(nResults);
-    status = 0;
-  }
-  else { /* an error occurred: restore CLS_current and top */
-    CLS_current = oldCLS;
-    top = stack+CLS_current.base;
-    status = 1;
-  }
-  errorJmp = oldErr;
-  return status;
-}
-
-int luaI_dorun (TFunc *tf)
-{
-  int status;
-  adjustC(1);  /* one slot for the pseudo-function */
-  stack[CLS_current.base].ttype = LUA_T_FUNCTION;
-  stack[CLS_current.base].value.tf = tf;
-  status = do_protectedrun(MULT_RET);
-  return status;
-}
-
-
-int lua_domain (void)
-{
-  int status;
-  TFunc *tf = new(TFunc);
-  jmp_buf myErrorJmp;
-  jmp_buf *oldErr = errorJmp;
-  errorJmp = &myErrorJmp;
-  luaI_initTFunc(tf);
-  adjustC(1);  /* one slot for the pseudo-function */
-  stack[CLS_current.base].ttype = LUA_T_FUNCTION;
-  stack[CLS_current.base].value.tf = tf;
-  if (setjmp(myErrorJmp) == 0) {
-    lua_parse(tf);
-    status = 0;
-  }
-  else {
-    adjustC(0);  /* erase extra slot */
-    status = 1;
-  }
-  if (status == 0)
-    status = do_protectedrun(MULT_RET);
-  errorJmp = oldErr;
-  return status;
-}
-
-/*
-** Execute the given lua function. Return 0 on success or 1 on error.
-*/
-int lua_callfunction (lua_Object function)
-{
-  if (function == LUA_NOOBJECT)
-    return 1;
-  else
-  {
-    open_stack((top-stack)-CLS_current.base);
-    stack[CLS_current.base] = *Address(function);
-    return do_protectedrun (MULT_RET);
-  }
-}
-
-
-lua_Object lua_gettagmethod (int tag, char *event)
-{
-  lua_pushnumber(tag);
-  lua_pushstring(event);
-  do_unprotectedrun(luaI_gettagmethod, 2, 1);
-  return put_luaObjectonTop();
-}
-
-lua_Object lua_settagmethod (int tag, char *event)
-{
-  TObject newmethod;
-  checkCparams(1);
-  newmethod = *(--top);
-  lua_pushnumber(tag);
-  lua_pushstring(event);
-  *top = newmethod;  incr_top;
-  do_unprotectedrun(luaI_settagmethod, 3, 1);
-  return put_luaObjectonTop();
-}
-
-lua_Object lua_seterrormethod (void)
-{
-  checkCparams(1);
-  do_unprotectedrun(luaI_seterrormethod, 1, 1);
-  return put_luaObjectonTop();
-}
-
-
-/* 
-** API: receives on the stack the table and the index.
-** returns the value.
-*/
-lua_Object lua_gettable (void)
-{
-  checkCparams(2);
-  pushsubscript();
-  return put_luaObjectonTop();
-}
-
-
-#define MAX_C_BLOCKS 10
-
-static int numCblocks = 0;
-static struct C_Lua_Stack Cblocks[MAX_C_BLOCKS];
-
-/*
-** API: starts a new block
-*/
-void lua_beginblock (void)
-{
-  if (numCblocks >= MAX_C_BLOCKS)
-    lua_error("`lua_beginblock': too many nested blocks");
-  Cblocks[numCblocks] = CLS_current;
-  numCblocks++;
-}
-
-/*
-** API: ends a block
-*/
-void lua_endblock (void)
-{
-  --numCblocks;
-  CLS_current = Cblocks[numCblocks];
-  adjustC(0);
-}
-
-void lua_settag (int tag)
-{
-  checkCparams(1);
-  luaI_settag(tag, --top);
-}
-
-/* 
-** API: receives on the stack the table, the index, and the new value.
-*/
-void lua_settable (void)
-{
-  checkCparams(3);
-  storesubscript(top-3, 1);
-}
-
-void lua_rawsettable (void)
-{
-  checkCparams(3);
-  storesubscript(top-3, 0);
-}
-
-/*
-** API: creates a new table
-*/
-lua_Object lua_createtable (void)
-{
-  TObject o;
-  avalue(&o) = lua_createarray(0);
-  ttype(&o) = LUA_T_ARRAY;
-  return put_luaObject(&o);
-}
-
-/*
-** Get a parameter, returning the object handle or LUA_NOOBJECT on error.
-** 'number' must be 1 to get the first parameter.
-*/
-lua_Object lua_lua2C (int number)
-{
-  if (number <= 0 || number > CLS_current.num) return LUA_NOOBJECT;
-  /* Ref(stack+(CLS_current.lua2C+number-1)) ==
-     stack+(CLS_current.lua2C+number-1)-stack+1 == */
-  return CLS_current.lua2C+number;
-}
-
-int lua_isnil (lua_Object o)
-{
-  return (o!= LUA_NOOBJECT) && (ttype(Address(o)) == LUA_T_NIL);
-}
-
-int lua_istable (lua_Object o)
-{
-  return (o!= LUA_NOOBJECT) && (ttype(Address(o)) == LUA_T_ARRAY);
-}
-
-int lua_isuserdata (lua_Object o)
-{
-  return (o!= LUA_NOOBJECT) && (ttype(Address(o)) == LUA_T_USERDATA);
-}
-
-int lua_iscfunction (lua_Object o)
-{
-  int t = lua_tag(o);
-  return (t == LUA_T_CMARK) || (t == LUA_T_CFUNCTION);
-}
-
-int lua_isnumber (lua_Object o)
-{
-  return (o!= LUA_NOOBJECT) && (tonumber(Address(o)) == 0);
-}
-
-int lua_isstring (lua_Object o)
-{
-  int t = lua_tag(o);
-  return (t == LUA_T_STRING) || (t == LUA_T_NUMBER);
-}
-
-int lua_isfunction (lua_Object o)
-{
-  int t = lua_tag(o);
-  return (t == LUA_T_FUNCTION) || (t == LUA_T_CFUNCTION) ||
-         (t == LUA_T_MARK) || (t == LUA_T_CMARK);
-}
-
-/*
-** Given an object handle, return its number value. On error, return 0.0.
-*/
-real lua_getnumber (lua_Object object)
-{
- if (object == LUA_NOOBJECT) return 0.0;
- if (tonumber (Address(object))) return 0.0;
- else return (nvalue(Address(object)));
-}
-
-/*
-** Given an object handle, return its string pointer. On error, return NULL.
-*/
-char *lua_getstring (lua_Object object)
-{
-  if (object == LUA_NOOBJECT || tostring (Address(object)))
-    return NULL;
-  else return (svalue(Address(object)));
-}
-
-
-void *lua_getuserdata (lua_Object object)
-{
-  if (object == LUA_NOOBJECT || ttype(Address(object)) != LUA_T_USERDATA)
-    return NULL;
-  else return tsvalue(Address(object))->u.v;
-}
-
-
-/*
-** Given an object handle, return its cfuntion pointer. On error, return NULL.
-*/
-lua_CFunction lua_getcfunction (lua_Object object)
-{
- if (object == LUA_NOOBJECT || ((ttype(Address(object)) != LUA_T_CFUNCTION) &&
-                                (ttype(Address(object)) != LUA_T_CMARK)))
-   return NULL;
- else return (fvalue(Address(object)));
-}
-
-
-lua_Object lua_getref (int ref)
-{
-  TObject *o = luaI_getref(ref);
-  if (o == NULL)
-    return LUA_NOOBJECT;
-  return put_luaObject(o);
-}
-
-
-int lua_ref (int lock)
-{
-  checkCparams(1);
-  return luaI_ref(--top, lock);
-}
-
-
-
-/*
-** Get a global object.
-*/
-lua_Object lua_getglobal (char *name)
-{
-  getglobal(luaI_findsymbolbyname(name));
-  return put_luaObjectonTop();
-}
-
-
-lua_Object lua_rawgetglobal (char *name)
-{
-  return put_luaObject(&lua_table[luaI_findsymbolbyname(name)].object);
-}
-
-
-/*
-** Store top of the stack at a global variable array field.
-*/
-static void setglobal (Word n)
-{
-  TObject *oldvalue = &lua_table[n].object;
-  TObject *im = luaI_getimbyObj(oldvalue, IM_SETGLOBAL);
-  if (ttype(im) == LUA_T_NIL)  /* default behavior */
-    s_object(n) = *(--top);
-  else {
-    TObject newvalue = *(top-1);
-    ttype(top-1) = LUA_T_STRING;
-    tsvalue(top-1) = lua_table[n].varname;
-    *top = *oldvalue;
-    incr_top;
-    *top = newvalue;
-    incr_top;
-    callIM(im, 3, 0);
-  }
-}
-
-
-void lua_setglobal (char *name)
-{
-  checkCparams(1);
-  setglobal(luaI_findsymbolbyname(name));
-}
-
-void lua_rawsetglobal (char *name)
-{
-  Word n = luaI_findsymbolbyname(name);
-  checkCparams(1);
-  s_object(n) = *(--top);
-}
-
-/*
-** Push a nil object
-*/
-void lua_pushnil (void)
-{
-  ttype(top) = LUA_T_NIL;
-  incr_top;
-}
-
-/*
-** Push an object (ttype=number) to stack.
-*/
-void lua_pushnumber (real n)
-{
- ttype(top) = LUA_T_NUMBER; nvalue(top) = n;
- incr_top;
-}
-
-/*
-** Push an object (ttype=string) to stack.
-*/
-void lua_pushstring (char *s)
-{
-  if (s == NULL)
-    ttype(top) = LUA_T_NIL;
-  else
-  {
-    tsvalue(top) = luaI_createstring(s);
-    ttype(top) = LUA_T_STRING;
-  }
-  incr_top;
-}
-
-
-/*
-** Push an object (ttype=cfunction) to stack.
-*/
-void lua_pushcfunction (lua_CFunction fn)
-{
- ttype(top) = LUA_T_CFUNCTION; fvalue(top) = fn;
- incr_top;
-}
-
-
-
-void lua_pushusertag (void *u, int tag)
-{
-  if (tag < 0 && tag != LUA_ANYTAG)
-    luaI_realtag(tag);  /* error if tag is not valid */
-  tsvalue(top) = luaI_createudata(u, tag);
-  ttype(top) = LUA_T_USERDATA;
-  incr_top;
-}
-
-/*
-** Push an object on the stack.
-*/
-void luaI_pushobject (TObject *o)
-{
- *top = *o;
- incr_top;
-}
-
-/*
-** Push a lua_Object on stack.
-*/
-void lua_pushobject (lua_Object o)
-{
-  if (o == LUA_NOOBJECT)
-    lua_error("API error - attempt to push a NOOBJECT");
-  *top = *Address(o);
-  if (ttype(top) == LUA_T_MARK) ttype(top) = LUA_T_FUNCTION;
-  else if (ttype(top) == LUA_T_CMARK) ttype(top) = LUA_T_CFUNCTION;
-  incr_top;
-}
-
-int lua_tag (lua_Object lo)
-{
-  if (lo == LUA_NOOBJECT) return LUA_T_NIL;
-  else {
-    TObject *o = Address(lo);
-    lua_Type t = ttype(o);
-    if (t == LUA_T_USERDATA)
-      return o->value.ts->tag;
-    else if (t == LUA_T_ARRAY)
-      return o->value.a->htag;
-    else return t;
-  }
-}
-
-
-void luaI_gcIM (TObject *o)
-{
-  TObject *im = luaI_getimbyObj(o, IM_GC);
-  if (ttype(im) != LUA_T_NIL) {
-    *top = *o;
-    incr_top;
-    callIM(im, 1, 0);
-  }
-}
-
-
-static void call_binTM (IMS event, char *msg)
-{
-  TObject *im = luaI_getimbyObj(top-2, event);  /* try first operand */
-  if (ttype(im) == LUA_T_NIL) {
-    im = luaI_getimbyObj(top-1, event);  /* try second operand */
-    if (ttype(im) == LUA_T_NIL) {
-      im = luaI_getim(0, event);  /* try a 'global' i.m. */
-      if (ttype(im) == LUA_T_NIL)
-        lua_error(msg);
-    }
-  }
-  lua_pushstring(luaI_eventname[event]);
-  callIM(im, 3, 1);
-}
-
-
-static void call_arith (IMS event)
-{
-  call_binTM(event, "unexpected type at arithmetic operation");
-}
-
-
-static void comparison (lua_Type ttype_less, lua_Type ttype_equal, 
-                        lua_Type ttype_great, IMS op)
-{
-  TObject *l = top-2;
-  TObject *r = top-1;
-  int result;
-  if (ttype(l) == LUA_T_NUMBER && ttype(r) == LUA_T_NUMBER)
-    result = (nvalue(l) < nvalue(r)) ? -1 : (nvalue(l) == nvalue(r)) ? 0 : 1;
-  else if (ttype(l) == LUA_T_STRING && ttype(r) == LUA_T_STRING)
-    result = strcoll(svalue(l), svalue(r));
-  else {
-    call_binTM(op, "unexpected type at comparison");
-    return;
-  }
-  top--;
-  nvalue(top-1) = 1;
-  ttype(top-1) = (result < 0) ? ttype_less :
-                                (result == 0) ? ttype_equal : ttype_great;
-}
-
-
-static void adjust_varargs (StkId first_extra_arg)
-{
-  TObject arg;
-  TObject *firstelem = stack+first_extra_arg;
-  int nvararg = top-firstelem;
-  int i;
-  if (nvararg < 0) nvararg = 0;
-  avalue(&arg)  = lua_createarray(nvararg+1);  /* +1 for field 'n' */
-  ttype(&arg) = LUA_T_ARRAY;
-  for (i=0; i<nvararg; i++) {
-    TObject index;
-    ttype(&index) = LUA_T_NUMBER;
-    nvalue(&index) = i+1;
-    *(lua_hashdefine(avalue(&arg), &index)) = *(firstelem+i);
-  }
-  /* store counter in field "n" */ {
-    TObject index, extra;
-    ttype(&index) = LUA_T_STRING;
-    tsvalue(&index) = luaI_createstring("n");
-    ttype(&extra) = LUA_T_NUMBER;
-    nvalue(&extra) = nvararg;
-    *(lua_hashdefine(avalue(&arg), &index)) = extra;
-  }
-  adjust_top(first_extra_arg);
-  *top = arg; incr_top;
-}
-
-
-
-/*
-** Execute the given opcode, until a RET. Parameters are between
-** [stack+base,top). Returns n such that the the results are between
-** [stack+n,top).
-*/
-static StkId lua_execute (TFunc *func, StkId base)
-{
-  Byte *pc = func->code;
-  if (lua_callhook)
-    callHook (base, LUA_T_MARK, 0);
- while (1)
- {
-  OpCode opcode;
-  switch (opcode = (OpCode)*pc++)
-  {
-   case PUSHNIL: ttype(top) = LUA_T_NIL; incr_top; break;
-
-   case PUSH0: case PUSH1: case PUSH2:
-     ttype(top) = LUA_T_NUMBER;
-     nvalue(top) = opcode-PUSH0;
-     incr_top;
-     break;
-
-   case PUSHBYTE: 
-     ttype(top) = LUA_T_NUMBER; nvalue(top) = *pc++; incr_top; break;
-
-   case PUSHWORD:
-   {
-    Word w;
-    get_word(w,pc);
-    ttype(top) = LUA_T_NUMBER; nvalue(top) = w;
-    incr_top;
-   }
-   break;
-
-   case PUSHLOCAL0: case PUSHLOCAL1: case PUSHLOCAL2:
-   case PUSHLOCAL3: case PUSHLOCAL4: case PUSHLOCAL5:
-   case PUSHLOCAL6: case PUSHLOCAL7: case PUSHLOCAL8:
-   case PUSHLOCAL9: 
-     *top = *((stack+base) + (int)(opcode-PUSHLOCAL0)); incr_top; break;
-
-   case PUSHLOCAL: *top = *((stack+base) + (*pc++)); incr_top; break;
-
-   case PUSHGLOBAL:
-   {
-    Word w;
-    get_word(w,pc);
-    getglobal(w);
-   }
-   break;
-
-   case PUSHINDEXED:
-    pushsubscript();
-    break;
-
-   case PUSHSELF:
-   {
-     TObject receiver = *(top-1);
-     Word w;
-     get_word(w,pc);
-     *top = func->consts[w];
-     incr_top;
-     pushsubscript();
-     *top = receiver;
-     incr_top;
-     break;
-   }
-
-   case PUSHCONSTANTB: {
-     *top = func->consts[*pc++];
-     incr_top;
-     break;
-   }
-
-   case PUSHCONSTANT: {
-     Word w;
-     get_word(w,pc);
-     *top = func->consts[w];
-     incr_top;
-     break;
-   }
-
-   case STORELOCAL0: case STORELOCAL1: case STORELOCAL2:
-   case STORELOCAL3: case STORELOCAL4: case STORELOCAL5:
-   case STORELOCAL6: case STORELOCAL7: case STORELOCAL8:
-   case STORELOCAL9:
-     *((stack+base) + (int)(opcode-STORELOCAL0)) = *(--top);
-     break;
-
-   case STORELOCAL: *((stack+base) + (*pc++)) = *(--top); break;
-
-   case STOREGLOBAL:
-   {
-    Word w;
-    get_word(w,pc);
-    setglobal(w);
-   }
-   break;
-
-   case STOREINDEXED0:
-    storesubscript(top-3, 1);
-    break;
-
-   case STOREINDEXED: {
-     int n = *pc++;
-     storesubscript(top-3-n, 2);
-     break;
-   }
-
-   case STORELIST0:
-   case STORELIST:
-   {
-    int m, n;
-    TObject *arr;
-    if (opcode == STORELIST0) m = 0;
-    else m = *(pc++) * FIELDS_PER_FLUSH;
-    n = *(pc++);
-    arr = top-n-1;
-    while (n)
-    {
-     ttype(top) = LUA_T_NUMBER; nvalue(top) = n+m;
-     *(lua_hashdefine (avalue(arr), top)) = *(top-1);
-     top--;
-     n--;
-    }
-   }
-   break;
-
-   case STOREMAP: {
-     int n = *(pc++);
-     TObject *arr = top-(2*n)-1;
-     while (n--) {
-       *(lua_hashdefine (avalue(arr), top-2)) = *(top-1);
-       top-=2;
-     }
-   }
-   break;
-
-   case ADJUST0:
-     adjust_top(base);
-     break;
-
-   case ADJUST: {
-     StkId newtop = base + *(pc++);
-     adjust_top(newtop);
-     break;
-   }
-
-   case VARARGS:
-     adjust_varargs(base + *(pc++));
-     break;
-
-   case CREATEARRAY:
-   {
-    Word size;
-    get_word(size,pc);
-    avalue(top) = lua_createarray(size);
-    ttype(top) = LUA_T_ARRAY;
-    incr_top;
-   }
-   break;
-
-   case EQOP:
-   {
-    int res = lua_equalObj(top-2, top-1);
-    --top;
-    ttype(top-1) = res ? LUA_T_NUMBER : LUA_T_NIL;
-    nvalue(top-1) = 1;
-   }
-   break;
-
-    case LTOP:
-      comparison(LUA_T_NUMBER, LUA_T_NIL, LUA_T_NIL, IM_LT);
-      break;
-
-   case LEOP:
-      comparison(LUA_T_NUMBER, LUA_T_NUMBER, LUA_T_NIL, IM_LE);
-      break;
-
-   case GTOP:
-      comparison(LUA_T_NIL, LUA_T_NIL, LUA_T_NUMBER, IM_GT);
-      break;
-
-   case GEOP:
-      comparison(LUA_T_NIL, LUA_T_NUMBER, LUA_T_NUMBER, IM_GE);
-      break;
-
-   case ADDOP:
-   {
-    TObject *l = top-2;
-    TObject *r = top-1;
-    if (tonumber(r) || tonumber(l))
-      call_arith(IM_ADD);
-    else
-    {
-      nvalue(l) += nvalue(r);
-      --top;
-    }
-   }
-   break;
-
-   case SUBOP:
-   {
-    TObject *l = top-2;
-    TObject *r = top-1;
-    if (tonumber(r) || tonumber(l))
-      call_arith(IM_SUB);
-    else
-    {
-      nvalue(l) -= nvalue(r);
-      --top;
-    }
-   }
-   break;
-
-   case MULTOP:
-   {
-    TObject *l = top-2;
-    TObject *r = top-1;
-    if (tonumber(r) || tonumber(l))
-      call_arith(IM_MUL);
-    else
-    {
-      nvalue(l) *= nvalue(r);
-      --top;
-    }
-   }
-   break;
-
-   case DIVOP:
-   {
-    TObject *l = top-2;
-    TObject *r = top-1;
-    if (tonumber(r) || tonumber(l))
-      call_arith(IM_DIV);
-    else
-    {
-      nvalue(l) /= nvalue(r);
-      --top;
-    }
-   }
-   break;
-
-   case POWOP:
-    call_arith(IM_POW);
-    break;
-
-   case CONCOP: {
-     TObject *l = top-2;
-     TObject *r = top-1;
-     if (tostring(l) || tostring(r))
-       call_binTM(IM_CONCAT, "unexpected type for concatenation");
-     else {
-       tsvalue(l) = luaI_createstring(lua_strconc(svalue(l),svalue(r)));
-       --top;
-     }
-   }
-   break;
-
-   case MINUSOP:
-    if (tonumber(top-1))
-    {
-      ttype(top) = LUA_T_NIL;
-      incr_top;
-      call_arith(IM_UNM);
-    }
-    else
-      nvalue(top-1) = - nvalue(top-1);
-   break;
-
-   case NOTOP:
-    ttype(top-1) = (ttype(top-1) == LUA_T_NIL) ? LUA_T_NUMBER : LUA_T_NIL;
-    nvalue(top-1) = 1;
-   break;
-
-   case ONTJMP:
-   {
-    Word w;
-    get_word(w,pc);
-    if (ttype(top-1) != LUA_T_NIL) pc += w;
-    else top--;
-   }
-   break;
-
-   case ONFJMP:
-   {
-    Word w;
-    get_word(w,pc);
-    if (ttype(top-1) == LUA_T_NIL) pc += w;
-    else top--;
-   }
-   break;
-
-   case JMP:
-   {
-    Word w;
-    get_word(w,pc);
-    pc += w;
-   }
-   break;
-
-   case UPJMP:
-   {
-    Word w;
-    get_word(w,pc);
-    pc -= w;
-   }
-   break;
-
-   case IFFJMP:
-   {
-    Word w;
-    get_word(w,pc);
-    top--;
-    if (ttype(top) == LUA_T_NIL) pc += w;
-   }
-   break;
-
-   case IFFUPJMP:
-   {
-    Word w;
-    get_word(w,pc);
-    top--;
-    if (ttype(top) == LUA_T_NIL) pc -= w;
-   }
-   break;
-
-   case CALLFUNC:
-   {
-     int nParams = *(pc++);
-     int nResults = *(pc++);
-     StkId newBase = (top-stack)-nParams;
-     do_call(newBase, nResults);
-   }
-   break;
-
-   case RETCODE0:
-   case RETCODE:
-     if (lua_callhook)
-       callHook (base, LUA_T_MARK, 1);
-     return (base + ((opcode==RETCODE0) ? 0 : *pc));
-
-   case SETLINE:
-   {
-    Word line;
-    get_word(line,pc);
-    if ((stack+base-1)->ttype != LUA_T_LINE)
-    {
-      /* open space for LINE value */
-      open_stack((top-stack)-base);
-      base++;
-      (stack+base-1)->ttype = LUA_T_LINE;
-    }
-    (stack+base-1)->value.i = line;
-    if (lua_linehook)
-      lineHook (line);
-    break;
-   }
-
-   default:
-    lua_error ("internal error - opcode doesn't match");
-  }
- }
-}
-
-
-#if LUA_COMPAT2_5
-/*
-** API: set a function as a fallback
-*/
-lua_Object lua_setfallback (char *name, lua_CFunction fallback)
-{
-  lua_pushstring(name);
-  lua_pushcfunction(fallback);
-  do_unprotectedrun(luaI_setfallback, 2, 1);
-  return put_luaObjectonTop();
-}
-#endif