lvm.c

一个2D电磁场FEM计算的VC++源程序

/*
** $Id: lvm.c,v 1.146 2000/10/26 12:47:05 roberto Exp $
** Lua virtual machine
** See Copyright Notice in lua.h
*/


#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "lua.h"

#include "lapi.h"
#include "ldebug.h"
#include "ldo.h"
#include "lfunc.h"
#include "lgc.h"
#include "lobject.h"
#include "lopcodes.h"
#include "lstate.h"
#include "lstring.h"
#include "ltable.h"
#include "ltm.h"
#include "lvm.h"


#ifdef OLD_ANSI
#define strcoll(a,b)	strcmp(a,b)
#endif



/*
** Extra stack size to run a function:
** TAG_LINE(1), NAME(1), TM calls(3) (plus some extra...)
*/
#define	EXTRA_STACK	8



int luaV_tonumber (TObject *obj) {
  if (ttype(obj) != LUA_TSTRING)
    return 1;
  else {
    if (!luaO_str2d(svalue(obj), &nvalue(obj)))
      return 2;
    ttype(obj) = LUA_TNUMBER;
    return 0;
  }
}


int luaV_tostring (lua_State *L, TObject *obj) {  /* LUA_NUMBER */
  if (ttype(obj) != LUA_TNUMBER)
    return 1;
  else {
    char s[32];  /* 16 digits, sign, point and \0  (+ some extra...) */
    lua_number2str(s, nvalue(obj));  /* convert `s' to number */
    tsvalue(obj) = luaS_new(L, s);
    ttype(obj) = LUA_TSTRING;
    return 0;
  }
}


static void traceexec (lua_State *L, StkId base, StkId top, lua_Hook linehook) {
  CallInfo *ci = infovalue(base-1);
  int *lineinfo = ci->func->f.l->lineinfo;
  int pc = (*ci->pc - ci->func->f.l->code) - 1;
  int newline;
  if (pc == 0) {  /* may be first time? */
    ci->line = 1;
    ci->refi = 0;
    ci->lastpc = pc+1;  /* make sure it will call linehook */
  }
  newline = luaG_getline(lineinfo, pc, ci->line, &ci->refi);
  /* calls linehook when enters a new line or jumps back (loop) */
  if (newline != ci->line || pc <= ci->lastpc) {
    ci->line = newline;
    L->top = top;
    luaD_lineHook(L, base-1, newline, linehook);
  }
  ci->lastpc = pc;
}


static Closure *luaV_closure (lua_State *L, int nelems) {
  Closure *c = luaF_newclosure(L, nelems);
  L->top -= nelems;
  while (nelems--)
    c->upvalue[nelems] = *(L->top+nelems);
  clvalue(L->top) = c;
  ttype(L->top) = LUA_TFUNCTION;
  incr_top;
  return c;
}


void luaV_Cclosure (lua_State *L, lua_CFunction c, int nelems) {
  Closure *cl = luaV_closure(L, nelems);
  cl->f.c = c;
  cl->isC = 1;
}


void luaV_Lclosure (lua_State *L, Proto *l, int nelems) {
  Closure *cl = luaV_closure(L, nelems);
  cl->f.l = l;
  cl->isC = 0;
}


/*
** Function to index a table.
** Receives the table at `t' and the key at top.
*/
const TObject *luaV_gettable (lua_State *L, StkId t) {
  Closure *tm;
  int tg;
  if (ttype(t) == LUA_TTABLE &&  /* `t' is a table? */
      ((tg = hvalue(t)->htag) == LUA_TTABLE ||  /* with default tag? */
        luaT_gettm(L, tg, TM_GETTABLE) == NULL)) { /* or no TM? */
    /* do a primitive get */
    const TObject *h = luaH_get(L, hvalue(t), L->top-1);
    /* result is no nil or there is no `index' tag method? */
    if (ttype(h) != LUA_TNIL || ((tm=luaT_gettm(L, tg, TM_INDEX)) == NULL))
      return h;  /* return result */
    /* else call `index' tag method */
  }
  else {  /* try a `gettable' tag method */
    tm = luaT_gettmbyObj(L, t, TM_GETTABLE);
  }
  if (tm != NULL) {  /* is there a tag method? */
    luaD_checkstack(L, 2);
    *(L->top+1) = *(L->top-1);  /* key */
    *L->top = *t;  /* table */
    clvalue(L->top-1) = tm;  /* tag method */
    ttype(L->top-1) = LUA_TFUNCTION;
    L->top += 2;
    luaD_call(L, L->top - 3, 1);
    return L->top - 1;  /* call result */
  }
  else {  /* no tag method */
    luaG_typeerror(L, t, "index");
    return NULL;  /* to avoid warnings */
  }
}


/*
** Receives table at `t', key at `key' and value at top.
*/
void luaV_settable (lua_State *L, StkId t, StkId key) {
  int tg;
  if (ttype(t) == LUA_TTABLE &&  /* `t' is a table? */
      ((tg = hvalue(t)->htag) == LUA_TTABLE ||  /* with default tag? */
        luaT_gettm(L, tg, TM_SETTABLE) == NULL)) /* or no TM? */
    *luaH_set(L, hvalue(t), key) = *(L->top-1);  /* do a primitive set */
  else {  /* try a `settable' tag method */
    Closure *tm = luaT_gettmbyObj(L, t, TM_SETTABLE);
    if (tm != NULL) {
      luaD_checkstack(L, 3);
      *(L->top+2) = *(L->top-1);
      *(L->top+1) = *key;
      *(L->top) = *t;
      clvalue(L->top-1) = tm;
      ttype(L->top-1) = LUA_TFUNCTION;
      L->top += 3;
      luaD_call(L, L->top - 4, 0);  /* call `settable' tag method */
    }
    else  /* no tag method... */
      luaG_typeerror(L, t, "index");
  }
}


const TObject *luaV_getglobal (lua_State *L, TString *s) {
  const TObject *value = luaH_getstr(L->gt, s);
  Closure *tm = luaT_gettmbyObj(L, value, TM_GETGLOBAL);
  if (tm == NULL)  /* is there a tag method? */
    return value;  /* default behavior */
  else {  /* tag method */
    luaD_checkstack(L, 3);
    clvalue(L->top) = tm;
    ttype(L->top) = LUA_TFUNCTION;
    tsvalue(L->top+1) = s;  /* global name */
    ttype(L->top+1) = LUA_TSTRING;
    *(L->top+2) = *value;
    L->top += 3;
    luaD_call(L, L->top - 3, 1);
    return L->top - 1;
  }
}


void luaV_setglobal (lua_State *L, TString *s) {
  const TObject *oldvalue = luaH_getstr(L->gt, s);
  Closure *tm = luaT_gettmbyObj(L, oldvalue, TM_SETGLOBAL);
  if (tm == NULL) {  /* is there a tag method? */
    if (oldvalue != &luaO_nilobject) {
      /* cast to remove `const' is OK, because `oldvalue' != luaO_nilobject */
      *(TObject *)oldvalue = *(L->top - 1);
    }
    else {
      TObject key;
      ttype(&key) = LUA_TSTRING;
      tsvalue(&key) = s;
      *luaH_set(L, L->gt, &key) = *(L->top - 1);
    }
  }
  else {
    luaD_checkstack(L, 3);
    *(L->top+2) = *(L->top-1);  /* new value */
    *(L->top+1) = *oldvalue;
    ttype(L->top) = LUA_TSTRING;
    tsvalue(L->top) = s;
    clvalue(L->top-1) = tm;
    ttype(L->top-1) = LUA_TFUNCTION;
    L->top += 3;
    luaD_call(L, L->top - 4, 0);
  }
}


static int call_binTM (lua_State *L, StkId top, TMS event) {
  /* try first operand */
  Closure *tm = luaT_gettmbyObj(L, top-2, event);
  L->top = top;
  if (tm == NULL) {
    tm = luaT_gettmbyObj(L, top-1, event);  /* try second operand */
    if (tm == NULL) {
      tm = luaT_gettm(L, 0, event);  /* try a `global' method */
      if (tm == NULL)
        return 0;  /* error */
    }
  }
  lua_pushstring(L, luaT_eventname[event]);
  luaD_callTM(L, tm, 3, 1);
  return 1;
}


static void call_arith (lua_State *L, StkId top, TMS event) {
  if (!call_binTM(L, top, event))
    luaG_binerror(L, top-2, LUA_TNUMBER, "perform arithmetic on");
}


static int luaV_strcomp (const TString *ls, const TString *rs) {
  const char *l = ls->str;
  size_t ll = ls->len;
  const char *r = rs->str;
  size_t lr = rs->len;
  for (;;) {
    int temp = strcoll(l, r);
    if (temp != 0) return temp;
    else {  /* strings are equal up to a '\0' */
      size_t len = strlen(l);  /* index of first '\0' in both strings */
      if (len == ll)  /* l is finished? */
        return (len == lr) ? 0 : -1;  /* l is equal or smaller than r */
      else if (len == lr)  /* r is finished? */
        return 1;  /* l is greater than r (because l is not finished) */
      /* both strings longer than `len'; go on comparing (after the '\0') */
      len++;
      l += len; ll -= len; r += len; lr -= len;
    }
  }
}


int luaV_lessthan (lua_State *L, const TObject *l, const TObject *r, StkId top) {
  if (ttype(l) == LUA_TNUMBER && ttype(r) == LUA_TNUMBER)
    return (nvalue(l) < nvalue(r));
  else if (ttype(l) == LUA_TSTRING && ttype(r) == LUA_TSTRING)
    return (luaV_strcomp(tsvalue(l), tsvalue(r)) < 0);
  else {  /* call TM */
    luaD_checkstack(L, 2);
    *top++ = *l;
    *top++ = *r;
    if (!call_binTM(L, top, TM_LT))
      luaG_ordererror(L, top-2);
    L->top--;
    return (ttype(L->top) != LUA_TNIL);
  }
}


void luaV_strconc (lua_State *L, int total, StkId top) {
  do {
    int n = 2;  /* number of elements handled in this pass (at least 2) */
    if (tostring(L, top-2) || tostring(L, top-1)) {
      if (!call_binTM(L, top, TM_CONCAT))
        luaG_binerror(L, top-2, LUA_TSTRING, "concat");
    }
    else if (tsvalue(top-1)->len > 0) {  /* if len=0, do nothing */
      /* at least two string values; get as many as possible */
      lint32 tl = (lint32)tsvalue(top-1)->len + 
                  (lint32)tsvalue(top-2)->len;
      char *buffer;
      int i;
      while (n < total && !tostring(L, top-n-1)) {  /* collect total length */
        tl += tsvalue(top-n-1)->len;
        n++;
      }
      if (tl > MAX_SIZET) lua_error(L, "string size overflow");
      buffer = luaO_openspace(L, tl);
      tl = 0;
      for (i=n; i>0; i--) {  /* concat all strings */
        size_t l = tsvalue(top-i)->len;
        memcpy(buffer+tl, tsvalue(top-i)->str, l);
        tl += l;
      }
      tsvalue(top-n) = luaS_newlstr(L, buffer, tl);
    }
    total -= n-1;  /* got `n' strings to create 1 new */
    top -= n-1;
  } while (total > 1);  /* repeat until only 1 result left */
}


static void luaV_pack (lua_State *L, StkId firstelem) {
  int i;
  Hash *htab = luaH_new(L, 0);
  for (i=0; firstelem+i<L->top; i++)
    *luaH_setint(L, htab, i+1) = *(firstelem+i);
  /* store counter in field `n' */
  luaH_setstrnum(L, htab, luaS_new(L, "n"), i);
  L->top = firstelem;  /* remove elements from the stack */
  ttype(L->top) = LUA_TTABLE;
  hvalue(L->top) = htab;
  incr_top;
}


static void adjust_varargs (lua_State *L, StkId base, int nfixargs) {
  int nvararg = (L->top-base) - nfixargs;
  if (nvararg < 0)
    luaD_adjusttop(L, base, nfixargs);
  luaV_pack(L, base+nfixargs);
}



#define dojump(pc, i)	{ int d = GETARG_S(i); pc += d; }

/*
** Executes the given Lua function. Parameters are between [base,top).
** Returns n such that the the results are between [n,top).
*/
StkId luaV_execute (lua_State *L, const Closure *cl, StkId base) {
  const Proto *const tf = cl->f.l;
  StkId top;  /* keep top local, for performance */
  const Instruction *pc = tf->code;
  TString **const kstr = tf->kstr;
  const lua_Hook linehook = L->linehook;