/*** $Id: lfunc.c,v 2.12.1.2 2007/12/28 14:58:43 roberto Exp $** Auxiliary functions to manipulate prototypes and closures** See Copyright Notice in lua.h*/#include <stddef.h>#define lfunc_c#define LUA_CORE#include "lua.h"#include "lfunc.h"#include "lgc.h"#include "lmem.h"#include "lobject.h"#include "lstate.h"Closure *luaF_newCclosure (lua_State *L, int nelems, Table *e) {  Closure *c = cast(Closure *, luaM_malloc(L, sizeCclosure(nelems)));  luaC_link(L, obj2gco(c), LUA_TFUNCTION);  c->c.isC = 1;  c->c.env = e;  c->c.nupvalues = cast_byte(nelems);  return c;}Closure *luaF_newLclosure (lua_State *L, int nelems, Table *e) {  Closure *c = cast(Closure *, luaM_malloc(L, sizeLclosure(nelems)));  luaC_link(L, obj2gco(c), LUA_TFUNCTION);  c->l.isC = 0;  c->l.env = e;  c->l.nupvalues = cast_byte(nelems);  while (nelems--) c->l.upvals[nelems] = NULL;  return c;}UpVal *luaF_newupval (lua_State *L) {  UpVal *uv = luaM_new(L, UpVal);  luaC_link(L, obj2gco(uv), LUA_TUPVAL);  uv->v = &uv->u.value;  setnilvalue(uv->v);  return uv;}UpVal *luaF_findupval (lua_State *L, StkId level) {  global_State *g = G(L);  GCObject **pp = &L->openupval;  UpVal *p;  UpVal *uv;  while (*pp != NULL && (p = ngcotouv(*pp))->v >= level) {    lua_assert(p->v != &p->u.value);    if (p->v == level) {  /* found a corresponding upvalue? */      if (isdead(g, obj2gco(p)))  /* is it dead? */        changewhite(obj2gco(p));  /* ressurect it */      return p;    }    pp = &p->next;  }  uv = luaM_new(L, UpVal);  /* not found: create a new one */  uv->tt = LUA_TUPVAL;  uv->marked = luaC_white(g);  uv->v = level;  /* current value lives in the stack */  uv->next = *pp;  /* chain it in the proper position */  *pp = obj2gco(uv);  uv->u.l.prev = &g->uvhead;  /* double link it in `uvhead' list */  uv->u.l.next = g->uvhead.u.l.next;  uv->u.l.next->u.l.prev = uv;  g->uvhead.u.l.next = uv;  lua_assert(uv->u.l.next->u.l.prev == uv && uv->u.l.prev->u.l.next == uv);  return uv;}static void unlinkupval (UpVal *uv) {  lua_assert(uv->u.l.next->u.l.prev == uv && uv->u.l.prev->u.l.next == uv);  uv->u.l.next->u.l.prev = uv->u.l.prev;  /* remove from `uvhead' list */  uv->u.l.prev->u.l.next = uv->u.l.next;}void luaF_freeupval (lua_State *L, UpVal *uv) {  if (uv->v != &uv->u.value)  /* is it open? */    unlinkupval(uv);  /* remove from open list */  luaM_free(L, uv);  /* free upvalue */}void luaF_close (lua_State *L, StkId level) {  UpVal *uv;  global_State *g = G(L);  while (L->openupval != NULL && (uv = ngcotouv(L->openupval))->v >= level) {    GCObject *o = obj2gco(uv);    lua_assert(!isblack(o) && uv->v != &uv->u.value);    L->openupval = uv->next;  /* remove from `open' list */    if (isdead(g, o))      luaF_freeupval(L, uv);  /* free upvalue */    else {      unlinkupval(uv);      setobj(L, &uv->u.value, uv->v);      uv->v = &uv->u.value;  /* now current value lives here */      luaC_linkupval(L, uv);  /* link upvalue into `gcroot' list */    }  }}Proto *luaF_newproto (lua_State *L) {  Proto *f = luaM_new(L, Proto);  luaC_link(L, obj2gco(f), LUA_TPROTO);  f->k = NULL;  f->sizek = 0;  f->p = NULL;  f->sizep = 0;  f->code = NULL;  f->sizecode = 0;  f->sizelineinfo = 0;  f->sizeupvalues = 0;  f->nups = 0;  f->upvalues = NULL;  f->numparams = 0;  f->is_vararg = 0;  f->maxstacksize = 0;  f->lineinfo = NULL;  f->sizelocvars = 0;  f->locvars = NULL;  f->linedefined = 0;  f->lastlinedefined = 0;  f->source = NULL;  return f;}void luaF_freeproto (lua_State *L, Proto *f) {  luaM_freearray(L, f->code, f->sizecode, Instruction);  luaM_freearray(L, f->p, f->sizep, Proto *);  luaM_freearray(L, f->k, f->sizek, TValue);  luaM_freearray(L, f->lineinfo, f->sizelineinfo, int);  luaM_freearray(L, f->locvars, f->sizelocvars, struct LocVar);  luaM_freearray(L, f->upvalues, f->sizeupvalues, TString *);  luaM_free(L, f);}void luaF_freeclosure (lua_State *L, Closure *c) {  int size = (c->c.isC) ? sizeCclosure(c->c.nupvalues) :                          sizeLclosure(c->l.nupvalues);  luaM_freemem(L, c, size);}/*** Look for n-th local variable at line `line' in function `func'.** Returns NULL if not found.*/const char *luaF_getlocalname (const Proto *f, int local_number, int pc) {  int i;  for (i = 0; i<f->sizelocvars && f->locvars[i].startpc <= pc; i++) {    if (pc < f->locvars[i].endpc) {  /* is variable active? */      local_number--;      if (local_number == 0)        return getstr(f->locvars[i].varname);    }  }  return NULL;  /* not found */}