misc/liblua/lfunc.c
author nemo
Mon, 08 Dec 2014 09:35:14 -0500
changeset 10634 35d059bd0932
parent 2812 0a24853de796
permissions -rw-r--r--
Use FreeAndNil across the board. Even if we are immediately assigning after, probably avoids accidental mistakes. Also free neglected owner tex on shutdown, and delete hog gears using the normal deletion procedure if for any reason they still exist (EndGame call?).

/*
** $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 */
}