lua/lfunc.c

99 lines
1.9 KiB
C

/*
** $Id: lfunc.c,v 1.9 1998/06/19 16:14:09 roberto Exp roberto $
** Auxiliary functions to manipulate prototypes and closures
** See Copyright Notice in lua.h
*/
#include <stdlib.h>
#include "lfunc.h"
#include "lmem.h"
#include "lstate.h"
#define gcsizeproto(p) 5 /* approximate "weight" for a prototype */
#define gcsizeclosure(c) 1 /* approximate "weight" for a closure */
Closure *luaF_newclosure (int nelems)
{
Closure *c = (Closure *)luaM_malloc(sizeof(Closure)+nelems*sizeof(TObject));
luaO_insertlist(&(L->rootcl), (GCnode *)c);
L->nblocks += gcsizeclosure(c);
c->nelems = nelems;
return c;
}
TProtoFunc *luaF_newproto (void)
{
TProtoFunc *f = luaM_new(TProtoFunc);
f->code = NULL;
f->lineDefined = 0;
f->source = NULL;
f->consts = NULL;
f->nconsts = 0;
f->locvars = NULL;
luaO_insertlist(&(L->rootproto), (GCnode *)f);
L->nblocks += gcsizeproto(f);
return f;
}
static void freefunc (TProtoFunc *f)
{
luaM_free(f->code);
luaM_free(f->locvars);
luaM_free(f->consts);
luaM_free(f);
}
void luaF_freeproto (TProtoFunc *l)
{
while (l) {
TProtoFunc *next = (TProtoFunc *)l->head.next;
L->nblocks -= gcsizeproto(l);
freefunc(l);
l = next;
}
}
void luaF_freeclosure (Closure *l)
{
while (l) {
Closure *next = (Closure *)l->head.next;
L->nblocks -= gcsizeclosure(l);
luaM_free(l);
l = next;
}
}
/*
** Look for n-th local variable at line "line" in function "func".
** Returns NULL if not found.
*/
char *luaF_getlocalname (TProtoFunc *func, int local_number, int line)
{
int count = 0;
char *varname = NULL;
LocVar *lv = func->locvars;
if (lv == NULL)
return NULL;
for (; lv->line != -1 && lv->line < line; lv++) {
if (lv->varname) { /* register */
if (++count == local_number)
varname = lv->varname->str;
}
else /* unregister */
if (--count < local_number)
varname = NULL;
}
return varname;
}