/*
** $Id$
** Auxiliary functions to manipulate prototypes and closures
** See Copyright Notice in lua.h
*/



#include "engine/lua/lfunc.h"
#include "engine/lua/lmem.h"
#include "engine/lua/lstate.h"

#define gcsizeproto(p)	5  /* approximate "weight" for a prototype */
#define gcsizeclosure(c) 1  /* approximate "weight" for a closure */



Closure *luaF_newclosure(int32 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() {
	TProtoFunc *f = luaM_new(TProtoFunc);
	f->code = NULL;
	f->lineDefined = 0;
	f->fileName = 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, int32 local_number, int32 line) {
	int32 count = 0;
	char *varname = NULL;
	LocVar *lv = func->locvars;
	if (!lv)
		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;
}