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