static void leaveblock(FuncState *fs)
{
BlockCnt *bl = fs->bl;
LexState *ls = fs->ls;
if (bl->previous && bl->upval)
{
/* create a 'jump to here' to close upvalues */
int j = luaK_jump(fs);
luaK_patchclose(fs, j, bl->nactvar);
luaK_patchtohere(fs, j);
}
if (bl->isloop)
breaklabel(ls); /* close pending breaks */
fs->bl = bl->previous;
removevars(fs, bl->nactvar);
lua_assert(bl->nactvar == fs->nactvar);
fs->freereg = fs->nactvar; /* free registers */
ls->dyd->label.n = bl->firstlabel; /* remove local labels */
if (bl->previous) /* inner block? */
movegotosout(fs, bl); /* update pending gotos to outer block */
else if (bl->firstgoto < ls->dyd->gt.n) /* pending gotos in outer block? */
undefgoto(ls, &ls->dyd->gt.arr[bl->firstgoto]); /* error */
}
/*
** export pending gotos to outer level, to check them against
** outer labels; if the block being exited has upvalues, and
** the goto exits the scope of any variable (which can be the
** upvalue), close those variables being exited.
*/
static void movegotosout (FuncState *fs, BlockCnt *bl) {
int i = bl->firstgoto;
Labellist *gl = &fs->ls->dyd->gt;
/* correct pending gotos to current block and try to close it
with visible labels */
while (i < gl->n) {
Labeldesc *gt = &gl->arr[i];
if (gt->nactvar > bl->nactvar) {
if (bl->upval)
luaK_patchclose(fs, gt->pc, bl->nactvar);
gt->nactvar = bl->nactvar;
}
if (!findlabel(fs->ls, i))
i++; /* move to next one */
}
}
/*
** try to close a goto with existing labels; this solves backward jumps
*/
static int findlabel (LexState *ls, int g) {
int i;
BlockCnt *bl = ls->fs->bl;
Dyndata *dyd = ls->dyd;
Labeldesc *gt = &dyd->gt.arr[g];
/* check labels in current block for a match */
for (i = bl->firstlabel; i < dyd->label.n; i++) {
Labeldesc *lb = &dyd->label.arr[i];
if (eqstr(lb->name, gt->name)) { /* correct label? */
if (gt->nactvar > lb->nactvar &&
(bl->upval || dyd->label.n > bl->firstlabel))
luaK_patchclose(ls->fs, gt->pc, lb->nactvar);
closegoto(ls, g, lb); /* close it */
return 1;
}
}
return 0; /* label not found; cannot close goto */
}
/*static*/ void FuncState::leaveblock (/*FuncState *fs*/) {
//BlockCnt *bl = fs->bl;
//LexState *ls = fs->ls;
if (bl->previous && bl->upval) {
/* create a 'jump to here' to close upvalues */
int j = luaK_jump();
luaK_patchclose(j, bl->nactvar);
luaK_patchtohere(j);
}
if (bl->isloop)
ls->breaklabel(); /* close pending breaks */
bl = bl->previous;
removevars(bl->nactvar);
lua_assert(bl->nactvar == nactvar);
free_reg = nactvar; /* free registers */
ls->dyd->label.n = bl->firstlabel; /* remove local labels */
if (bl->previous) /* inner block? */
movegotosout(bl); /* update pending gotos to outer block */
else if (bl->firstgoto < ls->dyd->gt.n) /* pending gotos in outer block? */
ls->undefgoto(&ls->dyd->gt.arr[bl->firstgoto]); /* error */
}
