static void closegoto(LexState *ls, int g, Labeldesc *label)
{
int i;
FuncState *fs = ls->fs;
Labellist *gl = &ls->dyd->gt;
Labeldesc *gt = &gl->arr[g];
lua_assert(luaS_eqstr(gt->name, label->name));
if (gt->nactvar < label->nactvar)
{
TString *vname = getlocvar(fs, gt->nactvar)->varname;
const char *msg = luaO_pushfstring(ls->L,
"<goto %s> at line %d jumps into the scope of local " LUA_QS,
getstr(gt->name), gt->line, getstr(vname));
semerror(ls, msg);
}
luaK_patchlist(fs, gt->pc, label->pc);
/* remove goto from pending list */
for (i = g; i < gl->n - 1; i++)
gl->arr[i] = gl->arr[i + 1];
gl->n--;
}
static int searchvar (FuncState *fs, TString *n) {
int i;
for (i = cast_int(fs->nactvar) - 1; i >= 0; i--) {
if (luaS_eqstr(n, getlocvar(fs, i)->varname))
return i;
}
return -1; /* not found */
}
static int searchupvalue (FuncState *fs, TString *name) {
int i;
Upvaldesc *up = fs->f->upvalues;
for (i = 0; i < fs->nups; i++) {
if (luaS_eqstr(up[i].name, name)) return i;
}
return -1; /* not found */
}
/*
** check whether new label 'lb' matches any pending gotos in current
** block; solves forward jumps
*/
static void findgotos (LexState *ls, Labeldesc *lb) {
Labellist *gl = &ls->dyd->gt;
int i = ls->fs->bl->firstgoto;
while (i < gl->n) {
if (luaS_eqstr(gl->arr[i].name, lb->name))
closegoto(ls, i, lb);
else
i++;
}
}
/*
** 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 (luaS_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 */
}
