static void retstat (LexState *ls) {
/* stat -> RETURN explist */
FuncState *fs = ls->fs;
expdesc e;
int first, nret; /* registers with returned values */
luaX_next(ls); /* skip RETURN */
if (block_follow(ls->t.token) || ls->t.token == ';')
first = nret = 0; /* return no values */
else {
nret = explist1(ls, &e); /* optional return values */
if (hasmultret(e.k)) {
luaK_setmultret(fs, &e);
if (e.k == VCALL && nret == 1) { /* tail call? */
SET_OPCODE(getcode(fs,&e), OP_TAILCALL);
lua_assert(GETARG_A(getcode(fs,&e)) == fs->nactvar);
}
first = fs->nactvar;
nret = LUA_MULTRET; /* return all values */
}
else {
if (nret == 1) /* only one single value? */
first = luaK_exp2anyreg(fs, &e);
else {
luaK_exp2nextreg(fs, &e); /* values must go to the `stack' */
first = fs->nactvar; /* return all `active' values */
lua_assert(nret == fs->freereg - first);
}
}
}
luaK_ret(fs, first, nret);
}
static void chunk (LexState *ls) {
/* chunk -> { stat [`;'] } */
int islast = 0;
enterlevel(ls);
while (!islast && !block_follow(ls->t.token)) {
islast = statement(ls);
testnext(ls, ';');
lua_assert(ls->fs->freereg >= ls->fs->nactvar);
ls->fs->freereg = ls->fs->nactvar; /* free registers */
}
leavelevel(ls);
}
static void retstat (LexState *ls) {
/* stat -> RETURN explist */
FuncState *fs = ls->fs;
BlockCnt *bl = fs->bl;
expdesc e;
int first, nret; /* registers with returned values */
int ret_in_try = 0;
luaX_next(ls); /* skip RETURN */
if (block_follow(ls->t.token) || ls->t.token == ';')
first = nret = 0; /* return no values */
else {
nret = explist1(ls, &e); /* optional return values */
if (hasmultret(e.k)) {
luaK_setmultret(fs, &e);
if (e.k == VCALL && nret == 1) { /* tail call? */
SET_OPCODE(getcode(fs,&e), OP_TAILCALL);
lua_assert(GETARG_A(getcode(fs,&e)) == fs->nactvar);
}
first = fs->nactvar;
nret = LUA_MULTRET; /* return all values */
}
else {
if (nret == 1) /* only one single value? */
first = luaK_exp2anyreg(fs, &e);
else {
luaK_exp2nextreg(fs, &e); /* values must go to the `stack' */
first = fs->nactvar; /* return all `active' values */
lua_assert(nret == fs->freereg - first);
}
}
}
/* before return, we should exit all try-catch blocks */
while (bl) {
if (bl->isbreakable == 2) {
if (ret_in_try)
luaK_codeABC(fs, OP_EXITTRY, 0, 0, 0);
else {
ret_in_try = 1;
luaK_codeABC(fs, OP_EXITTRY, first, nret+1, 1); /* here we will save all return values */
}
} else if (bl->isbreakable == 3)
luaX_syntaxerror(ls, "can't return in _finally_ clause");
bl = bl->previous;
}
luaK_codeABC(fs, OP_RETURN, first, nret+1, ret_in_try);
}
static void chunk (LexState *ls)
{
/* chunk -> { stat [`;'] } */
int islast = 0;
callstack_ref cref( *ls->L );
while (!islast && !block_follow(ls->t.token))
{
islast = statement(ls);
testnext(ls, ';');
FuncState *fs = GetCurrentFuncState( ls );
lua_assert(fs->f->maxstacksize >= fs->freereg && fs->freereg >= fs->nactvar);
fs->freereg = fs->nactvar; /* free registers */
}
}
