83 lines
3.0 KiB
Rust
83 lines
3.0 KiB
Rust
// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
|
|
// file at the top-level directory of this distribution and at
|
|
// http://rust-lang.org/COPYRIGHT.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
|
|
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
|
|
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
|
|
// option. This file may not be copied, modified, or distributed
|
|
// except according to those terms.
|
|
|
|
|
|
use middle::ty;
|
|
|
|
use syntax::ast::*;
|
|
use syntax::visit;
|
|
|
|
pub struct Context {
|
|
in_loop: bool,
|
|
can_ret: bool
|
|
}
|
|
|
|
pub fn check_crate(tcx: ty::ctxt, crate: @crate) {
|
|
visit::visit_crate(*crate,
|
|
Context { in_loop: false, can_ret: true },
|
|
visit::mk_vt(@visit::Visitor {
|
|
visit_item: |i, _cx, v| {
|
|
visit::visit_item(i, Context {
|
|
in_loop: false,
|
|
can_ret: true
|
|
}, v);
|
|
},
|
|
visit_expr: |e: @expr, cx: Context, v: visit::vt<Context>| {
|
|
match e.node {
|
|
expr_while(e, ref b) => {
|
|
(v.visit_expr)(e, cx, v);
|
|
(v.visit_block)((*b), Context { in_loop: true,.. cx }, v);
|
|
}
|
|
expr_loop(ref b, _) => {
|
|
(v.visit_block)((*b), Context { in_loop: true,.. cx }, v);
|
|
}
|
|
expr_fn(*) => {
|
|
visit::visit_expr(e, Context {
|
|
in_loop: false,
|
|
can_ret: true
|
|
}, v);
|
|
}
|
|
expr_fn_block(_, ref b) => {
|
|
(v.visit_block)((*b), Context {
|
|
in_loop: false,
|
|
can_ret: false
|
|
}, v);
|
|
}
|
|
expr_loop_body(@expr {node: expr_fn_block(_, ref b), _}) => {
|
|
let sigil = ty::ty_closure_sigil(ty::expr_ty(tcx, e));
|
|
let blk = (sigil == BorrowedSigil);
|
|
(v.visit_block)((*b), Context {
|
|
in_loop: true,
|
|
can_ret: blk
|
|
}, v);
|
|
}
|
|
expr_break(_) => {
|
|
if !cx.in_loop {
|
|
tcx.sess.span_err(e.span, ~"`break` outside of loop");
|
|
}
|
|
}
|
|
expr_again(_) => {
|
|
if !cx.in_loop {
|
|
tcx.sess.span_err(e.span, ~"`again` outside of loop");
|
|
}
|
|
}
|
|
expr_ret(oe) => {
|
|
if !cx.can_ret {
|
|
tcx.sess.span_err(e.span, ~"`return` in block function");
|
|
}
|
|
visit::visit_expr_opt(oe, cx, v);
|
|
}
|
|
_ => visit::visit_expr(e, cx, v)
|
|
}
|
|
},
|
|
.. *visit::default_visitor()
|
|
}));
|
|
}
|