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// 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_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()
}));
}
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