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