// 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 or the MIT license // , 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; type ctx = {in_loop: bool, can_ret: bool}; fn check_crate(tcx: ty::ctxt, crate: @crate) { visit::visit_crate(*crate, {in_loop: false, can_ret: true}, visit::mk_vt(@{ visit_item: |i, _cx, v| { visit::visit_item(i, {in_loop: false, can_ret: true}, v); }, visit_expr: |e: @expr, cx: ctx, v: visit::vt| { match e.node { expr_while(e, ref b) => { (v.visit_expr)(e, cx, v); (v.visit_block)((*b), {in_loop: true,.. cx}, v); } expr_loop(ref b, _) => { (v.visit_block)((*b), {in_loop: true,.. cx}, v); } expr_fn(_, _, _, _) => { visit::visit_expr(e, {in_loop: false, can_ret: true}, v); } expr_fn_block(_, ref b, _) => { (v.visit_block)((*b), {in_loop: false, can_ret: false}, v); } expr_loop_body(@{node: expr_fn_block(_, ref b, _), _}) => { let proto = ty::ty_fn_proto(ty::expr_ty(tcx, e)); let blk = (proto == ProtoBorrowed); (v.visit_block)((*b), {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() })); }