| // Copyright 2012-2014 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 self::Context::*; |
| |
| use session::Session; |
| |
| use syntax::codemap::Span; |
| use rustc_front::intravisit::{self, Visitor}; |
| use rustc_front::hir; |
| |
| #[derive(Clone, Copy, PartialEq)] |
| enum Context { |
| Normal, Loop, Closure |
| } |
| |
| #[derive(Copy, Clone)] |
| struct CheckLoopVisitor<'a> { |
| sess: &'a Session, |
| cx: Context |
| } |
| |
| pub fn check_crate(sess: &Session, krate: &hir::Crate) { |
| krate.visit_all_items(&mut CheckLoopVisitor { sess: sess, cx: Normal }); |
| } |
| |
| impl<'a, 'v> Visitor<'v> for CheckLoopVisitor<'a> { |
| fn visit_item(&mut self, i: &hir::Item) { |
| self.with_context(Normal, |v| intravisit::walk_item(v, i)); |
| } |
| |
| fn visit_expr(&mut self, e: &hir::Expr) { |
| match e.node { |
| hir::ExprWhile(ref e, ref b, _) => { |
| self.visit_expr(&**e); |
| self.with_context(Loop, |v| v.visit_block(&**b)); |
| } |
| hir::ExprLoop(ref b, _) => { |
| self.with_context(Loop, |v| v.visit_block(&**b)); |
| } |
| hir::ExprClosure(_, _, ref b) => { |
| self.with_context(Closure, |v| v.visit_block(&**b)); |
| } |
| hir::ExprBreak(_) => self.require_loop("break", e.span), |
| hir::ExprAgain(_) => self.require_loop("continue", e.span), |
| _ => intravisit::walk_expr(self, e) |
| } |
| } |
| } |
| |
| impl<'a> CheckLoopVisitor<'a> { |
| fn with_context<F>(&mut self, cx: Context, f: F) where |
| F: FnOnce(&mut CheckLoopVisitor<'a>), |
| { |
| let old_cx = self.cx; |
| self.cx = cx; |
| f(self); |
| self.cx = old_cx; |
| } |
| |
| fn require_loop(&self, name: &str, span: Span) { |
| match self.cx { |
| Loop => {} |
| Closure => { |
| span_err!(self.sess, span, E0267, |
| "`{}` inside of a closure", name); |
| } |
| Normal => { |
| span_err!(self.sess, span, E0268, |
| "`{}` outside of loop", name); |
| } |
| } |
| } |
| } |