| // Copyright 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. |
| |
| //! Unsafety checker: every impl either implements a trait defined in this |
| //! crate or pertains to a type defined in this crate. |
| |
| use rustc::ty::TyCtxt; |
| use rustc::hir::itemlikevisit::ItemLikeVisitor; |
| use rustc::hir::{self, Unsafety}; |
| |
| pub fn check<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) { |
| let mut unsafety = UnsafetyChecker { tcx: tcx }; |
| tcx.hir.krate().visit_all_item_likes(&mut unsafety); |
| } |
| |
| struct UnsafetyChecker<'cx, 'tcx: 'cx> { |
| tcx: TyCtxt<'cx, 'tcx, 'tcx>, |
| } |
| |
| impl<'cx, 'tcx, 'v> UnsafetyChecker<'cx, 'tcx> { |
| fn check_unsafety_coherence(&mut self, |
| item: &'v hir::Item, |
| impl_generics: Option<&hir::Generics>, |
| unsafety: hir::Unsafety, |
| polarity: hir::ImplPolarity) { |
| match self.tcx.impl_trait_ref(self.tcx.hir.local_def_id(item.id)) { |
| None => {} |
| |
| Some(trait_ref) => { |
| let trait_def = self.tcx.trait_def(trait_ref.def_id); |
| let unsafe_attr = impl_generics.and_then(|g| g.carries_unsafe_attr()); |
| match (trait_def.unsafety, unsafe_attr, unsafety, polarity) { |
| (_, _, Unsafety::Unsafe, hir::ImplPolarity::Negative) => { |
| span_err!(self.tcx.sess, |
| item.span, |
| E0198, |
| "negative implementations are not unsafe"); |
| } |
| |
| (Unsafety::Normal, None, Unsafety::Unsafe, _) => { |
| span_err!(self.tcx.sess, |
| item.span, |
| E0199, |
| "implementing the trait `{}` is not unsafe", |
| trait_ref); |
| } |
| |
| (Unsafety::Unsafe, _, Unsafety::Normal, hir::ImplPolarity::Positive) => { |
| span_err!(self.tcx.sess, |
| item.span, |
| E0200, |
| "the trait `{}` requires an `unsafe impl` declaration", |
| trait_ref); |
| } |
| |
| (Unsafety::Normal, Some(g), Unsafety::Normal, hir::ImplPolarity::Positive) => |
| { |
| span_err!(self.tcx.sess, |
| item.span, |
| E0569, |
| "requires an `unsafe impl` declaration due to `#[{}]` attribute", |
| g.attr_name()); |
| } |
| |
| (_, _, Unsafety::Normal, hir::ImplPolarity::Negative) | |
| (Unsafety::Unsafe, _, Unsafety::Unsafe, hir::ImplPolarity::Positive) | |
| (Unsafety::Normal, Some(_), Unsafety::Unsafe, hir::ImplPolarity::Positive) | |
| (Unsafety::Normal, None, Unsafety::Normal, _) => { |
| // OK |
| } |
| } |
| } |
| } |
| } |
| } |
| |
| impl<'cx, 'tcx, 'v> ItemLikeVisitor<'v> for UnsafetyChecker<'cx, 'tcx> { |
| fn visit_item(&mut self, item: &'v hir::Item) { |
| match item.node { |
| hir::ItemImpl(unsafety, polarity, _, ref generics, ..) => { |
| self.check_unsafety_coherence(item, Some(generics), unsafety, polarity); |
| } |
| _ => {} |
| } |
| } |
| |
| fn visit_trait_item(&mut self, _trait_item: &hir::TraitItem) { |
| } |
| |
| fn visit_impl_item(&mut self, _impl_item: &hir::ImplItem) { |
| } |
| } |