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Check trait unsafety for defaulted traits

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This commit is contained in:
Flavio Percoco 2015-03-11 18:53:55 -05:00
parent 01d24297eb
commit 38dbcb2e37
3 changed files with 67 additions and 46 deletions
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4
src/libcore/marker.rs
View file

@ -39,7 +39,7 @@ pub unsafe trait Send : MarkerTrait {
// empty.
}
impl Send for .. { }
unsafe impl Send for .. { }
impl<T> !Send for *const T { }
impl<T> !Send for *mut T { }
@ -205,7 +205,7 @@ pub unsafe trait Sync : MarkerTrait {
// Empty
}
impl Sync for .. { }
unsafe impl Sync for .. { }
impl<T> !Sync for *const T { }
impl<T> !Sync for *mut T { }

99
src/librustc_typeck/coherence/unsafety.rs
View file

@ -27,54 +27,65 @@ struct UnsafetyChecker<'cx, 'tcx:'cx> {
tcx: &'cx ty::ctxt<'tcx>
}
impl<'cx, 'tcx, 'v> UnsafetyChecker<'cx, 'tcx> {
fn check_unsafety_coherence(&mut self, item: &'v ast::Item,
unsafety: ast::Unsafety,
polarity: ast::ImplPolarity) {
match ty::impl_trait_ref(self.tcx, ast_util::local_def(item.id)) {
None => {
// Inherent impl.
match unsafety {
ast::Unsafety::Normal => { /* OK */ }
ast::Unsafety::Unsafe => {
span_err!(self.tcx.sess, item.span, E0197,
"inherent impls cannot be declared as unsafe");
}
}
}
Some(trait_ref) => {
let trait_def = ty::lookup_trait_def(self.tcx, trait_ref.def_id);
match (trait_def.unsafety, unsafety, polarity) {
(ast::Unsafety::Unsafe,
ast::Unsafety::Unsafe, ast::ImplPolarity::Negative) => {
span_err!(self.tcx.sess, item.span, E0198,
"negative implementations are not unsafe");
}
(ast::Unsafety::Normal, ast::Unsafety::Unsafe, _) => {
span_err!(self.tcx.sess, item.span, E0199,
"implementing the trait `{}` is not unsafe",
trait_ref.user_string(self.tcx));
}
(ast::Unsafety::Unsafe,
ast::Unsafety::Normal, ast::ImplPolarity::Positive) => {
span_err!(self.tcx.sess, item.span, E0200,
"the trait `{}` requires an `unsafe impl` declaration",
trait_ref.user_string(self.tcx));
}
(ast::Unsafety::Unsafe,
ast::Unsafety::Normal, ast::ImplPolarity::Negative) |
(ast::Unsafety::Unsafe,
ast::Unsafety::Unsafe, ast::ImplPolarity::Positive) |
(ast::Unsafety::Normal, ast::Unsafety::Normal, _) => {
/* OK */
}
}
}
}
}
}
impl<'cx, 'tcx,'v> visit::Visitor<'v> for UnsafetyChecker<'cx, 'tcx> {
fn visit_item(&mut self, item: &'v ast::Item) {
match item.node {
ast::ItemDefaultImpl(unsafety, _) => {
self.check_unsafety_coherence(item, unsafety, ast::ImplPolarity::Positive);
}
ast::ItemImpl(unsafety, polarity, _, _, _, _) => {
match ty::impl_trait_ref(self.tcx, ast_util::local_def(item.id)) {
None => {
// Inherent impl.
match unsafety {
ast::Unsafety::Normal => { /* OK */ }
ast::Unsafety::Unsafe => {
span_err!(self.tcx.sess, item.span, E0197,
"inherent impls cannot be declared as unsafe");
}
}
}
Some(trait_ref) => {
let trait_def = ty::lookup_trait_def(self.tcx, trait_ref.def_id);
match (trait_def.unsafety, unsafety, polarity) {
(ast::Unsafety::Unsafe,
ast::Unsafety::Unsafe, ast::ImplPolarity::Negative) => {
span_err!(self.tcx.sess, item.span, E0198,
"negative implementations are not unsafe");
}
(ast::Unsafety::Normal, ast::Unsafety::Unsafe, _) => {
span_err!(self.tcx.sess, item.span, E0199,
"implementing the trait `{}` is not unsafe",
trait_ref.user_string(self.tcx));
}
(ast::Unsafety::Unsafe,
ast::Unsafety::Normal, ast::ImplPolarity::Positive) => {
span_err!(self.tcx.sess, item.span, E0200,
"the trait `{}` requires an `unsafe impl` declaration",
trait_ref.user_string(self.tcx));
}
(ast::Unsafety::Unsafe,
ast::Unsafety::Normal, ast::ImplPolarity::Negative) |
(ast::Unsafety::Unsafe,
ast::Unsafety::Unsafe, ast::ImplPolarity::Positive) |
(ast::Unsafety::Normal, ast::Unsafety::Normal, _) => {
/* OK */
}
}
}
}
self.check_unsafety_coherence(item, unsafety, polarity);
}
_ => { }
}

10
src/test/compile-fail/coherence-default-trait-impl.rs
View file

@ -21,4 +21,14 @@ impl MyTrait for .. {}
impl MyTrait for .. {}
//~^ ERROR conflicting implementations for trait `MyTrait`
trait MySafeTrait: MarkerTrait {}
unsafe impl MySafeTrait for .. {}
//~^ ERROR implementing the trait `MySafeTrait` is not unsafe
unsafe trait MyUnsafeTrait: MarkerTrait {}
impl MyUnsafeTrait for .. {}
//~^ ERROR the trait `MyUnsafeTrait` requires an `unsafe impl` declaration
fn main() {}