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use middle::ty;
use syntax::ast::{Item, ItemImpl};
use syntax::ast;
use syntax::ast_util;
use syntax::visit;
use util::ppaux::UserString;
pub fn check(tcx: &ty::ctxt) {
let mut orphan = UnsafetyChecker { tcx: tcx };
visit::walk_crate(&mut orphan, tcx.map.krate());
}
struct UnsafetyChecker<'cx, 'tcx:'cx> {
tcx: &'cx ty::ctxt<'tcx>
}
impl<'cx, 'tcx,'v> visit::Visitor<'v> for UnsafetyChecker<'cx, 'tcx> {
fn visit_item(&mut self, item: &'v ast::Item) {
match item.node {
ast::ItemImpl(unsafety, _, _, _, _) => {
match ty::impl_trait_ref(self.tcx, ast_util::local_def(item.id)) {
None => {
match unsafety {
ast::Unsafety::Normal => { }
ast::Unsafety::Unsafe => {
self.tcx.sess.span_err(
item.span,
"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) {
(ast::Unsafety::Normal, ast::Unsafety::Unsafe) => {
self.tcx.sess.span_err(
item.span,
format!("implementing the trait `{}` is not unsafe",
trait_ref.user_string(self.tcx)).as_slice());
}
(ast::Unsafety::Unsafe, ast::Unsafety::Normal) => {
self.tcx.sess.span_err(
item.span,
format!("the trait `{}` requires an `unsafe impl` declaration",
trait_ref.user_string(self.tcx)).as_slice());
}
(ast::Unsafety::Unsafe, ast::Unsafety::Unsafe) |
(ast::Unsafety::Normal, ast::Unsafety::Normal) => {
}
}
}
}
}
_ => { }
}
visit::walk_item(self, item);
}
}