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use rustc::dep_graph::DepNode;
use rustc::hir::def_id::DefId;
use rustc::hir;
use rustc::hir::itemlikevisit::ItemLikeVisitor;
use rustc::lint;
use rustc::traits::{self, Reveal};
use rustc::ty::{self, TyCtxt};
use syntax::ast;
use syntax_pos::Span;
struct InherentCollect<'a, 'tcx: 'a> {
tcx: TyCtxt<'a, 'tcx, 'tcx>
}
impl<'a, 'tcx, 'v> ItemLikeVisitor<'v> for InherentCollect<'a, 'tcx> {
fn visit_item(&mut self, item: &hir::Item) {
let (unsafety, ty) = match item.node {
hir::ItemImpl(unsafety, .., None, ref ty, _) => (unsafety, ty),
_ => return
};
match unsafety {
hir::Unsafety::Normal => {
}
hir::Unsafety::Unsafe => {
span_err!(self.tcx.sess,
item.span,
E0197,
"inherent impls cannot be declared as unsafe");
}
}
let def_id = self.tcx.hir.local_def_id(item.id);
let self_ty = self.tcx.item_type(def_id);
match self_ty.sty {
ty::TyAdt(def, _) => {
self.check_def_id(item, def.did);
}
ty::TyDynamic(ref data, ..) if data.principal().is_some() => {
self.check_def_id(item, data.principal().unwrap().def_id());
}
ty::TyChar => {
self.check_primitive_impl(def_id,
self.tcx.lang_items.char_impl(),
"char",
"char",
item.span);
}
ty::TyStr => {
self.check_primitive_impl(def_id,
self.tcx.lang_items.str_impl(),
"str",
"str",
item.span);
}
ty::TySlice(_) => {
self.check_primitive_impl(def_id,
self.tcx.lang_items.slice_impl(),
"slice",
"[T]",
item.span);
}
ty::TyRawPtr(ty::TypeAndMut { ty: _, mutbl: hir::MutImmutable }) => {
self.check_primitive_impl(def_id,
self.tcx.lang_items.const_ptr_impl(),
"const_ptr",
"*const T",
item.span);
}
ty::TyRawPtr(ty::TypeAndMut { ty: _, mutbl: hir::MutMutable }) => {
self.check_primitive_impl(def_id,
self.tcx.lang_items.mut_ptr_impl(),
"mut_ptr",
"*mut T",
item.span);
}
ty::TyInt(ast::IntTy::I8) => {
self.check_primitive_impl(def_id,
self.tcx.lang_items.i8_impl(),
"i8",
"i8",
item.span);
}
ty::TyInt(ast::IntTy::I16) => {
self.check_primitive_impl(def_id,
self.tcx.lang_items.i16_impl(),
"i16",
"i16",
item.span);
}
ty::TyInt(ast::IntTy::I32) => {
self.check_primitive_impl(def_id,
self.tcx.lang_items.i32_impl(),
"i32",
"i32",
item.span);
}
ty::TyInt(ast::IntTy::I64) => {
self.check_primitive_impl(def_id,
self.tcx.lang_items.i64_impl(),
"i64",
"i64",
item.span);
}
ty::TyInt(ast::IntTy::I128) => {
self.check_primitive_impl(def_id,
self.tcx.lang_items.i128_impl(),
"i128",
"i128",
item.span);
}
ty::TyInt(ast::IntTy::Is) => {
self.check_primitive_impl(def_id,
self.tcx.lang_items.isize_impl(),
"isize",
"isize",
item.span);
}
ty::TyUint(ast::UintTy::U8) => {
self.check_primitive_impl(def_id,
self.tcx.lang_items.u8_impl(),
"u8",
"u8",
item.span);
}
ty::TyUint(ast::UintTy::U16) => {
self.check_primitive_impl(def_id,
self.tcx.lang_items.u16_impl(),
"u16",
"u16",
item.span);
}
ty::TyUint(ast::UintTy::U32) => {
self.check_primitive_impl(def_id,
self.tcx.lang_items.u32_impl(),
"u32",
"u32",
item.span);
}
ty::TyUint(ast::UintTy::U64) => {
self.check_primitive_impl(def_id,
self.tcx.lang_items.u64_impl(),
"u64",
"u64",
item.span);
}
ty::TyUint(ast::UintTy::U128) => {
self.check_primitive_impl(def_id,
self.tcx.lang_items.u128_impl(),
"u128",
"u128",
item.span);
}
ty::TyUint(ast::UintTy::Us) => {
self.check_primitive_impl(def_id,
self.tcx.lang_items.usize_impl(),
"usize",
"usize",
item.span);
}
ty::TyFloat(ast::FloatTy::F32) => {
self.check_primitive_impl(def_id,
self.tcx.lang_items.f32_impl(),
"f32",
"f32",
item.span);
}
ty::TyFloat(ast::FloatTy::F64) => {
self.check_primitive_impl(def_id,
self.tcx.lang_items.f64_impl(),
"f64",
"f64",
item.span);
}
ty::TyError => {
return;
}
_ => {
struct_span_err!(self.tcx.sess,
ty.span,
E0118,
"no base type found for inherent implementation")
.span_label(ty.span, &format!("impl requires a base type"))
.note(&format!("either implement a trait on it or create a newtype \
to wrap it instead"))
.emit();
return;
}
}
}
fn visit_trait_item(&mut self, _trait_item: &hir::TraitItem) {
}
fn visit_impl_item(&mut self, _impl_item: &hir::ImplItem) {
}
}
impl<'a, 'tcx> InherentCollect<'a, 'tcx> {
fn check_def_id(&self, item: &hir::Item, def_id: DefId) {
if def_id.is_local() {
let impl_def_id = self.tcx.hir.local_def_id(item.id);
self.tcx.maps.inherent_impls.borrow_mut().push(def_id, impl_def_id);
} else {
struct_span_err!(self.tcx.sess,
item.span,
E0116,
"cannot define inherent `impl` for a type outside of the crate \
where the type is defined")
.span_label(item.span,
&format!("impl for type defined outside of crate."))
.note("define and implement a trait or new type instead")
.emit();
}
}
fn check_primitive_impl(&self,
impl_def_id: DefId,
lang_def_id: Option<DefId>,
lang: &str,
ty: &str,
span: Span) {
match lang_def_id {
Some(lang_def_id) if lang_def_id == impl_def_id => {
}
_ => {
struct_span_err!(self.tcx.sess,
span,
E0390,
"only a single inherent implementation marked with `#[lang = \
\"{}\"]` is allowed for the `{}` primitive",
lang,
ty)
.span_help(span, "consider using a trait to implement these methods")
.emit();
}
}
}
}
struct InherentOverlapChecker<'a, 'tcx: 'a> {
tcx: TyCtxt<'a, 'tcx, 'tcx>
}
impl<'a, 'tcx> InherentOverlapChecker<'a, 'tcx> {
fn check_for_common_items_in_impls(&self, impl1: DefId, impl2: DefId) {
#[derive(Copy, Clone, PartialEq)]
enum Namespace {
Type,
Value,
}
let name_and_namespace = |def_id| {
let item = self.tcx.associated_item(def_id);
(item.name, match item.kind {
ty::AssociatedKind::Type => Namespace::Type,
ty::AssociatedKind::Const |
ty::AssociatedKind::Method => Namespace::Value,
})
};
let impl_items1 = self.tcx.associated_item_def_ids(impl1);
let impl_items2 = self.tcx.associated_item_def_ids(impl2);
for &item1 in &impl_items1[..] {
let (name, namespace) = name_and_namespace(item1);
for &item2 in &impl_items2[..] {
if (name, namespace) == name_and_namespace(item2) {
let msg = format!("duplicate definitions with name `{}`", name);
let node_id = self.tcx.hir.as_local_node_id(item1).unwrap();
self.tcx.sess.add_lint(lint::builtin::OVERLAPPING_INHERENT_IMPLS,
node_id,
self.tcx.span_of_impl(item1).unwrap(),
msg);
}
}
}
}
fn check_for_overlapping_inherent_impls(&self, ty_def_id: DefId) {
let _task = self.tcx.dep_graph.in_task(DepNode::CoherenceOverlapInherentCheck(ty_def_id));
let inherent_impls = self.tcx.maps.inherent_impls.borrow();
let impls = match inherent_impls.get(&ty_def_id) {
Some(impls) => impls,
None => return,
};
for (i, &impl1_def_id) in impls.iter().enumerate() {
for &impl2_def_id in &impls[(i + 1)..] {
self.tcx.infer_ctxt((), Reveal::UserFacing).enter(|infcx| {
if traits::overlapping_impls(&infcx, impl1_def_id, impl2_def_id).is_some() {
self.check_for_common_items_in_impls(impl1_def_id, impl2_def_id)
}
});
}
}
}
}
impl<'a, 'tcx, 'v> ItemLikeVisitor<'v> for InherentOverlapChecker<'a, 'tcx> {
fn visit_item(&mut self, item: &'v hir::Item) {
match item.node {
hir::ItemEnum(..) |
hir::ItemStruct(..) |
hir::ItemTrait(..) |
hir::ItemUnion(..) => {
let type_def_id = self.tcx.hir.local_def_id(item.id);
self.check_for_overlapping_inherent_impls(type_def_id);
}
_ => {}
}
}
fn visit_trait_item(&mut self, _trait_item: &hir::TraitItem) {
}
fn visit_impl_item(&mut self, _impl_item: &hir::ImplItem) {
}
}
pub fn check<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) {
tcx.visit_all_item_likes_in_krate(DepNode::CoherenceCheckImpl,
&mut InherentCollect { tcx });
tcx.visit_all_item_likes_in_krate(DepNode::CoherenceOverlapCheckSpecial,
&mut InherentOverlapChecker { tcx });
}