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use crate::traits::specialization_graph;
use crate::ty::fast_reject::{self, SimplifiedType, TreatParams};
use crate::ty::visit::TypeVisitable;
use crate::ty::{Ident, Ty, TyCtxt};
use hir::def_id::LOCAL_CRATE;
use rustc_hir as hir;
use rustc_hir::def_id::DefId;
use std::iter;
use rustc_data_structures::fx::FxIndexMap;
use rustc_errors::ErrorGuaranteed;
use rustc_macros::HashStable;
#[derive(HashStable, Encodable, Decodable)]
pub struct TraitDef {
pub def_id: DefId,
pub unsafety: hir::Unsafety,
pub paren_sugar: bool,
pub has_auto_impl: bool,
pub is_marker: bool,
pub skip_array_during_method_dispatch: bool,
pub specialization_kind: TraitSpecializationKind,
pub must_implement_one_of: Option<Box<[Ident]>>,
}
#[derive(HashStable, PartialEq, Clone, Copy, Encodable, Decodable)]
pub enum TraitSpecializationKind {
None,
Marker,
AlwaysApplicable,
}
#[derive(Default, Debug, HashStable)]
pub struct TraitImpls {
blanket_impls: Vec<DefId>,
non_blanket_impls: FxIndexMap<SimplifiedType, Vec<DefId>>,
}
impl TraitImpls {
pub fn blanket_impls(&self) -> &[DefId] {
self.blanket_impls.as_slice()
}
pub fn non_blanket_impls(&self) -> &FxIndexMap<SimplifiedType, Vec<DefId>> {
&self.non_blanket_impls
}
}
impl<'tcx> TraitDef {
pub fn new(
def_id: DefId,
unsafety: hir::Unsafety,
paren_sugar: bool,
has_auto_impl: bool,
is_marker: bool,
skip_array_during_method_dispatch: bool,
specialization_kind: TraitSpecializationKind,
must_implement_one_of: Option<Box<[Ident]>>,
) -> TraitDef {
TraitDef {
def_id,
unsafety,
paren_sugar,
has_auto_impl,
is_marker,
skip_array_during_method_dispatch,
specialization_kind,
must_implement_one_of,
}
}
pub fn ancestors(
&self,
tcx: TyCtxt<'tcx>,
of_impl: DefId,
) -> Result<specialization_graph::Ancestors<'tcx>, ErrorGuaranteed> {
specialization_graph::ancestors(tcx, self.def_id, of_impl)
}
}
impl<'tcx> TyCtxt<'tcx> {
pub fn for_each_impl<F: FnMut(DefId)>(self, def_id: DefId, mut f: F) {
let impls = self.trait_impls_of(def_id);
for &impl_def_id in impls.blanket_impls.iter() {
f(impl_def_id);
}
for v in impls.non_blanket_impls.values() {
for &impl_def_id in v {
f(impl_def_id);
}
}
}
pub fn for_each_relevant_impl<F: FnMut(DefId)>(
self,
def_id: DefId,
self_ty: Ty<'tcx>,
mut f: F,
) {
let _: Option<()> = self.find_map_relevant_impl(def_id, self_ty, |did| {
f(did);
None
});
}
pub fn non_blanket_impls_for_ty(
self,
def_id: DefId,
self_ty: Ty<'tcx>,
) -> impl Iterator<Item = DefId> + 'tcx {
let impls = self.trait_impls_of(def_id);
if let Some(simp) = fast_reject::simplify_type(self, self_ty, TreatParams::AsInfer) {
if let Some(impls) = impls.non_blanket_impls.get(&simp) {
return impls.iter().copied();
}
}
[].iter().copied()
}
pub fn find_map_relevant_impl<T, F: FnMut(DefId) -> Option<T>>(
self,
def_id: DefId,
self_ty: Ty<'tcx>,
mut f: F,
) -> Option<T> {
let impls = self.trait_impls_of(def_id);
for &impl_def_id in impls.blanket_impls.iter() {
if let result @ Some(_) = f(impl_def_id) {
return result;
}
}
if let Some(simp) = fast_reject::simplify_type(self, self_ty, TreatParams::AsPlaceholder) {
if let Some(impls) = impls.non_blanket_impls.get(&simp) {
for &impl_def_id in impls {
if let result @ Some(_) = f(impl_def_id) {
return result;
}
}
}
} else {
for &impl_def_id in impls.non_blanket_impls.values().flatten() {
if let result @ Some(_) = f(impl_def_id) {
return result;
}
}
}
None
}
pub fn all_impls(self, def_id: DefId) -> impl Iterator<Item = DefId> + 'tcx {
let TraitImpls { blanket_impls, non_blanket_impls } = self.trait_impls_of(def_id);
blanket_impls.iter().chain(non_blanket_impls.iter().flat_map(|(_, v)| v)).cloned()
}
}
pub(super) fn trait_impls_of_provider(tcx: TyCtxt<'_>, trait_id: DefId) -> TraitImpls {
let mut impls = TraitImpls::default();
if !trait_id.is_local() {
for &cnum in tcx.crates(()).iter() {
for &(impl_def_id, simplified_self_ty) in
tcx.implementations_of_trait((cnum, trait_id)).iter()
{
if let Some(simplified_self_ty) = simplified_self_ty {
impls
.non_blanket_impls
.entry(simplified_self_ty)
.or_default()
.push(impl_def_id);
} else {
impls.blanket_impls.push(impl_def_id);
}
}
}
}
for &impl_def_id in tcx.hir().trait_impls(trait_id) {
let impl_def_id = impl_def_id.to_def_id();
let impl_self_ty = tcx.type_of(impl_def_id);
if impl_self_ty.references_error() {
continue;
}
if let Some(simplified_self_ty) =
fast_reject::simplify_type(tcx, impl_self_ty, TreatParams::AsInfer)
{
impls.non_blanket_impls.entry(simplified_self_ty).or_default().push(impl_def_id);
} else {
impls.blanket_impls.push(impl_def_id);
}
}
impls
}
pub(super) fn incoherent_impls_provider(tcx: TyCtxt<'_>, simp: SimplifiedType) -> &[DefId] {
let mut impls = Vec::new();
for cnum in iter::once(LOCAL_CRATE).chain(tcx.crates(()).iter().copied()) {
for &impl_def_id in tcx.crate_incoherent_impls((cnum, simp)) {
impls.push(impl_def_id)
}
}
debug!(?impls);
tcx.arena.alloc_slice(&impls)
}