use rustc_infer::infer::TyCtxtInferExt;
use rustc_lint::LateContext;
use rustc_middle::ty::subst::{GenericArg, GenericArgKind};
-use rustc_middle::ty::{self, AdtDef, IntTy, Ty, TyCtxt, TypeFoldable, UintTy};
-use rustc_span::sym;
-use rustc_span::symbol::{Ident, Symbol};
-use rustc_span::DUMMY_SP;
+use rustc_middle::ty::{self, AdtDef, IntTy, Predicate, Ty, TyCtxt, TypeFoldable, UintTy};
+use rustc_span::symbol::Ident;
+use rustc_span::{sym, Span, Symbol, DUMMY_SP};
use rustc_trait_selection::infer::InferCtxtExt;
use rustc_trait_selection::traits::query::normalize::AtExt;
+use std::iter;
use crate::{match_def_path, must_use_attr};
+// Checks if the given type implements copy.
pub fn is_copy<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
ty.is_copy_modulo_regions(cx.tcx.at(DUMMY_SP), cx.param_env)
}
/// Checks whether a type can be partially moved.
-pub fn can_partially_move_ty(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
+pub fn can_partially_move_ty<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
if has_drop(cx, ty) || is_copy(cx, ty) {
return false;
}
}
/// Walks into `ty` and returns `true` if any inner type is the same as `other_ty`
-pub fn contains_ty<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>, other_ty: Ty<'tcx>) -> bool {
- ty.walk(tcx).any(|inner| match inner.unpack() {
+pub fn contains_ty(ty: Ty<'_>, other_ty: Ty<'_>) -> bool {
+ ty.walk().any(|inner| match inner.unpack() {
GenericArgKind::Type(inner_ty) => ty::TyS::same_type(other_ty, inner_ty),
GenericArgKind::Lifetime(_) | GenericArgKind::Const(_) => false,
})
/// Walks into `ty` and returns `true` if any inner type is an instance of the given adt
/// constructor.
-pub fn contains_adt_constructor<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>, adt: &'tcx AdtDef) -> bool {
- ty.walk(tcx).any(|inner| match inner.unpack() {
+pub fn contains_adt_constructor(ty: Ty<'_>, adt: &AdtDef) -> bool {
+ ty.walk().any(|inner| match inner.unpack() {
GenericArgKind::Type(inner_ty) => inner_ty.ty_adt_def() == Some(adt),
GenericArgKind::Lifetime(_) | GenericArgKind::Const(_) => false,
})
pub fn get_iterator_item_ty<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> Option<Ty<'tcx>> {
cx.tcx
.get_diagnostic_item(sym::Iterator)
- .and_then(|iter_did| {
- cx.tcx.associated_items(iter_did).find_by_name_and_kind(
- cx.tcx,
- Ident::from_str("Item"),
- ty::AssocKind::Type,
- iter_did,
- )
- })
+ .and_then(|iter_did| get_associated_type(cx, ty, iter_did, "Item"))
+}
+
+/// Returns the associated type `name` for `ty` as an implementation of `trait_id`.
+/// Do not invoke without first verifying that the type implements the trait.
+pub fn get_associated_type<'tcx>(
+ cx: &LateContext<'tcx>,
+ ty: Ty<'tcx>,
+ trait_id: DefId,
+ name: &str,
+) -> Option<Ty<'tcx>> {
+ cx.tcx
+ .associated_items(trait_id)
+ .find_by_name_and_kind(cx.tcx, Ident::from_str(name), ty::AssocKind::Type, trait_id)
.map(|assoc| {
let proj = cx.tcx.mk_projection(assoc.def_id, cx.tcx.mk_substs_trait(ty, &[]));
cx.tcx.normalize_erasing_regions(cx.param_env, proj)
/// Checks whether a type implements a trait.
/// The function returns false in case the type contains an inference variable.
-/// See also [`get_trait_def_id`](super::get_trait_def_id).
+///
+/// See:
+/// * [`get_trait_def_id`](super::get_trait_def_id) to get a trait [`DefId`].
+/// * [Common tools for writing lints] for an example how to use this function and other options.
+///
+/// [Common tools for writing lints]: https://github.com/rust-lang/rust-clippy/blob/master/doc/common_tools_writing_lints.md#checking-if-a-type-implements-a-specific-trait
pub fn implements_trait<'tcx>(
cx: &LateContext<'tcx>,
ty: Ty<'tcx>,
.iter()
.all(|field| is_normalizable_helper(cx, param_env, field.ty(cx.tcx, substs), cache))
}),
- _ => ty.walk(cx.tcx).all(|generic_arg| match generic_arg.unpack() {
+ _ => ty.walk().all(|generic_arg| match generic_arg.unpack() {
GenericArgKind::Type(inner_ty) if inner_ty != ty => {
is_normalizable_helper(cx, param_env, inner_ty, cache)
},
}
}
-/// Checks if the type is equal to a diagnostic item
+/// Checks if the type is equal to a diagnostic item. To check if a type implements a
+/// trait marked with a diagnostic item use [`implements_trait`].
+///
+/// For a further exploitation what diagnostic items are see [diagnostic items] in
+/// rustc-dev-guide.
+///
+/// ---
///
/// If you change the signature, remember to update the internal lint `MatchTypeOnDiagItem`
+///
+/// [Diagnostic Items]: https://rustc-dev-guide.rust-lang.org/diagnostics/diagnostic-items.html
pub fn is_type_diagnostic_item(cx: &LateContext<'_>, ty: Ty<'_>, diag_item: Symbol) -> bool {
match ty.kind() {
ty::Adt(adt, _) => cx.tcx.is_diagnostic_item(diag_item, adt.did),
/// Returns `true` if types `a` and `b` are same types having same `Const` generic args,
/// otherwise returns `false`
-pub fn same_type_and_consts(a: Ty<'tcx>, b: Ty<'tcx>) -> bool {
+pub fn same_type_and_consts<'tcx>(a: Ty<'tcx>, b: Ty<'tcx>) -> bool {
match (&a.kind(), &b.kind()) {
(&ty::Adt(did_a, substs_a), &ty::Adt(did_b, substs_b)) => {
if did_a != did_b {
_ => false,
}
}
+
+/// Gets an iterator over all predicates which apply to the given item.
+pub fn all_predicates_of(tcx: TyCtxt<'_>, id: DefId) -> impl Iterator<Item = &(Predicate<'_>, Span)> {
+ let mut next_id = Some(id);
+ iter::from_fn(move || {
+ next_id.take().map(|id| {
+ let preds = tcx.predicates_of(id);
+ next_id = preds.parent;
+ preds.predicates.iter()
+ })
+ })
+ .flatten()
+}
projects / rust.git / blobdiff