use rustc_infer::infer::TyCtxtInferExt;
use rustc_lint::LateContext;
use rustc_middle::ty::subst::{GenericArg, GenericArgKind};
-use rustc_middle::ty::{self, AdtDef, IntTy, Ty, 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;
}
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)
// exists and has the desired signature. Unfortunately FnCtxt is not exported
// so we can't use its `lookup_method` method.
let into_iter_collections: &[Symbol] = &[
- sym::vec_type,
- sym::option_type,
- sym::result_type,
+ sym::Vec,
+ sym::Option,
+ sym::Result,
sym::BTreeMap,
sym::BTreeSet,
- sym::vecdeque_type,
+ sym::VecDeque,
sym::LinkedList,
sym::BinaryHeap,
- sym::hashset_type,
- sym::hashmap_type,
+ sym::HashSet,
+ sym::HashMap,
sym::PathBuf,
sym::Path,
sym::Receiver,
/// 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`.
+///
+/// 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>,
ty::Tuple(substs) => substs.types().any(|ty| is_must_use_ty(cx, ty)),
ty::Opaque(ref def_id, _) => {
for (predicate, _) in cx.tcx.explicit_item_bounds(*def_id) {
- if let ty::PredicateKind::Trait(trait_predicate, _) = predicate.kind().skip_binder() {
+ if let ty::PredicateKind::Trait(trait_predicate) = predicate.kind().skip_binder() {
if must_use_attr(cx.tcx.get_attrs(trait_predicate.trait_ref.def_id)).is_some() {
return true;
}
}
// FIXME: Per https://doc.rust-lang.org/nightly/nightly-rustc/rustc_trait_selection/infer/at/struct.At.html#method.normalize
-// this function can be removed once the `normalizie` method does not panic when normalization does
+// this function can be removed once the `normalize` method does not panic when normalization does
// not succeed
/// Checks if `Ty` is normalizable. This function is useful
/// to avoid crashes on `layout_of`.
result
}
-/// Returns true iff the given type is a primitive (a bool or char, any integer or floating-point
-/// number type, a str, or an array, slice, or tuple of those types).
+/// Returns `true` if the given type is a non aggregate primitive (a `bool` or `char`, any
+/// integer or floating-point number type). For checking aggregation of primitive types (e.g.
+/// tuples and slices of primitive type) see `is_recursively_primitive_type`
+pub fn is_non_aggregate_primitive_type(ty: Ty<'_>) -> bool {
+ matches!(ty.kind(), ty::Bool | ty::Char | ty::Int(_) | ty::Uint(_) | ty::Float(_))
+}
+
+/// Returns `true` if the given type is a primitive (a `bool` or `char`, any integer or
+/// floating-point number type, a `str`, or an array, slice, or tuple of those types).
pub fn is_recursively_primitive_type(ty: Ty<'_>) -> bool {
match ty.kind() {
ty::Bool | ty::Char | ty::Int(_) | ty::Uint(_) | ty::Float(_) | ty::Str => true,
}
}
-/// 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 {
_ => a == b,
}
}
+
+/// Checks if a given type looks safe to be uninitialized.
+pub fn is_uninit_value_valid_for_ty(cx: &LateContext<'_>, ty: Ty<'_>) -> bool {
+ match ty.kind() {
+ ty::Array(component, _) => is_uninit_value_valid_for_ty(cx, component),
+ ty::Tuple(types) => types.types().all(|ty| is_uninit_value_valid_for_ty(cx, ty)),
+ ty::Adt(adt, _) => cx.tcx.lang_items().maybe_uninit() == Some(adt.did),
+ _ => 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