792 lines
30 KiB
Rust
792 lines
30 KiB
Rust
//! Util methods for [`rustc_middle::ty`]
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#![allow(clippy::module_name_repetitions)]
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use core::ops::ControlFlow;
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use rustc_ast::ast::Mutability;
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use rustc_data_structures::fx::{FxHashMap, FxHashSet};
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use rustc_hir as hir;
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use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res};
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use rustc_hir::def_id::DefId;
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use rustc_hir::{Expr, FnDecl, LangItem, TyKind, Unsafety};
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use rustc_infer::infer::TyCtxtInferExt;
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use rustc_lint::LateContext;
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use rustc_middle::mir::interpret::{ConstValue, Scalar};
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use rustc_middle::ty::subst::{GenericArg, GenericArgKind, Subst};
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use rustc_middle::ty::{
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self, AdtDef, Binder, BoundRegion, DefIdTree, FnSig, IntTy, ParamEnv, Predicate, PredicateKind, ProjectionTy,
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Region, RegionKind, Ty, TyCtxt, TypeFoldable, TypeSuperFoldable, TypeVisitor, UintTy, VariantDef, VariantDiscr,
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};
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use rustc_span::symbol::Ident;
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use rustc_span::{sym, Span, Symbol, DUMMY_SP};
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use rustc_target::abi::{Size, VariantIdx};
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use rustc_trait_selection::infer::InferCtxtExt;
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use rustc_trait_selection::traits::query::normalize::AtExt;
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use std::iter;
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use crate::{match_def_path, path_res, paths};
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// Checks if the given type implements copy.
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pub fn is_copy<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
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ty.is_copy_modulo_regions(cx.tcx.at(DUMMY_SP), cx.param_env)
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}
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/// Checks whether a type can be partially moved.
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pub fn can_partially_move_ty<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
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if has_drop(cx, ty) || is_copy(cx, ty) {
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return false;
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}
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match ty.kind() {
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ty::Param(_) => false,
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ty::Adt(def, subs) => def.all_fields().any(|f| !is_copy(cx, f.ty(cx.tcx, subs))),
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_ => true,
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}
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}
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/// Walks into `ty` and returns `true` if any inner type is the same as `other_ty`
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pub fn contains_ty<'tcx>(ty: Ty<'tcx>, other_ty: Ty<'tcx>) -> bool {
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ty.walk().any(|inner| match inner.unpack() {
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GenericArgKind::Type(inner_ty) => other_ty == inner_ty,
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GenericArgKind::Lifetime(_) | GenericArgKind::Const(_) => false,
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})
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}
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/// Walks into `ty` and returns `true` if any inner type is an instance of the given adt
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/// constructor.
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pub fn contains_adt_constructor<'tcx>(ty: Ty<'tcx>, adt: AdtDef<'tcx>) -> bool {
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ty.walk().any(|inner| match inner.unpack() {
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GenericArgKind::Type(inner_ty) => inner_ty.ty_adt_def() == Some(adt),
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GenericArgKind::Lifetime(_) | GenericArgKind::Const(_) => false,
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})
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}
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/// Resolves `<T as Iterator>::Item` for `T`
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/// Do not invoke without first verifying that the type implements `Iterator`
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pub fn get_iterator_item_ty<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> Option<Ty<'tcx>> {
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cx.tcx
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.get_diagnostic_item(sym::Iterator)
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.and_then(|iter_did| get_associated_type(cx, ty, iter_did, "Item"))
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}
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/// Returns the associated type `name` for `ty` as an implementation of `trait_id`.
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/// Do not invoke without first verifying that the type implements the trait.
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pub fn get_associated_type<'tcx>(
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cx: &LateContext<'tcx>,
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ty: Ty<'tcx>,
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trait_id: DefId,
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name: &str,
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) -> Option<Ty<'tcx>> {
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cx.tcx
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.associated_items(trait_id)
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.find_by_name_and_kind(cx.tcx, Ident::from_str(name), ty::AssocKind::Type, trait_id)
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.and_then(|assoc| {
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let proj = cx.tcx.mk_projection(assoc.def_id, cx.tcx.mk_substs_trait(ty, &[]));
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cx.tcx.try_normalize_erasing_regions(cx.param_env, proj).ok()
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})
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}
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/// Get the diagnostic name of a type, e.g. `sym::HashMap`. To check if a type
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/// implements a trait marked with a diagnostic item use [`implements_trait`].
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///
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/// For a further exploitation what diagnostic items are see [diagnostic items] in
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/// rustc-dev-guide.
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///
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/// [Diagnostic Items]: https://rustc-dev-guide.rust-lang.org/diagnostics/diagnostic-items.html
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pub fn get_type_diagnostic_name(cx: &LateContext<'_>, ty: Ty<'_>) -> Option<Symbol> {
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match ty.kind() {
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ty::Adt(adt, _) => cx.tcx.get_diagnostic_name(adt.did()),
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_ => None,
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}
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}
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/// Returns true if ty has `iter` or `iter_mut` methods
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pub fn has_iter_method(cx: &LateContext<'_>, probably_ref_ty: Ty<'_>) -> Option<Symbol> {
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// FIXME: instead of this hard-coded list, we should check if `<adt>::iter`
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// exists and has the desired signature. Unfortunately FnCtxt is not exported
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// so we can't use its `lookup_method` method.
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let into_iter_collections: &[Symbol] = &[
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sym::Vec,
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sym::Option,
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sym::Result,
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sym::BTreeMap,
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sym::BTreeSet,
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sym::VecDeque,
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sym::LinkedList,
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sym::BinaryHeap,
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sym::HashSet,
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sym::HashMap,
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sym::PathBuf,
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sym::Path,
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sym::Receiver,
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];
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let ty_to_check = match probably_ref_ty.kind() {
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ty::Ref(_, ty_to_check, _) => *ty_to_check,
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_ => probably_ref_ty,
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};
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let def_id = match ty_to_check.kind() {
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ty::Array(..) => return Some(sym::array),
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ty::Slice(..) => return Some(sym::slice),
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ty::Adt(adt, _) => adt.did(),
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_ => return None,
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};
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for &name in into_iter_collections {
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if cx.tcx.is_diagnostic_item(name, def_id) {
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return Some(cx.tcx.item_name(def_id));
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}
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}
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None
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}
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/// Checks whether a type implements a trait.
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/// The function returns false in case the type contains an inference variable.
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///
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/// See:
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/// * [`get_trait_def_id`](super::get_trait_def_id) to get a trait [`DefId`].
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/// * [Common tools for writing lints] for an example how to use this function and other options.
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///
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/// [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
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pub fn implements_trait<'tcx>(
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cx: &LateContext<'tcx>,
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ty: Ty<'tcx>,
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trait_id: DefId,
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ty_params: &[GenericArg<'tcx>],
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) -> bool {
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implements_trait_with_env(cx.tcx, cx.param_env, ty, trait_id, ty_params)
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}
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/// Same as `implements_trait` but allows using a `ParamEnv` different from the lint context.
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pub fn implements_trait_with_env<'tcx>(
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tcx: TyCtxt<'tcx>,
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param_env: ParamEnv<'tcx>,
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ty: Ty<'tcx>,
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trait_id: DefId,
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ty_params: &[GenericArg<'tcx>],
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) -> bool {
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// Clippy shouldn't have infer types
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assert!(!ty.needs_infer());
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let ty = tcx.erase_regions(ty);
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if ty.has_escaping_bound_vars() {
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return false;
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}
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let ty_params = tcx.mk_substs(ty_params.iter());
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tcx.infer_ctxt().enter(|infcx| {
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infcx
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.type_implements_trait(trait_id, ty, ty_params, param_env)
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.must_apply_modulo_regions()
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})
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}
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/// Checks whether this type implements `Drop`.
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pub fn has_drop<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
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match ty.ty_adt_def() {
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Some(def) => def.has_dtor(cx.tcx),
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None => false,
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}
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}
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// Returns whether the type has #[must_use] attribute
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pub fn is_must_use_ty<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
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match ty.kind() {
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ty::Adt(adt, _) => cx.tcx.has_attr(adt.did(), sym::must_use),
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ty::Foreign(did) => cx.tcx.has_attr(*did, sym::must_use),
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ty::Slice(ty) | ty::Array(ty, _) | ty::RawPtr(ty::TypeAndMut { ty, .. }) | ty::Ref(_, ty, _) => {
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// for the Array case we don't need to care for the len == 0 case
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// because we don't want to lint functions returning empty arrays
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is_must_use_ty(cx, *ty)
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},
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ty::Tuple(substs) => substs.iter().any(|ty| is_must_use_ty(cx, ty)),
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ty::Opaque(def_id, _) => {
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for (predicate, _) in cx.tcx.explicit_item_bounds(*def_id) {
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if let ty::PredicateKind::Trait(trait_predicate) = predicate.kind().skip_binder() {
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if cx.tcx.has_attr(trait_predicate.trait_ref.def_id, sym::must_use) {
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return true;
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}
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}
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}
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false
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},
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ty::Dynamic(binder, _) => {
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for predicate in binder.iter() {
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if let ty::ExistentialPredicate::Trait(ref trait_ref) = predicate.skip_binder() {
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if cx.tcx.has_attr(trait_ref.def_id, sym::must_use) {
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return true;
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}
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}
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}
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false
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},
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_ => false,
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}
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}
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// FIXME: Per https://doc.rust-lang.org/nightly/nightly-rustc/rustc_trait_selection/infer/at/struct.At.html#method.normalize
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// this function can be removed once the `normalize` method does not panic when normalization does
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// not succeed
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/// Checks if `Ty` is normalizable. This function is useful
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/// to avoid crashes on `layout_of`.
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pub fn is_normalizable<'tcx>(cx: &LateContext<'tcx>, param_env: ty::ParamEnv<'tcx>, ty: Ty<'tcx>) -> bool {
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is_normalizable_helper(cx, param_env, ty, &mut FxHashMap::default())
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}
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fn is_normalizable_helper<'tcx>(
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cx: &LateContext<'tcx>,
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param_env: ty::ParamEnv<'tcx>,
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ty: Ty<'tcx>,
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cache: &mut FxHashMap<Ty<'tcx>, bool>,
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) -> bool {
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if let Some(&cached_result) = cache.get(&ty) {
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return cached_result;
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}
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// prevent recursive loops, false-negative is better than endless loop leading to stack overflow
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cache.insert(ty, false);
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let result = cx.tcx.infer_ctxt().enter(|infcx| {
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let cause = rustc_middle::traits::ObligationCause::dummy();
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if infcx.at(&cause, param_env).normalize(ty).is_ok() {
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match ty.kind() {
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ty::Adt(def, substs) => def.variants().iter().all(|variant| {
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variant
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.fields
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.iter()
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.all(|field| is_normalizable_helper(cx, param_env, field.ty(cx.tcx, substs), cache))
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}),
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_ => ty.walk().all(|generic_arg| match generic_arg.unpack() {
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GenericArgKind::Type(inner_ty) if inner_ty != ty => {
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is_normalizable_helper(cx, param_env, inner_ty, cache)
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},
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_ => true, // if inner_ty == ty, we've already checked it
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}),
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}
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} else {
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false
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}
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});
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cache.insert(ty, result);
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result
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}
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/// Returns `true` if the given type is a non aggregate primitive (a `bool` or `char`, any
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/// integer or floating-point number type). For checking aggregation of primitive types (e.g.
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/// tuples and slices of primitive type) see `is_recursively_primitive_type`
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pub fn is_non_aggregate_primitive_type(ty: Ty<'_>) -> bool {
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matches!(ty.kind(), ty::Bool | ty::Char | ty::Int(_) | ty::Uint(_) | ty::Float(_))
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}
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/// Returns `true` if the given type is a primitive (a `bool` or `char`, any integer or
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/// floating-point number type, a `str`, or an array, slice, or tuple of those types).
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pub fn is_recursively_primitive_type(ty: Ty<'_>) -> bool {
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match *ty.kind() {
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ty::Bool | ty::Char | ty::Int(_) | ty::Uint(_) | ty::Float(_) | ty::Str => true,
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ty::Ref(_, inner, _) if *inner.kind() == ty::Str => true,
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ty::Array(inner_type, _) | ty::Slice(inner_type) => is_recursively_primitive_type(inner_type),
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ty::Tuple(inner_types) => inner_types.iter().all(is_recursively_primitive_type),
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_ => false,
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}
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}
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/// Checks if the type is a reference equals to a diagnostic item
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pub fn is_type_ref_to_diagnostic_item(cx: &LateContext<'_>, ty: Ty<'_>, diag_item: Symbol) -> bool {
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match ty.kind() {
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ty::Ref(_, ref_ty, _) => match ref_ty.kind() {
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ty::Adt(adt, _) => cx.tcx.is_diagnostic_item(diag_item, adt.did()),
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_ => false,
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},
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_ => false,
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}
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}
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/// Checks if the type is equal to a diagnostic item. To check if a type implements a
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/// trait marked with a diagnostic item use [`implements_trait`].
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///
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/// For a further exploitation what diagnostic items are see [diagnostic items] in
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/// rustc-dev-guide.
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///
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/// ---
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///
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/// If you change the signature, remember to update the internal lint `MatchTypeOnDiagItem`
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///
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/// [Diagnostic Items]: https://rustc-dev-guide.rust-lang.org/diagnostics/diagnostic-items.html
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pub fn is_type_diagnostic_item(cx: &LateContext<'_>, ty: Ty<'_>, diag_item: Symbol) -> bool {
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match ty.kind() {
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ty::Adt(adt, _) => cx.tcx.is_diagnostic_item(diag_item, adt.did()),
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_ => false,
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}
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}
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/// Checks if the type is equal to a lang item.
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///
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/// Returns `false` if the `LangItem` is not defined.
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pub fn is_type_lang_item(cx: &LateContext<'_>, ty: Ty<'_>, lang_item: hir::LangItem) -> bool {
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match ty.kind() {
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ty::Adt(adt, _) => cx
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.tcx
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.lang_items()
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.require(lang_item)
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.map_or(false, |li| li == adt.did()),
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_ => false,
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}
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}
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/// Return `true` if the passed `typ` is `isize` or `usize`.
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pub fn is_isize_or_usize(typ: Ty<'_>) -> bool {
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matches!(typ.kind(), ty::Int(IntTy::Isize) | ty::Uint(UintTy::Usize))
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}
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/// Checks if type is struct, enum or union type with the given def path.
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///
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/// If the type is a diagnostic item, use `is_type_diagnostic_item` instead.
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/// If you change the signature, remember to update the internal lint `MatchTypeOnDiagItem`
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pub fn match_type(cx: &LateContext<'_>, ty: Ty<'_>, path: &[&str]) -> bool {
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match ty.kind() {
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ty::Adt(adt, _) => match_def_path(cx, adt.did(), path),
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_ => false,
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}
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}
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/// Checks if the drop order for a type matters. Some std types implement drop solely to
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/// deallocate memory. For these types, and composites containing them, changing the drop order
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/// won't result in any observable side effects.
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pub fn needs_ordered_drop<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
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fn needs_ordered_drop_inner<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>, seen: &mut FxHashSet<Ty<'tcx>>) -> bool {
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if !seen.insert(ty) {
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return false;
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}
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if !ty.has_significant_drop(cx.tcx, cx.param_env) {
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false
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}
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// Check for std types which implement drop, but only for memory allocation.
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else if is_type_lang_item(cx, ty, LangItem::OwnedBox)
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|| matches!(
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get_type_diagnostic_name(cx, ty),
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Some(sym::HashSet | sym::Rc | sym::Arc | sym::cstring_type)
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)
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|| match_type(cx, ty, &paths::WEAK_RC)
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|| match_type(cx, ty, &paths::WEAK_ARC)
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{
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// Check all of the generic arguments.
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if let ty::Adt(_, subs) = ty.kind() {
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subs.types().any(|ty| needs_ordered_drop_inner(cx, ty, seen))
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} else {
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true
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}
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} else if !cx
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.tcx
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.lang_items()
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.drop_trait()
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.map_or(false, |id| implements_trait(cx, ty, id, &[]))
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{
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// This type doesn't implement drop, so no side effects here.
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// Check if any component type has any.
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match ty.kind() {
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ty::Tuple(fields) => fields.iter().any(|ty| needs_ordered_drop_inner(cx, ty, seen)),
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ty::Array(ty, _) => needs_ordered_drop_inner(cx, *ty, seen),
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ty::Adt(adt, subs) => adt
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.all_fields()
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.map(|f| f.ty(cx.tcx, subs))
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.any(|ty| needs_ordered_drop_inner(cx, ty, seen)),
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_ => true,
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}
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} else {
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true
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}
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}
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needs_ordered_drop_inner(cx, ty, &mut FxHashSet::default())
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}
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/// Peels off all references on the type. Returns the underlying type and the number of references
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/// removed.
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pub fn peel_mid_ty_refs(ty: Ty<'_>) -> (Ty<'_>, usize) {
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fn peel(ty: Ty<'_>, count: usize) -> (Ty<'_>, usize) {
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if let ty::Ref(_, ty, _) = ty.kind() {
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peel(*ty, count + 1)
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} else {
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(ty, count)
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}
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}
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peel(ty, 0)
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}
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/// Peels off all references on the type.Returns the underlying type, the number of references
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/// removed, and whether the pointer is ultimately mutable or not.
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pub fn peel_mid_ty_refs_is_mutable(ty: Ty<'_>) -> (Ty<'_>, usize, Mutability) {
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fn f(ty: Ty<'_>, count: usize, mutability: Mutability) -> (Ty<'_>, usize, Mutability) {
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match ty.kind() {
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ty::Ref(_, ty, Mutability::Mut) => f(*ty, count + 1, mutability),
|
|
ty::Ref(_, ty, Mutability::Not) => f(*ty, count + 1, Mutability::Not),
|
|
_ => (ty, count, mutability),
|
|
}
|
|
}
|
|
f(ty, 0, Mutability::Mut)
|
|
}
|
|
|
|
/// Returns `true` if the given type is an `unsafe` function.
|
|
pub fn type_is_unsafe_function<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
|
|
match ty.kind() {
|
|
ty::FnDef(..) | ty::FnPtr(_) => ty.fn_sig(cx.tcx).unsafety() == Unsafety::Unsafe,
|
|
_ => false,
|
|
}
|
|
}
|
|
|
|
/// Returns the base type for HIR references and pointers.
|
|
pub fn walk_ptrs_hir_ty<'tcx>(ty: &'tcx hir::Ty<'tcx>) -> &'tcx hir::Ty<'tcx> {
|
|
match ty.kind {
|
|
TyKind::Ptr(ref mut_ty) | TyKind::Rptr(_, ref mut_ty) => walk_ptrs_hir_ty(mut_ty.ty),
|
|
_ => ty,
|
|
}
|
|
}
|
|
|
|
/// Returns the base type for references and raw pointers, and count reference
|
|
/// depth.
|
|
pub fn walk_ptrs_ty_depth(ty: Ty<'_>) -> (Ty<'_>, usize) {
|
|
fn inner(ty: Ty<'_>, depth: usize) -> (Ty<'_>, usize) {
|
|
match ty.kind() {
|
|
ty::Ref(_, ty, _) => inner(*ty, depth + 1),
|
|
_ => (ty, depth),
|
|
}
|
|
}
|
|
inner(ty, 0)
|
|
}
|
|
|
|
/// Returns `true` if types `a` and `b` are same types having same `Const` generic args,
|
|
/// otherwise returns `false`
|
|
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 {
|
|
return false;
|
|
}
|
|
|
|
substs_a
|
|
.iter()
|
|
.zip(substs_b.iter())
|
|
.all(|(arg_a, arg_b)| match (arg_a.unpack(), arg_b.unpack()) {
|
|
(GenericArgKind::Const(inner_a), GenericArgKind::Const(inner_b)) => inner_a == inner_b,
|
|
(GenericArgKind::Type(type_a), GenericArgKind::Type(type_b)) => {
|
|
same_type_and_consts(type_a, type_b)
|
|
},
|
|
_ => true,
|
|
})
|
|
},
|
|
_ => 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.iter().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()
|
|
}
|
|
|
|
/// A signature for a function like type.
|
|
#[derive(Clone, Copy)]
|
|
pub enum ExprFnSig<'tcx> {
|
|
Sig(Binder<'tcx, FnSig<'tcx>>),
|
|
Closure(Option<&'tcx FnDecl<'tcx>>, Binder<'tcx, FnSig<'tcx>>),
|
|
Trait(Binder<'tcx, Ty<'tcx>>, Option<Binder<'tcx, Ty<'tcx>>>),
|
|
}
|
|
impl<'tcx> ExprFnSig<'tcx> {
|
|
/// Gets the argument type at the given offset. This will return `None` when the index is out of
|
|
/// bounds only for variadic functions, otherwise this will panic.
|
|
pub fn input(self, i: usize) -> Option<Binder<'tcx, Ty<'tcx>>> {
|
|
match self {
|
|
Self::Sig(sig) => {
|
|
if sig.c_variadic() {
|
|
sig.inputs().map_bound(|inputs| inputs.get(i).copied()).transpose()
|
|
} else {
|
|
Some(sig.input(i))
|
|
}
|
|
},
|
|
Self::Closure(_, sig) => Some(sig.input(0).map_bound(|ty| ty.tuple_fields()[i])),
|
|
Self::Trait(inputs, _) => Some(inputs.map_bound(|ty| ty.tuple_fields()[i])),
|
|
}
|
|
}
|
|
|
|
/// Gets the argument type at the given offset. For closures this will also get the type as
|
|
/// written. This will return `None` when the index is out of bounds only for variadic
|
|
/// functions, otherwise this will panic.
|
|
pub fn input_with_hir(self, i: usize) -> Option<(Option<&'tcx hir::Ty<'tcx>>, Binder<'tcx, Ty<'tcx>>)> {
|
|
match self {
|
|
Self::Sig(sig) => {
|
|
if sig.c_variadic() {
|
|
sig.inputs()
|
|
.map_bound(|inputs| inputs.get(i).copied())
|
|
.transpose()
|
|
.map(|arg| (None, arg))
|
|
} else {
|
|
Some((None, sig.input(i)))
|
|
}
|
|
},
|
|
Self::Closure(decl, sig) => Some((
|
|
decl.and_then(|decl| decl.inputs.get(i)),
|
|
sig.input(0).map_bound(|ty| ty.tuple_fields()[i]),
|
|
)),
|
|
Self::Trait(inputs, _) => Some((None, inputs.map_bound(|ty| ty.tuple_fields()[i]))),
|
|
}
|
|
}
|
|
|
|
/// Gets the result type, if one could be found. Note that the result type of a trait may not be
|
|
/// specified.
|
|
pub fn output(self) -> Option<Binder<'tcx, Ty<'tcx>>> {
|
|
match self {
|
|
Self::Sig(sig) | Self::Closure(_, sig) => Some(sig.output()),
|
|
Self::Trait(_, output) => output,
|
|
}
|
|
}
|
|
}
|
|
|
|
/// If the expression is function like, get the signature for it.
|
|
pub fn expr_sig<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'_>) -> Option<ExprFnSig<'tcx>> {
|
|
if let Res::Def(DefKind::Fn | DefKind::Ctor(_, CtorKind::Fn) | DefKind::AssocFn, id) = path_res(cx, expr) {
|
|
Some(ExprFnSig::Sig(cx.tcx.fn_sig(id)))
|
|
} else {
|
|
ty_sig(cx, cx.typeck_results().expr_ty_adjusted(expr).peel_refs())
|
|
}
|
|
}
|
|
|
|
fn ty_sig<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> Option<ExprFnSig<'tcx>> {
|
|
match *ty.kind() {
|
|
ty::Closure(id, subs) => {
|
|
let decl = id
|
|
.as_local()
|
|
.and_then(|id| cx.tcx.hir().fn_decl_by_hir_id(cx.tcx.hir().local_def_id_to_hir_id(id)));
|
|
Some(ExprFnSig::Closure(decl, subs.as_closure().sig()))
|
|
},
|
|
ty::FnDef(id, subs) => Some(ExprFnSig::Sig(cx.tcx.bound_fn_sig(id).subst(cx.tcx, subs))),
|
|
ty::FnPtr(sig) => Some(ExprFnSig::Sig(sig)),
|
|
ty::Dynamic(bounds, _) => {
|
|
let lang_items = cx.tcx.lang_items();
|
|
match bounds.principal() {
|
|
Some(bound)
|
|
if Some(bound.def_id()) == lang_items.fn_trait()
|
|
|| Some(bound.def_id()) == lang_items.fn_once_trait()
|
|
|| Some(bound.def_id()) == lang_items.fn_mut_trait() =>
|
|
{
|
|
let output = bounds
|
|
.projection_bounds()
|
|
.find(|p| lang_items.fn_once_output().map_or(false, |id| id == p.item_def_id()))
|
|
.map(|p| p.map_bound(|p| p.term.ty().unwrap()));
|
|
Some(ExprFnSig::Trait(bound.map_bound(|b| b.substs.type_at(0)), output))
|
|
},
|
|
_ => None,
|
|
}
|
|
},
|
|
ty::Projection(proj) => match cx.tcx.try_normalize_erasing_regions(cx.param_env, ty) {
|
|
Ok(normalized_ty) if normalized_ty != ty => ty_sig(cx, normalized_ty),
|
|
_ => sig_for_projection(cx, proj).or_else(|| sig_from_bounds(cx, ty)),
|
|
},
|
|
ty::Param(_) => sig_from_bounds(cx, ty),
|
|
_ => None,
|
|
}
|
|
}
|
|
|
|
fn sig_from_bounds<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> Option<ExprFnSig<'tcx>> {
|
|
let mut inputs = None;
|
|
let mut output = None;
|
|
let lang_items = cx.tcx.lang_items();
|
|
|
|
for (pred, _) in all_predicates_of(cx.tcx, cx.typeck_results().hir_owner.to_def_id()) {
|
|
match pred.kind().skip_binder() {
|
|
PredicateKind::Trait(p)
|
|
if (lang_items.fn_trait() == Some(p.def_id())
|
|
|| lang_items.fn_mut_trait() == Some(p.def_id())
|
|
|| lang_items.fn_once_trait() == Some(p.def_id()))
|
|
&& p.self_ty() == ty =>
|
|
{
|
|
if inputs.is_some() {
|
|
// Multiple different fn trait impls. Is this even allowed?
|
|
return None;
|
|
}
|
|
inputs = Some(pred.kind().rebind(p.trait_ref.substs.type_at(1)));
|
|
},
|
|
PredicateKind::Projection(p)
|
|
if Some(p.projection_ty.item_def_id) == lang_items.fn_once_output()
|
|
&& p.projection_ty.self_ty() == ty =>
|
|
{
|
|
if output.is_some() {
|
|
// Multiple different fn trait impls. Is this even allowed?
|
|
return None;
|
|
}
|
|
output = Some(pred.kind().rebind(p.term.ty().unwrap()));
|
|
},
|
|
_ => (),
|
|
}
|
|
}
|
|
|
|
inputs.map(|ty| ExprFnSig::Trait(ty, output))
|
|
}
|
|
|
|
fn sig_for_projection<'tcx>(cx: &LateContext<'tcx>, ty: ProjectionTy<'tcx>) -> Option<ExprFnSig<'tcx>> {
|
|
let mut inputs = None;
|
|
let mut output = None;
|
|
let lang_items = cx.tcx.lang_items();
|
|
|
|
for pred in cx
|
|
.tcx
|
|
.bound_explicit_item_bounds(ty.item_def_id)
|
|
.transpose_iter()
|
|
.map(|x| x.map_bound(|(p, _)| p))
|
|
{
|
|
match pred.0.kind().skip_binder() {
|
|
PredicateKind::Trait(p)
|
|
if (lang_items.fn_trait() == Some(p.def_id())
|
|
|| lang_items.fn_mut_trait() == Some(p.def_id())
|
|
|| lang_items.fn_once_trait() == Some(p.def_id())) =>
|
|
{
|
|
if inputs.is_some() {
|
|
// Multiple different fn trait impls. Is this even allowed?
|
|
return None;
|
|
}
|
|
inputs = Some(
|
|
pred.map_bound(|pred| pred.kind().rebind(p.trait_ref.substs.type_at(1)))
|
|
.subst(cx.tcx, ty.substs),
|
|
);
|
|
},
|
|
PredicateKind::Projection(p) if Some(p.projection_ty.item_def_id) == lang_items.fn_once_output() => {
|
|
if output.is_some() {
|
|
// Multiple different fn trait impls. Is this even allowed?
|
|
return None;
|
|
}
|
|
output = Some(
|
|
pred.map_bound(|pred| pred.kind().rebind(p.term.ty().unwrap()))
|
|
.subst(cx.tcx, ty.substs),
|
|
);
|
|
},
|
|
_ => (),
|
|
}
|
|
}
|
|
|
|
inputs.map(|ty| ExprFnSig::Trait(ty, output))
|
|
}
|
|
|
|
#[derive(Clone, Copy)]
|
|
pub enum EnumValue {
|
|
Unsigned(u128),
|
|
Signed(i128),
|
|
}
|
|
impl core::ops::Add<u32> for EnumValue {
|
|
type Output = Self;
|
|
fn add(self, n: u32) -> Self::Output {
|
|
match self {
|
|
Self::Unsigned(x) => Self::Unsigned(x + u128::from(n)),
|
|
Self::Signed(x) => Self::Signed(x + i128::from(n)),
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Attempts to read the given constant as though it were an an enum value.
|
|
#[expect(clippy::cast_possible_truncation, clippy::cast_possible_wrap)]
|
|
pub fn read_explicit_enum_value(tcx: TyCtxt<'_>, id: DefId) -> Option<EnumValue> {
|
|
if let Ok(ConstValue::Scalar(Scalar::Int(value))) = tcx.const_eval_poly(id) {
|
|
match tcx.type_of(id).kind() {
|
|
ty::Int(_) => Some(EnumValue::Signed(match value.size().bytes() {
|
|
1 => i128::from(value.assert_bits(Size::from_bytes(1)) as u8 as i8),
|
|
2 => i128::from(value.assert_bits(Size::from_bytes(2)) as u16 as i16),
|
|
4 => i128::from(value.assert_bits(Size::from_bytes(4)) as u32 as i32),
|
|
8 => i128::from(value.assert_bits(Size::from_bytes(8)) as u64 as i64),
|
|
16 => value.assert_bits(Size::from_bytes(16)) as i128,
|
|
_ => return None,
|
|
})),
|
|
ty::Uint(_) => Some(EnumValue::Unsigned(match value.size().bytes() {
|
|
1 => value.assert_bits(Size::from_bytes(1)),
|
|
2 => value.assert_bits(Size::from_bytes(2)),
|
|
4 => value.assert_bits(Size::from_bytes(4)),
|
|
8 => value.assert_bits(Size::from_bytes(8)),
|
|
16 => value.assert_bits(Size::from_bytes(16)),
|
|
_ => return None,
|
|
})),
|
|
_ => None,
|
|
}
|
|
} else {
|
|
None
|
|
}
|
|
}
|
|
|
|
/// Gets the value of the given variant.
|
|
pub fn get_discriminant_value(tcx: TyCtxt<'_>, adt: AdtDef<'_>, i: VariantIdx) -> EnumValue {
|
|
let variant = &adt.variant(i);
|
|
match variant.discr {
|
|
VariantDiscr::Explicit(id) => read_explicit_enum_value(tcx, id).unwrap(),
|
|
VariantDiscr::Relative(x) => match adt.variant((i.as_usize() - x as usize).into()).discr {
|
|
VariantDiscr::Explicit(id) => read_explicit_enum_value(tcx, id).unwrap() + x,
|
|
VariantDiscr::Relative(_) => EnumValue::Unsigned(x.into()),
|
|
},
|
|
}
|
|
}
|
|
|
|
/// Check if the given type is either `core::ffi::c_void`, `std::os::raw::c_void`, or one of the
|
|
/// platform specific `libc::<platform>::c_void` types in libc.
|
|
pub fn is_c_void(cx: &LateContext<'_>, ty: Ty<'_>) -> bool {
|
|
if let ty::Adt(adt, _) = ty.kind()
|
|
&& let &[krate, .., name] = &*cx.get_def_path(adt.did())
|
|
&& let sym::libc | sym::core | sym::std = krate
|
|
&& name.as_str() == "c_void"
|
|
{
|
|
true
|
|
} else {
|
|
false
|
|
}
|
|
}
|
|
|
|
pub fn for_each_top_level_late_bound_region<B>(
|
|
ty: Ty<'_>,
|
|
f: impl FnMut(BoundRegion) -> ControlFlow<B>,
|
|
) -> ControlFlow<B> {
|
|
struct V<F> {
|
|
index: u32,
|
|
f: F,
|
|
}
|
|
impl<'tcx, B, F: FnMut(BoundRegion) -> ControlFlow<B>> TypeVisitor<'tcx> for V<F> {
|
|
type BreakTy = B;
|
|
fn visit_region(&mut self, r: Region<'tcx>) -> ControlFlow<Self::BreakTy> {
|
|
if let RegionKind::ReLateBound(idx, bound) = r.kind() && idx.as_u32() == self.index {
|
|
(self.f)(bound)
|
|
} else {
|
|
ControlFlow::Continue(())
|
|
}
|
|
}
|
|
fn visit_binder<T: TypeFoldable<'tcx>>(&mut self, t: &Binder<'tcx, T>) -> ControlFlow<Self::BreakTy> {
|
|
self.index += 1;
|
|
let res = t.super_visit_with(self);
|
|
self.index -= 1;
|
|
res
|
|
}
|
|
}
|
|
ty.visit_with(&mut V { index: 0, f })
|
|
}
|
|
|
|
/// Gets the struct or enum variant from the given `Res`
|
|
pub fn variant_of_res<'tcx>(cx: &LateContext<'tcx>, res: Res) -> Option<&'tcx VariantDef> {
|
|
match res {
|
|
Res::Def(DefKind::Struct, id) => Some(cx.tcx.adt_def(id).non_enum_variant()),
|
|
Res::Def(DefKind::Variant, id) => Some(cx.tcx.adt_def(cx.tcx.parent(id)).variant_with_id(id)),
|
|
Res::Def(DefKind::Ctor(CtorOf::Struct, _), id) => Some(cx.tcx.adt_def(cx.tcx.parent(id)).non_enum_variant()),
|
|
Res::Def(DefKind::Ctor(CtorOf::Variant, _), id) => {
|
|
let var_id = cx.tcx.parent(id);
|
|
Some(cx.tcx.adt_def(cx.tcx.parent(var_id)).variant_with_id(var_id))
|
|
},
|
|
Res::SelfCtor(id) => Some(cx.tcx.type_of(id).ty_adt_def().unwrap().non_enum_variant()),
|
|
_ => None,
|
|
}
|
|
}
|