1482 lines
54 KiB
Rust
1482 lines
54 KiB
Rust
//! "Collection" is the process of determining the type and other external
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//! details of each item in Rust. Collection is specifically concerned
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//! with *inter-procedural* things -- for example, for a function
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//! definition, collection will figure out the type and signature of the
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//! function, but it will not visit the *body* of the function in any way,
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//! nor examine type annotations on local variables (that's the job of
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//! type *checking*).
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//!
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//! Collecting is ultimately defined by a bundle of queries that
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//! inquire after various facts about the items in the crate (e.g.,
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//! `type_of`, `generics_of`, `predicates_of`, etc). See the `provide` function
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//! for the full set.
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//!
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//! At present, however, we do run collection across all items in the
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//! crate as a kind of pass. This should eventually be factored away.
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use crate::astconv::AstConv;
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use crate::check::intrinsic::intrinsic_operation_unsafety;
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use crate::errors;
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use hir::def::DefKind;
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use rustc_data_structures::captures::Captures;
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use rustc_data_structures::fx::{FxHashMap, FxHashSet};
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use rustc_errors::{Applicability, DiagnosticBuilder, ErrorGuaranteed, StashKey};
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use rustc_hir as hir;
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use rustc_hir::def_id::{DefId, LocalDefId};
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use rustc_hir::intravisit::{self, Visitor};
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use rustc_hir::{GenericParamKind, Node};
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use rustc_infer::infer::{InferCtxt, TyCtxtInferExt};
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use rustc_infer::traits::ObligationCause;
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use rustc_middle::hir::nested_filter;
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use rustc_middle::ty::query::Providers;
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use rustc_middle::ty::util::{Discr, IntTypeExt};
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use rustc_middle::ty::{self, AdtKind, Const, IsSuggestable, ToPredicate, Ty, TyCtxt};
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use rustc_span::symbol::{kw, sym, Ident, Symbol};
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use rustc_span::Span;
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use rustc_target::spec::abi;
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use rustc_trait_selection::infer::InferCtxtExt;
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use rustc_trait_selection::traits::error_reporting::suggestions::NextTypeParamName;
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use rustc_trait_selection::traits::ObligationCtxt;
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use std::iter;
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mod generics_of;
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mod item_bounds;
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mod predicates_of;
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mod resolve_bound_vars;
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mod type_of;
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///////////////////////////////////////////////////////////////////////////
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// Main entry point
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fn collect_mod_item_types(tcx: TyCtxt<'_>, module_def_id: LocalDefId) {
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tcx.hir().visit_item_likes_in_module(module_def_id, &mut CollectItemTypesVisitor { tcx });
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}
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pub fn provide(providers: &mut Providers) {
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resolve_bound_vars::provide(providers);
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*providers = Providers {
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opt_const_param_of: type_of::opt_const_param_of,
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type_of: type_of::type_of,
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item_bounds: item_bounds::item_bounds,
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explicit_item_bounds: item_bounds::explicit_item_bounds,
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generics_of: generics_of::generics_of,
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predicates_of: predicates_of::predicates_of,
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predicates_defined_on,
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explicit_predicates_of: predicates_of::explicit_predicates_of,
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super_predicates_of: predicates_of::super_predicates_of,
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super_predicates_that_define_assoc_type:
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predicates_of::super_predicates_that_define_assoc_type,
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trait_explicit_predicates_and_bounds: predicates_of::trait_explicit_predicates_and_bounds,
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type_param_predicates: predicates_of::type_param_predicates,
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trait_def,
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adt_def,
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fn_sig,
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impl_trait_ref,
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impl_polarity,
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is_foreign_item,
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generator_kind,
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collect_mod_item_types,
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is_type_alias_impl_trait,
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..*providers
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};
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}
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///////////////////////////////////////////////////////////////////////////
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/// Context specific to some particular item. This is what implements
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/// [`AstConv`].
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///
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/// # `ItemCtxt` vs `FnCtxt`
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///
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/// `ItemCtxt` is primarily used to type-check item signatures and lower them
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/// from HIR to their [`ty::Ty`] representation, which is exposed using [`AstConv`].
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/// It's also used for the bodies of items like structs where the body (the fields)
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/// are just signatures.
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///
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/// This is in contrast to `FnCtxt`, which is used to type-check bodies of
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/// functions, closures, and `const`s -- anywhere that expressions and statements show up.
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///
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/// An important thing to note is that `ItemCtxt` does no inference -- it has no [`InferCtxt`] --
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/// while `FnCtxt` does do inference.
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///
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/// [`InferCtxt`]: rustc_infer::infer::InferCtxt
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///
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/// # Trait predicates
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///
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/// `ItemCtxt` has information about the predicates that are defined
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/// on the trait. Unfortunately, this predicate information is
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/// available in various different forms at various points in the
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/// process. So we can't just store a pointer to e.g., the AST or the
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/// parsed ty form, we have to be more flexible. To this end, the
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/// `ItemCtxt` is parameterized by a `DefId` that it uses to satisfy
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/// `get_type_parameter_bounds` requests, drawing the information from
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/// the AST (`hir::Generics`), recursively.
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pub struct ItemCtxt<'tcx> {
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tcx: TyCtxt<'tcx>,
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item_def_id: LocalDefId,
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}
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///////////////////////////////////////////////////////////////////////////
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#[derive(Default)]
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pub(crate) struct HirPlaceholderCollector(pub(crate) Vec<Span>);
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impl<'v> Visitor<'v> for HirPlaceholderCollector {
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fn visit_ty(&mut self, t: &'v hir::Ty<'v>) {
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if let hir::TyKind::Infer = t.kind {
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self.0.push(t.span);
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}
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intravisit::walk_ty(self, t)
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}
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fn visit_generic_arg(&mut self, generic_arg: &'v hir::GenericArg<'v>) {
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match generic_arg {
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hir::GenericArg::Infer(inf) => {
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self.0.push(inf.span);
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intravisit::walk_inf(self, inf);
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}
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hir::GenericArg::Type(t) => self.visit_ty(t),
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_ => {}
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}
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}
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fn visit_array_length(&mut self, length: &'v hir::ArrayLen) {
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if let &hir::ArrayLen::Infer(_, span) = length {
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self.0.push(span);
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}
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intravisit::walk_array_len(self, length)
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}
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}
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struct CollectItemTypesVisitor<'tcx> {
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tcx: TyCtxt<'tcx>,
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}
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/// If there are any placeholder types (`_`), emit an error explaining that this is not allowed
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/// and suggest adding type parameters in the appropriate place, taking into consideration any and
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/// all already existing generic type parameters to avoid suggesting a name that is already in use.
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pub(crate) fn placeholder_type_error<'tcx>(
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tcx: TyCtxt<'tcx>,
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generics: Option<&hir::Generics<'_>>,
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placeholder_types: Vec<Span>,
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suggest: bool,
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hir_ty: Option<&hir::Ty<'_>>,
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kind: &'static str,
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) {
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if placeholder_types.is_empty() {
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return;
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}
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placeholder_type_error_diag(tcx, generics, placeholder_types, vec![], suggest, hir_ty, kind)
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.emit();
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}
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pub(crate) fn placeholder_type_error_diag<'tcx>(
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tcx: TyCtxt<'tcx>,
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generics: Option<&hir::Generics<'_>>,
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placeholder_types: Vec<Span>,
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additional_spans: Vec<Span>,
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suggest: bool,
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hir_ty: Option<&hir::Ty<'_>>,
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kind: &'static str,
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) -> DiagnosticBuilder<'tcx, ErrorGuaranteed> {
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if placeholder_types.is_empty() {
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return bad_placeholder(tcx, additional_spans, kind);
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}
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let params = generics.map(|g| g.params).unwrap_or_default();
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let type_name = params.next_type_param_name(None);
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let mut sugg: Vec<_> =
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placeholder_types.iter().map(|sp| (*sp, (*type_name).to_string())).collect();
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if let Some(generics) = generics {
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if let Some(arg) = params.iter().find(|arg| {
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matches!(arg.name, hir::ParamName::Plain(Ident { name: kw::Underscore, .. }))
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}) {
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// Account for `_` already present in cases like `struct S<_>(_);` and suggest
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// `struct S<T>(T);` instead of `struct S<_, T>(T);`.
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sugg.push((arg.span, (*type_name).to_string()));
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} else if let Some(span) = generics.span_for_param_suggestion() {
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// Account for bounds, we want `fn foo<T: E, K>(_: K)` not `fn foo<T, K: E>(_: K)`.
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sugg.push((span, format!(", {}", type_name)));
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} else {
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sugg.push((generics.span, format!("<{}>", type_name)));
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}
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}
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let mut err =
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bad_placeholder(tcx, placeholder_types.into_iter().chain(additional_spans).collect(), kind);
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// Suggest, but only if it is not a function in const or static
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if suggest {
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let mut is_fn = false;
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let mut is_const_or_static = false;
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if let Some(hir_ty) = hir_ty && let hir::TyKind::BareFn(_) = hir_ty.kind {
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is_fn = true;
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// Check if parent is const or static
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let parent_id = tcx.hir().parent_id(hir_ty.hir_id);
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let parent_node = tcx.hir().get(parent_id);
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is_const_or_static = matches!(
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parent_node,
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Node::Item(&hir::Item {
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kind: hir::ItemKind::Const(..) | hir::ItemKind::Static(..),
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..
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}) | Node::TraitItem(&hir::TraitItem {
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kind: hir::TraitItemKind::Const(..),
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..
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}) | Node::ImplItem(&hir::ImplItem { kind: hir::ImplItemKind::Const(..), .. })
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);
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}
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// if function is wrapped around a const or static,
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// then don't show the suggestion
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if !(is_fn && is_const_or_static) {
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err.multipart_suggestion(
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"use type parameters instead",
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sugg,
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Applicability::HasPlaceholders,
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);
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}
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}
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err
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}
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fn reject_placeholder_type_signatures_in_item<'tcx>(
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tcx: TyCtxt<'tcx>,
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item: &'tcx hir::Item<'tcx>,
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) {
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let (generics, suggest) = match &item.kind {
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hir::ItemKind::Union(_, generics)
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| hir::ItemKind::Enum(_, generics)
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| hir::ItemKind::TraitAlias(generics, _)
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| hir::ItemKind::Trait(_, _, generics, ..)
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| hir::ItemKind::Impl(hir::Impl { generics, .. })
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| hir::ItemKind::Struct(_, generics) => (generics, true),
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hir::ItemKind::OpaqueTy(hir::OpaqueTy { generics, .. })
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| hir::ItemKind::TyAlias(_, generics) => (generics, false),
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// `static`, `fn` and `const` are handled elsewhere to suggest appropriate type.
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_ => return,
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};
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let mut visitor = HirPlaceholderCollector::default();
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visitor.visit_item(item);
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placeholder_type_error(tcx, Some(generics), visitor.0, suggest, None, item.kind.descr());
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}
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impl<'tcx> Visitor<'tcx> for CollectItemTypesVisitor<'tcx> {
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type NestedFilter = nested_filter::OnlyBodies;
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fn nested_visit_map(&mut self) -> Self::Map {
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self.tcx.hir()
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}
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fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
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convert_item(self.tcx, item.item_id());
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reject_placeholder_type_signatures_in_item(self.tcx, item);
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intravisit::walk_item(self, item);
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}
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fn visit_generics(&mut self, generics: &'tcx hir::Generics<'tcx>) {
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for param in generics.params {
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match param.kind {
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hir::GenericParamKind::Lifetime { .. } => {}
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hir::GenericParamKind::Type { default: Some(_), .. } => {
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self.tcx.ensure().type_of(param.def_id);
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}
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hir::GenericParamKind::Type { .. } => {}
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hir::GenericParamKind::Const { default, .. } => {
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self.tcx.ensure().type_of(param.def_id);
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if let Some(default) = default {
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// need to store default and type of default
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self.tcx.ensure().type_of(default.def_id);
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self.tcx.ensure().const_param_default(param.def_id);
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}
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}
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}
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}
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intravisit::walk_generics(self, generics);
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}
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fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) {
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if let hir::ExprKind::Closure(closure) = expr.kind {
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self.tcx.ensure().generics_of(closure.def_id);
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self.tcx.ensure().codegen_fn_attrs(closure.def_id);
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// We do not call `type_of` for closures here as that
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// depends on typecheck and would therefore hide
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// any further errors in case one typeck fails.
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}
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intravisit::walk_expr(self, expr);
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}
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fn visit_trait_item(&mut self, trait_item: &'tcx hir::TraitItem<'tcx>) {
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convert_trait_item(self.tcx, trait_item.trait_item_id());
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intravisit::walk_trait_item(self, trait_item);
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}
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fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem<'tcx>) {
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convert_impl_item(self.tcx, impl_item.impl_item_id());
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intravisit::walk_impl_item(self, impl_item);
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}
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}
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///////////////////////////////////////////////////////////////////////////
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// Utility types and common code for the above passes.
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fn bad_placeholder<'tcx>(
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tcx: TyCtxt<'tcx>,
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mut spans: Vec<Span>,
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kind: &'static str,
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) -> DiagnosticBuilder<'tcx, ErrorGuaranteed> {
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let kind = if kind.ends_with('s') { format!("{}es", kind) } else { format!("{}s", kind) };
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spans.sort();
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tcx.sess.create_err(errors::PlaceholderNotAllowedItemSignatures { spans, kind })
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}
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impl<'tcx> ItemCtxt<'tcx> {
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pub fn new(tcx: TyCtxt<'tcx>, item_def_id: LocalDefId) -> ItemCtxt<'tcx> {
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ItemCtxt { tcx, item_def_id }
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}
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pub fn to_ty(&self, ast_ty: &hir::Ty<'_>) -> Ty<'tcx> {
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self.astconv().ast_ty_to_ty(ast_ty)
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}
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pub fn hir_id(&self) -> hir::HirId {
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self.tcx.hir().local_def_id_to_hir_id(self.item_def_id)
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}
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pub fn node(&self) -> hir::Node<'tcx> {
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self.tcx.hir().get(self.hir_id())
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}
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}
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impl<'tcx> AstConv<'tcx> for ItemCtxt<'tcx> {
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fn tcx(&self) -> TyCtxt<'tcx> {
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self.tcx
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}
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fn item_def_id(&self) -> DefId {
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self.item_def_id.to_def_id()
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}
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fn get_type_parameter_bounds(
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&self,
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span: Span,
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def_id: LocalDefId,
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|
assoc_name: Ident,
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) -> ty::GenericPredicates<'tcx> {
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self.tcx.at(span).type_param_predicates((self.item_def_id, def_id, assoc_name))
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}
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|
|
|
fn re_infer(&self, _: Option<&ty::GenericParamDef>, _: Span) -> Option<ty::Region<'tcx>> {
|
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None
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|
}
|
|
|
|
fn allow_ty_infer(&self) -> bool {
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false
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}
|
|
|
|
fn ty_infer(&self, _: Option<&ty::GenericParamDef>, span: Span) -> Ty<'tcx> {
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self.tcx().ty_error_with_message(span, "bad placeholder type")
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}
|
|
|
|
fn ct_infer(&self, ty: Ty<'tcx>, _: Option<&ty::GenericParamDef>, span: Span) -> Const<'tcx> {
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|
let ty = self.tcx.fold_regions(ty, |r, _| match *r {
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|
ty::ReErased => self.tcx.lifetimes.re_static,
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_ => r,
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});
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self.tcx().const_error_with_message(ty, span, "bad placeholder constant")
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|
}
|
|
|
|
fn projected_ty_from_poly_trait_ref(
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|
&self,
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|
span: Span,
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|
item_def_id: DefId,
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|
item_segment: &hir::PathSegment<'_>,
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|
poly_trait_ref: ty::PolyTraitRef<'tcx>,
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|
) -> Ty<'tcx> {
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|
if let Some(trait_ref) = poly_trait_ref.no_bound_vars() {
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|
let item_substs = self.astconv().create_substs_for_associated_item(
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|
span,
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|
item_def_id,
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|
item_segment,
|
|
trait_ref.substs,
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|
);
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|
self.tcx().mk_projection(item_def_id, item_substs)
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|
} else {
|
|
// There are no late-bound regions; we can just ignore the binder.
|
|
let (mut mpart_sugg, mut inferred_sugg) = (None, None);
|
|
let mut bound = String::new();
|
|
|
|
match self.node() {
|
|
hir::Node::Field(_) | hir::Node::Ctor(_) | hir::Node::Variant(_) => {
|
|
let item = self
|
|
.tcx
|
|
.hir()
|
|
.expect_item(self.tcx.hir().get_parent_item(self.hir_id()).def_id);
|
|
match &item.kind {
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|
hir::ItemKind::Enum(_, generics)
|
|
| hir::ItemKind::Struct(_, generics)
|
|
| hir::ItemKind::Union(_, generics) => {
|
|
let lt_name = get_new_lifetime_name(self.tcx, poly_trait_ref, generics);
|
|
let (lt_sp, sugg) = match generics.params {
|
|
[] => (generics.span, format!("<{}>", lt_name)),
|
|
[bound, ..] => {
|
|
(bound.span.shrink_to_lo(), format!("{}, ", lt_name))
|
|
}
|
|
};
|
|
mpart_sugg = Some(errors::AssociatedTypeTraitUninferredGenericParamsMultipartSuggestion {
|
|
fspan: lt_sp,
|
|
first: sugg,
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|
sspan: span.with_hi(item_segment.ident.span.lo()),
|
|
second: format!(
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|
"{}::",
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|
// Replace the existing lifetimes with a new named lifetime.
|
|
self.tcx.replace_late_bound_regions_uncached(
|
|
poly_trait_ref,
|
|
|_| {
|
|
self.tcx.mk_re_early_bound(ty::EarlyBoundRegion {
|
|
def_id: item_def_id,
|
|
index: 0,
|
|
name: Symbol::intern(<_name),
|
|
})
|
|
}
|
|
),
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|
),
|
|
});
|
|
}
|
|
_ => {}
|
|
}
|
|
}
|
|
hir::Node::Item(hir::Item {
|
|
kind:
|
|
hir::ItemKind::Struct(..) | hir::ItemKind::Enum(..) | hir::ItemKind::Union(..),
|
|
..
|
|
}) => {}
|
|
hir::Node::Item(_)
|
|
| hir::Node::ForeignItem(_)
|
|
| hir::Node::TraitItem(_)
|
|
| hir::Node::ImplItem(_) => {
|
|
inferred_sugg = Some(span.with_hi(item_segment.ident.span.lo()));
|
|
bound = format!(
|
|
"{}::",
|
|
// Erase named lt, we want `<A as B<'_>::C`, not `<A as B<'a>::C`.
|
|
self.tcx.anonymize_bound_vars(poly_trait_ref).skip_binder(),
|
|
);
|
|
}
|
|
_ => {}
|
|
}
|
|
self.tcx().ty_error(self.tcx().sess.emit_err(
|
|
errors::AssociatedTypeTraitUninferredGenericParams {
|
|
span,
|
|
inferred_sugg,
|
|
bound,
|
|
mpart_sugg,
|
|
},
|
|
))
|
|
}
|
|
}
|
|
|
|
fn probe_adt(&self, _span: Span, ty: Ty<'tcx>) -> Option<ty::AdtDef<'tcx>> {
|
|
// FIXME(#103640): Should we handle the case where `ty` is a projection?
|
|
ty.ty_adt_def()
|
|
}
|
|
|
|
fn set_tainted_by_errors(&self, _: ErrorGuaranteed) {
|
|
// There's no obvious place to track this, so just let it go.
|
|
}
|
|
|
|
fn record_ty(&self, _hir_id: hir::HirId, _ty: Ty<'tcx>, _span: Span) {
|
|
// There's no place to record types from signatures?
|
|
}
|
|
|
|
fn infcx(&self) -> Option<&InferCtxt<'tcx>> {
|
|
None
|
|
}
|
|
}
|
|
|
|
/// Synthesize a new lifetime name that doesn't clash with any of the lifetimes already present.
|
|
fn get_new_lifetime_name<'tcx>(
|
|
tcx: TyCtxt<'tcx>,
|
|
poly_trait_ref: ty::PolyTraitRef<'tcx>,
|
|
generics: &hir::Generics<'tcx>,
|
|
) -> String {
|
|
let existing_lifetimes = tcx
|
|
.collect_referenced_late_bound_regions(&poly_trait_ref)
|
|
.into_iter()
|
|
.filter_map(|lt| {
|
|
if let ty::BoundRegionKind::BrNamed(_, name) = lt {
|
|
Some(name.as_str().to_string())
|
|
} else {
|
|
None
|
|
}
|
|
})
|
|
.chain(generics.params.iter().filter_map(|param| {
|
|
if let hir::GenericParamKind::Lifetime { .. } = ¶m.kind {
|
|
Some(param.name.ident().as_str().to_string())
|
|
} else {
|
|
None
|
|
}
|
|
}))
|
|
.collect::<FxHashSet<String>>();
|
|
|
|
let a_to_z_repeat_n = |n| {
|
|
(b'a'..=b'z').map(move |c| {
|
|
let mut s = '\''.to_string();
|
|
s.extend(std::iter::repeat(char::from(c)).take(n));
|
|
s
|
|
})
|
|
};
|
|
|
|
// If all single char lifetime names are present, we wrap around and double the chars.
|
|
(1..).flat_map(a_to_z_repeat_n).find(|lt| !existing_lifetimes.contains(lt.as_str())).unwrap()
|
|
}
|
|
|
|
fn convert_item(tcx: TyCtxt<'_>, item_id: hir::ItemId) {
|
|
let it = tcx.hir().item(item_id);
|
|
debug!("convert: item {} with id {}", it.ident, it.hir_id());
|
|
let def_id = item_id.owner_id.def_id;
|
|
|
|
match &it.kind {
|
|
// These don't define types.
|
|
hir::ItemKind::ExternCrate(_)
|
|
| hir::ItemKind::Use(..)
|
|
| hir::ItemKind::Macro(..)
|
|
| hir::ItemKind::Mod(_)
|
|
| hir::ItemKind::GlobalAsm(_) => {}
|
|
hir::ItemKind::ForeignMod { items, .. } => {
|
|
for item in *items {
|
|
let item = tcx.hir().foreign_item(item.id);
|
|
tcx.ensure().generics_of(item.owner_id);
|
|
tcx.ensure().type_of(item.owner_id);
|
|
tcx.ensure().predicates_of(item.owner_id);
|
|
match item.kind {
|
|
hir::ForeignItemKind::Fn(..) => {
|
|
tcx.ensure().codegen_fn_attrs(item.owner_id);
|
|
tcx.ensure().fn_sig(item.owner_id)
|
|
}
|
|
hir::ForeignItemKind::Static(..) => {
|
|
tcx.ensure().codegen_fn_attrs(item.owner_id);
|
|
let mut visitor = HirPlaceholderCollector::default();
|
|
visitor.visit_foreign_item(item);
|
|
placeholder_type_error(
|
|
tcx,
|
|
None,
|
|
visitor.0,
|
|
false,
|
|
None,
|
|
"static variable",
|
|
);
|
|
}
|
|
_ => (),
|
|
}
|
|
}
|
|
}
|
|
hir::ItemKind::Enum(..) => {
|
|
tcx.ensure().generics_of(def_id);
|
|
tcx.ensure().type_of(def_id);
|
|
tcx.ensure().predicates_of(def_id);
|
|
convert_enum_variant_types(tcx, def_id.to_def_id());
|
|
}
|
|
hir::ItemKind::Impl { .. } => {
|
|
tcx.ensure().generics_of(def_id);
|
|
tcx.ensure().type_of(def_id);
|
|
tcx.ensure().impl_trait_ref(def_id);
|
|
tcx.ensure().predicates_of(def_id);
|
|
}
|
|
hir::ItemKind::Trait(..) => {
|
|
tcx.ensure().generics_of(def_id);
|
|
tcx.ensure().trait_def(def_id);
|
|
tcx.at(it.span).super_predicates_of(def_id);
|
|
tcx.ensure().predicates_of(def_id);
|
|
}
|
|
hir::ItemKind::TraitAlias(..) => {
|
|
tcx.ensure().generics_of(def_id);
|
|
tcx.at(it.span).super_predicates_of(def_id);
|
|
tcx.ensure().predicates_of(def_id);
|
|
}
|
|
hir::ItemKind::Struct(struct_def, _) | hir::ItemKind::Union(struct_def, _) => {
|
|
tcx.ensure().generics_of(def_id);
|
|
tcx.ensure().type_of(def_id);
|
|
tcx.ensure().predicates_of(def_id);
|
|
|
|
for f in struct_def.fields() {
|
|
tcx.ensure().generics_of(f.def_id);
|
|
tcx.ensure().type_of(f.def_id);
|
|
tcx.ensure().predicates_of(f.def_id);
|
|
}
|
|
|
|
if let Some(ctor_def_id) = struct_def.ctor_def_id() {
|
|
convert_variant_ctor(tcx, ctor_def_id);
|
|
}
|
|
}
|
|
|
|
// Don't call `type_of` on opaque types, since that depends on type
|
|
// checking function bodies. `check_item_type` ensures that it's called
|
|
// instead.
|
|
hir::ItemKind::OpaqueTy(..) => {
|
|
tcx.ensure().generics_of(def_id);
|
|
tcx.ensure().predicates_of(def_id);
|
|
tcx.ensure().explicit_item_bounds(def_id);
|
|
tcx.ensure().item_bounds(def_id);
|
|
}
|
|
|
|
hir::ItemKind::TyAlias(..) => {
|
|
tcx.ensure().generics_of(def_id);
|
|
tcx.ensure().type_of(def_id);
|
|
tcx.ensure().predicates_of(def_id);
|
|
}
|
|
|
|
hir::ItemKind::Static(ty, ..) | hir::ItemKind::Const(ty, ..) => {
|
|
tcx.ensure().generics_of(def_id);
|
|
tcx.ensure().type_of(def_id);
|
|
tcx.ensure().predicates_of(def_id);
|
|
if !is_suggestable_infer_ty(ty) {
|
|
let mut visitor = HirPlaceholderCollector::default();
|
|
visitor.visit_item(it);
|
|
placeholder_type_error(tcx, None, visitor.0, false, None, it.kind.descr());
|
|
}
|
|
}
|
|
|
|
hir::ItemKind::Fn(..) => {
|
|
tcx.ensure().generics_of(def_id);
|
|
tcx.ensure().type_of(def_id);
|
|
tcx.ensure().predicates_of(def_id);
|
|
tcx.ensure().fn_sig(def_id);
|
|
tcx.ensure().codegen_fn_attrs(def_id);
|
|
}
|
|
}
|
|
}
|
|
|
|
fn convert_trait_item(tcx: TyCtxt<'_>, trait_item_id: hir::TraitItemId) {
|
|
let trait_item = tcx.hir().trait_item(trait_item_id);
|
|
let def_id = trait_item_id.owner_id;
|
|
tcx.ensure().generics_of(def_id);
|
|
|
|
match trait_item.kind {
|
|
hir::TraitItemKind::Fn(..) => {
|
|
tcx.ensure().codegen_fn_attrs(def_id);
|
|
tcx.ensure().type_of(def_id);
|
|
tcx.ensure().fn_sig(def_id);
|
|
}
|
|
|
|
hir::TraitItemKind::Const(.., Some(_)) => {
|
|
tcx.ensure().type_of(def_id);
|
|
}
|
|
|
|
hir::TraitItemKind::Const(hir_ty, _) => {
|
|
tcx.ensure().type_of(def_id);
|
|
// Account for `const C: _;`.
|
|
let mut visitor = HirPlaceholderCollector::default();
|
|
visitor.visit_trait_item(trait_item);
|
|
if !tcx.sess.diagnostic().has_stashed_diagnostic(hir_ty.span, StashKey::ItemNoType) {
|
|
placeholder_type_error(tcx, None, visitor.0, false, None, "constant");
|
|
}
|
|
}
|
|
|
|
hir::TraitItemKind::Type(_, Some(_)) => {
|
|
tcx.ensure().item_bounds(def_id);
|
|
tcx.ensure().type_of(def_id);
|
|
// Account for `type T = _;`.
|
|
let mut visitor = HirPlaceholderCollector::default();
|
|
visitor.visit_trait_item(trait_item);
|
|
placeholder_type_error(tcx, None, visitor.0, false, None, "associated type");
|
|
}
|
|
|
|
hir::TraitItemKind::Type(_, None) => {
|
|
tcx.ensure().item_bounds(def_id);
|
|
// #74612: Visit and try to find bad placeholders
|
|
// even if there is no concrete type.
|
|
let mut visitor = HirPlaceholderCollector::default();
|
|
visitor.visit_trait_item(trait_item);
|
|
|
|
placeholder_type_error(tcx, None, visitor.0, false, None, "associated type");
|
|
}
|
|
};
|
|
|
|
tcx.ensure().predicates_of(def_id);
|
|
}
|
|
|
|
fn convert_impl_item(tcx: TyCtxt<'_>, impl_item_id: hir::ImplItemId) {
|
|
let def_id = impl_item_id.owner_id;
|
|
tcx.ensure().generics_of(def_id);
|
|
tcx.ensure().type_of(def_id);
|
|
tcx.ensure().predicates_of(def_id);
|
|
let impl_item = tcx.hir().impl_item(impl_item_id);
|
|
match impl_item.kind {
|
|
hir::ImplItemKind::Fn(..) => {
|
|
tcx.ensure().codegen_fn_attrs(def_id);
|
|
tcx.ensure().fn_sig(def_id);
|
|
}
|
|
hir::ImplItemKind::Type(_) => {
|
|
// Account for `type T = _;`
|
|
let mut visitor = HirPlaceholderCollector::default();
|
|
visitor.visit_impl_item(impl_item);
|
|
|
|
placeholder_type_error(tcx, None, visitor.0, false, None, "associated type");
|
|
}
|
|
hir::ImplItemKind::Const(..) => {}
|
|
}
|
|
}
|
|
|
|
fn convert_variant_ctor(tcx: TyCtxt<'_>, def_id: LocalDefId) {
|
|
tcx.ensure().generics_of(def_id);
|
|
tcx.ensure().type_of(def_id);
|
|
tcx.ensure().predicates_of(def_id);
|
|
}
|
|
|
|
fn convert_enum_variant_types(tcx: TyCtxt<'_>, def_id: DefId) {
|
|
let def = tcx.adt_def(def_id);
|
|
let repr_type = def.repr().discr_type();
|
|
let initial = repr_type.initial_discriminant(tcx);
|
|
let mut prev_discr = None::<Discr<'_>>;
|
|
|
|
// fill the discriminant values and field types
|
|
for variant in def.variants() {
|
|
let wrapped_discr = prev_discr.map_or(initial, |d| d.wrap_incr(tcx));
|
|
prev_discr = Some(
|
|
if let ty::VariantDiscr::Explicit(const_def_id) = variant.discr {
|
|
def.eval_explicit_discr(tcx, const_def_id)
|
|
} else if let Some(discr) = repr_type.disr_incr(tcx, prev_discr) {
|
|
Some(discr)
|
|
} else {
|
|
let span = tcx.def_span(variant.def_id);
|
|
tcx.sess.emit_err(errors::EnumDiscriminantOverflowed {
|
|
span,
|
|
discr: prev_discr.unwrap().to_string(),
|
|
item_name: tcx.item_name(variant.def_id),
|
|
wrapped_discr: wrapped_discr.to_string(),
|
|
});
|
|
None
|
|
}
|
|
.unwrap_or(wrapped_discr),
|
|
);
|
|
|
|
for f in &variant.fields {
|
|
tcx.ensure().generics_of(f.did);
|
|
tcx.ensure().type_of(f.did);
|
|
tcx.ensure().predicates_of(f.did);
|
|
}
|
|
|
|
// Convert the ctor, if any. This also registers the variant as
|
|
// an item.
|
|
if let Some(ctor_def_id) = variant.ctor_def_id() {
|
|
convert_variant_ctor(tcx, ctor_def_id.expect_local());
|
|
}
|
|
}
|
|
}
|
|
|
|
fn convert_variant(
|
|
tcx: TyCtxt<'_>,
|
|
variant_did: Option<LocalDefId>,
|
|
ident: Ident,
|
|
discr: ty::VariantDiscr,
|
|
def: &hir::VariantData<'_>,
|
|
adt_kind: ty::AdtKind,
|
|
parent_did: LocalDefId,
|
|
) -> ty::VariantDef {
|
|
let mut seen_fields: FxHashMap<Ident, Span> = Default::default();
|
|
let fields = def
|
|
.fields()
|
|
.iter()
|
|
.map(|f| {
|
|
let dup_span = seen_fields.get(&f.ident.normalize_to_macros_2_0()).cloned();
|
|
if let Some(prev_span) = dup_span {
|
|
tcx.sess.emit_err(errors::FieldAlreadyDeclared {
|
|
field_name: f.ident,
|
|
span: f.span,
|
|
prev_span,
|
|
});
|
|
} else {
|
|
seen_fields.insert(f.ident.normalize_to_macros_2_0(), f.span);
|
|
}
|
|
|
|
ty::FieldDef {
|
|
did: f.def_id.to_def_id(),
|
|
name: f.ident.name,
|
|
vis: tcx.visibility(f.def_id),
|
|
}
|
|
})
|
|
.collect();
|
|
let recovered = match def {
|
|
hir::VariantData::Struct(_, r) => *r,
|
|
_ => false,
|
|
};
|
|
ty::VariantDef::new(
|
|
ident.name,
|
|
variant_did.map(LocalDefId::to_def_id),
|
|
def.ctor().map(|(kind, _, def_id)| (kind, def_id.to_def_id())),
|
|
discr,
|
|
fields,
|
|
adt_kind,
|
|
parent_did.to_def_id(),
|
|
recovered,
|
|
adt_kind == AdtKind::Struct && tcx.has_attr(parent_did, sym::non_exhaustive)
|
|
|| variant_did
|
|
.map_or(false, |variant_did| tcx.has_attr(variant_did, sym::non_exhaustive)),
|
|
)
|
|
}
|
|
|
|
fn adt_def(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::AdtDef<'_> {
|
|
use rustc_hir::*;
|
|
|
|
let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
|
|
let Node::Item(item) = tcx.hir().get(hir_id) else {
|
|
bug!();
|
|
};
|
|
|
|
let repr = tcx.repr_options_of_def(def_id.to_def_id());
|
|
let (kind, variants) = match &item.kind {
|
|
ItemKind::Enum(def, _) => {
|
|
let mut distance_from_explicit = 0;
|
|
let variants = def
|
|
.variants
|
|
.iter()
|
|
.map(|v| {
|
|
let discr = if let Some(e) = &v.disr_expr {
|
|
distance_from_explicit = 0;
|
|
ty::VariantDiscr::Explicit(e.def_id.to_def_id())
|
|
} else {
|
|
ty::VariantDiscr::Relative(distance_from_explicit)
|
|
};
|
|
distance_from_explicit += 1;
|
|
|
|
convert_variant(
|
|
tcx,
|
|
Some(v.def_id),
|
|
v.ident,
|
|
discr,
|
|
&v.data,
|
|
AdtKind::Enum,
|
|
def_id,
|
|
)
|
|
})
|
|
.collect();
|
|
|
|
(AdtKind::Enum, variants)
|
|
}
|
|
ItemKind::Struct(def, _) | ItemKind::Union(def, _) => {
|
|
let adt_kind = match item.kind {
|
|
ItemKind::Struct(..) => AdtKind::Struct,
|
|
_ => AdtKind::Union,
|
|
};
|
|
let variants = std::iter::once(convert_variant(
|
|
tcx,
|
|
None,
|
|
item.ident,
|
|
ty::VariantDiscr::Relative(0),
|
|
def,
|
|
adt_kind,
|
|
def_id,
|
|
))
|
|
.collect();
|
|
|
|
(adt_kind, variants)
|
|
}
|
|
_ => bug!(),
|
|
};
|
|
tcx.mk_adt_def(def_id.to_def_id(), kind, variants, repr)
|
|
}
|
|
|
|
fn trait_def(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::TraitDef {
|
|
let item = tcx.hir().expect_item(def_id);
|
|
|
|
let (is_auto, unsafety, items) = match item.kind {
|
|
hir::ItemKind::Trait(is_auto, unsafety, .., items) => {
|
|
(is_auto == hir::IsAuto::Yes, unsafety, items)
|
|
}
|
|
hir::ItemKind::TraitAlias(..) => (false, hir::Unsafety::Normal, &[][..]),
|
|
_ => span_bug!(item.span, "trait_def_of_item invoked on non-trait"),
|
|
};
|
|
|
|
let paren_sugar = tcx.has_attr(def_id, sym::rustc_paren_sugar);
|
|
if paren_sugar && !tcx.features().unboxed_closures {
|
|
tcx.sess.emit_err(errors::ParenSugarAttribute { span: item.span });
|
|
}
|
|
|
|
let is_marker = tcx.has_attr(def_id, sym::marker);
|
|
let rustc_coinductive = tcx.has_attr(def_id, sym::rustc_coinductive);
|
|
let skip_array_during_method_dispatch =
|
|
tcx.has_attr(def_id, sym::rustc_skip_array_during_method_dispatch);
|
|
let specialization_kind = if tcx.has_attr(def_id, sym::rustc_unsafe_specialization_marker) {
|
|
ty::trait_def::TraitSpecializationKind::Marker
|
|
} else if tcx.has_attr(def_id, sym::rustc_specialization_trait) {
|
|
ty::trait_def::TraitSpecializationKind::AlwaysApplicable
|
|
} else {
|
|
ty::trait_def::TraitSpecializationKind::None
|
|
};
|
|
let must_implement_one_of = tcx
|
|
.get_attr(def_id, sym::rustc_must_implement_one_of)
|
|
// Check that there are at least 2 arguments of `#[rustc_must_implement_one_of]`
|
|
// and that they are all identifiers
|
|
.and_then(|attr| match attr.meta_item_list() {
|
|
Some(items) if items.len() < 2 => {
|
|
tcx.sess.emit_err(errors::MustImplementOneOfAttribute { span: attr.span });
|
|
|
|
None
|
|
}
|
|
Some(items) => items
|
|
.into_iter()
|
|
.map(|item| item.ident().ok_or(item.span()))
|
|
.collect::<Result<Box<[_]>, _>>()
|
|
.map_err(|span| {
|
|
tcx.sess.emit_err(errors::MustBeNameOfAssociatedFunction { span });
|
|
})
|
|
.ok()
|
|
.zip(Some(attr.span)),
|
|
// Error is reported by `rustc_attr!`
|
|
None => None,
|
|
})
|
|
// Check that all arguments of `#[rustc_must_implement_one_of]` reference
|
|
// functions in the trait with default implementations
|
|
.and_then(|(list, attr_span)| {
|
|
let errors = list.iter().filter_map(|ident| {
|
|
let item = items.iter().find(|item| item.ident == *ident);
|
|
|
|
match item {
|
|
Some(item) if matches!(item.kind, hir::AssocItemKind::Fn { .. }) => {
|
|
if !tcx.impl_defaultness(item.id.owner_id).has_value() {
|
|
tcx.sess.emit_err(errors::FunctionNotHaveDefaultImplementation {
|
|
span: item.span,
|
|
note_span: attr_span,
|
|
});
|
|
|
|
return Some(());
|
|
}
|
|
|
|
return None;
|
|
}
|
|
Some(item) => {
|
|
tcx.sess.emit_err(errors::MustImplementNotFunction {
|
|
span: item.span,
|
|
span_note: errors::MustImplementNotFunctionSpanNote { span: attr_span },
|
|
note: errors::MustImplementNotFunctionNote {},
|
|
});
|
|
}
|
|
None => {
|
|
tcx.sess.emit_err(errors::FunctionNotFoundInTrait { span: ident.span });
|
|
}
|
|
}
|
|
|
|
Some(())
|
|
});
|
|
|
|
(errors.count() == 0).then_some(list)
|
|
})
|
|
// Check for duplicates
|
|
.and_then(|list| {
|
|
let mut set: FxHashMap<Symbol, Span> = FxHashMap::default();
|
|
let mut no_dups = true;
|
|
|
|
for ident in &*list {
|
|
if let Some(dup) = set.insert(ident.name, ident.span) {
|
|
tcx.sess
|
|
.emit_err(errors::FunctionNamesDuplicated { spans: vec![dup, ident.span] });
|
|
|
|
no_dups = false;
|
|
}
|
|
}
|
|
|
|
no_dups.then_some(list)
|
|
});
|
|
|
|
ty::TraitDef {
|
|
def_id: def_id.to_def_id(),
|
|
unsafety,
|
|
paren_sugar,
|
|
has_auto_impl: is_auto,
|
|
is_marker,
|
|
is_coinductive: rustc_coinductive || is_auto,
|
|
skip_array_during_method_dispatch,
|
|
specialization_kind,
|
|
must_implement_one_of,
|
|
}
|
|
}
|
|
|
|
fn are_suggestable_generic_args(generic_args: &[hir::GenericArg<'_>]) -> bool {
|
|
generic_args.iter().any(|arg| match arg {
|
|
hir::GenericArg::Type(ty) => is_suggestable_infer_ty(ty),
|
|
hir::GenericArg::Infer(_) => true,
|
|
_ => false,
|
|
})
|
|
}
|
|
|
|
/// Whether `ty` is a type with `_` placeholders that can be inferred. Used in diagnostics only to
|
|
/// use inference to provide suggestions for the appropriate type if possible.
|
|
fn is_suggestable_infer_ty(ty: &hir::Ty<'_>) -> bool {
|
|
debug!(?ty);
|
|
use hir::TyKind::*;
|
|
match &ty.kind {
|
|
Infer => true,
|
|
Slice(ty) => is_suggestable_infer_ty(ty),
|
|
Array(ty, length) => {
|
|
is_suggestable_infer_ty(ty) || matches!(length, hir::ArrayLen::Infer(_, _))
|
|
}
|
|
Tup(tys) => tys.iter().any(is_suggestable_infer_ty),
|
|
Ptr(mut_ty) | Ref(_, mut_ty) => is_suggestable_infer_ty(mut_ty.ty),
|
|
OpaqueDef(_, generic_args, _) => are_suggestable_generic_args(generic_args),
|
|
Path(hir::QPath::TypeRelative(ty, segment)) => {
|
|
is_suggestable_infer_ty(ty) || are_suggestable_generic_args(segment.args().args)
|
|
}
|
|
Path(hir::QPath::Resolved(ty_opt, hir::Path { segments, .. })) => {
|
|
ty_opt.map_or(false, is_suggestable_infer_ty)
|
|
|| segments.iter().any(|segment| are_suggestable_generic_args(segment.args().args))
|
|
}
|
|
_ => false,
|
|
}
|
|
}
|
|
|
|
pub fn get_infer_ret_ty<'hir>(output: &'hir hir::FnRetTy<'hir>) -> Option<&'hir hir::Ty<'hir>> {
|
|
if let hir::FnRetTy::Return(ty) = output {
|
|
if is_suggestable_infer_ty(ty) {
|
|
return Some(&*ty);
|
|
}
|
|
}
|
|
None
|
|
}
|
|
|
|
#[instrument(level = "debug", skip(tcx))]
|
|
fn fn_sig(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::EarlyBinder<ty::PolyFnSig<'_>> {
|
|
use rustc_hir::Node::*;
|
|
use rustc_hir::*;
|
|
|
|
let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
|
|
|
|
let icx = ItemCtxt::new(tcx, def_id);
|
|
|
|
let output = match tcx.hir().get(hir_id) {
|
|
TraitItem(hir::TraitItem {
|
|
kind: TraitItemKind::Fn(sig, TraitFn::Provided(_)),
|
|
generics,
|
|
..
|
|
})
|
|
| Item(hir::Item { kind: ItemKind::Fn(sig, generics, _), .. }) => {
|
|
infer_return_ty_for_fn_sig(tcx, sig, generics, def_id, &icx)
|
|
}
|
|
|
|
ImplItem(hir::ImplItem { kind: ImplItemKind::Fn(sig, _), generics, .. }) => {
|
|
// Do not try to infer the return type for a impl method coming from a trait
|
|
if let Item(hir::Item { kind: ItemKind::Impl(i), .. }) =
|
|
tcx.hir().get_parent(hir_id)
|
|
&& i.of_trait.is_some()
|
|
{
|
|
icx.astconv().ty_of_fn(
|
|
hir_id,
|
|
sig.header.unsafety,
|
|
sig.header.abi,
|
|
sig.decl,
|
|
Some(generics),
|
|
None,
|
|
)
|
|
} else {
|
|
infer_return_ty_for_fn_sig(tcx, sig, generics, def_id, &icx)
|
|
}
|
|
}
|
|
|
|
TraitItem(hir::TraitItem {
|
|
kind: TraitItemKind::Fn(FnSig { header, decl, span: _ }, _),
|
|
generics,
|
|
..
|
|
}) => {
|
|
icx.astconv().ty_of_fn(hir_id, header.unsafety, header.abi, decl, Some(generics), None)
|
|
}
|
|
|
|
ForeignItem(&hir::ForeignItem { kind: ForeignItemKind::Fn(fn_decl, _, _), .. }) => {
|
|
let abi = tcx.hir().get_foreign_abi(hir_id);
|
|
compute_sig_of_foreign_fn_decl(tcx, def_id, fn_decl, abi)
|
|
}
|
|
|
|
Ctor(data) | Variant(hir::Variant { data, .. }) if data.ctor().is_some() => {
|
|
let ty = tcx.type_of(tcx.hir().get_parent_item(hir_id)).subst_identity();
|
|
let inputs = data.fields().iter().map(|f| tcx.type_of(f.def_id).subst_identity());
|
|
ty::Binder::dummy(tcx.mk_fn_sig(
|
|
inputs,
|
|
ty,
|
|
false,
|
|
hir::Unsafety::Normal,
|
|
abi::Abi::Rust,
|
|
))
|
|
}
|
|
|
|
Expr(&hir::Expr { kind: hir::ExprKind::Closure { .. }, .. }) => {
|
|
// Closure signatures are not like other function
|
|
// signatures and cannot be accessed through `fn_sig`. For
|
|
// example, a closure signature excludes the `self`
|
|
// argument. In any case they are embedded within the
|
|
// closure type as part of the `ClosureSubsts`.
|
|
//
|
|
// To get the signature of a closure, you should use the
|
|
// `sig` method on the `ClosureSubsts`:
|
|
//
|
|
// substs.as_closure().sig(def_id, tcx)
|
|
bug!(
|
|
"to get the signature of a closure, use `substs.as_closure().sig()` not `fn_sig()`",
|
|
);
|
|
}
|
|
|
|
x => {
|
|
bug!("unexpected sort of node in fn_sig(): {:?}", x);
|
|
}
|
|
};
|
|
ty::EarlyBinder(output)
|
|
}
|
|
|
|
fn infer_return_ty_for_fn_sig<'tcx>(
|
|
tcx: TyCtxt<'tcx>,
|
|
sig: &hir::FnSig<'_>,
|
|
generics: &hir::Generics<'_>,
|
|
def_id: LocalDefId,
|
|
icx: &ItemCtxt<'tcx>,
|
|
) -> ty::PolyFnSig<'tcx> {
|
|
let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
|
|
|
|
match get_infer_ret_ty(&sig.decl.output) {
|
|
Some(ty) => {
|
|
let fn_sig = tcx.typeck(def_id).liberated_fn_sigs()[hir_id];
|
|
// Typeck doesn't expect erased regions to be returned from `type_of`.
|
|
let fn_sig = tcx.fold_regions(fn_sig, |r, _| match *r {
|
|
ty::ReErased => tcx.lifetimes.re_static,
|
|
_ => r,
|
|
});
|
|
|
|
let mut visitor = HirPlaceholderCollector::default();
|
|
visitor.visit_ty(ty);
|
|
let mut diag = bad_placeholder(tcx, visitor.0, "return type");
|
|
let ret_ty = fn_sig.output();
|
|
if let Some(ret_ty) = ret_ty.make_suggestable(tcx, false) {
|
|
diag.span_suggestion(
|
|
ty.span,
|
|
"replace with the correct return type",
|
|
ret_ty,
|
|
Applicability::MachineApplicable,
|
|
);
|
|
} else if matches!(ret_ty.kind(), ty::FnDef(..))
|
|
&& let Some(fn_sig) = ret_ty.fn_sig(tcx).make_suggestable(tcx, false)
|
|
{
|
|
diag.span_suggestion(
|
|
ty.span,
|
|
"replace with the correct return type",
|
|
fn_sig,
|
|
Applicability::MachineApplicable,
|
|
);
|
|
} else if let Some(sugg) = suggest_impl_trait(tcx, ret_ty, ty.span, def_id) {
|
|
diag.span_suggestion(
|
|
ty.span,
|
|
"replace with an appropriate return type",
|
|
sugg,
|
|
Applicability::MachineApplicable,
|
|
);
|
|
} else if ret_ty.is_closure() {
|
|
diag.help("consider using an `Fn`, `FnMut`, or `FnOnce` trait bound");
|
|
}
|
|
// Also note how `Fn` traits work just in case!
|
|
if ret_ty.is_closure() {
|
|
diag.note(
|
|
"for more information on `Fn` traits and closure types, see \
|
|
https://doc.rust-lang.org/book/ch13-01-closures.html",
|
|
);
|
|
}
|
|
diag.emit();
|
|
|
|
ty::Binder::dummy(fn_sig)
|
|
}
|
|
None => icx.astconv().ty_of_fn(
|
|
hir_id,
|
|
sig.header.unsafety,
|
|
sig.header.abi,
|
|
sig.decl,
|
|
Some(generics),
|
|
None,
|
|
),
|
|
}
|
|
}
|
|
|
|
fn suggest_impl_trait<'tcx>(
|
|
tcx: TyCtxt<'tcx>,
|
|
ret_ty: Ty<'tcx>,
|
|
span: Span,
|
|
def_id: LocalDefId,
|
|
) -> Option<String> {
|
|
let format_as_assoc: fn(_, _, _, _, _) -> _ =
|
|
|tcx: TyCtxt<'tcx>,
|
|
_: ty::SubstsRef<'tcx>,
|
|
trait_def_id: DefId,
|
|
assoc_item_def_id: DefId,
|
|
item_ty: Ty<'tcx>| {
|
|
let trait_name = tcx.item_name(trait_def_id);
|
|
let assoc_name = tcx.item_name(assoc_item_def_id);
|
|
Some(format!("impl {trait_name}<{assoc_name} = {item_ty}>"))
|
|
};
|
|
let format_as_parenthesized: fn(_, _, _, _, _) -> _ =
|
|
|tcx: TyCtxt<'tcx>,
|
|
substs: ty::SubstsRef<'tcx>,
|
|
trait_def_id: DefId,
|
|
_: DefId,
|
|
item_ty: Ty<'tcx>| {
|
|
let trait_name = tcx.item_name(trait_def_id);
|
|
let args_tuple = substs.type_at(1);
|
|
let ty::Tuple(types) = *args_tuple.kind() else { return None; };
|
|
let types = types.make_suggestable(tcx, false)?;
|
|
let maybe_ret =
|
|
if item_ty.is_unit() { String::new() } else { format!(" -> {item_ty}") };
|
|
Some(format!(
|
|
"impl {trait_name}({}){maybe_ret}",
|
|
types.iter().map(|ty| ty.to_string()).collect::<Vec<_>>().join(", ")
|
|
))
|
|
};
|
|
|
|
for (trait_def_id, assoc_item_def_id, formatter) in [
|
|
(
|
|
tcx.get_diagnostic_item(sym::Iterator),
|
|
tcx.get_diagnostic_item(sym::IteratorItem),
|
|
format_as_assoc,
|
|
),
|
|
(
|
|
tcx.lang_items().future_trait(),
|
|
tcx.get_diagnostic_item(sym::FutureOutput),
|
|
format_as_assoc,
|
|
),
|
|
(tcx.lang_items().fn_trait(), tcx.lang_items().fn_once_output(), format_as_parenthesized),
|
|
(
|
|
tcx.lang_items().fn_mut_trait(),
|
|
tcx.lang_items().fn_once_output(),
|
|
format_as_parenthesized,
|
|
),
|
|
(
|
|
tcx.lang_items().fn_once_trait(),
|
|
tcx.lang_items().fn_once_output(),
|
|
format_as_parenthesized,
|
|
),
|
|
] {
|
|
let Some(trait_def_id) = trait_def_id else { continue; };
|
|
let Some(assoc_item_def_id) = assoc_item_def_id else { continue; };
|
|
if tcx.def_kind(assoc_item_def_id) != DefKind::AssocTy {
|
|
continue;
|
|
}
|
|
let param_env = tcx.param_env(def_id);
|
|
let infcx = tcx.infer_ctxt().build();
|
|
let substs = ty::InternalSubsts::for_item(tcx, trait_def_id, |param, _| {
|
|
if param.index == 0 { ret_ty.into() } else { infcx.var_for_def(span, param) }
|
|
});
|
|
if !infcx.type_implements_trait(trait_def_id, substs, param_env).must_apply_modulo_regions()
|
|
{
|
|
continue;
|
|
}
|
|
let ocx = ObligationCtxt::new_in_snapshot(&infcx);
|
|
let item_ty = ocx.normalize(
|
|
&ObligationCause::misc(span, def_id),
|
|
param_env,
|
|
tcx.mk_projection(assoc_item_def_id, substs),
|
|
);
|
|
// FIXME(compiler-errors): We may benefit from resolving regions here.
|
|
if ocx.select_where_possible().is_empty()
|
|
&& let item_ty = infcx.resolve_vars_if_possible(item_ty)
|
|
&& let Some(item_ty) = item_ty.make_suggestable(tcx, false)
|
|
&& let Some(sugg) = formatter(tcx, infcx.resolve_vars_if_possible(substs), trait_def_id, assoc_item_def_id, item_ty)
|
|
{
|
|
return Some(sugg);
|
|
}
|
|
}
|
|
None
|
|
}
|
|
|
|
fn impl_trait_ref(
|
|
tcx: TyCtxt<'_>,
|
|
def_id: LocalDefId,
|
|
) -> Option<ty::EarlyBinder<ty::TraitRef<'_>>> {
|
|
let icx = ItemCtxt::new(tcx, def_id);
|
|
let impl_ = tcx.hir().expect_item(def_id).expect_impl();
|
|
impl_
|
|
.of_trait
|
|
.as_ref()
|
|
.map(|ast_trait_ref| {
|
|
let selfty = tcx.type_of(def_id).subst_identity();
|
|
icx.astconv().instantiate_mono_trait_ref(
|
|
ast_trait_ref,
|
|
selfty,
|
|
check_impl_constness(tcx, impl_.constness, ast_trait_ref),
|
|
)
|
|
})
|
|
.map(ty::EarlyBinder)
|
|
}
|
|
|
|
fn check_impl_constness(
|
|
tcx: TyCtxt<'_>,
|
|
constness: hir::Constness,
|
|
ast_trait_ref: &hir::TraitRef<'_>,
|
|
) -> ty::BoundConstness {
|
|
match constness {
|
|
hir::Constness::Const => {
|
|
if let Some(trait_def_id) = ast_trait_ref.trait_def_id() && !tcx.has_attr(trait_def_id, sym::const_trait) {
|
|
let trait_name = tcx.item_name(trait_def_id).to_string();
|
|
tcx.sess.emit_err(errors::ConstImplForNonConstTrait {
|
|
trait_ref_span: ast_trait_ref.path.span,
|
|
trait_name,
|
|
local_trait_span: trait_def_id.as_local().map(|_| tcx.def_span(trait_def_id).shrink_to_lo()),
|
|
marking: (),
|
|
adding: (),
|
|
});
|
|
ty::BoundConstness::NotConst
|
|
} else {
|
|
ty::BoundConstness::ConstIfConst
|
|
}
|
|
},
|
|
hir::Constness::NotConst => ty::BoundConstness::NotConst,
|
|
}
|
|
}
|
|
|
|
fn impl_polarity(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::ImplPolarity {
|
|
let is_rustc_reservation = tcx.has_attr(def_id, sym::rustc_reservation_impl);
|
|
let item = tcx.hir().expect_item(def_id);
|
|
match &item.kind {
|
|
hir::ItemKind::Impl(hir::Impl {
|
|
polarity: hir::ImplPolarity::Negative(span),
|
|
of_trait,
|
|
..
|
|
}) => {
|
|
if is_rustc_reservation {
|
|
let span = span.to(of_trait.as_ref().map_or(*span, |t| t.path.span));
|
|
tcx.sess.span_err(span, "reservation impls can't be negative");
|
|
}
|
|
ty::ImplPolarity::Negative
|
|
}
|
|
hir::ItemKind::Impl(hir::Impl {
|
|
polarity: hir::ImplPolarity::Positive,
|
|
of_trait: None,
|
|
..
|
|
}) => {
|
|
if is_rustc_reservation {
|
|
tcx.sess.span_err(item.span, "reservation impls can't be inherent");
|
|
}
|
|
ty::ImplPolarity::Positive
|
|
}
|
|
hir::ItemKind::Impl(hir::Impl {
|
|
polarity: hir::ImplPolarity::Positive,
|
|
of_trait: Some(_),
|
|
..
|
|
}) => {
|
|
if is_rustc_reservation {
|
|
ty::ImplPolarity::Reservation
|
|
} else {
|
|
ty::ImplPolarity::Positive
|
|
}
|
|
}
|
|
item => bug!("impl_polarity: {:?} not an impl", item),
|
|
}
|
|
}
|
|
|
|
/// Returns the early-bound lifetimes declared in this generics
|
|
/// listing. For anything other than fns/methods, this is just all
|
|
/// the lifetimes that are declared. For fns or methods, we have to
|
|
/// screen out those that do not appear in any where-clauses etc using
|
|
/// `resolve_lifetime::early_bound_lifetimes`.
|
|
fn early_bound_lifetimes_from_generics<'a, 'tcx: 'a>(
|
|
tcx: TyCtxt<'tcx>,
|
|
generics: &'a hir::Generics<'a>,
|
|
) -> impl Iterator<Item = &'a hir::GenericParam<'a>> + Captures<'tcx> {
|
|
generics.params.iter().filter(move |param| match param.kind {
|
|
GenericParamKind::Lifetime { .. } => !tcx.is_late_bound(param.hir_id),
|
|
_ => false,
|
|
})
|
|
}
|
|
|
|
/// Returns a list of type predicates for the definition with ID `def_id`, including inferred
|
|
/// lifetime constraints. This includes all predicates returned by `explicit_predicates_of`, plus
|
|
/// inferred constraints concerning which regions outlive other regions.
|
|
#[instrument(level = "debug", skip(tcx))]
|
|
fn predicates_defined_on(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericPredicates<'_> {
|
|
let mut result = tcx.explicit_predicates_of(def_id);
|
|
debug!("predicates_defined_on: explicit_predicates_of({:?}) = {:?}", def_id, result,);
|
|
let inferred_outlives = tcx.inferred_outlives_of(def_id);
|
|
if !inferred_outlives.is_empty() {
|
|
debug!(
|
|
"predicates_defined_on: inferred_outlives_of({:?}) = {:?}",
|
|
def_id, inferred_outlives,
|
|
);
|
|
let inferred_outlives_iter =
|
|
inferred_outlives.iter().map(|(clause, span)| ((*clause).to_predicate(tcx), *span));
|
|
if result.predicates.is_empty() {
|
|
result.predicates = tcx.arena.alloc_from_iter(inferred_outlives_iter);
|
|
} else {
|
|
result.predicates = tcx.arena.alloc_from_iter(
|
|
result.predicates.into_iter().copied().chain(inferred_outlives_iter),
|
|
);
|
|
}
|
|
}
|
|
|
|
debug!("predicates_defined_on({:?}) = {:?}", def_id, result);
|
|
result
|
|
}
|
|
|
|
fn compute_sig_of_foreign_fn_decl<'tcx>(
|
|
tcx: TyCtxt<'tcx>,
|
|
def_id: LocalDefId,
|
|
decl: &'tcx hir::FnDecl<'tcx>,
|
|
abi: abi::Abi,
|
|
) -> ty::PolyFnSig<'tcx> {
|
|
let unsafety = if abi == abi::Abi::RustIntrinsic {
|
|
intrinsic_operation_unsafety(tcx, def_id.to_def_id())
|
|
} else {
|
|
hir::Unsafety::Unsafe
|
|
};
|
|
let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
|
|
let fty =
|
|
ItemCtxt::new(tcx, def_id).astconv().ty_of_fn(hir_id, unsafety, abi, decl, None, None);
|
|
|
|
// Feature gate SIMD types in FFI, since I am not sure that the
|
|
// ABIs are handled at all correctly. -huonw
|
|
if abi != abi::Abi::RustIntrinsic
|
|
&& abi != abi::Abi::PlatformIntrinsic
|
|
&& !tcx.features().simd_ffi
|
|
{
|
|
let check = |ast_ty: &hir::Ty<'_>, ty: Ty<'_>| {
|
|
if ty.is_simd() {
|
|
let snip = tcx
|
|
.sess
|
|
.source_map()
|
|
.span_to_snippet(ast_ty.span)
|
|
.map_or_else(|_| String::new(), |s| format!(" `{}`", s));
|
|
tcx.sess.emit_err(errors::SIMDFFIHighlyExperimental { span: ast_ty.span, snip });
|
|
}
|
|
};
|
|
for (input, ty) in iter::zip(decl.inputs, fty.inputs().skip_binder()) {
|
|
check(input, *ty)
|
|
}
|
|
if let hir::FnRetTy::Return(ty) = decl.output {
|
|
check(ty, fty.output().skip_binder())
|
|
}
|
|
}
|
|
|
|
fty
|
|
}
|
|
|
|
fn is_foreign_item(tcx: TyCtxt<'_>, def_id: LocalDefId) -> bool {
|
|
match tcx.hir().get_by_def_id(def_id) {
|
|
Node::ForeignItem(..) => true,
|
|
_ => false,
|
|
}
|
|
}
|
|
|
|
fn generator_kind(tcx: TyCtxt<'_>, def_id: LocalDefId) -> Option<hir::GeneratorKind> {
|
|
match tcx.hir().get_by_def_id(def_id) {
|
|
Node::Expr(&rustc_hir::Expr {
|
|
kind: rustc_hir::ExprKind::Closure(&rustc_hir::Closure { body, .. }),
|
|
..
|
|
}) => tcx.hir().body(body).generator_kind(),
|
|
_ => None,
|
|
}
|
|
}
|
|
|
|
fn is_type_alias_impl_trait<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> bool {
|
|
match tcx.hir().get_by_def_id(def_id) {
|
|
Node::Item(hir::Item { kind: hir::ItemKind::OpaqueTy(opaque), .. }) => {
|
|
matches!(opaque.origin, hir::OpaqueTyOrigin::TyAlias)
|
|
}
|
|
_ => bug!("tried getting opaque_ty_origin for non-opaque: {:?}", def_id),
|
|
}
|
|
}
|