3403 lines
135 KiB
Rust
3403 lines
135 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::bounds::Bounds;
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use crate::check::intrinsic::intrinsic_operation_unsafety;
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use crate::constrained_generic_params as cgp;
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use crate::errors;
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use crate::middle::resolve_lifetime as rl;
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use rustc_ast as ast;
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use rustc_ast::{MetaItemKind, NestedMetaItem};
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use rustc_attr::{list_contains_name, InlineAttr, InstructionSetAttr, OptimizeAttr};
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use rustc_data_structures::captures::Captures;
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use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexSet};
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use rustc_errors::{struct_span_err, Applicability, DiagnosticBuilder, ErrorGuaranteed, StashKey};
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use rustc_hir as hir;
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use rustc_hir::def::{CtorKind, DefKind};
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use rustc_hir::def_id::{DefId, LocalDefId, LOCAL_CRATE};
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use rustc_hir::intravisit::{self, Visitor};
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use rustc_hir::weak_lang_items;
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use rustc_hir::{GenericParamKind, HirId, Node};
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use rustc_middle::hir::nested_filter;
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use rustc_middle::middle::codegen_fn_attrs::{CodegenFnAttrFlags, CodegenFnAttrs};
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use rustc_middle::mir::mono::Linkage;
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use rustc_middle::ty::query::Providers;
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use rustc_middle::ty::subst::InternalSubsts;
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use rustc_middle::ty::util::Discr;
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use rustc_middle::ty::util::IntTypeExt;
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use rustc_middle::ty::{self, AdtKind, Const, DefIdTree, IsSuggestable, Ty, TyCtxt};
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use rustc_middle::ty::{ReprOptions, ToPredicate};
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use rustc_session::lint;
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use rustc_session::parse::feature_err;
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use rustc_span::symbol::{kw, sym, Ident, Symbol};
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use rustc_span::{Span, DUMMY_SP};
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use rustc_target::spec::{abi, SanitizerSet};
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use rustc_trait_selection::traits::error_reporting::suggestions::NextTypeParamName;
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use std::iter;
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mod item_bounds;
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mod type_of;
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#[derive(Debug)]
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struct OnlySelfBounds(bool);
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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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*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,
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predicates_of,
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predicates_defined_on,
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explicit_predicates_of,
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super_predicates_of,
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super_predicates_that_define_assoc_type,
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trait_explicit_predicates_and_bounds,
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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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codegen_fn_attrs,
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asm_target_features,
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collect_mod_item_types,
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should_inherit_track_caller,
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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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/// [`FnCtxt`]: crate::check::FnCtxt
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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: DefId,
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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().get_parent_node(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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let def_id = self.tcx.hir().local_def_id(param.hir_id);
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self.tcx.ensure().type_of(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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let def_id = self.tcx.hir().local_def_id(param.hir_id);
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self.tcx.ensure().type_of(def_id);
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if let Some(default) = default {
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let default_def_id = self.tcx.hir().local_def_id(default.hir_id);
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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(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 { .. } = expr.kind {
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let def_id = self.tcx.hir().local_def_id(expr.hir_id);
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self.tcx.ensure().generics_of(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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|
let mut err = struct_span_err!(
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tcx.sess,
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spans.clone(),
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E0121,
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"the placeholder `_` is not allowed within types on item signatures for {}",
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kind
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);
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for span in spans {
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err.span_label(span, "not allowed in type signatures");
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}
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err
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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: DefId) -> 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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<dyn AstConv<'_>>::ast_ty_to_ty(self, ast_ty)
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}
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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.expect_local())
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}
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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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|
}
|
|
|
|
fn item_def_id(&self) -> Option<DefId> {
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|
Some(self.item_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: DefId,
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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((
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|
self.item_def_id,
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|
def_id.expect_local(),
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|
assoc_name,
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|
))
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|
}
|
|
|
|
fn re_infer(&self, _: Option<&ty::GenericParamDef>, _: Span) -> Option<ty::Region<'tcx>> {
|
|
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> {
|
|
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> {
|
|
let ty = self.tcx.fold_regions(ty, |r, _| match *r {
|
|
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>,
|
|
) -> Ty<'tcx> {
|
|
if let Some(trait_ref) = poly_trait_ref.no_bound_vars() {
|
|
let item_substs = <dyn AstConv<'tcx>>::create_substs_for_associated_item(
|
|
self,
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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 err = struct_span_err!(
|
|
self.tcx().sess,
|
|
span,
|
|
E0212,
|
|
"cannot use the associated type of a trait \
|
|
with uninferred generic parameters"
|
|
);
|
|
|
|
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 {
|
|
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))
|
|
}
|
|
};
|
|
let suggestions = vec![
|
|
(lt_sp, sugg),
|
|
(
|
|
span.with_hi(item_segment.ident.span.lo()),
|
|
format!(
|
|
"{}::",
|
|
// Replace the existing lifetimes with a new named lifetime.
|
|
self.tcx.replace_late_bound_regions_uncached(
|
|
poly_trait_ref,
|
|
|_| {
|
|
self.tcx.mk_region(ty::ReEarlyBound(
|
|
ty::EarlyBoundRegion {
|
|
def_id: item_def_id,
|
|
index: 0,
|
|
name: Symbol::intern(<_name),
|
|
},
|
|
))
|
|
}
|
|
),
|
|
),
|
|
),
|
|
];
|
|
err.multipart_suggestion(
|
|
"use a fully qualified path with explicit lifetimes",
|
|
suggestions,
|
|
Applicability::MaybeIncorrect,
|
|
);
|
|
}
|
|
_ => {}
|
|
}
|
|
}
|
|
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(_) => {
|
|
err.span_suggestion_verbose(
|
|
span.with_hi(item_segment.ident.span.lo()),
|
|
"use a fully qualified path with inferred lifetimes",
|
|
format!(
|
|
"{}::",
|
|
// Erase named lt, we want `<A as B<'_>::C`, not `<A as B<'a>::C`.
|
|
self.tcx.anonymize_late_bound_regions(poly_trait_ref).skip_binder(),
|
|
),
|
|
Applicability::MaybeIncorrect,
|
|
);
|
|
}
|
|
_ => {}
|
|
}
|
|
err.emit();
|
|
self.tcx().ty_error()
|
|
}
|
|
}
|
|
|
|
fn normalize_ty(&self, _span: Span, ty: Ty<'tcx>) -> Ty<'tcx> {
|
|
// Types in item signatures are not normalized to avoid undue dependencies.
|
|
ty
|
|
}
|
|
|
|
fn set_tainted_by_errors(&self) {
|
|
// 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?
|
|
}
|
|
}
|
|
|
|
/// 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()
|
|
}
|
|
|
|
/// Returns the predicates defined on `item_def_id` of the form
|
|
/// `X: Foo` where `X` is the type parameter `def_id`.
|
|
#[instrument(level = "trace", skip(tcx))]
|
|
fn type_param_predicates(
|
|
tcx: TyCtxt<'_>,
|
|
(item_def_id, def_id, assoc_name): (DefId, LocalDefId, Ident),
|
|
) -> ty::GenericPredicates<'_> {
|
|
use rustc_hir::*;
|
|
|
|
// In the AST, bounds can derive from two places. Either
|
|
// written inline like `<T: Foo>` or in a where-clause like
|
|
// `where T: Foo`.
|
|
|
|
let param_id = tcx.hir().local_def_id_to_hir_id(def_id);
|
|
let param_owner = tcx.hir().ty_param_owner(def_id);
|
|
let generics = tcx.generics_of(param_owner);
|
|
let index = generics.param_def_id_to_index[&def_id.to_def_id()];
|
|
let ty = tcx.mk_ty_param(index, tcx.hir().ty_param_name(def_id));
|
|
|
|
// Don't look for bounds where the type parameter isn't in scope.
|
|
let parent = if item_def_id == param_owner.to_def_id() {
|
|
None
|
|
} else {
|
|
tcx.generics_of(item_def_id).parent
|
|
};
|
|
|
|
let mut result = parent
|
|
.map(|parent| {
|
|
let icx = ItemCtxt::new(tcx, parent);
|
|
icx.get_type_parameter_bounds(DUMMY_SP, def_id.to_def_id(), assoc_name)
|
|
})
|
|
.unwrap_or_default();
|
|
let mut extend = None;
|
|
|
|
let item_hir_id = tcx.hir().local_def_id_to_hir_id(item_def_id.expect_local());
|
|
let ast_generics = match tcx.hir().get(item_hir_id) {
|
|
Node::TraitItem(item) => &item.generics,
|
|
|
|
Node::ImplItem(item) => &item.generics,
|
|
|
|
Node::Item(item) => {
|
|
match item.kind {
|
|
ItemKind::Fn(.., ref generics, _)
|
|
| ItemKind::Impl(hir::Impl { ref generics, .. })
|
|
| ItemKind::TyAlias(_, ref generics)
|
|
| ItemKind::OpaqueTy(OpaqueTy {
|
|
ref generics,
|
|
origin: hir::OpaqueTyOrigin::TyAlias,
|
|
..
|
|
})
|
|
| ItemKind::Enum(_, ref generics)
|
|
| ItemKind::Struct(_, ref generics)
|
|
| ItemKind::Union(_, ref generics) => generics,
|
|
ItemKind::Trait(_, _, ref generics, ..) => {
|
|
// Implied `Self: Trait` and supertrait bounds.
|
|
if param_id == item_hir_id {
|
|
let identity_trait_ref = ty::TraitRef::identity(tcx, item_def_id);
|
|
extend =
|
|
Some((identity_trait_ref.without_const().to_predicate(tcx), item.span));
|
|
}
|
|
generics
|
|
}
|
|
_ => return result,
|
|
}
|
|
}
|
|
|
|
Node::ForeignItem(item) => match item.kind {
|
|
ForeignItemKind::Fn(_, _, ref generics) => generics,
|
|
_ => return result,
|
|
},
|
|
|
|
_ => return result,
|
|
};
|
|
|
|
let icx = ItemCtxt::new(tcx, item_def_id);
|
|
let extra_predicates = extend.into_iter().chain(
|
|
icx.type_parameter_bounds_in_generics(
|
|
ast_generics,
|
|
param_id,
|
|
ty,
|
|
OnlySelfBounds(true),
|
|
Some(assoc_name),
|
|
)
|
|
.into_iter()
|
|
.filter(|(predicate, _)| match predicate.kind().skip_binder() {
|
|
ty::PredicateKind::Trait(data) => data.self_ty().is_param(index),
|
|
_ => false,
|
|
}),
|
|
);
|
|
result.predicates =
|
|
tcx.arena.alloc_from_iter(result.predicates.iter().copied().chain(extra_predicates));
|
|
result
|
|
}
|
|
|
|
impl<'tcx> ItemCtxt<'tcx> {
|
|
/// Finds bounds from `hir::Generics`. This requires scanning through the
|
|
/// AST. We do this to avoid having to convert *all* the bounds, which
|
|
/// would create artificial cycles. Instead, we can only convert the
|
|
/// bounds for a type parameter `X` if `X::Foo` is used.
|
|
#[instrument(level = "trace", skip(self, ast_generics))]
|
|
fn type_parameter_bounds_in_generics(
|
|
&self,
|
|
ast_generics: &'tcx hir::Generics<'tcx>,
|
|
param_id: hir::HirId,
|
|
ty: Ty<'tcx>,
|
|
only_self_bounds: OnlySelfBounds,
|
|
assoc_name: Option<Ident>,
|
|
) -> Vec<(ty::Predicate<'tcx>, Span)> {
|
|
let param_def_id = self.tcx.hir().local_def_id(param_id).to_def_id();
|
|
trace!(?param_def_id);
|
|
ast_generics
|
|
.predicates
|
|
.iter()
|
|
.filter_map(|wp| match *wp {
|
|
hir::WherePredicate::BoundPredicate(ref bp) => Some(bp),
|
|
_ => None,
|
|
})
|
|
.flat_map(|bp| {
|
|
let bt = if bp.is_param_bound(param_def_id) {
|
|
Some(ty)
|
|
} else if !only_self_bounds.0 {
|
|
Some(self.to_ty(bp.bounded_ty))
|
|
} else {
|
|
None
|
|
};
|
|
let bvars = self.tcx.late_bound_vars(bp.bounded_ty.hir_id);
|
|
|
|
bp.bounds.iter().filter_map(move |b| bt.map(|bt| (bt, b, bvars))).filter(
|
|
|(_, b, _)| match assoc_name {
|
|
Some(assoc_name) => self.bound_defines_assoc_item(b, assoc_name),
|
|
None => true,
|
|
},
|
|
)
|
|
})
|
|
.flat_map(|(bt, b, bvars)| predicates_from_bound(self, bt, b, bvars))
|
|
.collect()
|
|
}
|
|
|
|
#[instrument(level = "trace", skip(self))]
|
|
fn bound_defines_assoc_item(&self, b: &hir::GenericBound<'_>, assoc_name: Ident) -> bool {
|
|
match b {
|
|
hir::GenericBound::Trait(poly_trait_ref, _) => {
|
|
let trait_ref = &poly_trait_ref.trait_ref;
|
|
if let Some(trait_did) = trait_ref.trait_def_id() {
|
|
self.tcx.trait_may_define_assoc_type(trait_did, assoc_name)
|
|
} else {
|
|
false
|
|
}
|
|
}
|
|
_ => false,
|
|
}
|
|
}
|
|
}
|
|
|
|
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.def_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.def_id);
|
|
tcx.ensure().type_of(item.def_id);
|
|
tcx.ensure().predicates_of(item.def_id);
|
|
match item.kind {
|
|
hir::ForeignItemKind::Fn(..) => tcx.ensure().fn_sig(item.def_id),
|
|
hir::ForeignItemKind::Static(..) => {
|
|
let mut visitor = HirPlaceholderCollector::default();
|
|
visitor.visit_foreign_item(item);
|
|
placeholder_type_error(
|
|
tcx,
|
|
None,
|
|
visitor.0,
|
|
false,
|
|
None,
|
|
"static variable",
|
|
);
|
|
}
|
|
_ => (),
|
|
}
|
|
}
|
|
}
|
|
hir::ItemKind::Enum(ref enum_definition, _) => {
|
|
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(), enum_definition.variants);
|
|
}
|
|
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(ref struct_def, _) | hir::ItemKind::Union(ref 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() {
|
|
let def_id = tcx.hir().local_def_id(f.hir_id);
|
|
tcx.ensure().generics_of(def_id);
|
|
tcx.ensure().type_of(def_id);
|
|
tcx.ensure().predicates_of(def_id);
|
|
}
|
|
|
|
if let Some(ctor_hir_id) = struct_def.ctor_hir_id() {
|
|
convert_variant_ctor(tcx, ctor_hir_id);
|
|
}
|
|
}
|
|
|
|
// Desugared from `impl Trait`, so visited by the function's return type.
|
|
hir::ItemKind::OpaqueTy(hir::OpaqueTy {
|
|
origin: hir::OpaqueTyOrigin::FnReturn(..) | hir::OpaqueTyOrigin::AsyncFn(..),
|
|
..
|
|
}) => {}
|
|
|
|
// 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);
|
|
}
|
|
hir::ItemKind::TyAlias(..)
|
|
| hir::ItemKind::Static(..)
|
|
| hir::ItemKind::Const(..)
|
|
| hir::ItemKind::Fn(..) => {
|
|
tcx.ensure().generics_of(def_id);
|
|
tcx.ensure().type_of(def_id);
|
|
tcx.ensure().predicates_of(def_id);
|
|
match it.kind {
|
|
hir::ItemKind::Fn(..) => tcx.ensure().fn_sig(def_id),
|
|
hir::ItemKind::OpaqueTy(..) => tcx.ensure().item_bounds(def_id),
|
|
hir::ItemKind::Const(ty, ..) | hir::ItemKind::Static(ty, ..) => {
|
|
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());
|
|
}
|
|
}
|
|
_ => (),
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
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.def_id;
|
|
tcx.ensure().generics_of(def_id);
|
|
|
|
match trait_item.kind {
|
|
hir::TraitItemKind::Fn(..) => {
|
|
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.def_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().fn_sig(def_id);
|
|
}
|
|
hir::ImplItemKind::TyAlias(_) => {
|
|
// 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<'_>, ctor_id: hir::HirId) {
|
|
let def_id = tcx.hir().local_def_id(ctor_id);
|
|
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, variants: &[hir::Variant<'_>]) {
|
|
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 variants {
|
|
let wrapped_discr = prev_discr.map_or(initial, |d| d.wrap_incr(tcx));
|
|
prev_discr = Some(
|
|
if let Some(ref e) = variant.disr_expr {
|
|
let expr_did = tcx.hir().local_def_id(e.hir_id);
|
|
def.eval_explicit_discr(tcx, expr_did.to_def_id())
|
|
} else if let Some(discr) = repr_type.disr_incr(tcx, prev_discr) {
|
|
Some(discr)
|
|
} else {
|
|
struct_span_err!(tcx.sess, variant.span, E0370, "enum discriminant overflowed")
|
|
.span_label(
|
|
variant.span,
|
|
format!("overflowed on value after {}", prev_discr.unwrap()),
|
|
)
|
|
.note(&format!(
|
|
"explicitly set `{} = {}` if that is desired outcome",
|
|
variant.ident, wrapped_discr
|
|
))
|
|
.emit();
|
|
None
|
|
}
|
|
.unwrap_or(wrapped_discr),
|
|
);
|
|
|
|
for f in variant.data.fields() {
|
|
let def_id = tcx.hir().local_def_id(f.hir_id);
|
|
tcx.ensure().generics_of(def_id);
|
|
tcx.ensure().type_of(def_id);
|
|
tcx.ensure().predicates_of(def_id);
|
|
}
|
|
|
|
// Convert the ctor, if any. This also registers the variant as
|
|
// an item.
|
|
if let Some(ctor_hir_id) = variant.data.ctor_hir_id() {
|
|
convert_variant_ctor(tcx, ctor_hir_id);
|
|
}
|
|
}
|
|
}
|
|
|
|
fn convert_variant(
|
|
tcx: TyCtxt<'_>,
|
|
variant_did: Option<LocalDefId>,
|
|
ctor_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 fid = tcx.hir().local_def_id(f.hir_id);
|
|
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: fid.to_def_id(), name: f.ident.name, vis: tcx.visibility(fid) }
|
|
})
|
|
.collect();
|
|
let recovered = match def {
|
|
hir::VariantData::Struct(_, r) => *r,
|
|
_ => false,
|
|
};
|
|
ty::VariantDef::new(
|
|
ident.name,
|
|
variant_did.map(LocalDefId::to_def_id),
|
|
ctor_did.map(LocalDefId::to_def_id),
|
|
discr,
|
|
fields,
|
|
CtorKind::from_hir(def),
|
|
adt_kind,
|
|
parent_did.to_def_id(),
|
|
recovered,
|
|
adt_kind == AdtKind::Struct && tcx.has_attr(parent_did.to_def_id(), sym::non_exhaustive)
|
|
|| variant_did.map_or(false, |variant_did| {
|
|
tcx.has_attr(variant_did.to_def_id(), sym::non_exhaustive)
|
|
}),
|
|
)
|
|
}
|
|
|
|
fn adt_def<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> ty::AdtDef<'tcx> {
|
|
use rustc_hir::*;
|
|
|
|
let def_id = def_id.expect_local();
|
|
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 = ReprOptions::new(tcx, def_id.to_def_id());
|
|
let (kind, variants) = match item.kind {
|
|
ItemKind::Enum(ref def, _) => {
|
|
let mut distance_from_explicit = 0;
|
|
let variants = def
|
|
.variants
|
|
.iter()
|
|
.map(|v| {
|
|
let variant_did = Some(tcx.hir().local_def_id(v.id));
|
|
let ctor_did =
|
|
v.data.ctor_hir_id().map(|hir_id| tcx.hir().local_def_id(hir_id));
|
|
|
|
let discr = if let Some(ref e) = v.disr_expr {
|
|
distance_from_explicit = 0;
|
|
ty::VariantDiscr::Explicit(tcx.hir().local_def_id(e.hir_id).to_def_id())
|
|
} else {
|
|
ty::VariantDiscr::Relative(distance_from_explicit)
|
|
};
|
|
distance_from_explicit += 1;
|
|
|
|
convert_variant(
|
|
tcx,
|
|
variant_did,
|
|
ctor_did,
|
|
v.ident,
|
|
discr,
|
|
&v.data,
|
|
AdtKind::Enum,
|
|
def_id,
|
|
)
|
|
})
|
|
.collect();
|
|
|
|
(AdtKind::Enum, variants)
|
|
}
|
|
ItemKind::Struct(ref def, _) => {
|
|
let variant_did = None::<LocalDefId>;
|
|
let ctor_did = def.ctor_hir_id().map(|hir_id| tcx.hir().local_def_id(hir_id));
|
|
|
|
let variants = std::iter::once(convert_variant(
|
|
tcx,
|
|
variant_did,
|
|
ctor_did,
|
|
item.ident,
|
|
ty::VariantDiscr::Relative(0),
|
|
def,
|
|
AdtKind::Struct,
|
|
def_id,
|
|
))
|
|
.collect();
|
|
|
|
(AdtKind::Struct, variants)
|
|
}
|
|
ItemKind::Union(ref def, _) => {
|
|
let variant_did = None;
|
|
let ctor_did = def.ctor_hir_id().map(|hir_id| tcx.hir().local_def_id(hir_id));
|
|
|
|
let variants = std::iter::once(convert_variant(
|
|
tcx,
|
|
variant_did,
|
|
ctor_did,
|
|
item.ident,
|
|
ty::VariantDiscr::Relative(0),
|
|
def,
|
|
AdtKind::Union,
|
|
def_id,
|
|
))
|
|
.collect();
|
|
|
|
(AdtKind::Union, variants)
|
|
}
|
|
_ => bug!(),
|
|
};
|
|
tcx.alloc_adt_def(def_id.to_def_id(), kind, variants, repr)
|
|
}
|
|
|
|
/// Ensures that the super-predicates of the trait with a `DefId`
|
|
/// of `trait_def_id` are converted and stored. This also ensures that
|
|
/// the transitive super-predicates are converted.
|
|
fn super_predicates_of(tcx: TyCtxt<'_>, trait_def_id: DefId) -> ty::GenericPredicates<'_> {
|
|
debug!("super_predicates(trait_def_id={:?})", trait_def_id);
|
|
tcx.super_predicates_that_define_assoc_type((trait_def_id, None))
|
|
}
|
|
|
|
/// Ensures that the super-predicates of the trait with a `DefId`
|
|
/// of `trait_def_id` are converted and stored. This also ensures that
|
|
/// the transitive super-predicates are converted.
|
|
fn super_predicates_that_define_assoc_type(
|
|
tcx: TyCtxt<'_>,
|
|
(trait_def_id, assoc_name): (DefId, Option<Ident>),
|
|
) -> ty::GenericPredicates<'_> {
|
|
debug!(
|
|
"super_predicates_that_define_assoc_type(trait_def_id={:?}, assoc_name={:?})",
|
|
trait_def_id, assoc_name
|
|
);
|
|
if trait_def_id.is_local() {
|
|
debug!("super_predicates_that_define_assoc_type: local trait_def_id={:?}", trait_def_id);
|
|
let trait_hir_id = tcx.hir().local_def_id_to_hir_id(trait_def_id.expect_local());
|
|
|
|
let Node::Item(item) = tcx.hir().get(trait_hir_id) else {
|
|
bug!("trait_node_id {} is not an item", trait_hir_id);
|
|
};
|
|
|
|
let (generics, bounds) = match item.kind {
|
|
hir::ItemKind::Trait(.., ref generics, ref supertraits, _) => (generics, supertraits),
|
|
hir::ItemKind::TraitAlias(ref generics, ref supertraits) => (generics, supertraits),
|
|
_ => span_bug!(item.span, "super_predicates invoked on non-trait"),
|
|
};
|
|
|
|
let icx = ItemCtxt::new(tcx, trait_def_id);
|
|
|
|
// Convert the bounds that follow the colon, e.g., `Bar + Zed` in `trait Foo: Bar + Zed`.
|
|
let self_param_ty = tcx.types.self_param;
|
|
let superbounds1 = if let Some(assoc_name) = assoc_name {
|
|
<dyn AstConv<'_>>::compute_bounds_that_match_assoc_type(
|
|
&icx,
|
|
self_param_ty,
|
|
bounds,
|
|
assoc_name,
|
|
)
|
|
} else {
|
|
<dyn AstConv<'_>>::compute_bounds(&icx, self_param_ty, bounds)
|
|
};
|
|
|
|
let superbounds1 = superbounds1.predicates(tcx, self_param_ty);
|
|
|
|
// Convert any explicit superbounds in the where-clause,
|
|
// e.g., `trait Foo where Self: Bar`.
|
|
// In the case of trait aliases, however, we include all bounds in the where-clause,
|
|
// so e.g., `trait Foo = where u32: PartialEq<Self>` would include `u32: PartialEq<Self>`
|
|
// as one of its "superpredicates".
|
|
let is_trait_alias = tcx.is_trait_alias(trait_def_id);
|
|
let superbounds2 = icx.type_parameter_bounds_in_generics(
|
|
generics,
|
|
item.hir_id(),
|
|
self_param_ty,
|
|
OnlySelfBounds(!is_trait_alias),
|
|
assoc_name,
|
|
);
|
|
|
|
// Combine the two lists to form the complete set of superbounds:
|
|
let superbounds = &*tcx.arena.alloc_from_iter(superbounds1.into_iter().chain(superbounds2));
|
|
debug!(?superbounds);
|
|
|
|
// Now require that immediate supertraits are converted,
|
|
// which will, in turn, reach indirect supertraits.
|
|
if assoc_name.is_none() {
|
|
// Now require that immediate supertraits are converted,
|
|
// which will, in turn, reach indirect supertraits.
|
|
for &(pred, span) in superbounds {
|
|
debug!("superbound: {:?}", pred);
|
|
if let ty::PredicateKind::Trait(bound) = pred.kind().skip_binder() {
|
|
tcx.at(span).super_predicates_of(bound.def_id());
|
|
}
|
|
}
|
|
}
|
|
|
|
ty::GenericPredicates { parent: None, predicates: superbounds }
|
|
} else {
|
|
// if `assoc_name` is None, then the query should've been redirected to an
|
|
// external provider
|
|
assert!(assoc_name.is_some());
|
|
tcx.super_predicates_of(trait_def_id)
|
|
}
|
|
}
|
|
|
|
fn trait_def(tcx: TyCtxt<'_>, def_id: DefId) -> ty::TraitDef {
|
|
let item = tcx.hir().expect_item(def_id.expect_local());
|
|
|
|
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
|
|
.struct_span_err(
|
|
item.span,
|
|
"the `#[rustc_paren_sugar]` attribute is a temporary means of controlling \
|
|
which traits can use parenthetical notation",
|
|
)
|
|
.help("add `#![feature(unboxed_closures)]` to the crate attributes to use it")
|
|
.emit();
|
|
}
|
|
|
|
let is_marker = tcx.has_attr(def_id, sym::marker);
|
|
let skip_array_during_method_dispatch =
|
|
tcx.has_attr(def_id, sym::rustc_skip_array_during_method_dispatch);
|
|
let spec_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
|
|
.struct_span_err(
|
|
attr.span,
|
|
"the `#[rustc_must_implement_one_of]` attribute must be \
|
|
used with at least 2 args",
|
|
)
|
|
.emit();
|
|
|
|
None
|
|
}
|
|
Some(items) => items
|
|
.into_iter()
|
|
.map(|item| item.ident().ok_or(item.span()))
|
|
.collect::<Result<Box<[_]>, _>>()
|
|
.map_err(|span| {
|
|
tcx.sess
|
|
.struct_span_err(span, "must be a name of an associated function")
|
|
.emit();
|
|
})
|
|
.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.def_id).has_value() {
|
|
tcx.sess
|
|
.struct_span_err(
|
|
item.span,
|
|
"This function doesn't have a default implementation",
|
|
)
|
|
.span_note(attr_span, "required by this annotation")
|
|
.emit();
|
|
|
|
return Some(());
|
|
}
|
|
|
|
return None;
|
|
}
|
|
Some(item) => {
|
|
tcx.sess
|
|
.struct_span_err(item.span, "Not a function")
|
|
.span_note(attr_span, "required by this annotation")
|
|
.note(
|
|
"All `#[rustc_must_implement_one_of]` arguments \
|
|
must be associated function names",
|
|
)
|
|
.emit();
|
|
}
|
|
None => {
|
|
tcx.sess
|
|
.struct_span_err(ident.span, "Function not found in this trait")
|
|
.emit();
|
|
}
|
|
}
|
|
|
|
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
|
|
.struct_span_err(vec![dup, ident.span], "Functions names are duplicated")
|
|
.note(
|
|
"All `#[rustc_must_implement_one_of]` arguments \
|
|
must be unique",
|
|
)
|
|
.emit();
|
|
|
|
no_dups = false;
|
|
}
|
|
}
|
|
|
|
no_dups.then_some(list)
|
|
});
|
|
|
|
ty::TraitDef::new(
|
|
def_id,
|
|
unsafety,
|
|
paren_sugar,
|
|
is_auto,
|
|
is_marker,
|
|
skip_array_during_method_dispatch,
|
|
spec_kind,
|
|
must_implement_one_of,
|
|
)
|
|
}
|
|
|
|
fn has_late_bound_regions<'tcx>(tcx: TyCtxt<'tcx>, node: Node<'tcx>) -> Option<Span> {
|
|
struct LateBoundRegionsDetector<'tcx> {
|
|
tcx: TyCtxt<'tcx>,
|
|
outer_index: ty::DebruijnIndex,
|
|
has_late_bound_regions: Option<Span>,
|
|
}
|
|
|
|
impl<'tcx> Visitor<'tcx> for LateBoundRegionsDetector<'tcx> {
|
|
fn visit_ty(&mut self, ty: &'tcx hir::Ty<'tcx>) {
|
|
if self.has_late_bound_regions.is_some() {
|
|
return;
|
|
}
|
|
match ty.kind {
|
|
hir::TyKind::BareFn(..) => {
|
|
self.outer_index.shift_in(1);
|
|
intravisit::walk_ty(self, ty);
|
|
self.outer_index.shift_out(1);
|
|
}
|
|
_ => intravisit::walk_ty(self, ty),
|
|
}
|
|
}
|
|
|
|
fn visit_poly_trait_ref(&mut self, tr: &'tcx hir::PolyTraitRef<'tcx>) {
|
|
if self.has_late_bound_regions.is_some() {
|
|
return;
|
|
}
|
|
self.outer_index.shift_in(1);
|
|
intravisit::walk_poly_trait_ref(self, tr);
|
|
self.outer_index.shift_out(1);
|
|
}
|
|
|
|
fn visit_lifetime(&mut self, lt: &'tcx hir::Lifetime) {
|
|
if self.has_late_bound_regions.is_some() {
|
|
return;
|
|
}
|
|
|
|
match self.tcx.named_region(lt.hir_id) {
|
|
Some(rl::Region::Static | rl::Region::EarlyBound(..)) => {}
|
|
Some(rl::Region::LateBound(debruijn, _, _)) if debruijn < self.outer_index => {}
|
|
Some(rl::Region::LateBound(..) | rl::Region::Free(..)) | None => {
|
|
self.has_late_bound_regions = Some(lt.span);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
fn has_late_bound_regions<'tcx>(
|
|
tcx: TyCtxt<'tcx>,
|
|
generics: &'tcx hir::Generics<'tcx>,
|
|
decl: &'tcx hir::FnDecl<'tcx>,
|
|
) -> Option<Span> {
|
|
let mut visitor = LateBoundRegionsDetector {
|
|
tcx,
|
|
outer_index: ty::INNERMOST,
|
|
has_late_bound_regions: None,
|
|
};
|
|
for param in generics.params {
|
|
if let GenericParamKind::Lifetime { .. } = param.kind {
|
|
if tcx.is_late_bound(param.hir_id) {
|
|
return Some(param.span);
|
|
}
|
|
}
|
|
}
|
|
visitor.visit_fn_decl(decl);
|
|
visitor.has_late_bound_regions
|
|
}
|
|
|
|
match node {
|
|
Node::TraitItem(item) => match item.kind {
|
|
hir::TraitItemKind::Fn(ref sig, _) => {
|
|
has_late_bound_regions(tcx, &item.generics, sig.decl)
|
|
}
|
|
_ => None,
|
|
},
|
|
Node::ImplItem(item) => match item.kind {
|
|
hir::ImplItemKind::Fn(ref sig, _) => {
|
|
has_late_bound_regions(tcx, &item.generics, sig.decl)
|
|
}
|
|
_ => None,
|
|
},
|
|
Node::ForeignItem(item) => match item.kind {
|
|
hir::ForeignItemKind::Fn(fn_decl, _, ref generics) => {
|
|
has_late_bound_regions(tcx, generics, fn_decl)
|
|
}
|
|
_ => None,
|
|
},
|
|
Node::Item(item) => match item.kind {
|
|
hir::ItemKind::Fn(ref sig, .., ref generics, _) => {
|
|
has_late_bound_regions(tcx, generics, sig.decl)
|
|
}
|
|
_ => None,
|
|
},
|
|
_ => None,
|
|
}
|
|
}
|
|
|
|
struct AnonConstInParamTyDetector {
|
|
in_param_ty: bool,
|
|
found_anon_const_in_param_ty: bool,
|
|
ct: HirId,
|
|
}
|
|
|
|
impl<'v> Visitor<'v> for AnonConstInParamTyDetector {
|
|
fn visit_generic_param(&mut self, p: &'v hir::GenericParam<'v>) {
|
|
if let GenericParamKind::Const { ty, default: _ } = p.kind {
|
|
let prev = self.in_param_ty;
|
|
self.in_param_ty = true;
|
|
self.visit_ty(ty);
|
|
self.in_param_ty = prev;
|
|
}
|
|
}
|
|
|
|
fn visit_anon_const(&mut self, c: &'v hir::AnonConst) {
|
|
if self.in_param_ty && self.ct == c.hir_id {
|
|
self.found_anon_const_in_param_ty = true;
|
|
} else {
|
|
intravisit::walk_anon_const(self, c)
|
|
}
|
|
}
|
|
}
|
|
|
|
fn generics_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::Generics {
|
|
use rustc_hir::*;
|
|
|
|
let hir_id = tcx.hir().local_def_id_to_hir_id(def_id.expect_local());
|
|
|
|
let node = tcx.hir().get(hir_id);
|
|
let parent_def_id = match node {
|
|
Node::ImplItem(_)
|
|
| Node::TraitItem(_)
|
|
| Node::Variant(_)
|
|
| Node::Ctor(..)
|
|
| Node::Field(_) => {
|
|
let parent_id = tcx.hir().get_parent_item(hir_id);
|
|
Some(parent_id.to_def_id())
|
|
}
|
|
// FIXME(#43408) always enable this once `lazy_normalization` is
|
|
// stable enough and does not need a feature gate anymore.
|
|
Node::AnonConst(_) => {
|
|
let parent_def_id = tcx.hir().get_parent_item(hir_id);
|
|
|
|
let mut in_param_ty = false;
|
|
for (_parent, node) in tcx.hir().parent_iter(hir_id) {
|
|
if let Some(generics) = node.generics() {
|
|
let mut visitor = AnonConstInParamTyDetector {
|
|
in_param_ty: false,
|
|
found_anon_const_in_param_ty: false,
|
|
ct: hir_id,
|
|
};
|
|
|
|
visitor.visit_generics(generics);
|
|
in_param_ty = visitor.found_anon_const_in_param_ty;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if in_param_ty {
|
|
// We do not allow generic parameters in anon consts if we are inside
|
|
// of a const parameter type, e.g. `struct Foo<const N: usize, const M: [u8; N]>` is not allowed.
|
|
None
|
|
} else if tcx.lazy_normalization() {
|
|
if let Some(param_id) = tcx.hir().opt_const_param_default_param_hir_id(hir_id) {
|
|
// If the def_id we are calling generics_of on is an anon ct default i.e:
|
|
//
|
|
// struct Foo<const N: usize = { .. }>;
|
|
// ^^^ ^ ^^^^^^ def id of this anon const
|
|
// ^ ^ param_id
|
|
// ^ parent_def_id
|
|
//
|
|
// then we only want to return generics for params to the left of `N`. If we don't do that we
|
|
// end up with that const looking like: `ty::ConstKind::Unevaluated(def_id, substs: [N#0])`.
|
|
//
|
|
// This causes ICEs (#86580) when building the substs for Foo in `fn foo() -> Foo { .. }` as
|
|
// we substitute the defaults with the partially built substs when we build the substs. Subst'ing
|
|
// the `N#0` on the unevaluated const indexes into the empty substs we're in the process of building.
|
|
//
|
|
// We fix this by having this function return the parent's generics ourselves and truncating the
|
|
// generics to only include non-forward declared params (with the exception of the `Self` ty)
|
|
//
|
|
// For the above code example that means we want `substs: []`
|
|
// For the following struct def we want `substs: [N#0]` when generics_of is called on
|
|
// the def id of the `{ N + 1 }` anon const
|
|
// struct Foo<const N: usize, const M: usize = { N + 1 }>;
|
|
//
|
|
// This has some implications for how we get the predicates available to the anon const
|
|
// see `explicit_predicates_of` for more information on this
|
|
let generics = tcx.generics_of(parent_def_id.to_def_id());
|
|
let param_def = tcx.hir().local_def_id(param_id).to_def_id();
|
|
let param_def_idx = generics.param_def_id_to_index[¶m_def];
|
|
// In the above example this would be .params[..N#0]
|
|
let params = generics.params[..param_def_idx as usize].to_owned();
|
|
let param_def_id_to_index =
|
|
params.iter().map(|param| (param.def_id, param.index)).collect();
|
|
|
|
return ty::Generics {
|
|
// we set the parent of these generics to be our parent's parent so that we
|
|
// dont end up with substs: [N, M, N] for the const default on a struct like this:
|
|
// struct Foo<const N: usize, const M: usize = { ... }>;
|
|
parent: generics.parent,
|
|
parent_count: generics.parent_count,
|
|
params,
|
|
param_def_id_to_index,
|
|
has_self: generics.has_self,
|
|
has_late_bound_regions: generics.has_late_bound_regions,
|
|
};
|
|
}
|
|
|
|
// HACK(eddyb) this provides the correct generics when
|
|
// `feature(generic_const_expressions)` is enabled, so that const expressions
|
|
// used with const generics, e.g. `Foo<{N+1}>`, can work at all.
|
|
//
|
|
// Note that we do not supply the parent generics when using
|
|
// `min_const_generics`.
|
|
Some(parent_def_id.to_def_id())
|
|
} else {
|
|
let parent_node = tcx.hir().get(tcx.hir().get_parent_node(hir_id));
|
|
match parent_node {
|
|
// HACK(eddyb) this provides the correct generics for repeat
|
|
// expressions' count (i.e. `N` in `[x; N]`), and explicit
|
|
// `enum` discriminants (i.e. `D` in `enum Foo { Bar = D }`),
|
|
// as they shouldn't be able to cause query cycle errors.
|
|
Node::Expr(&Expr { kind: ExprKind::Repeat(_, ref constant), .. })
|
|
if constant.hir_id() == hir_id =>
|
|
{
|
|
Some(parent_def_id.to_def_id())
|
|
}
|
|
Node::Variant(Variant { disr_expr: Some(ref constant), .. })
|
|
if constant.hir_id == hir_id =>
|
|
{
|
|
Some(parent_def_id.to_def_id())
|
|
}
|
|
Node::Expr(&Expr { kind: ExprKind::ConstBlock(_), .. }) => {
|
|
Some(tcx.typeck_root_def_id(def_id))
|
|
}
|
|
// Exclude `GlobalAsm` here which cannot have generics.
|
|
Node::Expr(&Expr { kind: ExprKind::InlineAsm(asm), .. })
|
|
if asm.operands.iter().any(|(op, _op_sp)| match op {
|
|
hir::InlineAsmOperand::Const { anon_const }
|
|
| hir::InlineAsmOperand::SymFn { anon_const } => {
|
|
anon_const.hir_id == hir_id
|
|
}
|
|
_ => false,
|
|
}) =>
|
|
{
|
|
Some(parent_def_id.to_def_id())
|
|
}
|
|
_ => None,
|
|
}
|
|
}
|
|
}
|
|
Node::Expr(&hir::Expr { kind: hir::ExprKind::Closure { .. }, .. }) => {
|
|
Some(tcx.typeck_root_def_id(def_id))
|
|
}
|
|
Node::Item(item) => match item.kind {
|
|
ItemKind::OpaqueTy(hir::OpaqueTy {
|
|
origin:
|
|
hir::OpaqueTyOrigin::FnReturn(fn_def_id) | hir::OpaqueTyOrigin::AsyncFn(fn_def_id),
|
|
in_trait,
|
|
..
|
|
}) => {
|
|
if in_trait {
|
|
assert!(matches!(tcx.def_kind(fn_def_id), DefKind::AssocFn))
|
|
} else {
|
|
assert!(matches!(tcx.def_kind(fn_def_id), DefKind::AssocFn | DefKind::Fn))
|
|
}
|
|
Some(fn_def_id.to_def_id())
|
|
}
|
|
ItemKind::OpaqueTy(hir::OpaqueTy { origin: hir::OpaqueTyOrigin::TyAlias, .. }) => {
|
|
let parent_id = tcx.hir().get_parent_item(hir_id);
|
|
assert_ne!(parent_id, hir::CRATE_OWNER_ID);
|
|
debug!("generics_of: parent of opaque ty {:?} is {:?}", def_id, parent_id);
|
|
// Opaque types are always nested within another item, and
|
|
// inherit the generics of the item.
|
|
Some(parent_id.to_def_id())
|
|
}
|
|
_ => None,
|
|
},
|
|
_ => None,
|
|
};
|
|
|
|
enum Defaults {
|
|
Allowed,
|
|
// See #36887
|
|
FutureCompatDisallowed,
|
|
Deny,
|
|
}
|
|
|
|
let no_generics = hir::Generics::empty();
|
|
let ast_generics = node.generics().unwrap_or(&no_generics);
|
|
let (opt_self, allow_defaults) = match node {
|
|
Node::Item(item) => {
|
|
match item.kind {
|
|
ItemKind::Trait(..) | ItemKind::TraitAlias(..) => {
|
|
// Add in the self type parameter.
|
|
//
|
|
// Something of a hack: use the node id for the trait, also as
|
|
// the node id for the Self type parameter.
|
|
let opt_self = Some(ty::GenericParamDef {
|
|
index: 0,
|
|
name: kw::SelfUpper,
|
|
def_id,
|
|
pure_wrt_drop: false,
|
|
kind: ty::GenericParamDefKind::Type {
|
|
has_default: false,
|
|
synthetic: false,
|
|
},
|
|
});
|
|
|
|
(opt_self, Defaults::Allowed)
|
|
}
|
|
ItemKind::TyAlias(..)
|
|
| ItemKind::Enum(..)
|
|
| ItemKind::Struct(..)
|
|
| ItemKind::OpaqueTy(..)
|
|
| ItemKind::Union(..) => (None, Defaults::Allowed),
|
|
_ => (None, Defaults::FutureCompatDisallowed),
|
|
}
|
|
}
|
|
|
|
// GATs
|
|
Node::TraitItem(item) if matches!(item.kind, TraitItemKind::Type(..)) => {
|
|
(None, Defaults::Deny)
|
|
}
|
|
Node::ImplItem(item) if matches!(item.kind, ImplItemKind::TyAlias(..)) => {
|
|
(None, Defaults::Deny)
|
|
}
|
|
|
|
_ => (None, Defaults::FutureCompatDisallowed),
|
|
};
|
|
|
|
let has_self = opt_self.is_some();
|
|
let mut parent_has_self = false;
|
|
let mut own_start = has_self as u32;
|
|
let parent_count = parent_def_id.map_or(0, |def_id| {
|
|
let generics = tcx.generics_of(def_id);
|
|
assert!(!has_self);
|
|
parent_has_self = generics.has_self;
|
|
own_start = generics.count() as u32;
|
|
generics.parent_count + generics.params.len()
|
|
});
|
|
|
|
let mut params: Vec<_> = Vec::with_capacity(ast_generics.params.len() + has_self as usize);
|
|
|
|
if let Some(opt_self) = opt_self {
|
|
params.push(opt_self);
|
|
}
|
|
|
|
let early_lifetimes = early_bound_lifetimes_from_generics(tcx, ast_generics);
|
|
params.extend(early_lifetimes.enumerate().map(|(i, param)| ty::GenericParamDef {
|
|
name: param.name.ident().name,
|
|
index: own_start + i as u32,
|
|
def_id: tcx.hir().local_def_id(param.hir_id).to_def_id(),
|
|
pure_wrt_drop: param.pure_wrt_drop,
|
|
kind: ty::GenericParamDefKind::Lifetime,
|
|
}));
|
|
|
|
// Now create the real type and const parameters.
|
|
let type_start = own_start - has_self as u32 + params.len() as u32;
|
|
let mut i = 0;
|
|
|
|
const TYPE_DEFAULT_NOT_ALLOWED: &'static str = "defaults for type parameters are only allowed in \
|
|
`struct`, `enum`, `type`, or `trait` definitions";
|
|
|
|
params.extend(ast_generics.params.iter().filter_map(|param| match param.kind {
|
|
GenericParamKind::Lifetime { .. } => None,
|
|
GenericParamKind::Type { ref default, synthetic, .. } => {
|
|
if default.is_some() {
|
|
match allow_defaults {
|
|
Defaults::Allowed => {}
|
|
Defaults::FutureCompatDisallowed
|
|
if tcx.features().default_type_parameter_fallback => {}
|
|
Defaults::FutureCompatDisallowed => {
|
|
tcx.struct_span_lint_hir(
|
|
lint::builtin::INVALID_TYPE_PARAM_DEFAULT,
|
|
param.hir_id,
|
|
param.span,
|
|
|lint| {
|
|
lint.build(TYPE_DEFAULT_NOT_ALLOWED).emit();
|
|
},
|
|
);
|
|
}
|
|
Defaults::Deny => {
|
|
tcx.sess.span_err(param.span, TYPE_DEFAULT_NOT_ALLOWED);
|
|
}
|
|
}
|
|
}
|
|
|
|
let kind = ty::GenericParamDefKind::Type { has_default: default.is_some(), synthetic };
|
|
|
|
let param_def = ty::GenericParamDef {
|
|
index: type_start + i as u32,
|
|
name: param.name.ident().name,
|
|
def_id: tcx.hir().local_def_id(param.hir_id).to_def_id(),
|
|
pure_wrt_drop: param.pure_wrt_drop,
|
|
kind,
|
|
};
|
|
i += 1;
|
|
Some(param_def)
|
|
}
|
|
GenericParamKind::Const { default, .. } => {
|
|
if !matches!(allow_defaults, Defaults::Allowed) && default.is_some() {
|
|
tcx.sess.span_err(
|
|
param.span,
|
|
"defaults for const parameters are only allowed in \
|
|
`struct`, `enum`, `type`, or `trait` definitions",
|
|
);
|
|
}
|
|
|
|
let param_def = ty::GenericParamDef {
|
|
index: type_start + i as u32,
|
|
name: param.name.ident().name,
|
|
def_id: tcx.hir().local_def_id(param.hir_id).to_def_id(),
|
|
pure_wrt_drop: param.pure_wrt_drop,
|
|
kind: ty::GenericParamDefKind::Const { has_default: default.is_some() },
|
|
};
|
|
i += 1;
|
|
Some(param_def)
|
|
}
|
|
}));
|
|
|
|
// provide junk type parameter defs - the only place that
|
|
// cares about anything but the length is instantiation,
|
|
// and we don't do that for closures.
|
|
if let Node::Expr(&hir::Expr {
|
|
kind: hir::ExprKind::Closure(hir::Closure { movability: gen, .. }),
|
|
..
|
|
}) = node
|
|
{
|
|
let dummy_args = if gen.is_some() {
|
|
&["<resume_ty>", "<yield_ty>", "<return_ty>", "<witness>", "<upvars>"][..]
|
|
} else {
|
|
&["<closure_kind>", "<closure_signature>", "<upvars>"][..]
|
|
};
|
|
|
|
params.extend(dummy_args.iter().enumerate().map(|(i, &arg)| ty::GenericParamDef {
|
|
index: type_start + i as u32,
|
|
name: Symbol::intern(arg),
|
|
def_id,
|
|
pure_wrt_drop: false,
|
|
kind: ty::GenericParamDefKind::Type { has_default: false, synthetic: false },
|
|
}));
|
|
}
|
|
|
|
// provide junk type parameter defs for const blocks.
|
|
if let Node::AnonConst(_) = node {
|
|
let parent_node = tcx.hir().get(tcx.hir().get_parent_node(hir_id));
|
|
if let Node::Expr(&Expr { kind: ExprKind::ConstBlock(_), .. }) = parent_node {
|
|
params.push(ty::GenericParamDef {
|
|
index: type_start,
|
|
name: Symbol::intern("<const_ty>"),
|
|
def_id,
|
|
pure_wrt_drop: false,
|
|
kind: ty::GenericParamDefKind::Type { has_default: false, synthetic: false },
|
|
});
|
|
}
|
|
}
|
|
|
|
let param_def_id_to_index = params.iter().map(|param| (param.def_id, param.index)).collect();
|
|
|
|
ty::Generics {
|
|
parent: parent_def_id,
|
|
parent_count,
|
|
params,
|
|
param_def_id_to_index,
|
|
has_self: has_self || parent_has_self,
|
|
has_late_bound_regions: has_late_bound_regions(tcx, node),
|
|
}
|
|
}
|
|
|
|
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) | Rptr(_, 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: DefId) -> ty::PolyFnSig<'_> {
|
|
use rustc_hir::Node::*;
|
|
use rustc_hir::*;
|
|
|
|
let def_id = def_id.expect_local();
|
|
let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
|
|
|
|
let icx = ItemCtxt::new(tcx, def_id.to_def_id());
|
|
|
|
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 inference the return type for a impl method coming from a trait
|
|
if let Item(hir::Item { kind: ItemKind::Impl(i), .. }) =
|
|
tcx.hir().get(tcx.hir().get_parent_node(hir_id))
|
|
&& i.of_trait.is_some()
|
|
{
|
|
<dyn AstConv<'_>>::ty_of_fn(
|
|
&icx,
|
|
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,
|
|
..
|
|
}) => <dyn AstConv<'_>>::ty_of_fn(
|
|
&icx,
|
|
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.to_def_id(), fn_decl, abi)
|
|
}
|
|
|
|
Ctor(data) | Variant(hir::Variant { data, .. }) if data.ctor_hir_id().is_some() => {
|
|
let ty = tcx.type_of(tcx.hir().get_parent_item(hir_id));
|
|
let inputs =
|
|
data.fields().iter().map(|f| tcx.type_of(tcx.hir().local_def_id(f.hir_id)));
|
|
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);
|
|
}
|
|
}
|
|
}
|
|
|
|
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 fn_sig = ty::Binder::dummy(fn_sig);
|
|
|
|
let mut visitor = HirPlaceholderCollector::default();
|
|
visitor.visit_ty(ty);
|
|
let mut diag = bad_placeholder(tcx, visitor.0, "return type");
|
|
let ret_ty = fn_sig.skip_binder().output();
|
|
if ret_ty.is_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 fn_sig = ret_ty.fn_sig(tcx);
|
|
if fn_sig
|
|
.skip_binder()
|
|
.inputs_and_output
|
|
.iter()
|
|
.all(|t| t.is_suggestable(tcx, false))
|
|
{
|
|
diag.span_suggestion(
|
|
ty.span,
|
|
"replace with the correct return type",
|
|
fn_sig,
|
|
Applicability::MachineApplicable,
|
|
);
|
|
}
|
|
} else if ret_ty.is_closure() {
|
|
// We're dealing with a closure, so we should suggest using `impl Fn` or trait bounds
|
|
// to prevent the user from getting a papercut while trying to use the unique closure
|
|
// syntax (e.g. `[closure@src/lib.rs:2:5: 2:9]`).
|
|
diag.help("consider using an `Fn`, `FnMut`, or `FnOnce` trait bound");
|
|
diag.note("for more information on `Fn` traits and closure types, see https://doc.rust-lang.org/book/ch13-01-closures.html");
|
|
}
|
|
diag.emit();
|
|
|
|
fn_sig
|
|
}
|
|
None => <dyn AstConv<'_>>::ty_of_fn(
|
|
icx,
|
|
hir_id,
|
|
sig.header.unsafety,
|
|
sig.header.abi,
|
|
sig.decl,
|
|
Some(generics),
|
|
None,
|
|
),
|
|
}
|
|
}
|
|
|
|
fn impl_trait_ref(tcx: TyCtxt<'_>, def_id: DefId) -> Option<ty::TraitRef<'_>> {
|
|
let icx = ItemCtxt::new(tcx, def_id);
|
|
match tcx.hir().expect_item(def_id.expect_local()).kind {
|
|
hir::ItemKind::Impl(ref impl_) => impl_.of_trait.as_ref().map(|ast_trait_ref| {
|
|
let selfty = tcx.type_of(def_id);
|
|
<dyn AstConv<'_>>::instantiate_mono_trait_ref(&icx, ast_trait_ref, selfty)
|
|
}),
|
|
_ => bug!(),
|
|
}
|
|
}
|
|
|
|
fn impl_polarity(tcx: TyCtxt<'_>, def_id: DefId) -> ty::ImplPolarity {
|
|
let is_rustc_reservation = tcx.has_attr(def_id, sym::rustc_reservation_impl);
|
|
let item = tcx.hir().expect_item(def_id.expect_local());
|
|
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,
|
|
);
|
|
if result.predicates.is_empty() {
|
|
result.predicates = inferred_outlives;
|
|
} else {
|
|
result.predicates = tcx
|
|
.arena
|
|
.alloc_from_iter(result.predicates.iter().chain(inferred_outlives).copied());
|
|
}
|
|
}
|
|
|
|
debug!("predicates_defined_on({:?}) = {:?}", def_id, result);
|
|
result
|
|
}
|
|
|
|
/// Returns a list of all type predicates (explicit and implicit) for the definition with
|
|
/// ID `def_id`. This includes all predicates returned by `predicates_defined_on`, plus
|
|
/// `Self: Trait` predicates for traits.
|
|
fn predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericPredicates<'_> {
|
|
let mut result = tcx.predicates_defined_on(def_id);
|
|
|
|
if tcx.is_trait(def_id) {
|
|
// For traits, add `Self: Trait` predicate. This is
|
|
// not part of the predicates that a user writes, but it
|
|
// is something that one must prove in order to invoke a
|
|
// method or project an associated type.
|
|
//
|
|
// In the chalk setup, this predicate is not part of the
|
|
// "predicates" for a trait item. But it is useful in
|
|
// rustc because if you directly (e.g.) invoke a trait
|
|
// method like `Trait::method(...)`, you must naturally
|
|
// prove that the trait applies to the types that were
|
|
// used, and adding the predicate into this list ensures
|
|
// that this is done.
|
|
//
|
|
// We use a DUMMY_SP here as a way to signal trait bounds that come
|
|
// from the trait itself that *shouldn't* be shown as the source of
|
|
// an obligation and instead be skipped. Otherwise we'd use
|
|
// `tcx.def_span(def_id);`
|
|
|
|
let constness = if tcx.has_attr(def_id, sym::const_trait) {
|
|
ty::BoundConstness::ConstIfConst
|
|
} else {
|
|
ty::BoundConstness::NotConst
|
|
};
|
|
|
|
let span = rustc_span::DUMMY_SP;
|
|
result.predicates =
|
|
tcx.arena.alloc_from_iter(result.predicates.iter().copied().chain(std::iter::once((
|
|
ty::TraitRef::identity(tcx, def_id).with_constness(constness).to_predicate(tcx),
|
|
span,
|
|
))));
|
|
}
|
|
debug!("predicates_of(def_id={:?}) = {:?}", def_id, result);
|
|
result
|
|
}
|
|
|
|
/// Returns a list of user-specified type predicates for the definition with ID `def_id`.
|
|
/// N.B., this does not include any implied/inferred constraints.
|
|
#[instrument(level = "trace", skip(tcx), ret)]
|
|
fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericPredicates<'_> {
|
|
use rustc_hir::*;
|
|
|
|
let hir_id = tcx.hir().local_def_id_to_hir_id(def_id.expect_local());
|
|
let node = tcx.hir().get(hir_id);
|
|
|
|
let mut is_trait = None;
|
|
let mut is_default_impl_trait = None;
|
|
|
|
let icx = ItemCtxt::new(tcx, def_id);
|
|
|
|
const NO_GENERICS: &hir::Generics<'_> = hir::Generics::empty();
|
|
|
|
// We use an `IndexSet` to preserves order of insertion.
|
|
// Preserving the order of insertion is important here so as not to break UI tests.
|
|
let mut predicates: FxIndexSet<(ty::Predicate<'_>, Span)> = FxIndexSet::default();
|
|
|
|
let ast_generics = match node {
|
|
Node::TraitItem(item) => item.generics,
|
|
|
|
Node::ImplItem(item) => item.generics,
|
|
|
|
Node::Item(item) => {
|
|
match item.kind {
|
|
ItemKind::Impl(ref impl_) => {
|
|
if impl_.defaultness.is_default() {
|
|
is_default_impl_trait = tcx.impl_trait_ref(def_id).map(ty::Binder::dummy);
|
|
}
|
|
&impl_.generics
|
|
}
|
|
ItemKind::Fn(.., ref generics, _)
|
|
| ItemKind::TyAlias(_, ref generics)
|
|
| ItemKind::Enum(_, ref generics)
|
|
| ItemKind::Struct(_, ref generics)
|
|
| ItemKind::Union(_, ref generics) => *generics,
|
|
|
|
ItemKind::Trait(_, _, ref generics, ..) => {
|
|
is_trait = Some(ty::TraitRef::identity(tcx, def_id));
|
|
*generics
|
|
}
|
|
ItemKind::TraitAlias(ref generics, _) => {
|
|
is_trait = Some(ty::TraitRef::identity(tcx, def_id));
|
|
*generics
|
|
}
|
|
ItemKind::OpaqueTy(OpaqueTy {
|
|
origin: hir::OpaqueTyOrigin::AsyncFn(..) | hir::OpaqueTyOrigin::FnReturn(..),
|
|
..
|
|
}) => {
|
|
// return-position impl trait
|
|
//
|
|
// We don't inherit predicates from the parent here:
|
|
// If we have, say `fn f<'a, T: 'a>() -> impl Sized {}`
|
|
// then the return type is `f::<'static, T>::{{opaque}}`.
|
|
//
|
|
// If we inherited the predicates of `f` then we would
|
|
// require that `T: 'static` to show that the return
|
|
// type is well-formed.
|
|
//
|
|
// The only way to have something with this opaque type
|
|
// is from the return type of the containing function,
|
|
// which will ensure that the function's predicates
|
|
// hold.
|
|
return ty::GenericPredicates { parent: None, predicates: &[] };
|
|
}
|
|
ItemKind::OpaqueTy(OpaqueTy {
|
|
ref generics,
|
|
origin: hir::OpaqueTyOrigin::TyAlias,
|
|
..
|
|
}) => {
|
|
// type-alias impl trait
|
|
generics
|
|
}
|
|
|
|
_ => NO_GENERICS,
|
|
}
|
|
}
|
|
|
|
Node::ForeignItem(item) => match item.kind {
|
|
ForeignItemKind::Static(..) => NO_GENERICS,
|
|
ForeignItemKind::Fn(_, _, ref generics) => *generics,
|
|
ForeignItemKind::Type => NO_GENERICS,
|
|
},
|
|
|
|
_ => NO_GENERICS,
|
|
};
|
|
|
|
let generics = tcx.generics_of(def_id);
|
|
let parent_count = generics.parent_count as u32;
|
|
let has_own_self = generics.has_self && parent_count == 0;
|
|
|
|
// Below we'll consider the bounds on the type parameters (including `Self`)
|
|
// and the explicit where-clauses, but to get the full set of predicates
|
|
// on a trait we need to add in the supertrait bounds and bounds found on
|
|
// associated types.
|
|
if let Some(_trait_ref) = is_trait {
|
|
predicates.extend(tcx.super_predicates_of(def_id).predicates.iter().cloned());
|
|
}
|
|
|
|
// In default impls, we can assume that the self type implements
|
|
// the trait. So in:
|
|
//
|
|
// default impl Foo for Bar { .. }
|
|
//
|
|
// we add a default where clause `Foo: Bar`. We do a similar thing for traits
|
|
// (see below). Recall that a default impl is not itself an impl, but rather a
|
|
// set of defaults that can be incorporated into another impl.
|
|
if let Some(trait_ref) = is_default_impl_trait {
|
|
predicates.insert((trait_ref.without_const().to_predicate(tcx), tcx.def_span(def_id)));
|
|
}
|
|
|
|
// Collect the region predicates that were declared inline as
|
|
// well. In the case of parameters declared on a fn or method, we
|
|
// have to be careful to only iterate over early-bound regions.
|
|
let mut index = parent_count
|
|
+ has_own_self as u32
|
|
+ early_bound_lifetimes_from_generics(tcx, ast_generics).count() as u32;
|
|
|
|
trace!(?predicates);
|
|
trace!(?ast_generics);
|
|
|
|
// Collect the predicates that were written inline by the user on each
|
|
// type parameter (e.g., `<T: Foo>`).
|
|
for param in ast_generics.params {
|
|
match param.kind {
|
|
// We already dealt with early bound lifetimes above.
|
|
GenericParamKind::Lifetime { .. } => (),
|
|
GenericParamKind::Type { .. } => {
|
|
let name = param.name.ident().name;
|
|
let param_ty = ty::ParamTy::new(index, name).to_ty(tcx);
|
|
index += 1;
|
|
|
|
let mut bounds = Bounds::default();
|
|
// Params are implicitly sized unless a `?Sized` bound is found
|
|
<dyn AstConv<'_>>::add_implicitly_sized(
|
|
&icx,
|
|
&mut bounds,
|
|
&[],
|
|
Some((param.hir_id, ast_generics.predicates)),
|
|
param.span,
|
|
);
|
|
trace!(?bounds);
|
|
predicates.extend(bounds.predicates(tcx, param_ty));
|
|
trace!(?predicates);
|
|
}
|
|
GenericParamKind::Const { .. } => {
|
|
// Bounds on const parameters are currently not possible.
|
|
index += 1;
|
|
}
|
|
}
|
|
}
|
|
|
|
trace!(?predicates);
|
|
// Add in the bounds that appear in the where-clause.
|
|
for predicate in ast_generics.predicates {
|
|
match predicate {
|
|
hir::WherePredicate::BoundPredicate(bound_pred) => {
|
|
let ty = icx.to_ty(bound_pred.bounded_ty);
|
|
let bound_vars = icx.tcx.late_bound_vars(bound_pred.bounded_ty.hir_id);
|
|
|
|
// Keep the type around in a dummy predicate, in case of no bounds.
|
|
// That way, `where Ty:` is not a complete noop (see #53696) and `Ty`
|
|
// is still checked for WF.
|
|
if bound_pred.bounds.is_empty() {
|
|
if let ty::Param(_) = ty.kind() {
|
|
// This is a `where T:`, which can be in the HIR from the
|
|
// transformation that moves `?Sized` to `T`'s declaration.
|
|
// We can skip the predicate because type parameters are
|
|
// trivially WF, but also we *should*, to avoid exposing
|
|
// users who never wrote `where Type:,` themselves, to
|
|
// compiler/tooling bugs from not handling WF predicates.
|
|
} else {
|
|
let span = bound_pred.bounded_ty.span;
|
|
let predicate = ty::Binder::bind_with_vars(
|
|
ty::PredicateKind::WellFormed(ty.into()),
|
|
bound_vars,
|
|
);
|
|
predicates.insert((predicate.to_predicate(tcx), span));
|
|
}
|
|
}
|
|
|
|
let mut bounds = Bounds::default();
|
|
<dyn AstConv<'_>>::add_bounds(
|
|
&icx,
|
|
ty,
|
|
bound_pred.bounds.iter(),
|
|
&mut bounds,
|
|
bound_vars,
|
|
);
|
|
predicates.extend(bounds.predicates(tcx, ty));
|
|
}
|
|
|
|
hir::WherePredicate::RegionPredicate(region_pred) => {
|
|
let r1 = <dyn AstConv<'_>>::ast_region_to_region(&icx, ®ion_pred.lifetime, None);
|
|
predicates.extend(region_pred.bounds.iter().map(|bound| {
|
|
let (r2, span) = match bound {
|
|
hir::GenericBound::Outlives(lt) => {
|
|
(<dyn AstConv<'_>>::ast_region_to_region(&icx, lt, None), lt.span)
|
|
}
|
|
_ => bug!(),
|
|
};
|
|
let pred = ty::Binder::dummy(ty::PredicateKind::RegionOutlives(
|
|
ty::OutlivesPredicate(r1, r2),
|
|
))
|
|
.to_predicate(icx.tcx);
|
|
|
|
(pred, span)
|
|
}))
|
|
}
|
|
|
|
hir::WherePredicate::EqPredicate(..) => {
|
|
// FIXME(#20041)
|
|
}
|
|
}
|
|
}
|
|
|
|
if tcx.features().generic_const_exprs {
|
|
predicates.extend(const_evaluatable_predicates_of(tcx, def_id.expect_local()));
|
|
}
|
|
|
|
let mut predicates: Vec<_> = predicates.into_iter().collect();
|
|
|
|
// Subtle: before we store the predicates into the tcx, we
|
|
// sort them so that predicates like `T: Foo<Item=U>` come
|
|
// before uses of `U`. This avoids false ambiguity errors
|
|
// in trait checking. See `setup_constraining_predicates`
|
|
// for details.
|
|
if let Node::Item(&Item { kind: ItemKind::Impl { .. }, .. }) = node {
|
|
let self_ty = tcx.type_of(def_id);
|
|
let trait_ref = tcx.impl_trait_ref(def_id);
|
|
cgp::setup_constraining_predicates(
|
|
tcx,
|
|
&mut predicates,
|
|
trait_ref,
|
|
&mut cgp::parameters_for_impl(self_ty, trait_ref),
|
|
);
|
|
}
|
|
|
|
ty::GenericPredicates {
|
|
parent: generics.parent,
|
|
predicates: tcx.arena.alloc_from_iter(predicates),
|
|
}
|
|
}
|
|
|
|
fn const_evaluatable_predicates_of<'tcx>(
|
|
tcx: TyCtxt<'tcx>,
|
|
def_id: LocalDefId,
|
|
) -> FxIndexSet<(ty::Predicate<'tcx>, Span)> {
|
|
struct ConstCollector<'tcx> {
|
|
tcx: TyCtxt<'tcx>,
|
|
preds: FxIndexSet<(ty::Predicate<'tcx>, Span)>,
|
|
}
|
|
|
|
impl<'tcx> intravisit::Visitor<'tcx> for ConstCollector<'tcx> {
|
|
fn visit_anon_const(&mut self, c: &'tcx hir::AnonConst) {
|
|
let def_id = self.tcx.hir().local_def_id(c.hir_id);
|
|
let ct = ty::Const::from_anon_const(self.tcx, def_id);
|
|
if let ty::ConstKind::Unevaluated(uv) = ct.kind() {
|
|
let span = self.tcx.hir().span(c.hir_id);
|
|
self.preds.insert((
|
|
ty::Binder::dummy(ty::PredicateKind::ConstEvaluatable(uv))
|
|
.to_predicate(self.tcx),
|
|
span,
|
|
));
|
|
}
|
|
}
|
|
|
|
fn visit_const_param_default(&mut self, _param: HirId, _ct: &'tcx hir::AnonConst) {
|
|
// Do not look into const param defaults,
|
|
// these get checked when they are actually instantiated.
|
|
//
|
|
// We do not want the following to error:
|
|
//
|
|
// struct Foo<const N: usize, const M: usize = { N + 1 }>;
|
|
// struct Bar<const N: usize>(Foo<N, 3>);
|
|
}
|
|
}
|
|
|
|
let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
|
|
let node = tcx.hir().get(hir_id);
|
|
|
|
let mut collector = ConstCollector { tcx, preds: FxIndexSet::default() };
|
|
if let hir::Node::Item(item) = node && let hir::ItemKind::Impl(ref impl_) = item.kind {
|
|
if let Some(of_trait) = &impl_.of_trait {
|
|
debug!("const_evaluatable_predicates_of({:?}): visit impl trait_ref", def_id);
|
|
collector.visit_trait_ref(of_trait);
|
|
}
|
|
|
|
debug!("const_evaluatable_predicates_of({:?}): visit_self_ty", def_id);
|
|
collector.visit_ty(impl_.self_ty);
|
|
}
|
|
|
|
if let Some(generics) = node.generics() {
|
|
debug!("const_evaluatable_predicates_of({:?}): visit_generics", def_id);
|
|
collector.visit_generics(generics);
|
|
}
|
|
|
|
if let Some(fn_sig) = tcx.hir().fn_sig_by_hir_id(hir_id) {
|
|
debug!("const_evaluatable_predicates_of({:?}): visit_fn_decl", def_id);
|
|
collector.visit_fn_decl(fn_sig.decl);
|
|
}
|
|
debug!("const_evaluatable_predicates_of({:?}) = {:?}", def_id, collector.preds);
|
|
|
|
collector.preds
|
|
}
|
|
|
|
fn trait_explicit_predicates_and_bounds(
|
|
tcx: TyCtxt<'_>,
|
|
def_id: LocalDefId,
|
|
) -> ty::GenericPredicates<'_> {
|
|
assert_eq!(tcx.def_kind(def_id), DefKind::Trait);
|
|
gather_explicit_predicates_of(tcx, def_id.to_def_id())
|
|
}
|
|
|
|
fn explicit_predicates_of<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> ty::GenericPredicates<'tcx> {
|
|
let def_kind = tcx.def_kind(def_id);
|
|
if let DefKind::Trait = def_kind {
|
|
// Remove bounds on associated types from the predicates, they will be
|
|
// returned by `explicit_item_bounds`.
|
|
let predicates_and_bounds = tcx.trait_explicit_predicates_and_bounds(def_id.expect_local());
|
|
let trait_identity_substs = InternalSubsts::identity_for_item(tcx, def_id);
|
|
|
|
let is_assoc_item_ty = |ty: Ty<'tcx>| {
|
|
// For a predicate from a where clause to become a bound on an
|
|
// associated type:
|
|
// * It must use the identity substs of the item.
|
|
// * Since any generic parameters on the item are not in scope,
|
|
// this means that the item is not a GAT, and its identity
|
|
// substs are the same as the trait's.
|
|
// * It must be an associated type for this trait (*not* a
|
|
// supertrait).
|
|
if let ty::Projection(projection) = ty.kind() {
|
|
projection.substs == trait_identity_substs
|
|
&& tcx.associated_item(projection.item_def_id).container_id(tcx) == def_id
|
|
} else {
|
|
false
|
|
}
|
|
};
|
|
|
|
let predicates: Vec<_> = predicates_and_bounds
|
|
.predicates
|
|
.iter()
|
|
.copied()
|
|
.filter(|(pred, _)| match pred.kind().skip_binder() {
|
|
ty::PredicateKind::Trait(tr) => !is_assoc_item_ty(tr.self_ty()),
|
|
ty::PredicateKind::Projection(proj) => {
|
|
!is_assoc_item_ty(proj.projection_ty.self_ty())
|
|
}
|
|
ty::PredicateKind::TypeOutlives(outlives) => !is_assoc_item_ty(outlives.0),
|
|
_ => true,
|
|
})
|
|
.collect();
|
|
if predicates.len() == predicates_and_bounds.predicates.len() {
|
|
predicates_and_bounds
|
|
} else {
|
|
ty::GenericPredicates {
|
|
parent: predicates_and_bounds.parent,
|
|
predicates: tcx.arena.alloc_slice(&predicates),
|
|
}
|
|
}
|
|
} else {
|
|
if matches!(def_kind, DefKind::AnonConst) && tcx.lazy_normalization() {
|
|
let hir_id = tcx.hir().local_def_id_to_hir_id(def_id.expect_local());
|
|
if tcx.hir().opt_const_param_default_param_hir_id(hir_id).is_some() {
|
|
// In `generics_of` we set the generics' parent to be our parent's parent which means that
|
|
// we lose out on the predicates of our actual parent if we dont return those predicates here.
|
|
// (See comment in `generics_of` for more information on why the parent shenanigans is necessary)
|
|
//
|
|
// struct Foo<T, const N: usize = { <T as Trait>::ASSOC }>(T) where T: Trait;
|
|
// ^^^ ^^^^^^^^^^^^^^^^^^^^^^^ the def id we are calling
|
|
// ^^^ explicit_predicates_of on
|
|
// parent item we dont have set as the
|
|
// parent of generics returned by `generics_of`
|
|
//
|
|
// In the above code we want the anon const to have predicates in its param env for `T: Trait`
|
|
let item_def_id = tcx.hir().get_parent_item(hir_id);
|
|
// In the above code example we would be calling `explicit_predicates_of(Foo)` here
|
|
return tcx.explicit_predicates_of(item_def_id);
|
|
}
|
|
}
|
|
gather_explicit_predicates_of(tcx, def_id)
|
|
}
|
|
}
|
|
|
|
/// Converts a specific `GenericBound` from the AST into a set of
|
|
/// predicates that apply to the self type. A vector is returned
|
|
/// because this can be anywhere from zero predicates (`T: ?Sized` adds no
|
|
/// predicates) to one (`T: Foo`) to many (`T: Bar<X = i32>` adds `T: Bar`
|
|
/// and `<T as Bar>::X == i32`).
|
|
fn predicates_from_bound<'tcx>(
|
|
astconv: &dyn AstConv<'tcx>,
|
|
param_ty: Ty<'tcx>,
|
|
bound: &'tcx hir::GenericBound<'tcx>,
|
|
bound_vars: &'tcx ty::List<ty::BoundVariableKind>,
|
|
) -> Vec<(ty::Predicate<'tcx>, Span)> {
|
|
let mut bounds = Bounds::default();
|
|
astconv.add_bounds(param_ty, [bound].into_iter(), &mut bounds, bound_vars);
|
|
bounds.predicates(astconv.tcx(), param_ty).collect()
|
|
}
|
|
|
|
fn compute_sig_of_foreign_fn_decl<'tcx>(
|
|
tcx: TyCtxt<'tcx>,
|
|
def_id: DefId,
|
|
decl: &'tcx hir::FnDecl<'tcx>,
|
|
abi: abi::Abi,
|
|
) -> ty::PolyFnSig<'tcx> {
|
|
let unsafety = if abi == abi::Abi::RustIntrinsic {
|
|
intrinsic_operation_unsafety(tcx.item_name(def_id))
|
|
} else {
|
|
hir::Unsafety::Unsafe
|
|
};
|
|
let hir_id = tcx.hir().local_def_id_to_hir_id(def_id.expect_local());
|
|
let fty = <dyn AstConv<'_>>::ty_of_fn(
|
|
&ItemCtxt::new(tcx, def_id),
|
|
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
|
|
.struct_span_err(
|
|
ast_ty.span,
|
|
&format!(
|
|
"use of SIMD type{} in FFI is highly experimental and \
|
|
may result in invalid code",
|
|
snip
|
|
),
|
|
)
|
|
.help("add `#![feature(simd_ffi)]` to the crate attributes to enable")
|
|
.emit();
|
|
}
|
|
};
|
|
for (input, ty) in iter::zip(decl.inputs, fty.inputs().skip_binder()) {
|
|
check(input, *ty)
|
|
}
|
|
if let hir::FnRetTy::Return(ref ty) = decl.output {
|
|
check(ty, fty.output().skip_binder())
|
|
}
|
|
}
|
|
|
|
fty
|
|
}
|
|
|
|
fn is_foreign_item(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
|
|
match tcx.hir().get_if_local(def_id) {
|
|
Some(Node::ForeignItem(..)) => true,
|
|
Some(_) => false,
|
|
_ => bug!("is_foreign_item applied to non-local def-id {:?}", def_id),
|
|
}
|
|
}
|
|
|
|
fn generator_kind(tcx: TyCtxt<'_>, def_id: DefId) -> Option<hir::GeneratorKind> {
|
|
match tcx.hir().get_if_local(def_id) {
|
|
Some(Node::Expr(&rustc_hir::Expr {
|
|
kind: rustc_hir::ExprKind::Closure(&rustc_hir::Closure { body, .. }),
|
|
..
|
|
})) => tcx.hir().body(body).generator_kind(),
|
|
Some(_) => None,
|
|
_ => bug!("generator_kind applied to non-local def-id {:?}", def_id),
|
|
}
|
|
}
|
|
|
|
fn from_target_feature(
|
|
tcx: TyCtxt<'_>,
|
|
attr: &ast::Attribute,
|
|
supported_target_features: &FxHashMap<String, Option<Symbol>>,
|
|
target_features: &mut Vec<Symbol>,
|
|
) {
|
|
let Some(list) = attr.meta_item_list() else { return };
|
|
let bad_item = |span| {
|
|
let msg = "malformed `target_feature` attribute input";
|
|
let code = "enable = \"..\"";
|
|
tcx.sess
|
|
.struct_span_err(span, msg)
|
|
.span_suggestion(span, "must be of the form", code, Applicability::HasPlaceholders)
|
|
.emit();
|
|
};
|
|
let rust_features = tcx.features();
|
|
for item in list {
|
|
// Only `enable = ...` is accepted in the meta-item list.
|
|
if !item.has_name(sym::enable) {
|
|
bad_item(item.span());
|
|
continue;
|
|
}
|
|
|
|
// Must be of the form `enable = "..."` (a string).
|
|
let Some(value) = item.value_str() else {
|
|
bad_item(item.span());
|
|
continue;
|
|
};
|
|
|
|
// We allow comma separation to enable multiple features.
|
|
target_features.extend(value.as_str().split(',').filter_map(|feature| {
|
|
let Some(feature_gate) = supported_target_features.get(feature) else {
|
|
let msg =
|
|
format!("the feature named `{}` is not valid for this target", feature);
|
|
let mut err = tcx.sess.struct_span_err(item.span(), &msg);
|
|
err.span_label(
|
|
item.span(),
|
|
format!("`{}` is not valid for this target", feature),
|
|
);
|
|
if let Some(stripped) = feature.strip_prefix('+') {
|
|
let valid = supported_target_features.contains_key(stripped);
|
|
if valid {
|
|
err.help("consider removing the leading `+` in the feature name");
|
|
}
|
|
}
|
|
err.emit();
|
|
return None;
|
|
};
|
|
|
|
// Only allow features whose feature gates have been enabled.
|
|
let allowed = match feature_gate.as_ref().copied() {
|
|
Some(sym::arm_target_feature) => rust_features.arm_target_feature,
|
|
Some(sym::hexagon_target_feature) => rust_features.hexagon_target_feature,
|
|
Some(sym::powerpc_target_feature) => rust_features.powerpc_target_feature,
|
|
Some(sym::mips_target_feature) => rust_features.mips_target_feature,
|
|
Some(sym::riscv_target_feature) => rust_features.riscv_target_feature,
|
|
Some(sym::avx512_target_feature) => rust_features.avx512_target_feature,
|
|
Some(sym::sse4a_target_feature) => rust_features.sse4a_target_feature,
|
|
Some(sym::tbm_target_feature) => rust_features.tbm_target_feature,
|
|
Some(sym::wasm_target_feature) => rust_features.wasm_target_feature,
|
|
Some(sym::cmpxchg16b_target_feature) => rust_features.cmpxchg16b_target_feature,
|
|
Some(sym::movbe_target_feature) => rust_features.movbe_target_feature,
|
|
Some(sym::rtm_target_feature) => rust_features.rtm_target_feature,
|
|
Some(sym::f16c_target_feature) => rust_features.f16c_target_feature,
|
|
Some(sym::ermsb_target_feature) => rust_features.ermsb_target_feature,
|
|
Some(sym::bpf_target_feature) => rust_features.bpf_target_feature,
|
|
Some(sym::aarch64_ver_target_feature) => rust_features.aarch64_ver_target_feature,
|
|
Some(name) => bug!("unknown target feature gate {}", name),
|
|
None => true,
|
|
};
|
|
if !allowed {
|
|
feature_err(
|
|
&tcx.sess.parse_sess,
|
|
feature_gate.unwrap(),
|
|
item.span(),
|
|
&format!("the target feature `{}` is currently unstable", feature),
|
|
)
|
|
.emit();
|
|
}
|
|
Some(Symbol::intern(feature))
|
|
}));
|
|
}
|
|
}
|
|
|
|
fn linkage_by_name(tcx: TyCtxt<'_>, def_id: LocalDefId, name: &str) -> Linkage {
|
|
use rustc_middle::mir::mono::Linkage::*;
|
|
|
|
// Use the names from src/llvm/docs/LangRef.rst here. Most types are only
|
|
// applicable to variable declarations and may not really make sense for
|
|
// Rust code in the first place but allow them anyway and trust that the
|
|
// user knows what they're doing. Who knows, unanticipated use cases may pop
|
|
// up in the future.
|
|
//
|
|
// ghost, dllimport, dllexport and linkonce_odr_autohide are not supported
|
|
// and don't have to be, LLVM treats them as no-ops.
|
|
match name {
|
|
"appending" => Appending,
|
|
"available_externally" => AvailableExternally,
|
|
"common" => Common,
|
|
"extern_weak" => ExternalWeak,
|
|
"external" => External,
|
|
"internal" => Internal,
|
|
"linkonce" => LinkOnceAny,
|
|
"linkonce_odr" => LinkOnceODR,
|
|
"private" => Private,
|
|
"weak" => WeakAny,
|
|
"weak_odr" => WeakODR,
|
|
_ => tcx.sess.span_fatal(tcx.def_span(def_id), "invalid linkage specified"),
|
|
}
|
|
}
|
|
|
|
fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: DefId) -> CodegenFnAttrs {
|
|
if cfg!(debug_assertions) {
|
|
let def_kind = tcx.def_kind(did);
|
|
assert!(
|
|
def_kind.has_codegen_attrs(),
|
|
"unexpected `def_kind` in `codegen_fn_attrs`: {def_kind:?}",
|
|
);
|
|
}
|
|
|
|
let did = did.expect_local();
|
|
let attrs = tcx.hir().attrs(tcx.hir().local_def_id_to_hir_id(did));
|
|
let mut codegen_fn_attrs = CodegenFnAttrs::new();
|
|
if tcx.should_inherit_track_caller(did) {
|
|
codegen_fn_attrs.flags |= CodegenFnAttrFlags::TRACK_CALLER;
|
|
}
|
|
|
|
// The panic_no_unwind function called by TerminatorKind::Abort will never
|
|
// unwind. If the panic handler that it invokes unwind then it will simply
|
|
// call the panic handler again.
|
|
if Some(did.to_def_id()) == tcx.lang_items().panic_no_unwind() {
|
|
codegen_fn_attrs.flags |= CodegenFnAttrFlags::NEVER_UNWIND;
|
|
}
|
|
|
|
let supported_target_features = tcx.supported_target_features(LOCAL_CRATE);
|
|
|
|
let mut inline_span = None;
|
|
let mut link_ordinal_span = None;
|
|
let mut no_sanitize_span = None;
|
|
for attr in attrs.iter() {
|
|
if attr.has_name(sym::cold) {
|
|
codegen_fn_attrs.flags |= CodegenFnAttrFlags::COLD;
|
|
} else if attr.has_name(sym::rustc_allocator) {
|
|
codegen_fn_attrs.flags |= CodegenFnAttrFlags::ALLOCATOR;
|
|
} else if attr.has_name(sym::ffi_returns_twice) {
|
|
if tcx.is_foreign_item(did) {
|
|
codegen_fn_attrs.flags |= CodegenFnAttrFlags::FFI_RETURNS_TWICE;
|
|
} else {
|
|
// `#[ffi_returns_twice]` is only allowed `extern fn`s.
|
|
struct_span_err!(
|
|
tcx.sess,
|
|
attr.span,
|
|
E0724,
|
|
"`#[ffi_returns_twice]` may only be used on foreign functions"
|
|
)
|
|
.emit();
|
|
}
|
|
} else if attr.has_name(sym::ffi_pure) {
|
|
if tcx.is_foreign_item(did) {
|
|
if attrs.iter().any(|a| a.has_name(sym::ffi_const)) {
|
|
// `#[ffi_const]` functions cannot be `#[ffi_pure]`
|
|
struct_span_err!(
|
|
tcx.sess,
|
|
attr.span,
|
|
E0757,
|
|
"`#[ffi_const]` function cannot be `#[ffi_pure]`"
|
|
)
|
|
.emit();
|
|
} else {
|
|
codegen_fn_attrs.flags |= CodegenFnAttrFlags::FFI_PURE;
|
|
}
|
|
} else {
|
|
// `#[ffi_pure]` is only allowed on foreign functions
|
|
struct_span_err!(
|
|
tcx.sess,
|
|
attr.span,
|
|
E0755,
|
|
"`#[ffi_pure]` may only be used on foreign functions"
|
|
)
|
|
.emit();
|
|
}
|
|
} else if attr.has_name(sym::ffi_const) {
|
|
if tcx.is_foreign_item(did) {
|
|
codegen_fn_attrs.flags |= CodegenFnAttrFlags::FFI_CONST;
|
|
} else {
|
|
// `#[ffi_const]` is only allowed on foreign functions
|
|
struct_span_err!(
|
|
tcx.sess,
|
|
attr.span,
|
|
E0756,
|
|
"`#[ffi_const]` may only be used on foreign functions"
|
|
)
|
|
.emit();
|
|
}
|
|
} else if attr.has_name(sym::rustc_allocator_nounwind) {
|
|
codegen_fn_attrs.flags |= CodegenFnAttrFlags::NEVER_UNWIND;
|
|
} else if attr.has_name(sym::rustc_reallocator) {
|
|
codegen_fn_attrs.flags |= CodegenFnAttrFlags::REALLOCATOR;
|
|
} else if attr.has_name(sym::rustc_deallocator) {
|
|
codegen_fn_attrs.flags |= CodegenFnAttrFlags::DEALLOCATOR;
|
|
} else if attr.has_name(sym::rustc_allocator_zeroed) {
|
|
codegen_fn_attrs.flags |= CodegenFnAttrFlags::ALLOCATOR_ZEROED;
|
|
} else if attr.has_name(sym::naked) {
|
|
codegen_fn_attrs.flags |= CodegenFnAttrFlags::NAKED;
|
|
} else if attr.has_name(sym::no_mangle) {
|
|
codegen_fn_attrs.flags |= CodegenFnAttrFlags::NO_MANGLE;
|
|
} else if attr.has_name(sym::no_coverage) {
|
|
codegen_fn_attrs.flags |= CodegenFnAttrFlags::NO_COVERAGE;
|
|
} else if attr.has_name(sym::rustc_std_internal_symbol) {
|
|
codegen_fn_attrs.flags |= CodegenFnAttrFlags::RUSTC_STD_INTERNAL_SYMBOL;
|
|
} else if attr.has_name(sym::used) {
|
|
let inner = attr.meta_item_list();
|
|
match inner.as_deref() {
|
|
Some([item]) if item.has_name(sym::linker) => {
|
|
if !tcx.features().used_with_arg {
|
|
feature_err(
|
|
&tcx.sess.parse_sess,
|
|
sym::used_with_arg,
|
|
attr.span,
|
|
"`#[used(linker)]` is currently unstable",
|
|
)
|
|
.emit();
|
|
}
|
|
codegen_fn_attrs.flags |= CodegenFnAttrFlags::USED_LINKER;
|
|
}
|
|
Some([item]) if item.has_name(sym::compiler) => {
|
|
if !tcx.features().used_with_arg {
|
|
feature_err(
|
|
&tcx.sess.parse_sess,
|
|
sym::used_with_arg,
|
|
attr.span,
|
|
"`#[used(compiler)]` is currently unstable",
|
|
)
|
|
.emit();
|
|
}
|
|
codegen_fn_attrs.flags |= CodegenFnAttrFlags::USED;
|
|
}
|
|
Some(_) => {
|
|
tcx.sess.emit_err(errors::ExpectedUsedSymbol { span: attr.span });
|
|
}
|
|
None => {
|
|
// Unfortunately, unconditionally using `llvm.used` causes
|
|
// issues in handling `.init_array` with the gold linker,
|
|
// but using `llvm.compiler.used` caused a nontrival amount
|
|
// of unintentional ecosystem breakage -- particularly on
|
|
// Mach-O targets.
|
|
//
|
|
// As a result, we emit `llvm.compiler.used` only on ELF
|
|
// targets. This is somewhat ad-hoc, but actually follows
|
|
// our pre-LLVM 13 behavior (prior to the ecosystem
|
|
// breakage), and seems to match `clang`'s behavior as well
|
|
// (both before and after LLVM 13), possibly because they
|
|
// have similar compatibility concerns to us. See
|
|
// https://github.com/rust-lang/rust/issues/47384#issuecomment-1019080146
|
|
// and following comments for some discussion of this, as
|
|
// well as the comments in `rustc_codegen_llvm` where these
|
|
// flags are handled.
|
|
//
|
|
// Anyway, to be clear: this is still up in the air
|
|
// somewhat, and is subject to change in the future (which
|
|
// is a good thing, because this would ideally be a bit
|
|
// more firmed up).
|
|
let is_like_elf = !(tcx.sess.target.is_like_osx
|
|
|| tcx.sess.target.is_like_windows
|
|
|| tcx.sess.target.is_like_wasm);
|
|
codegen_fn_attrs.flags |= if is_like_elf {
|
|
CodegenFnAttrFlags::USED
|
|
} else {
|
|
CodegenFnAttrFlags::USED_LINKER
|
|
};
|
|
}
|
|
}
|
|
} else if attr.has_name(sym::cmse_nonsecure_entry) {
|
|
if !matches!(tcx.fn_sig(did).abi(), abi::Abi::C { .. }) {
|
|
struct_span_err!(
|
|
tcx.sess,
|
|
attr.span,
|
|
E0776,
|
|
"`#[cmse_nonsecure_entry]` requires C ABI"
|
|
)
|
|
.emit();
|
|
}
|
|
if !tcx.sess.target.llvm_target.contains("thumbv8m") {
|
|
struct_span_err!(tcx.sess, attr.span, E0775, "`#[cmse_nonsecure_entry]` is only valid for targets with the TrustZone-M extension")
|
|
.emit();
|
|
}
|
|
codegen_fn_attrs.flags |= CodegenFnAttrFlags::CMSE_NONSECURE_ENTRY;
|
|
} else if attr.has_name(sym::thread_local) {
|
|
codegen_fn_attrs.flags |= CodegenFnAttrFlags::THREAD_LOCAL;
|
|
} else if attr.has_name(sym::track_caller) {
|
|
if !tcx.is_closure(did.to_def_id()) && tcx.fn_sig(did).abi() != abi::Abi::Rust {
|
|
struct_span_err!(tcx.sess, attr.span, E0737, "`#[track_caller]` requires Rust ABI")
|
|
.emit();
|
|
}
|
|
if tcx.is_closure(did.to_def_id()) && !tcx.features().closure_track_caller {
|
|
feature_err(
|
|
&tcx.sess.parse_sess,
|
|
sym::closure_track_caller,
|
|
attr.span,
|
|
"`#[track_caller]` on closures is currently unstable",
|
|
)
|
|
.emit();
|
|
}
|
|
codegen_fn_attrs.flags |= CodegenFnAttrFlags::TRACK_CALLER;
|
|
} else if attr.has_name(sym::export_name) {
|
|
if let Some(s) = attr.value_str() {
|
|
if s.as_str().contains('\0') {
|
|
// `#[export_name = ...]` will be converted to a null-terminated string,
|
|
// so it may not contain any null characters.
|
|
struct_span_err!(
|
|
tcx.sess,
|
|
attr.span,
|
|
E0648,
|
|
"`export_name` may not contain null characters"
|
|
)
|
|
.emit();
|
|
}
|
|
codegen_fn_attrs.export_name = Some(s);
|
|
}
|
|
} else if attr.has_name(sym::target_feature) {
|
|
if !tcx.is_closure(did.to_def_id())
|
|
&& tcx.fn_sig(did).unsafety() == hir::Unsafety::Normal
|
|
{
|
|
if tcx.sess.target.is_like_wasm || tcx.sess.opts.actually_rustdoc {
|
|
// The `#[target_feature]` attribute is allowed on
|
|
// WebAssembly targets on all functions, including safe
|
|
// ones. Other targets require that `#[target_feature]` is
|
|
// only applied to unsafe functions (pending the
|
|
// `target_feature_11` feature) because on most targets
|
|
// execution of instructions that are not supported is
|
|
// considered undefined behavior. For WebAssembly which is a
|
|
// 100% safe target at execution time it's not possible to
|
|
// execute undefined instructions, and even if a future
|
|
// feature was added in some form for this it would be a
|
|
// deterministic trap. There is no undefined behavior when
|
|
// executing WebAssembly so `#[target_feature]` is allowed
|
|
// on safe functions (but again, only for WebAssembly)
|
|
//
|
|
// Note that this is also allowed if `actually_rustdoc` so
|
|
// if a target is documenting some wasm-specific code then
|
|
// it's not spuriously denied.
|
|
} else if !tcx.features().target_feature_11 {
|
|
let mut err = feature_err(
|
|
&tcx.sess.parse_sess,
|
|
sym::target_feature_11,
|
|
attr.span,
|
|
"`#[target_feature(..)]` can only be applied to `unsafe` functions",
|
|
);
|
|
err.span_label(tcx.def_span(did), "not an `unsafe` function");
|
|
err.emit();
|
|
} else {
|
|
check_target_feature_trait_unsafe(tcx, did, attr.span);
|
|
}
|
|
}
|
|
from_target_feature(
|
|
tcx,
|
|
attr,
|
|
supported_target_features,
|
|
&mut codegen_fn_attrs.target_features,
|
|
);
|
|
} else if attr.has_name(sym::linkage) {
|
|
if let Some(val) = attr.value_str() {
|
|
codegen_fn_attrs.linkage = Some(linkage_by_name(tcx, did, val.as_str()));
|
|
}
|
|
} else if attr.has_name(sym::link_section) {
|
|
if let Some(val) = attr.value_str() {
|
|
if val.as_str().bytes().any(|b| b == 0) {
|
|
let msg = format!(
|
|
"illegal null byte in link_section \
|
|
value: `{}`",
|
|
&val
|
|
);
|
|
tcx.sess.span_err(attr.span, &msg);
|
|
} else {
|
|
codegen_fn_attrs.link_section = Some(val);
|
|
}
|
|
}
|
|
} else if attr.has_name(sym::link_name) {
|
|
codegen_fn_attrs.link_name = attr.value_str();
|
|
} else if attr.has_name(sym::link_ordinal) {
|
|
link_ordinal_span = Some(attr.span);
|
|
if let ordinal @ Some(_) = check_link_ordinal(tcx, attr) {
|
|
codegen_fn_attrs.link_ordinal = ordinal;
|
|
}
|
|
} else if attr.has_name(sym::no_sanitize) {
|
|
no_sanitize_span = Some(attr.span);
|
|
if let Some(list) = attr.meta_item_list() {
|
|
for item in list.iter() {
|
|
if item.has_name(sym::address) {
|
|
codegen_fn_attrs.no_sanitize |= SanitizerSet::ADDRESS;
|
|
} else if item.has_name(sym::cfi) {
|
|
codegen_fn_attrs.no_sanitize |= SanitizerSet::CFI;
|
|
} else if item.has_name(sym::memory) {
|
|
codegen_fn_attrs.no_sanitize |= SanitizerSet::MEMORY;
|
|
} else if item.has_name(sym::memtag) {
|
|
codegen_fn_attrs.no_sanitize |= SanitizerSet::MEMTAG;
|
|
} else if item.has_name(sym::shadow_call_stack) {
|
|
codegen_fn_attrs.no_sanitize |= SanitizerSet::SHADOWCALLSTACK;
|
|
} else if item.has_name(sym::thread) {
|
|
codegen_fn_attrs.no_sanitize |= SanitizerSet::THREAD;
|
|
} else if item.has_name(sym::hwaddress) {
|
|
codegen_fn_attrs.no_sanitize |= SanitizerSet::HWADDRESS;
|
|
} else {
|
|
tcx.sess
|
|
.struct_span_err(item.span(), "invalid argument for `no_sanitize`")
|
|
.note("expected one of: `address`, `cfi`, `hwaddress`, `memory`, `memtag`, `shadow-call-stack`, or `thread`")
|
|
.emit();
|
|
}
|
|
}
|
|
}
|
|
} else if attr.has_name(sym::instruction_set) {
|
|
codegen_fn_attrs.instruction_set = match attr.meta_kind() {
|
|
Some(MetaItemKind::List(ref items)) => match items.as_slice() {
|
|
[NestedMetaItem::MetaItem(set)] => {
|
|
let segments =
|
|
set.path.segments.iter().map(|x| x.ident.name).collect::<Vec<_>>();
|
|
match segments.as_slice() {
|
|
[sym::arm, sym::a32] | [sym::arm, sym::t32] => {
|
|
if !tcx.sess.target.has_thumb_interworking {
|
|
struct_span_err!(
|
|
tcx.sess.diagnostic(),
|
|
attr.span,
|
|
E0779,
|
|
"target does not support `#[instruction_set]`"
|
|
)
|
|
.emit();
|
|
None
|
|
} else if segments[1] == sym::a32 {
|
|
Some(InstructionSetAttr::ArmA32)
|
|
} else if segments[1] == sym::t32 {
|
|
Some(InstructionSetAttr::ArmT32)
|
|
} else {
|
|
unreachable!()
|
|
}
|
|
}
|
|
_ => {
|
|
struct_span_err!(
|
|
tcx.sess.diagnostic(),
|
|
attr.span,
|
|
E0779,
|
|
"invalid instruction set specified",
|
|
)
|
|
.emit();
|
|
None
|
|
}
|
|
}
|
|
}
|
|
[] => {
|
|
struct_span_err!(
|
|
tcx.sess.diagnostic(),
|
|
attr.span,
|
|
E0778,
|
|
"`#[instruction_set]` requires an argument"
|
|
)
|
|
.emit();
|
|
None
|
|
}
|
|
_ => {
|
|
struct_span_err!(
|
|
tcx.sess.diagnostic(),
|
|
attr.span,
|
|
E0779,
|
|
"cannot specify more than one instruction set"
|
|
)
|
|
.emit();
|
|
None
|
|
}
|
|
},
|
|
_ => {
|
|
struct_span_err!(
|
|
tcx.sess.diagnostic(),
|
|
attr.span,
|
|
E0778,
|
|
"must specify an instruction set"
|
|
)
|
|
.emit();
|
|
None
|
|
}
|
|
};
|
|
} else if attr.has_name(sym::repr) {
|
|
codegen_fn_attrs.alignment = match attr.meta_item_list() {
|
|
Some(items) => match items.as_slice() {
|
|
[item] => match item.name_value_literal() {
|
|
Some((sym::align, literal)) => {
|
|
let alignment = rustc_attr::parse_alignment(&literal.kind);
|
|
|
|
match alignment {
|
|
Ok(align) => Some(align),
|
|
Err(msg) => {
|
|
struct_span_err!(
|
|
tcx.sess.diagnostic(),
|
|
attr.span,
|
|
E0589,
|
|
"invalid `repr(align)` attribute: {}",
|
|
msg
|
|
)
|
|
.emit();
|
|
|
|
None
|
|
}
|
|
}
|
|
}
|
|
_ => None,
|
|
},
|
|
[] => None,
|
|
_ => None,
|
|
},
|
|
None => None,
|
|
};
|
|
}
|
|
}
|
|
|
|
codegen_fn_attrs.inline = attrs.iter().fold(InlineAttr::None, |ia, attr| {
|
|
if !attr.has_name(sym::inline) {
|
|
return ia;
|
|
}
|
|
match attr.meta_kind() {
|
|
Some(MetaItemKind::Word) => InlineAttr::Hint,
|
|
Some(MetaItemKind::List(ref items)) => {
|
|
inline_span = Some(attr.span);
|
|
if items.len() != 1 {
|
|
struct_span_err!(
|
|
tcx.sess.diagnostic(),
|
|
attr.span,
|
|
E0534,
|
|
"expected one argument"
|
|
)
|
|
.emit();
|
|
InlineAttr::None
|
|
} else if list_contains_name(&items, sym::always) {
|
|
InlineAttr::Always
|
|
} else if list_contains_name(&items, sym::never) {
|
|
InlineAttr::Never
|
|
} else {
|
|
struct_span_err!(
|
|
tcx.sess.diagnostic(),
|
|
items[0].span(),
|
|
E0535,
|
|
"invalid argument"
|
|
)
|
|
.help("valid inline arguments are `always` and `never`")
|
|
.emit();
|
|
|
|
InlineAttr::None
|
|
}
|
|
}
|
|
Some(MetaItemKind::NameValue(_)) => ia,
|
|
None => ia,
|
|
}
|
|
});
|
|
|
|
codegen_fn_attrs.optimize = attrs.iter().fold(OptimizeAttr::None, |ia, attr| {
|
|
if !attr.has_name(sym::optimize) {
|
|
return ia;
|
|
}
|
|
let err = |sp, s| struct_span_err!(tcx.sess.diagnostic(), sp, E0722, "{}", s).emit();
|
|
match attr.meta_kind() {
|
|
Some(MetaItemKind::Word) => {
|
|
err(attr.span, "expected one argument");
|
|
ia
|
|
}
|
|
Some(MetaItemKind::List(ref items)) => {
|
|
inline_span = Some(attr.span);
|
|
if items.len() != 1 {
|
|
err(attr.span, "expected one argument");
|
|
OptimizeAttr::None
|
|
} else if list_contains_name(&items, sym::size) {
|
|
OptimizeAttr::Size
|
|
} else if list_contains_name(&items, sym::speed) {
|
|
OptimizeAttr::Speed
|
|
} else {
|
|
err(items[0].span(), "invalid argument");
|
|
OptimizeAttr::None
|
|
}
|
|
}
|
|
Some(MetaItemKind::NameValue(_)) => ia,
|
|
None => ia,
|
|
}
|
|
});
|
|
|
|
// #73631: closures inherit `#[target_feature]` annotations
|
|
if tcx.features().target_feature_11 && tcx.is_closure(did.to_def_id()) {
|
|
let owner_id = tcx.parent(did.to_def_id());
|
|
if tcx.def_kind(owner_id).has_codegen_attrs() {
|
|
codegen_fn_attrs
|
|
.target_features
|
|
.extend(tcx.codegen_fn_attrs(owner_id).target_features.iter().copied());
|
|
}
|
|
}
|
|
|
|
// If a function uses #[target_feature] it can't be inlined into general
|
|
// purpose functions as they wouldn't have the right target features
|
|
// enabled. For that reason we also forbid #[inline(always)] as it can't be
|
|
// respected.
|
|
if !codegen_fn_attrs.target_features.is_empty() {
|
|
if codegen_fn_attrs.inline == InlineAttr::Always {
|
|
if let Some(span) = inline_span {
|
|
tcx.sess.span_err(
|
|
span,
|
|
"cannot use `#[inline(always)]` with \
|
|
`#[target_feature]`",
|
|
);
|
|
}
|
|
}
|
|
}
|
|
|
|
if !codegen_fn_attrs.no_sanitize.is_empty() {
|
|
if codegen_fn_attrs.inline == InlineAttr::Always {
|
|
if let (Some(no_sanitize_span), Some(inline_span)) = (no_sanitize_span, inline_span) {
|
|
let hir_id = tcx.hir().local_def_id_to_hir_id(did);
|
|
tcx.struct_span_lint_hir(
|
|
lint::builtin::INLINE_NO_SANITIZE,
|
|
hir_id,
|
|
no_sanitize_span,
|
|
|lint| {
|
|
lint.build("`no_sanitize` will have no effect after inlining")
|
|
.span_note(inline_span, "inlining requested here")
|
|
.emit();
|
|
},
|
|
)
|
|
}
|
|
}
|
|
}
|
|
|
|
// Weak lang items have the same semantics as "std internal" symbols in the
|
|
// sense that they're preserved through all our LTO passes and only
|
|
// strippable by the linker.
|
|
//
|
|
// Additionally weak lang items have predetermined symbol names.
|
|
if tcx.is_weak_lang_item(did.to_def_id()) {
|
|
codegen_fn_attrs.flags |= CodegenFnAttrFlags::RUSTC_STD_INTERNAL_SYMBOL;
|
|
}
|
|
if let Some(name) = weak_lang_items::link_name(attrs) {
|
|
codegen_fn_attrs.export_name = Some(name);
|
|
codegen_fn_attrs.link_name = Some(name);
|
|
}
|
|
check_link_name_xor_ordinal(tcx, &codegen_fn_attrs, link_ordinal_span);
|
|
|
|
// Internal symbols to the standard library all have no_mangle semantics in
|
|
// that they have defined symbol names present in the function name. This
|
|
// also applies to weak symbols where they all have known symbol names.
|
|
if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::RUSTC_STD_INTERNAL_SYMBOL) {
|
|
codegen_fn_attrs.flags |= CodegenFnAttrFlags::NO_MANGLE;
|
|
}
|
|
|
|
// Any linkage to LLVM intrinsics for now forcibly marks them all as never
|
|
// unwinds since LLVM sometimes can't handle codegen which `invoke`s
|
|
// intrinsic functions.
|
|
if let Some(name) = &codegen_fn_attrs.link_name {
|
|
if name.as_str().starts_with("llvm.") {
|
|
codegen_fn_attrs.flags |= CodegenFnAttrFlags::NEVER_UNWIND;
|
|
}
|
|
}
|
|
|
|
codegen_fn_attrs
|
|
}
|
|
|
|
/// Computes the set of target features used in a function for the purposes of
|
|
/// inline assembly.
|
|
fn asm_target_features<'tcx>(tcx: TyCtxt<'tcx>, did: DefId) -> &'tcx FxHashSet<Symbol> {
|
|
let mut target_features = tcx.sess.unstable_target_features.clone();
|
|
if tcx.def_kind(did).has_codegen_attrs() {
|
|
let attrs = tcx.codegen_fn_attrs(did);
|
|
target_features.extend(&attrs.target_features);
|
|
match attrs.instruction_set {
|
|
None => {}
|
|
Some(InstructionSetAttr::ArmA32) => {
|
|
target_features.remove(&sym::thumb_mode);
|
|
}
|
|
Some(InstructionSetAttr::ArmT32) => {
|
|
target_features.insert(sym::thumb_mode);
|
|
}
|
|
}
|
|
}
|
|
|
|
tcx.arena.alloc(target_features)
|
|
}
|
|
|
|
/// Checks if the provided DefId is a method in a trait impl for a trait which has track_caller
|
|
/// applied to the method prototype.
|
|
fn should_inherit_track_caller(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
|
|
if let Some(impl_item) = tcx.opt_associated_item(def_id)
|
|
&& let ty::AssocItemContainer::ImplContainer = impl_item.container
|
|
&& let Some(trait_item) = impl_item.trait_item_def_id
|
|
{
|
|
return tcx
|
|
.codegen_fn_attrs(trait_item)
|
|
.flags
|
|
.intersects(CodegenFnAttrFlags::TRACK_CALLER);
|
|
}
|
|
|
|
false
|
|
}
|
|
|
|
fn check_link_ordinal(tcx: TyCtxt<'_>, attr: &ast::Attribute) -> Option<u16> {
|
|
use rustc_ast::{Lit, LitIntType, LitKind};
|
|
if !tcx.features().raw_dylib && tcx.sess.target.arch == "x86" {
|
|
feature_err(
|
|
&tcx.sess.parse_sess,
|
|
sym::raw_dylib,
|
|
attr.span,
|
|
"`#[link_ordinal]` is unstable on x86",
|
|
)
|
|
.emit();
|
|
}
|
|
let meta_item_list = attr.meta_item_list();
|
|
let meta_item_list: Option<&[ast::NestedMetaItem]> = meta_item_list.as_ref().map(Vec::as_ref);
|
|
let sole_meta_list = match meta_item_list {
|
|
Some([item]) => item.literal(),
|
|
Some(_) => {
|
|
tcx.sess
|
|
.struct_span_err(attr.span, "incorrect number of arguments to `#[link_ordinal]`")
|
|
.note("the attribute requires exactly one argument")
|
|
.emit();
|
|
return None;
|
|
}
|
|
_ => None,
|
|
};
|
|
if let Some(Lit { kind: LitKind::Int(ordinal, LitIntType::Unsuffixed), .. }) = sole_meta_list {
|
|
// According to the table at https://docs.microsoft.com/en-us/windows/win32/debug/pe-format#import-header,
|
|
// the ordinal must fit into 16 bits. Similarly, the Ordinal field in COFFShortExport (defined
|
|
// in llvm/include/llvm/Object/COFFImportFile.h), which we use to communicate import information
|
|
// to LLVM for `#[link(kind = "raw-dylib"_])`, is also defined to be uint16_t.
|
|
//
|
|
// FIXME: should we allow an ordinal of 0? The MSVC toolchain has inconsistent support for this:
|
|
// both LINK.EXE and LIB.EXE signal errors and abort when given a .DEF file that specifies
|
|
// a zero ordinal. However, llvm-dlltool is perfectly happy to generate an import library
|
|
// for such a .DEF file, and MSVC's LINK.EXE is also perfectly happy to consume an import
|
|
// library produced by LLVM with an ordinal of 0, and it generates an .EXE. (I don't know yet
|
|
// if the resulting EXE runs, as I haven't yet built the necessary DLL -- see earlier comment
|
|
// about LINK.EXE failing.)
|
|
if *ordinal <= u16::MAX as u128 {
|
|
Some(*ordinal as u16)
|
|
} else {
|
|
let msg = format!("ordinal value in `link_ordinal` is too large: `{}`", &ordinal);
|
|
tcx.sess
|
|
.struct_span_err(attr.span, &msg)
|
|
.note("the value may not exceed `u16::MAX`")
|
|
.emit();
|
|
None
|
|
}
|
|
} else {
|
|
tcx.sess
|
|
.struct_span_err(attr.span, "illegal ordinal format in `link_ordinal`")
|
|
.note("an unsuffixed integer value, e.g., `1`, is expected")
|
|
.emit();
|
|
None
|
|
}
|
|
}
|
|
|
|
fn check_link_name_xor_ordinal(
|
|
tcx: TyCtxt<'_>,
|
|
codegen_fn_attrs: &CodegenFnAttrs,
|
|
inline_span: Option<Span>,
|
|
) {
|
|
if codegen_fn_attrs.link_name.is_none() || codegen_fn_attrs.link_ordinal.is_none() {
|
|
return;
|
|
}
|
|
let msg = "cannot use `#[link_name]` with `#[link_ordinal]`";
|
|
if let Some(span) = inline_span {
|
|
tcx.sess.span_err(span, msg);
|
|
} else {
|
|
tcx.sess.err(msg);
|
|
}
|
|
}
|
|
|
|
/// Checks the function annotated with `#[target_feature]` is not a safe
|
|
/// trait method implementation, reporting an error if it is.
|
|
fn check_target_feature_trait_unsafe(tcx: TyCtxt<'_>, id: LocalDefId, attr_span: Span) {
|
|
let hir_id = tcx.hir().local_def_id_to_hir_id(id);
|
|
let node = tcx.hir().get(hir_id);
|
|
if let Node::ImplItem(hir::ImplItem { kind: hir::ImplItemKind::Fn(..), .. }) = node {
|
|
let parent_id = tcx.hir().get_parent_item(hir_id);
|
|
let parent_item = tcx.hir().expect_item(parent_id.def_id);
|
|
if let hir::ItemKind::Impl(hir::Impl { of_trait: Some(_), .. }) = parent_item.kind {
|
|
tcx.sess
|
|
.struct_span_err(
|
|
attr_span,
|
|
"`#[target_feature(..)]` cannot be applied to safe trait method",
|
|
)
|
|
.span_label(attr_span, "cannot be applied to safe trait method")
|
|
.span_label(tcx.def_span(id), "not an `unsafe` function")
|
|
.emit();
|
|
}
|
|
}
|
|
}
|