| //! "Collection" is the process of determining the type and other external |
| //! details of each item in Rust. Collection is specifically concerned |
| //! with *inter-procedural* things -- for example, for a function |
| //! definition, collection will figure out the type and signature of the |
| //! function, but it will not visit the *body* of the function in any way, |
| //! nor examine type annotations on local variables (that's the job of |
| //! type *checking*). |
| //! |
| //! Collecting is ultimately defined by a bundle of queries that |
| //! inquire after various facts about the items in the crate (e.g., |
| //! `type_of`, `generics_of`, `predicates_of`, etc). See the `provide` function |
| //! for the full set. |
| //! |
| //! At present, however, we do run collection across all items in the |
| //! crate as a kind of pass. This should eventually be factored away. |
| |
| use crate::astconv::AstConv; |
| use crate::check::intrinsic::intrinsic_operation_unsafety; |
| use crate::errors; |
| use rustc_ast as ast; |
| use rustc_ast::{MetaItemKind, NestedMetaItem}; |
| use rustc_attr::{list_contains_name, InlineAttr, InstructionSetAttr, OptimizeAttr}; |
| use rustc_data_structures::captures::Captures; |
| use rustc_data_structures::fx::{FxHashMap, FxHashSet}; |
| use rustc_errors::{struct_span_err, Applicability, DiagnosticBuilder, ErrorGuaranteed, StashKey}; |
| use rustc_hir as hir; |
| use rustc_hir::def::CtorKind; |
| use rustc_hir::def_id::{DefId, LocalDefId, LOCAL_CRATE}; |
| use rustc_hir::intravisit::{self, Visitor}; |
| use rustc_hir::weak_lang_items; |
| use rustc_hir::{GenericParamKind, Node}; |
| use rustc_middle::hir::nested_filter; |
| use rustc_middle::middle::codegen_fn_attrs::{CodegenFnAttrFlags, CodegenFnAttrs}; |
| use rustc_middle::mir::mono::Linkage; |
| use rustc_middle::ty::query::Providers; |
| use rustc_middle::ty::util::{Discr, IntTypeExt}; |
| use rustc_middle::ty::ReprOptions; |
| use rustc_middle::ty::{self, AdtKind, Const, DefIdTree, IsSuggestable, Ty, TyCtxt}; |
| use rustc_session::lint; |
| use rustc_session::parse::feature_err; |
| use rustc_span::symbol::{kw, sym, Ident, Symbol}; |
| use rustc_span::Span; |
| use rustc_target::spec::{abi, SanitizerSet}; |
| use rustc_trait_selection::traits::error_reporting::suggestions::NextTypeParamName; |
| use std::iter; |
| |
| mod generics_of; |
| mod item_bounds; |
| mod lifetimes; |
| mod predicates_of; |
| mod type_of; |
| |
| /////////////////////////////////////////////////////////////////////////// |
| // Main entry point |
| |
| fn collect_mod_item_types(tcx: TyCtxt<'_>, module_def_id: LocalDefId) { |
| tcx.hir().visit_item_likes_in_module(module_def_id, &mut CollectItemTypesVisitor { tcx }); |
| } |
| |
| pub fn provide(providers: &mut Providers) { |
| lifetimes::provide(providers); |
| *providers = Providers { |
| opt_const_param_of: type_of::opt_const_param_of, |
| type_of: type_of::type_of, |
| item_bounds: item_bounds::item_bounds, |
| explicit_item_bounds: item_bounds::explicit_item_bounds, |
| generics_of: generics_of::generics_of, |
| predicates_of: predicates_of::predicates_of, |
| predicates_defined_on, |
| explicit_predicates_of: predicates_of::explicit_predicates_of, |
| super_predicates_of: predicates_of::super_predicates_of, |
| super_predicates_that_define_assoc_type: |
| predicates_of::super_predicates_that_define_assoc_type, |
| trait_explicit_predicates_and_bounds: predicates_of::trait_explicit_predicates_and_bounds, |
| type_param_predicates: predicates_of::type_param_predicates, |
| trait_def, |
| adt_def, |
| fn_sig, |
| impl_trait_ref, |
| impl_polarity, |
| is_foreign_item, |
| generator_kind, |
| codegen_fn_attrs, |
| asm_target_features, |
| collect_mod_item_types, |
| should_inherit_track_caller, |
| ..*providers |
| }; |
| } |
| |
| /////////////////////////////////////////////////////////////////////////// |
| |
| /// Context specific to some particular item. This is what implements |
| /// [`AstConv`]. |
| /// |
| /// # `ItemCtxt` vs `FnCtxt` |
| /// |
| /// `ItemCtxt` is primarily used to type-check item signatures and lower them |
| /// from HIR to their [`ty::Ty`] representation, which is exposed using [`AstConv`]. |
| /// It's also used for the bodies of items like structs where the body (the fields) |
| /// are just signatures. |
| /// |
| /// This is in contrast to `FnCtxt`, which is used to type-check bodies of |
| /// functions, closures, and `const`s -- anywhere that expressions and statements show up. |
| /// |
| /// An important thing to note is that `ItemCtxt` does no inference -- it has no [`InferCtxt`] -- |
| /// while `FnCtxt` does do inference. |
| /// |
| /// [`InferCtxt`]: rustc_infer::infer::InferCtxt |
| /// |
| /// # Trait predicates |
| /// |
| /// `ItemCtxt` has information about the predicates that are defined |
| /// on the trait. Unfortunately, this predicate information is |
| /// available in various different forms at various points in the |
| /// process. So we can't just store a pointer to e.g., the AST or the |
| /// parsed ty form, we have to be more flexible. To this end, the |
| /// `ItemCtxt` is parameterized by a `DefId` that it uses to satisfy |
| /// `get_type_parameter_bounds` requests, drawing the information from |
| /// the AST (`hir::Generics`), recursively. |
| pub struct ItemCtxt<'tcx> { |
| tcx: TyCtxt<'tcx>, |
| item_def_id: DefId, |
| } |
| |
| /////////////////////////////////////////////////////////////////////////// |
| |
| #[derive(Default)] |
| pub(crate) struct HirPlaceholderCollector(pub(crate) Vec<Span>); |
| |
| impl<'v> Visitor<'v> for HirPlaceholderCollector { |
| fn visit_ty(&mut self, t: &'v hir::Ty<'v>) { |
| if let hir::TyKind::Infer = t.kind { |
| self.0.push(t.span); |
| } |
| intravisit::walk_ty(self, t) |
| } |
| fn visit_generic_arg(&mut self, generic_arg: &'v hir::GenericArg<'v>) { |
| match generic_arg { |
| hir::GenericArg::Infer(inf) => { |
| self.0.push(inf.span); |
| intravisit::walk_inf(self, inf); |
| } |
| hir::GenericArg::Type(t) => self.visit_ty(t), |
| _ => {} |
| } |
| } |
| fn visit_array_length(&mut self, length: &'v hir::ArrayLen) { |
| if let &hir::ArrayLen::Infer(_, span) = length { |
| self.0.push(span); |
| } |
| intravisit::walk_array_len(self, length) |
| } |
| } |
| |
| struct CollectItemTypesVisitor<'tcx> { |
| tcx: TyCtxt<'tcx>, |
| } |
| |
| /// If there are any placeholder types (`_`), emit an error explaining that this is not allowed |
| /// and suggest adding type parameters in the appropriate place, taking into consideration any and |
| /// all already existing generic type parameters to avoid suggesting a name that is already in use. |
| pub(crate) fn placeholder_type_error<'tcx>( |
| tcx: TyCtxt<'tcx>, |
| generics: Option<&hir::Generics<'_>>, |
| placeholder_types: Vec<Span>, |
| suggest: bool, |
| hir_ty: Option<&hir::Ty<'_>>, |
| kind: &'static str, |
| ) { |
| if placeholder_types.is_empty() { |
| return; |
| } |
| |
| placeholder_type_error_diag(tcx, generics, placeholder_types, vec![], suggest, hir_ty, kind) |
| .emit(); |
| } |
| |
| pub(crate) fn placeholder_type_error_diag<'tcx>( |
| tcx: TyCtxt<'tcx>, |
| generics: Option<&hir::Generics<'_>>, |
| placeholder_types: Vec<Span>, |
| additional_spans: Vec<Span>, |
| suggest: bool, |
| hir_ty: Option<&hir::Ty<'_>>, |
| kind: &'static str, |
| ) -> DiagnosticBuilder<'tcx, ErrorGuaranteed> { |
| if placeholder_types.is_empty() { |
| return bad_placeholder(tcx, additional_spans, kind); |
| } |
| |
| let params = generics.map(|g| g.params).unwrap_or_default(); |
| let type_name = params.next_type_param_name(None); |
| let mut sugg: Vec<_> = |
| placeholder_types.iter().map(|sp| (*sp, (*type_name).to_string())).collect(); |
| |
| if let Some(generics) = generics { |
| if let Some(arg) = params.iter().find(|arg| { |
| matches!(arg.name, hir::ParamName::Plain(Ident { name: kw::Underscore, .. })) |
| }) { |
| // Account for `_` already present in cases like `struct S<_>(_);` and suggest |
| // `struct S<T>(T);` instead of `struct S<_, T>(T);`. |
| sugg.push((arg.span, (*type_name).to_string())); |
| } else if let Some(span) = generics.span_for_param_suggestion() { |
| // Account for bounds, we want `fn foo<T: E, K>(_: K)` not `fn foo<T, K: E>(_: K)`. |
| sugg.push((span, format!(", {}", type_name))); |
| } else { |
| sugg.push((generics.span, format!("<{}>", type_name))); |
| } |
| } |
| |
| let mut err = |
| bad_placeholder(tcx, placeholder_types.into_iter().chain(additional_spans).collect(), kind); |
| |
| // Suggest, but only if it is not a function in const or static |
| if suggest { |
| let mut is_fn = false; |
| let mut is_const_or_static = false; |
| |
| if let Some(hir_ty) = hir_ty && let hir::TyKind::BareFn(_) = hir_ty.kind { |
| is_fn = true; |
| |
| // Check if parent is const or static |
| let parent_id = tcx.hir().get_parent_node(hir_ty.hir_id); |
| let parent_node = tcx.hir().get(parent_id); |
| |
| is_const_or_static = matches!( |
| parent_node, |
| Node::Item(&hir::Item { |
| kind: hir::ItemKind::Const(..) | hir::ItemKind::Static(..), |
| .. |
| }) | Node::TraitItem(&hir::TraitItem { |
| kind: hir::TraitItemKind::Const(..), |
| .. |
| }) | Node::ImplItem(&hir::ImplItem { kind: hir::ImplItemKind::Const(..), .. }) |
| ); |
| } |
| |
| // if function is wrapped around a const or static, |
| // then don't show the suggestion |
| if !(is_fn && is_const_or_static) { |
| err.multipart_suggestion( |
| "use type parameters instead", |
| sugg, |
| Applicability::HasPlaceholders, |
| ); |
| } |
| } |
| |
| err |
| } |
| |
| fn reject_placeholder_type_signatures_in_item<'tcx>( |
| tcx: TyCtxt<'tcx>, |
| item: &'tcx hir::Item<'tcx>, |
| ) { |
| let (generics, suggest) = match &item.kind { |
| hir::ItemKind::Union(_, generics) |
| | hir::ItemKind::Enum(_, generics) |
| | hir::ItemKind::TraitAlias(generics, _) |
| | hir::ItemKind::Trait(_, _, generics, ..) |
| | hir::ItemKind::Impl(hir::Impl { generics, .. }) |
| | hir::ItemKind::Struct(_, generics) => (generics, true), |
| hir::ItemKind::OpaqueTy(hir::OpaqueTy { generics, .. }) |
| | hir::ItemKind::TyAlias(_, generics) => (generics, false), |
| // `static`, `fn` and `const` are handled elsewhere to suggest appropriate type. |
| _ => return, |
| }; |
| |
| let mut visitor = HirPlaceholderCollector::default(); |
| visitor.visit_item(item); |
| |
| placeholder_type_error(tcx, Some(generics), visitor.0, suggest, None, item.kind.descr()); |
| } |
| |
| impl<'tcx> Visitor<'tcx> for CollectItemTypesVisitor<'tcx> { |
| type NestedFilter = nested_filter::OnlyBodies; |
| |
| fn nested_visit_map(&mut self) -> Self::Map { |
| self.tcx.hir() |
| } |
| |
| fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) { |
| convert_item(self.tcx, item.item_id()); |
| reject_placeholder_type_signatures_in_item(self.tcx, item); |
| intravisit::walk_item(self, item); |
| } |
| |
| fn visit_generics(&mut self, generics: &'tcx hir::Generics<'tcx>) { |
| for param in generics.params { |
| match param.kind { |
| hir::GenericParamKind::Lifetime { .. } => {} |
| hir::GenericParamKind::Type { default: Some(_), .. } => { |
| let def_id = self.tcx.hir().local_def_id(param.hir_id); |
| self.tcx.ensure().type_of(def_id); |
| } |
| hir::GenericParamKind::Type { .. } => {} |
| hir::GenericParamKind::Const { default, .. } => { |
| let def_id = self.tcx.hir().local_def_id(param.hir_id); |
| self.tcx.ensure().type_of(def_id); |
| if let Some(default) = default { |
| let default_def_id = self.tcx.hir().local_def_id(default.hir_id); |
| // need to store default and type of default |
| self.tcx.ensure().type_of(default_def_id); |
| self.tcx.ensure().const_param_default(def_id); |
| } |
| } |
| } |
| } |
| intravisit::walk_generics(self, generics); |
| } |
| |
| fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) { |
| if let hir::ExprKind::Closure { .. } = expr.kind { |
| let def_id = self.tcx.hir().local_def_id(expr.hir_id); |
| self.tcx.ensure().generics_of(def_id); |
| // We do not call `type_of` for closures here as that |
| // depends on typecheck and would therefore hide |
| // any further errors in case one typeck fails. |
| } |
| intravisit::walk_expr(self, expr); |
| } |
| |
| fn visit_trait_item(&mut self, trait_item: &'tcx hir::TraitItem<'tcx>) { |
| convert_trait_item(self.tcx, trait_item.trait_item_id()); |
| intravisit::walk_trait_item(self, trait_item); |
| } |
| |
| fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem<'tcx>) { |
| convert_impl_item(self.tcx, impl_item.impl_item_id()); |
| intravisit::walk_impl_item(self, impl_item); |
| } |
| } |
| |
| /////////////////////////////////////////////////////////////////////////// |
| // Utility types and common code for the above passes. |
| |
| fn bad_placeholder<'tcx>( |
| tcx: TyCtxt<'tcx>, |
| mut spans: Vec<Span>, |
| kind: &'static str, |
| ) -> DiagnosticBuilder<'tcx, ErrorGuaranteed> { |
| let kind = if kind.ends_with('s') { format!("{}es", kind) } else { format!("{}s", kind) }; |
| |
| spans.sort(); |
| let mut err = struct_span_err!( |
| tcx.sess, |
| spans.clone(), |
| E0121, |
| "the placeholder `_` is not allowed within types on item signatures for {}", |
| kind |
| ); |
| for span in spans { |
| err.span_label(span, "not allowed in type signatures"); |
| } |
| err |
| } |
| |
| impl<'tcx> ItemCtxt<'tcx> { |
| pub fn new(tcx: TyCtxt<'tcx>, item_def_id: DefId) -> ItemCtxt<'tcx> { |
| ItemCtxt { tcx, item_def_id } |
| } |
| |
| pub fn to_ty(&self, ast_ty: &hir::Ty<'_>) -> Ty<'tcx> { |
| <dyn AstConv<'_>>::ast_ty_to_ty(self, ast_ty) |
| } |
| |
| pub fn hir_id(&self) -> hir::HirId { |
| self.tcx.hir().local_def_id_to_hir_id(self.item_def_id.expect_local()) |
| } |
| |
| pub fn node(&self) -> hir::Node<'tcx> { |
| self.tcx.hir().get(self.hir_id()) |
| } |
| } |
| |
| impl<'tcx> AstConv<'tcx> for ItemCtxt<'tcx> { |
| fn tcx(&self) -> TyCtxt<'tcx> { |
| self.tcx |
| } |
| |
| fn item_def_id(&self) -> Option<DefId> { |
| Some(self.item_def_id) |
| } |
| |
| fn get_type_parameter_bounds( |
| &self, |
| span: Span, |
| def_id: DefId, |
| assoc_name: Ident, |
| ) -> ty::GenericPredicates<'tcx> { |
| self.tcx.at(span).type_param_predicates(( |
| self.item_def_id, |
| def_id.expect_local(), |
| assoc_name, |
| )) |
| } |
| |
| fn re_infer(&self, _: Option<&ty::GenericParamDef>, _: Span) -> Option<ty::Region<'tcx>> { |
| None |
| } |
| |
| fn allow_ty_infer(&self) -> bool { |
| false |
| } |
| |
| fn ty_infer(&self, _: Option<&ty::GenericParamDef>, span: Span) -> Ty<'tcx> { |
| self.tcx().ty_error_with_message(span, "bad placeholder type") |
| } |
| |
| 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, |
| _ => r, |
| }); |
| self.tcx().const_error_with_message(ty, span, "bad placeholder constant") |
| } |
| |
| fn projected_ty_from_poly_trait_ref( |
| &self, |
| span: Span, |
| item_def_id: DefId, |
| item_segment: &hir::PathSegment<'_>, |
| 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, |
| span, |
| item_def_id, |
| item_segment, |
| trait_ref.substs, |
| ); |
| self.tcx().mk_projection(item_def_id, item_substs) |
| } 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() |
| } |
| |
| fn convert_item(tcx: TyCtxt<'_>, item_id: hir::ItemId) { |
| let it = tcx.hir().item(item_id); |
| debug!("convert: item {} with id {}", it.ident, it.hir_id()); |
| let def_id = item_id.owner_id.def_id; |
| |
| match it.kind { |
| // These don't define types. |
| hir::ItemKind::ExternCrate(_) |
| | hir::ItemKind::Use(..) |
| | hir::ItemKind::Macro(..) |
| | hir::ItemKind::Mod(_) |
| | hir::ItemKind::GlobalAsm(_) => {} |
| hir::ItemKind::ForeignMod { items, .. } => { |
| for item in items { |
| let item = tcx.hir().foreign_item(item.id); |
| tcx.ensure().generics_of(item.owner_id); |
| tcx.ensure().type_of(item.owner_id); |
| tcx.ensure().predicates_of(item.owner_id); |
| match item.kind { |
| hir::ForeignItemKind::Fn(..) => tcx.ensure().fn_sig(item.owner_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.owner_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.owner_id; |
| tcx.ensure().generics_of(def_id); |
| tcx.ensure().type_of(def_id); |
| tcx.ensure().predicates_of(def_id); |
| let impl_item = tcx.hir().impl_item(impl_item_id); |
| match impl_item.kind { |
| hir::ImplItemKind::Fn(..) => { |
| tcx.ensure().fn_sig(def_id); |
| } |
| hir::ImplItemKind::Type(_) => { |
| // Account for `type T = _;` |
| let mut visitor = HirPlaceholderCollector::default(); |
| visitor.visit_impl_item(impl_item); |
| |
| placeholder_type_error(tcx, None, visitor.0, false, None, "associated type"); |
| } |
| hir::ImplItemKind::Const(..) => {} |
| } |
| } |
| |
| fn convert_variant_ctor(tcx: TyCtxt<'_>, 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) |
| } |
| |
| 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.owner_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 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 infer 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); |
| let item = tcx.hir().expect_item(def_id.expect_local()); |
| match item.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, |
| check_impl_constness(tcx, impl_.constness, ast_trait_ref), |
| ) |
| }), |
| _ => bug!(), |
| } |
| } |
| |
| fn check_impl_constness( |
| tcx: TyCtxt<'_>, |
| constness: hir::Constness, |
| ast_trait_ref: &hir::TraitRef<'_>, |
| ) -> ty::BoundConstness { |
| match constness { |
| hir::Constness::Const => { |
| if let Some(trait_def_id) = ast_trait_ref.trait_def_id() && !tcx.has_attr(trait_def_id, sym::const_trait) { |
| let trait_name = tcx.item_name(trait_def_id).to_string(); |
| tcx.sess.emit_err(errors::ConstImplForNonConstTrait { |
| trait_ref_span: ast_trait_ref.path.span, |
| trait_name, |
| local_trait_span: trait_def_id.as_local().map(|_| tcx.def_span(trait_def_id).shrink_to_lo()), |
| marking: (), |
| adding: (), |
| }); |
| ty::BoundConstness::NotConst |
| } else { |
| ty::BoundConstness::ConstIfConst |
| } |
| }, |
| hir::Constness::NotConst => ty::BoundConstness::NotConst, |
| } |
| } |
| |
| fn impl_polarity(tcx: TyCtxt<'_>, def_id: 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 |
| } |
| |
| 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, 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; |
| } |
| |
| 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_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, |
| "`no_sanitize` will have no effect after inlining", |
| |lint| lint.span_note(inline_span, "inlining requested here"), |
| ) |
| } |
| } |
| } |
| |
| // 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(); |
| } |
| } |
| } |
