| //! "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, Bounds, SizedByDefault}; |
| use crate::check::intrinsic::intrinsic_operation_unsafety; |
| use crate::constrained_generic_params as cgp; |
| use crate::middle::resolve_lifetime as rl; |
| use rustc_ast::ast; |
| use rustc_ast::ast::{Ident, MetaItemKind}; |
| use rustc_attr::{list_contains_name, mark_used, InlineAttr, OptimizeAttr}; |
| use rustc_data_structures::captures::Captures; |
| use rustc_data_structures::fx::{FxHashMap, FxHashSet}; |
| use rustc_errors::{struct_span_err, Applicability}; |
| use rustc_hir as hir; |
| use rustc_hir::def::{CtorKind, DefKind, Res}; |
| use rustc_hir::def_id::{DefId, LOCAL_CRATE}; |
| use rustc_hir::intravisit::{self, NestedVisitorMap, Visitor}; |
| use rustc_hir::weak_lang_items; |
| use rustc_hir::{GenericParamKind, Node, Unsafety}; |
| use rustc_middle::hir::map::blocks::FnLikeNode; |
| use rustc_middle::hir::map::Map; |
| 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::subst::{InternalSubsts, Subst}; |
| use rustc_middle::ty::util::Discr; |
| use rustc_middle::ty::util::IntTypeExt; |
| use rustc_middle::ty::{self, AdtKind, Const, ToPolyTraitRef, Ty, TyCtxt}; |
| use rustc_middle::ty::{ReprOptions, ToPredicate, WithConstness}; |
| use rustc_session::lint; |
| use rustc_session::parse::feature_err; |
| use rustc_span::symbol::{kw, sym, Symbol}; |
| use rustc_span::{Span, DUMMY_SP}; |
| use rustc_target::spec::abi; |
| |
| mod type_of; |
| |
| struct OnlySelfBounds(bool); |
| |
| /////////////////////////////////////////////////////////////////////////// |
| // Main entry point |
| |
| fn collect_mod_item_types(tcx: TyCtxt<'_>, module_def_id: DefId) { |
| tcx.hir().visit_item_likes_in_module( |
| module_def_id, |
| &mut CollectItemTypesVisitor { tcx }.as_deep_visitor(), |
| ); |
| } |
| |
| pub fn provide(providers: &mut Providers<'_>) { |
| *providers = Providers { |
| type_of: type_of::type_of, |
| generics_of, |
| predicates_of, |
| predicates_defined_on, |
| explicit_predicates_of, |
| super_predicates_of, |
| type_param_predicates, |
| trait_def, |
| adt_def, |
| fn_sig, |
| impl_trait_ref, |
| impl_polarity, |
| is_foreign_item, |
| static_mutability, |
| generator_kind, |
| codegen_fn_attrs, |
| collect_mod_item_types, |
| ..*providers |
| }; |
| } |
| |
| /////////////////////////////////////////////////////////////////////////// |
| |
| /// Context specific to some particular item. This is what implements |
| /// `AstConv`. It 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)] |
| crate struct PlaceholderHirTyCollector(crate Vec<Span>); |
| |
| impl<'v> Visitor<'v> for PlaceholderHirTyCollector { |
| type Map = intravisit::ErasedMap<'v>; |
| |
| fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> { |
| NestedVisitorMap::None |
| } |
| 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) |
| } |
| } |
| |
| 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. |
| crate fn placeholder_type_error( |
| tcx: TyCtxt<'tcx>, |
| span: Span, |
| generics: &[hir::GenericParam<'_>], |
| placeholder_types: Vec<Span>, |
| suggest: bool, |
| ) { |
| if placeholder_types.is_empty() { |
| return; |
| } |
| // This is the whitelist of possible parameter names that we might suggest. |
| let possible_names = ["T", "K", "L", "A", "B", "C"]; |
| let used_names = generics |
| .iter() |
| .filter_map(|p| match p.name { |
| hir::ParamName::Plain(ident) => Some(ident.name), |
| _ => None, |
| }) |
| .collect::<Vec<_>>(); |
| |
| let type_name = possible_names |
| .iter() |
| .find(|n| !used_names.contains(&Symbol::intern(n))) |
| .unwrap_or(&"ParamName"); |
| |
| let mut sugg: Vec<_> = |
| placeholder_types.iter().map(|sp| (*sp, (*type_name).to_string())).collect(); |
| if generics.is_empty() { |
| sugg.push((span, format!("<{}>", type_name))); |
| } else if let Some(arg) = generics.iter().find(|arg| match arg.name { |
| hir::ParamName::Plain(Ident { name: kw::Underscore, .. }) => true, |
| _ => false, |
| }) { |
| // 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 { |
| let last = generics.iter().last().unwrap(); |
| sugg.push(( |
| // Account for bounds, we want `fn foo<T: E, K>(_: K)` not `fn foo<T, K: E>(_: K)`. |
| last.bounds_span().unwrap_or(last.span).shrink_to_hi(), |
| format!(", {}", type_name), |
| )); |
| } |
| let mut err = bad_placeholder_type(tcx, placeholder_types); |
| if suggest { |
| err.multipart_suggestion( |
| "use type parameters instead", |
| sugg, |
| Applicability::HasPlaceholders, |
| ); |
| } |
| err.emit(); |
| } |
| |
| fn reject_placeholder_type_signatures_in_item(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 { 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 = PlaceholderHirTyCollector::default(); |
| visitor.visit_item(item); |
| |
| placeholder_type_error(tcx, generics.span, &generics.params[..], visitor.0, suggest); |
| } |
| |
| impl Visitor<'tcx> for CollectItemTypesVisitor<'tcx> { |
| type Map = Map<'tcx>; |
| |
| fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> { |
| NestedVisitorMap::OnlyBodies(self.tcx.hir()) |
| } |
| |
| fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) { |
| convert_item(self.tcx, item.hir_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.type_of(def_id); |
| } |
| hir::GenericParamKind::Type { .. } => {} |
| hir::GenericParamKind::Const { .. } => { |
| let def_id = self.tcx.hir().local_def_id(param.hir_id); |
| self.tcx.type_of(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.generics_of(def_id); |
| self.tcx.type_of(def_id); |
| } |
| intravisit::walk_expr(self, expr); |
| } |
| |
| fn visit_trait_item(&mut self, trait_item: &'tcx hir::TraitItem<'tcx>) { |
| convert_trait_item(self.tcx, trait_item.hir_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.hir_id); |
| intravisit::walk_impl_item(self, impl_item); |
| } |
| } |
| |
| /////////////////////////////////////////////////////////////////////////// |
| // Utility types and common code for the above passes. |
| |
| fn bad_placeholder_type( |
| tcx: TyCtxt<'tcx>, |
| mut spans: Vec<Span>, |
| ) -> rustc_errors::DiagnosticBuilder<'tcx> { |
| spans.sort(); |
| let mut err = struct_span_err!( |
| tcx.sess, |
| spans.clone(), |
| E0121, |
| "the type placeholder `_` is not allowed within types on item signatures", |
| ); |
| for span in spans { |
| err.span_label(span, "not allowed in type signatures"); |
| } |
| err |
| } |
| |
| impl 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: &'tcx hir::Ty<'tcx>) -> Ty<'tcx> { |
| AstConv::ast_ty_to_ty(self, ast_ty) |
| } |
| |
| pub fn hir_id(&self) -> hir::HirId { |
| self.tcx |
| .hir() |
| .as_local_hir_id(self.item_def_id) |
| .expect("Non-local call to local provider is_const_fn") |
| } |
| |
| pub fn node(&self) -> hir::Node<'tcx> { |
| self.tcx.hir().get(self.hir_id()) |
| } |
| } |
| |
| impl 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 default_constness_for_trait_bounds(&self) -> hir::Constness { |
| if let Some(fn_like) = FnLikeNode::from_node(self.node()) { |
| fn_like.constness() |
| } else { |
| hir::Constness::NotConst |
| } |
| } |
| |
| fn get_type_parameter_bounds(&self, span: Span, def_id: DefId) -> ty::GenericPredicates<'tcx> { |
| self.tcx.at(span).type_param_predicates((self.item_def_id, def_id)) |
| } |
| |
| 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().sess.delay_span_bug(span, "bad placeholder type"); |
| self.tcx().types.err |
| } |
| |
| fn ct_infer( |
| &self, |
| _: Ty<'tcx>, |
| _: Option<&ty::GenericParamDef>, |
| span: Span, |
| ) -> &'tcx Const<'tcx> { |
| bad_placeholder_type(self.tcx(), vec![span]).emit(); |
| |
| self.tcx().consts.err |
| } |
| |
| 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, |
| self.tcx, |
| 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 extract an associated type from a higher-ranked trait bound \ |
| in this context" |
| ); |
| |
| 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())); |
| 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, |
| format!( |
| "{}::{}", |
| // Replace the existing lifetimes with a new named lifetime. |
| self.tcx |
| .replace_late_bound_regions(&poly_trait_ref, |_| { |
| self.tcx.mk_region(ty::ReEarlyBound( |
| ty::EarlyBoundRegion { |
| def_id: item_def_id, |
| index: 0, |
| name: Symbol::intern(<_name), |
| }, |
| )) |
| }) |
| .0, |
| item_segment.ident |
| ), |
| ), |
| ]; |
| err.multipart_suggestion( |
| "use a fully qualified path with explicit lifetimes", |
| suggestions, |
| Applicability::MaybeIncorrect, |
| ); |
| } |
| _ => {} |
| } |
| } |
| hir::Node::Item(hir::Item { kind: hir::ItemKind::Struct(..), .. }) |
| | hir::Node::Item(hir::Item { kind: hir::ItemKind::Enum(..), .. }) |
| | hir::Node::Item(hir::Item { kind: hir::ItemKind::Union(..), .. }) => {} |
| hir::Node::Item(_) |
| | hir::Node::ForeignItem(_) |
| | hir::Node::TraitItem(_) |
| | hir::Node::ImplItem(_) => { |
| err.span_suggestion( |
| span, |
| "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(), |
| item_segment.ident |
| ), |
| Applicability::MaybeIncorrect, |
| ); |
| } |
| _ => {} |
| } |
| err.emit(); |
| self.tcx().types.err |
| } |
| } |
| |
| 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::BoundRegion::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`. |
| fn type_param_predicates( |
| tcx: TyCtxt<'_>, |
| (item_def_id, def_id): (DefId, DefId), |
| ) -> 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().as_local_hir_id(def_id).unwrap(); |
| let param_owner = tcx.hir().ty_param_owner(param_id); |
| let param_owner_def_id = tcx.hir().local_def_id(param_owner); |
| let generics = tcx.generics_of(param_owner_def_id); |
| let index = generics.param_def_id_to_index[&def_id]; |
| let ty = tcx.mk_ty_param(index, tcx.hir().ty_param_name(param_id)); |
| |
| // Don't look for bounds where the type parameter isn't in scope. |
| let parent = |
| if item_def_id == param_owner_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) |
| }) |
| .unwrap_or_default(); |
| let mut extend = None; |
| |
| let item_hir_id = tcx.hir().as_local_hir_id(item_def_id).unwrap(); |
| 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 { ref generics, .. } |
| | ItemKind::TyAlias(_, ref generics) |
| | ItemKind::OpaqueTy(OpaqueTy { ref generics, impl_trait_fn: None, .. }) |
| | 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(), 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)) |
| .into_iter() |
| .filter(|(predicate, _)| match predicate { |
| ty::Predicate::Trait(ref data, _) => data.skip_binder().self_ty().is_param(index), |
| _ => false, |
| }), |
| ); |
| result.predicates = |
| tcx.arena.alloc_from_iter(result.predicates.iter().copied().chain(extra_predicates)); |
| result |
| } |
| |
| impl 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. |
| fn type_parameter_bounds_in_generics( |
| &self, |
| ast_generics: &'tcx hir::Generics<'tcx>, |
| param_id: hir::HirId, |
| ty: Ty<'tcx>, |
| only_self_bounds: OnlySelfBounds, |
| ) -> Vec<(ty::Predicate<'tcx>, Span)> { |
| let constness = self.default_constness_for_trait_bounds(); |
| let from_ty_params = ast_generics |
| .params |
| .iter() |
| .filter_map(|param| match param.kind { |
| GenericParamKind::Type { .. } if param.hir_id == param_id => Some(¶m.bounds), |
| _ => None, |
| }) |
| .flat_map(|bounds| bounds.iter()) |
| .flat_map(|b| predicates_from_bound(self, ty, b, constness)); |
| |
| let from_where_clauses = ast_generics |
| .where_clause |
| .predicates |
| .iter() |
| .filter_map(|wp| match *wp { |
| hir::WherePredicate::BoundPredicate(ref bp) => Some(bp), |
| _ => None, |
| }) |
| .flat_map(|bp| { |
| let bt = if is_param(self.tcx, &bp.bounded_ty, param_id) { |
| Some(ty) |
| } else if !only_self_bounds.0 { |
| Some(self.to_ty(&bp.bounded_ty)) |
| } else { |
| None |
| }; |
| bp.bounds.iter().filter_map(move |b| bt.map(|bt| (bt, b))) |
| }) |
| .flat_map(|(bt, b)| predicates_from_bound(self, bt, b, constness)); |
| |
| from_ty_params.chain(from_where_clauses).collect() |
| } |
| } |
| |
| /// Tests whether this is the AST for a reference to the type |
| /// parameter with ID `param_id`. We use this so as to avoid running |
| /// `ast_ty_to_ty`, because we want to avoid triggering an all-out |
| /// conversion of the type to avoid inducing unnecessary cycles. |
| fn is_param(tcx: TyCtxt<'_>, ast_ty: &hir::Ty<'_>, param_id: hir::HirId) -> bool { |
| if let hir::TyKind::Path(hir::QPath::Resolved(None, ref path)) = ast_ty.kind { |
| match path.res { |
| Res::SelfTy(Some(def_id), None) | Res::Def(DefKind::TyParam, def_id) => { |
| def_id == tcx.hir().local_def_id(param_id) |
| } |
| _ => false, |
| } |
| } else { |
| false |
| } |
| } |
| |
| fn convert_item(tcx: TyCtxt<'_>, item_id: hir::HirId) { |
| let it = tcx.hir().expect_item(item_id); |
| debug!("convert: item {} with id {}", it.ident, it.hir_id); |
| let def_id = tcx.hir().local_def_id(item_id); |
| match it.kind { |
| // These don't define types. |
| hir::ItemKind::ExternCrate(_) |
| | hir::ItemKind::Use(..) |
| | hir::ItemKind::Mod(_) |
| | hir::ItemKind::GlobalAsm(_) => {} |
| hir::ItemKind::ForeignMod(ref foreign_mod) => { |
| for item in foreign_mod.items { |
| let def_id = tcx.hir().local_def_id(item.hir_id); |
| tcx.generics_of(def_id); |
| tcx.type_of(def_id); |
| tcx.predicates_of(def_id); |
| if let hir::ForeignItemKind::Fn(..) = item.kind { |
| tcx.fn_sig(def_id); |
| } |
| } |
| } |
| hir::ItemKind::Enum(ref enum_definition, _) => { |
| tcx.generics_of(def_id); |
| tcx.type_of(def_id); |
| tcx.predicates_of(def_id); |
| convert_enum_variant_types(tcx, def_id, &enum_definition.variants); |
| } |
| hir::ItemKind::Impl { .. } => { |
| tcx.generics_of(def_id); |
| tcx.type_of(def_id); |
| tcx.impl_trait_ref(def_id); |
| tcx.predicates_of(def_id); |
| } |
| hir::ItemKind::Trait(..) => { |
| tcx.generics_of(def_id); |
| tcx.trait_def(def_id); |
| tcx.at(it.span).super_predicates_of(def_id); |
| tcx.predicates_of(def_id); |
| } |
| hir::ItemKind::TraitAlias(..) => { |
| tcx.generics_of(def_id); |
| tcx.at(it.span).super_predicates_of(def_id); |
| tcx.predicates_of(def_id); |
| } |
| hir::ItemKind::Struct(ref struct_def, _) | hir::ItemKind::Union(ref struct_def, _) => { |
| tcx.generics_of(def_id); |
| tcx.type_of(def_id); |
| tcx.predicates_of(def_id); |
| |
| for f in struct_def.fields() { |
| let def_id = tcx.hir().local_def_id(f.hir_id); |
| tcx.generics_of(def_id); |
| tcx.type_of(def_id); |
| tcx.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 { impl_trait_fn: Some(_), .. }) => {} |
| |
| hir::ItemKind::OpaqueTy(..) |
| | hir::ItemKind::TyAlias(..) |
| | hir::ItemKind::Static(..) |
| | hir::ItemKind::Const(..) |
| | hir::ItemKind::Fn(..) => { |
| tcx.generics_of(def_id); |
| tcx.type_of(def_id); |
| tcx.predicates_of(def_id); |
| if let hir::ItemKind::Fn(..) = it.kind { |
| tcx.fn_sig(def_id); |
| } |
| } |
| } |
| } |
| |
| fn convert_trait_item(tcx: TyCtxt<'_>, trait_item_id: hir::HirId) { |
| let trait_item = tcx.hir().expect_trait_item(trait_item_id); |
| let def_id = tcx.hir().local_def_id(trait_item.hir_id); |
| tcx.generics_of(def_id); |
| |
| match trait_item.kind { |
| hir::TraitItemKind::Fn(..) => { |
| tcx.type_of(def_id); |
| tcx.fn_sig(def_id); |
| } |
| |
| hir::TraitItemKind::Const(.., Some(_)) => { |
| tcx.type_of(def_id); |
| } |
| |
| hir::TraitItemKind::Const(..) | hir::TraitItemKind::Type(_, Some(_)) => { |
| tcx.type_of(def_id); |
| // Account for `const C: _;` and `type T = _;`. |
| let mut visitor = PlaceholderHirTyCollector::default(); |
| visitor.visit_trait_item(trait_item); |
| placeholder_type_error(tcx, DUMMY_SP, &[], visitor.0, false); |
| } |
| |
| hir::TraitItemKind::Type(_, None) => {} |
| }; |
| |
| tcx.predicates_of(def_id); |
| } |
| |
| fn convert_impl_item(tcx: TyCtxt<'_>, impl_item_id: hir::HirId) { |
| let def_id = tcx.hir().local_def_id(impl_item_id); |
| tcx.generics_of(def_id); |
| tcx.type_of(def_id); |
| tcx.predicates_of(def_id); |
| let impl_item = tcx.hir().expect_impl_item(impl_item_id); |
| match impl_item.kind { |
| hir::ImplItemKind::Fn(..) => { |
| tcx.fn_sig(def_id); |
| } |
| hir::ImplItemKind::TyAlias(_) | hir::ImplItemKind::OpaqueTy(_) => { |
| // Account for `type T = _;` |
| let mut visitor = PlaceholderHirTyCollector::default(); |
| visitor.visit_impl_item(impl_item); |
| placeholder_type_error(tcx, DUMMY_SP, &[], visitor.0, false); |
| } |
| hir::ImplItemKind::Const(..) => {} |
| } |
| } |
| |
| fn convert_variant_ctor(tcx: TyCtxt<'_>, ctor_id: hir::HirId) { |
| let def_id = tcx.hir().local_def_id(ctor_id); |
| tcx.generics_of(def_id); |
| tcx.type_of(def_id); |
| tcx.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) |
| } 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.generics_of(def_id); |
| tcx.type_of(def_id); |
| tcx.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<DefId>, |
| ctor_did: Option<DefId>, |
| ident: Ident, |
| discr: ty::VariantDiscr, |
| def: &hir::VariantData<'_>, |
| adt_kind: ty::AdtKind, |
| parent_did: DefId, |
| ) -> ty::VariantDef { |
| let mut seen_fields: FxHashMap<ast::Ident, Span> = Default::default(); |
| let hir_id = tcx.hir().as_local_hir_id(variant_did.unwrap_or(parent_did)).unwrap(); |
| 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 { |
| struct_span_err!( |
| tcx.sess, |
| f.span, |
| E0124, |
| "field `{}` is already declared", |
| f.ident |
| ) |
| .span_label(f.span, "field already declared") |
| .span_label(prev_span, format!("`{}` first declared here", f.ident)) |
| .emit(); |
| } else { |
| seen_fields.insert(f.ident.normalize_to_macros_2_0(), f.span); |
| } |
| |
| ty::FieldDef { |
| did: fid, |
| ident: f.ident, |
| vis: ty::Visibility::from_hir(&f.vis, hir_id, tcx), |
| } |
| }) |
| .collect(); |
| let recovered = match def { |
| hir::VariantData::Struct(_, r) => *r, |
| _ => false, |
| }; |
| ty::VariantDef::new( |
| tcx, |
| ident, |
| variant_did, |
| ctor_did, |
| discr, |
| fields, |
| CtorKind::from_hir(def), |
| adt_kind, |
| parent_did, |
| recovered, |
| ) |
| } |
| |
| fn adt_def(tcx: TyCtxt<'_>, def_id: DefId) -> &ty::AdtDef { |
| use rustc_hir::*; |
| |
| let hir_id = tcx.hir().as_local_hir_id(def_id).unwrap(); |
| let item = match tcx.hir().get(hir_id) { |
| Node::Item(item) => item, |
| _ => bug!(), |
| }; |
| |
| let repr = ReprOptions::new(tcx, 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)) |
| } 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; |
| 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, 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); |
| let trait_hir_id = tcx.hir().as_local_hir_id(trait_def_id).unwrap(); |
| |
| let item = match tcx.hir().get(trait_hir_id) { |
| Node::Item(item) => item, |
| _ => 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 = |
| AstConv::compute_bounds(&icx, self_param_ty, bounds, SizedByDefault::No, item.span); |
| |
| 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), |
| ); |
| |
| // Combine the two lists to form the complete set of superbounds: |
| let superbounds = &*tcx.arena.alloc_from_iter(superbounds1.into_iter().chain(superbounds2)); |
| |
| // 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::Predicate::Trait(bound, _) = pred { |
| tcx.at(span).super_predicates_of(bound.def_id()); |
| } |
| } |
| |
| ty::GenericPredicates { parent: None, predicates: superbounds } |
| } |
| |
| fn trait_def(tcx: TyCtxt<'_>, def_id: DefId) -> &ty::TraitDef { |
| let hir_id = tcx.hir().as_local_hir_id(def_id).unwrap(); |
| let item = tcx.hir().expect_item(hir_id); |
| |
| let (is_auto, unsafety) = match item.kind { |
| hir::ItemKind::Trait(is_auto, unsafety, ..) => (is_auto == hir::IsAuto::Yes, unsafety), |
| 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 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 def_path_hash = tcx.def_path_hash(def_id); |
| let def = ty::TraitDef::new( |
| def_id, |
| unsafety, |
| paren_sugar, |
| is_auto, |
| is_marker, |
| spec_kind, |
| def_path_hash, |
| ); |
| tcx.arena.alloc(def) |
| } |
| |
| 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 Visitor<'tcx> for LateBoundRegionsDetector<'tcx> { |
| type Map = intravisit::ErasedMap<'tcx>; |
| |
| fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> { |
| NestedVisitorMap::None |
| } |
| |
| 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>, |
| m: hir::TraitBoundModifier, |
| ) { |
| if self.has_late_bound_regions.is_some() { |
| return; |
| } |
| self.outer_index.shift_in(1); |
| intravisit::walk_poly_trait_ref(self, tr, m); |
| 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) | Some(rl::Region::EarlyBound(..)) => {} |
| Some(rl::Region::LateBound(debruijn, _, _)) |
| | Some(rl::Region::LateBoundAnon(debruijn, _)) |
| if debruijn < self.outer_index => {} |
| Some(rl::Region::LateBound(..)) |
| | Some(rl::Region::LateBoundAnon(..)) |
| | Some(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(ref 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, |
| } |
| } |
| |
| fn generics_of(tcx: TyCtxt<'_>, def_id: DefId) -> &ty::Generics { |
| use rustc_hir::*; |
| |
| let hir_id = tcx.hir().as_local_hir_id(def_id).unwrap(); |
| |
| 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(tcx.hir().local_def_id(parent_id)) |
| } |
| // FIXME(#43408) enable this always when we get lazy normalization. |
| Node::AnonConst(_) => { |
| // HACK(eddyb) this provides the correct generics when |
| // `feature(const_generics)` is enabled, so that const expressions |
| // used with const generics, e.g. `Foo<{N+1}>`, can work at all. |
| if tcx.features().const_generics { |
| let parent_id = tcx.hir().get_parent_item(hir_id); |
| Some(tcx.hir().local_def_id(parent_id)) |
| } else { |
| None |
| } |
| } |
| Node::Expr(&hir::Expr { kind: hir::ExprKind::Closure(..), .. }) => { |
| Some(tcx.closure_base_def_id(def_id)) |
| } |
| Node::Item(item) => match item.kind { |
| ItemKind::OpaqueTy(hir::OpaqueTy { impl_trait_fn, .. }) => { |
| impl_trait_fn.or_else(|| { |
| let parent_id = tcx.hir().get_parent_item(hir_id); |
| if parent_id != hir_id && parent_id != CRATE_HIR_ID { |
| debug!("generics_of: parent of opaque ty {:?} is {:?}", def_id, parent_id); |
| // If this 'impl Trait' is nested inside another 'impl Trait' |
| // (e.g. `impl Foo<MyType = impl Bar<A>>`), we need to use the 'parent' |
| // 'impl Trait' for its generic parameters, since we can reference them |
| // from the 'child' 'impl Trait' |
| if let Node::Item(hir::Item { kind: ItemKind::OpaqueTy(..), .. }) = |
| tcx.hir().get(parent_id) |
| { |
| Some(tcx.hir().local_def_id(parent_id)) |
| } else { |
| None |
| } |
| } else { |
| None |
| } |
| }) |
| } |
| _ => None, |
| }, |
| _ => None, |
| }; |
| |
| let mut opt_self = None; |
| let mut allow_defaults = false; |
| |
| let no_generics = hir::Generics::empty(); |
| let ast_generics = match node { |
| Node::TraitItem(item) => &item.generics, |
| |
| Node::ImplItem(item) => &item.generics, |
| |
| Node::Item(item) => { |
| match item.kind { |
| ItemKind::Fn(.., ref generics, _) | ItemKind::Impl { ref generics, .. } => generics, |
| |
| ItemKind::TyAlias(_, ref generics) |
| | ItemKind::Enum(_, ref generics) |
| | ItemKind::Struct(_, ref generics) |
| | ItemKind::OpaqueTy(hir::OpaqueTy { ref generics, .. }) |
| | ItemKind::Union(_, ref generics) => { |
| allow_defaults = true; |
| generics |
| } |
| |
| ItemKind::Trait(_, _, ref generics, ..) |
| | ItemKind::TraitAlias(ref generics, ..) => { |
| // 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 param_id = item.hir_id; |
| |
| opt_self = Some(ty::GenericParamDef { |
| index: 0, |
| name: kw::SelfUpper, |
| def_id: tcx.hir().local_def_id(param_id), |
| pure_wrt_drop: false, |
| kind: ty::GenericParamDefKind::Type { |
| has_default: false, |
| object_lifetime_default: rl::Set1::Empty, |
| synthetic: None, |
| }, |
| }); |
| |
| allow_defaults = true; |
| 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 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_eq!(has_self, false); |
| parent_has_self = generics.has_self; |
| own_start = generics.count() as u32; |
| generics.parent_count + generics.params.len() |
| }); |
| |
| let mut params: Vec<_> = opt_self.into_iter().collect(); |
| |
| 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), |
| pure_wrt_drop: param.pure_wrt_drop, |
| kind: ty::GenericParamDefKind::Lifetime, |
| })); |
| |
| let object_lifetime_defaults = tcx.object_lifetime_defaults(hir_id); |
| |
| // 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; |
| |
| // FIXME(const_generics): a few places in the compiler expect generic params |
| // to be in the order lifetimes, then type params, then const params. |
| // |
| // To prevent internal errors in case const parameters are supplied before |
| // type parameters we first add all type params, then all const params. |
| params.extend(ast_generics.params.iter().filter_map(|param| { |
| if let GenericParamKind::Type { ref default, synthetic, .. } = param.kind { |
| if !allow_defaults && default.is_some() { |
| if !tcx.features().default_type_parameter_fallback { |
| tcx.struct_span_lint_hir( |
| lint::builtin::INVALID_TYPE_PARAM_DEFAULT, |
| param.hir_id, |
| param.span, |
| |lint| { |
| lint.build( |
| "defaults for type parameters are only allowed in \ |
| `struct`, `enum`, `type`, or `trait` definitions.", |
| ) |
| .emit(); |
| }, |
| ); |
| } |
| } |
| |
| let kind = ty::GenericParamDefKind::Type { |
| has_default: default.is_some(), |
| object_lifetime_default: object_lifetime_defaults |
| .as_ref() |
| .map_or(rl::Set1::Empty, |o| o[i]), |
| 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), |
| pure_wrt_drop: param.pure_wrt_drop, |
| kind, |
| }; |
| i += 1; |
| Some(param_def) |
| } else { |
| None |
| } |
| })); |
| |
| params.extend(ast_generics.params.iter().filter_map(|param| { |
| if let GenericParamKind::Const { .. } = param.kind { |
| 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), |
| pure_wrt_drop: param.pure_wrt_drop, |
| kind: ty::GenericParamDefKind::Const, |
| }; |
| i += 1; |
| Some(param_def) |
| } else { |
| None |
| } |
| })); |
| |
| // 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(.., 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, |
| object_lifetime_default: rl::Set1::Empty, |
| synthetic: None, |
| }, |
| })); |
| } |
| |
| let param_def_id_to_index = params.iter().map(|param| (param.def_id, param.index)).collect(); |
| |
| tcx.arena.alloc(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() |
| .filter_map(|arg| match arg { |
| hir::GenericArg::Type(ty) => Some(ty), |
| _ => None, |
| }) |
| .any(is_suggestable_infer_ty) |
| } |
| |
| /// 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 { |
| use hir::TyKind::*; |
| match &ty.kind { |
| Infer => true, |
| Slice(ty) | Array(ty, _) => is_suggestable_infer_ty(ty), |
| Tup(tys) => tys.iter().any(is_suggestable_infer_ty), |
| Ptr(mut_ty) | Rptr(_, mut_ty) => is_suggestable_infer_ty(mut_ty.ty), |
| Def(_, generic_args) => are_suggestable_generic_args(generic_args), |
| Path(hir::QPath::TypeRelative(ty, segment)) => { |
| is_suggestable_infer_ty(ty) || are_suggestable_generic_args(segment.generic_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.generic_args().args)) |
| } |
| _ => false, |
| } |
| } |
| |
| pub fn get_infer_ret_ty(output: &'hir hir::FnRetTy<'hir>) -> Option<&'hir hir::Ty<'hir>> { |
| if let hir::FnRetTy::Return(ref ty) = output { |
| if is_suggestable_infer_ty(ty) { |
| return Some(&**ty); |
| } |
| } |
| None |
| } |
| |
| fn fn_sig(tcx: TyCtxt<'_>, def_id: DefId) -> ty::PolyFnSig<'_> { |
| use rustc_hir::Node::*; |
| use rustc_hir::*; |
| |
| let hir_id = tcx.hir().as_local_hir_id(def_id).unwrap(); |
| |
| let icx = ItemCtxt::new(tcx, def_id); |
| |
| match tcx.hir().get(hir_id) { |
| TraitItem(hir::TraitItem { |
| kind: TraitItemKind::Fn(sig, TraitFn::Provided(_)), |
| ident, |
| generics, |
| .. |
| }) |
| | ImplItem(hir::ImplItem { kind: ImplItemKind::Fn(sig, _), ident, generics, .. }) |
| | Item(hir::Item { kind: ItemKind::Fn(sig, generics, _), ident, .. }) => { |
| match get_infer_ret_ty(&sig.decl.output) { |
| Some(ty) => { |
| let fn_sig = tcx.typeck_tables_of(def_id).liberated_fn_sigs()[hir_id]; |
| let mut visitor = PlaceholderHirTyCollector::default(); |
| visitor.visit_ty(ty); |
| let mut diag = bad_placeholder_type(tcx, visitor.0); |
| let ret_ty = fn_sig.output(); |
| if ret_ty != tcx.types.err { |
| diag.span_suggestion( |
| ty.span, |
| "replace with the correct return type", |
| ret_ty.to_string(), |
| Applicability::MaybeIncorrect, |
| ); |
| } |
| diag.emit(); |
| ty::Binder::bind(fn_sig) |
| } |
| None => AstConv::ty_of_fn( |
| &icx, |
| sig.header.unsafety, |
| sig.header.abi, |
| &sig.decl, |
| &generics, |
| Some(ident.span), |
| ), |
| } |
| } |
| |
| TraitItem(hir::TraitItem { |
| kind: TraitItemKind::Fn(FnSig { header, decl }, _), |
| ident, |
| generics, |
| .. |
| }) => { |
| AstConv::ty_of_fn(&icx, header.unsafety, header.abi, decl, &generics, Some(ident.span)) |
| } |
| |
| ForeignItem(&hir::ForeignItem { |
| kind: ForeignItemKind::Fn(ref fn_decl, _, _), |
| ident, |
| .. |
| }) => { |
| let abi = tcx.hir().get_foreign_abi(hir_id); |
| compute_sig_of_foreign_fn_decl(tcx, def_id, fn_decl, abi, ident) |
| } |
| |
| Ctor(data) | Variant(hir::Variant { data, .. }) if data.ctor_hir_id().is_some() => { |
| let ty = tcx.type_of(tcx.hir().get_parent_did(hir_id)); |
| let inputs = |
| data.fields().iter().map(|f| tcx.type_of(tcx.hir().local_def_id(f.hir_id))); |
| ty::Binder::bind(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 impl_trait_ref(tcx: TyCtxt<'_>, def_id: DefId) -> Option<ty::TraitRef<'_>> { |
| let icx = ItemCtxt::new(tcx, def_id); |
| |
| let hir_id = tcx.hir().as_local_hir_id(def_id).unwrap(); |
| match tcx.hir().expect_item(hir_id).kind { |
| hir::ItemKind::Impl { ref of_trait, .. } => of_trait.as_ref().map(|ast_trait_ref| { |
| let selfty = tcx.type_of(def_id); |
| AstConv::instantiate_mono_trait_ref(&icx, ast_trait_ref, selfty) |
| }), |
| _ => bug!(), |
| } |
| } |
| |
| fn impl_polarity(tcx: TyCtxt<'_>, def_id: DefId) -> ty::ImplPolarity { |
| let hir_id = tcx.hir().as_local_hir_id(def_id).unwrap(); |
| let is_rustc_reservation = tcx.has_attr(def_id, sym::rustc_reservation_impl); |
| let item = tcx.hir().expect_item(hir_id); |
| match &item.kind { |
| hir::ItemKind::Impl { polarity: hir::ImplPolarity::Negative(span), of_trait, .. } => { |
| if is_rustc_reservation { |
| let span = span.to(of_trait.as_ref().map(|t| t.path.span).unwrap_or(*span)); |
| tcx.sess.span_err(span, "reservation impls can't be negative"); |
| } |
| ty::ImplPolarity::Negative |
| } |
| hir::ItemKind::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 { |
| polarity: hir::ImplPolarity::Positive, of_trait: Some(_), .. |
| } => { |
| if is_rustc_reservation { |
| ty::ImplPolarity::Reservation |
| } else { |
| ty::ImplPolarity::Positive |
| } |
| } |
| ref 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. |
| fn predicates_defined_on(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericPredicates<'_> { |
| debug!("predicates_defined_on({:?})", def_id); |
| 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. |
| let span = tcx.def_span(def_id); |
| result.predicates = |
| tcx.arena.alloc_from_iter(result.predicates.iter().copied().chain(std::iter::once(( |
| ty::TraitRef::identity(tcx, def_id).without_const().to_predicate(), |
| 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. |
| fn explicit_predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericPredicates<'_> { |
| use rustc_hir::*; |
| |
| debug!("explicit_predicates_of(def_id={:?})", def_id); |
| |
| /// A data structure with unique elements, which preserves order of insertion. |
| /// Preserving the order of insertion is important here so as not to break |
| /// compile-fail UI tests. |
| // FIXME(eddyb) just use `IndexSet` from `indexmap`. |
| struct UniquePredicates<'tcx> { |
| predicates: Vec<(ty::Predicate<'tcx>, Span)>, |
| uniques: FxHashSet<(ty::Predicate<'tcx>, Span)>, |
| } |
| |
| impl<'tcx> UniquePredicates<'tcx> { |
| fn new() -> Self { |
| UniquePredicates { predicates: vec![], uniques: FxHashSet::default() } |
| } |
| |
| fn push(&mut self, value: (ty::Predicate<'tcx>, Span)) { |
| if self.uniques.insert(value) { |
| self.predicates.push(value); |
| } |
| } |
| |
| fn extend<I: IntoIterator<Item = (ty::Predicate<'tcx>, Span)>>(&mut self, iter: I) { |
| for value in iter { |
| self.push(value); |
| } |
| } |
| } |
| |
| let hir_id = tcx.hir().as_local_hir_id(def_id).unwrap(); |
| 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); |
| let constness = icx.default_constness_for_trait_bounds(); |
| |
| const NO_GENERICS: &hir::Generics<'_> = &hir::Generics::empty(); |
| |
| let mut predicates = UniquePredicates::new(); |
| |
| let ast_generics = match node { |
| Node::TraitItem(item) => &item.generics, |
| |
| Node::ImplItem(item) => match item.kind { |
| ImplItemKind::OpaqueTy(ref bounds) => { |
| ty::print::with_no_queries(|| { |
| let substs = InternalSubsts::identity_for_item(tcx, def_id); |
| let opaque_ty = tcx.mk_opaque(def_id, substs); |
| debug!( |
| "explicit_predicates_of({:?}): created opaque type {:?}", |
| def_id, opaque_ty |
| ); |
| |
| // Collect the bounds, i.e., the `A + B + 'c` in `impl A + B + 'c`. |
| let bounds = AstConv::compute_bounds( |
| &icx, |
| opaque_ty, |
| bounds, |
| SizedByDefault::Yes, |
| tcx.def_span(def_id), |
| ); |
| |
| predicates.extend(bounds.predicates(tcx, opaque_ty)); |
| &item.generics |
| }) |
| } |
| _ => &item.generics, |
| }, |
| |
| Node::Item(item) => { |
| match item.kind { |
| ItemKind::Impl { defaultness, ref generics, .. } => { |
| if defaultness.is_default() { |
| is_default_impl_trait = tcx.impl_trait_ref(def_id); |
| } |
| 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, .., items) => { |
| is_trait = Some((ty::TraitRef::identity(tcx, def_id), items)); |
| generics |
| } |
| ItemKind::TraitAlias(ref generics, _) => { |
| is_trait = Some((ty::TraitRef::identity(tcx, def_id), &[])); |
| generics |
| } |
| ItemKind::OpaqueTy(OpaqueTy { |
| ref bounds, |
| impl_trait_fn, |
| ref generics, |
| origin: _, |
| }) => { |
| let bounds_predicates = ty::print::with_no_queries(|| { |
| let substs = InternalSubsts::identity_for_item(tcx, def_id); |
| let opaque_ty = tcx.mk_opaque(def_id, substs); |
| |
| // Collect the bounds, i.e., the `A + B + 'c` in `impl A + B + 'c`. |
| let bounds = AstConv::compute_bounds( |
| &icx, |
| opaque_ty, |
| bounds, |
| SizedByDefault::Yes, |
| tcx.def_span(def_id), |
| ); |
| |
| bounds.predicates(tcx, opaque_ty) |
| }); |
| if impl_trait_fn.is_some() { |
| // opaque types |
| return ty::GenericPredicates { |
| parent: None, |
| predicates: tcx.arena.alloc_from_iter(bounds_predicates), |
| }; |
| } else { |
| // named opaque types |
| predicates.extend(bounds_predicates); |
| 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.push(( |
| trait_ref.to_poly_trait_ref().without_const().to_predicate(), |
| 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; |
| for param in early_bound_lifetimes_from_generics(tcx, ast_generics) { |
| let region = tcx.mk_region(ty::ReEarlyBound(ty::EarlyBoundRegion { |
| def_id: tcx.hir().local_def_id(param.hir_id), |
| index, |
| name: param.name.ident().name, |
| })); |
| index += 1; |
| |
| match param.kind { |
| GenericParamKind::Lifetime { .. } => { |
| param.bounds.iter().for_each(|bound| match bound { |
| hir::GenericBound::Outlives(lt) => { |
| let bound = AstConv::ast_region_to_region(&icx, <, None); |
| let outlives = ty::Binder::bind(ty::OutlivesPredicate(region, bound)); |
| predicates.push((outlives.to_predicate(), lt.span)); |
| } |
| _ => bug!(), |
| }); |
| } |
| _ => bug!(), |
| } |
| } |
| |
| // Collect the predicates that were written inline by the user on each |
| // type parameter (e.g., `<T: Foo>`). |
| for param in ast_generics.params { |
| if let GenericParamKind::Type { .. } = param.kind { |
| let name = param.name.ident().name; |
| let param_ty = ty::ParamTy::new(index, name).to_ty(tcx); |
| index += 1; |
| |
| let sized = SizedByDefault::Yes; |
| let bounds = AstConv::compute_bounds(&icx, param_ty, ¶m.bounds, sized, param.span); |
| predicates.extend(bounds.predicates(tcx, param_ty)); |
| } |
| } |
| |
| // Add in the bounds that appear in the where-clause. |
| let where_clause = &ast_generics.where_clause; |
| for predicate in where_clause.predicates { |
| match predicate { |
| &hir::WherePredicate::BoundPredicate(ref bound_pred) => { |
| let ty = icx.to_ty(&bound_pred.bounded_ty); |
| |
| // 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 re_root_empty = tcx.lifetimes.re_root_empty; |
| let predicate = ty::OutlivesPredicate(ty, re_root_empty); |
| predicates.push(( |
| ty::Predicate::TypeOutlives(ty::Binder::dummy(predicate)), |
| span, |
| )); |
| } |
| } |
| |
| for bound in bound_pred.bounds.iter() { |
| match bound { |
| &hir::GenericBound::Trait(ref poly_trait_ref, modifier) => { |
| let constness = match modifier { |
| hir::TraitBoundModifier::MaybeConst => hir::Constness::NotConst, |
| hir::TraitBoundModifier::None => constness, |
| hir::TraitBoundModifier::Maybe => bug!("this wasn't handled"), |
| }; |
| |
| let mut bounds = Bounds::default(); |
| let _ = AstConv::instantiate_poly_trait_ref( |
| &icx, |
| poly_trait_ref, |
| constness, |
| ty, |
| &mut bounds, |
| ); |
| predicates.extend(bounds.predicates(tcx, ty)); |
| } |
| |
| &hir::GenericBound::Outlives(ref lifetime) => { |
| let region = AstConv::ast_region_to_region(&icx, lifetime, None); |
| let pred = ty::Binder::bind(ty::OutlivesPredicate(ty, region)); |
| predicates.push((ty::Predicate::TypeOutlives(pred), lifetime.span)) |
| } |
| } |
| } |
| } |
| |
| &hir::WherePredicate::RegionPredicate(ref region_pred) => { |
| let r1 = 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) => { |
| (AstConv::ast_region_to_region(&icx, lt, None), lt.span) |
| } |
| _ => bug!(), |
| }; |
| let pred = ty::Binder::bind(ty::OutlivesPredicate(r1, r2)); |
| |
| (ty::Predicate::RegionOutlives(pred), span) |
| })) |
| } |
| |
| &hir::WherePredicate::EqPredicate(..) => { |
| // FIXME(#20041) |
| } |
| } |
| } |
| |
| // Add predicates from associated type bounds. |
| if let Some((self_trait_ref, trait_items)) = is_trait { |
| predicates.extend(trait_items.iter().flat_map(|trait_item_ref| { |
| associated_item_predicates(tcx, def_id, self_trait_ref, trait_item_ref) |
| })) |
| } |
| |
| let mut predicates = predicates.predicates; |
| |
| // 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), |
| ); |
| } |
| |
| let result = ty::GenericPredicates { |
| parent: generics.parent, |
| predicates: tcx.arena.alloc_from_iter(predicates), |
| }; |
| debug!("explicit_predicates_of(def_id={:?}) = {:?}", def_id, result); |
| result |
| } |
| |
| fn associated_item_predicates( |
| tcx: TyCtxt<'tcx>, |
| def_id: DefId, |
| self_trait_ref: ty::TraitRef<'tcx>, |
| trait_item_ref: &hir::TraitItemRef, |
| ) -> Vec<(ty::Predicate<'tcx>, Span)> { |
| let trait_item = tcx.hir().trait_item(trait_item_ref.id); |
| let item_def_id = tcx.hir().local_def_id(trait_item_ref.id.hir_id); |
| let bounds = match trait_item.kind { |
| hir::TraitItemKind::Type(ref bounds, _) => bounds, |
| _ => return Vec::new(), |
| }; |
| |
| let is_gat = !tcx.generics_of(item_def_id).params.is_empty(); |
| |
| let mut had_error = false; |
| |
| let mut unimplemented_error = |arg_kind: &str| { |
| if !had_error { |
| tcx.sess |
| .struct_span_err( |
| trait_item.span, |
| &format!("{}-generic associated types are not yet implemented", arg_kind), |
| ) |
| .note( |
| "for more information, see issue #44265 \ |
| <https://github.com/rust-lang/rust/issues/44265> for more information", |
| ) |
| .emit(); |
| had_error = true; |
| } |
| }; |
| |
| let mk_bound_param = |param: &ty::GenericParamDef, _: &_| { |
| match param.kind { |
| ty::GenericParamDefKind::Lifetime => tcx |
| .mk_region(ty::RegionKind::ReLateBound( |
| ty::INNERMOST, |
| ty::BoundRegion::BrNamed(param.def_id, param.name), |
| )) |
| .into(), |
| // FIXME(generic_associated_types): Use bound types and constants |
| // once they are handled by the trait system. |
| ty::GenericParamDefKind::Type { .. } => { |
| unimplemented_error("type"); |
| tcx.types.err.into() |
| } |
| ty::GenericParamDefKind::Const => { |
| unimplemented_error("const"); |
| tcx.consts.err.into() |
| } |
| } |
| }; |
| |
| let bound_substs = if is_gat { |
| // Given: |
| // |
| // trait X<'a, B, const C: usize> { |
| // type T<'d, E, const F: usize>: Default; |
| // } |
| // |
| // We need to create predicates on the trait: |
| // |
| // for<'d, E, const F: usize> |
| // <Self as X<'a, B, const C: usize>>::T<'d, E, const F: usize>: Sized + Default |
| // |
| // We substitute escaping bound parameters for the generic |
| // arguments to the associated type which are then bound by |
| // the `Binder` around the the predicate. |
| // |
| // FIXME(generic_associated_types): Currently only lifetimes are handled. |
| self_trait_ref.substs.extend_to(tcx, item_def_id, mk_bound_param) |
| } else { |
| self_trait_ref.substs |
| }; |
| |
| let assoc_ty = tcx.mk_projection(tcx.hir().local_def_id(trait_item.hir_id), bound_substs); |
| |
| let bounds = AstConv::compute_bounds( |
| &ItemCtxt::new(tcx, def_id), |
| assoc_ty, |
| bounds, |
| SizedByDefault::Yes, |
| trait_item.span, |
| ); |
| |
| let predicates = bounds.predicates(tcx, assoc_ty); |
| |
| if is_gat { |
| // We use shifts to get the regions that we're substituting to |
| // be bound by the binders in the `Predicate`s rather that |
| // escaping. |
| let shifted_in = ty::fold::shift_vars(tcx, &predicates, 1); |
| let substituted = shifted_in.subst(tcx, bound_substs); |
| ty::fold::shift_out_vars(tcx, &substituted, 1) |
| } else { |
| predicates |
| } |
| } |
| |
| /// 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>, |
| constness: hir::Constness, |
| ) -> Vec<(ty::Predicate<'tcx>, Span)> { |
| match *bound { |
| hir::GenericBound::Trait(ref tr, modifier) => { |
| let constness = match modifier { |
| hir::TraitBoundModifier::Maybe => return vec![], |
| hir::TraitBoundModifier::MaybeConst => hir::Constness::NotConst, |
| hir::TraitBoundModifier::None => constness, |
| }; |
| |
| let mut bounds = Bounds::default(); |
| let _ = astconv.instantiate_poly_trait_ref(tr, constness, param_ty, &mut bounds); |
| bounds.predicates(astconv.tcx(), param_ty) |
| } |
| hir::GenericBound::Outlives(ref lifetime) => { |
| let region = astconv.ast_region_to_region(lifetime, None); |
| let pred = ty::Binder::bind(ty::OutlivesPredicate(param_ty, region)); |
| vec![(ty::Predicate::TypeOutlives(pred), lifetime.span)] |
| } |
| } |
| } |
| |
| fn compute_sig_of_foreign_fn_decl<'tcx>( |
| tcx: TyCtxt<'tcx>, |
| def_id: DefId, |
| decl: &'tcx hir::FnDecl<'tcx>, |
| abi: abi::Abi, |
| ident: Ident, |
| ) -> ty::PolyFnSig<'tcx> { |
| let unsafety = if abi == abi::Abi::RustIntrinsic { |
| intrinsic_operation_unsafety(&tcx.item_name(def_id).as_str()) |
| } else { |
| hir::Unsafety::Unsafe |
| }; |
| let fty = AstConv::ty_of_fn( |
| &ItemCtxt::new(tcx, def_id), |
| unsafety, |
| abi, |
| decl, |
| &hir::Generics::empty(), |
| Some(ident.span), |
| ); |
| |
| // 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(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 decl.inputs.iter().zip(*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 static_mutability(tcx: TyCtxt<'_>, def_id: DefId) -> Option<hir::Mutability> { |
| match tcx.hir().get_if_local(def_id) { |
| Some(Node::Item(&hir::Item { kind: hir::ItemKind::Static(_, mutbl, _), .. })) |
| | Some(Node::ForeignItem(&hir::ForeignItem { |
| kind: hir::ForeignItemKind::Static(_, mutbl), |
| .. |
| })) => Some(mutbl), |
| Some(_) => None, |
| _ => bug!("static_mutability 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(_, _, body_id, _, _), |
| .. |
| })) => tcx.hir().body(body_id).generator_kind(), |
| Some(_) => None, |
| _ => bug!("generator_kind applied to non-local def-id {:?}", def_id), |
| } |
| } |
| |
| fn from_target_feature( |
| tcx: TyCtxt<'_>, |
| id: DefId, |
| attr: &ast::Attribute, |
| whitelist: &FxHashMap<String, Option<Symbol>>, |
| target_features: &mut Vec<Symbol>, |
| ) { |
| let list = match attr.meta_item_list() { |
| Some(list) => list, |
| None => return, |
| }; |
| let bad_item = |span| { |
| let msg = "malformed `target_feature` attribute input"; |
| let code = "enable = \"..\"".to_owned(); |
| 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.check_name(sym::enable) { |
| bad_item(item.span()); |
| continue; |
| } |
| |
| // Must be of the form `enable = "..."` (a string). |
| let value = match item.value_str() { |
| Some(value) => value, |
| None => { |
| bad_item(item.span()); |
| continue; |
| } |
| }; |
| |
| // We allow comma separation to enable multiple features. |
| target_features.extend(value.as_str().split(',').filter_map(|feature| { |
| // Only allow whitelisted features per platform. |
| let feature_gate = match whitelist.get(feature) { |
| Some(g) => g, |
| None => { |
| 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 feature.starts_with('+') { |
| let valid = whitelist.contains_key(&feature[1..]); |
| 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::aarch64_target_feature) => rust_features.aarch64_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::avx512_target_feature) => rust_features.avx512_target_feature, |
| Some(sym::mmx_target_feature) => rust_features.mmx_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::adx_target_feature) => rust_features.adx_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(name) => bug!("unknown target feature gate {}", name), |
| None => true, |
| }; |
| if !allowed && id.is_local() { |
| 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: DefId, 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 whitelist them anyway and trust that |
| // the user knows what s/he's 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, |
| _ => { |
| let span = tcx.hir().span_if_local(def_id); |
| if let Some(span) = span { |
| tcx.sess.span_fatal(span, "invalid linkage specified") |
| } else { |
| tcx.sess.fatal(&format!("invalid linkage specified: {}", name)) |
| } |
| } |
| } |
| } |
| |
| fn codegen_fn_attrs(tcx: TyCtxt<'_>, id: DefId) -> CodegenFnAttrs { |
| let attrs = tcx.get_attrs(id); |
| |
| let mut codegen_fn_attrs = CodegenFnAttrs::new(); |
| if should_inherit_track_caller(tcx, id) { |
| codegen_fn_attrs.flags |= CodegenFnAttrFlags::TRACK_CALLER; |
| } |
| |
| let whitelist = tcx.target_features_whitelist(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.check_name(sym::cold) { |
| codegen_fn_attrs.flags |= CodegenFnAttrFlags::COLD; |
| } else if attr.check_name(sym::rustc_allocator) { |
| codegen_fn_attrs.flags |= CodegenFnAttrFlags::ALLOCATOR; |
| } else if attr.check_name(sym::unwind) { |
| codegen_fn_attrs.flags |= CodegenFnAttrFlags::UNWIND; |
| } else if attr.check_name(sym::ffi_returns_twice) { |
| if tcx.is_foreign_item(id) { |
| 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.check_name(sym::rustc_allocator_nounwind) { |
| codegen_fn_attrs.flags |= CodegenFnAttrFlags::RUSTC_ALLOCATOR_NOUNWIND; |
| } else if attr.check_name(sym::naked) { |
| codegen_fn_attrs.flags |= CodegenFnAttrFlags::NAKED; |
| } else if attr.check_name(sym::no_mangle) { |
| codegen_fn_attrs.flags |= CodegenFnAttrFlags::NO_MANGLE; |
| } else if attr.check_name(sym::rustc_std_internal_symbol) { |
| codegen_fn_attrs.flags |= CodegenFnAttrFlags::RUSTC_STD_INTERNAL_SYMBOL; |
| } else if attr.check_name(sym::used) { |
| codegen_fn_attrs.flags |= CodegenFnAttrFlags::USED; |
| } else if attr.check_name(sym::thread_local) { |
| codegen_fn_attrs.flags |= CodegenFnAttrFlags::THREAD_LOCAL; |
| } else if attr.check_name(sym::track_caller) { |
| if tcx.is_closure(id) || tcx.fn_sig(id).abi() != abi::Abi::Rust { |
| struct_span_err!(tcx.sess, attr.span, E0737, "`#[track_caller]` requires Rust ABI") |
| .emit(); |
| } |
| codegen_fn_attrs.flags |= CodegenFnAttrFlags::TRACK_CALLER; |
| } else if attr.check_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.check_name(sym::target_feature) { |
| if tcx.is_closure(id) || tcx.fn_sig(id).unsafety() == Unsafety::Normal { |
| let msg = "`#[target_feature(..)]` can only be applied to `unsafe` functions"; |
| tcx.sess |
| .struct_span_err(attr.span, msg) |
| .span_label(attr.span, "can only be applied to `unsafe` functions") |
| .span_label(tcx.def_span(id), "not an `unsafe` function") |
| .emit(); |
| } |
| from_target_feature(tcx, id, attr, &whitelist, &mut codegen_fn_attrs.target_features); |
| } else if attr.check_name(sym::linkage) { |
| if let Some(val) = attr.value_str() { |
| codegen_fn_attrs.linkage = Some(linkage_by_name(tcx, id, &val.as_str())); |
| } |
| } else if attr.check_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.check_name(sym::link_name) { |
| codegen_fn_attrs.link_name = attr.value_str(); |
| } else if attr.check_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.check_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.check_name(sym::address) { |
| codegen_fn_attrs.flags |= CodegenFnAttrFlags::NO_SANITIZE_ADDRESS; |
| } else if item.check_name(sym::memory) { |
| codegen_fn_attrs.flags |= CodegenFnAttrFlags::NO_SANITIZE_MEMORY; |
| } else if item.check_name(sym::thread) { |
| codegen_fn_attrs.flags |= CodegenFnAttrFlags::NO_SANITIZE_THREAD; |
| } else { |
| tcx.sess |
| .struct_span_err(item.span(), "invalid argument for `no_sanitize`") |
| .note("expected one of: `address`, `memory` or `thread`") |
| .emit(); |
| } |
| } |
| } |
| } |
| } |
| |
| codegen_fn_attrs.inline = attrs.iter().fold(InlineAttr::None, |ia, attr| { |
| if !attr.has_name(sym::inline) { |
| return ia; |
| } |
| match attr.meta().map(|i| i.kind) { |
| Some(MetaItemKind::Word) => { |
| mark_used(attr); |
| InlineAttr::Hint |
| } |
| Some(MetaItemKind::List(ref items)) => { |
| mark_used(attr); |
| 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" |
| ) |
| .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().map(|i| i.kind) { |
| Some(MetaItemKind::Word) => { |
| err(attr.span, "expected one argument"); |
| ia |
| } |
| Some(MetaItemKind::List(ref items)) => { |
| mark_used(attr); |
| 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, |
| } |
| }); |
| |
| // 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.flags.intersects(CodegenFnAttrFlags::NO_SANITIZE_ANY) { |
| 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().as_local_hir_id(id).unwrap(); |
| 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(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; |
| } |
| |
| codegen_fn_attrs |
| } |
| |
| /// 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) { |
| if let ty::AssocItemContainer::ImplContainer(impl_def_id) = impl_item.container { |
| if let Some(trait_def_id) = tcx.trait_id_of_impl(impl_def_id) { |
| if let Some(trait_item) = tcx |
| .associated_items(trait_def_id) |
| .filter_by_name_unhygienic(impl_item.ident.name) |
| .find(move |trait_item| { |
| trait_item.kind == ty::AssocKind::Method |
| && tcx.hygienic_eq(impl_item.ident, trait_item.ident, trait_def_id) |
| }) |
| { |
| return tcx |
| .codegen_fn_attrs(trait_item.def_id) |
| .flags |
| .intersects(CodegenFnAttrFlags::TRACK_CALLER); |
| } |
| } |
| } |
| } |
| |
| false |
| } |
| |
| fn check_link_ordinal(tcx: TyCtxt<'_>, attr: &ast::Attribute) -> Option<usize> { |
| use rustc_ast::ast::{Lit, LitIntType, LitKind}; |
| 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(), |
| _ => None, |
| }; |
| if let Some(Lit { kind: LitKind::Int(ordinal, LitIntType::Unsuffixed), .. }) = sole_meta_list { |
| if *ordinal <= std::usize::MAX as u128 { |
| Some(*ordinal as usize) |
| } 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 `std::usize::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); |
| } |
| } |