2911 lines
111 KiB
Rust
2911 lines
111 KiB
Rust
//! "Collection" is the process of determining the type and other external
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//! details of each item in Rust. Collection is specifically concerned
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//! with *inter-procedural* things -- for example, for a function
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//! definition, collection will figure out the type and signature of the
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//! function, but it will not visit the *body* of the function in any way,
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//! nor examine type annotations on local variables (that's the job of
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//! type *checking*).
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//!
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//! Collecting is ultimately defined by a bundle of queries that
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//! inquire after various facts about the items in the crate (e.g.,
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//! `type_of`, `generics_of`, `predicates_of`, etc). See the `provide` function
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//! for the full set.
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//!
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//! At present, however, we do run collection across all items in the
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//! crate as a kind of pass. This should eventually be factored away.
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use crate::astconv::{AstConv, Bounds, SizedByDefault};
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use crate::check::intrinsic::intrinsic_operation_unsafety;
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use crate::constrained_generic_params as cgp;
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use crate::lint;
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use crate::middle::resolve_lifetime as rl;
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use crate::middle::weak_lang_items;
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use errors::{struct_span_err, Applicability, StashKey};
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use rustc::hir::intravisit::{self, NestedVisitorMap, Visitor};
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use rustc::middle::codegen_fn_attrs::{CodegenFnAttrFlags, CodegenFnAttrs};
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use rustc::mir::mono::Linkage;
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use rustc::traits;
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use rustc::ty::query::Providers;
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use rustc::ty::subst::GenericArgKind;
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use rustc::ty::subst::{InternalSubsts, Subst};
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use rustc::ty::util::Discr;
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use rustc::ty::util::IntTypeExt;
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use rustc::ty::{self, AdtKind, Const, DefIdTree, ToPolyTraitRef, Ty, TyCtxt};
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use rustc::ty::{ReprOptions, ToPredicate};
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use rustc::util::captures::Captures;
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use rustc_data_structures::fx::FxHashMap;
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use rustc_hir as hir;
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use rustc_hir::def::{CtorKind, DefKind, Res};
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use rustc_hir::def_id::{DefId, LOCAL_CRATE};
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use rustc_hir::{GenericParamKind, Node, Unsafety};
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use rustc_span::symbol::{kw, sym, Symbol};
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use rustc_span::{Span, DUMMY_SP};
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use rustc_target::spec::abi;
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use syntax::ast;
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use syntax::ast::{Ident, MetaItemKind};
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use syntax::attr::{list_contains_name, mark_used, InlineAttr, OptimizeAttr};
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use syntax::feature_gate;
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use rustc_error_codes::*;
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struct OnlySelfBounds(bool);
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///////////////////////////////////////////////////////////////////////////
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// Main entry point
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fn collect_mod_item_types(tcx: TyCtxt<'_>, module_def_id: DefId) {
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tcx.hir().visit_item_likes_in_module(
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module_def_id,
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&mut CollectItemTypesVisitor { tcx }.as_deep_visitor(),
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);
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}
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pub fn provide(providers: &mut Providers<'_>) {
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*providers = Providers {
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type_of,
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generics_of,
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predicates_of,
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predicates_defined_on,
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explicit_predicates_of,
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super_predicates_of,
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type_param_predicates,
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trait_def,
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adt_def,
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fn_sig,
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impl_trait_ref,
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impl_polarity,
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is_foreign_item,
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static_mutability,
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codegen_fn_attrs,
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collect_mod_item_types,
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..*providers
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};
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}
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///////////////////////////////////////////////////////////////////////////
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/// Context specific to some particular item. This is what implements
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/// `AstConv`. It has information about the predicates that are defined
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/// on the trait. Unfortunately, this predicate information is
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/// available in various different forms at various points in the
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/// process. So we can't just store a pointer to e.g., the AST or the
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/// parsed ty form, we have to be more flexible. To this end, the
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/// `ItemCtxt` is parameterized by a `DefId` that it uses to satisfy
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/// `get_type_parameter_bounds` requests, drawing the information from
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/// the AST (`hir::Generics`), recursively.
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pub struct ItemCtxt<'tcx> {
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tcx: TyCtxt<'tcx>,
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item_def_id: DefId,
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}
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///////////////////////////////////////////////////////////////////////////
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#[derive(Default)]
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crate struct PlaceholderHirTyCollector(crate Vec<Span>);
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impl<'v> Visitor<'v> for PlaceholderHirTyCollector {
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fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'v> {
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NestedVisitorMap::None
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}
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fn visit_ty(&mut self, t: &'v hir::Ty<'v>) {
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if let hir::TyKind::Infer = t.kind {
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self.0.push(t.span);
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}
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intravisit::walk_ty(self, t)
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}
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}
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struct CollectItemTypesVisitor<'tcx> {
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tcx: TyCtxt<'tcx>,
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}
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/// If there are any placeholder types (`_`), emit an error explaining that this is not allowed
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/// and suggest adding type parameters in the appropriate place, taking into consideration any and
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/// all already existing generic type parameters to avoid suggesting a name that is already in use.
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crate fn placeholder_type_error(
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tcx: TyCtxt<'tcx>,
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ident_span: Span,
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generics: &[hir::GenericParam<'_>],
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placeholder_types: Vec<Span>,
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suggest: bool,
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) {
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if placeholder_types.is_empty() {
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return;
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}
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// This is the whitelist of possible parameter names that we might suggest.
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let possible_names = ["T", "K", "L", "A", "B", "C"];
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let used_names = generics
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.iter()
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.filter_map(|p| match p.name {
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hir::ParamName::Plain(ident) => Some(ident.name),
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_ => None,
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})
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.collect::<Vec<_>>();
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let type_name = possible_names
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.iter()
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.find(|n| !used_names.contains(&Symbol::intern(n)))
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.unwrap_or(&"ParamName");
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let mut sugg: Vec<_> =
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placeholder_types.iter().map(|sp| (*sp, type_name.to_string())).collect();
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if generics.is_empty() {
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sugg.push((ident_span.shrink_to_hi(), format!("<{}>", type_name)));
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} else {
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sugg.push((
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generics.iter().last().unwrap().span.shrink_to_hi(),
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format!(", {}", type_name),
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));
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}
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let mut err = bad_placeholder_type(tcx, placeholder_types);
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if suggest {
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err.multipart_suggestion(
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"use type parameters instead",
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sugg,
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Applicability::HasPlaceholders,
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);
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}
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err.emit();
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}
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fn reject_placeholder_type_signatures_in_item(tcx: TyCtxt<'tcx>, item: &'tcx hir::Item<'tcx>) {
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let (generics, suggest) = match &item.kind {
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hir::ItemKind::Union(_, generics)
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| hir::ItemKind::Enum(_, generics)
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| hir::ItemKind::Struct(_, generics) => (&generics.params[..], true),
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hir::ItemKind::TyAlias(_, generics) => (&generics.params[..], false),
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// `static`, `fn` and `const` are handled elsewhere to suggest appropriate type.
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_ => return,
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};
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let mut visitor = PlaceholderHirTyCollector::default();
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visitor.visit_item(item);
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placeholder_type_error(tcx, item.ident.span, generics, visitor.0, suggest);
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}
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impl Visitor<'tcx> for CollectItemTypesVisitor<'tcx> {
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fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
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NestedVisitorMap::OnlyBodies(&self.tcx.hir())
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}
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fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
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convert_item(self.tcx, item.hir_id);
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reject_placeholder_type_signatures_in_item(self.tcx, item);
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intravisit::walk_item(self, item);
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}
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fn visit_generics(&mut self, generics: &'tcx hir::Generics<'tcx>) {
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for param in generics.params {
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match param.kind {
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hir::GenericParamKind::Lifetime { .. } => {}
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hir::GenericParamKind::Type { default: Some(_), .. } => {
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let def_id = self.tcx.hir().local_def_id(param.hir_id);
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self.tcx.type_of(def_id);
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}
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hir::GenericParamKind::Type { .. } => {}
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hir::GenericParamKind::Const { .. } => {
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let def_id = self.tcx.hir().local_def_id(param.hir_id);
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self.tcx.type_of(def_id);
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}
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}
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}
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intravisit::walk_generics(self, generics);
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}
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fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) {
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if let hir::ExprKind::Closure(..) = expr.kind {
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let def_id = self.tcx.hir().local_def_id(expr.hir_id);
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self.tcx.generics_of(def_id);
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self.tcx.type_of(def_id);
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}
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intravisit::walk_expr(self, expr);
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}
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fn visit_trait_item(&mut self, trait_item: &'tcx hir::TraitItem<'tcx>) {
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convert_trait_item(self.tcx, trait_item.hir_id);
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intravisit::walk_trait_item(self, trait_item);
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}
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fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem<'tcx>) {
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convert_impl_item(self.tcx, impl_item.hir_id);
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intravisit::walk_impl_item(self, impl_item);
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}
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}
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///////////////////////////////////////////////////////////////////////////
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// Utility types and common code for the above passes.
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fn bad_placeholder_type(
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tcx: TyCtxt<'tcx>,
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mut spans: Vec<Span>,
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) -> errors::DiagnosticBuilder<'tcx> {
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spans.sort();
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let mut err = struct_span_err!(
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tcx.sess,
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spans.clone(),
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E0121,
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"the type placeholder `_` is not allowed within types on item signatures",
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);
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for span in spans {
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err.span_label(span, "not allowed in type signatures");
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}
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err
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}
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impl ItemCtxt<'tcx> {
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pub fn new(tcx: TyCtxt<'tcx>, item_def_id: DefId) -> ItemCtxt<'tcx> {
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ItemCtxt { tcx, item_def_id }
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}
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pub fn to_ty(&self, ast_ty: &'tcx hir::Ty<'tcx>) -> Ty<'tcx> {
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AstConv::ast_ty_to_ty(self, ast_ty)
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}
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}
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impl AstConv<'tcx> for ItemCtxt<'tcx> {
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fn tcx(&self) -> TyCtxt<'tcx> {
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self.tcx
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}
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fn item_def_id(&self) -> Option<DefId> {
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Some(self.item_def_id)
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}
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fn get_type_parameter_bounds(&self, span: Span, def_id: DefId) -> ty::GenericPredicates<'tcx> {
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self.tcx.at(span).type_param_predicates((self.item_def_id, def_id))
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}
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fn re_infer(&self, _: Option<&ty::GenericParamDef>, _: Span) -> Option<ty::Region<'tcx>> {
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None
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}
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fn allow_ty_infer(&self) -> bool {
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false
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}
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fn ty_infer(&self, _: Option<&ty::GenericParamDef>, span: Span) -> Ty<'tcx> {
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self.tcx().sess.delay_span_bug(span, "bad placeholder type");
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self.tcx().types.err
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}
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fn ct_infer(
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&self,
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_: Ty<'tcx>,
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_: Option<&ty::GenericParamDef>,
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span: Span,
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) -> &'tcx Const<'tcx> {
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bad_placeholder_type(self.tcx(), vec![span]).emit();
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self.tcx().consts.err
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}
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fn projected_ty_from_poly_trait_ref(
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&self,
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span: Span,
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item_def_id: DefId,
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item_segment: &hir::PathSegment<'_>,
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poly_trait_ref: ty::PolyTraitRef<'tcx>,
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) -> Ty<'tcx> {
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if let Some(trait_ref) = poly_trait_ref.no_bound_vars() {
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let item_substs = <dyn AstConv<'tcx>>::create_substs_for_associated_item(
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self,
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self.tcx,
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span,
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item_def_id,
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item_segment,
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trait_ref.substs,
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);
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self.tcx().mk_projection(item_def_id, item_substs)
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} else {
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// There are no late-bound regions; we can just ignore the binder.
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struct_span_err!(
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self.tcx().sess,
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span,
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E0212,
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"cannot extract an associated type from a higher-ranked trait bound \
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in this context"
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)
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.emit();
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self.tcx().types.err
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}
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}
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fn normalize_ty(&self, _span: Span, ty: Ty<'tcx>) -> Ty<'tcx> {
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// Types in item signatures are not normalized to avoid undue dependencies.
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ty
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}
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fn set_tainted_by_errors(&self) {
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// There's no obvious place to track this, so just let it go.
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}
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fn record_ty(&self, _hir_id: hir::HirId, _ty: Ty<'tcx>, _span: Span) {
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// There's no place to record types from signatures?
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}
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}
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/// Returns the predicates defined on `item_def_id` of the form
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/// `X: Foo` where `X` is the type parameter `def_id`.
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fn type_param_predicates(
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tcx: TyCtxt<'_>,
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(item_def_id, def_id): (DefId, DefId),
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) -> ty::GenericPredicates<'_> {
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use rustc_hir::*;
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// In the AST, bounds can derive from two places. Either
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// written inline like `<T: Foo>` or in a where-clause like
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// `where T: Foo`.
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let param_id = tcx.hir().as_local_hir_id(def_id).unwrap();
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let param_owner = tcx.hir().ty_param_owner(param_id);
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let param_owner_def_id = tcx.hir().local_def_id(param_owner);
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let generics = tcx.generics_of(param_owner_def_id);
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let index = generics.param_def_id_to_index[&def_id];
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let ty = tcx.mk_ty_param(index, tcx.hir().ty_param_name(param_id));
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// Don't look for bounds where the type parameter isn't in scope.
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let parent =
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if item_def_id == param_owner_def_id { None } else { tcx.generics_of(item_def_id).parent };
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let mut result = parent
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.map(|parent| {
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let icx = ItemCtxt::new(tcx, parent);
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icx.get_type_parameter_bounds(DUMMY_SP, def_id)
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})
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.unwrap_or_default();
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let mut extend = None;
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|
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let item_hir_id = tcx.hir().as_local_hir_id(item_def_id).unwrap();
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let ast_generics = match tcx.hir().get(item_hir_id) {
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Node::TraitItem(item) => &item.generics,
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|
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|
Node::ImplItem(item) => &item.generics,
|
|
|
|
Node::Item(item) => {
|
|
match item.kind {
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|
ItemKind::Fn(.., ref generics, _)
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|
| ItemKind::Impl(_, _, _, ref generics, ..)
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|
| ItemKind::TyAlias(_, ref generics)
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|
| ItemKind::OpaqueTy(OpaqueTy { ref generics, impl_trait_fn: None, .. })
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|
| ItemKind::Enum(_, ref generics)
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|
| ItemKind::Struct(_, ref generics)
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|
| ItemKind::Union(_, ref generics) => generics,
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|
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);
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|
extend = Some((identity_trait_ref.to_predicate(), item.span));
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|
}
|
|
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(
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|
icx.type_parameter_bounds_in_generics(ast_generics, param_id, ty, OnlySelfBounds(true))
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|
.into_iter()
|
|
.filter(|(predicate, _)| match predicate {
|
|
ty::Predicate::Trait(ref data) => data.skip_binder().self_ty().is_param(index),
|
|
_ => false,
|
|
}),
|
|
);
|
|
result.predicates =
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|
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 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));
|
|
|
|
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));
|
|
|
|
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::Const(..)
|
|
| hir::TraitItemKind::Type(_, Some(_))
|
|
| hir::TraitItemKind::Method(..) => {
|
|
tcx.type_of(def_id);
|
|
if let hir::TraitItemKind::Method(..) = trait_item.kind {
|
|
tcx.fn_sig(def_id);
|
|
}
|
|
}
|
|
|
|
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);
|
|
if let hir::ImplItemKind::Method(..) = tcx.hir().expect_impl_item(impl_item_id).kind {
|
|
tcx.fn_sig(def_id);
|
|
}
|
|
}
|
|
|
|
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.modern()).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.modern(), 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 def_path_hash = tcx.def_path_hash(def_id);
|
|
let def = ty::TraitDef::new(def_id, unsafety, paren_sugar, is_auto, is_marker, 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> {
|
|
fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
|
|
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::Method(ref sig, _) => {
|
|
has_late_bound_regions(tcx, &item.generics, &sig.decl)
|
|
}
|
|
_ => None,
|
|
},
|
|
Node::ImplItem(item) => match item.kind {
|
|
hir::ImplItemKind::Method(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,
|
|
_ => 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 parameters.
|
|
let type_start = own_start - has_self as u32 + params.len() as u32;
|
|
let mut i = 0;
|
|
params.extend(ast_generics.params.iter().filter_map(|param| {
|
|
let kind = match param.kind {
|
|
GenericParamKind::Type { ref default, synthetic, .. } => {
|
|
if !allow_defaults && default.is_some() {
|
|
if !tcx.features().default_type_parameter_fallback {
|
|
tcx.lint_hir(
|
|
lint::builtin::INVALID_TYPE_PARAM_DEFAULT,
|
|
param.hir_id,
|
|
param.span,
|
|
&format!(
|
|
"defaults for type parameters are only allowed in \
|
|
`struct`, `enum`, `type`, or `trait` definitions."
|
|
),
|
|
);
|
|
}
|
|
}
|
|
|
|
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,
|
|
}
|
|
}
|
|
GenericParamKind::Const { .. } => ty::GenericParamDefKind::Const,
|
|
_ => return None,
|
|
};
|
|
|
|
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)
|
|
}));
|
|
|
|
// 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() {
|
|
&["<yield_ty>", "<return_ty>", "<witness>"][..]
|
|
} else {
|
|
&["<closure_kind>", "<closure_signature>"][..]
|
|
};
|
|
|
|
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,
|
|
},
|
|
}));
|
|
|
|
if let Some(upvars) = tcx.upvars(def_id) {
|
|
params.extend(upvars.iter().zip((dummy_args.len() as u32)..).map(|(_, i)| {
|
|
ty::GenericParamDef {
|
|
index: type_start + i,
|
|
name: Symbol::intern("<upvar>"),
|
|
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 report_assoc_ty_on_inherent_impl(tcx: TyCtxt<'_>, span: Span) {
|
|
struct_span_err!(
|
|
tcx.sess,
|
|
span,
|
|
E0202,
|
|
"associated types are not yet supported in inherent impls (see #8995)"
|
|
)
|
|
.emit();
|
|
}
|
|
|
|
fn infer_placeholder_type(
|
|
tcx: TyCtxt<'_>,
|
|
def_id: DefId,
|
|
body_id: hir::BodyId,
|
|
span: Span,
|
|
item_ident: Ident,
|
|
) -> Ty<'_> {
|
|
let ty = tcx.diagnostic_only_typeck_tables_of(def_id).node_type(body_id.hir_id);
|
|
|
|
// If this came from a free `const` or `static mut?` item,
|
|
// then the user may have written e.g. `const A = 42;`.
|
|
// In this case, the parser has stashed a diagnostic for
|
|
// us to improve in typeck so we do that now.
|
|
match tcx.sess.diagnostic().steal_diagnostic(span, StashKey::ItemNoType) {
|
|
Some(mut err) => {
|
|
// The parser provided a sub-optimal `HasPlaceholders` suggestion for the type.
|
|
// We are typeck and have the real type, so remove that and suggest the actual type.
|
|
err.suggestions.clear();
|
|
err.span_suggestion(
|
|
span,
|
|
"provide a type for the item",
|
|
format!("{}: {}", item_ident, ty),
|
|
Applicability::MachineApplicable,
|
|
)
|
|
.emit();
|
|
}
|
|
None => {
|
|
let mut diag = bad_placeholder_type(tcx, vec![span]);
|
|
if ty != tcx.types.err {
|
|
diag.span_suggestion(
|
|
span,
|
|
"replace `_` with the correct type",
|
|
ty.to_string(),
|
|
Applicability::MaybeIncorrect,
|
|
);
|
|
}
|
|
diag.emit();
|
|
}
|
|
}
|
|
|
|
ty
|
|
}
|
|
|
|
fn type_of(tcx: TyCtxt<'_>, def_id: DefId) -> Ty<'_> {
|
|
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) {
|
|
Node::TraitItem(item) => match item.kind {
|
|
TraitItemKind::Method(..) => {
|
|
let substs = InternalSubsts::identity_for_item(tcx, def_id);
|
|
tcx.mk_fn_def(def_id, substs)
|
|
}
|
|
TraitItemKind::Const(ref ty, body_id) => body_id
|
|
.and_then(|body_id| {
|
|
if is_suggestable_infer_ty(ty) {
|
|
Some(infer_placeholder_type(tcx, def_id, body_id, ty.span, item.ident))
|
|
} else {
|
|
None
|
|
}
|
|
})
|
|
.unwrap_or_else(|| icx.to_ty(ty)),
|
|
TraitItemKind::Type(_, Some(ref ty)) => icx.to_ty(ty),
|
|
TraitItemKind::Type(_, None) => {
|
|
span_bug!(item.span, "associated type missing default");
|
|
}
|
|
},
|
|
|
|
Node::ImplItem(item) => match item.kind {
|
|
ImplItemKind::Method(..) => {
|
|
let substs = InternalSubsts::identity_for_item(tcx, def_id);
|
|
tcx.mk_fn_def(def_id, substs)
|
|
}
|
|
ImplItemKind::Const(ref ty, body_id) => {
|
|
if is_suggestable_infer_ty(ty) {
|
|
infer_placeholder_type(tcx, def_id, body_id, ty.span, item.ident)
|
|
} else {
|
|
icx.to_ty(ty)
|
|
}
|
|
}
|
|
ImplItemKind::OpaqueTy(_) => {
|
|
if tcx.impl_trait_ref(tcx.hir().get_parent_did(hir_id)).is_none() {
|
|
report_assoc_ty_on_inherent_impl(tcx, item.span);
|
|
}
|
|
|
|
find_opaque_ty_constraints(tcx, def_id)
|
|
}
|
|
ImplItemKind::TyAlias(ref ty) => {
|
|
if tcx.impl_trait_ref(tcx.hir().get_parent_did(hir_id)).is_none() {
|
|
report_assoc_ty_on_inherent_impl(tcx, item.span);
|
|
}
|
|
|
|
icx.to_ty(ty)
|
|
}
|
|
},
|
|
|
|
Node::Item(item) => {
|
|
match item.kind {
|
|
ItemKind::Static(ref ty, .., body_id) | ItemKind::Const(ref ty, body_id) => {
|
|
if is_suggestable_infer_ty(ty) {
|
|
infer_placeholder_type(tcx, def_id, body_id, ty.span, item.ident)
|
|
} else {
|
|
icx.to_ty(ty)
|
|
}
|
|
}
|
|
ItemKind::TyAlias(ref ty, _) | ItemKind::Impl(.., ref ty, _) => icx.to_ty(ty),
|
|
ItemKind::Fn(..) => {
|
|
let substs = InternalSubsts::identity_for_item(tcx, def_id);
|
|
tcx.mk_fn_def(def_id, substs)
|
|
}
|
|
ItemKind::Enum(..) | ItemKind::Struct(..) | ItemKind::Union(..) => {
|
|
let def = tcx.adt_def(def_id);
|
|
let substs = InternalSubsts::identity_for_item(tcx, def_id);
|
|
tcx.mk_adt(def, substs)
|
|
}
|
|
ItemKind::OpaqueTy(hir::OpaqueTy { impl_trait_fn: None, .. }) => {
|
|
find_opaque_ty_constraints(tcx, def_id)
|
|
}
|
|
// Opaque types desugared from `impl Trait`.
|
|
ItemKind::OpaqueTy(hir::OpaqueTy { impl_trait_fn: Some(owner), .. }) => {
|
|
tcx.typeck_tables_of(owner)
|
|
.concrete_opaque_types
|
|
.get(&def_id)
|
|
.map(|opaque| opaque.concrete_type)
|
|
.unwrap_or_else(|| {
|
|
// This can occur if some error in the
|
|
// owner fn prevented us from populating
|
|
// the `concrete_opaque_types` table.
|
|
tcx.sess.delay_span_bug(
|
|
DUMMY_SP,
|
|
&format!(
|
|
"owner {:?} has no opaque type for {:?} in its tables",
|
|
owner, def_id,
|
|
),
|
|
);
|
|
tcx.types.err
|
|
})
|
|
}
|
|
ItemKind::Trait(..)
|
|
| ItemKind::TraitAlias(..)
|
|
| ItemKind::Mod(..)
|
|
| ItemKind::ForeignMod(..)
|
|
| ItemKind::GlobalAsm(..)
|
|
| ItemKind::ExternCrate(..)
|
|
| ItemKind::Use(..) => {
|
|
span_bug!(
|
|
item.span,
|
|
"compute_type_of_item: unexpected item type: {:?}",
|
|
item.kind
|
|
);
|
|
}
|
|
}
|
|
}
|
|
|
|
Node::ForeignItem(foreign_item) => match foreign_item.kind {
|
|
ForeignItemKind::Fn(..) => {
|
|
let substs = InternalSubsts::identity_for_item(tcx, def_id);
|
|
tcx.mk_fn_def(def_id, substs)
|
|
}
|
|
ForeignItemKind::Static(ref t, _) => icx.to_ty(t),
|
|
ForeignItemKind::Type => tcx.mk_foreign(def_id),
|
|
},
|
|
|
|
Node::Ctor(&ref def) | Node::Variant(hir::Variant { data: ref def, .. }) => match *def {
|
|
VariantData::Unit(..) | VariantData::Struct(..) => {
|
|
tcx.type_of(tcx.hir().get_parent_did(hir_id))
|
|
}
|
|
VariantData::Tuple(..) => {
|
|
let substs = InternalSubsts::identity_for_item(tcx, def_id);
|
|
tcx.mk_fn_def(def_id, substs)
|
|
}
|
|
},
|
|
|
|
Node::Field(field) => icx.to_ty(&field.ty),
|
|
|
|
Node::Expr(&hir::Expr { kind: hir::ExprKind::Closure(.., gen), .. }) => {
|
|
if gen.is_some() {
|
|
return tcx.typeck_tables_of(def_id).node_type(hir_id);
|
|
}
|
|
|
|
let substs = InternalSubsts::identity_for_item(tcx, def_id);
|
|
tcx.mk_closure(def_id, substs)
|
|
}
|
|
|
|
Node::AnonConst(_) => {
|
|
let parent_node = tcx.hir().get(tcx.hir().get_parent_node(hir_id));
|
|
match parent_node {
|
|
Node::Ty(&hir::Ty { kind: hir::TyKind::Array(_, ref constant), .. })
|
|
| Node::Ty(&hir::Ty { kind: hir::TyKind::Typeof(ref constant), .. })
|
|
| Node::Expr(&hir::Expr { kind: ExprKind::Repeat(_, ref constant), .. })
|
|
if constant.hir_id == hir_id =>
|
|
{
|
|
tcx.types.usize
|
|
}
|
|
|
|
Node::Variant(Variant { disr_expr: Some(ref e), .. }) if e.hir_id == hir_id => {
|
|
tcx.adt_def(tcx.hir().get_parent_did(hir_id)).repr.discr_type().to_ty(tcx)
|
|
}
|
|
|
|
Node::Ty(&hir::Ty { kind: hir::TyKind::Path(_), .. })
|
|
| Node::Expr(&hir::Expr { kind: ExprKind::Struct(..), .. })
|
|
| Node::Expr(&hir::Expr { kind: ExprKind::Path(_), .. })
|
|
| Node::TraitRef(..) => {
|
|
let path = match parent_node {
|
|
Node::Ty(&hir::Ty {
|
|
kind: hir::TyKind::Path(QPath::Resolved(_, ref path)),
|
|
..
|
|
})
|
|
| Node::Expr(&hir::Expr {
|
|
kind: ExprKind::Path(QPath::Resolved(_, ref path)),
|
|
..
|
|
}) => Some(&**path),
|
|
Node::Expr(&hir::Expr { kind: ExprKind::Struct(ref path, ..), .. }) => {
|
|
if let QPath::Resolved(_, ref path) = **path {
|
|
Some(&**path)
|
|
} else {
|
|
None
|
|
}
|
|
}
|
|
Node::TraitRef(&hir::TraitRef { ref path, .. }) => Some(&**path),
|
|
_ => None,
|
|
};
|
|
|
|
if let Some(path) = path {
|
|
let arg_index = path
|
|
.segments
|
|
.iter()
|
|
.filter_map(|seg| seg.args.as_ref())
|
|
.map(|generic_args| generic_args.args.as_ref())
|
|
.find_map(|args| {
|
|
args.iter()
|
|
.filter(|arg| arg.is_const())
|
|
.enumerate()
|
|
.filter(|(_, arg)| arg.id() == hir_id)
|
|
.map(|(index, _)| index)
|
|
.next()
|
|
})
|
|
.unwrap_or_else(|| {
|
|
bug!("no arg matching AnonConst in path");
|
|
});
|
|
|
|
// We've encountered an `AnonConst` in some path, so we need to
|
|
// figure out which generic parameter it corresponds to and return
|
|
// the relevant type.
|
|
let generics = match path.res {
|
|
Res::Def(DefKind::Ctor(..), def_id) => {
|
|
tcx.generics_of(tcx.parent(def_id).unwrap())
|
|
}
|
|
Res::Def(_, def_id) => tcx.generics_of(def_id),
|
|
Res::Err => return tcx.types.err,
|
|
res => {
|
|
tcx.sess.delay_span_bug(
|
|
DUMMY_SP,
|
|
&format!("unexpected const parent path def {:?}", res,),
|
|
);
|
|
return tcx.types.err;
|
|
}
|
|
};
|
|
|
|
generics
|
|
.params
|
|
.iter()
|
|
.filter(|param| {
|
|
if let ty::GenericParamDefKind::Const = param.kind {
|
|
true
|
|
} else {
|
|
false
|
|
}
|
|
})
|
|
.nth(arg_index)
|
|
.map(|param| tcx.type_of(param.def_id))
|
|
// This is no generic parameter associated with the arg. This is
|
|
// probably from an extra arg where one is not needed.
|
|
.unwrap_or(tcx.types.err)
|
|
} else {
|
|
tcx.sess.delay_span_bug(
|
|
DUMMY_SP,
|
|
&format!("unexpected const parent path {:?}", parent_node,),
|
|
);
|
|
return tcx.types.err;
|
|
}
|
|
}
|
|
|
|
x => {
|
|
tcx.sess.delay_span_bug(
|
|
DUMMY_SP,
|
|
&format!("unexpected const parent in type_of_def_id(): {:?}", x),
|
|
);
|
|
tcx.types.err
|
|
}
|
|
}
|
|
}
|
|
|
|
Node::GenericParam(param) => match ¶m.kind {
|
|
hir::GenericParamKind::Type { default: Some(ref ty), .. } => icx.to_ty(ty),
|
|
hir::GenericParamKind::Const { ty: ref hir_ty, .. } => {
|
|
let ty = icx.to_ty(hir_ty);
|
|
if !tcx.features().const_compare_raw_pointers {
|
|
let err = match ty.peel_refs().kind {
|
|
ty::FnPtr(_) => Some("function pointers"),
|
|
ty::RawPtr(_) => Some("raw pointers"),
|
|
_ => None,
|
|
};
|
|
if let Some(unsupported_type) = err {
|
|
feature_gate::feature_err(
|
|
&tcx.sess.parse_sess,
|
|
sym::const_compare_raw_pointers,
|
|
hir_ty.span,
|
|
&format!(
|
|
"using {} as const generic parameters is unstable",
|
|
unsupported_type
|
|
),
|
|
)
|
|
.emit();
|
|
};
|
|
}
|
|
if traits::search_for_structural_match_violation(param.hir_id, param.span, tcx, ty)
|
|
.is_some()
|
|
{
|
|
struct_span_err!(
|
|
tcx.sess,
|
|
hir_ty.span,
|
|
E0741,
|
|
"the types of const generic parameters must derive `PartialEq` and `Eq`",
|
|
)
|
|
.span_label(
|
|
hir_ty.span,
|
|
format!("`{}` doesn't derive both `PartialEq` and `Eq`", ty),
|
|
)
|
|
.emit();
|
|
}
|
|
ty
|
|
}
|
|
x => bug!("unexpected non-type Node::GenericParam: {:?}", x),
|
|
},
|
|
|
|
x => {
|
|
bug!("unexpected sort of node in type_of_def_id(): {:?}", x);
|
|
}
|
|
}
|
|
}
|
|
|
|
fn find_opaque_ty_constraints(tcx: TyCtxt<'_>, def_id: DefId) -> Ty<'_> {
|
|
use rustc_hir::{ImplItem, Item, TraitItem};
|
|
|
|
debug!("find_opaque_ty_constraints({:?})", def_id);
|
|
|
|
struct ConstraintLocator<'tcx> {
|
|
tcx: TyCtxt<'tcx>,
|
|
def_id: DefId,
|
|
// (first found type span, actual type, mapping from the opaque type's generic
|
|
// parameters to the concrete type's generic parameters)
|
|
//
|
|
// The mapping is an index for each use site of a generic parameter in the concrete type
|
|
//
|
|
// The indices index into the generic parameters on the opaque type.
|
|
found: Option<(Span, Ty<'tcx>, Vec<usize>)>,
|
|
}
|
|
|
|
impl ConstraintLocator<'tcx> {
|
|
fn check(&mut self, def_id: DefId) {
|
|
// Don't try to check items that cannot possibly constrain the type.
|
|
if !self.tcx.has_typeck_tables(def_id) {
|
|
debug!(
|
|
"find_opaque_ty_constraints: no constraint for `{:?}` at `{:?}`: no tables",
|
|
self.def_id, def_id,
|
|
);
|
|
return;
|
|
}
|
|
let ty = self.tcx.typeck_tables_of(def_id).concrete_opaque_types.get(&self.def_id);
|
|
if let Some(ty::ResolvedOpaqueTy { concrete_type, substs }) = ty {
|
|
debug!(
|
|
"find_opaque_ty_constraints: found constraint for `{:?}` at `{:?}`: {:?}",
|
|
self.def_id, def_id, ty,
|
|
);
|
|
|
|
// FIXME(oli-obk): trace the actual span from inference to improve errors.
|
|
let span = self.tcx.def_span(def_id);
|
|
// used to quickly look up the position of a generic parameter
|
|
let mut index_map: FxHashMap<ty::ParamTy, usize> = FxHashMap::default();
|
|
// Skipping binder is ok, since we only use this to find generic parameters and
|
|
// their positions.
|
|
for (idx, subst) in substs.iter().enumerate() {
|
|
if let GenericArgKind::Type(ty) = subst.unpack() {
|
|
if let ty::Param(p) = ty.kind {
|
|
if index_map.insert(p, idx).is_some() {
|
|
// There was already an entry for `p`, meaning a generic parameter
|
|
// was used twice.
|
|
self.tcx.sess.span_err(
|
|
span,
|
|
&format!(
|
|
"defining opaque type use restricts opaque \
|
|
type by using the generic parameter `{}` twice",
|
|
p,
|
|
),
|
|
);
|
|
return;
|
|
}
|
|
} else {
|
|
self.tcx.sess.delay_span_bug(
|
|
span,
|
|
&format!(
|
|
"non-defining opaque ty use in defining scope: {:?}, {:?}",
|
|
concrete_type, substs,
|
|
),
|
|
);
|
|
}
|
|
}
|
|
}
|
|
// Compute the index within the opaque type for each generic parameter used in
|
|
// the concrete type.
|
|
let indices = concrete_type
|
|
.subst(self.tcx, substs)
|
|
.walk()
|
|
.filter_map(|t| match &t.kind {
|
|
ty::Param(p) => Some(*index_map.get(p).unwrap()),
|
|
_ => None,
|
|
})
|
|
.collect();
|
|
let is_param = |ty: Ty<'_>| match ty.kind {
|
|
ty::Param(_) => true,
|
|
_ => false,
|
|
};
|
|
let bad_substs: Vec<_> =
|
|
substs.types().enumerate().filter(|(_, ty)| !is_param(ty)).collect();
|
|
if !bad_substs.is_empty() {
|
|
let identity_substs = InternalSubsts::identity_for_item(self.tcx, self.def_id);
|
|
for (i, bad_subst) in bad_substs {
|
|
self.tcx.sess.span_err(
|
|
span,
|
|
&format!(
|
|
"defining opaque type use does not fully define opaque type: \
|
|
generic parameter `{}` is specified as concrete type `{}`",
|
|
identity_substs.type_at(i),
|
|
bad_subst
|
|
),
|
|
);
|
|
}
|
|
} else if let Some((prev_span, prev_ty, ref prev_indices)) = self.found {
|
|
let mut ty = concrete_type.walk().fuse();
|
|
let mut p_ty = prev_ty.walk().fuse();
|
|
let iter_eq = (&mut ty).zip(&mut p_ty).all(|(t, p)| match (&t.kind, &p.kind) {
|
|
// Type parameters are equal to any other type parameter for the purpose of
|
|
// concrete type equality, as it is possible to obtain the same type just
|
|
// by passing matching parameters to a function.
|
|
(ty::Param(_), ty::Param(_)) => true,
|
|
_ => t == p,
|
|
});
|
|
if !iter_eq || ty.next().is_some() || p_ty.next().is_some() {
|
|
debug!("find_opaque_ty_constraints: span={:?}", span);
|
|
// Found different concrete types for the opaque type.
|
|
let mut err = self.tcx.sess.struct_span_err(
|
|
span,
|
|
"concrete type differs from previous defining opaque type use",
|
|
);
|
|
err.span_label(
|
|
span,
|
|
format!("expected `{}`, got `{}`", prev_ty, concrete_type),
|
|
);
|
|
err.span_note(prev_span, "previous use here");
|
|
err.emit();
|
|
} else if indices != *prev_indices {
|
|
// Found "same" concrete types, but the generic parameter order differs.
|
|
let mut err = self.tcx.sess.struct_span_err(
|
|
span,
|
|
"concrete type's generic parameters differ from previous defining use",
|
|
);
|
|
use std::fmt::Write;
|
|
let mut s = String::new();
|
|
write!(s, "expected [").unwrap();
|
|
let list = |s: &mut String, indices: &Vec<usize>| {
|
|
let mut indices = indices.iter().cloned();
|
|
if let Some(first) = indices.next() {
|
|
write!(s, "`{}`", substs[first]).unwrap();
|
|
for i in indices {
|
|
write!(s, ", `{}`", substs[i]).unwrap();
|
|
}
|
|
}
|
|
};
|
|
list(&mut s, prev_indices);
|
|
write!(s, "], got [").unwrap();
|
|
list(&mut s, &indices);
|
|
write!(s, "]").unwrap();
|
|
err.span_label(span, s);
|
|
err.span_note(prev_span, "previous use here");
|
|
err.emit();
|
|
}
|
|
} else {
|
|
self.found = Some((span, concrete_type, indices));
|
|
}
|
|
} else {
|
|
debug!(
|
|
"find_opaque_ty_constraints: no constraint for `{:?}` at `{:?}`",
|
|
self.def_id, def_id,
|
|
);
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'tcx> intravisit::Visitor<'tcx> for ConstraintLocator<'tcx> {
|
|
fn nested_visit_map<'this>(&'this mut self) -> intravisit::NestedVisitorMap<'this, 'tcx> {
|
|
intravisit::NestedVisitorMap::All(&self.tcx.hir())
|
|
}
|
|
fn visit_item(&mut self, it: &'tcx Item<'tcx>) {
|
|
debug!("find_existential_constraints: visiting {:?}", it);
|
|
let def_id = self.tcx.hir().local_def_id(it.hir_id);
|
|
// The opaque type itself or its children are not within its reveal scope.
|
|
if def_id != self.def_id {
|
|
self.check(def_id);
|
|
intravisit::walk_item(self, it);
|
|
}
|
|
}
|
|
fn visit_impl_item(&mut self, it: &'tcx ImplItem<'tcx>) {
|
|
debug!("find_existential_constraints: visiting {:?}", it);
|
|
let def_id = self.tcx.hir().local_def_id(it.hir_id);
|
|
// The opaque type itself or its children are not within its reveal scope.
|
|
if def_id != self.def_id {
|
|
self.check(def_id);
|
|
intravisit::walk_impl_item(self, it);
|
|
}
|
|
}
|
|
fn visit_trait_item(&mut self, it: &'tcx TraitItem<'tcx>) {
|
|
debug!("find_existential_constraints: visiting {:?}", it);
|
|
let def_id = self.tcx.hir().local_def_id(it.hir_id);
|
|
self.check(def_id);
|
|
intravisit::walk_trait_item(self, it);
|
|
}
|
|
}
|
|
|
|
let hir_id = tcx.hir().as_local_hir_id(def_id).unwrap();
|
|
let scope = tcx.hir().get_defining_scope(hir_id);
|
|
let mut locator = ConstraintLocator { def_id, tcx, found: None };
|
|
|
|
debug!("find_opaque_ty_constraints: scope={:?}", scope);
|
|
|
|
if scope == hir::CRATE_HIR_ID {
|
|
intravisit::walk_crate(&mut locator, tcx.hir().krate());
|
|
} else {
|
|
debug!("find_opaque_ty_constraints: scope={:?}", tcx.hir().get(scope));
|
|
match tcx.hir().get(scope) {
|
|
// We explicitly call `visit_*` methods, instead of using `intravisit::walk_*` methods
|
|
// This allows our visitor to process the defining item itself, causing
|
|
// it to pick up any 'sibling' defining uses.
|
|
//
|
|
// For example, this code:
|
|
// ```
|
|
// fn foo() {
|
|
// type Blah = impl Debug;
|
|
// let my_closure = || -> Blah { true };
|
|
// }
|
|
// ```
|
|
//
|
|
// requires us to explicitly process `foo()` in order
|
|
// to notice the defining usage of `Blah`.
|
|
Node::Item(ref it) => locator.visit_item(it),
|
|
Node::ImplItem(ref it) => locator.visit_impl_item(it),
|
|
Node::TraitItem(ref it) => locator.visit_trait_item(it),
|
|
other => bug!("{:?} is not a valid scope for an opaque type item", other),
|
|
}
|
|
}
|
|
|
|
match locator.found {
|
|
Some((_, ty, _)) => ty,
|
|
None => {
|
|
let span = tcx.def_span(def_id);
|
|
tcx.sess.span_err(span, "could not find defining uses");
|
|
tcx.types.err
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Whether `ty` is a type with `_` placeholders that can be infered. 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 {
|
|
match &ty.kind {
|
|
hir::TyKind::Infer => true,
|
|
hir::TyKind::Slice(ty) | hir::TyKind::Array(ty, _) => is_suggestable_infer_ty(ty),
|
|
hir::TyKind::Tup(tys) => tys.iter().any(|ty| is_suggestable_infer_ty(ty)),
|
|
_ => false,
|
|
}
|
|
}
|
|
|
|
pub fn get_infer_ret_ty(output: &'hir hir::FunctionRetTy<'hir>) -> Option<&'hir hir::Ty<'hir>> {
|
|
if let hir::FunctionRetTy::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::Method(sig, TraitMethod::Provided(_)),
|
|
ident,
|
|
generics,
|
|
..
|
|
})
|
|
| ImplItem(hir::ImplItem { kind: ImplItemKind::Method(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.params[..],
|
|
Some(ident.span),
|
|
),
|
|
}
|
|
}
|
|
|
|
TraitItem(hir::TraitItem {
|
|
kind: TraitItemKind::Method(FnSig { header, decl }, _),
|
|
ident,
|
|
generics,
|
|
..
|
|
}) => AstConv::ty_of_fn(
|
|
&icx,
|
|
header.unsafety,
|
|
header.abi,
|
|
decl,
|
|
&generics.params[..],
|
|
Some(ident.span),
|
|
),
|
|
|
|
ForeignItem(&hir::ForeignItem { kind: ForeignItemKind::Fn(ref fn_decl, _, _), .. }) => {
|
|
let abi = tcx.hir().get_foreign_abi(hir_id);
|
|
compute_sig_of_foreign_fn_decl(tcx, def_id, fn_decl, abi)
|
|
}
|
|
|
|
Ctor(data) | Variant(hir::Variant { data, .. }) if data.ctor_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
|
|
// `closure_sig` method on the `ClosureSubsts`:
|
|
//
|
|
// closure_substs.sig(def_id, tcx)
|
|
//
|
|
// or, inside of an inference context, you can use
|
|
//
|
|
// infcx.closure_sig(def_id, closure_substs)
|
|
bug!("to get the signature of a closure, use `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 opt_trait_ref, _, _) => {
|
|
opt_trait_ref.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(_, hir::ImplPolarity::Negative, ..) => {
|
|
if is_rustc_reservation {
|
|
tcx.sess.span_err(item.span, "reservation impls can't be negative");
|
|
}
|
|
ty::ImplPolarity::Negative
|
|
}
|
|
hir::ItemKind::Impl(_, hir::ImplPolarity::Positive, _, _, None, _, _) => {
|
|
if is_rustc_reservation {
|
|
tcx.sess.span_err(item.span, "reservation impls can't be inherent");
|
|
}
|
|
ty::ImplPolarity::Positive
|
|
}
|
|
hir::ItemKind::Impl(_, hir::ImplPolarity::Positive, _, _, Some(_tr), _, _) => {
|
|
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).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_data_structures::fx::FxHashSet;
|
|
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);
|
|
|
|
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().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 predicate = ty::OutlivesPredicate(ty, tcx.mk_region(ty::ReEmpty));
|
|
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, _) => {
|
|
let mut bounds = Bounds::default();
|
|
let _ = AstConv::instantiate_poly_trait_ref(
|
|
&icx,
|
|
poly_trait_ref,
|
|
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 https://github.com/rust-lang/rust/issues/44265")
|
|
.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>,
|
|
) -> Vec<(ty::Predicate<'tcx>, Span)> {
|
|
match *bound {
|
|
hir::GenericBound::Trait(ref tr, hir::TraitBoundModifier::None) => {
|
|
let mut bounds = Bounds::default();
|
|
let _ = astconv.instantiate_poly_trait_ref(tr, 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)]
|
|
}
|
|
hir::GenericBound::Trait(_, hir::TraitBoundModifier::Maybe) => vec![],
|
|
}
|
|
}
|
|
|
|
fn compute_sig_of_foreign_fn_decl<'tcx>(
|
|
tcx: TyCtxt<'tcx>,
|
|
def_id: DefId,
|
|
decl: &'tcx hir::FnDecl<'tcx>,
|
|
abi: abi::Abi,
|
|
) -> ty::PolyFnSig<'tcx> {
|
|
let unsafety = if abi == abi::Abi::RustIntrinsic {
|
|
intrinsic_operation_unsafety(&tcx.item_name(def_id).as_str())
|
|
} else {
|
|
hir::Unsafety::Unsafe
|
|
};
|
|
let fty = AstConv::ty_of_fn(&ItemCtxt::new(tcx, def_id), unsafety, abi, decl, &[], 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() {
|
|
tcx.sess
|
|
.struct_span_err(
|
|
ast_ty.span,
|
|
&format!(
|
|
"use of SIMD type `{}` in FFI is highly experimental and \
|
|
may result in invalid code",
|
|
tcx.hir().hir_to_pretty_string(ast_ty.hir_id)
|
|
),
|
|
)
|
|
.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::FunctionRetTy::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 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().map(|s| *s) {
|
|
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_gate::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::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();
|
|
|
|
let whitelist = tcx.target_features_whitelist(LOCAL_CRATE);
|
|
|
|
let mut inline_span = None;
|
|
let mut link_ordinal_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::no_debug) {
|
|
codegen_fn_attrs.flags |= CodegenFnAttrFlags::NO_DEBUG;
|
|
} 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.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.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;
|
|
}
|
|
}
|
|
}
|
|
|
|
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.len() > 0 {
|
|
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]`",
|
|
);
|
|
}
|
|
}
|
|
}
|
|
|
|
// 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
|
|
}
|
|
|
|
fn check_link_ordinal(tcx: TyCtxt<'_>, attr: &ast::Attribute) -> Option<usize> {
|
|
use syntax::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);
|
|
}
|
|
}
|