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Rollup merge of #118396 - compiler-errors:ast-lang-items, r=cjgillot

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Collect lang items from AST, get rid of `GenericBound::LangItemTrait`

r? `@cjgillot`
cc #115178

Looking forward, the work to remove `QPath::LangItem` will also be significantly more difficult, but I plan on doing it as well. Specifically, we have to change:
1. A lot of `rustc_ast_lowering` for things like expr `..`
2. A lot of astconv, since we actually instantiate lang and non-lang paths quite differently.
3. A ton of diagnostics and clippy lints that are special-cased via `QPath::LangItem`

Meanwhile, it was pretty easy to remove `GenericBound::LangItemTrait`, so I just did that here.
This commit is contained in:
Jubilee 2023-12-15 14:08:15 -08:00 • committed by GitHub
commit 1d54949765
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GPG key ID: 4AEE18F83AFDEB23
31 changed files with 504 additions and 412 deletions
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22
compiler/rustc_ast/src/ast.rs
View file

@ -2845,6 +2845,28 @@ impl Item {
pub fn span_with_attributes(&self) -> Span {
self.attrs.iter().fold(self.span, |acc, attr| acc.to(attr.span))
}
pub fn opt_generics(&self) -> Option<&Generics> {
match &self.kind {
ItemKind::ExternCrate(_)
| ItemKind::Use(_)
| ItemKind::Mod(_, _)
| ItemKind::ForeignMod(_)
| ItemKind::GlobalAsm(_)
| ItemKind::MacCall(_)
| ItemKind::MacroDef(_) => None,
ItemKind::Static(_) => None,
ItemKind::Const(i) => Some(&i.generics),
ItemKind::Fn(i) => Some(&i.generics),
ItemKind::TyAlias(i) => Some(&i.generics),
ItemKind::TraitAlias(generics, _)
| ItemKind::Enum(_, generics)
| ItemKind::Struct(_, generics)
| ItemKind::Union(_, generics) => Some(&generics),
ItemKind::Trait(i) => Some(&i.generics),
ItemKind::Impl(i) => Some(&i.generics),
}
}
}
/// `extern` qualifier on a function item or function type.

44
compiler/rustc_ast_lowering/src/lib.rs
View file

@ -453,6 +453,7 @@ pub fn lower_to_hir(tcx: TyCtxt<'_>, (): ()) -> hir::Crate<'_> {
tcx.ensure_with_value().output_filenames(());
tcx.ensure_with_value().early_lint_checks(());
tcx.ensure_with_value().debugger_visualizers(LOCAL_CRATE);
tcx.ensure_with_value().get_lang_items(());
let (mut resolver, krate) = tcx.resolver_for_lowering(()).steal();
let ast_index = index_crate(&resolver.node_id_to_def_id, &krate);
@ -765,6 +766,28 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
self.resolver.get_import_res(id).present_items()
}
fn make_lang_item_path(
&mut self,
lang_item: hir::LangItem,
span: Span,
args: Option<&'hir hir::GenericArgs<'hir>>,
) -> &'hir hir::Path<'hir> {
let def_id = self.tcx.require_lang_item(lang_item, Some(span));
let def_kind = self.tcx.def_kind(def_id);
let res = Res::Def(def_kind, def_id);
self.arena.alloc(hir::Path {
span,
res,
segments: self.arena.alloc_from_iter([hir::PathSegment {
ident: Ident::new(lang_item.name(), span),
hir_id: self.next_id(),
res,
args,
infer_args: false,
}]),
})
}
/// Reuses the span but adds information like the kind of the desugaring and features that are
/// allowed inside this span.
fn mark_span_with_reason(
@ -1976,18 +1999,27 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
CoroutineKind::AsyncGen { .. } => (sym::Item, hir::LangItem::AsyncIterator),
};
let future_args = self.arena.alloc(hir::GenericArgs {
let bound_args = self.arena.alloc(hir::GenericArgs {
args: &[],
bindings: arena_vec![self; self.assoc_ty_binding(assoc_ty_name, opaque_ty_span, output_ty)],
parenthesized: hir::GenericArgsParentheses::No,
span_ext: DUMMY_SP,
});
hir::GenericBound::LangItemTrait(
trait_lang_item,
opaque_ty_span,
self.next_id(),
future_args,
hir::GenericBound::Trait(
hir::PolyTraitRef {
bound_generic_params: &[],
trait_ref: hir::TraitRef {
path: self.make_lang_item_path(
trait_lang_item,
opaque_ty_span,
Some(bound_args),
),
hir_ref_id: self.next_id(),
},
span: opaque_ty_span,
},
hir::TraitBoundModifier::None,
)
}

30
compiler/rustc_borrowck/src/diagnostics/region_name.rs
View file

@ -788,28 +788,18 @@ impl<'tcx> MirBorrowckCtxt<'_, 'tcx> {
};
let opaque_ty = hir.item(id);
if let hir::ItemKind::OpaqueTy(hir::OpaqueTy {
bounds:
[
hir::GenericBound::LangItemTrait(
hir::LangItem::Future,
_,
_,
hir::GenericArgs {
bindings:
[
hir::TypeBinding {
ident: Ident { name: sym::Output, .. },
kind:
hir::TypeBindingKind::Equality { term: hir::Term::Ty(ty) },
..
},
],
..
},
),
],
bounds: [hir::GenericBound::Trait(trait_ref, _)],
..
}) = opaque_ty.kind
&& let Some(segment) = trait_ref.trait_ref.path.segments.last()
&& let Some(args) = segment.args
&& let [
hir::TypeBinding {
ident: Ident { name: sym::Output, .. },
kind: hir::TypeBindingKind::Equality { term: hir::Term::Ty(ty) },
..
},
] = args.bindings
{
ty
} else {

3
compiler/rustc_hir/src/hir.rs
View file

@ -435,8 +435,6 @@ pub enum TraitBoundModifier {
#[derive(Clone, Copy, Debug, HashStable_Generic)]
pub enum GenericBound<'hir> {
Trait(PolyTraitRef<'hir>, TraitBoundModifier),
// FIXME(davidtwco): Introduce `PolyTraitRef::LangItem`
LangItemTrait(LangItem, Span, HirId, &'hir GenericArgs<'hir>),
Outlives(&'hir Lifetime),
}
@ -451,7 +449,6 @@ impl GenericBound<'_> {
pub fn span(&self) -> Span {
match self {
GenericBound::Trait(t, ..) => t.span,
GenericBound::LangItemTrait(_, span, ..) => *span,
GenericBound::Outlives(l) => l.ident.span,
}
}

4
compiler/rustc_hir/src/intravisit.rs
View file

@ -1075,10 +1075,6 @@ pub fn walk_param_bound<'v, V: Visitor<'v>>(visitor: &mut V, bound: &'v GenericB
GenericBound::Trait(ref typ, _modifier) => {
visitor.visit_poly_trait_ref(typ);
}
GenericBound::LangItemTrait(_, _span, hir_id, args) => {
visitor.visit_id(hir_id);
visitor.visit_generic_args(args);
}
GenericBound::Outlives(ref lifetime) => visitor.visit_lifetime(lifetime),
}
}

36
compiler/rustc_hir/src/target.rs
View file

@ -67,6 +67,42 @@ impl Display for Target {
}
impl Target {
pub fn is_associated_item(self) -> bool {
match self {
Target::AssocConst | Target::AssocTy | Target::Method(_) => true,
Target::ExternCrate
| Target::Use
| Target::Static
| Target::Const
| Target::Fn
| Target::Closure
| Target::Mod
| Target::ForeignMod
| Target::GlobalAsm
| Target::TyAlias
| Target::OpaqueTy
| Target::Enum
| Target::Variant
| Target::Struct
| Target::Field
| Target::Union
| Target::Trait
| Target::TraitAlias
| Target::Impl
| Target::Expression
| Target::Statement
| Target::Arm
| Target::ForeignFn
| Target::ForeignStatic
| Target::ForeignTy
| Target::GenericParam(_)
| Target::MacroDef
| Target::Param
| Target::PatField
| Target::ExprField => false,
}
}
pub fn from_item(item: &Item<'_>) -> Target {
match item.kind {
ItemKind::ExternCrate(..) => Target::ExternCrate,

11
compiler/rustc_hir_analysis/src/astconv/bounds.rs
View file

@ -134,17 +134,6 @@ impl<'tcx> dyn AstConv<'tcx> + '_ {
only_self_bounds,
);
}
&hir::GenericBound::LangItemTrait(lang_item, span, hir_id, args) => {
self.instantiate_lang_item_trait_ref(
lang_item,
span,
hir_id,
args,
param_ty,
bounds,
only_self_bounds,
);
}
hir::GenericBound::Outlives(lifetime) => {
let region = self.ast_region_to_region(lifetime, None);
bounds.push_region_bound(

145
compiler/rustc_hir_analysis/src/astconv/mod.rs
View file

@ -678,36 +678,57 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
)
}
fn instantiate_poly_trait_ref_inner(
/// Given a trait bound like `Debug`, applies that trait bound the given self-type to construct
/// a full trait reference. The resulting trait reference is returned. This may also generate
/// auxiliary bounds, which are added to `bounds`.
///
/// Example:
///
/// ```ignore (illustrative)
/// poly_trait_ref = Iterator<Item = u32>
/// self_ty = Foo
/// ```
///
/// this would return `Foo: Iterator` and add `<Foo as Iterator>::Item = u32` into `bounds`.
///
/// **A note on binders:** against our usual convention, there is an implied binder around
/// the `self_ty` and `poly_trait_ref` parameters here. So they may reference bound regions.
/// If for example you had `for<'a> Foo<'a>: Bar<'a>`, then the `self_ty` would be `Foo<'a>`
/// where `'a` is a bound region at depth 0. Similarly, the `poly_trait_ref` would be
/// `Bar<'a>`. The returned poly-trait-ref will have this binder instantiated explicitly,
/// however.
#[instrument(level = "debug", skip(self, span, constness, bounds, speculative))]
pub(crate) fn instantiate_poly_trait_ref(
&self,
hir_id: hir::HirId,
trait_ref: &hir::TraitRef<'_>,
span: Span,
binding_span: Option<Span>,
constness: ty::BoundConstness,
polarity: ty::ImplPolarity,
self_ty: Ty<'tcx>,
bounds: &mut Bounds<'tcx>,
speculative: bool,
trait_ref_span: Span,
trait_def_id: DefId,
trait_segment: &hir::PathSegment<'_>,
args: &GenericArgs<'_>,
infer_args: bool,
self_ty: Ty<'tcx>,
only_self_bounds: OnlySelfBounds,
) -> GenericArgCountResult {
let trait_def_id = trait_ref.trait_def_id().unwrap_or_else(|| FatalError.raise());
let trait_segment = trait_ref.path.segments.last().unwrap();
let args = trait_segment.args();
self.prohibit_generics(trait_ref.path.segments.split_last().unwrap().1.iter(), |_| {});
self.complain_about_internal_fn_trait(span, trait_def_id, trait_segment, false);
let (generic_args, arg_count) = self.create_args_for_ast_path(
trait_ref_span,
trait_ref.path.span,
trait_def_id,
&[],
trait_segment,
args,
infer_args,
trait_segment.infer_args,
Some(self_ty),
constness,
);
let tcx = self.tcx();
let bound_vars = tcx.late_bound_vars(hir_id);
let bound_vars = tcx.late_bound_vars(trait_ref.hir_ref_id);
debug!(?bound_vars);
let assoc_bindings = self.create_assoc_bindings_for_generic_args(args);
@ -735,13 +756,13 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
// Specify type to assert that error was already reported in `Err` case.
let _: Result<_, ErrorGuaranteed> = self.add_predicates_for_ast_type_binding(
hir_id,
trait_ref.hir_ref_id,
poly_trait_ref,
binding,
bounds,
speculative,
&mut dup_bindings,
binding_span.unwrap_or(binding.span),
binding.span,
constness,
only_self_bounds,
polarity,
@ -752,102 +773,6 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
arg_count
}
/// Given a trait bound like `Debug`, applies that trait bound the given self-type to construct
/// a full trait reference. The resulting trait reference is returned. This may also generate
/// auxiliary bounds, which are added to `bounds`.
///
/// Example:
///
/// ```ignore (illustrative)
/// poly_trait_ref = Iterator<Item = u32>
/// self_ty = Foo
/// ```
///
/// this would return `Foo: Iterator` and add `<Foo as Iterator>::Item = u32` into `bounds`.
///
/// **A note on binders:** against our usual convention, there is an implied bounder around
/// the `self_ty` and `poly_trait_ref` parameters here. So they may reference bound regions.
/// If for example you had `for<'a> Foo<'a>: Bar<'a>`, then the `self_ty` would be `Foo<'a>`
/// where `'a` is a bound region at depth 0. Similarly, the `poly_trait_ref` would be
/// `Bar<'a>`. The returned poly-trait-ref will have this binder instantiated explicitly,
/// however.
#[instrument(level = "debug", skip(self, span, constness, bounds, speculative))]
pub(crate) fn instantiate_poly_trait_ref(
&self,
trait_ref: &hir::TraitRef<'_>,
span: Span,
constness: ty::BoundConstness,
polarity: ty::ImplPolarity,
self_ty: Ty<'tcx>,
bounds: &mut Bounds<'tcx>,
speculative: bool,
only_self_bounds: OnlySelfBounds,
) -> GenericArgCountResult {
let hir_id = trait_ref.hir_ref_id;
let binding_span = None;
let trait_ref_span = trait_ref.path.span;
let trait_def_id = trait_ref.trait_def_id().unwrap_or_else(|| FatalError.raise());
let trait_segment = trait_ref.path.segments.last().unwrap();
let args = trait_segment.args();
let infer_args = trait_segment.infer_args;
self.prohibit_generics(trait_ref.path.segments.split_last().unwrap().1.iter(), |_| {});
self.complain_about_internal_fn_trait(span, trait_def_id, trait_segment, false);
self.instantiate_poly_trait_ref_inner(
hir_id,
span,
binding_span,
constness,
polarity,
bounds,
speculative,
trait_ref_span,
trait_def_id,
trait_segment,
args,
infer_args,
self_ty,
only_self_bounds,
)
}
pub(crate) fn instantiate_lang_item_trait_ref(
&self,
lang_item: hir::LangItem,
span: Span,
hir_id: hir::HirId,
args: &GenericArgs<'_>,
self_ty: Ty<'tcx>,
bounds: &mut Bounds<'tcx>,
only_self_bounds: OnlySelfBounds,
) {
let binding_span = Some(span);
let constness = ty::BoundConstness::NotConst;
let speculative = false;
let trait_ref_span = span;
let trait_def_id = self.tcx().require_lang_item(lang_item, Some(span));
let trait_segment = &hir::PathSegment::invalid();
let infer_args = false;
self.instantiate_poly_trait_ref_inner(
hir_id,
span,
binding_span,
constness,
ty::ImplPolarity::Positive,
bounds,
speculative,
trait_ref_span,
trait_def_id,
trait_segment,
args,
infer_args,
self_ty,
only_self_bounds,
);
}
fn ast_path_to_mono_trait_ref(
&self,
span: Span,

26
compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs
View file

@ -938,32 +938,6 @@ impl<'a, 'tcx> Visitor<'tcx> for BoundVarContext<'a, 'tcx> {
}
}
fn visit_param_bound(&mut self, bound: &'tcx hir::GenericBound<'tcx>) {
match bound {
hir::GenericBound::LangItemTrait(_, _, hir_id, _) => {
// FIXME(jackh726): This is pretty weird. `LangItemTrait` doesn't go
// through the regular poly trait ref code, so we don't get another
// chance to introduce a binder. For now, I'm keeping the existing logic
// of "if there isn't a Binder scope above us, add one", but I
// imagine there's a better way to go about this.
let (binders, scope_type) = self.poly_trait_ref_binder_info();
self.record_late_bound_vars(*hir_id, binders);
let scope = Scope::Binder {
hir_id: *hir_id,
bound_vars: FxIndexMap::default(),
s: self.scope,
scope_type,
where_bound_origin: None,
};
self.with(scope, |this| {
intravisit::walk_param_bound(this, bound);
});
}
_ => intravisit::walk_param_bound(self, bound),
}
}
fn visit_poly_trait_ref(&mut self, trait_ref: &'tcx hir::PolyTraitRef<'tcx>) {
self.visit_poly_trait_ref_inner(trait_ref, NonLifetimeBinderAllowed::Allow);
}

5
compiler/rustc_hir_pretty/src/lib.rs
View file

@ -2084,11 +2084,6 @@ impl<'a> State<'a> {
}
self.print_poly_trait_ref(tref);
}
GenericBound::LangItemTrait(lang_item, span, ..) => {
self.word("#[lang = \"");
self.print_ident(Ident::new(lang_item.name(), *span));
self.word("\"]");
}
GenericBound::Outlives(lt) => {
self.print_lifetime(lt);
}

6
compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs
View file

@ -825,9 +825,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
&& let hir::Node::Item(hir::Item {
kind: hir::ItemKind::OpaqueTy(op_ty), ..
}) = self.tcx.hir_node(item_id.hir_id())
&& let [
hir::GenericBound::LangItemTrait(hir::LangItem::Future, _, _, generic_args),
] = op_ty.bounds
&& let [hir::GenericBound::Trait(trait_ref, _)] = op_ty.bounds
&& let Some(hir::PathSegment { args: Some(generic_args), .. }) =
trait_ref.trait_ref.path.segments.last()
&& let hir::GenericArgs { bindings: [ty_binding], .. } = generic_args
&& let hir::TypeBindingKind::Equality { term: hir::Term::Ty(term) } =
ty_binding.kind

26
compiler/rustc_infer/src/infer/error_reporting/suggest.rs
View file

@ -668,26 +668,16 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
(
hir::ItemKind::OpaqueTy(hir::OpaqueTy { bounds: last_bounds, .. }),
hir::ItemKind::OpaqueTy(hir::OpaqueTy { bounds: exp_bounds, .. }),
) if std::iter::zip(*last_bounds, *exp_bounds).all(|(left, right)| {
match (left, right) {
(
hir::GenericBound::Trait(tl, ml),
hir::GenericBound::Trait(tr, mr),
) if tl.trait_ref.trait_def_id() == tr.trait_ref.trait_def_id()
) if std::iter::zip(*last_bounds, *exp_bounds).all(|(left, right)| match (
left, right,
) {
(hir::GenericBound::Trait(tl, ml), hir::GenericBound::Trait(tr, mr))
if tl.trait_ref.trait_def_id() == tr.trait_ref.trait_def_id()
&& ml == mr =>
{
true
}
(
hir::GenericBound::LangItemTrait(langl, _, _, argsl),
hir::GenericBound::LangItemTrait(langr, _, _, argsr),
) if langl == langr => {
// FIXME: consider the bounds!
debug!("{:?} {:?}", argsl, argsr);
true
}
_ => false,
{
true
}
_ => false,
}) =>
{
StatementAsExpression::NeedsBoxing

2
compiler/rustc_passes/src/hir_stats.rs
View file

@ -429,7 +429,7 @@ impl<'v> hir_visit::Visitor<'v> for StatCollector<'v> {
fn visit_param_bound(&mut self, b: &'v hir::GenericBound<'v>) {
record_variants!(
(self, b, b, Id::None, hir, GenericBound, GenericBound),
[Trait, LangItemTrait, Outlives]
[Trait, Outlives]
);
hir_visit::walk_param_bound(self, b)
}

388
compiler/rustc_passes/src/lang_items.rs
View file

@ -7,18 +7,18 @@
//! * Traits that represent operators; e.g., `Add`, `Sub`, `Index`.
//! * Functions called by the compiler itself.
use crate::check_attr::target_from_impl_item;
use crate::errors::{
DuplicateLangItem, IncorrectTarget, LangItemOnIncorrectTarget, UnknownLangItem,
};
use crate::weak_lang_items;
use rustc_hir as hir;
use rustc_hir::def::DefKind;
use rustc_ast as ast;
use rustc_ast::visit;
use rustc_data_structures::fx::FxHashMap;
use rustc_hir::def_id::{DefId, LocalDefId};
use rustc_hir::lang_items::{extract, GenericRequirement};
use rustc_hir::{LangItem, LanguageItems, Target};
use rustc_middle::ty::TyCtxt;
use rustc_hir::{LangItem, LanguageItems, MethodKind, Target};
use rustc_middle::ty::{ResolverAstLowering, TyCtxt};
use rustc_session::cstore::ExternCrate;
use rustc_span::symbol::kw::Empty;
use rustc_span::Span;
@ -31,28 +31,55 @@ pub(crate) enum Duplicate {
CrateDepends,
}
struct LanguageItemCollector<'tcx> {
struct LanguageItemCollector<'ast, 'tcx> {
items: LanguageItems,
tcx: TyCtxt<'tcx>,
resolver: &'ast ResolverAstLowering,
// FIXME(#118552): We should probably feed def_span eagerly on def-id creation
// so we can avoid constructing this map for local def-ids.
item_spans: FxHashMap<DefId, Span>,
parent_item: Option<&'ast ast::Item>,
}
impl<'tcx> LanguageItemCollector<'tcx> {
fn new(tcx: TyCtxt<'tcx>) -> LanguageItemCollector<'tcx> {
LanguageItemCollector { tcx, items: LanguageItems::new() }
impl<'ast, 'tcx> LanguageItemCollector<'ast, 'tcx> {
fn new(
tcx: TyCtxt<'tcx>,
resolver: &'ast ResolverAstLowering,
) -> LanguageItemCollector<'ast, 'tcx> {
LanguageItemCollector {
tcx,
resolver,
items: LanguageItems::new(),
item_spans: FxHashMap::default(),
parent_item: None,
}
}
fn check_for_lang(&mut self, actual_target: Target, def_id: LocalDefId) {
let attrs = self.tcx.hir().attrs(self.tcx.local_def_id_to_hir_id(def_id));
if let Some((name, span)) = extract(attrs) {
fn check_for_lang(
&mut self,
actual_target: Target,
def_id: LocalDefId,
attrs: &'ast [ast::Attribute],
item_span: Span,
generics: Option<&'ast ast::Generics>,
) {
if let Some((name, attr_span)) = extract(attrs) {
match LangItem::from_name(name) {
// Known lang item with attribute on correct target.
Some(lang_item) if actual_target == lang_item.target() => {
self.collect_item_extended(lang_item, def_id, span);
self.collect_item_extended(
lang_item,
def_id,
item_span,
attr_span,
generics,
actual_target,
);
}
// Known lang item with attribute on incorrect target.
Some(lang_item) => {
self.tcx.sess.emit_err(LangItemOnIncorrectTarget {
span,
span: attr_span,
name,
expected_target: lang_item.target(),
actual_target,
@ -60,127 +87,131 @@ impl<'tcx> LanguageItemCollector<'tcx> {
}
// Unknown lang item.
_ => {
self.tcx.sess.emit_err(UnknownLangItem { span, name });
self.tcx.sess.emit_err(UnknownLangItem { span: attr_span, name });
}
}
}
}
fn collect_item(&mut self, lang_item: LangItem, item_def_id: DefId) {
fn collect_item(&mut self, lang_item: LangItem, item_def_id: DefId, item_span: Option<Span>) {
// Check for duplicates.
if let Some(original_def_id) = self.items.get(lang_item) {
if original_def_id != item_def_id {
let local_span = self.tcx.hir().span_if_local(item_def_id);
let lang_item_name = lang_item.name();
let crate_name = self.tcx.crate_name(item_def_id.krate);
let mut dependency_of = Empty;
let is_local = item_def_id.is_local();
let path = if is_local {
String::new()
} else {
self.tcx
.crate_extern_paths(item_def_id.krate)
.iter()
.map(|p| p.display().to_string())
.collect::<Vec<_>>()
.join(", ")
};
let first_defined_span = self.tcx.hir().span_if_local(original_def_id);
let mut orig_crate_name = Empty;
let mut orig_dependency_of = Empty;
let orig_is_local = original_def_id.is_local();
let orig_path = if orig_is_local {
String::new()
} else {
self.tcx
.crate_extern_paths(original_def_id.krate)
.iter()
.map(|p| p.display().to_string())
.collect::<Vec<_>>()
.join(", ")
};
if first_defined_span.is_none() {
orig_crate_name = self.tcx.crate_name(original_def_id.krate);
if let Some(ExternCrate { dependency_of: inner_dependency_of, .. }) =
self.tcx.extern_crate(original_def_id)
{
orig_dependency_of = self.tcx.crate_name(*inner_dependency_of);
}
if let Some(original_def_id) = self.items.get(lang_item)
&& original_def_id != item_def_id
{
let lang_item_name = lang_item.name();
let crate_name = self.tcx.crate_name(item_def_id.krate);
let mut dependency_of = Empty;
let is_local = item_def_id.is_local();
let path = if is_local {
String::new()
} else {
self.tcx
.crate_extern_paths(item_def_id.krate)
.iter()
.map(|p| p.display().to_string())
.collect::<Vec<_>>()
.join(", ")
};
let first_defined_span = self.item_spans.get(&original_def_id).copied();
let mut orig_crate_name = Empty;
let mut orig_dependency_of = Empty;
let orig_is_local = original_def_id.is_local();
let orig_path = if orig_is_local {
String::new()
} else {
self.tcx
.crate_extern_paths(original_def_id.krate)
.iter()
.map(|p| p.display().to_string())
.collect::<Vec<_>>()
.join(", ")
};
if first_defined_span.is_none() {
orig_crate_name = self.tcx.crate_name(original_def_id.krate);
if let Some(ExternCrate { dependency_of: inner_dependency_of, .. }) =
self.tcx.extern_crate(original_def_id)
{
orig_dependency_of = self.tcx.crate_name(*inner_dependency_of);
}
}
let duplicate = if local_span.is_some() {
Duplicate::Plain
} else {
match self.tcx.extern_crate(item_def_id) {
Some(ExternCrate { dependency_of: inner_dependency_of, .. }) => {
dependency_of = self.tcx.crate_name(*inner_dependency_of);
Duplicate::CrateDepends
}
_ => Duplicate::Crate,
let duplicate = if item_span.is_some() {
Duplicate::Plain
} else {
match self.tcx.extern_crate(item_def_id) {
Some(ExternCrate { dependency_of: inner_dependency_of, .. }) => {
dependency_of = self.tcx.crate_name(*inner_dependency_of);
Duplicate::CrateDepends
}
};
_ => Duplicate::Crate,
}
};
self.tcx.sess.emit_err(DuplicateLangItem {
local_span,
lang_item_name,
crate_name,
dependency_of,
is_local,
path,
first_defined_span,
orig_crate_name,
orig_dependency_of,
orig_is_local,
orig_path,
duplicate,
});
self.tcx.sess.emit_err(DuplicateLangItem {
local_span: item_span,
lang_item_name,
crate_name,
dependency_of,
is_local,
path,
first_defined_span,
orig_crate_name,
orig_dependency_of,
orig_is_local,
orig_path,
duplicate,
});
} else {
// Matched.
self.items.set(lang_item, item_def_id);
// Collect span for error later
if let Some(item_span) = item_span {
self.item_spans.insert(item_def_id, item_span);
}
}
// Matched.
self.items.set(lang_item, item_def_id);
}
// Like collect_item() above, but also checks whether the lang item is declared
// with the right number of generic arguments.
fn collect_item_extended(&mut self, lang_item: LangItem, item_def_id: LocalDefId, span: Span) {
fn collect_item_extended(
&mut self,
lang_item: LangItem,
item_def_id: LocalDefId,
item_span: Span,
attr_span: Span,
generics: Option<&'ast ast::Generics>,
target: Target,
) {
let name = lang_item.name();
// Now check whether the lang_item has the expected number of generic
// arguments. Generally speaking, binary and indexing operations have
// one (for the RHS/index), unary operations have none, the closure
// traits have one for the argument list, coroutines have one for the
// resume argument, and ordering/equality relations have one for the RHS
// Some other types like Box and various functions like drop_in_place
// have minimum requirements.
if let Some(generics) = generics {
// Now check whether the lang_item has the expected number of generic
// arguments. Generally speaking, binary and indexing operations have
// one (for the RHS/index), unary operations have none, the closure
// traits have one for the argument list, coroutines have one for the
// resume argument, and ordering/equality relations have one for the RHS
// Some other types like Box and various functions like drop_in_place
// have minimum requirements.
if let hir::Node::Item(hir::Item { kind, span: item_span, .. }) =
self.tcx.hir_node_by_def_id(item_def_id)
{
let (actual_num, generics_span) = match kind.generics() {
Some(generics) => (
generics
.params
.iter()
.filter(|p| {
!matches!(
p.kind,
hir::GenericParamKind::Const { is_host_effect: true, .. }
)
})
.count(),
generics.span,
),
None => (0, *item_span),
};
// FIXME: This still doesn't count, e.g., elided lifetimes and APITs.
let mut actual_num = generics.params.len();
if target.is_associated_item() {
actual_num += self
.parent_item
.unwrap()
.opt_generics()
.map_or(0, |generics| generics.params.len());
}
let mut at_least = false;
let required = match lang_item.required_generics() {
GenericRequirement::Exact(num) if num != actual_num => Some(num),
GenericRequirement::Minimum(num) if actual_num < num => {
at_least = true;
Some(num)}
,
Some(num)
}
// If the number matches, or there is no requirement, handle it normally
_ => None,
};
@ -190,10 +221,10 @@ impl<'tcx> LanguageItemCollector<'tcx> {
// item kind of the target is correct, the target is still wrong
// because of the wrong number of generic arguments.
self.tcx.sess.emit_err(IncorrectTarget {
span,
generics_span,
span: attr_span,
generics_span: generics.span,
name: name.as_str(),
kind: kind.descr(),
kind: target.name(),
num,
actual_num,
at_least,
@ -204,58 +235,117 @@ impl<'tcx> LanguageItemCollector<'tcx> {
}
}
self.collect_item(lang_item, item_def_id.to_def_id());
self.collect_item(lang_item, item_def_id.to_def_id(), Some(item_span));
}
}
/// Traverses and collects all the lang items in all crates.
fn get_lang_items(tcx: TyCtxt<'_>, (): ()) -> LanguageItems {
let resolver = tcx.resolver_for_lowering(()).borrow();
let (resolver, krate) = &*resolver;
// Initialize the collector.
let mut collector = LanguageItemCollector::new(tcx);
let mut collector = LanguageItemCollector::new(tcx, resolver);
// Collect lang items in other crates.
for &cnum in tcx.crates(()).iter() {
for &(def_id, lang_item) in tcx.defined_lang_items(cnum).iter() {
collector.collect_item(lang_item, def_id);
collector.collect_item(lang_item, def_id, None);
}
}
// Collect lang items in this crate.
let crate_items = tcx.hir_crate_items(());
for id in crate_items.items() {
collector
.check_for_lang(Target::from_def_kind(tcx.def_kind(id.owner_id)), id.owner_id.def_id);
if matches!(tcx.def_kind(id.owner_id), DefKind::Enum) {
let item = tcx.hir().item(id);
if let hir::ItemKind::Enum(def, ..) = &item.kind {
for variant in def.variants {
collector.check_for_lang(Target::Variant, variant.def_id);
}
}
}
}
// FIXME: avoid calling trait_item() when possible
for id in crate_items.trait_items() {
let item = tcx.hir().trait_item(id);
collector.check_for_lang(Target::from_trait_item(item), item.owner_id.def_id)
}
// FIXME: avoid calling impl_item() when possible
for id in crate_items.impl_items() {
let item = tcx.hir().impl_item(id);
collector.check_for_lang(target_from_impl_item(tcx, item), item.owner_id.def_id)
}
// Extract out the found lang items.
let LanguageItemCollector { mut items, .. } = collector;
// Collect lang items local to this crate.
visit::Visitor::visit_crate(&mut collector, krate);
// Find all required but not-yet-defined lang items.
weak_lang_items::check_crate(tcx, &mut items);
weak_lang_items::check_crate(tcx, &mut collector.items, krate);
items
// Return all the lang items that were found.
collector.items
}
impl<'ast, 'tcx> visit::Visitor<'ast> for LanguageItemCollector<'ast, 'tcx> {
fn visit_item(&mut self, i: &'ast ast::Item) {
let target = match &i.kind {
ast::ItemKind::ExternCrate(_) => Target::ExternCrate,
ast::ItemKind::Use(_) => Target::Use,
ast::ItemKind::Static(_) => Target::Static,
ast::ItemKind::Const(_) => Target::Const,
ast::ItemKind::Fn(_) => Target::Fn,
ast::ItemKind::Mod(_, _) => Target::Mod,
ast::ItemKind::ForeignMod(_) => Target::ForeignFn,
ast::ItemKind::GlobalAsm(_) => Target::GlobalAsm,
ast::ItemKind::TyAlias(_) => Target::TyAlias,
ast::ItemKind::Enum(_, _) => Target::Enum,
ast::ItemKind::Struct(_, _) => Target::Struct,
ast::ItemKind::Union(_, _) => Target::Union,
ast::ItemKind::Trait(_) => Target::Trait,
ast::ItemKind::TraitAlias(_, _) => Target::TraitAlias,
ast::ItemKind::Impl(_) => Target::Impl,
ast::ItemKind::MacroDef(_) => Target::MacroDef,
ast::ItemKind::MacCall(_) => unreachable!("macros should have been expanded"),
};
self.check_for_lang(
target,
self.resolver.node_id_to_def_id[&i.id],
&i.attrs,
i.span,
i.opt_generics(),
);
let parent_item = self.parent_item.replace(i);
visit::walk_item(self, i);
self.parent_item = parent_item;
}
fn visit_enum_def(&mut self, enum_definition: &'ast ast::EnumDef) {
for variant in &enum_definition.variants {
self.check_for_lang(
Target::Variant,
self.resolver.node_id_to_def_id[&variant.id],
&variant.attrs,
variant.span,
None,
);
}
visit::walk_enum_def(self, enum_definition);
}
fn visit_assoc_item(&mut self, i: &'ast ast::AssocItem, ctxt: visit::AssocCtxt) {
let (target, generics) = match &i.kind {
ast::AssocItemKind::Fn(fun) => (
match &self.parent_item.unwrap().kind {
ast::ItemKind::Impl(i) => {
if i.of_trait.is_some() {
Target::Method(MethodKind::Trait { body: fun.body.is_some() })
} else {
Target::Method(MethodKind::Inherent)
}
}
ast::ItemKind::Trait(_) => {
Target::Method(MethodKind::Trait { body: fun.body.is_some() })
}
_ => unreachable!(),
},
&fun.generics,
),
ast::AssocItemKind::Const(ct) => (Target::AssocConst, &ct.generics),
ast::AssocItemKind::Type(ty) => (Target::AssocTy, &ty.generics),
ast::AssocItemKind::MacCall(_) => unreachable!("macros should have been expanded"),
};
self.check_for_lang(
target,
self.resolver.node_id_to_def_id[&i.id],
&i.attrs,
i.span,
Some(generics),
);
visit::walk_assoc_item(self, i, ctxt);
}
}
pub fn provide(providers: &mut Providers) {

30
compiler/rustc_passes/src/weak_lang_items.rs
View file

@ -1,5 +1,7 @@
//! Validity checking for weak lang items
use rustc_ast as ast;
use rustc_ast::visit;
use rustc_data_structures::fx::FxHashSet;
use rustc_hir::lang_items::{self, LangItem};
use rustc_hir::weak_lang_items::WEAK_LANG_ITEMS;
@ -11,7 +13,7 @@ use crate::errors::{MissingLangItem, MissingPanicHandler, UnknownExternLangItem}
/// Checks the crate for usage of weak lang items, returning a vector of all the
/// language items required by this crate, but not defined yet.
pub fn check_crate(tcx: TyCtxt<'_>, items: &mut lang_items::LanguageItems) {
pub fn check_crate(tcx: TyCtxt<'_>, items: &mut lang_items::LanguageItems, krate: &ast::Crate) {
// These are never called by user code, they're generated by the compiler.
// They will never implicitly be added to the `missing` array unless we do
// so here.
@ -22,24 +24,30 @@ pub fn check_crate(tcx: TyCtxt<'_>, items: &mut lang_items::LanguageItems) {
items.missing.push(LangItem::EhCatchTypeinfo);
}
let crate_items = tcx.hir_crate_items(());
for id in crate_items.foreign_items() {
let attrs = tcx.hir().attrs(id.hir_id());
if let Some((lang_item, _)) = lang_items::extract(attrs) {
visit::Visitor::visit_crate(&mut WeakLangItemVisitor { tcx, items }, krate);
verify(tcx, items);
}
struct WeakLangItemVisitor<'a, 'tcx> {
tcx: TyCtxt<'tcx>,
items: &'a mut lang_items::LanguageItems,
}
impl<'ast> visit::Visitor<'ast> for WeakLangItemVisitor<'_, '_> {
fn visit_foreign_item(&mut self, i: &'ast ast::ForeignItem) {
if let Some((lang_item, _)) = lang_items::extract(&i.attrs) {
if let Some(item) = LangItem::from_name(lang_item)
&& item.is_weak()
{
if items.get(item).is_none() {
items.missing.push(item);
if self.items.get(item).is_none() {
self.items.missing.push(item);
}
} else {
let span = tcx.def_span(id.owner_id);
tcx.sess.emit_err(UnknownExternLangItem { span, lang_item });
self.tcx.sess.emit_err(UnknownExternLangItem { span: i.span, lang_item });
}
}
}
verify(tcx, items);
}
fn verify(tcx: TyCtxt<'_>, items: &lang_items::LanguageItems) {

10
compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
View file

@ -4783,8 +4783,14 @@ pub fn suggest_desugaring_async_fn_to_impl_future_in_trait<'tcx>(
};
let future = tcx.hir_node_by_def_id(opaque_def_id).expect_item().expect_opaque_ty();
let Some(hir::GenericBound::LangItemTrait(_, _, _, generics)) = future.bounds.get(0) else {
// `async fn` should always lower to a lang item bound... but don't ICE.
let [hir::GenericBound::Trait(trait_ref, _)] = future.bounds else {
// `async fn` should always lower to a single bound... but don't ICE.
return None;
};
let Some(hir::PathSegment { args: Some(generics), .. }) =
trait_ref.trait_ref.path.segments.last()
else {
// desugaring to a single path segment for `Future<...>`.
return None;
};
let Some(hir::TypeBindingKind::Equality { term: hir::Term::Ty(future_output_ty) }) =