diff options
Diffstat (limited to '')
| -rw-r--r-- | compiler/rustc_hir_analysis/src/check/check.rs (renamed from compiler/rustc_typeck/src/check/check.rs) | 588 |
1 files changed, 139 insertions, 449 deletions
diff --git a/compiler/rustc_typeck/src/check/check.rs b/compiler/rustc_hir_analysis/src/check/check.rs index d6fa74c87..b70ac0205 100644 --- a/compiler/rustc_typeck/src/check/check.rs +++ b/compiler/rustc_hir_analysis/src/check/check.rs @@ -1,8 +1,7 @@ use crate::check::intrinsicck::InlineAsmCtxt; -use super::coercion::CoerceMany; use super::compare_method::check_type_bounds; -use super::compare_method::{compare_const_impl, compare_impl_method, compare_ty_impl}; +use super::compare_method::{compare_impl_method, compare_ty_impl}; use super::*; use rustc_attr as attr; use rustc_errors::{Applicability, ErrorGuaranteed, MultiSpan}; @@ -10,10 +9,8 @@ use rustc_hir as hir; use rustc_hir::def::{DefKind, Res}; use rustc_hir::def_id::{DefId, LocalDefId}; use rustc_hir::intravisit::Visitor; -use rustc_hir::lang_items::LangItem; use rustc_hir::{ItemKind, Node, PathSegment}; use rustc_infer::infer::outlives::env::OutlivesEnvironment; -use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind}; use rustc_infer::infer::{DefiningAnchor, RegionVariableOrigin, TyCtxtInferExt}; use rustc_infer::traits::Obligation; use rustc_lint::builtin::REPR_TRANSPARENT_EXTERNAL_PRIVATE_FIELDS; @@ -29,13 +26,12 @@ use rustc_session::lint::builtin::{UNINHABITED_STATIC, UNSUPPORTED_CALLING_CONVE use rustc_span::symbol::sym; use rustc_span::{self, Span}; use rustc_target::spec::abi::Abi; -use rustc_trait_selection::traits::error_reporting::InferCtxtExt as _; +use rustc_trait_selection::traits::error_reporting::TypeErrCtxtExt as _; use rustc_trait_selection::traits::{self, ObligationCtxt}; -use rustc_ty_utils::representability::{self, Representability}; use std::ops::ControlFlow; -pub(super) fn check_abi(tcx: TyCtxt<'_>, hir_id: hir::HirId, span: Span, abi: Abi) { +pub fn check_abi(tcx: TyCtxt<'_>, hir_id: hir::HirId, span: Span, abi: Abi) { match tcx.sess.target.is_abi_supported(abi) { Some(true) => (), Some(false) => { @@ -48,9 +44,13 @@ pub(super) fn check_abi(tcx: TyCtxt<'_>, hir_id: hir::HirId, span: Span, abi: Ab .emit(); } None => { - tcx.struct_span_lint_hir(UNSUPPORTED_CALLING_CONVENTIONS, hir_id, span, |lint| { - lint.build("use of calling convention not supported on this target").emit(); - }); + tcx.struct_span_lint_hir( + UNSUPPORTED_CALLING_CONVENTIONS, + hir_id, + span, + "use of calling convention not supported on this target", + |lint| lint, + ); } } @@ -66,318 +66,10 @@ pub(super) fn check_abi(tcx: TyCtxt<'_>, hir_id: hir::HirId, span: Span, abi: Ab } } -/// Helper used for fns and closures. Does the grungy work of checking a function -/// body and returns the function context used for that purpose, since in the case of a fn item -/// there is still a bit more to do. -/// -/// * ... -/// * inherited: other fields inherited from the enclosing fn (if any) -#[instrument(skip(inherited, body), level = "debug")] -pub(super) fn check_fn<'a, 'tcx>( - inherited: &'a Inherited<'a, 'tcx>, - param_env: ty::ParamEnv<'tcx>, - fn_sig: ty::FnSig<'tcx>, - decl: &'tcx hir::FnDecl<'tcx>, - fn_id: hir::HirId, - body: &'tcx hir::Body<'tcx>, - can_be_generator: Option<hir::Movability>, - return_type_pre_known: bool, -) -> (FnCtxt<'a, 'tcx>, Option<GeneratorTypes<'tcx>>) { - // Create the function context. This is either derived from scratch or, - // in the case of closures, based on the outer context. - let mut fcx = FnCtxt::new(inherited, param_env, body.value.hir_id); - fcx.ps.set(UnsafetyState::function(fn_sig.unsafety, fn_id)); - fcx.return_type_pre_known = return_type_pre_known; - - let tcx = fcx.tcx; - let hir = tcx.hir(); - - let declared_ret_ty = fn_sig.output(); - - let ret_ty = - fcx.register_infer_ok_obligations(fcx.infcx.replace_opaque_types_with_inference_vars( - declared_ret_ty, - body.value.hir_id, - decl.output.span(), - param_env, - )); - // If we replaced declared_ret_ty with infer vars, then we must be inferring - // an opaque type, so set a flag so we can improve diagnostics. - fcx.return_type_has_opaque = ret_ty != declared_ret_ty; - - fcx.ret_coercion = Some(RefCell::new(CoerceMany::new(ret_ty))); - - let span = body.value.span; - - fn_maybe_err(tcx, span, fn_sig.abi); - - if fn_sig.abi == Abi::RustCall { - let expected_args = if let ImplicitSelfKind::None = decl.implicit_self { 1 } else { 2 }; - - let err = || { - let item = match tcx.hir().get(fn_id) { - Node::Item(hir::Item { kind: ItemKind::Fn(header, ..), .. }) => Some(header), - Node::ImplItem(hir::ImplItem { - kind: hir::ImplItemKind::Fn(header, ..), .. - }) => Some(header), - Node::TraitItem(hir::TraitItem { - kind: hir::TraitItemKind::Fn(header, ..), - .. - }) => Some(header), - // Closures are RustCall, but they tuple their arguments, so shouldn't be checked - Node::Expr(hir::Expr { kind: hir::ExprKind::Closure { .. }, .. }) => None, - node => bug!("Item being checked wasn't a function/closure: {:?}", node), - }; - - if let Some(header) = item { - tcx.sess.span_err(header.span, "functions with the \"rust-call\" ABI must take a single non-self argument that is a tuple"); - } - }; - - if fn_sig.inputs().len() != expected_args { - err() - } else { - // FIXME(CraftSpider) Add a check on parameter expansion, so we don't just make the ICE happen later on - // This will probably require wide-scale changes to support a TupleKind obligation - // We can't resolve this without knowing the type of the param - if !matches!(fn_sig.inputs()[expected_args - 1].kind(), ty::Tuple(_) | ty::Param(_)) { - err() - } - } - } - - if body.generator_kind.is_some() && can_be_generator.is_some() { - let yield_ty = fcx - .next_ty_var(TypeVariableOrigin { kind: TypeVariableOriginKind::TypeInference, span }); - fcx.require_type_is_sized(yield_ty, span, traits::SizedYieldType); - - // Resume type defaults to `()` if the generator has no argument. - let resume_ty = fn_sig.inputs().get(0).copied().unwrap_or_else(|| tcx.mk_unit()); - - fcx.resume_yield_tys = Some((resume_ty, yield_ty)); - } - - GatherLocalsVisitor::new(&fcx).visit_body(body); - - // C-variadic fns also have a `VaList` input that's not listed in `fn_sig` - // (as it's created inside the body itself, not passed in from outside). - let maybe_va_list = if fn_sig.c_variadic { - let span = body.params.last().unwrap().span; - let va_list_did = tcx.require_lang_item(LangItem::VaList, Some(span)); - let region = fcx.next_region_var(RegionVariableOrigin::MiscVariable(span)); - - Some(tcx.bound_type_of(va_list_did).subst(tcx, &[region.into()])) - } else { - None - }; - - // Add formal parameters. - let inputs_hir = hir.fn_decl_by_hir_id(fn_id).map(|decl| &decl.inputs); - let inputs_fn = fn_sig.inputs().iter().copied(); - for (idx, (param_ty, param)) in inputs_fn.chain(maybe_va_list).zip(body.params).enumerate() { - // Check the pattern. - let ty_span = try { inputs_hir?.get(idx)?.span }; - fcx.check_pat_top(¶m.pat, param_ty, ty_span, false); - - // Check that argument is Sized. - // The check for a non-trivial pattern is a hack to avoid duplicate warnings - // for simple cases like `fn foo(x: Trait)`, - // where we would error once on the parameter as a whole, and once on the binding `x`. - if param.pat.simple_ident().is_none() && !tcx.features().unsized_fn_params { - fcx.require_type_is_sized(param_ty, param.pat.span, traits::SizedArgumentType(ty_span)); - } - - fcx.write_ty(param.hir_id, param_ty); - } - - inherited.typeck_results.borrow_mut().liberated_fn_sigs_mut().insert(fn_id, fn_sig); - - fcx.in_tail_expr = true; - if let ty::Dynamic(..) = declared_ret_ty.kind() { - // FIXME: We need to verify that the return type is `Sized` after the return expression has - // been evaluated so that we have types available for all the nodes being returned, but that - // requires the coerced evaluated type to be stored. Moving `check_return_expr` before this - // causes unsized errors caused by the `declared_ret_ty` to point at the return expression, - // while keeping the current ordering we will ignore the tail expression's type because we - // don't know it yet. We can't do `check_expr_kind` while keeping `check_return_expr` - // because we will trigger "unreachable expression" lints unconditionally. - // Because of all of this, we perform a crude check to know whether the simplest `!Sized` - // case that a newcomer might make, returning a bare trait, and in that case we populate - // the tail expression's type so that the suggestion will be correct, but ignore all other - // possible cases. - fcx.check_expr(&body.value); - fcx.require_type_is_sized(declared_ret_ty, decl.output.span(), traits::SizedReturnType); - } else { - fcx.require_type_is_sized(declared_ret_ty, decl.output.span(), traits::SizedReturnType); - fcx.check_return_expr(&body.value, false); - } - fcx.in_tail_expr = false; - - // We insert the deferred_generator_interiors entry after visiting the body. - // This ensures that all nested generators appear before the entry of this generator. - // resolve_generator_interiors relies on this property. - let gen_ty = if let (Some(_), Some(gen_kind)) = (can_be_generator, body.generator_kind) { - let interior = fcx - .next_ty_var(TypeVariableOrigin { kind: TypeVariableOriginKind::MiscVariable, span }); - fcx.deferred_generator_interiors.borrow_mut().push((body.id(), interior, gen_kind)); - - let (resume_ty, yield_ty) = fcx.resume_yield_tys.unwrap(); - Some(GeneratorTypes { - resume_ty, - yield_ty, - interior, - movability: can_be_generator.unwrap(), - }) - } else { - None - }; - - // Finalize the return check by taking the LUB of the return types - // we saw and assigning it to the expected return type. This isn't - // really expected to fail, since the coercions would have failed - // earlier when trying to find a LUB. - let coercion = fcx.ret_coercion.take().unwrap().into_inner(); - let mut actual_return_ty = coercion.complete(&fcx); - debug!("actual_return_ty = {:?}", actual_return_ty); - if let ty::Dynamic(..) = declared_ret_ty.kind() { - // We have special-cased the case where the function is declared - // `-> dyn Foo` and we don't actually relate it to the - // `fcx.ret_coercion`, so just substitute a type variable. - actual_return_ty = - fcx.next_ty_var(TypeVariableOrigin { kind: TypeVariableOriginKind::DynReturnFn, span }); - debug!("actual_return_ty replaced with {:?}", actual_return_ty); - } - - // HACK(oli-obk, compiler-errors): We should be comparing this against - // `declared_ret_ty`, but then anything uninferred would be inferred to - // the opaque type itself. That again would cause writeback to assume - // we have a recursive call site and do the sadly stabilized fallback to `()`. - fcx.demand_suptype(span, ret_ty, actual_return_ty); - - // Check that a function marked as `#[panic_handler]` has signature `fn(&PanicInfo) -> !` - if let Some(panic_impl_did) = tcx.lang_items().panic_impl() - && panic_impl_did == hir.local_def_id(fn_id).to_def_id() - { - check_panic_info_fn(tcx, panic_impl_did.expect_local(), fn_sig, decl, declared_ret_ty); - } - - // Check that a function marked as `#[alloc_error_handler]` has signature `fn(Layout) -> !` - if let Some(alloc_error_handler_did) = tcx.lang_items().oom() - && alloc_error_handler_did == hir.local_def_id(fn_id).to_def_id() - { - check_alloc_error_fn(tcx, alloc_error_handler_did.expect_local(), fn_sig, decl, declared_ret_ty); - } - - (fcx, gen_ty) -} - -fn check_panic_info_fn( - tcx: TyCtxt<'_>, - fn_id: LocalDefId, - fn_sig: ty::FnSig<'_>, - decl: &hir::FnDecl<'_>, - declared_ret_ty: Ty<'_>, -) { - let Some(panic_info_did) = tcx.lang_items().panic_info() else { - tcx.sess.err("language item required, but not found: `panic_info`"); - return; - }; - - if *declared_ret_ty.kind() != ty::Never { - tcx.sess.span_err(decl.output.span(), "return type should be `!`"); - } - - let inputs = fn_sig.inputs(); - if inputs.len() != 1 { - tcx.sess.span_err(tcx.def_span(fn_id), "function should have one argument"); - return; - } - - let arg_is_panic_info = match *inputs[0].kind() { - ty::Ref(region, ty, mutbl) => match *ty.kind() { - ty::Adt(ref adt, _) => { - adt.did() == panic_info_did && mutbl == hir::Mutability::Not && !region.is_static() - } - _ => false, - }, - _ => false, - }; - - if !arg_is_panic_info { - tcx.sess.span_err(decl.inputs[0].span, "argument should be `&PanicInfo`"); - } - - let DefKind::Fn = tcx.def_kind(fn_id) else { - let span = tcx.def_span(fn_id); - tcx.sess.span_err(span, "should be a function"); - return; - }; - - let generic_counts = tcx.generics_of(fn_id).own_counts(); - if generic_counts.types != 0 { - let span = tcx.def_span(fn_id); - tcx.sess.span_err(span, "should have no type parameters"); - } - if generic_counts.consts != 0 { - let span = tcx.def_span(fn_id); - tcx.sess.span_err(span, "should have no const parameters"); - } -} - -fn check_alloc_error_fn( - tcx: TyCtxt<'_>, - fn_id: LocalDefId, - fn_sig: ty::FnSig<'_>, - decl: &hir::FnDecl<'_>, - declared_ret_ty: Ty<'_>, -) { - let Some(alloc_layout_did) = tcx.lang_items().alloc_layout() else { - tcx.sess.err("language item required, but not found: `alloc_layout`"); - return; - }; - - if *declared_ret_ty.kind() != ty::Never { - tcx.sess.span_err(decl.output.span(), "return type should be `!`"); - } - - let inputs = fn_sig.inputs(); - if inputs.len() != 1 { - tcx.sess.span_err(tcx.def_span(fn_id), "function should have one argument"); - return; - } - - let arg_is_alloc_layout = match inputs[0].kind() { - ty::Adt(ref adt, _) => adt.did() == alloc_layout_did, - _ => false, - }; - - if !arg_is_alloc_layout { - tcx.sess.span_err(decl.inputs[0].span, "argument should be `Layout`"); - } - - let DefKind::Fn = tcx.def_kind(fn_id) else { - let span = tcx.def_span(fn_id); - tcx.sess.span_err(span, "`#[alloc_error_handler]` should be a function"); - return; - }; - - let generic_counts = tcx.generics_of(fn_id).own_counts(); - if generic_counts.types != 0 { - let span = tcx.def_span(fn_id); - tcx.sess.span_err(span, "`#[alloc_error_handler]` function should have no type parameters"); - } - if generic_counts.consts != 0 { - let span = tcx.def_span(fn_id); - tcx.sess - .span_err(span, "`#[alloc_error_handler]` function should have no const parameters"); - } -} - fn check_struct(tcx: TyCtxt<'_>, def_id: LocalDefId) { let def = tcx.adt_def(def_id); let span = tcx.def_span(def_id); def.destructor(tcx); // force the destructor to be evaluated - check_representable(tcx, span, def_id); if def.repr().simd() { check_simd(tcx, span, def_id); @@ -391,7 +83,6 @@ fn check_union(tcx: TyCtxt<'_>, def_id: LocalDefId) { let def = tcx.adt_def(def_id); let span = tcx.def_span(def_id); def.destructor(tcx); // force the destructor to be evaluated - check_representable(tcx, span, def_id); check_transparent(tcx, span, def); check_union_fields(tcx, span, def_id); check_packed(tcx, span, def); @@ -423,7 +114,7 @@ fn check_union_fields(tcx: TyCtxt<'_>, span: Span, item_def_id: LocalDefId) -> b _ => { // Fallback case: allow `ManuallyDrop` and things that are `Copy`. ty.ty_adt_def().is_some_and(|adt_def| adt_def.is_manually_drop()) - || ty.is_copy_modulo_regions(tcx.at(span), param_env) + || ty.is_copy_modulo_regions(tcx, param_env) } } } @@ -510,10 +201,10 @@ fn check_static_inhabited<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) { UNINHABITED_STATIC, tcx.hir().local_def_id_to_hir_id(def_id), span, + "static of uninhabited type", |lint| { - lint.build("static of uninhabited type") + lint .note("uninhabited statics cannot be initialized, and any access would be an immediate error") - .emit(); }, ); } @@ -521,23 +212,33 @@ fn check_static_inhabited<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) { /// Checks that an opaque type does not contain cycles and does not use `Self` or `T::Foo` /// projections that would result in "inheriting lifetimes". -pub(super) fn check_opaque<'tcx>( - tcx: TyCtxt<'tcx>, - def_id: LocalDefId, - substs: SubstsRef<'tcx>, - origin: &hir::OpaqueTyOrigin, -) { - let span = tcx.def_span(def_id); - check_opaque_for_inheriting_lifetimes(tcx, def_id, span); - if tcx.type_of(def_id).references_error() { +fn check_opaque<'tcx>(tcx: TyCtxt<'tcx>, id: hir::ItemId) { + let item = tcx.hir().item(id); + let hir::ItemKind::OpaqueTy(hir::OpaqueTy { origin, .. }) = item.kind else { + tcx.sess.delay_span_bug(tcx.hir().span(id.hir_id()), "expected opaque item"); + return; + }; + + // HACK(jynelson): trying to infer the type of `impl trait` breaks documenting + // `async-std` (and `pub async fn` in general). + // Since rustdoc doesn't care about the concrete type behind `impl Trait`, just don't look at it! + // See https://github.com/rust-lang/rust/issues/75100 + if tcx.sess.opts.actually_rustdoc { + return; + } + + let substs = InternalSubsts::identity_for_item(tcx, item.owner_id.to_def_id()); + let span = tcx.def_span(item.owner_id.def_id); + + check_opaque_for_inheriting_lifetimes(tcx, item.owner_id.def_id, span); + if tcx.type_of(item.owner_id.def_id).references_error() { return; } - if check_opaque_for_cycles(tcx, def_id, substs, span, origin).is_err() { + if check_opaque_for_cycles(tcx, item.owner_id.def_id, substs, span, &origin).is_err() { return; } - check_opaque_meets_bounds(tcx, def_id, substs, span, origin); + check_opaque_meets_bounds(tcx, item.owner_id.def_id, substs, span, &origin); } - /// Checks that an opaque type does not use `Self` or `T::Foo` projections that would result /// in "inheriting lifetimes". #[instrument(level = "debug", skip(tcx, span))] @@ -609,9 +310,12 @@ pub(super) fn check_opaque_for_inheriting_lifetimes<'tcx>( fn visit_ty(&mut self, arg: &'tcx hir::Ty<'tcx>) { match arg.kind { hir::TyKind::Path(hir::QPath::Resolved(None, path)) => match &path.segments { - [PathSegment { res: Res::SelfTy { trait_: _, alias_to: impl_ref }, .. }] => { - let impl_ty_name = - impl_ref.map(|(def_id, _)| self.tcx.def_path_str(def_id)); + [PathSegment { res: Res::SelfTyParam { .. }, .. }] => { + let impl_ty_name = None; + self.selftys.push((path.span, impl_ty_name)); + } + [PathSegment { res: Res::SelfTyAlias { alias_to: def_id, .. }, .. }] => { + let impl_ty_name = Some(self.tcx.def_path_str(*def_id)); self.selftys.push((path.span, impl_ty_name)); } _ => {} @@ -701,10 +405,12 @@ pub(super) fn check_opaque_for_cycles<'tcx>( /// check those cases in the `param_env` of that function, which may have /// bounds not on this opaque type: /// -/// type X<T> = impl Clone +/// ```ignore (illustrative) +/// type X<T> = impl Clone; /// fn f<T: Clone>(t: T) -> X<T> { /// t /// } +/// ``` /// /// Without this check the above code is incorrectly accepted: we would ICE if /// some tried, for example, to clone an `Option<X<&mut ()>>`. @@ -716,8 +422,6 @@ fn check_opaque_meets_bounds<'tcx>( span: Span, origin: &hir::OpaqueTyOrigin, ) { - let hidden_type = tcx.bound_type_of(def_id.to_def_id()).subst(tcx, substs); - let hir_id = tcx.hir().local_def_id_to_hir_id(def_id); let defining_use_anchor = match *origin { hir::OpaqueTyOrigin::FnReturn(did) | hir::OpaqueTyOrigin::AsyncFn(did) => did, @@ -725,76 +429,88 @@ fn check_opaque_meets_bounds<'tcx>( }; let param_env = tcx.param_env(defining_use_anchor); - tcx.infer_ctxt().with_opaque_type_inference(DefiningAnchor::Bind(defining_use_anchor)).enter( - move |infcx| { - let ocx = ObligationCtxt::new(&infcx); - let opaque_ty = tcx.mk_opaque(def_id.to_def_id(), substs); + let infcx = tcx + .infer_ctxt() + .with_opaque_type_inference(DefiningAnchor::Bind(defining_use_anchor)) + .build(); + let ocx = ObligationCtxt::new(&infcx); + let opaque_ty = tcx.mk_opaque(def_id.to_def_id(), substs); + + // `ReErased` regions appear in the "parent_substs" of closures/generators. + // We're ignoring them here and replacing them with fresh region variables. + // See tests in ui/type-alias-impl-trait/closure_{parent_substs,wf_outlives}.rs. + // + // FIXME: Consider wrapping the hidden type in an existential `Binder` and instantiating it + // here rather than using ReErased. + let hidden_ty = tcx.bound_type_of(def_id.to_def_id()).subst(tcx, substs); + let hidden_ty = tcx.fold_regions(hidden_ty, |re, _dbi| match re.kind() { + ty::ReErased => infcx.next_region_var(RegionVariableOrigin::MiscVariable(span)), + _ => re, + }); - let misc_cause = traits::ObligationCause::misc(span, hir_id); + let misc_cause = traits::ObligationCause::misc(span, hir_id); - match infcx.at(&misc_cause, param_env).eq(opaque_ty, hidden_type) { - Ok(infer_ok) => ocx.register_infer_ok_obligations(infer_ok), - Err(ty_err) => { - tcx.sess.delay_span_bug( - span, - &format!("could not unify `{hidden_type}` with revealed type:\n{ty_err}"), - ); - } - } + match infcx.at(&misc_cause, param_env).eq(opaque_ty, hidden_ty) { + Ok(infer_ok) => ocx.register_infer_ok_obligations(infer_ok), + Err(ty_err) => { + tcx.sess.delay_span_bug( + span, + &format!("could not unify `{hidden_ty}` with revealed type:\n{ty_err}"), + ); + } + } - // Additionally require the hidden type to be well-formed with only the generics of the opaque type. - // Defining use functions may have more bounds than the opaque type, which is ok, as long as the - // hidden type is well formed even without those bounds. - let predicate = ty::Binder::dummy(ty::PredicateKind::WellFormed(hidden_type.into())) - .to_predicate(tcx); - ocx.register_obligation(Obligation::new(misc_cause, param_env, predicate)); - - // Check that all obligations are satisfied by the implementation's - // version. - let errors = ocx.select_all_or_error(); - if !errors.is_empty() { - infcx.report_fulfillment_errors(&errors, None, false); - } - match origin { - // Checked when type checking the function containing them. - hir::OpaqueTyOrigin::FnReturn(..) | hir::OpaqueTyOrigin::AsyncFn(..) => {} - // Can have different predicates to their defining use - hir::OpaqueTyOrigin::TyAlias => { - let outlives_environment = OutlivesEnvironment::new(param_env); - infcx.check_region_obligations_and_report_errors( - defining_use_anchor, - &outlives_environment, - ); - } - } - // Clean up after ourselves - let _ = infcx.inner.borrow_mut().opaque_type_storage.take_opaque_types(); - }, - ); + // Additionally require the hidden type to be well-formed with only the generics of the opaque type. + // Defining use functions may have more bounds than the opaque type, which is ok, as long as the + // hidden type is well formed even without those bounds. + let predicate = + ty::Binder::dummy(ty::PredicateKind::WellFormed(hidden_ty.into())).to_predicate(tcx); + ocx.register_obligation(Obligation::new(misc_cause, param_env, predicate)); + + // Check that all obligations are satisfied by the implementation's + // version. + let errors = ocx.select_all_or_error(); + if !errors.is_empty() { + infcx.err_ctxt().report_fulfillment_errors(&errors, None, false); + } + match origin { + // Checked when type checking the function containing them. + hir::OpaqueTyOrigin::FnReturn(..) | hir::OpaqueTyOrigin::AsyncFn(..) => {} + // Can have different predicates to their defining use + hir::OpaqueTyOrigin::TyAlias => { + let outlives_environment = OutlivesEnvironment::new(param_env); + infcx.check_region_obligations_and_report_errors( + defining_use_anchor, + &outlives_environment, + ); + } + } + // Clean up after ourselves + let _ = infcx.inner.borrow_mut().opaque_type_storage.take_opaque_types(); } fn check_item_type<'tcx>(tcx: TyCtxt<'tcx>, id: hir::ItemId) { debug!( "check_item_type(it.def_id={:?}, it.name={})", - id.def_id, - tcx.def_path_str(id.def_id.to_def_id()) + id.owner_id, + tcx.def_path_str(id.owner_id.to_def_id()) ); let _indenter = indenter(); - match tcx.def_kind(id.def_id) { + match tcx.def_kind(id.owner_id) { DefKind::Static(..) => { - tcx.ensure().typeck(id.def_id); - maybe_check_static_with_link_section(tcx, id.def_id); - check_static_inhabited(tcx, id.def_id); + tcx.ensure().typeck(id.owner_id.def_id); + maybe_check_static_with_link_section(tcx, id.owner_id.def_id); + check_static_inhabited(tcx, id.owner_id.def_id); } DefKind::Const => { - tcx.ensure().typeck(id.def_id); + tcx.ensure().typeck(id.owner_id.def_id); } DefKind::Enum => { let item = tcx.hir().item(id); let hir::ItemKind::Enum(ref enum_definition, _) = item.kind else { return; }; - check_enum(tcx, &enum_definition.variants, item.def_id); + check_enum(tcx, &enum_definition.variants, item.owner_id.def_id); } DefKind::Fn => {} // entirely within check_item_body DefKind::Impl => { @@ -802,12 +518,12 @@ fn check_item_type<'tcx>(tcx: TyCtxt<'tcx>, id: hir::ItemId) { let hir::ItemKind::Impl(ref impl_) = it.kind else { return; }; - debug!("ItemKind::Impl {} with id {:?}", it.ident, it.def_id); - if let Some(impl_trait_ref) = tcx.impl_trait_ref(it.def_id) { + debug!("ItemKind::Impl {} with id {:?}", it.ident, it.owner_id); + if let Some(impl_trait_ref) = tcx.impl_trait_ref(it.owner_id) { check_impl_items_against_trait( tcx, it.span, - it.def_id, + it.owner_id.def_id, impl_trait_ref, &impl_.items, ); @@ -829,15 +545,15 @@ fn check_item_type<'tcx>(tcx: TyCtxt<'tcx>, id: hir::ItemId) { fn_maybe_err(tcx, item.ident.span, abi); } hir::TraitItemKind::Type(.., Some(default)) => { - let assoc_item = tcx.associated_item(item.def_id); + let assoc_item = tcx.associated_item(item.owner_id); let trait_substs = - InternalSubsts::identity_for_item(tcx, it.def_id.to_def_id()); + InternalSubsts::identity_for_item(tcx, it.owner_id.to_def_id()); let _: Result<_, rustc_errors::ErrorGuaranteed> = check_type_bounds( tcx, assoc_item, assoc_item, default.span, - ty::TraitRef { def_id: it.def_id.to_def_id(), substs: trait_substs }, + ty::TraitRef { def_id: it.owner_id.to_def_id(), substs: trait_substs }, ); } _ => {} @@ -845,28 +561,28 @@ fn check_item_type<'tcx>(tcx: TyCtxt<'tcx>, id: hir::ItemId) { } } DefKind::Struct => { - check_struct(tcx, id.def_id); + check_struct(tcx, id.owner_id.def_id); } DefKind::Union => { - check_union(tcx, id.def_id); + check_union(tcx, id.owner_id.def_id); } DefKind::OpaqueTy => { - let item = tcx.hir().item(id); - let hir::ItemKind::OpaqueTy(hir::OpaqueTy { origin, .. }) = item.kind else { - return; - }; - // HACK(jynelson): trying to infer the type of `impl trait` breaks documenting - // `async-std` (and `pub async fn` in general). - // Since rustdoc doesn't care about the concrete type behind `impl Trait`, just don't look at it! - // See https://github.com/rust-lang/rust/issues/75100 - if !tcx.sess.opts.actually_rustdoc { - let substs = InternalSubsts::identity_for_item(tcx, item.def_id.to_def_id()); - check_opaque(tcx, item.def_id, substs, &origin); + check_opaque(tcx, id); + } + DefKind::ImplTraitPlaceholder => { + let parent = tcx.impl_trait_in_trait_parent(id.owner_id.to_def_id()); + // Only check the validity of this opaque type if the function has a default body + if let hir::Node::TraitItem(hir::TraitItem { + kind: hir::TraitItemKind::Fn(_, hir::TraitFn::Provided(_)), + .. + }) = tcx.hir().get_by_def_id(parent.expect_local()) + { + check_opaque(tcx, id); } } DefKind::TyAlias => { - let pty_ty = tcx.type_of(id.def_id); - let generics = tcx.generics_of(id.def_id); + let pty_ty = tcx.type_of(id.owner_id); + let generics = tcx.generics_of(id.owner_id); check_type_params_are_used(tcx, &generics, pty_ty); } DefKind::ForeignMod => { @@ -888,7 +604,7 @@ fn check_item_type<'tcx>(tcx: TyCtxt<'tcx>, id: hir::ItemId) { } } else { for item in items { - let def_id = item.id.def_id; + let def_id = item.id.owner_id.def_id; let generics = tcx.generics_of(def_id); let own_counts = generics.own_counts(); if generics.params.len() - own_counts.lifetimes != 0 { @@ -943,7 +659,7 @@ fn check_item_type<'tcx>(tcx: TyCtxt<'tcx>, id: hir::ItemId) { pub(super) fn check_on_unimplemented(tcx: TyCtxt<'_>, item: &hir::Item<'_>) { // an error would be reported if this fails. - let _ = traits::OnUnimplementedDirective::of_item(tcx, item.def_id.to_def_id()); + let _ = traits::OnUnimplementedDirective::of_item(tcx, item.owner_id.to_def_id()); } pub(super) fn check_specialization_validity<'tcx>( @@ -1030,7 +746,7 @@ fn check_impl_items_against_trait<'tcx>( let trait_def = tcx.trait_def(impl_trait_ref.def_id); for impl_item in impl_item_refs { - let ty_impl_item = tcx.associated_item(impl_item.id.def_id); + let ty_impl_item = tcx.associated_item(impl_item.id.owner_id); let ty_trait_item = if let Some(trait_item_id) = ty_impl_item.trait_item_def_id { tcx.associated_item(trait_item_id) } else { @@ -1041,14 +757,10 @@ fn check_impl_items_against_trait<'tcx>( let impl_item_full = tcx.hir().impl_item(impl_item.id); match impl_item_full.kind { hir::ImplItemKind::Const(..) => { - // Find associated const definition. - compare_const_impl( - tcx, - &ty_impl_item, - impl_item.span, - &ty_trait_item, - impl_trait_ref, - ); + let _ = tcx.compare_assoc_const_impl_item_with_trait_item(( + impl_item.id.owner_id.def_id, + ty_impl_item.trait_item_def_id.unwrap(), + )); } hir::ImplItemKind::Fn(..) => { let opt_trait_span = tcx.hir().span_if_local(ty_trait_item.def_id); @@ -1060,7 +772,7 @@ fn check_impl_items_against_trait<'tcx>( opt_trait_span, ); } - hir::ImplItemKind::TyAlias(impl_ty) => { + hir::ImplItemKind::Type(impl_ty) => { let opt_trait_span = tcx.hir().span_if_local(ty_trait_item.def_id); compare_ty_impl( tcx, @@ -1148,27 +860,6 @@ fn check_impl_items_against_trait<'tcx>( } } -/// Checks whether a type can be represented in memory. In particular, it -/// identifies types that contain themselves without indirection through a -/// pointer, which would mean their size is unbounded. -pub(super) fn check_representable(tcx: TyCtxt<'_>, sp: Span, item_def_id: LocalDefId) -> bool { - let rty = tcx.type_of(item_def_id); - - // Check that it is possible to represent this type. This call identifies - // (1) types that contain themselves and (2) types that contain a different - // recursive type. It is only necessary to throw an error on those that - // contain themselves. For case 2, there must be an inner type that will be - // caught by case 1. - match representability::ty_is_representable(tcx, rty, sp, None) { - Representability::SelfRecursive(spans) => { - recursive_type_with_infinite_size_error(tcx, item_def_id.to_def_id(), spans); - return false; - } - Representability::Representable | Representability::ContainsRecursive => (), - } - true -} - pub fn check_simd(tcx: TyCtxt<'_>, sp: Span, def_id: LocalDefId) { let t = tcx.type_of(def_id); if let ty::Adt(def, substs) = t.kind() @@ -1434,6 +1125,7 @@ pub(super) fn check_transparent<'tcx>(tcx: TyCtxt<'tcx>, sp: Span, adt: ty::AdtD REPR_TRANSPARENT_EXTERNAL_PRIVATE_FIELDS, tcx.hir().local_def_id_to_hir_id(adt.did().expect_local()), span, + "zero-sized fields in `repr(transparent)` cannot contain external non-exhaustive types", |lint| { let note = if non_exhaustive { "is marked with `#[non_exhaustive]`" @@ -1441,10 +1133,9 @@ pub(super) fn check_transparent<'tcx>(tcx: TyCtxt<'tcx>, sp: Span, adt: ty::AdtD "contains private fields" }; let field_ty = tcx.def_path_str_with_substs(def_id, substs); - lint.build("zero-sized fields in repr(transparent) cannot contain external non-exhaustive types") + lint .note(format!("this {descr} contains `{field_ty}`, which {note}, \ and makes it not a breaking change to become non-zero-sized in the future.")) - .emit(); }, ) } @@ -1489,7 +1180,7 @@ fn check_enum<'tcx>(tcx: TyCtxt<'tcx>, vs: &'tcx [hir::Variant<'tcx>], def_id: L } } - if tcx.adt_def(def_id).repr().int.is_none() && tcx.features().arbitrary_enum_discriminant { + if tcx.adt_def(def_id).repr().int.is_none() { let is_unit = |var: &hir::Variant<'_>| matches!(var.data, hir::VariantData::Unit(..)); let has_disr = |var: &hir::Variant<'_>| var.disr_expr.is_some(); @@ -1506,7 +1197,6 @@ fn check_enum<'tcx>(tcx: TyCtxt<'tcx>, vs: &'tcx [hir::Variant<'tcx>], def_id: L detect_discriminant_duplicate(tcx, def.discriminants(tcx).collect(), vs, sp); - check_representable(tcx, sp, def_id); check_transparent(tcx, sp, def); } |