diff options
Diffstat (limited to 'compiler/rustc_hir_analysis/src/check/check.rs')
| -rw-r--r-- | compiler/rustc_hir_analysis/src/check/check.rs | 215 |
1 files changed, 120 insertions, 95 deletions
diff --git a/compiler/rustc_hir_analysis/src/check/check.rs b/compiler/rustc_hir_analysis/src/check/check.rs index 9ed56d7bde5..f2331f3fd8e 100644 --- a/compiler/rustc_hir_analysis/src/check/check.rs +++ b/compiler/rustc_hir_analysis/src/check/check.rs @@ -2,11 +2,13 @@ use std::cell::LazyCell; use std::ops::ControlFlow; use rustc_abi::FieldIdx; +use rustc_attr_parsing::AttributeKind; +use rustc_attr_parsing::ReprAttr::ReprPacked; use rustc_data_structures::unord::{UnordMap, UnordSet}; use rustc_errors::MultiSpan; use rustc_errors::codes::*; use rustc_hir::def::{CtorKind, DefKind}; -use rustc_hir::{Node, intravisit}; +use rustc_hir::{LangItem, Node, intravisit}; use rustc_infer::infer::{RegionVariableOrigin, TyCtxtInferExt}; use rustc_infer::traits::{Obligation, ObligationCauseCode}; use rustc_lint_defs::builtin::{ @@ -15,7 +17,6 @@ use rustc_lint_defs::builtin::{ use rustc_middle::hir::nested_filter; use rustc_middle::middle::resolve_bound_vars::ResolvedArg; use rustc_middle::middle::stability::EvalResult; -use rustc_middle::span_bug; use rustc_middle::ty::error::TypeErrorToStringExt; use rustc_middle::ty::fold::{BottomUpFolder, fold_regions}; use rustc_middle::ty::layout::{LayoutError, MAX_SIMD_LANES}; @@ -27,6 +28,7 @@ use rustc_session::lint::builtin::UNINHABITED_STATIC; use rustc_trait_selection::error_reporting::InferCtxtErrorExt; use rustc_trait_selection::error_reporting::traits::on_unimplemented::OnUnimplementedDirective; use rustc_trait_selection::traits; +use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt; use rustc_type_ir::fold::TypeFoldable; use tracing::{debug, instrument}; use ty::TypingMode; @@ -34,7 +36,6 @@ use {rustc_attr_parsing as attr, rustc_hir as hir}; use super::compare_impl_item::check_type_bounds; use super::*; -use crate::check::intrinsicck::InlineAsmCtxt; pub fn check_abi(tcx: TyCtxt<'_>, span: Span, abi: ExternAbi) { if !tcx.sess.target.is_abi_supported(abi) { @@ -87,89 +88,76 @@ fn allowed_union_or_unsafe_field<'tcx>( typing_env: ty::TypingEnv<'tcx>, span: Span, ) -> bool { - // We don't just accept all !needs_drop fields, due to semver concerns. - let allowed = match ty.kind() { - ty::Ref(..) => true, // references never drop (even mutable refs, which are non-Copy and hence fail the later check) - ty::Tuple(tys) => { - // allow tuples of allowed types - tys.iter().all(|ty| allowed_union_or_unsafe_field(tcx, ty, typing_env, span)) - } - ty::Array(elem, _len) => { - // Like `Copy`, we do *not* special-case length 0. - allowed_union_or_unsafe_field(tcx, *elem, typing_env, span) - } - _ => { - // Fallback case: allow `ManuallyDrop` and things that are `Copy`, - // also no need to report an error if the type is unresolved. - ty.ty_adt_def().is_some_and(|adt_def| adt_def.is_manually_drop()) - || tcx.type_is_copy_modulo_regions(typing_env, ty) - || ty.references_error() - } - }; - if allowed && ty.needs_drop(tcx, typing_env) { - // This should never happen. But we can get here e.g. in case of name resolution errors. - tcx.dcx() - .span_delayed_bug(span, "we should never accept maybe-dropping union or unsafe fields"); + // HACK (not that bad of a hack don't worry): Some codegen tests don't even define proper + // impls for `Copy`. Let's short-circuit here for this validity check, since a lot of them + // use unions. We should eventually fix all the tests to define that lang item or use + // minicore stubs. + if ty.is_trivially_pure_clone_copy() { + return true; } - allowed + // If `BikeshedGuaranteedNoDrop` is not defined in a `#[no_core]` test, fall back to `Copy`. + // This is an underapproximation of `BikeshedGuaranteedNoDrop`, + let def_id = tcx + .lang_items() + .get(LangItem::BikeshedGuaranteedNoDrop) + .unwrap_or_else(|| tcx.require_lang_item(LangItem::Copy, Some(span))); + let Ok(ty) = tcx.try_normalize_erasing_regions(typing_env, ty) else { + tcx.dcx().span_delayed_bug(span, "could not normalize field type"); + return true; + }; + let (infcx, param_env) = tcx.infer_ctxt().build_with_typing_env(typing_env); + infcx.predicate_must_hold_modulo_regions(&Obligation::new( + tcx, + ObligationCause::dummy_with_span(span), + param_env, + ty::TraitRef::new(tcx, def_id, [ty]), + )) } /// Check that the fields of the `union` do not need dropping. fn check_union_fields(tcx: TyCtxt<'_>, span: Span, item_def_id: LocalDefId) -> bool { - let item_type = tcx.type_of(item_def_id).instantiate_identity(); - if let ty::Adt(def, args) = item_type.kind() { - assert!(def.is_union()); - - let typing_env = ty::TypingEnv::non_body_analysis(tcx, item_def_id); - for field in &def.non_enum_variant().fields { - let Ok(field_ty) = tcx.try_normalize_erasing_regions(typing_env, field.ty(tcx, args)) - else { - tcx.dcx().span_delayed_bug(span, "could not normalize field type"); - continue; - }; + let def = tcx.adt_def(item_def_id); + assert!(def.is_union()); - if !allowed_union_or_unsafe_field(tcx, field_ty, typing_env, span) { - let (field_span, ty_span) = match tcx.hir().get_if_local(field.did) { - // We are currently checking the type this field came from, so it must be local. - Some(Node::Field(field)) => (field.span, field.ty.span), - _ => unreachable!("mir field has to correspond to hir field"), - }; - tcx.dcx().emit_err(errors::InvalidUnionField { - field_span, - sugg: errors::InvalidUnionFieldSuggestion { - lo: ty_span.shrink_to_lo(), - hi: ty_span.shrink_to_hi(), - }, - note: (), - }); - return false; - } + let typing_env = ty::TypingEnv::non_body_analysis(tcx, item_def_id); + let args = ty::GenericArgs::identity_for_item(tcx, item_def_id); + + for field in &def.non_enum_variant().fields { + if !allowed_union_or_unsafe_field(tcx, field.ty(tcx, args), typing_env, span) { + let (field_span, ty_span) = match tcx.hir_get_if_local(field.did) { + // We are currently checking the type this field came from, so it must be local. + Some(Node::Field(field)) => (field.span, field.ty.span), + _ => unreachable!("mir field has to correspond to hir field"), + }; + tcx.dcx().emit_err(errors::InvalidUnionField { + field_span, + sugg: errors::InvalidUnionFieldSuggestion { + lo: ty_span.shrink_to_lo(), + hi: ty_span.shrink_to_hi(), + }, + note: (), + }); + return false; } - } else { - span_bug!(span, "unions must be ty::Adt, but got {:?}", item_type.kind()); } + true } /// Check that the unsafe fields do not need dropping. fn check_unsafe_fields(tcx: TyCtxt<'_>, item_def_id: LocalDefId) { let span = tcx.def_span(item_def_id); - let item_type = tcx.type_of(item_def_id).instantiate_identity(); - let ty::Adt(def, args) = item_type.kind() else { - span_bug!(span, "structs/enums must be ty::Adt, but got {:?}", item_type.kind()); - }; + let def = tcx.adt_def(item_def_id); + let typing_env = ty::TypingEnv::non_body_analysis(tcx, item_def_id); + let args = ty::GenericArgs::identity_for_item(tcx, item_def_id); + for field in def.all_fields() { if !field.safety.is_unsafe() { continue; } - let Ok(field_ty) = tcx.try_normalize_erasing_regions(typing_env, field.ty(tcx, args)) - else { - tcx.dcx().span_delayed_bug(span, "could not normalize field type"); - continue; - }; - if !allowed_union_or_unsafe_field(tcx, field_ty, typing_env, span) { + if !allowed_union_or_unsafe_field(tcx, field.ty(tcx, args), typing_env, span) { let hir::Node::Field(field) = tcx.hir_node_by_def_id(field.did.expect_local()) else { unreachable!("field has to correspond to hir field") }; @@ -447,8 +435,8 @@ fn best_definition_site_of_opaque<'tcx>( impl<'tcx> intravisit::Visitor<'tcx> for TaitConstraintLocator<'tcx> { type NestedFilter = nested_filter::All; type Result = ControlFlow<(Span, LocalDefId)>; - fn nested_visit_map(&mut self) -> Self::Map { - self.tcx.hir() + fn maybe_tcx(&mut self) -> Self::MaybeTyCtxt { + self.tcx } fn visit_expr(&mut self, ex: &'tcx hir::Expr<'tcx>) -> Self::Result { if let hir::ExprKind::Closure(closure) = ex.kind { @@ -494,9 +482,9 @@ fn best_definition_site_of_opaque<'tcx>( None } hir::OpaqueTyOrigin::TyAlias { in_assoc_ty: false, .. } => { - let scope = tcx.hir().get_defining_scope(tcx.local_def_id_to_hir_id(opaque_def_id)); + let scope = tcx.hir_get_defining_scope(tcx.local_def_id_to_hir_id(opaque_def_id)); let found = if scope == hir::CRATE_HIR_ID { - tcx.hir().walk_toplevel_module(&mut locator) + tcx.hir_walk_toplevel_module(&mut locator) } else { match tcx.hir_node(scope) { Node::Item(it) => locator.visit_item(it), @@ -892,7 +880,7 @@ pub(crate) fn check_item_type(tcx: TyCtxt<'_>, def_id: LocalDefId) { .emit(); } - let item = tcx.hir().foreign_item(item.id); + let item = tcx.hir_foreign_item(item.id); match &item.kind { hir::ForeignItemKind::Fn(sig, _, _) => { require_c_abi_if_c_variadic(tcx, sig.decl, abi, item.span); @@ -907,13 +895,6 @@ pub(crate) fn check_item_type(tcx: TyCtxt<'_>, def_id: LocalDefId) { } } } - DefKind::GlobalAsm => { - let it = tcx.hir().expect_item(def_id); - let hir::ItemKind::GlobalAsm(asm) = it.kind else { - span_bug!(it.span, "DefKind::GlobalAsm but got {:#?}", it) - }; - InlineAsmCtxt::new_global_asm(tcx).check_asm(asm, def_id); - } _ => {} } } @@ -1011,6 +992,32 @@ fn check_impl_items_against_trait<'tcx>( let trait_def = tcx.trait_def(trait_ref.def_id); + let infcx = tcx.infer_ctxt().ignoring_regions().build(TypingMode::non_body_analysis()); + + let ocx = ObligationCtxt::new_with_diagnostics(&infcx); + let cause = ObligationCause::misc(tcx.def_span(impl_id), impl_id); + let param_env = tcx.param_env(impl_id); + + let self_is_guaranteed_unsized = match tcx + .struct_tail_raw( + trait_ref.self_ty(), + |ty| { + ocx.structurally_normalize_ty(&cause, param_env, ty).unwrap_or_else(|_| { + Ty::new_error_with_message( + tcx, + tcx.def_span(impl_id), + "struct tail should be computable", + ) + }) + }, + || (), + ) + .kind() + { + ty::Dynamic(_, _, ty::DynKind::Dyn) | ty::Slice(_) | ty::Str => true, + _ => false, + }; + for &impl_item in impl_item_refs { let ty_impl_item = tcx.associated_item(impl_item); let ty_trait_item = if let Some(trait_item_id) = ty_impl_item.trait_item_def_id { @@ -1040,6 +1047,15 @@ fn check_impl_items_against_trait<'tcx>( } } + if self_is_guaranteed_unsized && tcx.generics_require_sized_self(ty_trait_item.def_id) { + tcx.emit_node_span_lint( + rustc_lint_defs::builtin::DEAD_CODE, + tcx.local_def_id_to_hir_id(ty_impl_item.def_id.expect_local()), + tcx.def_span(ty_impl_item.def_id), + errors::UselessImplItem, + ) + } + check_specialization_validity( tcx, trait_def, @@ -1063,7 +1079,11 @@ fn check_impl_items_against_trait<'tcx>( .as_ref() .is_some_and(|node_item| node_item.item.defaultness(tcx).has_value()); - if !is_implemented && tcx.defaultness(impl_id).is_final() { + if !is_implemented + && tcx.defaultness(impl_id).is_final() + // unsized types don't need to implement methods that have `Self: Sized` bounds. + && !(self_is_guaranteed_unsized && tcx.generics_require_sized_self(trait_item_id)) + { missing_items.push(tcx.associated_item(trait_item_id)); } @@ -1135,7 +1155,7 @@ fn check_impl_items_against_trait<'tcx>( if let Some(missing_items) = must_implement_one_of { let attr_span = tcx .get_attr(trait_ref.def_id, sym::rustc_must_implement_one_of) - .map(|attr| attr.span); + .map(|attr| attr.span()); missing_items_must_implement_one_of_err( tcx, @@ -1224,11 +1244,13 @@ fn check_simd(tcx: TyCtxt<'_>, sp: Span, def_id: LocalDefId) { pub(super) fn check_packed(tcx: TyCtxt<'_>, sp: Span, def: ty::AdtDef<'_>) { let repr = def.repr(); if repr.packed() { - for attr in tcx.get_attrs(def.did(), sym::repr) { - for r in attr::parse_repr_attr(tcx.sess, attr) { - if let attr::ReprPacked(pack) = r + if let Some(reprs) = + attr::find_attr!(tcx.get_all_attrs(def.did()), AttributeKind::Repr(r) => r) + { + for (r, _) in reprs { + if let ReprPacked(pack) = r && let Some(repr_pack) = repr.pack - && pack != repr_pack + && pack != &repr_pack { struct_span_code_err!( tcx.dcx(), @@ -1440,16 +1462,19 @@ fn check_enum(tcx: TyCtxt<'_>, def_id: LocalDefId) { def.destructor(tcx); // force the destructor to be evaluated if def.variants().is_empty() { - if let Some(attr) = tcx.get_attrs(def_id, sym::repr).next() { - struct_span_code_err!( - tcx.dcx(), - attr.span, - E0084, - "unsupported representation for zero-variant enum" - ) - .with_span_label(tcx.def_span(def_id), "zero-variant enum") - .emit(); - } + attr::find_attr!( + tcx.get_all_attrs(def_id), + AttributeKind::Repr(rs) => { + struct_span_code_err!( + tcx.dcx(), + rs.first().unwrap().1, + E0084, + "unsupported representation for zero-variant enum" + ) + .with_span_label(tcx.def_span(def_id), "zero-variant enum") + .emit(); + } + ); } let repr_type_ty = def.repr().discr_type().to_ty(tcx); @@ -1506,7 +1531,7 @@ fn detect_discriminant_duplicate<'tcx>(tcx: TyCtxt<'tcx>, adt: ty::AdtDef<'tcx>) // In the case the discriminant is both a duplicate and overflowed, let the user know if let hir::Node::AnonConst(expr) = tcx.hir_node_by_def_id(discr_def_id.expect_local()) - && let hir::ExprKind::Lit(lit) = &tcx.hir().body(expr.body).value.kind + && let hir::ExprKind::Lit(lit) = &tcx.hir_body(expr.body).value.kind && let rustc_ast::LitKind::Int(lit_value, _int_kind) = &lit.node && *lit_value != dis.val { |