// FIXME(jdonszelmann): should become rustc_attr_validation //! This module implements some validity checks for attributes. //! In particular it verifies that `#[inline]` and `#[repr]` attributes are //! attached to items that actually support them and if there are //! conflicts between multiple such attributes attached to the same //! item. use std::cell::Cell; use std::collections::hash_map::Entry; use std::slice; use rustc_abi::{Align, ExternAbi, Size}; use rustc_ast::{AttrStyle, LitKind, MetaItemInner, MetaItemKind, ast}; use rustc_attr_parsing::{AttributeParser, Late}; use rustc_data_structures::fx::FxHashMap; use rustc_errors::{Applicability, DiagCtxtHandle, IntoDiagArg, MultiSpan, StashKey}; use rustc_feature::{ ACCEPTED_LANG_FEATURES, AttributeDuplicates, AttributeType, BUILTIN_ATTRIBUTE_MAP, BuiltinAttribute, }; use rustc_hir::attrs::{AttributeKind, InlineAttr, MirDialect, MirPhase, ReprAttr, SanitizerSet}; use rustc_hir::def::DefKind; use rustc_hir::def_id::LocalModDefId; use rustc_hir::intravisit::{self, Visitor}; use rustc_hir::{ self as hir, Attribute, CRATE_HIR_ID, CRATE_OWNER_ID, FnSig, ForeignItem, HirId, Item, ItemKind, MethodKind, PartialConstStability, Safety, Stability, StabilityLevel, Target, TraitItem, find_attr, }; use rustc_macros::LintDiagnostic; use rustc_middle::hir::nested_filter; use rustc_middle::middle::resolve_bound_vars::ObjectLifetimeDefault; use rustc_middle::query::Providers; use rustc_middle::traits::ObligationCause; use rustc_middle::ty::error::{ExpectedFound, TypeError}; use rustc_middle::ty::{self, TyCtxt, TypingMode}; use rustc_middle::{bug, span_bug}; use rustc_session::config::CrateType; use rustc_session::lint; use rustc_session::lint::builtin::{ CONFLICTING_REPR_HINTS, INVALID_DOC_ATTRIBUTES, INVALID_MACRO_EXPORT_ARGUMENTS, MALFORMED_DIAGNOSTIC_ATTRIBUTES, MISPLACED_DIAGNOSTIC_ATTRIBUTES, UNUSED_ATTRIBUTES, }; use rustc_session::parse::feature_err; use rustc_span::edition::Edition; use rustc_span::{BytePos, DUMMY_SP, Span, Symbol, edition, sym}; use rustc_trait_selection::error_reporting::InferCtxtErrorExt; use rustc_trait_selection::infer::{TyCtxtInferExt, ValuePairs}; use rustc_trait_selection::traits::ObligationCtxt; use tracing::debug; use crate::{errors, fluent_generated as fluent}; #[derive(LintDiagnostic)] #[diag(passes_diagnostic_diagnostic_on_unimplemented_only_for_traits)] struct DiagnosticOnUnimplementedOnlyForTraits; fn target_from_impl_item<'tcx>(tcx: TyCtxt<'tcx>, impl_item: &hir::ImplItem<'_>) -> Target { match impl_item.kind { hir::ImplItemKind::Const(..) => Target::AssocConst, hir::ImplItemKind::Fn(..) => { let parent_def_id = tcx.hir_get_parent_item(impl_item.hir_id()).def_id; let containing_item = tcx.hir_expect_item(parent_def_id); let containing_impl_is_for_trait = match &containing_item.kind { hir::ItemKind::Impl(impl_) => impl_.of_trait.is_some(), _ => bug!("parent of an ImplItem must be an Impl"), }; if containing_impl_is_for_trait { Target::Method(MethodKind::Trait { body: true }) } else { Target::Method(MethodKind::Inherent) } } hir::ImplItemKind::Type(..) => Target::AssocTy, } } #[derive(Clone, Copy)] enum ItemLike<'tcx> { Item(&'tcx Item<'tcx>), ForeignItem, } #[derive(Copy, Clone)] pub(crate) enum ProcMacroKind { FunctionLike, Derive, Attribute, } impl IntoDiagArg for ProcMacroKind { fn into_diag_arg(self, _: &mut Option) -> rustc_errors::DiagArgValue { match self { ProcMacroKind::Attribute => "attribute proc macro", ProcMacroKind::Derive => "derive proc macro", ProcMacroKind::FunctionLike => "function-like proc macro", } .into_diag_arg(&mut None) } } #[derive(Clone, Copy)] enum DocFakeItemKind { Attribute, Keyword, } impl DocFakeItemKind { fn name(self) -> &'static str { match self { Self::Attribute => "attribute", Self::Keyword => "keyword", } } } struct CheckAttrVisitor<'tcx> { tcx: TyCtxt<'tcx>, // Whether or not this visitor should abort after finding errors abort: Cell, } impl<'tcx> CheckAttrVisitor<'tcx> { fn dcx(&self) -> DiagCtxtHandle<'tcx> { self.tcx.dcx() } /// Checks any attribute. fn check_attributes( &self, hir_id: HirId, span: Span, target: Target, item: Option>, ) { let mut doc_aliases = FxHashMap::default(); let mut specified_inline = None; let mut seen = FxHashMap::default(); let attrs = self.tcx.hir_attrs(hir_id); for attr in attrs { let mut style = None; match attr { Attribute::Parsed(AttributeKind::ProcMacro(_)) => { self.check_proc_macro(hir_id, target, ProcMacroKind::FunctionLike) } Attribute::Parsed(AttributeKind::ProcMacroAttribute(_)) => { self.check_proc_macro(hir_id, target, ProcMacroKind::Attribute); } Attribute::Parsed(AttributeKind::ProcMacroDerive { .. }) => { self.check_proc_macro(hir_id, target, ProcMacroKind::Derive) } &Attribute::Parsed(AttributeKind::TypeConst(attr_span)) => { self.check_type_const(hir_id, attr_span, target) } Attribute::Parsed( AttributeKind::Stability { span: attr_span, stability: Stability { level, feature }, } | AttributeKind::ConstStability { span: attr_span, stability: PartialConstStability { level, feature, .. }, }, ) => self.check_stability(*attr_span, span, level, *feature), Attribute::Parsed(AttributeKind::Inline(InlineAttr::Force { .. }, ..)) => {} // handled separately below Attribute::Parsed(AttributeKind::Inline(kind, attr_span)) => { self.check_inline(hir_id, *attr_span, kind, target) } Attribute::Parsed(AttributeKind::LoopMatch(attr_span)) => { self.check_loop_match(hir_id, *attr_span, target) } Attribute::Parsed(AttributeKind::ConstContinue(attr_span)) => { self.check_const_continue(hir_id, *attr_span, target) } Attribute::Parsed(AttributeKind::AllowInternalUnsafe(attr_span) | AttributeKind::AllowInternalUnstable(.., attr_span)) => { self.check_macro_only_attr(*attr_span, span, target, attrs) } Attribute::Parsed(AttributeKind::AllowConstFnUnstable(_, first_span)) => { self.check_rustc_allow_const_fn_unstable(hir_id, *first_span, span, target) } Attribute::Parsed(AttributeKind::Deprecation { .. }) => { self.check_deprecated(hir_id, attr, span, target) } Attribute::Parsed(AttributeKind::TargetFeature{ attr_span, ..}) => { self.check_target_feature(hir_id, *attr_span, target, attrs) } Attribute::Parsed(AttributeKind::RustcObjectLifetimeDefault) => { self.check_object_lifetime_default(hir_id); } &Attribute::Parsed(AttributeKind::PubTransparent(attr_span)) => { self.check_rustc_pub_transparent(attr_span, span, attrs) } Attribute::Parsed(AttributeKind::Align { align, span: attr_span }) => { self.check_align(*align, *attr_span) } Attribute::Parsed(AttributeKind::Naked(..)) => { self.check_naked(hir_id, target) } Attribute::Parsed(AttributeKind::TrackCaller(attr_span)) => { self.check_track_caller(hir_id, *attr_span, attrs, target) } Attribute::Parsed(AttributeKind::NonExhaustive(attr_span)) => { self.check_non_exhaustive(*attr_span, span, target, item) } &Attribute::Parsed(AttributeKind::FfiPure(attr_span)) => { self.check_ffi_pure(attr_span, attrs) } Attribute::Parsed(AttributeKind::MayDangle(attr_span)) => { self.check_may_dangle(hir_id, *attr_span) } &Attribute::Parsed(AttributeKind::CustomMir(dialect, phase, attr_span)) => { self.check_custom_mir(dialect, phase, attr_span) } &Attribute::Parsed(AttributeKind::Sanitize { on_set, off_set, span: attr_span}) => { self.check_sanitize(attr_span, on_set | off_set, span, target); }, Attribute::Parsed(AttributeKind::Link(_, attr_span)) => { self.check_link(hir_id, *attr_span, span, target) } Attribute::Parsed( AttributeKind::BodyStability { .. } | AttributeKind::ConstStabilityIndirect | AttributeKind::MacroTransparency(_) | AttributeKind::Pointee(..) | AttributeKind::Dummy | AttributeKind::RustcBuiltinMacro { .. } | AttributeKind::Ignore { .. } | AttributeKind::Path(..) | AttributeKind::NoImplicitPrelude(..) | AttributeKind::AutomaticallyDerived(..) | AttributeKind::Marker(..) | AttributeKind::SkipDuringMethodDispatch { .. } | AttributeKind::Coinductive(..) | AttributeKind::ConstTrait(..) | AttributeKind::DenyExplicitImpl(..) | AttributeKind::DoNotImplementViaObject(..) | AttributeKind::SpecializationTrait(..) | AttributeKind::UnsafeSpecializationMarker(..) | AttributeKind::ParenSugar(..) | AttributeKind::AllowIncoherentImpl(..) | AttributeKind::Confusables { .. } // `#[doc]` is actually a lot more than just doc comments, so is checked below | AttributeKind::DocComment {..} // handled below this loop and elsewhere | AttributeKind::Repr { .. } | AttributeKind::Cold(..) | AttributeKind::ExportName { .. } | AttributeKind::CoherenceIsCore | AttributeKind::Fundamental | AttributeKind::Optimize(..) | AttributeKind::LinkSection { .. } | AttributeKind::MacroUse { .. } | AttributeKind::MacroEscape( .. ) | AttributeKind::RustcLayoutScalarValidRangeStart(..) | AttributeKind::RustcLayoutScalarValidRangeEnd(..) | AttributeKind::ExportStable | AttributeKind::FfiConst(..) | AttributeKind::UnstableFeatureBound(..) | AttributeKind::AsPtr(..) | AttributeKind::LinkName { .. } | AttributeKind::LinkOrdinal { .. } | AttributeKind::NoMangle(..) | AttributeKind::Used { .. } | AttributeKind::PassByValue (..) | AttributeKind::StdInternalSymbol (..) | AttributeKind::Coverage (..) | AttributeKind::ShouldPanic { .. } | AttributeKind::Coroutine(..) | AttributeKind::Linkage(..) | AttributeKind::MustUse { .. } | AttributeKind::CrateName { .. } | AttributeKind::RecursionLimit { .. } | AttributeKind::MoveSizeLimit { .. } | AttributeKind::TypeLengthLimit { .. } | AttributeKind::PatternComplexityLimit { .. } ) => { /* do nothing */ } Attribute::Unparsed(attr_item) => { style = Some(attr_item.style); match attr.path().as_slice() { [sym::diagnostic, sym::do_not_recommend, ..] => { self.check_do_not_recommend(attr.span(), hir_id, target, attr, item) } [sym::diagnostic, sym::on_unimplemented, ..] => { self.check_diagnostic_on_unimplemented(attr.span(), hir_id, target) } [sym::thread_local, ..] => self.check_thread_local(attr, span, target), [sym::doc, ..] => self.check_doc_attrs( attr, attr_item.style, hir_id, target, &mut specified_inline, &mut doc_aliases, ), [sym::no_link, ..] => self.check_no_link(hir_id, attr, span, target), [sym::debugger_visualizer, ..] => self.check_debugger_visualizer(attr, target), [sym::rustc_no_implicit_autorefs, ..] => { self.check_applied_to_fn_or_method(hir_id, attr.span(), span, target) } [sym::rustc_never_returns_null_ptr, ..] => { self.check_applied_to_fn_or_method(hir_id, attr.span(), span, target) } [sym::rustc_legacy_const_generics, ..] => { self.check_rustc_legacy_const_generics(hir_id, attr, span, target, item) } [sym::rustc_lint_query_instability, ..] => { self.check_applied_to_fn_or_method(hir_id, attr.span(), span, target) } [sym::rustc_lint_untracked_query_information, ..] => { self.check_applied_to_fn_or_method(hir_id, attr.span(), span, target) } [sym::rustc_lint_diagnostics, ..] => { self.check_applied_to_fn_or_method(hir_id, attr.span(), span, target) } [sym::rustc_lint_opt_ty, ..] => self.check_rustc_lint_opt_ty(attr, span, target), [sym::rustc_lint_opt_deny_field_access, ..] => { self.check_rustc_lint_opt_deny_field_access(attr, span, target) } [sym::rustc_clean, ..] | [sym::rustc_dirty, ..] | [sym::rustc_if_this_changed, ..] | [sym::rustc_then_this_would_need, ..] => self.check_rustc_dirty_clean(attr), [sym::rustc_must_implement_one_of, ..] => self.check_must_be_applied_to_trait(attr.span(), span, target), [sym::collapse_debuginfo, ..] => self.check_collapse_debuginfo(attr, span, target), [sym::must_not_suspend, ..] => self.check_must_not_suspend(attr, span, target), [sym::rustc_has_incoherent_inherent_impls, ..] => { self.check_has_incoherent_inherent_impls(attr, span, target) } [sym::macro_export, ..] => self.check_macro_export(hir_id, attr, target), [sym::autodiff_forward, ..] | [sym::autodiff_reverse, ..] => { self.check_autodiff(hir_id, attr, span, target) } [ // ok sym::allow | sym::expect | sym::warn | sym::deny | sym::forbid | sym::cfg | sym::cfg_attr | sym::cfg_trace | sym::cfg_attr_trace // need to be fixed | sym::cfi_encoding // FIXME(cfi_encoding) | sym::instruction_set // broken on stable!!! | sym::windows_subsystem // broken on stable!!! | sym::patchable_function_entry // FIXME(patchable_function_entry) | sym::deprecated_safe // FIXME(deprecated_safe) // internal | sym::prelude_import | sym::panic_handler | sym::lang | sym::needs_allocator | sym::default_lib_allocator, .. ] => {} [name, rest@..] => { match BUILTIN_ATTRIBUTE_MAP.get(name) { // checked below Some(BuiltinAttribute { type_: AttributeType::CrateLevel, .. }) => {} Some(_) => { if rest.len() > 0 && AttributeParser::::is_parsed_attribute(slice::from_ref(name)) { // Check if we tried to use a builtin attribute as an attribute namespace, like `#[must_use::skip]`. // This check is here to solve https://github.com/rust-lang/rust/issues/137590 // An error is already produced for this case elsewhere continue } // FIXME: differentiate between unstable and internal attributes just // like we do with features instead of just accepting `rustc_` // attributes by name. That should allow trimming the above list, too. if !name.as_str().starts_with("rustc_") { span_bug!( attr.span(), "builtin attribute {name:?} not handled by `CheckAttrVisitor`" ) } } None => (), } } [] => unreachable!(), } } } let builtin = attr.ident().and_then(|ident| BUILTIN_ATTRIBUTE_MAP.get(&ident.name)); if hir_id != CRATE_HIR_ID { match attr { Attribute::Parsed(_) => { /* Already validated. */ } Attribute::Unparsed(attr) => { // FIXME(jdonszelmann): remove once all crate-level attrs are parsed and caught by // the above if let Some(BuiltinAttribute { type_: AttributeType::CrateLevel, .. }) = attr.path .segments .first() .and_then(|ident| BUILTIN_ATTRIBUTE_MAP.get(&ident.name)) { match attr.style { ast::AttrStyle::Outer => { let attr_span = attr.span; let bang_position = self .tcx .sess .source_map() .span_until_char(attr_span, '[') .shrink_to_hi(); self.tcx.emit_node_span_lint( UNUSED_ATTRIBUTES, hir_id, attr.span, errors::OuterCrateLevelAttr { suggestion: errors::OuterCrateLevelAttrSuggestion { bang_position, }, }, ) } ast::AttrStyle::Inner => self.tcx.emit_node_span_lint( UNUSED_ATTRIBUTES, hir_id, attr.span, errors::InnerCrateLevelAttr, ), } } } } } if let Some(BuiltinAttribute { duplicates, .. }) = builtin { check_duplicates(self.tcx, attr, hir_id, *duplicates, &mut seen); } self.check_unused_attribute(hir_id, attr, style) } self.check_repr(attrs, span, target, item, hir_id); self.check_rustc_force_inline(hir_id, attrs, target); self.check_mix_no_mangle_export(hir_id, attrs); } fn inline_attr_str_error_with_macro_def(&self, hir_id: HirId, attr_span: Span, sym: &str) { self.tcx.emit_node_span_lint( UNUSED_ATTRIBUTES, hir_id, attr_span, errors::IgnoredAttrWithMacro { sym }, ); } /// Checks if `#[diagnostic::do_not_recommend]` is applied on a trait impl and that it has no /// arguments. fn check_do_not_recommend( &self, attr_span: Span, hir_id: HirId, target: Target, attr: &Attribute, item: Option>, ) { if !matches!(target, Target::Impl { .. }) || matches!( item, Some(ItemLike::Item(hir::Item { kind: hir::ItemKind::Impl(_impl),.. })) if _impl.of_trait.is_none() ) { self.tcx.emit_node_span_lint( MISPLACED_DIAGNOSTIC_ATTRIBUTES, hir_id, attr_span, errors::IncorrectDoNotRecommendLocation, ); } if !attr.is_word() { self.tcx.emit_node_span_lint( MALFORMED_DIAGNOSTIC_ATTRIBUTES, hir_id, attr_span, errors::DoNotRecommendDoesNotExpectArgs, ); } } /// Checks if `#[diagnostic::on_unimplemented]` is applied to a trait definition fn check_diagnostic_on_unimplemented(&self, attr_span: Span, hir_id: HirId, target: Target) { if !matches!(target, Target::Trait) { self.tcx.emit_node_span_lint( MISPLACED_DIAGNOSTIC_ATTRIBUTES, hir_id, attr_span, DiagnosticOnUnimplementedOnlyForTraits, ); } } /// Checks if an `#[inline]` is applied to a function or a closure. fn check_inline(&self, hir_id: HirId, attr_span: Span, kind: &InlineAttr, target: Target) { match target { Target::Fn | Target::Closure | Target::Method(MethodKind::Trait { body: true } | MethodKind::Inherent) => { // `#[inline]` is ignored if the symbol must be codegened upstream because it's exported. if let Some(did) = hir_id.as_owner() && self.tcx.def_kind(did).has_codegen_attrs() && kind != &InlineAttr::Never { let attrs = self.tcx.codegen_fn_attrs(did); // Not checking naked as `#[inline]` is forbidden for naked functions anyways. if attrs.contains_extern_indicator() { self.tcx.emit_node_span_lint( UNUSED_ATTRIBUTES, hir_id, attr_span, errors::InlineIgnoredForExported {}, ); } } } _ => {} } } /// Checks that the `#[sanitize(..)]` attribute is applied to a /// function/closure/method, or to an impl block or module. fn check_sanitize( &self, attr_span: Span, set: SanitizerSet, target_span: Span, target: Target, ) { let mut not_fn_impl_mod = None; let mut no_body = None; match target { Target::Fn | Target::Closure | Target::Method(MethodKind::Trait { body: true } | MethodKind::Inherent) | Target::Impl { .. } | Target::Mod => return, Target::Static // if we mask out the address bits, i.e. *only* address was set, // we allow it if set & !(SanitizerSet::ADDRESS | SanitizerSet::KERNELADDRESS) == SanitizerSet::empty() => { return; } // These are "functions", but they aren't allowed because they don't // have a body, so the usual explanation would be confusing. Target::Method(MethodKind::Trait { body: false }) | Target::ForeignFn => { no_body = Some(target_span); } _ => { not_fn_impl_mod = Some(target_span); } } self.dcx().emit_err(errors::SanitizeAttributeNotAllowed { attr_span, not_fn_impl_mod, no_body, help: (), }); } /// Checks if `#[naked]` is applied to a function definition. fn check_naked(&self, hir_id: HirId, target: Target) { match target { Target::Fn | Target::Method(MethodKind::Trait { body: true } | MethodKind::Inherent) => { let fn_sig = self.tcx.hir_node(hir_id).fn_sig().unwrap(); let abi = fn_sig.header.abi; if abi.is_rustic_abi() && !self.tcx.features().naked_functions_rustic_abi() { feature_err( &self.tcx.sess, sym::naked_functions_rustic_abi, fn_sig.span, format!( "`#[naked]` is currently unstable on `extern \"{}\"` functions", abi.as_str() ), ) .emit(); } } _ => {} } } /// Debugging aid for `object_lifetime_default` query. fn check_object_lifetime_default(&self, hir_id: HirId) { let tcx = self.tcx; if let Some(owner_id) = hir_id.as_owner() && let Some(generics) = tcx.hir_get_generics(owner_id.def_id) { for p in generics.params { let hir::GenericParamKind::Type { .. } = p.kind else { continue }; let default = tcx.object_lifetime_default(p.def_id); let repr = match default { ObjectLifetimeDefault::Empty => "BaseDefault".to_owned(), ObjectLifetimeDefault::Static => "'static".to_owned(), ObjectLifetimeDefault::Param(def_id) => tcx.item_name(def_id).to_string(), ObjectLifetimeDefault::Ambiguous => "Ambiguous".to_owned(), }; tcx.dcx().emit_err(errors::ObjectLifetimeErr { span: p.span, repr }); } } } /// Checks if `#[collapse_debuginfo]` is applied to a macro. fn check_collapse_debuginfo(&self, attr: &Attribute, span: Span, target: Target) { match target { Target::MacroDef => {} _ => { self.tcx.dcx().emit_err(errors::CollapseDebuginfo { attr_span: attr.span(), defn_span: span, }); } } } /// Checks if a `#[track_caller]` is applied to a function. fn check_track_caller( &self, hir_id: HirId, attr_span: Span, attrs: &[Attribute], target: Target, ) { match target { Target::Fn => { // `#[track_caller]` is not valid on weak lang items because they are called via // `extern` declarations and `#[track_caller]` would alter their ABI. if let Some((lang_item, _)) = hir::lang_items::extract(attrs) && let Some(item) = hir::LangItem::from_name(lang_item) && item.is_weak() { let sig = self.tcx.hir_node(hir_id).fn_sig().unwrap(); self.dcx().emit_err(errors::LangItemWithTrackCaller { attr_span, name: lang_item, sig_span: sig.span, }); } } _ => {} } } /// Checks if the `#[non_exhaustive]` attribute on an `item` is valid. fn check_non_exhaustive( &self, attr_span: Span, span: Span, target: Target, item: Option>, ) { match target { Target::Struct => { if let Some(ItemLike::Item(hir::Item { kind: hir::ItemKind::Struct(_, _, hir::VariantData::Struct { fields, .. }), .. })) = item && !fields.is_empty() && fields.iter().any(|f| f.default.is_some()) { self.dcx().emit_err(errors::NonExhaustiveWithDefaultFieldValues { attr_span, defn_span: span, }); } } _ => {} } } /// Checks if the `#[target_feature]` attribute on `item` is valid. fn check_target_feature( &self, hir_id: HirId, attr_span: Span, target: Target, attrs: &[Attribute], ) { match target { Target::Method(MethodKind::Trait { body: true } | MethodKind::Inherent) | Target::Fn => { // `#[target_feature]` is not allowed in lang items. if let Some((lang_item, _)) = hir::lang_items::extract(attrs) // Calling functions with `#[target_feature]` is // not unsafe on WASM, see #84988 && !self.tcx.sess.target.is_like_wasm && !self.tcx.sess.opts.actually_rustdoc { let sig = self.tcx.hir_node(hir_id).fn_sig().unwrap(); self.dcx().emit_err(errors::LangItemWithTargetFeature { attr_span, name: lang_item, sig_span: sig.span, }); } } _ => {} } } /// Checks if the `#[thread_local]` attribute on `item` is valid. fn check_thread_local(&self, attr: &Attribute, span: Span, target: Target) { match target { Target::ForeignStatic | Target::Static => {} _ => { self.dcx().emit_err(errors::AttrShouldBeAppliedToStatic { attr_span: attr.span(), defn_span: span, }); } } } fn doc_attr_str_error(&self, meta: &MetaItemInner, attr_name: &str) { self.dcx().emit_err(errors::DocExpectStr { attr_span: meta.span(), attr_name }); } fn check_doc_alias_value( &self, meta: &MetaItemInner, doc_alias: Symbol, hir_id: HirId, target: Target, is_list: bool, aliases: &mut FxHashMap, ) { let tcx = self.tcx; let span = meta.name_value_literal_span().unwrap_or_else(|| meta.span()); let attr_str = &format!("`#[doc(alias{})]`", if is_list { "(\"...\")" } else { " = \"...\"" }); if doc_alias == sym::empty { tcx.dcx().emit_err(errors::DocAliasEmpty { span, attr_str }); return; } let doc_alias_str = doc_alias.as_str(); if let Some(c) = doc_alias_str .chars() .find(|&c| c == '"' || c == '\'' || (c.is_whitespace() && c != ' ')) { tcx.dcx().emit_err(errors::DocAliasBadChar { span, attr_str, char_: c }); return; } if doc_alias_str.starts_with(' ') || doc_alias_str.ends_with(' ') { tcx.dcx().emit_err(errors::DocAliasStartEnd { span, attr_str }); return; } let span = meta.span(); if let Some(location) = match target { Target::AssocTy => { if let DefKind::Impl { .. } = self.tcx.def_kind(self.tcx.local_parent(hir_id.owner.def_id)) { Some("type alias in implementation block") } else { None } } Target::AssocConst => { let parent_def_id = self.tcx.hir_get_parent_item(hir_id).def_id; let containing_item = self.tcx.hir_expect_item(parent_def_id); // We can't link to trait impl's consts. let err = "associated constant in trait implementation block"; match containing_item.kind { ItemKind::Impl(hir::Impl { of_trait: Some(_), .. }) => Some(err), _ => None, } } // we check the validity of params elsewhere Target::Param => return, Target::Expression | Target::Statement | Target::Arm | Target::ForeignMod | Target::Closure | Target::Impl { .. } | Target::WherePredicate => Some(target.name()), Target::ExternCrate | Target::Use | Target::Static | Target::Const | Target::Fn | Target::Mod | Target::GlobalAsm | Target::TyAlias | Target::Enum | Target::Variant | Target::Struct | Target::Field | Target::Union | Target::Trait | Target::TraitAlias | Target::Method(..) | Target::ForeignFn | Target::ForeignStatic | Target::ForeignTy | Target::GenericParam { .. } | Target::MacroDef | Target::PatField | Target::ExprField | Target::Crate | Target::MacroCall | Target::Delegation { .. } => None, } { tcx.dcx().emit_err(errors::DocAliasBadLocation { span, attr_str, location }); return; } if self.tcx.hir_opt_name(hir_id) == Some(doc_alias) { tcx.dcx().emit_err(errors::DocAliasNotAnAlias { span, attr_str }); return; } if let Err(entry) = aliases.try_insert(doc_alias_str.to_owned(), span) { self.tcx.emit_node_span_lint( UNUSED_ATTRIBUTES, hir_id, span, errors::DocAliasDuplicated { first_defn: *entry.entry.get() }, ); } } fn check_doc_alias( &self, meta: &MetaItemInner, hir_id: HirId, target: Target, aliases: &mut FxHashMap, ) { if let Some(values) = meta.meta_item_list() { for v in values { match v.lit() { Some(l) => match l.kind { LitKind::Str(s, _) => { self.check_doc_alias_value(v, s, hir_id, target, true, aliases); } _ => { self.tcx .dcx() .emit_err(errors::DocAliasNotStringLiteral { span: v.span() }); } }, None => { self.tcx .dcx() .emit_err(errors::DocAliasNotStringLiteral { span: v.span() }); } } } } else if let Some(doc_alias) = meta.value_str() { self.check_doc_alias_value(meta, doc_alias, hir_id, target, false, aliases) } else { self.dcx().emit_err(errors::DocAliasMalformed { span: meta.span() }); } } fn check_doc_keyword_and_attribute( &self, meta: &MetaItemInner, hir_id: HirId, attr_kind: DocFakeItemKind, ) { fn is_doc_keyword(s: Symbol) -> bool { // FIXME: Once rustdoc can handle URL conflicts on case insensitive file systems, we // can remove the `SelfTy` case here, remove `sym::SelfTy`, and update the // `#[doc(keyword = "SelfTy")` attribute in `library/std/src/keyword_docs.rs`. s.is_reserved(|| edition::LATEST_STABLE_EDITION) || s.is_weak() || s == sym::SelfTy } // FIXME: This should support attributes with namespace like `diagnostic::do_not_recommend`. fn is_builtin_attr(s: Symbol) -> bool { rustc_feature::BUILTIN_ATTRIBUTE_MAP.contains_key(&s) } let value = match meta.value_str() { Some(value) if value != sym::empty => value, _ => return self.doc_attr_str_error(meta, attr_kind.name()), }; let item_kind = match self.tcx.hir_node(hir_id) { hir::Node::Item(item) => Some(&item.kind), _ => None, }; match item_kind { Some(ItemKind::Mod(_, module)) => { if !module.item_ids.is_empty() { self.dcx().emit_err(errors::DocKeywordAttributeEmptyMod { span: meta.span(), attr_name: attr_kind.name(), }); return; } } _ => { self.dcx().emit_err(errors::DocKeywordAttributeNotMod { span: meta.span(), attr_name: attr_kind.name(), }); return; } } match attr_kind { DocFakeItemKind::Keyword => { if !is_doc_keyword(value) { self.dcx().emit_err(errors::DocKeywordNotKeyword { span: meta.name_value_literal_span().unwrap_or_else(|| meta.span()), keyword: value, }); } } DocFakeItemKind::Attribute => { if !is_builtin_attr(value) { self.dcx().emit_err(errors::DocAttributeNotAttribute { span: meta.name_value_literal_span().unwrap_or_else(|| meta.span()), attribute: value, }); } } } } fn check_doc_fake_variadic(&self, meta: &MetaItemInner, hir_id: HirId) { let item_kind = match self.tcx.hir_node(hir_id) { hir::Node::Item(item) => Some(&item.kind), _ => None, }; match item_kind { Some(ItemKind::Impl(i)) => { let is_valid = doc_fake_variadic_is_allowed_self_ty(i.self_ty) || if let Some(&[hir::GenericArg::Type(ty)]) = i .of_trait .and_then(|of_trait| of_trait.trait_ref.path.segments.last()) .map(|last_segment| last_segment.args().args) { matches!(&ty.kind, hir::TyKind::Tup([_])) } else { false }; if !is_valid { self.dcx().emit_err(errors::DocFakeVariadicNotValid { span: meta.span() }); } } _ => { self.dcx().emit_err(errors::DocKeywordOnlyImpl { span: meta.span() }); } } } fn check_doc_search_unbox(&self, meta: &MetaItemInner, hir_id: HirId) { let hir::Node::Item(item) = self.tcx.hir_node(hir_id) else { self.dcx().emit_err(errors::DocSearchUnboxInvalid { span: meta.span() }); return; }; match item.kind { ItemKind::Enum(_, generics, _) | ItemKind::Struct(_, generics, _) if generics.params.len() != 0 => {} ItemKind::Trait(_, _, _, _, generics, _, items) if generics.params.len() != 0 || items.iter().any(|item| { matches!(self.tcx.def_kind(item.owner_id), DefKind::AssocTy) }) => {} ItemKind::TyAlias(_, generics, _) if generics.params.len() != 0 => {} _ => { self.dcx().emit_err(errors::DocSearchUnboxInvalid { span: meta.span() }); } } } /// Checks `#[doc(inline)]`/`#[doc(no_inline)]` attributes. /// /// A doc inlining attribute is invalid if it is applied to a non-`use` item, or /// if there are conflicting attributes for one item. /// /// `specified_inline` is used to keep track of whether we have /// already seen an inlining attribute for this item. /// If so, `specified_inline` holds the value and the span of /// the first `inline`/`no_inline` attribute. fn check_doc_inline( &self, style: AttrStyle, meta: &MetaItemInner, hir_id: HirId, target: Target, specified_inline: &mut Option<(bool, Span)>, ) { match target { Target::Use | Target::ExternCrate => { let do_inline = meta.has_name(sym::inline); if let Some((prev_inline, prev_span)) = *specified_inline { if do_inline != prev_inline { let mut spans = MultiSpan::from_spans(vec![prev_span, meta.span()]); spans.push_span_label(prev_span, fluent::passes_doc_inline_conflict_first); spans.push_span_label( meta.span(), fluent::passes_doc_inline_conflict_second, ); self.dcx().emit_err(errors::DocKeywordConflict { spans }); } } else { *specified_inline = Some((do_inline, meta.span())); } } _ => { self.tcx.emit_node_span_lint( INVALID_DOC_ATTRIBUTES, hir_id, meta.span(), errors::DocInlineOnlyUse { attr_span: meta.span(), item_span: (style == AttrStyle::Outer).then(|| self.tcx.hir_span(hir_id)), }, ); } } } fn check_doc_masked( &self, style: AttrStyle, meta: &MetaItemInner, hir_id: HirId, target: Target, ) { if target != Target::ExternCrate { self.tcx.emit_node_span_lint( INVALID_DOC_ATTRIBUTES, hir_id, meta.span(), errors::DocMaskedOnlyExternCrate { attr_span: meta.span(), item_span: (style == AttrStyle::Outer).then(|| self.tcx.hir_span(hir_id)), }, ); return; } if self.tcx.extern_mod_stmt_cnum(hir_id.owner.def_id).is_none() { self.tcx.emit_node_span_lint( INVALID_DOC_ATTRIBUTES, hir_id, meta.span(), errors::DocMaskedNotExternCrateSelf { attr_span: meta.span(), item_span: (style == AttrStyle::Outer).then(|| self.tcx.hir_span(hir_id)), }, ); } } /// Checks that an attribute is *not* used at the crate level. Returns `true` if valid. fn check_attr_not_crate_level( &self, meta: &MetaItemInner, hir_id: HirId, attr_name: &str, ) -> bool { if CRATE_HIR_ID == hir_id { self.dcx().emit_err(errors::DocAttrNotCrateLevel { span: meta.span(), attr_name }); return false; } true } /// Checks that an attribute is used at the crate level. Returns `true` if valid. fn check_attr_crate_level( &self, attr: &Attribute, style: AttrStyle, meta: &MetaItemInner, hir_id: HirId, ) -> bool { if hir_id != CRATE_HIR_ID { // insert a bang between `#` and `[...` let bang_span = attr.span().lo() + BytePos(1); let sugg = (style == AttrStyle::Outer && self.tcx.hir_get_parent_item(hir_id) == CRATE_OWNER_ID) .then_some(errors::AttrCrateLevelOnlySugg { attr: attr.span().with_lo(bang_span).with_hi(bang_span), }); self.tcx.emit_node_span_lint( INVALID_DOC_ATTRIBUTES, hir_id, meta.span(), errors::AttrCrateLevelOnly { sugg }, ); return false; } true } /// Checks that `doc(test(...))` attribute contains only valid attributes and are at the right place. fn check_test_attr( &self, attr: &Attribute, style: AttrStyle, meta: &MetaItemInner, hir_id: HirId, ) { if let Some(metas) = meta.meta_item_list() { for i_meta in metas { match (i_meta.name(), i_meta.meta_item()) { (Some(sym::attr), _) => { // Allowed everywhere like `#[doc]` } (Some(sym::no_crate_inject), _) => { self.check_attr_crate_level(attr, style, meta, hir_id); } (_, Some(m)) => { self.tcx.emit_node_span_lint( INVALID_DOC_ATTRIBUTES, hir_id, i_meta.span(), errors::DocTestUnknown { path: rustc_ast_pretty::pprust::path_to_string(&m.path), }, ); } (_, None) => { self.tcx.emit_node_span_lint( INVALID_DOC_ATTRIBUTES, hir_id, i_meta.span(), errors::DocTestLiteral, ); } } } } else { self.tcx.emit_node_span_lint( INVALID_DOC_ATTRIBUTES, hir_id, meta.span(), errors::DocTestTakesList, ); } } /// Check that the `#![doc(cfg_hide(...))]` attribute only contains a list of attributes. /// fn check_doc_cfg_hide(&self, meta: &MetaItemInner, hir_id: HirId) { if meta.meta_item_list().is_none() { self.tcx.emit_node_span_lint( INVALID_DOC_ATTRIBUTES, hir_id, meta.span(), errors::DocCfgHideTakesList, ); } } /// Runs various checks on `#[doc]` attributes. /// /// `specified_inline` should be initialized to `None` and kept for the scope /// of one item. Read the documentation of [`check_doc_inline`] for more information. /// /// [`check_doc_inline`]: Self::check_doc_inline fn check_doc_attrs( &self, attr: &Attribute, style: AttrStyle, hir_id: HirId, target: Target, specified_inline: &mut Option<(bool, Span)>, aliases: &mut FxHashMap, ) { if let Some(list) = attr.meta_item_list() { for meta in &list { if let Some(i_meta) = meta.meta_item() { match i_meta.name() { Some(sym::alias) => { if self.check_attr_not_crate_level(meta, hir_id, "alias") { self.check_doc_alias(meta, hir_id, target, aliases); } } Some(sym::keyword) => { if self.check_attr_not_crate_level(meta, hir_id, "keyword") { self.check_doc_keyword_and_attribute( meta, hir_id, DocFakeItemKind::Keyword, ); } } Some(sym::attribute) => { if self.check_attr_not_crate_level(meta, hir_id, "attribute") { self.check_doc_keyword_and_attribute( meta, hir_id, DocFakeItemKind::Attribute, ); } } Some(sym::fake_variadic) => { if self.check_attr_not_crate_level(meta, hir_id, "fake_variadic") { self.check_doc_fake_variadic(meta, hir_id); } } Some(sym::search_unbox) => { if self.check_attr_not_crate_level(meta, hir_id, "fake_variadic") { self.check_doc_search_unbox(meta, hir_id); } } Some(sym::test) => { self.check_test_attr(attr, style, meta, hir_id); } Some( sym::html_favicon_url | sym::html_logo_url | sym::html_playground_url | sym::issue_tracker_base_url | sym::html_root_url | sym::html_no_source, ) => { self.check_attr_crate_level(attr, style, meta, hir_id); } Some(sym::cfg_hide) => { if self.check_attr_crate_level(attr, style, meta, hir_id) { self.check_doc_cfg_hide(meta, hir_id); } } Some(sym::inline | sym::no_inline) => { self.check_doc_inline(style, meta, hir_id, target, specified_inline) } Some(sym::masked) => self.check_doc_masked(style, meta, hir_id, target), Some(sym::cfg | sym::hidden | sym::notable_trait) => {} Some(sym::rust_logo) => { if self.check_attr_crate_level(attr, style, meta, hir_id) && !self.tcx.features().rustdoc_internals() { feature_err( &self.tcx.sess, sym::rustdoc_internals, meta.span(), fluent::passes_doc_rust_logo, ) .emit(); } } _ => { let path = rustc_ast_pretty::pprust::path_to_string(&i_meta.path); if i_meta.has_name(sym::spotlight) { self.tcx.emit_node_span_lint( INVALID_DOC_ATTRIBUTES, hir_id, i_meta.span, errors::DocTestUnknownSpotlight { path, span: i_meta.span }, ); } else if i_meta.has_name(sym::include) && let Some(value) = i_meta.value_str() { let applicability = if list.len() == 1 { Applicability::MachineApplicable } else { Applicability::MaybeIncorrect }; // If there are multiple attributes, the suggestion would suggest // deleting all of them, which is incorrect. self.tcx.emit_node_span_lint( INVALID_DOC_ATTRIBUTES, hir_id, i_meta.span, errors::DocTestUnknownInclude { path, value: value.to_string(), inner: match style { AttrStyle::Inner => "!", AttrStyle::Outer => "", }, sugg: (attr.span(), applicability), }, ); } else if i_meta.has_name(sym::passes) || i_meta.has_name(sym::no_default_passes) { self.tcx.emit_node_span_lint( INVALID_DOC_ATTRIBUTES, hir_id, i_meta.span, errors::DocTestUnknownPasses { path, span: i_meta.span }, ); } else if i_meta.has_name(sym::plugins) { self.tcx.emit_node_span_lint( INVALID_DOC_ATTRIBUTES, hir_id, i_meta.span, errors::DocTestUnknownPlugins { path, span: i_meta.span }, ); } else { self.tcx.emit_node_span_lint( INVALID_DOC_ATTRIBUTES, hir_id, i_meta.span, errors::DocTestUnknownAny { path }, ); } } } } else { self.tcx.emit_node_span_lint( INVALID_DOC_ATTRIBUTES, hir_id, meta.span(), errors::DocInvalid, ); } } } } fn check_has_incoherent_inherent_impls(&self, attr: &Attribute, span: Span, target: Target) { match target { Target::Trait | Target::Struct | Target::Enum | Target::Union | Target::ForeignTy => {} _ => { self.tcx .dcx() .emit_err(errors::HasIncoherentInherentImpl { attr_span: attr.span(), span }); } } } fn check_ffi_pure(&self, attr_span: Span, attrs: &[Attribute]) { if find_attr!(attrs, AttributeKind::FfiConst(_)) { // `#[ffi_const]` functions cannot be `#[ffi_pure]` self.dcx().emit_err(errors::BothFfiConstAndPure { attr_span }); } } /// Checks if `#[must_not_suspend]` is applied to a struct, enum, union, or trait. fn check_must_not_suspend(&self, attr: &Attribute, span: Span, target: Target) { match target { Target::Struct | Target::Enum | Target::Union | Target::Trait => {} _ => { self.dcx().emit_err(errors::MustNotSuspend { attr_span: attr.span(), span }); } } } /// Checks if `#[may_dangle]` is applied to a lifetime or type generic parameter in `Drop` impl. fn check_may_dangle(&self, hir_id: HirId, attr_span: Span) { if let hir::Node::GenericParam(param) = self.tcx.hir_node(hir_id) && matches!( param.kind, hir::GenericParamKind::Lifetime { .. } | hir::GenericParamKind::Type { .. } ) && matches!(param.source, hir::GenericParamSource::Generics) && let parent_hir_id = self.tcx.parent_hir_id(hir_id) && let hir::Node::Item(item) = self.tcx.hir_node(parent_hir_id) && let hir::ItemKind::Impl(impl_) = item.kind && let Some(of_trait) = impl_.of_trait && let Some(def_id) = of_trait.trait_ref.trait_def_id() && self.tcx.is_lang_item(def_id, hir::LangItem::Drop) { return; } self.dcx().emit_err(errors::InvalidMayDangle { attr_span }); } /// Checks if `#[link]` is applied to an item other than a foreign module. fn check_link(&self, hir_id: HirId, attr_span: Span, span: Span, target: Target) { if target == Target::ForeignMod && let hir::Node::Item(item) = self.tcx.hir_node(hir_id) && let Item { kind: ItemKind::ForeignMod { abi, .. }, .. } = item && !matches!(abi, ExternAbi::Rust) { return; } self.tcx.emit_node_span_lint( UNUSED_ATTRIBUTES, hir_id, attr_span, errors::Link { span: (target != Target::ForeignMod).then_some(span) }, ); } /// Checks if `#[no_link]` is applied to an `extern crate`. fn check_no_link(&self, hir_id: HirId, attr: &Attribute, span: Span, target: Target) { match target { Target::ExternCrate => {} // FIXME(#80564): We permit struct fields, match arms and macro defs to have an // `#[no_link]` attribute with just a lint, because we previously // erroneously allowed it and some crates used it accidentally, to be compatible // with crates depending on them, we can't throw an error here. Target::Field | Target::Arm | Target::MacroDef => { self.inline_attr_str_error_with_macro_def(hir_id, attr.span(), "no_link"); } _ => { self.dcx().emit_err(errors::NoLink { attr_span: attr.span(), span }); } } } /// Checks if `#[rustc_legacy_const_generics]` is applied to a function and has a valid argument. fn check_rustc_legacy_const_generics( &self, hir_id: HirId, attr: &Attribute, span: Span, target: Target, item: Option>, ) { let is_function = matches!(target, Target::Fn); if !is_function { self.dcx().emit_err(errors::AttrShouldBeAppliedToFn { attr_span: attr.span(), defn_span: span, on_crate: hir_id == CRATE_HIR_ID, }); return; } let Some(list) = attr.meta_item_list() else { // The attribute form is validated on AST. return; }; let Some(ItemLike::Item(Item { kind: ItemKind::Fn { sig: FnSig { decl, .. }, generics, .. }, .. })) = item else { bug!("should be a function item"); }; for param in generics.params { match param.kind { hir::GenericParamKind::Const { .. } => {} _ => { self.dcx().emit_err(errors::RustcLegacyConstGenericsOnly { attr_span: attr.span(), param_span: param.span, }); return; } } } if list.len() != generics.params.len() { self.dcx().emit_err(errors::RustcLegacyConstGenericsIndex { attr_span: attr.span(), generics_span: generics.span, }); return; } let arg_count = decl.inputs.len() as u128 + generics.params.len() as u128; let mut invalid_args = vec![]; for meta in list { if let Some(LitKind::Int(val, _)) = meta.lit().map(|lit| &lit.kind) { if *val >= arg_count { let span = meta.span(); self.dcx().emit_err(errors::RustcLegacyConstGenericsIndexExceed { span, arg_count: arg_count as usize, }); return; } } else { invalid_args.push(meta.span()); } } if !invalid_args.is_empty() { self.dcx().emit_err(errors::RustcLegacyConstGenericsIndexNegative { invalid_args }); } } /// Helper function for checking that the provided attribute is only applied to a function or /// method. fn check_applied_to_fn_or_method( &self, hir_id: HirId, attr_span: Span, defn_span: Span, target: Target, ) { let is_function = matches!(target, Target::Fn | Target::Method(..)); if !is_function { self.dcx().emit_err(errors::AttrShouldBeAppliedToFn { attr_span, defn_span, on_crate: hir_id == CRATE_HIR_ID, }); } } /// Checks that the `#[rustc_lint_opt_ty]` attribute is only applied to a struct. fn check_rustc_lint_opt_ty(&self, attr: &Attribute, span: Span, target: Target) { match target { Target::Struct => {} _ => { self.dcx().emit_err(errors::RustcLintOptTy { attr_span: attr.span(), span }); } } } /// Checks that the `#[rustc_lint_opt_deny_field_access]` attribute is only applied to a field. fn check_rustc_lint_opt_deny_field_access(&self, attr: &Attribute, span: Span, target: Target) { match target { Target::Field => {} _ => { self.tcx .dcx() .emit_err(errors::RustcLintOptDenyFieldAccess { attr_span: attr.span(), span }); } } } /// Checks that the dep-graph debugging attributes are only present when the query-dep-graph /// option is passed to the compiler. fn check_rustc_dirty_clean(&self, attr: &Attribute) { if !self.tcx.sess.opts.unstable_opts.query_dep_graph { self.dcx().emit_err(errors::RustcDirtyClean { span: attr.span() }); } } /// Checks if the attribute is applied to a trait. fn check_must_be_applied_to_trait(&self, attr_span: Span, defn_span: Span, target: Target) { match target { Target::Trait => {} _ => { self.dcx().emit_err(errors::AttrShouldBeAppliedToTrait { attr_span, defn_span }); } } } /// Checks if the `#[repr]` attributes on `item` are valid. fn check_repr( &self, attrs: &[Attribute], span: Span, target: Target, item: Option>, hir_id: HirId, ) { // Extract the names of all repr hints, e.g., [foo, bar, align] for: // ``` // #[repr(foo)] // #[repr(bar, align(8))] // ``` let (reprs, first_attr_span) = find_attr!(attrs, AttributeKind::Repr { reprs, first_span } => (reprs.as_slice(), Some(*first_span))).unwrap_or((&[], None)); let mut int_reprs = 0; let mut is_explicit_rust = false; let mut is_c = false; let mut is_simd = false; let mut is_transparent = false; for (repr, repr_span) in reprs { match repr { ReprAttr::ReprRust => { is_explicit_rust = true; match target { Target::Struct | Target::Union | Target::Enum => continue, _ => { self.dcx().emit_err(errors::AttrApplication::StructEnumUnion { hint_span: *repr_span, span, }); } } } ReprAttr::ReprC => { is_c = true; match target { Target::Struct | Target::Union | Target::Enum => continue, _ => { self.dcx().emit_err(errors::AttrApplication::StructEnumUnion { hint_span: *repr_span, span, }); } } } ReprAttr::ReprAlign(align) => { match target { Target::Struct | Target::Union | Target::Enum => {} Target::Fn | Target::Method(_) if self.tcx.features().fn_align() => { self.dcx().emit_err(errors::ReprAlignShouldBeAlign { span: *repr_span, item: target.plural_name(), }); } Target::Static if self.tcx.features().static_align() => { self.dcx().emit_err(errors::ReprAlignShouldBeAlignStatic { span: *repr_span, item: target.plural_name(), }); } _ => { self.dcx().emit_err(errors::AttrApplication::StructEnumUnion { hint_span: *repr_span, span, }); } } self.check_align(*align, *repr_span); } ReprAttr::ReprPacked(_) => { if target != Target::Struct && target != Target::Union { self.dcx().emit_err(errors::AttrApplication::StructUnion { hint_span: *repr_span, span, }); } else { continue; } } ReprAttr::ReprSimd => { is_simd = true; if target != Target::Struct { self.dcx().emit_err(errors::AttrApplication::Struct { hint_span: *repr_span, span, }); } else { continue; } } ReprAttr::ReprTransparent => { is_transparent = true; match target { Target::Struct | Target::Union | Target::Enum => continue, _ => { self.dcx().emit_err(errors::AttrApplication::StructEnumUnion { hint_span: *repr_span, span, }); } } } ReprAttr::ReprInt(_) => { int_reprs += 1; if target != Target::Enum { self.dcx().emit_err(errors::AttrApplication::Enum { hint_span: *repr_span, span, }); } else { continue; } } }; } // catch `repr()` with no arguments, applied to an item (i.e. not `#![repr()]`) if let Some(first_attr_span) = first_attr_span && reprs.is_empty() && item.is_some() { match target { Target::Struct | Target::Union | Target::Enum => {} Target::Fn | Target::Method(_) => { self.dcx().emit_err(errors::ReprAlignShouldBeAlign { span: first_attr_span, item: target.plural_name(), }); } _ => { self.dcx().emit_err(errors::AttrApplication::StructEnumUnion { hint_span: first_attr_span, span, }); } } return; } // Just point at all repr hints if there are any incompatibilities. // This is not ideal, but tracking precisely which ones are at fault is a huge hassle. let hint_spans = reprs.iter().map(|(_, span)| *span); // Error on repr(transparent, ). if is_transparent && reprs.len() > 1 { let hint_spans = hint_spans.clone().collect(); self.dcx().emit_err(errors::TransparentIncompatible { hint_spans, target: target.to_string(), }); } if is_explicit_rust && (int_reprs > 0 || is_c || is_simd) { let hint_spans = hint_spans.clone().collect(); self.dcx().emit_err(errors::ReprConflicting { hint_spans }); } // Warn on repr(u8, u16), repr(C, simd), and c-like-enum-repr(C, u8) if (int_reprs > 1) || (is_simd && is_c) || (int_reprs == 1 && is_c && item.is_some_and(|item| { if let ItemLike::Item(item) = item { is_c_like_enum(item) } else { false } })) { self.tcx.emit_node_span_lint( CONFLICTING_REPR_HINTS, hir_id, hint_spans.collect::>(), errors::ReprConflictingLint, ); } } fn check_align(&self, align: Align, span: Span) { if align.bytes() > 2_u64.pow(29) { // for values greater than 2^29, a different error will be emitted, make sure that happens self.dcx().span_delayed_bug( span, "alignment greater than 2^29 should be errored on elsewhere", ); } else { // only do this check when <= 2^29 to prevent duplicate errors: // alignment greater than 2^29 not supported // alignment is too large for the current target let max = Size::from_bits(self.tcx.sess.target.pointer_width).signed_int_max() as u64; if align.bytes() > max { self.dcx().emit_err(errors::InvalidReprAlignForTarget { span, size: max }); } } } /// Outputs an error for attributes that can only be applied to macros, such as /// `#[allow_internal_unsafe]` and `#[allow_internal_unstable]`. /// (Allows proc_macro functions) // FIXME(jdonszelmann): if possible, move to attr parsing fn check_macro_only_attr( &self, attr_span: Span, span: Span, target: Target, attrs: &[Attribute], ) { match target { Target::Fn => { for attr in attrs { if attr.is_proc_macro_attr() { // return on proc macros return; } } self.tcx.dcx().emit_err(errors::MacroOnlyAttribute { attr_span, span }); } _ => {} } } /// Checks if the items on the `#[debugger_visualizer]` attribute are valid. fn check_debugger_visualizer(&self, attr: &Attribute, target: Target) { // Here we only check that the #[debugger_visualizer] attribute is attached // to nothing other than a module. All other checks are done in the // `debugger_visualizer` query where they need to be done for decoding // anyway. match target { Target::Mod => {} _ => { self.dcx().emit_err(errors::DebugVisualizerPlacement { span: attr.span() }); } } } /// Outputs an error for `#[allow_internal_unstable]` which can only be applied to macros. /// (Allows proc_macro functions) fn check_rustc_allow_const_fn_unstable( &self, hir_id: HirId, attr_span: Span, span: Span, target: Target, ) { match target { Target::Fn | Target::Method(_) => { if !self.tcx.is_const_fn(hir_id.expect_owner().to_def_id()) { self.tcx.dcx().emit_err(errors::RustcAllowConstFnUnstable { attr_span, span }); } } _ => {} } } fn check_stability( &self, attr_span: Span, item_span: Span, level: &StabilityLevel, feature: Symbol, ) { // Stable *language* features shouldn't be used as unstable library features. // (Not doing this for stable library features is checked by tidy.) if level.is_unstable() && ACCEPTED_LANG_FEATURES.iter().find(|f| f.name == feature).is_some() { self.tcx .dcx() .emit_err(errors::UnstableAttrForAlreadyStableFeature { attr_span, item_span }); } } fn check_deprecated(&self, hir_id: HirId, attr: &Attribute, _span: Span, target: Target) { match target { Target::AssocConst | Target::Method(..) | Target::AssocTy if matches!( self.tcx.def_kind(self.tcx.local_parent(hir_id.owner.def_id)), DefKind::Impl { of_trait: true } ) => { self.tcx.emit_node_span_lint( UNUSED_ATTRIBUTES, hir_id, attr.span(), errors::DeprecatedAnnotationHasNoEffect { span: attr.span() }, ); } _ => {} } } fn check_macro_export(&self, hir_id: HirId, attr: &Attribute, target: Target) { if target != Target::MacroDef { self.tcx.emit_node_span_lint( UNUSED_ATTRIBUTES, hir_id, attr.span(), errors::MacroExport::Normal, ); } else if let Some(meta_item_list) = attr.meta_item_list() && !meta_item_list.is_empty() { if meta_item_list.len() > 1 { self.tcx.emit_node_span_lint( INVALID_MACRO_EXPORT_ARGUMENTS, hir_id, attr.span(), errors::MacroExport::TooManyItems, ); } else if !meta_item_list[0].has_name(sym::local_inner_macros) { self.tcx.emit_node_span_lint( INVALID_MACRO_EXPORT_ARGUMENTS, hir_id, meta_item_list[0].span(), errors::MacroExport::InvalidArgument, ); } } else { // special case when `#[macro_export]` is applied to a macro 2.0 let (_, macro_definition, _) = self.tcx.hir_node(hir_id).expect_item().expect_macro(); let is_decl_macro = !macro_definition.macro_rules; if is_decl_macro { self.tcx.emit_node_span_lint( UNUSED_ATTRIBUTES, hir_id, attr.span(), errors::MacroExport::OnDeclMacro, ); } } } fn check_unused_attribute(&self, hir_id: HirId, attr: &Attribute, style: Option) { // Warn on useless empty attributes. // FIXME(jdonszelmann): this lint should be moved to attribute parsing, see `AcceptContext::warn_empty_attribute` let note = if attr.has_any_name(&[ sym::allow, sym::expect, sym::warn, sym::deny, sym::forbid, sym::feature, ]) && attr.meta_item_list().is_some_and(|list| list.is_empty()) { errors::UnusedNote::EmptyList { name: attr.name().unwrap() } } else if attr.has_any_name(&[sym::allow, sym::warn, sym::deny, sym::forbid, sym::expect]) && let Some(meta) = attr.meta_item_list() && let [meta] = meta.as_slice() && let Some(item) = meta.meta_item() && let MetaItemKind::NameValue(_) = &item.kind && item.path == sym::reason { errors::UnusedNote::NoLints { name: attr.name().unwrap() } } else if attr.has_any_name(&[sym::allow, sym::warn, sym::deny, sym::forbid, sym::expect]) && let Some(meta) = attr.meta_item_list() && meta.iter().any(|meta| { meta.meta_item().map_or(false, |item| item.path == sym::linker_messages) }) { if hir_id != CRATE_HIR_ID { match style { Some(ast::AttrStyle::Outer) => { let attr_span = attr.span(); let bang_position = self .tcx .sess .source_map() .span_until_char(attr_span, '[') .shrink_to_hi(); self.tcx.emit_node_span_lint( UNUSED_ATTRIBUTES, hir_id, attr_span, errors::OuterCrateLevelAttr { suggestion: errors::OuterCrateLevelAttrSuggestion { bang_position }, }, ) } Some(ast::AttrStyle::Inner) | None => self.tcx.emit_node_span_lint( UNUSED_ATTRIBUTES, hir_id, attr.span(), errors::InnerCrateLevelAttr, ), }; return; } else { let never_needs_link = self .tcx .crate_types() .iter() .all(|kind| matches!(kind, CrateType::Rlib | CrateType::Staticlib)); if never_needs_link { errors::UnusedNote::LinkerMessagesBinaryCrateOnly } else { return; } } } else if attr.has_name(sym::default_method_body_is_const) { errors::UnusedNote::DefaultMethodBodyConst } else { return; }; self.tcx.emit_node_span_lint( UNUSED_ATTRIBUTES, hir_id, attr.span(), errors::Unused { attr_span: attr.span(), note }, ); } /// A best effort attempt to create an error for a mismatching proc macro signature. /// /// If this best effort goes wrong, it will just emit a worse error later (see #102923) fn check_proc_macro(&self, hir_id: HirId, target: Target, kind: ProcMacroKind) { if target != Target::Fn { return; } let tcx = self.tcx; let Some(token_stream_def_id) = tcx.get_diagnostic_item(sym::TokenStream) else { return; }; let Some(token_stream) = tcx.type_of(token_stream_def_id).no_bound_vars() else { return; }; let def_id = hir_id.expect_owner().def_id; let param_env = ty::ParamEnv::empty(); let infcx = tcx.infer_ctxt().build(TypingMode::non_body_analysis()); let ocx = ObligationCtxt::new_with_diagnostics(&infcx); let span = tcx.def_span(def_id); let fresh_args = infcx.fresh_args_for_item(span, def_id.to_def_id()); let sig = tcx.liberate_late_bound_regions( def_id.to_def_id(), tcx.fn_sig(def_id).instantiate(tcx, fresh_args), ); let mut cause = ObligationCause::misc(span, def_id); let sig = ocx.normalize(&cause, param_env, sig); // proc macro is not WF. let errors = ocx.select_where_possible(); if !errors.is_empty() { return; } let expected_sig = tcx.mk_fn_sig( std::iter::repeat(token_stream).take(match kind { ProcMacroKind::Attribute => 2, ProcMacroKind::Derive | ProcMacroKind::FunctionLike => 1, }), token_stream, false, Safety::Safe, ExternAbi::Rust, ); if let Err(terr) = ocx.eq(&cause, param_env, expected_sig, sig) { let mut diag = tcx.dcx().create_err(errors::ProcMacroBadSig { span, kind }); let hir_sig = tcx.hir_fn_sig_by_hir_id(hir_id); if let Some(hir_sig) = hir_sig { #[allow(rustc::diagnostic_outside_of_impl)] // FIXME match terr { TypeError::ArgumentMutability(idx) | TypeError::ArgumentSorts(_, idx) => { if let Some(ty) = hir_sig.decl.inputs.get(idx) { diag.span(ty.span); cause.span = ty.span; } else if idx == hir_sig.decl.inputs.len() { let span = hir_sig.decl.output.span(); diag.span(span); cause.span = span; } } TypeError::ArgCount => { if let Some(ty) = hir_sig.decl.inputs.get(expected_sig.inputs().len()) { diag.span(ty.span); cause.span = ty.span; } } TypeError::SafetyMismatch(_) => { // FIXME: Would be nice if we had a span here.. } TypeError::AbiMismatch(_) => { // FIXME: Would be nice if we had a span here.. } TypeError::VariadicMismatch(_) => { // FIXME: Would be nice if we had a span here.. } _ => {} } } infcx.err_ctxt().note_type_err( &mut diag, &cause, None, Some(param_env.and(ValuePairs::PolySigs(ExpectedFound { expected: ty::Binder::dummy(expected_sig), found: ty::Binder::dummy(sig), }))), terr, false, None, ); diag.emit(); self.abort.set(true); } let errors = ocx.select_all_or_error(); if !errors.is_empty() { infcx.err_ctxt().report_fulfillment_errors(errors); self.abort.set(true); } } fn check_type_const(&self, hir_id: HirId, attr_span: Span, target: Target) { let tcx = self.tcx; if target == Target::AssocConst && let parent = tcx.parent(hir_id.expect_owner().to_def_id()) && self.tcx.def_kind(parent) == DefKind::Trait { return; } else { self.dcx() .struct_span_err( attr_span, "`#[type_const]` must only be applied to trait associated constants", ) .emit(); } } fn check_rustc_pub_transparent(&self, attr_span: Span, span: Span, attrs: &[Attribute]) { if !find_attr!(attrs, AttributeKind::Repr { reprs, .. } => reprs.iter().any(|(r, _)| r == &ReprAttr::ReprTransparent)) .unwrap_or(false) { self.dcx().emit_err(errors::RustcPubTransparent { span, attr_span }); } } fn check_rustc_force_inline(&self, hir_id: HirId, attrs: &[Attribute], target: Target) { if let (Target::Closure, None) = ( target, find_attr!(attrs, AttributeKind::Inline(InlineAttr::Force { attr_span, .. }, _) => *attr_span), ) { let is_coro = matches!( self.tcx.hir_expect_expr(hir_id).kind, hir::ExprKind::Closure(hir::Closure { kind: hir::ClosureKind::Coroutine(..) | hir::ClosureKind::CoroutineClosure(..), .. }) ); let parent_did = self.tcx.hir_get_parent_item(hir_id).to_def_id(); let parent_span = self.tcx.def_span(parent_did); if let Some(attr_span) = find_attr!( self.tcx.get_all_attrs(parent_did), AttributeKind::Inline(InlineAttr::Force { attr_span, .. }, _) => *attr_span ) && is_coro { self.dcx().emit_err(errors::RustcForceInlineCoro { attr_span, span: parent_span }); } } } fn check_mix_no_mangle_export(&self, hir_id: HirId, attrs: &[Attribute]) { if let Some(export_name_span) = find_attr!(attrs, AttributeKind::ExportName { span: export_name_span, .. } => *export_name_span) && let Some(no_mangle_span) = find_attr!(attrs, AttributeKind::NoMangle(no_mangle_span) => *no_mangle_span) { let no_mangle_attr = if no_mangle_span.edition() >= Edition::Edition2024 { "#[unsafe(no_mangle)]" } else { "#[no_mangle]" }; let export_name_attr = if export_name_span.edition() >= Edition::Edition2024 { "#[unsafe(export_name)]" } else { "#[export_name]" }; self.tcx.emit_node_span_lint( lint::builtin::UNUSED_ATTRIBUTES, hir_id, no_mangle_span, errors::MixedExportNameAndNoMangle { no_mangle_span, export_name_span, no_mangle_attr, export_name_attr, }, ); } } /// Checks if `#[autodiff]` is applied to an item other than a function item. fn check_autodiff(&self, _hir_id: HirId, _attr: &Attribute, span: Span, target: Target) { debug!("check_autodiff"); match target { Target::Fn => {} _ => { self.dcx().emit_err(errors::AutoDiffAttr { attr_span: span }); self.abort.set(true); } } } fn check_loop_match(&self, hir_id: HirId, attr_span: Span, target: Target) { let node_span = self.tcx.hir_span(hir_id); if !matches!(target, Target::Expression) { return; // Handled in target checking during attr parse } if !matches!(self.tcx.hir_expect_expr(hir_id).kind, hir::ExprKind::Loop(..)) { self.dcx().emit_err(errors::LoopMatchAttr { attr_span, node_span }); }; } fn check_const_continue(&self, hir_id: HirId, attr_span: Span, target: Target) { let node_span = self.tcx.hir_span(hir_id); if !matches!(target, Target::Expression) { return; // Handled in target checking during attr parse } if !matches!(self.tcx.hir_expect_expr(hir_id).kind, hir::ExprKind::Break(..)) { self.dcx().emit_err(errors::ConstContinueAttr { attr_span, node_span }); }; } fn check_custom_mir( &self, dialect: Option<(MirDialect, Span)>, phase: Option<(MirPhase, Span)>, attr_span: Span, ) { let Some((dialect, dialect_span)) = dialect else { if let Some((_, phase_span)) = phase { self.dcx() .emit_err(errors::CustomMirPhaseRequiresDialect { attr_span, phase_span }); } return; }; match dialect { MirDialect::Analysis => { if let Some((MirPhase::Optimized, phase_span)) = phase { self.dcx().emit_err(errors::CustomMirIncompatibleDialectAndPhase { dialect, phase: MirPhase::Optimized, attr_span, dialect_span, phase_span, }); } } MirDialect::Built => { if let Some((phase, phase_span)) = phase { self.dcx().emit_err(errors::CustomMirIncompatibleDialectAndPhase { dialect, phase, attr_span, dialect_span, phase_span, }); } } MirDialect::Runtime => {} } } } impl<'tcx> Visitor<'tcx> for CheckAttrVisitor<'tcx> { type NestedFilter = nested_filter::OnlyBodies; fn maybe_tcx(&mut self) -> Self::MaybeTyCtxt { self.tcx } fn visit_item(&mut self, item: &'tcx Item<'tcx>) { // Historically we've run more checks on non-exported than exported macros, // so this lets us continue to run them while maintaining backwards compatibility. // In the long run, the checks should be harmonized. if let ItemKind::Macro(_, macro_def, _) = item.kind { let def_id = item.owner_id.to_def_id(); if macro_def.macro_rules && !self.tcx.has_attr(def_id, sym::macro_export) { check_non_exported_macro_for_invalid_attrs(self.tcx, item); } } let target = Target::from_item(item); self.check_attributes(item.hir_id(), item.span, target, Some(ItemLike::Item(item))); intravisit::walk_item(self, item) } fn visit_where_predicate(&mut self, where_predicate: &'tcx hir::WherePredicate<'tcx>) { // FIXME(where_clause_attrs): Currently, as the following check shows, // only `#[cfg]` and `#[cfg_attr]` are allowed, but it should be removed // if we allow more attributes (e.g., tool attributes and `allow/deny/warn`) // in where clauses. After that, only `self.check_attributes` should be enough. const ATTRS_ALLOWED: &[Symbol] = &[sym::cfg_trace, sym::cfg_attr_trace]; let spans = self .tcx .hir_attrs(where_predicate.hir_id) .iter() .filter(|attr| !ATTRS_ALLOWED.iter().any(|&sym| attr.has_name(sym))) .filter(|attr| !attr.is_parsed_attr()) .map(|attr| attr.span()) .collect::>(); if !spans.is_empty() { self.tcx.dcx().emit_err(errors::UnsupportedAttributesInWhere { span: spans.into() }); } self.check_attributes( where_predicate.hir_id, where_predicate.span, Target::WherePredicate, None, ); intravisit::walk_where_predicate(self, where_predicate) } fn visit_generic_param(&mut self, generic_param: &'tcx hir::GenericParam<'tcx>) { let target = Target::from_generic_param(generic_param); self.check_attributes(generic_param.hir_id, generic_param.span, target, None); intravisit::walk_generic_param(self, generic_param) } fn visit_trait_item(&mut self, trait_item: &'tcx TraitItem<'tcx>) { let target = Target::from_trait_item(trait_item); self.check_attributes(trait_item.hir_id(), trait_item.span, target, None); intravisit::walk_trait_item(self, trait_item) } fn visit_field_def(&mut self, struct_field: &'tcx hir::FieldDef<'tcx>) { self.check_attributes(struct_field.hir_id, struct_field.span, Target::Field, None); intravisit::walk_field_def(self, struct_field); } fn visit_arm(&mut self, arm: &'tcx hir::Arm<'tcx>) { self.check_attributes(arm.hir_id, arm.span, Target::Arm, None); intravisit::walk_arm(self, arm); } fn visit_foreign_item(&mut self, f_item: &'tcx ForeignItem<'tcx>) { let target = Target::from_foreign_item(f_item); self.check_attributes(f_item.hir_id(), f_item.span, target, Some(ItemLike::ForeignItem)); intravisit::walk_foreign_item(self, f_item) } fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem<'tcx>) { let target = target_from_impl_item(self.tcx, impl_item); self.check_attributes(impl_item.hir_id(), impl_item.span, target, None); intravisit::walk_impl_item(self, impl_item) } fn visit_stmt(&mut self, stmt: &'tcx hir::Stmt<'tcx>) { // When checking statements ignore expressions, they will be checked later. if let hir::StmtKind::Let(l) = stmt.kind { self.check_attributes(l.hir_id, stmt.span, Target::Statement, None); } intravisit::walk_stmt(self, stmt) } fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) { let target = match expr.kind { hir::ExprKind::Closure { .. } => Target::Closure, _ => Target::Expression, }; self.check_attributes(expr.hir_id, expr.span, target, None); intravisit::walk_expr(self, expr) } fn visit_expr_field(&mut self, field: &'tcx hir::ExprField<'tcx>) { self.check_attributes(field.hir_id, field.span, Target::ExprField, None); intravisit::walk_expr_field(self, field) } fn visit_variant(&mut self, variant: &'tcx hir::Variant<'tcx>) { self.check_attributes(variant.hir_id, variant.span, Target::Variant, None); intravisit::walk_variant(self, variant) } fn visit_param(&mut self, param: &'tcx hir::Param<'tcx>) { self.check_attributes(param.hir_id, param.span, Target::Param, None); intravisit::walk_param(self, param); } fn visit_pat_field(&mut self, field: &'tcx hir::PatField<'tcx>) { self.check_attributes(field.hir_id, field.span, Target::PatField, None); intravisit::walk_pat_field(self, field); } } fn is_c_like_enum(item: &Item<'_>) -> bool { if let ItemKind::Enum(_, _, ref def) = item.kind { for variant in def.variants { match variant.data { hir::VariantData::Unit(..) => { /* continue */ } _ => return false, } } true } else { false } } // FIXME: Fix "Cannot determine resolution" error and remove built-in macros // from this check. fn check_invalid_crate_level_attr(tcx: TyCtxt<'_>, attrs: &[Attribute]) { // Check for builtin attributes at the crate level // which were unsuccessfully resolved due to cannot determine // resolution for the attribute macro error. const ATTRS_TO_CHECK: &[Symbol] = &[ sym::macro_export, sym::rustc_main, sym::derive, sym::test, sym::test_case, sym::global_allocator, sym::bench, ]; for attr in attrs { // FIXME(jdonszelmann): all attrs should be combined here cleaning this up some day. let (span, name) = if let Some(a) = ATTRS_TO_CHECK.iter().find(|attr_to_check| attr.has_name(**attr_to_check)) { (attr.span(), *a) } else if let Attribute::Parsed(AttributeKind::Repr { reprs: _, first_span: first_attr_span, }) = attr { (*first_attr_span, sym::repr) } else { continue; }; let item = tcx .hir_free_items() .map(|id| tcx.hir_item(id)) .find(|item| !item.span.is_dummy()) // Skip prelude `use`s .map(|item| errors::ItemFollowingInnerAttr { span: if let Some(ident) = item.kind.ident() { ident.span } else { item.span }, kind: tcx.def_descr(item.owner_id.to_def_id()), }); let err = tcx.dcx().create_err(errors::InvalidAttrAtCrateLevel { span, sugg_span: tcx .sess .source_map() .span_to_snippet(span) .ok() .filter(|src| src.starts_with("#![")) .map(|_| span.with_lo(span.lo() + BytePos(1)).with_hi(span.lo() + BytePos(2))), name, item, }); if let Attribute::Unparsed(p) = attr { tcx.dcx().try_steal_replace_and_emit_err( p.path.span, StashKey::UndeterminedMacroResolution, err, ); } else { err.emit(); } } } fn check_non_exported_macro_for_invalid_attrs(tcx: TyCtxt<'_>, item: &Item<'_>) { let attrs = tcx.hir_attrs(item.hir_id()); if let Some(attr_span) = find_attr!(attrs, AttributeKind::Inline(i, span) if !matches!(i, InlineAttr::Force{..}) => *span) { tcx.dcx().emit_err(errors::NonExportedMacroInvalidAttrs { attr_span }); } } fn check_mod_attrs(tcx: TyCtxt<'_>, module_def_id: LocalModDefId) { let check_attr_visitor = &mut CheckAttrVisitor { tcx, abort: Cell::new(false) }; tcx.hir_visit_item_likes_in_module(module_def_id, check_attr_visitor); if module_def_id.to_local_def_id().is_top_level_module() { check_attr_visitor.check_attributes(CRATE_HIR_ID, DUMMY_SP, Target::Mod, None); check_invalid_crate_level_attr(tcx, tcx.hir_krate_attrs()); } if check_attr_visitor.abort.get() { tcx.dcx().abort_if_errors() } } pub(crate) fn provide(providers: &mut Providers) { *providers = Providers { check_mod_attrs, ..*providers }; } // FIXME(jdonszelmann): remove, check during parsing fn check_duplicates( tcx: TyCtxt<'_>, attr: &Attribute, hir_id: HirId, duplicates: AttributeDuplicates, seen: &mut FxHashMap, ) { use AttributeDuplicates::*; if matches!(duplicates, WarnFollowingWordOnly) && !attr.is_word() { return; } let attr_name = attr.name().unwrap(); match duplicates { DuplicatesOk => {} WarnFollowing | FutureWarnFollowing | WarnFollowingWordOnly | FutureWarnPreceding => { match seen.entry(attr_name) { Entry::Occupied(mut entry) => { let (this, other) = if matches!(duplicates, FutureWarnPreceding) { let to_remove = entry.insert(attr.span()); (to_remove, attr.span()) } else { (attr.span(), *entry.get()) }; tcx.emit_node_span_lint( UNUSED_ATTRIBUTES, hir_id, this, errors::UnusedDuplicate { this, other, warning: matches!( duplicates, FutureWarnFollowing | FutureWarnPreceding ), }, ); } Entry::Vacant(entry) => { entry.insert(attr.span()); } } } ErrorFollowing | ErrorPreceding => match seen.entry(attr_name) { Entry::Occupied(mut entry) => { let (this, other) = if matches!(duplicates, ErrorPreceding) { let to_remove = entry.insert(attr.span()); (to_remove, attr.span()) } else { (attr.span(), *entry.get()) }; tcx.dcx().emit_err(errors::UnusedMultiple { this, other, name: attr_name }); } Entry::Vacant(entry) => { entry.insert(attr.span()); } }, } } fn doc_fake_variadic_is_allowed_self_ty(self_ty: &hir::Ty<'_>) -> bool { matches!(&self_ty.kind, hir::TyKind::Tup([_])) || if let hir::TyKind::FnPtr(fn_ptr_ty) = &self_ty.kind { fn_ptr_ty.decl.inputs.len() == 1 } else { false } || (if let hir::TyKind::Path(hir::QPath::Resolved(_, path)) = &self_ty.kind && let Some(&[hir::GenericArg::Type(ty)]) = path.segments.last().map(|last| last.args().args) { doc_fake_variadic_is_allowed_self_ty(ty.as_unambig_ty()) } else { false }) }