| //! 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 rustc_ast::{ |
| ast, AttrKind, AttrStyle, Attribute, LitKind, MetaItemKind, MetaItemLit, NestedMetaItem, |
| }; |
| use rustc_data_structures::fx::FxHashMap; |
| use rustc_errors::{Applicability, DiagCtxtHandle, IntoDiagArg, MultiSpan, StashKey}; |
| use rustc_feature::{AttributeDuplicates, AttributeType, BuiltinAttribute, BUILTIN_ATTRIBUTE_MAP}; |
| use rustc_hir::def_id::LocalModDefId; |
| use rustc_hir::intravisit::{self, Visitor}; |
| use rustc_hir::{ |
| self as hir, self, FnSig, ForeignItem, HirId, Item, ItemKind, MethodKind, Safety, Target, |
| TraitItem, CRATE_HIR_ID, CRATE_OWNER_ID, |
| }; |
| 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}; |
| use rustc_middle::{bug, span_bug}; |
| use rustc_session::lint::builtin::{ |
| CONFLICTING_REPR_HINTS, INVALID_DOC_ATTRIBUTES, INVALID_MACRO_EXPORT_ARGUMENTS, |
| UNKNOWN_OR_MALFORMED_DIAGNOSTIC_ATTRIBUTES, UNUSED_ATTRIBUTES, |
| }; |
| use rustc_session::parse::feature_err; |
| use rustc_span::symbol::{kw, sym, Symbol}; |
| use rustc_span::{BytePos, Span, DUMMY_SP}; |
| use rustc_target::spec::abi::Abi; |
| 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) -> rustc_errors::DiagArgValue { |
| match self { |
| ProcMacroKind::Attribute => "attribute proc macro", |
| ProcMacroKind::Derive => "derive proc macro", |
| ProcMacroKind::FunctionLike => "function-like proc macro", |
| } |
| .into_diag_arg() |
| } |
| } |
| |
| struct CheckAttrVisitor<'tcx> { |
| tcx: TyCtxt<'tcx>, |
| |
| // Whether or not this visitor should abort after finding errors |
| abort: Cell<bool>, |
| } |
| |
| 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<ItemLike<'_>>, |
| ) { |
| 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 { |
| match attr.path().as_slice() { |
| [sym::diagnostic, sym::do_not_recommend, ..] => { |
| self.check_do_not_recommend(attr.span, hir_id, target) |
| } |
| [sym::diagnostic, sym::on_unimplemented, ..] => { |
| self.check_diagnostic_on_unimplemented(attr.span, hir_id, target) |
| } |
| [sym::inline, ..] => self.check_inline(hir_id, attr, span, target), |
| [sym::coverage, ..] => self.check_coverage(attr, span, target), |
| [sym::optimize, ..] => self.check_optimize(hir_id, attr, target), |
| [sym::no_sanitize, ..] => self.check_no_sanitize(hir_id, attr, span, target), |
| [sym::non_exhaustive, ..] => self.check_non_exhaustive(hir_id, attr, span, target), |
| [sym::marker, ..] => self.check_marker(hir_id, attr, span, target), |
| [sym::target_feature, ..] => { |
| self.check_target_feature(hir_id, attr, span, target, attrs) |
| } |
| [sym::thread_local, ..] => self.check_thread_local(attr, span, target), |
| [sym::track_caller, ..] => { |
| self.check_track_caller(hir_id, attr.span, attrs, span, target) |
| } |
| [sym::doc, ..] => self.check_doc_attrs( |
| attr, |
| hir_id, |
| target, |
| &mut specified_inline, |
| &mut doc_aliases, |
| ), |
| [sym::no_link, ..] => self.check_no_link(hir_id, attr, span, target), |
| [sym::export_name, ..] => self.check_export_name(hir_id, attr, span, target), |
| [sym::rustc_layout_scalar_valid_range_start, ..] |
| | [sym::rustc_layout_scalar_valid_range_end, ..] => { |
| self.check_rustc_layout_scalar_valid_range(attr, span, target) |
| } |
| [sym::allow_internal_unstable, ..] => { |
| self.check_allow_internal_unstable(hir_id, attr, span, target, attrs) |
| } |
| [sym::debugger_visualizer, ..] => self.check_debugger_visualizer(attr, target), |
| [sym::rustc_allow_const_fn_unstable, ..] => { |
| self.check_rustc_allow_const_fn_unstable(hir_id, attr, span, target) |
| } |
| [sym::rustc_std_internal_symbol, ..] => { |
| self.check_rustc_std_internal_symbol(attr, span, target) |
| } |
| [sym::naked, ..] => self.check_naked(hir_id, attr, span, target, attrs), |
| [sym::rustc_never_returns_null_ptr, ..] => { |
| self.check_applied_to_fn_or_method(hir_id, attr, 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_rustc_lint_query_instability(hir_id, attr, span, target) |
| } |
| [sym::rustc_lint_diagnostics, ..] => { |
| self.check_rustc_lint_diagnostics(hir_id, attr, 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_coinductive, ..] |
| | [sym::rustc_must_implement_one_of, ..] |
| | [sym::rustc_deny_explicit_impl, ..] |
| | [sym::const_trait, ..] => self.check_must_be_applied_to_trait(attr, span, target), |
| [sym::cmse_nonsecure_entry, ..] => { |
| self.check_cmse_nonsecure_entry(hir_id, attr, 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::must_use, ..] => self.check_must_use(hir_id, attr, target), |
| [sym::may_dangle, ..] => self.check_may_dangle(hir_id, attr), |
| [sym::rustc_pass_by_value, ..] => self.check_pass_by_value(attr, span, target), |
| [sym::rustc_allow_incoherent_impl, ..] => { |
| self.check_allow_incoherent_impl(attr, span, target) |
| } |
| [sym::rustc_has_incoherent_inherent_impls, ..] => { |
| self.check_has_incoherent_inherent_impls(attr, span, target) |
| } |
| [sym::ffi_pure, ..] => self.check_ffi_pure(attr.span, attrs, target), |
| [sym::ffi_const, ..] => self.check_ffi_const(attr.span, target), |
| [sym::rustc_const_unstable, ..] |
| | [sym::rustc_const_stable, ..] |
| | [sym::unstable, ..] |
| | [sym::stable, ..] |
| | [sym::rustc_allowed_through_unstable_modules, ..] |
| | [sym::rustc_promotable, ..] => self.check_stability_promotable(attr, target), |
| [sym::link_ordinal, ..] => self.check_link_ordinal(attr, span, target), |
| [sym::rustc_confusables, ..] => self.check_confusables(attr, target), |
| [sym::rustc_safe_intrinsic, ..] => { |
| self.check_rustc_safe_intrinsic(hir_id, attr, span, target) |
| } |
| [sym::cold, ..] => self.check_cold(hir_id, attr, span, target), |
| [sym::link, ..] => self.check_link(hir_id, attr, span, target), |
| [sym::link_name, ..] => self.check_link_name(hir_id, attr, span, target), |
| [sym::link_section, ..] => self.check_link_section(hir_id, attr, span, target), |
| [sym::no_mangle, ..] => self.check_no_mangle(hir_id, attr, span, target), |
| [sym::deprecated, ..] => self.check_deprecated(hir_id, attr, span, target), |
| [sym::macro_use, ..] | [sym::macro_escape, ..] => { |
| self.check_macro_use(hir_id, attr, target) |
| } |
| [sym::path, ..] => self.check_generic_attr(hir_id, attr, target, Target::Mod), |
| [sym::macro_export, ..] => self.check_macro_export(hir_id, attr, target), |
| [sym::ignore, ..] | [sym::should_panic, ..] => { |
| self.check_generic_attr(hir_id, attr, target, Target::Fn) |
| } |
| [sym::automatically_derived, ..] => { |
| self.check_generic_attr(hir_id, attr, target, Target::Impl) |
| } |
| [sym::no_implicit_prelude, ..] => { |
| self.check_generic_attr(hir_id, attr, target, Target::Mod) |
| } |
| [sym::rustc_object_lifetime_default, ..] => self.check_object_lifetime_default(hir_id), |
| [sym::proc_macro, ..] => { |
| self.check_proc_macro(hir_id, target, ProcMacroKind::FunctionLike) |
| } |
| [sym::proc_macro_attribute, ..] => { |
| self.check_proc_macro(hir_id, target, ProcMacroKind::Attribute); |
| } |
| [sym::proc_macro_derive, ..] => { |
| self.check_generic_attr(hir_id, attr, target, Target::Fn); |
| self.check_proc_macro(hir_id, target, ProcMacroKind::Derive) |
| } |
| [sym::coroutine, ..] => { |
| self.check_coroutine(attr, target); |
| } |
| [sym::linkage, ..] => self.check_linkage(attr, span, target), |
| [sym::rustc_pub_transparent, ..] => self.check_rustc_pub_transparent( attr.span, span, attrs), |
| [ |
| // ok |
| sym::allow |
| | sym::expect |
| | sym::warn |
| | sym::deny |
| | sym::forbid |
| | sym::cfg |
| | sym::cfg_attr |
| // need to be fixed |
| | sym::cfi_encoding // FIXME(cfi_encoding) |
| | sym::pointee // FIXME(derive_smart_pointer) |
| | sym::omit_gdb_pretty_printer_section // FIXME(omit_gdb_pretty_printer_section) |
| | sym::used // handled elsewhere to restrict to static items |
| | sym::repr // handled elsewhere to restrict to type decls items |
| | 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::allow_internal_unsafe |
| | sym::fundamental |
| | sym::lang |
| | sym::needs_allocator |
| | sym::default_lib_allocator |
| | sym::start |
| | sym::custom_mir, |
| .. |
| ] => {} |
| [name, ..] => { |
| match BUILTIN_ATTRIBUTE_MAP.get(name) { |
| // checked below |
| Some(BuiltinAttribute { type_: AttributeType::CrateLevel, .. }) => {} |
| Some(_) => { |
| // 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 { |
| if let Some(BuiltinAttribute { type_: AttributeType::CrateLevel, .. }) = |
| attr.ident().and_then(|ident| BUILTIN_ATTRIBUTE_MAP.get(&ident.name)) |
| { |
| match attr.style { |
| ast::AttrStyle::Outer => self.tcx.emit_node_span_lint( |
| UNUSED_ATTRIBUTES, |
| hir_id, |
| attr.span, |
| errors::OuterCrateLevelAttr, |
| ), |
| 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) |
| } |
| |
| self.check_repr(attrs, span, target, item, hir_id); |
| self.check_used(attrs, target, span); |
| } |
| |
| fn inline_attr_str_error_with_macro_def(&self, hir_id: HirId, attr: &Attribute, sym: &str) { |
| self.tcx.emit_node_span_lint( |
| UNUSED_ATTRIBUTES, |
| hir_id, |
| attr.span, |
| errors::IgnoredAttrWithMacro { sym }, |
| ); |
| } |
| |
| fn inline_attr_str_error_without_macro_def(&self, hir_id: HirId, attr: &Attribute, sym: &str) { |
| self.tcx.emit_node_span_lint( |
| UNUSED_ATTRIBUTES, |
| hir_id, |
| attr.span, |
| errors::IgnoredAttr { sym }, |
| ); |
| } |
| |
| /// Checks if `#[diagnostic::do_not_recommend]` is applied on a trait impl. |
| fn check_do_not_recommend(&self, attr_span: Span, hir_id: HirId, target: Target) { |
| if !matches!(target, Target::Impl) { |
| self.tcx.emit_node_span_lint( |
| UNKNOWN_OR_MALFORMED_DIAGNOSTIC_ATTRIBUTES, |
| hir_id, |
| attr_span, |
| errors::IncorrectDoNotRecommendLocation, |
| ); |
| } |
| } |
| |
| /// 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( |
| UNKNOWN_OR_MALFORMED_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: &Attribute, span: Span, target: Target) { |
| match target { |
| Target::Fn |
| | Target::Closure |
| | Target::Method(MethodKind::Trait { body: true } | MethodKind::Inherent) => {} |
| Target::Method(MethodKind::Trait { body: false }) | Target::ForeignFn => { |
| self.tcx.emit_node_span_lint( |
| UNUSED_ATTRIBUTES, |
| hir_id, |
| attr.span, |
| errors::IgnoredInlineAttrFnProto, |
| ) |
| } |
| // FIXME(#65833): We permit associated consts to have an `#[inline]` 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::AssocConst => self.tcx.emit_node_span_lint( |
| UNUSED_ATTRIBUTES, |
| hir_id, |
| attr.span, |
| errors::IgnoredInlineAttrConstants, |
| ), |
| // FIXME(#80564): Same for fields, arms, and macro defs |
| Target::Field | Target::Arm | Target::MacroDef => { |
| self.inline_attr_str_error_with_macro_def(hir_id, attr, "inline") |
| } |
| _ => { |
| self.dcx().emit_err(errors::InlineNotFnOrClosure { |
| attr_span: attr.span, |
| defn_span: span, |
| }); |
| } |
| } |
| } |
| |
| /// Checks that `#[coverage(..)]` is applied to a function/closure/method, |
| /// or to an impl block or module. |
| fn check_coverage(&self, attr: &Attribute, span: Span, target: Target) { |
| match target { |
| Target::Fn |
| | Target::Closure |
| | Target::Method(MethodKind::Trait { body: true } | MethodKind::Inherent) |
| | Target::Impl |
| | Target::Mod => {} |
| |
| _ => { |
| self.dcx().emit_err(errors::CoverageNotFnOrClosure { |
| attr_span: attr.span, |
| defn_span: span, |
| }); |
| } |
| } |
| } |
| |
| /// Checks that `#[optimize(..)]` is applied to a function/closure/method, |
| /// or to an impl block or module. |
| // FIXME(#128488): this should probably be elevated to an error? |
| fn check_optimize(&self, hir_id: HirId, attr: &Attribute, target: Target) { |
| match target { |
| Target::Fn |
| | Target::Closure |
| | Target::Method(MethodKind::Trait { body: true } | MethodKind::Inherent) |
| | Target::Impl |
| | Target::Mod => {} |
| |
| _ => { |
| self.tcx.emit_node_span_lint( |
| UNUSED_ATTRIBUTES, |
| hir_id, |
| attr.span, |
| errors::OptimizeNotFnOrClosure, |
| ); |
| } |
| } |
| } |
| |
| /// Checks that `#[no_sanitize(..)]` is applied to a function or method. |
| fn check_no_sanitize(&self, hir_id: HirId, attr: &Attribute, span: Span, target: Target) { |
| self.check_applied_to_fn_or_method(hir_id, attr, span, target) |
| } |
| |
| fn check_generic_attr( |
| &self, |
| hir_id: HirId, |
| attr: &Attribute, |
| target: Target, |
| allowed_target: Target, |
| ) { |
| if target != allowed_target { |
| self.tcx.emit_node_span_lint( |
| UNUSED_ATTRIBUTES, |
| hir_id, |
| attr.span, |
| errors::OnlyHasEffectOn { |
| attr_name: attr.name_or_empty(), |
| target_name: allowed_target.name().replace(' ', "_"), |
| }, |
| ); |
| } |
| } |
| |
| /// Checks if `#[naked]` is applied to a function definition. |
| fn check_naked( |
| &self, |
| hir_id: HirId, |
| attr: &Attribute, |
| span: Span, |
| target: Target, |
| attrs: &[Attribute], |
| ) { |
| // many attributes don't make sense in combination with #[naked]. |
| // Notable attributes that are incompatible with `#[naked]` are: |
| // |
| // * `#[inline]` |
| // * `#[track_caller]` |
| // * `#[test]`, `#[ignore]`, `#[should_panic]` |
| // |
| // NOTE: when making changes to this list, check that `error_codes/E0736.md` remains accurate |
| const ALLOW_LIST: &[rustc_span::Symbol] = &[ |
| // conditional compilation |
| sym::cfg, |
| sym::cfg_attr, |
| // testing (allowed here so better errors can be generated in `rustc_builtin_macros::test`) |
| sym::test, |
| sym::ignore, |
| sym::should_panic, |
| sym::bench, |
| // diagnostics |
| sym::allow, |
| sym::warn, |
| sym::deny, |
| sym::forbid, |
| sym::deprecated, |
| sym::must_use, |
| // abi, linking and FFI |
| sym::export_name, |
| sym::link_section, |
| sym::linkage, |
| sym::no_mangle, |
| sym::naked, |
| sym::instruction_set, |
| sym::repr, |
| // code generation |
| sym::cold, |
| sym::target_feature, |
| // documentation |
| sym::doc, |
| ]; |
| |
| match target { |
| Target::Fn |
| | Target::Method(MethodKind::Trait { body: true } | MethodKind::Inherent) => { |
| for other_attr in attrs { |
| // this covers "sugared doc comments" of the form `/// ...` |
| // it does not cover `#[doc = "..."]`, which is handled below |
| if other_attr.is_doc_comment() { |
| continue; |
| } |
| |
| if !ALLOW_LIST.iter().any(|name| other_attr.has_name(*name)) { |
| self.dcx().emit_err(errors::NakedFunctionIncompatibleAttribute { |
| span: other_attr.span, |
| naked_span: attr.span, |
| attr: other_attr.name_or_empty(), |
| }); |
| |
| return; |
| } |
| } |
| } |
| // FIXME(#80564): We permit struct fields, match arms and macro defs to have an |
| // `#[naked]` 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, "naked") |
| } |
| _ => { |
| self.dcx().emit_err(errors::AttrShouldBeAppliedToFn { |
| attr_span: attr.span, |
| defn_span: span, |
| on_crate: hir_id == CRATE_HIR_ID, |
| }); |
| } |
| } |
| } |
| |
| /// Checks if `#[cmse_nonsecure_entry]` is applied to a function definition. |
| fn check_cmse_nonsecure_entry( |
| &self, |
| hir_id: HirId, |
| attr: &Attribute, |
| span: Span, |
| target: Target, |
| ) { |
| match target { |
| Target::Fn |
| | Target::Method(MethodKind::Trait { body: true } | MethodKind::Inherent) => {} |
| _ => { |
| self.dcx().emit_err(errors::AttrShouldBeAppliedToFn { |
| attr_span: attr.span, |
| defn_span: span, |
| on_crate: hir_id == CRATE_HIR_ID, |
| }); |
| } |
| } |
| } |
| |
| /// 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], |
| span: Span, |
| 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, |
| }); |
| } |
| } |
| Target::Method(..) | Target::ForeignFn | Target::Closure => {} |
| // FIXME(#80564): We permit struct fields, match arms and macro defs to have an |
| // `#[track_caller]` 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 => { |
| for attr in attrs { |
| self.inline_attr_str_error_with_macro_def(hir_id, attr, "track_caller"); |
| } |
| } |
| _ => { |
| self.dcx().emit_err(errors::TrackedCallerWrongLocation { |
| attr_span, |
| defn_span: span, |
| on_crate: hir_id == CRATE_HIR_ID, |
| }); |
| } |
| } |
| } |
| |
| /// Checks if the `#[non_exhaustive]` attribute on an `item` is valid. |
| fn check_non_exhaustive(&self, hir_id: HirId, attr: &Attribute, span: Span, target: Target) { |
| match target { |
| Target::Struct | Target::Enum | Target::Variant => {} |
| // FIXME(#80564): We permit struct fields, match arms and macro defs to have an |
| // `#[non_exhaustive]` 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, "non_exhaustive"); |
| } |
| _ => { |
| self.dcx().emit_err(errors::NonExhaustiveWrongLocation { |
| attr_span: attr.span, |
| defn_span: span, |
| }); |
| } |
| } |
| } |
| |
| /// Checks if the `#[marker]` attribute on an `item` is valid. |
| fn check_marker(&self, hir_id: HirId, attr: &Attribute, span: Span, target: Target) { |
| match target { |
| Target::Trait => {} |
| // FIXME(#80564): We permit struct fields, match arms and macro defs to have an |
| // `#[marker]` 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, "marker"); |
| } |
| _ => { |
| self.dcx().emit_err(errors::AttrShouldBeAppliedToTrait { |
| attr_span: attr.span, |
| defn_span: span, |
| }); |
| } |
| } |
| } |
| |
| /// Checks if the `#[target_feature]` attribute on `item` is valid. |
| fn check_target_feature( |
| &self, |
| hir_id: HirId, |
| attr: &Attribute, |
| span: Span, |
| target: Target, |
| attrs: &[Attribute], |
| ) { |
| match target { |
| 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: attr.span, |
| name: lang_item, |
| sig_span: sig.span, |
| }); |
| } |
| } |
| Target::Method(MethodKind::Trait { body: true } | MethodKind::Inherent) => {} |
| // FIXME: #[target_feature] was previously erroneously allowed on statements and some |
| // crates used this, so only emit a warning. |
| Target::Statement => { |
| self.tcx.emit_node_span_lint( |
| UNUSED_ATTRIBUTES, |
| hir_id, |
| attr.span, |
| errors::TargetFeatureOnStatement, |
| ); |
| } |
| // FIXME(#80564): We permit struct fields, match arms and macro defs to have an |
| // `#[target_feature]` 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, "target_feature"); |
| } |
| _ => { |
| self.dcx().emit_err(errors::AttrShouldBeAppliedToFn { |
| attr_span: attr.span, |
| defn_span: span, |
| on_crate: hir_id == CRATE_HIR_ID, |
| }); |
| } |
| } |
| } |
| |
| /// 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: &NestedMetaItem, attr_name: &str) { |
| self.dcx().emit_err(errors::DocExpectStr { attr_span: meta.span(), attr_name }); |
| } |
| |
| fn check_doc_alias_value( |
| &self, |
| meta: &NestedMetaItem, |
| doc_alias: Symbol, |
| hir_id: HirId, |
| target: Target, |
| is_list: bool, |
| aliases: &mut FxHashMap<String, Span>, |
| ) { |
| 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 == kw::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 => { |
| 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); |
| if Target::from_item(containing_item) == Target::Impl { |
| 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 => Some(target.name()), |
| Target::ExternCrate |
| | Target::Use |
| | Target::Static |
| | Target::Const |
| | Target::Fn |
| | Target::Mod |
| | Target::GlobalAsm |
| | Target::TyAlias |
| | Target::OpaqueTy |
| | 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 => None, |
| } { |
| tcx.dcx().emit_err(errors::DocAliasBadLocation { span, attr_str, location }); |
| return; |
| } |
| let item_name = self.tcx.hir().name(hir_id); |
| if item_name == 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: &NestedMetaItem, |
| hir_id: HirId, |
| target: Target, |
| aliases: &mut FxHashMap<String, Span>, |
| ) { |
| 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(&self, meta: &NestedMetaItem, hir_id: HirId) { |
| let doc_keyword = meta.value_str().unwrap_or(kw::Empty); |
| if doc_keyword == kw::Empty { |
| self.doc_attr_str_error(meta, "keyword"); |
| return; |
| } |
| 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::DocKeywordEmptyMod { span: meta.span() }); |
| return; |
| } |
| } |
| _ => { |
| self.dcx().emit_err(errors::DocKeywordNotMod { span: meta.span() }); |
| return; |
| } |
| } |
| if !rustc_lexer::is_ident(doc_keyword.as_str()) { |
| self.dcx().emit_err(errors::DocKeywordInvalidIdent { |
| span: meta.name_value_literal_span().unwrap_or_else(|| meta.span()), |
| doc_keyword, |
| }); |
| } |
| } |
| |
| fn check_doc_fake_variadic(&self, meta: &NestedMetaItem, 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 = matches!(&i.self_ty.kind, hir::TyKind::Tup([_])) |
| || if let hir::TyKind::BareFn(bare_fn_ty) = &i.self_ty.kind { |
| bare_fn_ty.decl.inputs.len() == 1 |
| } else { |
| false |
| } |
| || if let Some(&[hir::GenericArg::Type(ty)]) = i |
| .of_trait |
| .as_ref() |
| .and_then(|trait_ref| 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() }); |
| } |
| } |
| } |
| |
| /// 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, |
| attr: &Attribute, |
| meta: &NestedMetaItem, |
| hir_id: HirId, |
| target: Target, |
| specified_inline: &mut Option<(bool, Span)>, |
| ) { |
| match target { |
| Target::Use | Target::ExternCrate => { |
| let do_inline = meta.name_or_empty() == 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: (attr.style == AttrStyle::Outer) |
| .then(|| self.tcx.hir().span(hir_id)), |
| }, |
| ); |
| } |
| } |
| } |
| |
| fn check_doc_masked( |
| &self, |
| attr: &Attribute, |
| meta: &NestedMetaItem, |
| 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: (attr.style == AttrStyle::Outer) |
| .then(|| self.tcx.hir().span(hir_id)), |
| }, |
| ); |
| return; |
| } |
| |
| if self.tcx.extern_mod_stmt_cnum(hir_id.owner).is_none() { |
| self.tcx.emit_node_span_lint( |
| INVALID_DOC_ATTRIBUTES, |
| hir_id, |
| meta.span(), |
| errors::DocMaskedNotExternCrateSelf { |
| attr_span: meta.span(), |
| item_span: (attr.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: &NestedMetaItem, |
| 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, |
| meta: &NestedMetaItem, |
| 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 = (attr.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. Returns `true` if |
| /// valid. |
| fn check_test_attr(&self, meta: &NestedMetaItem, hir_id: HirId) { |
| if let Some(metas) = meta.meta_item_list() { |
| for i_meta in metas { |
| match (i_meta.name_or_empty(), i_meta.meta_item()) { |
| (sym::attr | sym::no_crate_inject, _) => {} |
| (_, 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: &NestedMetaItem, 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, |
| hir_id: HirId, |
| target: Target, |
| specified_inline: &mut Option<(bool, Span)>, |
| aliases: &mut FxHashMap<String, Span>, |
| ) { |
| if let Some(mi) = attr.meta() |
| && let Some(list) = mi.meta_item_list() |
| { |
| for meta in list { |
| if let Some(i_meta) = meta.meta_item() { |
| match i_meta.name_or_empty() { |
| sym::alias => { |
| if self.check_attr_not_crate_level(meta, hir_id, "alias") { |
| self.check_doc_alias(meta, hir_id, target, aliases); |
| } |
| } |
| |
| sym::keyword => { |
| if self.check_attr_not_crate_level(meta, hir_id, "keyword") { |
| self.check_doc_keyword(meta, hir_id); |
| } |
| } |
| |
| sym::fake_variadic => { |
| if self.check_attr_not_crate_level(meta, hir_id, "fake_variadic") { |
| self.check_doc_fake_variadic(meta, hir_id); |
| } |
| } |
| |
| sym::test => { |
| if self.check_attr_crate_level(attr, meta, hir_id) { |
| self.check_test_attr(meta, hir_id); |
| } |
| } |
| |
| 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, meta, hir_id); |
| } |
| |
| sym::cfg_hide => { |
| if self.check_attr_crate_level(attr, meta, hir_id) { |
| self.check_doc_cfg_hide(meta, hir_id); |
| } |
| } |
| |
| sym::inline | sym::no_inline => { |
| self.check_doc_inline(attr, meta, hir_id, target, specified_inline) |
| } |
| |
| sym::masked => self.check_doc_masked(attr, meta, hir_id, target), |
| |
| // no_default_passes: deprecated |
| // passes: deprecated |
| // plugins: removed, but rustdoc warns about it itself |
| sym::cfg |
| | sym::hidden |
| | sym::no_default_passes |
| | sym::notable_trait |
| | sym::passes |
| | sym::plugins => {} |
| |
| sym::rust_logo => { |
| if self.check_attr_crate_level(attr, 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 attr.style { |
| AttrStyle::Inner => "!", |
| AttrStyle::Outer => "", |
| }, |
| sugg: (attr.meta().unwrap().span, applicability), |
| }, |
| ); |
| } 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, |
| ); |
| } |
| } |
| } |
| } |
| |
| /// Warns against some misuses of `#[pass_by_value]` |
| fn check_pass_by_value(&self, attr: &Attribute, span: Span, target: Target) { |
| match target { |
| Target::Struct | Target::Enum | Target::TyAlias => {} |
| _ => { |
| self.dcx().emit_err(errors::PassByValue { attr_span: attr.span, span }); |
| } |
| } |
| } |
| |
| fn check_allow_incoherent_impl(&self, attr: &Attribute, span: Span, target: Target) { |
| match target { |
| Target::Method(MethodKind::Inherent) => {} |
| _ => { |
| self.dcx().emit_err(errors::AllowIncoherentImpl { attr_span: attr.span, span }); |
| } |
| } |
| } |
| |
| 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], target: Target) { |
| if target != Target::ForeignFn { |
| self.dcx().emit_err(errors::FfiPureInvalidTarget { attr_span }); |
| return; |
| } |
| if attrs.iter().any(|a| a.has_name(sym::ffi_const)) { |
| // `#[ffi_const]` functions cannot be `#[ffi_pure]` |
| self.dcx().emit_err(errors::BothFfiConstAndPure { attr_span }); |
| } |
| } |
| |
| fn check_ffi_const(&self, attr_span: Span, target: Target) { |
| if target != Target::ForeignFn { |
| self.dcx().emit_err(errors::FfiConstInvalidTarget { attr_span }); |
| } |
| } |
| |
| /// Warns against some misuses of `#[must_use]` |
| fn check_must_use(&self, hir_id: HirId, attr: &Attribute, target: Target) { |
| if !matches!( |
| target, |
| Target::Fn |
| | Target::Enum |
| | Target::Struct |
| | Target::Union |
| | Target::Method(_) |
| | Target::ForeignFn |
| // `impl Trait` in return position can trip |
| // `unused_must_use` if `Trait` is marked as |
| // `#[must_use]` |
| | Target::Trait |
| ) { |
| let article = match target { |
| Target::ExternCrate |
| | Target::OpaqueTy |
| | Target::Enum |
| | Target::Impl |
| | Target::Expression |
| | Target::Arm |
| | Target::AssocConst |
| | Target::AssocTy => "an", |
| _ => "a", |
| }; |
| |
| self.tcx.emit_node_span_lint( |
| UNUSED_ATTRIBUTES, |
| hir_id, |
| attr.span, |
| errors::MustUseNoEffect { article, target }, |
| ); |
| } |
| } |
| |
| /// 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: &Attribute) { |
| 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(trait_) = impl_.of_trait |
| && let Some(def_id) = trait_.trait_def_id() |
| && self.tcx.is_lang_item(def_id, hir::LangItem::Drop) |
| { |
| return; |
| } |
| |
| self.dcx().emit_err(errors::InvalidMayDangle { attr_span: attr.span }); |
| } |
| |
| /// Checks if `#[cold]` is applied to a non-function. |
| fn check_cold(&self, hir_id: HirId, attr: &Attribute, span: Span, target: Target) { |
| match target { |
| Target::Fn | Target::Method(..) | Target::ForeignFn | Target::Closure => {} |
| // FIXME(#80564): We permit struct fields, match arms and macro defs to have an |
| // `#[cold]` 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, "cold"); |
| } |
| _ => { |
| // FIXME: #[cold] was previously allowed on non-functions and some crates used |
| // this, so only emit a warning. |
| self.tcx.emit_node_span_lint( |
| UNUSED_ATTRIBUTES, |
| hir_id, |
| attr.span, |
| errors::Cold { span, on_crate: hir_id == CRATE_HIR_ID }, |
| ); |
| } |
| } |
| } |
| |
| /// Checks if `#[link]` is applied to an item other than a foreign module. |
| fn check_link(&self, hir_id: HirId, attr: &Attribute, 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, Abi::Rust | Abi::RustIntrinsic) |
| { |
| return; |
| } |
| |
| self.tcx.emit_node_span_lint( |
| UNUSED_ATTRIBUTES, |
| hir_id, |
| attr.span, |
| errors::Link { span: (target != Target::ForeignMod).then_some(span) }, |
| ); |
| } |
| |
| /// Checks if `#[link_name]` is applied to an item other than a foreign function or static. |
| fn check_link_name(&self, hir_id: HirId, attr: &Attribute, span: Span, target: Target) { |
| match target { |
| Target::ForeignFn | Target::ForeignStatic => {} |
| // FIXME(#80564): We permit struct fields, match arms and macro defs to have an |
| // `#[link_name]` 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, "link_name"); |
| } |
| _ => { |
| // FIXME: #[cold] was previously allowed on non-functions/statics and some crates |
| // used this, so only emit a warning. |
| let attr_span = matches!(target, Target::ForeignMod).then_some(attr.span); |
| if let Some(s) = attr.value_str() { |
| self.tcx.emit_node_span_lint( |
| UNUSED_ATTRIBUTES, |
| hir_id, |
| attr.span, |
| errors::LinkName { span, attr_span, value: s.as_str() }, |
| ); |
| } else { |
| self.tcx.emit_node_span_lint( |
| UNUSED_ATTRIBUTES, |
| hir_id, |
| attr.span, |
| errors::LinkName { span, attr_span, value: "..." }, |
| ); |
| }; |
| } |
| } |
| } |
| |
| /// 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, "no_link"); |
| } |
| _ => { |
| self.dcx().emit_err(errors::NoLink { attr_span: attr.span, span }); |
| } |
| } |
| } |
| |
| fn is_impl_item(&self, hir_id: HirId) -> bool { |
| matches!(self.tcx.hir_node(hir_id), hir::Node::ImplItem(..)) |
| } |
| |
| /// Checks if `#[export_name]` is applied to a function or static. |
| fn check_export_name(&self, hir_id: HirId, attr: &Attribute, span: Span, target: Target) { |
| match target { |
| Target::Static | Target::Fn => {} |
| Target::Method(..) if self.is_impl_item(hir_id) => {} |
| // FIXME(#80564): We permit struct fields, match arms and macro defs to have an |
| // `#[export_name]` 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, "export_name"); |
| } |
| _ => { |
| self.dcx().emit_err(errors::ExportName { attr_span: attr.span, span }); |
| } |
| } |
| } |
| |
| fn check_rustc_layout_scalar_valid_range(&self, attr: &Attribute, span: Span, target: Target) { |
| if target != Target::Struct { |
| self.dcx().emit_err(errors::RustcLayoutScalarValidRangeNotStruct { |
| attr_span: attr.span, |
| span, |
| }); |
| return; |
| } |
| |
| let Some(list) = attr.meta_item_list() else { |
| return; |
| }; |
| |
| if !matches!(&list[..], &[NestedMetaItem::Lit(MetaItemLit { kind: LitKind::Int(..), .. })]) |
| { |
| self.tcx |
| .dcx() |
| .emit_err(errors::RustcLayoutScalarValidRangeArg { attr_span: attr.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<ItemLike<'_>>, |
| ) { |
| 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(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: &Attribute, |
| span: Span, |
| target: Target, |
| ) { |
| let is_function = matches!(target, Target::Fn | Target::Method(..)); |
| if !is_function { |
| self.dcx().emit_err(errors::AttrShouldBeAppliedToFn { |
| attr_span: attr.span, |
| defn_span: span, |
| on_crate: hir_id == CRATE_HIR_ID, |
| }); |
| } |
| } |
| |
| /// Checks that the `#[rustc_lint_query_instability]` attribute is only applied to a function |
| /// or method. |
| fn check_rustc_lint_query_instability( |
| &self, |
| hir_id: HirId, |
| attr: &Attribute, |
| span: Span, |
| target: Target, |
| ) { |
| self.check_applied_to_fn_or_method(hir_id, attr, span, target) |
| } |
| |
| /// Checks that the `#[rustc_lint_diagnostics]` attribute is only applied to a function or |
| /// method. |
| fn check_rustc_lint_diagnostics( |
| &self, |
| hir_id: HirId, |
| attr: &Attribute, |
| span: Span, |
| target: Target, |
| ) { |
| self.check_applied_to_fn_or_method(hir_id, attr, span, target) |
| } |
| |
| /// 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: &Attribute, span: Span, target: Target) { |
| match target { |
| Target::Trait => {} |
| _ => { |
| self.dcx().emit_err(errors::AttrShouldBeAppliedToTrait { |
| attr_span: attr.span, |
| defn_span: span, |
| }); |
| } |
| } |
| } |
| |
| /// Checks if `#[link_section]` is applied to a function or static. |
| fn check_link_section(&self, hir_id: HirId, attr: &Attribute, span: Span, target: Target) { |
| match target { |
| Target::Static | Target::Fn | Target::Method(..) => {} |
| // FIXME(#80564): We permit struct fields, match arms and macro defs to have an |
| // `#[link_section]` 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, "link_section"); |
| } |
| _ => { |
| // FIXME: #[link_section] was previously allowed on non-functions/statics and some |
| // crates used this, so only emit a warning. |
| self.tcx.emit_node_span_lint( |
| UNUSED_ATTRIBUTES, |
| hir_id, |
| attr.span, |
| errors::LinkSection { span }, |
| ); |
| } |
| } |
| } |
| |
| /// Checks if `#[no_mangle]` is applied to a function or static. |
| fn check_no_mangle(&self, hir_id: HirId, attr: &Attribute, span: Span, target: Target) { |
| match target { |
| Target::Static | Target::Fn => {} |
| Target::Method(..) if self.is_impl_item(hir_id) => {} |
| // FIXME(#80564): We permit struct fields, match arms and macro defs to have an |
| // `#[no_mangle]` 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, "no_mangle"); |
| } |
| // FIXME: #[no_mangle] was previously allowed on non-functions/statics, this should be an error |
| // The error should specify that the item that is wrong is specifically a *foreign* fn/static |
| // otherwise the error seems odd |
| Target::ForeignFn | Target::ForeignStatic => { |
| let foreign_item_kind = match target { |
| Target::ForeignFn => "function", |
| Target::ForeignStatic => "static", |
| _ => unreachable!(), |
| }; |
| self.tcx.emit_node_span_lint( |
| UNUSED_ATTRIBUTES, |
| hir_id, |
| attr.span, |
| errors::NoMangleForeign { span, attr_span: attr.span, foreign_item_kind }, |
| ); |
| } |
| _ => { |
| // FIXME: #[no_mangle] was previously allowed on non-functions/statics and some |
| // crates used this, so only emit a warning. |
| self.tcx.emit_node_span_lint( |
| UNUSED_ATTRIBUTES, |
| hir_id, |
| attr.span, |
| errors::NoMangle { span }, |
| ); |
| } |
| } |
| } |
| |
| /// Checks if the `#[repr]` attributes on `item` are valid. |
| fn check_repr( |
| &self, |
| attrs: &[Attribute], |
| span: Span, |
| target: Target, |
| item: Option<ItemLike<'_>>, |
| hir_id: HirId, |
| ) { |
| // Extract the names of all repr hints, e.g., [foo, bar, align] for: |
| // ``` |
| // #[repr(foo)] |
| // #[repr(bar, align(8))] |
| // ``` |
| let hints: Vec<_> = attrs |
| .iter() |
| .filter(|attr| attr.has_name(sym::repr)) |
| .filter_map(|attr| attr.meta_item_list()) |
| .flatten() |
| .collect(); |
| |
| 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 hint in &hints { |
| if !hint.is_meta_item() { |
| self.dcx().emit_err(errors::ReprIdent { span: hint.span() }); |
| continue; |
| } |
| |
| match hint.name_or_empty() { |
| sym::Rust => { |
| is_explicit_rust = true; |
| } |
| sym::C => { |
| is_c = true; |
| match target { |
| Target::Struct | Target::Union | Target::Enum => continue, |
| _ => { |
| self.dcx().emit_err(errors::AttrApplication::StructEnumUnion { |
| hint_span: hint.span(), |
| span, |
| }); |
| } |
| } |
| } |
| sym::align => { |
| if let (Target::Fn | Target::Method(MethodKind::Inherent), false) = |
| (target, self.tcx.features().fn_align) |
| { |
| feature_err( |
| &self.tcx.sess, |
| sym::fn_align, |
| hint.span(), |
| fluent::passes_repr_align_function, |
| ) |
| .emit(); |
| } |
| |
| match target { |
| Target::Struct |
| | Target::Union |
| | Target::Enum |
| | Target::Fn |
| | Target::Method(_) => continue, |
| _ => { |
| self.dcx().emit_err( |
| errors::AttrApplication::StructEnumFunctionMethodUnion { |
| hint_span: hint.span(), |
| span, |
| }, |
| ); |
| } |
| } |
| } |
| sym::packed => { |
| if target != Target::Struct && target != Target::Union { |
| self.dcx().emit_err(errors::AttrApplication::StructUnion { |
| hint_span: hint.span(), |
| span, |
| }); |
| } else { |
| continue; |
| } |
| } |
| sym::simd => { |
| is_simd = true; |
| if target != Target::Struct { |
| self.dcx().emit_err(errors::AttrApplication::Struct { |
| hint_span: hint.span(), |
| span, |
| }); |
| } else { |
| continue; |
| } |
| } |
| sym::transparent => { |
| is_transparent = true; |
| match target { |
| Target::Struct | Target::Union | Target::Enum => continue, |
| _ => { |
| self.dcx().emit_err(errors::AttrApplication::StructEnumUnion { |
| hint_span: hint.span(), |
| span, |
| }); |
| } |
| } |
| } |
| sym::i8 |
| | sym::u8 |
| | sym::i16 |
| | sym::u16 |
| | sym::i32 |
| | sym::u32 |
| | sym::i64 |
| | sym::u64 |
| | sym::i128 |
| | sym::u128 |
| | sym::isize |
| | sym::usize => { |
| int_reprs += 1; |
| if target != Target::Enum { |
| self.dcx().emit_err(errors::AttrApplication::Enum { |
| hint_span: hint.span(), |
| span, |
| }); |
| } else { |
| continue; |
| } |
| } |
| _ => { |
| self.dcx().emit_err(errors::UnrecognizedReprHint { span: hint.span() }); |
| continue; |
| } |
| }; |
| } |
| |
| // 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 = hints.iter().map(|hint| hint.span()); |
| |
| // Error on repr(transparent, <anything else>). |
| if is_transparent && hints.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 { |
| return is_c_like_enum(item); |
| } |
| return false; |
| })) |
| { |
| self.tcx.emit_node_span_lint( |
| CONFLICTING_REPR_HINTS, |
| hir_id, |
| hint_spans.collect::<Vec<Span>>(), |
| errors::ReprConflictingLint, |
| ); |
| } |
| } |
| |
| fn check_used(&self, attrs: &[Attribute], target: Target, target_span: Span) { |
| let mut used_linker_span = None; |
| let mut used_compiler_span = None; |
| for attr in attrs.iter().filter(|attr| attr.has_name(sym::used)) { |
| if target != Target::Static { |
| self.dcx().emit_err(errors::UsedStatic { |
| attr_span: attr.span, |
| span: target_span, |
| target: target.name(), |
| }); |
| } |
| let inner = attr.meta_item_list(); |
| match inner.as_deref() { |
| Some([item]) if item.has_name(sym::linker) => { |
| if used_linker_span.is_none() { |
| used_linker_span = Some(attr.span); |
| } |
| } |
| Some([item]) if item.has_name(sym::compiler) => { |
| if used_compiler_span.is_none() { |
| used_compiler_span = Some(attr.span); |
| } |
| } |
| Some(_) => { |
| // This error case is handled in rustc_hir_analysis::collect. |
| } |
| None => { |
| // Default case (compiler) when arg isn't defined. |
| if used_compiler_span.is_none() { |
| used_compiler_span = Some(attr.span); |
| } |
| } |
| } |
| } |
| if let (Some(linker_span), Some(compiler_span)) = (used_linker_span, used_compiler_span) { |
| self.tcx |
| .dcx() |
| .emit_err(errors::UsedCompilerLinker { spans: vec![linker_span, compiler_span] }); |
| } |
| } |
| |
| /// Outputs an error for `#[allow_internal_unstable]` which can only be applied to macros. |
| /// (Allows proc_macro functions) |
| fn check_allow_internal_unstable( |
| &self, |
| hir_id: HirId, |
| attr: &Attribute, |
| span: Span, |
| target: Target, |
| attrs: &[Attribute], |
| ) { |
| debug!("Checking target: {:?}", target); |
| match target { |
| Target::Fn => { |
| for attr in attrs { |
| if attr.is_proc_macro_attr() { |
| debug!("Is proc macro attr"); |
| return; |
| } |
| } |
| debug!("Is not proc macro attr"); |
| } |
| Target::MacroDef => {} |
| // FIXME(#80564): We permit struct fields and match arms to have an |
| // `#[allow_internal_unstable]` 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 => self.inline_attr_str_error_without_macro_def( |
| hir_id, |
| attr, |
| "allow_internal_unstable", |
| ), |
| _ => { |
| self.tcx |
| .dcx() |
| .emit_err(errors::AllowInternalUnstable { attr_span: 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: &Attribute, |
| span: Span, |
| target: Target, |
| ) { |
| match target { |
| Target::Fn | Target::Method(_) |
| if self.tcx.is_const_fn_raw(hir_id.expect_owner().to_def_id()) => {} |
| // FIXME(#80564): We permit struct fields and match arms to have an |
| // `#[allow_internal_unstable]` 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, "allow_internal_unstable") |
| } |
| _ => { |
| self.tcx |
| .dcx() |
| .emit_err(errors::RustcAllowConstFnUnstable { attr_span: attr.span, span }); |
| } |
| } |
| } |
| |
| fn check_rustc_safe_intrinsic( |
| &self, |
| hir_id: HirId, |
| attr: &Attribute, |
| span: Span, |
| target: Target, |
| ) { |
| if let Target::ForeignFn = target |
| && let hir::Node::Item(Item { |
| kind: ItemKind::ForeignMod { abi: Abi::RustIntrinsic, .. }, |
| .. |
| }) = self.tcx.parent_hir_node(hir_id) |
| { |
| return; |
| } |
| |
| self.dcx().emit_err(errors::RustcSafeIntrinsic { attr_span: attr.span, span }); |
| } |
| |
| fn check_rustc_std_internal_symbol(&self, attr: &Attribute, span: Span, target: Target) { |
| match target { |
| Target::Fn | Target::Static => {} |
| _ => { |
| self.tcx |
| .dcx() |
| .emit_err(errors::RustcStdInternalSymbol { attr_span: attr.span, span }); |
| } |
| } |
| } |
| |
| fn check_stability_promotable(&self, attr: &Attribute, target: Target) { |
| match target { |
| Target::Expression => { |
| self.dcx().emit_err(errors::StabilityPromotable { attr_span: attr.span }); |
| } |
| _ => {} |
| } |
| } |
| |
| fn check_link_ordinal(&self, attr: &Attribute, _span: Span, target: Target) { |
| match target { |
| Target::ForeignFn | Target::ForeignStatic => {} |
| _ => { |
| self.dcx().emit_err(errors::LinkOrdinal { attr_span: attr.span }); |
| } |
| } |
| } |
| |
| fn check_confusables(&self, attr: &Attribute, target: Target) { |
| match target { |
| Target::Method(MethodKind::Inherent) => { |
| let Some(meta) = attr.meta() else { |
| return; |
| }; |
| let ast::MetaItem { kind: MetaItemKind::List(ref metas), .. } = meta else { |
| return; |
| }; |
| |
| let mut candidates = Vec::new(); |
| |
| for meta in metas { |
| let NestedMetaItem::Lit(meta_lit) = meta else { |
| self.dcx().emit_err(errors::IncorrectMetaItem { |
| span: meta.span(), |
| suggestion: errors::IncorrectMetaItemSuggestion { |
| lo: meta.span().shrink_to_lo(), |
| hi: meta.span().shrink_to_hi(), |
| }, |
| }); |
| return; |
| }; |
| candidates.push(meta_lit.symbol); |
| } |
| |
| if candidates.is_empty() { |
| self.dcx().emit_err(errors::EmptyConfusables { span: attr.span }); |
| } |
| } |
| _ => { |
| self.dcx().emit_err(errors::Confusables { attr_span: attr.span }); |
| } |
| } |
| } |
| |
| fn check_deprecated(&self, hir_id: HirId, attr: &Attribute, _span: Span, target: Target) { |
| match target { |
| Target::Closure | Target::Expression | Target::Statement | Target::Arm => { |
| self.tcx.emit_node_span_lint( |
| UNUSED_ATTRIBUTES, |
| hir_id, |
| attr.span, |
| errors::Deprecated, |
| ); |
| } |
| _ => {} |
| } |
| } |
| |
| fn check_macro_use(&self, hir_id: HirId, attr: &Attribute, target: Target) { |
| let name = attr.name_or_empty(); |
| match target { |
| Target::ExternCrate | Target::Mod => {} |
| _ => { |
| self.tcx.emit_node_span_lint( |
| UNUSED_ATTRIBUTES, |
| hir_id, |
| attr.span, |
| errors::MacroUse { name }, |
| ); |
| } |
| } |
| } |
| |
| 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].name_or_empty() != sym::local_inner_macros { |
| self.tcx.emit_node_span_lint( |
| INVALID_MACRO_EXPORT_ARGUMENTS, |
| hir_id, |
| meta_item_list[0].span(), |
| errors::MacroExport::UnknownItem { |
| name: meta_item_list[0].name_or_empty(), |
| }, |
| ); |
| } |
| } |
| } 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) { |
| // Warn on useless empty attributes. |
| let note = if matches!( |
| attr.name_or_empty(), |
| sym::macro_use |
| | sym::allow |
| | sym::expect |
| | sym::warn |
| | sym::deny |
| | sym::forbid |
| | sym::feature |
| | sym::repr |
| | sym::target_feature |
| ) && attr.meta_item_list().is_some_and(|list| list.is_empty()) |
| { |
| errors::UnusedNote::EmptyList { name: attr.name_or_empty() } |
| } else if matches!( |
| attr.name_or_empty(), |
| 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_or_empty() } |
| } else if attr.name_or_empty() == 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(); |
| 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, |
| Abi::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(ValuePairs::PolySigs(ExpectedFound { |
| expected: ty::Binder::dummy(expected_sig), |
| found: ty::Binder::dummy(sig), |
| })), |
| terr, |
| false, |
| false, |
| ); |
| 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_coroutine(&self, attr: &Attribute, target: Target) { |
| match target { |
| Target::Closure => return, |
| _ => { |
| self.dcx().emit_err(errors::CoroutineOnNonClosure { span: attr.span }); |
| } |
| } |
| } |
| |
| fn check_linkage(&self, attr: &Attribute, span: Span, target: Target) { |
| match target { |
| Target::Fn |
| | Target::Method(..) |
| | Target::Static |
| | Target::ForeignStatic |
| | Target::ForeignFn => {} |
| _ => { |
| self.dcx().emit_err(errors::Linkage { attr_span: attr.span, span }); |
| } |
| } |
| } |
| |
| fn check_rustc_pub_transparent(&self, attr_span: Span, span: Span, attrs: &[Attribute]) { |
| if !attrs |
| .iter() |
| .filter(|attr| attr.has_name(sym::repr)) |
| .filter_map(|attr| attr.meta_item_list()) |
| .flatten() |
| .any(|nmi| nmi.has_name(sym::transparent)) |
| { |
| self.dcx().emit_err(errors::RustcPubTransparent { span, attr_span }); |
| } |
| } |
| } |
| |
| impl<'tcx> Visitor<'tcx> for CheckAttrVisitor<'tcx> { |
| type NestedFilter = nested_filter::OnlyBodies; |
| |
| fn nested_visit_map(&mut self) -> Self::Map { |
| self.tcx.hir() |
| } |
| |
| 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_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::repr, |
| sym::path, |
| sym::automatically_derived, |
| sym::start, |
| sym::rustc_main, |
| sym::derive, |
| sym::test, |
| sym::test_case, |
| sym::global_allocator, |
| sym::bench, |
| ]; |
| |
| for attr in attrs { |
| // This function should only be called with crate attributes |
| // which are inner attributes always but lets check to make sure |
| if attr.style == AttrStyle::Inner { |
| for attr_to_check in ATTRS_TO_CHECK { |
| if attr.has_name(*attr_to_check) { |
| let item = tcx |
| .hir() |
| .items() |
| .map(|id| tcx.hir().item(id)) |
| .find(|item| !item.span.is_dummy()) // Skip prelude `use`s |
| .map(|item| errors::ItemFollowingInnerAttr { |
| span: item.ident.span, |
| kind: item.kind.descr(), |
| }); |
| let err = tcx.dcx().create_err(errors::InvalidAttrAtCrateLevel { |
| span: attr.span, |
| sugg_span: tcx |
| .sess |
| .source_map() |
| .span_to_snippet(attr.span) |
| .ok() |
| .filter(|src| src.starts_with("#