rustc_attr_parsing/
context.rs

1use std::cell::RefCell;
2use std::collections::BTreeMap;
3use std::ops::{Deref, DerefMut};
4use std::sync::LazyLock;
5
6use private::Sealed;
7use rustc_ast::{AttrStyle, CRATE_NODE_ID, MetaItemLit, NodeId};
8use rustc_errors::{Diag, Diagnostic, Level};
9use rustc_feature::{AttributeTemplate, AttributeType};
10use rustc_hir::attrs::AttributeKind;
11use rustc_hir::lints::{AttributeLint, AttributeLintKind};
12use rustc_hir::{AttrPath, CRATE_HIR_ID, HirId};
13use rustc_session::Session;
14use rustc_span::{ErrorGuaranteed, Span, Symbol};
15
16use crate::AttributeParser;
17use crate::attributes::allow_unstable::{
18    AllowConstFnUnstableParser, AllowInternalUnstableParser, UnstableFeatureBoundParser,
19};
20use crate::attributes::body::CoroutineParser;
21use crate::attributes::codegen_attrs::{
22    ColdParser, CoverageParser, ExportNameParser, ForceTargetFeatureParser, NakedParser,
23    NoMangleParser, OptimizeParser, SanitizeParser, TargetFeatureParser, TrackCallerParser,
24    UsedParser,
25};
26use crate::attributes::confusables::ConfusablesParser;
27use crate::attributes::crate_level::{
28    CrateNameParser, MoveSizeLimitParser, PatternComplexityLimitParser, RecursionLimitParser,
29    TypeLengthLimitParser,
30};
31use crate::attributes::deprecation::DeprecationParser;
32use crate::attributes::dummy::DummyParser;
33use crate::attributes::inline::{InlineParser, RustcForceInlineParser};
34use crate::attributes::link_attrs::{
35    ExportStableParser, FfiConstParser, FfiPureParser, LinkNameParser, LinkOrdinalParser,
36    LinkParser, LinkSectionParser, LinkageParser, StdInternalSymbolParser,
37};
38use crate::attributes::lint_helpers::{
39    AsPtrParser, AutomaticallyDerivedParser, PassByValueParser, PubTransparentParser,
40};
41use crate::attributes::loop_match::{ConstContinueParser, LoopMatchParser};
42use crate::attributes::macro_attrs::{
43    AllowInternalUnsafeParser, MacroEscapeParser, MacroUseParser,
44};
45use crate::attributes::must_use::MustUseParser;
46use crate::attributes::no_implicit_prelude::NoImplicitPreludeParser;
47use crate::attributes::non_exhaustive::NonExhaustiveParser;
48use crate::attributes::path::PathParser as PathAttributeParser;
49use crate::attributes::proc_macro_attrs::{
50    ProcMacroAttributeParser, ProcMacroDeriveParser, ProcMacroParser, RustcBuiltinMacroParser,
51};
52use crate::attributes::prototype::CustomMirParser;
53use crate::attributes::repr::{AlignParser, ReprParser};
54use crate::attributes::rustc_internal::{
55    RustcLayoutScalarValidRangeEnd, RustcLayoutScalarValidRangeStart,
56    RustcObjectLifetimeDefaultParser,
57};
58use crate::attributes::semantics::MayDangleParser;
59use crate::attributes::stability::{
60    BodyStabilityParser, ConstStabilityIndirectParser, ConstStabilityParser, StabilityParser,
61};
62use crate::attributes::test_attrs::{IgnoreParser, ShouldPanicParser};
63use crate::attributes::traits::{
64    AllowIncoherentImplParser, CoherenceIsCoreParser, CoinductiveParser, ConstTraitParser,
65    DenyExplicitImplParser, DoNotImplementViaObjectParser, FundamentalParser, MarkerParser,
66    ParenSugarParser, PointeeParser, SkipDuringMethodDispatchParser, SpecializationTraitParser,
67    TypeConstParser, UnsafeSpecializationMarkerParser,
68};
69use crate::attributes::transparency::TransparencyParser;
70use crate::attributes::{AttributeParser as _, Combine, Single, WithoutArgs};
71use crate::parser::{ArgParser, PathParser};
72use crate::session_diagnostics::{AttributeParseError, AttributeParseErrorReason, UnknownMetaItem};
73use crate::target_checking::AllowedTargets;
74
75type GroupType<S> = LazyLock<GroupTypeInner<S>>;
76
77pub(super) struct GroupTypeInner<S: Stage> {
78    pub(super) accepters: BTreeMap<&'static [Symbol], Vec<GroupTypeInnerAccept<S>>>,
79    pub(super) finalizers: Vec<FinalizeFn<S>>,
80}
81
82pub(super) struct GroupTypeInnerAccept<S: Stage> {
83    pub(super) template: AttributeTemplate,
84    pub(super) accept_fn: AcceptFn<S>,
85    pub(super) allowed_targets: AllowedTargets,
86    pub(super) attribute_type: AttributeType,
87}
88
89type AcceptFn<S> =
90    Box<dyn for<'sess, 'a> Fn(&mut AcceptContext<'_, 'sess, S>, &ArgParser<'a>) + Send + Sync>;
91type FinalizeFn<S> =
92    Box<dyn Send + Sync + Fn(&mut FinalizeContext<'_, '_, S>) -> Option<AttributeKind>>;
93
94macro_rules! attribute_parsers {
95    (
96        pub(crate) static $name: ident = [$($names: ty),* $(,)?];
97    ) => {
98        mod early {
99            use super::*;
100            type Combine<T> = super::Combine<T, Early>;
101            type Single<T> = super::Single<T, Early>;
102            type WithoutArgs<T> = super::WithoutArgs<T, Early>;
103
104            attribute_parsers!(@[Early] pub(crate) static $name = [$($names),*];);
105        }
106        mod late {
107            use super::*;
108            type Combine<T> = super::Combine<T, Late>;
109            type Single<T> = super::Single<T, Late>;
110            type WithoutArgs<T> = super::WithoutArgs<T, Late>;
111
112            attribute_parsers!(@[Late] pub(crate) static $name = [$($names),*];);
113        }
114    };
115    (
116        @[$stage: ty] pub(crate) static $name: ident = [$($names: ty),* $(,)?];
117    ) => {
118        pub(crate) static $name: GroupType<$stage> = LazyLock::new(|| {
119            let mut accepts = BTreeMap::<_, Vec<GroupTypeInnerAccept<$stage>>>::new();
120            let mut finalizes = Vec::<FinalizeFn<$stage>>::new();
121            $(
122                {
123                    thread_local! {
124                        static STATE_OBJECT: RefCell<$names> = RefCell::new(<$names>::default());
125                    };
126
127                    for (path, template, accept_fn) in <$names>::ATTRIBUTES {
128                        accepts.entry(*path).or_default().push(GroupTypeInnerAccept {
129                            template: *template,
130                            accept_fn: Box::new(|cx, args| {
131                                STATE_OBJECT.with_borrow_mut(|s| {
132                                    accept_fn(s, cx, args)
133                                })
134                            }),
135                            allowed_targets: <$names as crate::attributes::AttributeParser<$stage>>::ALLOWED_TARGETS,
136                            attribute_type: <$names as crate::attributes::AttributeParser<$stage>>::TYPE,
137                        });
138                    }
139
140                    finalizes.push(Box::new(|cx| {
141                        let state = STATE_OBJECT.take();
142                        state.finalize(cx)
143                    }));
144                }
145            )*
146
147            GroupTypeInner { accepters:accepts, finalizers:finalizes }
148        });
149    };
150}
151attribute_parsers!(
152    pub(crate) static ATTRIBUTE_PARSERS = [
153        // tidy-alphabetical-start
154        AlignParser,
155        BodyStabilityParser,
156        ConfusablesParser,
157        ConstStabilityParser,
158        MacroUseParser,
159        NakedParser,
160        StabilityParser,
161        UsedParser,
162        // tidy-alphabetical-end
163
164        // tidy-alphabetical-start
165        Combine<AllowConstFnUnstableParser>,
166        Combine<AllowInternalUnstableParser>,
167        Combine<ForceTargetFeatureParser>,
168        Combine<LinkParser>,
169        Combine<ReprParser>,
170        Combine<TargetFeatureParser>,
171        Combine<UnstableFeatureBoundParser>,
172        // tidy-alphabetical-end
173
174        // tidy-alphabetical-start
175        Single<CoverageParser>,
176        Single<CrateNameParser>,
177        Single<CustomMirParser>,
178        Single<DeprecationParser>,
179        Single<DummyParser>,
180        Single<ExportNameParser>,
181        Single<IgnoreParser>,
182        Single<InlineParser>,
183        Single<LinkNameParser>,
184        Single<LinkOrdinalParser>,
185        Single<LinkSectionParser>,
186        Single<LinkageParser>,
187        Single<MoveSizeLimitParser>,
188        Single<MustUseParser>,
189        Single<OptimizeParser>,
190        Single<PathAttributeParser>,
191        Single<PatternComplexityLimitParser>,
192        Single<ProcMacroDeriveParser>,
193        Single<RecursionLimitParser>,
194        Single<RustcBuiltinMacroParser>,
195        Single<RustcForceInlineParser>,
196        Single<RustcLayoutScalarValidRangeEnd>,
197        Single<RustcLayoutScalarValidRangeStart>,
198        Single<RustcObjectLifetimeDefaultParser>,
199        Single<SanitizeParser>,
200        Single<ShouldPanicParser>,
201        Single<SkipDuringMethodDispatchParser>,
202        Single<TransparencyParser>,
203        Single<TypeLengthLimitParser>,
204        Single<WithoutArgs<AllowIncoherentImplParser>>,
205        Single<WithoutArgs<AllowInternalUnsafeParser>>,
206        Single<WithoutArgs<AsPtrParser>>,
207        Single<WithoutArgs<AutomaticallyDerivedParser>>,
208        Single<WithoutArgs<CoherenceIsCoreParser>>,
209        Single<WithoutArgs<CoinductiveParser>>,
210        Single<WithoutArgs<ColdParser>>,
211        Single<WithoutArgs<ConstContinueParser>>,
212        Single<WithoutArgs<ConstStabilityIndirectParser>>,
213        Single<WithoutArgs<ConstTraitParser>>,
214        Single<WithoutArgs<CoroutineParser>>,
215        Single<WithoutArgs<DenyExplicitImplParser>>,
216        Single<WithoutArgs<DoNotImplementViaObjectParser>>,
217        Single<WithoutArgs<ExportStableParser>>,
218        Single<WithoutArgs<FfiConstParser>>,
219        Single<WithoutArgs<FfiPureParser>>,
220        Single<WithoutArgs<FundamentalParser>>,
221        Single<WithoutArgs<LoopMatchParser>>,
222        Single<WithoutArgs<MacroEscapeParser>>,
223        Single<WithoutArgs<MarkerParser>>,
224        Single<WithoutArgs<MayDangleParser>>,
225        Single<WithoutArgs<NoImplicitPreludeParser>>,
226        Single<WithoutArgs<NoMangleParser>>,
227        Single<WithoutArgs<NonExhaustiveParser>>,
228        Single<WithoutArgs<ParenSugarParser>>,
229        Single<WithoutArgs<PassByValueParser>>,
230        Single<WithoutArgs<PointeeParser>>,
231        Single<WithoutArgs<ProcMacroAttributeParser>>,
232        Single<WithoutArgs<ProcMacroParser>>,
233        Single<WithoutArgs<PubTransparentParser>>,
234        Single<WithoutArgs<SpecializationTraitParser>>,
235        Single<WithoutArgs<StdInternalSymbolParser>>,
236        Single<WithoutArgs<TrackCallerParser>>,
237        Single<WithoutArgs<TypeConstParser>>,
238        Single<WithoutArgs<UnsafeSpecializationMarkerParser>>,
239        // tidy-alphabetical-end
240    ];
241);
242
243mod private {
244    pub trait Sealed {}
245    impl Sealed for super::Early {}
246    impl Sealed for super::Late {}
247}
248
249// allow because it's a sealed trait
250#[allow(private_interfaces)]
251pub trait Stage: Sized + 'static + Sealed {
252    type Id: Copy;
253
254    fn parsers() -> &'static GroupType<Self>;
255
256    fn emit_err<'sess>(
257        &self,
258        sess: &'sess Session,
259        diag: impl for<'x> Diagnostic<'x>,
260    ) -> ErrorGuaranteed;
261
262    fn should_emit(&self) -> ShouldEmit;
263
264    fn id_is_crate_root(id: Self::Id) -> bool;
265}
266
267// allow because it's a sealed trait
268#[allow(private_interfaces)]
269impl Stage for Early {
270    type Id = NodeId;
271
272    fn parsers() -> &'static GroupType<Self> {
273        &early::ATTRIBUTE_PARSERS
274    }
275    fn emit_err<'sess>(
276        &self,
277        sess: &'sess Session,
278        diag: impl for<'x> Diagnostic<'x>,
279    ) -> ErrorGuaranteed {
280        self.should_emit().emit_err(sess.dcx().create_err(diag))
281    }
282
283    fn should_emit(&self) -> ShouldEmit {
284        self.emit_errors
285    }
286
287    fn id_is_crate_root(id: Self::Id) -> bool {
288        id == CRATE_NODE_ID
289    }
290}
291
292// allow because it's a sealed trait
293#[allow(private_interfaces)]
294impl Stage for Late {
295    type Id = HirId;
296
297    fn parsers() -> &'static GroupType<Self> {
298        &late::ATTRIBUTE_PARSERS
299    }
300    fn emit_err<'sess>(
301        &self,
302        tcx: &'sess Session,
303        diag: impl for<'x> Diagnostic<'x>,
304    ) -> ErrorGuaranteed {
305        tcx.dcx().emit_err(diag)
306    }
307
308    fn should_emit(&self) -> ShouldEmit {
309        ShouldEmit::ErrorsAndLints
310    }
311
312    fn id_is_crate_root(id: Self::Id) -> bool {
313        id == CRATE_HIR_ID
314    }
315}
316
317/// used when parsing attributes for miscellaneous things *before* ast lowering
318pub struct Early {
319    /// Whether to emit errors or delay them as a bug
320    /// For most attributes, the attribute will be parsed again in the `Late` stage and in this case the errors should be delayed
321    /// But for some, such as `cfg`, the attribute will be removed before the `Late` stage so errors must be emitted
322    pub emit_errors: ShouldEmit,
323}
324/// used when parsing attributes during ast lowering
325pub struct Late;
326
327/// Context given to every attribute parser when accepting
328///
329/// Gives [`AttributeParser`]s enough information to create errors, for example.
330pub struct AcceptContext<'f, 'sess, S: Stage> {
331    pub(crate) shared: SharedContext<'f, 'sess, S>,
332    /// The span of the attribute currently being parsed
333    pub(crate) attr_span: Span,
334
335    /// Whether it is an inner or outer attribute
336    pub(crate) attr_style: AttrStyle,
337
338    /// The expected structure of the attribute.
339    ///
340    /// Used in reporting errors to give a hint to users what the attribute *should* look like.
341    pub(crate) template: &'f AttributeTemplate,
342
343    /// The name of the attribute we're currently accepting.
344    pub(crate) attr_path: AttrPath,
345}
346
347impl<'f, 'sess: 'f, S: Stage> SharedContext<'f, 'sess, S> {
348    pub(crate) fn emit_err(&self, diag: impl for<'x> Diagnostic<'x>) -> ErrorGuaranteed {
349        self.stage.emit_err(&self.sess, diag)
350    }
351
352    /// Emit a lint. This method is somewhat special, since lints emitted during attribute parsing
353    /// must be delayed until after HIR is built. This method will take care of the details of
354    /// that.
355    pub(crate) fn emit_lint(&mut self, lint: AttributeLintKind, span: Span) {
356        if !matches!(
357            self.stage.should_emit(),
358            ShouldEmit::ErrorsAndLints | ShouldEmit::EarlyFatal { also_emit_lints: true }
359        ) {
360            return;
361        }
362        let id = self.target_id;
363        (self.emit_lint)(AttributeLint { id, span, kind: lint });
364    }
365
366    pub(crate) fn warn_unused_duplicate(&mut self, used_span: Span, unused_span: Span) {
367        self.emit_lint(
368            AttributeLintKind::UnusedDuplicate {
369                this: unused_span,
370                other: used_span,
371                warning: false,
372            },
373            unused_span,
374        )
375    }
376
377    pub(crate) fn warn_unused_duplicate_future_error(
378        &mut self,
379        used_span: Span,
380        unused_span: Span,
381    ) {
382        self.emit_lint(
383            AttributeLintKind::UnusedDuplicate {
384                this: unused_span,
385                other: used_span,
386                warning: true,
387            },
388            unused_span,
389        )
390    }
391}
392
393impl<'f, 'sess: 'f, S: Stage> AcceptContext<'f, 'sess, S> {
394    pub(crate) fn unknown_key(
395        &self,
396        span: Span,
397        found: String,
398        options: &'static [&'static str],
399    ) -> ErrorGuaranteed {
400        self.emit_err(UnknownMetaItem { span, item: found, expected: options })
401    }
402
403    /// error that a string literal was expected.
404    /// You can optionally give the literal you did find (which you found not to be a string literal)
405    /// which can make better errors. For example, if the literal was a byte string it will suggest
406    /// removing the `b` prefix.
407    pub(crate) fn expected_string_literal(
408        &self,
409        span: Span,
410        actual_literal: Option<&MetaItemLit>,
411    ) -> ErrorGuaranteed {
412        self.emit_err(AttributeParseError {
413            span,
414            attr_span: self.attr_span,
415            template: self.template.clone(),
416            attribute: self.attr_path.clone(),
417            reason: AttributeParseErrorReason::ExpectedStringLiteral {
418                byte_string: actual_literal.and_then(|i| {
419                    i.kind.is_bytestr().then(|| self.sess().source_map().start_point(i.span))
420                }),
421            },
422            attr_style: self.attr_style,
423        })
424    }
425
426    pub(crate) fn expected_integer_literal(&self, span: Span) -> ErrorGuaranteed {
427        self.emit_err(AttributeParseError {
428            span,
429            attr_span: self.attr_span,
430            template: self.template.clone(),
431            attribute: self.attr_path.clone(),
432            reason: AttributeParseErrorReason::ExpectedIntegerLiteral,
433            attr_style: self.attr_style,
434        })
435    }
436
437    pub(crate) fn expected_list(&self, span: Span) -> ErrorGuaranteed {
438        self.emit_err(AttributeParseError {
439            span,
440            attr_span: self.attr_span,
441            template: self.template.clone(),
442            attribute: self.attr_path.clone(),
443            reason: AttributeParseErrorReason::ExpectedList,
444            attr_style: self.attr_style,
445        })
446    }
447
448    pub(crate) fn expected_no_args(&self, args_span: Span) -> ErrorGuaranteed {
449        self.emit_err(AttributeParseError {
450            span: args_span,
451            attr_span: self.attr_span,
452            template: self.template.clone(),
453            attribute: self.attr_path.clone(),
454            reason: AttributeParseErrorReason::ExpectedNoArgs,
455            attr_style: self.attr_style,
456        })
457    }
458
459    /// emit an error that a `name` was expected here
460    pub(crate) fn expected_identifier(&self, span: Span) -> ErrorGuaranteed {
461        self.emit_err(AttributeParseError {
462            span,
463            attr_span: self.attr_span,
464            template: self.template.clone(),
465            attribute: self.attr_path.clone(),
466            reason: AttributeParseErrorReason::ExpectedIdentifier,
467            attr_style: self.attr_style,
468        })
469    }
470
471    /// emit an error that a `name = value` pair was expected at this span. The symbol can be given for
472    /// a nicer error message talking about the specific name that was found lacking a value.
473    pub(crate) fn expected_name_value(&self, span: Span, name: Option<Symbol>) -> ErrorGuaranteed {
474        self.emit_err(AttributeParseError {
475            span,
476            attr_span: self.attr_span,
477            template: self.template.clone(),
478            attribute: self.attr_path.clone(),
479            reason: AttributeParseErrorReason::ExpectedNameValue(name),
480            attr_style: self.attr_style,
481        })
482    }
483
484    /// emit an error that a `name = value` pair was found where that name was already seen.
485    pub(crate) fn duplicate_key(&self, span: Span, key: Symbol) -> ErrorGuaranteed {
486        self.emit_err(AttributeParseError {
487            span,
488            attr_span: self.attr_span,
489            template: self.template.clone(),
490            attribute: self.attr_path.clone(),
491            reason: AttributeParseErrorReason::DuplicateKey(key),
492            attr_style: self.attr_style,
493        })
494    }
495
496    /// an error that should be emitted when a [`MetaItemOrLitParser`](crate::parser::MetaItemOrLitParser)
497    /// was expected *not* to be a literal, but instead a meta item.
498    pub(crate) fn unexpected_literal(&self, span: Span) -> ErrorGuaranteed {
499        self.emit_err(AttributeParseError {
500            span,
501            attr_span: self.attr_span,
502            template: self.template.clone(),
503            attribute: self.attr_path.clone(),
504            reason: AttributeParseErrorReason::UnexpectedLiteral,
505            attr_style: self.attr_style,
506        })
507    }
508
509    pub(crate) fn expected_single_argument(&self, span: Span) -> ErrorGuaranteed {
510        self.emit_err(AttributeParseError {
511            span,
512            attr_span: self.attr_span,
513            template: self.template.clone(),
514            attribute: self.attr_path.clone(),
515            reason: AttributeParseErrorReason::ExpectedSingleArgument,
516            attr_style: self.attr_style,
517        })
518    }
519
520    pub(crate) fn expected_at_least_one_argument(&self, span: Span) -> ErrorGuaranteed {
521        self.emit_err(AttributeParseError {
522            span,
523            attr_span: self.attr_span,
524            template: self.template.clone(),
525            attribute: self.attr_path.clone(),
526            reason: AttributeParseErrorReason::ExpectedAtLeastOneArgument,
527            attr_style: self.attr_style,
528        })
529    }
530
531    /// produces an error along the lines of `expected one of [foo, meow]`
532    pub(crate) fn expected_specific_argument(
533        &self,
534        span: Span,
535        possibilities: &[Symbol],
536    ) -> ErrorGuaranteed {
537        self.emit_err(AttributeParseError {
538            span,
539            attr_span: self.attr_span,
540            template: self.template.clone(),
541            attribute: self.attr_path.clone(),
542            reason: AttributeParseErrorReason::ExpectedSpecificArgument {
543                possibilities,
544                strings: false,
545                list: false,
546            },
547            attr_style: self.attr_style,
548        })
549    }
550
551    /// produces an error along the lines of `expected one of [foo, meow] as an argument`.
552    /// i.e. slightly different wording to [`expected_specific_argument`](Self::expected_specific_argument).
553    pub(crate) fn expected_specific_argument_and_list(
554        &self,
555        span: Span,
556        possibilities: &[Symbol],
557    ) -> ErrorGuaranteed {
558        self.emit_err(AttributeParseError {
559            span,
560            attr_span: self.attr_span,
561            template: self.template.clone(),
562            attribute: self.attr_path.clone(),
563            reason: AttributeParseErrorReason::ExpectedSpecificArgument {
564                possibilities,
565                strings: false,
566                list: true,
567            },
568            attr_style: self.attr_style,
569        })
570    }
571
572    /// produces an error along the lines of `expected one of ["foo", "meow"]`
573    pub(crate) fn expected_specific_argument_strings(
574        &self,
575        span: Span,
576        possibilities: &[Symbol],
577    ) -> ErrorGuaranteed {
578        self.emit_err(AttributeParseError {
579            span,
580            attr_span: self.attr_span,
581            template: self.template.clone(),
582            attribute: self.attr_path.clone(),
583            reason: AttributeParseErrorReason::ExpectedSpecificArgument {
584                possibilities,
585                strings: true,
586                list: false,
587            },
588            attr_style: self.attr_style,
589        })
590    }
591
592    pub(crate) fn warn_empty_attribute(&mut self, span: Span) {
593        self.emit_lint(AttributeLintKind::EmptyAttribute { first_span: span }, span);
594    }
595}
596
597impl<'f, 'sess, S: Stage> Deref for AcceptContext<'f, 'sess, S> {
598    type Target = SharedContext<'f, 'sess, S>;
599
600    fn deref(&self) -> &Self::Target {
601        &self.shared
602    }
603}
604
605impl<'f, 'sess, S: Stage> DerefMut for AcceptContext<'f, 'sess, S> {
606    fn deref_mut(&mut self) -> &mut Self::Target {
607        &mut self.shared
608    }
609}
610
611/// Context given to every attribute parser during finalization.
612///
613/// Gives [`AttributeParser`](crate::attributes::AttributeParser)s enough information to create
614/// errors, for example.
615pub struct SharedContext<'p, 'sess, S: Stage> {
616    /// The parse context, gives access to the session and the
617    /// diagnostics context.
618    pub(crate) cx: &'p mut AttributeParser<'sess, S>,
619    /// The span of the syntactical component this attribute was applied to
620    pub(crate) target_span: Span,
621    /// The id ([`NodeId`] if `S` is `Early`, [`HirId`] if `S` is `Late`) of the syntactical component this attribute was applied to
622    pub(crate) target_id: S::Id,
623
624    pub(crate) emit_lint: &'p mut dyn FnMut(AttributeLint<S::Id>),
625}
626
627/// Context given to every attribute parser during finalization.
628///
629/// Gives [`AttributeParser`](crate::attributes::AttributeParser)s enough information to create
630/// errors, for example.
631pub(crate) struct FinalizeContext<'p, 'sess, S: Stage> {
632    pub(crate) shared: SharedContext<'p, 'sess, S>,
633
634    /// A list of all attribute on this syntax node.
635    ///
636    /// Useful for compatibility checks with other attributes in [`finalize`](crate::attributes::AttributeParser::finalize)
637    ///
638    /// Usually, you should use normal attribute parsing logic instead,
639    /// especially when making a *denylist* of other attributes.
640    pub(crate) all_attrs: &'p [PathParser<'p>],
641}
642
643impl<'p, 'sess: 'p, S: Stage> Deref for FinalizeContext<'p, 'sess, S> {
644    type Target = SharedContext<'p, 'sess, S>;
645
646    fn deref(&self) -> &Self::Target {
647        &self.shared
648    }
649}
650
651impl<'p, 'sess: 'p, S: Stage> DerefMut for FinalizeContext<'p, 'sess, S> {
652    fn deref_mut(&mut self) -> &mut Self::Target {
653        &mut self.shared
654    }
655}
656
657impl<'p, 'sess: 'p, S: Stage> Deref for SharedContext<'p, 'sess, S> {
658    type Target = AttributeParser<'sess, S>;
659
660    fn deref(&self) -> &Self::Target {
661        self.cx
662    }
663}
664
665impl<'p, 'sess: 'p, S: Stage> DerefMut for SharedContext<'p, 'sess, S> {
666    fn deref_mut(&mut self) -> &mut Self::Target {
667        self.cx
668    }
669}
670
671#[derive(PartialEq, Clone, Copy, Debug)]
672pub enum OmitDoc {
673    Lower,
674    Skip,
675}
676
677#[derive(Copy, Clone, Debug)]
678pub enum ShouldEmit {
679    /// The operations will emit errors, and lints, and errors are fatal.
680    ///
681    /// Only relevant when early parsing, in late parsing equivalent to `ErrorsAndLints`.
682    /// Late parsing is never fatal, and instead tries to emit as many diagnostics as possible.
683    EarlyFatal { also_emit_lints: bool },
684    /// The operation will emit errors and lints.
685    /// This is usually what you need.
686    ErrorsAndLints,
687    /// The operation will emit *not* errors and lints.
688    /// Use this if you are *sure* that this operation will be called at a different time with `ShouldEmit::ErrorsAndLints`.
689    Nothing,
690}
691
692impl ShouldEmit {
693    pub(crate) fn emit_err(&self, diag: Diag<'_>) -> ErrorGuaranteed {
694        match self {
695            ShouldEmit::EarlyFatal { .. } if diag.level() == Level::DelayedBug => diag.emit(),
696            ShouldEmit::EarlyFatal { .. } => diag.upgrade_to_fatal().emit(),
697            ShouldEmit::ErrorsAndLints => diag.emit(),
698            ShouldEmit::Nothing => diag.delay_as_bug(),
699        }
700    }
701}
rustc_attr_parsing/context.rs

rustc_attr_parsing/
context.rs
