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

rustc_attr_parsing/
context.rs
