rustdoc/json/
conversions.rs

1//! These from impls are used to create the JSON types which get serialized. They're very close to
2//! the `clean` types but with some fields removed or stringified to simplify the output and not
3//! expose unstable compiler internals.
4
5use rustc_abi::ExternAbi;
6use rustc_ast::ast;
7use rustc_hir as hir;
8use rustc_hir::attrs::{self, DeprecatedSince};
9use rustc_hir::def::CtorKind;
10use rustc_hir::def_id::DefId;
11use rustc_hir::{HeaderSafety, Safety};
12use rustc_metadata::rendered_const;
13use rustc_middle::ty::TyCtxt;
14use rustc_middle::{bug, ty};
15use rustc_span::{Pos, kw, sym};
16use rustdoc_json_types::*;
17use thin_vec::ThinVec;
18
19use crate::clean::{self, ItemId};
20use crate::formats::item_type::ItemType;
21use crate::json::JsonRenderer;
22use crate::passes::collect_intra_doc_links::UrlFragment;
23
24impl JsonRenderer<'_> {
25    pub(super) fn convert_item(&self, item: &clean::Item) -> Option<Item> {
26        let deprecation = item.deprecation(self.tcx);
27        let links = self
28            .cache
29            .intra_doc_links
30            .get(&item.item_id)
31            .into_iter()
32            .flatten()
33            .map(|clean::ItemLink { link, page_id, fragment, .. }| {
34                let id = match fragment {
35                    Some(UrlFragment::Item(frag_id)) => *frag_id,
36                    // FIXME: Pass the `UserWritten` segment to JSON consumer.
37                    Some(UrlFragment::UserWritten(_)) | None => *page_id,
38                };
39
40                (String::from(&**link), self.id_from_item_default(id.into()))
41            })
42            .collect();
43        let docs = item.opt_doc_value();
44        let attrs = item
45            .attrs
46            .other_attrs
47            .iter()
48            .filter_map(|a| maybe_from_hir_attr(a, item.item_id, self.tcx))
49            .collect();
50        let span = item.span(self.tcx);
51        let visibility = item.visibility(self.tcx);
52        let clean::ItemInner { name, item_id, .. } = *item.inner;
53        let id = self.id_from_item(item);
54        let inner = match item.kind {
55            clean::KeywordItem | clean::AttributeItem => return None,
56            clean::StrippedItem(ref inner) => {
57                match &**inner {
58                    // We document stripped modules as with `Module::is_stripped` set to
59                    // `true`, to prevent contained items from being orphaned for downstream users,
60                    // as JSON does no inlining.
61                    clean::ModuleItem(_)
62                        if self.imported_items.contains(&item_id.expect_def_id()) =>
63                    {
64                        from_clean_item(item, self)
65                    }
66                    _ => return None,
67                }
68            }
69            _ => from_clean_item(item, self),
70        };
71        Some(Item {
72            id,
73            crate_id: item_id.krate().as_u32(),
74            name: name.map(|sym| sym.to_string()),
75            span: span.and_then(|span| span.into_json(self)),
76            visibility: visibility.into_json(self),
77            docs,
78            attrs,
79            deprecation: deprecation.into_json(self),
80            inner,
81            links,
82        })
83    }
84
85    fn ids(&self, items: &[clean::Item]) -> Vec<Id> {
86        items
87            .iter()
88            .filter(|i| !i.is_stripped() && !i.is_keyword() && !i.is_attribute())
89            .map(|i| self.id_from_item(i))
90            .collect()
91    }
92
93    fn ids_keeping_stripped(&self, items: &[clean::Item]) -> Vec<Option<Id>> {
94        items
95            .iter()
96            .map(|i| {
97                (!i.is_stripped() && !i.is_keyword() && !i.is_attribute())
98                    .then(|| self.id_from_item(i))
99            })
100            .collect()
101    }
102}
103
104pub(crate) trait FromClean<T> {
105    fn from_clean(f: &T, renderer: &JsonRenderer<'_>) -> Self;
106}
107
108pub(crate) trait IntoJson<T> {
109    fn into_json(&self, renderer: &JsonRenderer<'_>) -> T;
110}
111
112impl<T, U> IntoJson<U> for T
113where
114    U: FromClean<T>,
115{
116    fn into_json(&self, renderer: &JsonRenderer<'_>) -> U {
117        U::from_clean(self, renderer)
118    }
119}
120
121impl<T, U> FromClean<Box<T>> for U
122where
123    U: FromClean<T>,
124{
125    fn from_clean(opt: &Box<T>, renderer: &JsonRenderer<'_>) -> Self {
126        opt.as_ref().into_json(renderer)
127    }
128}
129
130impl<T, U> FromClean<Option<T>> for Option<U>
131where
132    U: FromClean<T>,
133{
134    fn from_clean(opt: &Option<T>, renderer: &JsonRenderer<'_>) -> Self {
135        opt.as_ref().map(|x| x.into_json(renderer))
136    }
137}
138
139impl<T, U> FromClean<Vec<T>> for Vec<U>
140where
141    U: FromClean<T>,
142{
143    fn from_clean(items: &Vec<T>, renderer: &JsonRenderer<'_>) -> Self {
144        items.iter().map(|i| i.into_json(renderer)).collect()
145    }
146}
147
148impl<T, U> FromClean<ThinVec<T>> for Vec<U>
149where
150    U: FromClean<T>,
151{
152    fn from_clean(items: &ThinVec<T>, renderer: &JsonRenderer<'_>) -> Self {
153        items.iter().map(|i| i.into_json(renderer)).collect()
154    }
155}
156
157impl FromClean<clean::Span> for Option<Span> {
158    fn from_clean(span: &clean::Span, renderer: &JsonRenderer<'_>) -> Self {
159        match span.filename(renderer.sess()) {
160            rustc_span::FileName::Real(name) => {
161                if let Some(local_path) = name.into_local_path() {
162                    let hi = span.hi(renderer.sess());
163                    let lo = span.lo(renderer.sess());
164                    Some(Span {
165                        filename: local_path,
166                        begin: (lo.line, lo.col.to_usize() + 1),
167                        end: (hi.line, hi.col.to_usize() + 1),
168                    })
169                } else {
170                    None
171                }
172            }
173            _ => None,
174        }
175    }
176}
177
178impl FromClean<Option<ty::Visibility<DefId>>> for Visibility {
179    fn from_clean(v: &Option<ty::Visibility<DefId>>, renderer: &JsonRenderer<'_>) -> Self {
180        match v {
181            None => Visibility::Default,
182            Some(ty::Visibility::Public) => Visibility::Public,
183            Some(ty::Visibility::Restricted(did)) if did.is_crate_root() => Visibility::Crate,
184            Some(ty::Visibility::Restricted(did)) => Visibility::Restricted {
185                parent: renderer.id_from_item_default((*did).into()),
186                path: renderer.tcx.def_path(*did).to_string_no_crate_verbose(),
187            },
188        }
189    }
190}
191
192impl FromClean<attrs::Deprecation> for Deprecation {
193    fn from_clean(deprecation: &attrs::Deprecation, _renderer: &JsonRenderer<'_>) -> Self {
194        let attrs::Deprecation { since, note, suggestion: _ } = deprecation;
195        let since = match since {
196            DeprecatedSince::RustcVersion(version) => Some(version.to_string()),
197            DeprecatedSince::Future => Some("TBD".to_string()),
198            DeprecatedSince::NonStandard(since) => Some(since.to_string()),
199            DeprecatedSince::Unspecified | DeprecatedSince::Err => None,
200        };
201        Deprecation { since, note: note.map(|sym| sym.to_string()) }
202    }
203}
204
205impl FromClean<clean::GenericArgs> for Option<Box<GenericArgs>> {
206    fn from_clean(generic_args: &clean::GenericArgs, renderer: &JsonRenderer<'_>) -> Self {
207        use clean::GenericArgs::*;
208        match generic_args {
209            AngleBracketed { args, constraints } => {
210                if generic_args.is_empty() {
211                    None
212                } else {
213                    Some(Box::new(GenericArgs::AngleBracketed {
214                        args: args.into_json(renderer),
215                        constraints: constraints.into_json(renderer),
216                    }))
217                }
218            }
219            Parenthesized { inputs, output } => Some(Box::new(GenericArgs::Parenthesized {
220                inputs: inputs.into_json(renderer),
221                output: output.into_json(renderer),
222            })),
223            ReturnTypeNotation => Some(Box::new(GenericArgs::ReturnTypeNotation)),
224        }
225    }
226}
227
228impl FromClean<clean::GenericArg> for GenericArg {
229    fn from_clean(arg: &clean::GenericArg, renderer: &JsonRenderer<'_>) -> Self {
230        use clean::GenericArg::*;
231        match arg {
232            Lifetime(l) => GenericArg::Lifetime(l.into_json(renderer)),
233            Type(t) => GenericArg::Type(t.into_json(renderer)),
234            Const(box c) => GenericArg::Const(c.into_json(renderer)),
235            Infer => GenericArg::Infer,
236        }
237    }
238}
239
240impl FromClean<clean::ConstantKind> for Constant {
241    // FIXME(generic_const_items): Add support for generic const items.
242    fn from_clean(constant: &clean::ConstantKind, renderer: &JsonRenderer<'_>) -> Self {
243        let tcx = renderer.tcx;
244        let expr = constant.expr(tcx);
245        let value = constant.value(tcx);
246        let is_literal = constant.is_literal(tcx);
247        Constant { expr, value, is_literal }
248    }
249}
250
251impl FromClean<clean::AssocItemConstraint> for AssocItemConstraint {
252    fn from_clean(constraint: &clean::AssocItemConstraint, renderer: &JsonRenderer<'_>) -> Self {
253        AssocItemConstraint {
254            name: constraint.assoc.name.to_string(),
255            args: constraint.assoc.args.into_json(renderer),
256            binding: constraint.kind.into_json(renderer),
257        }
258    }
259}
260
261impl FromClean<clean::AssocItemConstraintKind> for AssocItemConstraintKind {
262    fn from_clean(kind: &clean::AssocItemConstraintKind, renderer: &JsonRenderer<'_>) -> Self {
263        use clean::AssocItemConstraintKind::*;
264        match kind {
265            Equality { term } => AssocItemConstraintKind::Equality(term.into_json(renderer)),
266            Bound { bounds } => AssocItemConstraintKind::Constraint(bounds.into_json(renderer)),
267        }
268    }
269}
270
271fn from_clean_item(item: &clean::Item, renderer: &JsonRenderer<'_>) -> ItemEnum {
272    use clean::ItemKind::*;
273    let name = item.name;
274    let is_crate = item.is_crate();
275    let header = item.fn_header(renderer.tcx);
276
277    match &item.inner.kind {
278        ModuleItem(m) => {
279            ItemEnum::Module(Module { is_crate, items: renderer.ids(&m.items), is_stripped: false })
280        }
281        ImportItem(i) => ItemEnum::Use(i.into_json(renderer)),
282        StructItem(s) => ItemEnum::Struct(s.into_json(renderer)),
283        UnionItem(u) => ItemEnum::Union(u.into_json(renderer)),
284        StructFieldItem(f) => ItemEnum::StructField(f.into_json(renderer)),
285        EnumItem(e) => ItemEnum::Enum(e.into_json(renderer)),
286        VariantItem(v) => ItemEnum::Variant(v.into_json(renderer)),
287        FunctionItem(f) => {
288            ItemEnum::Function(from_clean_function(f, true, header.unwrap(), renderer))
289        }
290        ForeignFunctionItem(f, _) => {
291            ItemEnum::Function(from_clean_function(f, false, header.unwrap(), renderer))
292        }
293        TraitItem(t) => ItemEnum::Trait(t.into_json(renderer)),
294        TraitAliasItem(t) => ItemEnum::TraitAlias(t.into_json(renderer)),
295        MethodItem(m, _) => {
296            ItemEnum::Function(from_clean_function(m, true, header.unwrap(), renderer))
297        }
298        RequiredMethodItem(m) => {
299            ItemEnum::Function(from_clean_function(m, false, header.unwrap(), renderer))
300        }
301        ImplItem(i) => ItemEnum::Impl(i.into_json(renderer)),
302        StaticItem(s) => ItemEnum::Static(from_clean_static(s, rustc_hir::Safety::Safe, renderer)),
303        ForeignStaticItem(s, safety) => ItemEnum::Static(from_clean_static(s, *safety, renderer)),
304        ForeignTypeItem => ItemEnum::ExternType,
305        TypeAliasItem(t) => ItemEnum::TypeAlias(t.into_json(renderer)),
306        // FIXME(generic_const_items): Add support for generic free consts
307        ConstantItem(ci) => ItemEnum::Constant {
308            type_: ci.type_.into_json(renderer),
309            const_: ci.kind.into_json(renderer),
310        },
311        MacroItem(m) => ItemEnum::Macro(m.source.clone()),
312        ProcMacroItem(m) => ItemEnum::ProcMacro(m.into_json(renderer)),
313        PrimitiveItem(p) => {
314            ItemEnum::Primitive(Primitive {
315                name: p.as_sym().to_string(),
316                impls: Vec::new(), // Added in JsonRenderer::item
317            })
318        }
319        // FIXME(generic_const_items): Add support for generic associated consts.
320        RequiredAssocConstItem(_generics, ty) => {
321            ItemEnum::AssocConst { type_: ty.into_json(renderer), value: None }
322        }
323        // FIXME(generic_const_items): Add support for generic associated consts.
324        ProvidedAssocConstItem(ci) | ImplAssocConstItem(ci) => ItemEnum::AssocConst {
325            type_: ci.type_.into_json(renderer),
326            value: Some(ci.kind.expr(renderer.tcx)),
327        },
328        RequiredAssocTypeItem(g, b) => ItemEnum::AssocType {
329            generics: g.into_json(renderer),
330            bounds: b.into_json(renderer),
331            type_: None,
332        },
333        AssocTypeItem(t, b) => ItemEnum::AssocType {
334            generics: t.generics.into_json(renderer),
335            bounds: b.into_json(renderer),
336            type_: Some(t.item_type.as_ref().unwrap_or(&t.type_).into_json(renderer)),
337        },
338        // `convert_item` early returns `None` for stripped items, keywords and attributes.
339        KeywordItem | AttributeItem => unreachable!(),
340        StrippedItem(inner) => {
341            match inner.as_ref() {
342                ModuleItem(m) => ItemEnum::Module(Module {
343                    is_crate,
344                    items: renderer.ids(&m.items),
345                    is_stripped: true,
346                }),
347                // `convert_item` early returns `None` for stripped items we're not including
348                _ => unreachable!(),
349            }
350        }
351        ExternCrateItem { src } => ItemEnum::ExternCrate {
352            name: name.as_ref().unwrap().to_string(),
353            rename: src.map(|x| x.to_string()),
354        },
355    }
356}
357
358impl FromClean<clean::Struct> for Struct {
359    fn from_clean(struct_: &clean::Struct, renderer: &JsonRenderer<'_>) -> Self {
360        let has_stripped_fields = struct_.has_stripped_entries();
361        let clean::Struct { ctor_kind, generics, fields } = struct_;
362
363        let kind = match ctor_kind {
364            Some(CtorKind::Fn) => StructKind::Tuple(renderer.ids_keeping_stripped(fields)),
365            Some(CtorKind::Const) => {
366                assert!(fields.is_empty());
367                StructKind::Unit
368            }
369            None => StructKind::Plain { fields: renderer.ids(fields), has_stripped_fields },
370        };
371
372        Struct {
373            kind,
374            generics: generics.into_json(renderer),
375            impls: Vec::new(), // Added in JsonRenderer::item
376        }
377    }
378}
379
380impl FromClean<clean::Union> for Union {
381    fn from_clean(union_: &clean::Union, renderer: &JsonRenderer<'_>) -> Self {
382        let has_stripped_fields = union_.has_stripped_entries();
383        let clean::Union { generics, fields } = union_;
384        Union {
385            generics: generics.into_json(renderer),
386            has_stripped_fields,
387            fields: renderer.ids(fields),
388            impls: Vec::new(), // Added in JsonRenderer::item
389        }
390    }
391}
392
393impl FromClean<rustc_hir::FnHeader> for FunctionHeader {
394    fn from_clean(header: &rustc_hir::FnHeader, renderer: &JsonRenderer<'_>) -> Self {
395        let is_unsafe = match header.safety {
396            HeaderSafety::SafeTargetFeatures => {
397                // The type system's internal implementation details consider
398                // safe functions with the `#[target_feature]` attribute to be analogous
399                // to unsafe functions: `header.is_unsafe()` returns `true` for them.
400                // For rustdoc, this isn't the right decision, so we explicitly return `false`.
401                // Context: https://github.com/rust-lang/rust/issues/142655
402                false
403            }
404            HeaderSafety::Normal(Safety::Safe) => false,
405            HeaderSafety::Normal(Safety::Unsafe) => true,
406        };
407        FunctionHeader {
408            is_async: header.is_async(),
409            is_const: header.is_const(),
410            is_unsafe,
411            abi: header.abi.into_json(renderer),
412        }
413    }
414}
415
416impl FromClean<ExternAbi> for Abi {
417    fn from_clean(a: &ExternAbi, _renderer: &JsonRenderer<'_>) -> Self {
418        match *a {
419            ExternAbi::Rust => Abi::Rust,
420            ExternAbi::C { unwind } => Abi::C { unwind },
421            ExternAbi::Cdecl { unwind } => Abi::Cdecl { unwind },
422            ExternAbi::Stdcall { unwind } => Abi::Stdcall { unwind },
423            ExternAbi::Fastcall { unwind } => Abi::Fastcall { unwind },
424            ExternAbi::Aapcs { unwind } => Abi::Aapcs { unwind },
425            ExternAbi::Win64 { unwind } => Abi::Win64 { unwind },
426            ExternAbi::SysV64 { unwind } => Abi::SysV64 { unwind },
427            ExternAbi::System { unwind } => Abi::System { unwind },
428            _ => Abi::Other(a.to_string()),
429        }
430    }
431}
432
433impl FromClean<clean::Lifetime> for String {
434    fn from_clean(l: &clean::Lifetime, _renderer: &JsonRenderer<'_>) -> String {
435        l.0.to_string()
436    }
437}
438
439impl FromClean<clean::Generics> for Generics {
440    fn from_clean(generics: &clean::Generics, renderer: &JsonRenderer<'_>) -> Self {
441        Generics {
442            params: generics.params.into_json(renderer),
443            where_predicates: generics.where_predicates.into_json(renderer),
444        }
445    }
446}
447
448impl FromClean<clean::GenericParamDef> for GenericParamDef {
449    fn from_clean(generic_param: &clean::GenericParamDef, renderer: &JsonRenderer<'_>) -> Self {
450        GenericParamDef {
451            name: generic_param.name.to_string(),
452            kind: generic_param.kind.into_json(renderer),
453        }
454    }
455}
456
457impl FromClean<clean::GenericParamDefKind> for GenericParamDefKind {
458    fn from_clean(kind: &clean::GenericParamDefKind, renderer: &JsonRenderer<'_>) -> Self {
459        use clean::GenericParamDefKind::*;
460        match kind {
461            Lifetime { outlives } => {
462                GenericParamDefKind::Lifetime { outlives: outlives.into_json(renderer) }
463            }
464            Type { bounds, default, synthetic } => GenericParamDefKind::Type {
465                bounds: bounds.into_json(renderer),
466                default: default.into_json(renderer),
467                is_synthetic: *synthetic,
468            },
469            Const { ty, default } => GenericParamDefKind::Const {
470                type_: ty.into_json(renderer),
471                default: default.as_ref().map(|x| x.as_ref().clone()),
472            },
473        }
474    }
475}
476
477impl FromClean<clean::WherePredicate> for WherePredicate {
478    fn from_clean(predicate: &clean::WherePredicate, renderer: &JsonRenderer<'_>) -> Self {
479        use clean::WherePredicate::*;
480        match predicate {
481            BoundPredicate { ty, bounds, bound_params } => WherePredicate::BoundPredicate {
482                type_: ty.into_json(renderer),
483                bounds: bounds.into_json(renderer),
484                generic_params: bound_params.into_json(renderer),
485            },
486            RegionPredicate { lifetime, bounds } => WherePredicate::LifetimePredicate {
487                lifetime: lifetime.into_json(renderer),
488                outlives: bounds
489                    .iter()
490                    .map(|bound| match bound {
491                        clean::GenericBound::Outlives(lt) => lt.into_json(renderer),
492                        _ => bug!("found non-outlives-bound on lifetime predicate"),
493                    })
494                    .collect(),
495            },
496            EqPredicate { lhs, rhs } => WherePredicate::EqPredicate {
497                // The LHS currently has type `Type` but it should be a `QualifiedPath` since it may
498                // refer to an associated const. However, `EqPredicate` shouldn't exist in the first
499                // place: <https://github.com/rust-lang/rust/141368>.
500                lhs: lhs.into_json(renderer),
501                rhs: rhs.into_json(renderer),
502            },
503        }
504    }
505}
506
507impl FromClean<clean::GenericBound> for GenericBound {
508    fn from_clean(bound: &clean::GenericBound, renderer: &JsonRenderer<'_>) -> Self {
509        use clean::GenericBound::*;
510        match bound {
511            TraitBound(clean::PolyTrait { trait_, generic_params }, modifier) => {
512                GenericBound::TraitBound {
513                    trait_: trait_.into_json(renderer),
514                    generic_params: generic_params.into_json(renderer),
515                    modifier: modifier.into_json(renderer),
516                }
517            }
518            Outlives(lifetime) => GenericBound::Outlives(lifetime.into_json(renderer)),
519            Use(args) => GenericBound::Use(
520                args.iter()
521                    .map(|arg| match arg {
522                        clean::PreciseCapturingArg::Lifetime(lt) => {
523                            PreciseCapturingArg::Lifetime(lt.into_json(renderer))
524                        }
525                        clean::PreciseCapturingArg::Param(param) => {
526                            PreciseCapturingArg::Param(param.to_string())
527                        }
528                    })
529                    .collect(),
530            ),
531        }
532    }
533}
534
535impl FromClean<rustc_hir::TraitBoundModifiers> for TraitBoundModifier {
536    fn from_clean(
537        modifiers: &rustc_hir::TraitBoundModifiers,
538        _renderer: &JsonRenderer<'_>,
539    ) -> Self {
540        use rustc_hir as hir;
541        let hir::TraitBoundModifiers { constness, polarity } = modifiers;
542        match (constness, polarity) {
543            (hir::BoundConstness::Never, hir::BoundPolarity::Positive) => TraitBoundModifier::None,
544            (hir::BoundConstness::Never, hir::BoundPolarity::Maybe(_)) => TraitBoundModifier::Maybe,
545            (hir::BoundConstness::Maybe(_), hir::BoundPolarity::Positive) => {
546                TraitBoundModifier::MaybeConst
547            }
548            // FIXME: Fill out the rest of this matrix.
549            _ => TraitBoundModifier::None,
550        }
551    }
552}
553
554impl FromClean<clean::Type> for Type {
555    fn from_clean(ty: &clean::Type, renderer: &JsonRenderer<'_>) -> Self {
556        use clean::Type::{
557            Array, BareFunction, BorrowedRef, Generic, ImplTrait, Infer, Primitive, QPath,
558            RawPointer, SelfTy, Slice, Tuple, UnsafeBinder,
559        };
560
561        match ty {
562            clean::Type::Path { path } => Type::ResolvedPath(path.into_json(renderer)),
563            clean::Type::DynTrait(bounds, lt) => Type::DynTrait(DynTrait {
564                lifetime: lt.into_json(renderer),
565                traits: bounds.into_json(renderer),
566            }),
567            Generic(s) => Type::Generic(s.to_string()),
568            // FIXME: add dedicated variant to json Type?
569            SelfTy => Type::Generic("Self".to_owned()),
570            Primitive(p) => Type::Primitive(p.as_sym().to_string()),
571            BareFunction(f) => Type::FunctionPointer(Box::new(f.into_json(renderer))),
572            Tuple(t) => Type::Tuple(t.into_json(renderer)),
573            Slice(t) => Type::Slice(Box::new(t.into_json(renderer))),
574            Array(t, s) => {
575                Type::Array { type_: Box::new(t.into_json(renderer)), len: s.to_string() }
576            }
577            clean::Type::Pat(t, p) => Type::Pat {
578                type_: Box::new(t.into_json(renderer)),
579                __pat_unstable_do_not_use: p.to_string(),
580            },
581            ImplTrait(g) => Type::ImplTrait(g.into_json(renderer)),
582            Infer => Type::Infer,
583            RawPointer(mutability, type_) => Type::RawPointer {
584                is_mutable: *mutability == ast::Mutability::Mut,
585                type_: Box::new(type_.into_json(renderer)),
586            },
587            BorrowedRef { lifetime, mutability, type_ } => Type::BorrowedRef {
588                lifetime: lifetime.into_json(renderer),
589                is_mutable: *mutability == ast::Mutability::Mut,
590                type_: Box::new(type_.into_json(renderer)),
591            },
592            QPath(qpath) => qpath.into_json(renderer),
593            // FIXME(unsafe_binder): Implement rustdoc-json.
594            UnsafeBinder(_) => todo!(),
595        }
596    }
597}
598
599impl FromClean<clean::Path> for Path {
600    fn from_clean(path: &clean::Path, renderer: &JsonRenderer<'_>) -> Self {
601        Path {
602            path: path.whole_name(),
603            id: renderer.id_from_item_default(path.def_id().into()),
604            args: {
605                if let Some((final_seg, rest_segs)) = path.segments.split_last() {
606                    // In general, `clean::Path` can hold things like
607                    // `std::vec::Vec::<u32>::new`, where generic args appear
608                    // in a middle segment. But for the places where `Path` is
609                    // used by rustdoc-json-types, generic args can only be
610                    // used in the final segment, e.g. `std::vec::Vec<u32>`. So
611                    // check that the non-final segments have no generic args.
612                    assert!(rest_segs.iter().all(|seg| seg.args.is_empty()));
613                    final_seg.args.into_json(renderer)
614                } else {
615                    None // no generics on any segments because there are no segments
616                }
617            },
618        }
619    }
620}
621
622impl FromClean<clean::QPathData> for Type {
623    fn from_clean(qpath: &clean::QPathData, renderer: &JsonRenderer<'_>) -> Self {
624        let clean::QPathData { assoc, self_type, should_fully_qualify: _, trait_ } = qpath;
625
626        Self::QualifiedPath {
627            name: assoc.name.to_string(),
628            args: assoc.args.into_json(renderer),
629            self_type: Box::new(self_type.into_json(renderer)),
630            trait_: trait_.into_json(renderer),
631        }
632    }
633}
634
635impl FromClean<clean::Term> for Term {
636    fn from_clean(term: &clean::Term, renderer: &JsonRenderer<'_>) -> Self {
637        match term {
638            clean::Term::Type(ty) => Term::Type(ty.into_json(renderer)),
639            clean::Term::Constant(c) => Term::Constant(c.into_json(renderer)),
640        }
641    }
642}
643
644impl FromClean<clean::BareFunctionDecl> for FunctionPointer {
645    fn from_clean(bare_decl: &clean::BareFunctionDecl, renderer: &JsonRenderer<'_>) -> Self {
646        let clean::BareFunctionDecl { safety, generic_params, decl, abi } = bare_decl;
647        FunctionPointer {
648            header: FunctionHeader {
649                is_unsafe: safety.is_unsafe(),
650                is_const: false,
651                is_async: false,
652                abi: abi.into_json(renderer),
653            },
654            generic_params: generic_params.into_json(renderer),
655            sig: decl.into_json(renderer),
656        }
657    }
658}
659
660impl FromClean<clean::FnDecl> for FunctionSignature {
661    fn from_clean(decl: &clean::FnDecl, renderer: &JsonRenderer<'_>) -> Self {
662        let clean::FnDecl { inputs, output, c_variadic } = decl;
663        FunctionSignature {
664            inputs: inputs
665                .iter()
666                .map(|param| {
667                    // `_` is the most sensible name for missing param names.
668                    let name = param.name.unwrap_or(kw::Underscore).to_string();
669                    let type_ = param.type_.into_json(renderer);
670                    (name, type_)
671                })
672                .collect(),
673            output: if output.is_unit() { None } else { Some(output.into_json(renderer)) },
674            is_c_variadic: *c_variadic,
675        }
676    }
677}
678
679impl FromClean<clean::Trait> for Trait {
680    fn from_clean(trait_: &clean::Trait, renderer: &JsonRenderer<'_>) -> Self {
681        let tcx = renderer.tcx;
682        let is_auto = trait_.is_auto(tcx);
683        let is_unsafe = trait_.safety(tcx).is_unsafe();
684        let is_dyn_compatible = trait_.is_dyn_compatible(tcx);
685        let clean::Trait { items, generics, bounds, .. } = trait_;
686        Trait {
687            is_auto,
688            is_unsafe,
689            is_dyn_compatible,
690            items: renderer.ids(items),
691            generics: generics.into_json(renderer),
692            bounds: bounds.into_json(renderer),
693            implementations: Vec::new(), // Added in JsonRenderer::item
694        }
695    }
696}
697
698impl FromClean<clean::PolyTrait> for PolyTrait {
699    fn from_clean(
700        clean::PolyTrait { trait_, generic_params }: &clean::PolyTrait,
701        renderer: &JsonRenderer<'_>,
702    ) -> Self {
703        PolyTrait {
704            trait_: trait_.into_json(renderer),
705            generic_params: generic_params.into_json(renderer),
706        }
707    }
708}
709
710impl FromClean<clean::Impl> for Impl {
711    fn from_clean(impl_: &clean::Impl, renderer: &JsonRenderer<'_>) -> Self {
712        let provided_trait_methods = impl_.provided_trait_methods(renderer.tcx);
713        let clean::Impl { safety, generics, trait_, for_, items, polarity, kind } = impl_;
714        // FIXME: use something like ImplKind in JSON?
715        let (is_synthetic, blanket_impl) = match kind {
716            clean::ImplKind::Normal | clean::ImplKind::FakeVariadic => (false, None),
717            clean::ImplKind::Auto => (true, None),
718            clean::ImplKind::Blanket(ty) => (false, Some(ty)),
719        };
720        let is_negative = match polarity {
721            ty::ImplPolarity::Positive | ty::ImplPolarity::Reservation => false,
722            ty::ImplPolarity::Negative => true,
723        };
724        Impl {
725            is_unsafe: safety.is_unsafe(),
726            generics: generics.into_json(renderer),
727            provided_trait_methods: provided_trait_methods
728                .into_iter()
729                .map(|x| x.to_string())
730                .collect(),
731            trait_: trait_.into_json(renderer),
732            for_: for_.into_json(renderer),
733            items: renderer.ids(items),
734            is_negative,
735            is_synthetic,
736            blanket_impl: blanket_impl.map(|x| x.into_json(renderer)),
737        }
738    }
739}
740
741pub(crate) fn from_clean_function(
742    clean::Function { decl, generics }: &clean::Function,
743    has_body: bool,
744    header: rustc_hir::FnHeader,
745    renderer: &JsonRenderer<'_>,
746) -> Function {
747    Function {
748        sig: decl.into_json(renderer),
749        generics: generics.into_json(renderer),
750        header: header.into_json(renderer),
751        has_body,
752    }
753}
754
755impl FromClean<clean::Enum> for Enum {
756    fn from_clean(enum_: &clean::Enum, renderer: &JsonRenderer<'_>) -> Self {
757        let has_stripped_variants = enum_.has_stripped_entries();
758        let clean::Enum { variants, generics } = enum_;
759        Enum {
760            generics: generics.into_json(renderer),
761            has_stripped_variants,
762            variants: renderer.ids(&variants.as_slice().raw),
763            impls: Vec::new(), // Added in JsonRenderer::item
764        }
765    }
766}
767
768impl FromClean<clean::Variant> for Variant {
769    fn from_clean(variant: &clean::Variant, renderer: &JsonRenderer<'_>) -> Self {
770        use clean::VariantKind::*;
771
772        let discriminant = variant.discriminant.into_json(renderer);
773
774        let kind = match &variant.kind {
775            CLike => VariantKind::Plain,
776            Tuple(fields) => VariantKind::Tuple(renderer.ids_keeping_stripped(fields)),
777            Struct(s) => VariantKind::Struct {
778                has_stripped_fields: s.has_stripped_entries(),
779                fields: renderer.ids(&s.fields),
780            },
781        };
782
783        Variant { kind, discriminant }
784    }
785}
786
787impl FromClean<clean::Discriminant> for Discriminant {
788    fn from_clean(disr: &clean::Discriminant, renderer: &JsonRenderer<'_>) -> Self {
789        let tcx = renderer.tcx;
790        Discriminant {
791            // expr is only none if going through the inlining path, which gets
792            // `rustc_middle` types, not `rustc_hir`, but because JSON never inlines
793            // the expr is always some.
794            expr: disr.expr(tcx).unwrap(),
795            value: disr.value(tcx, false),
796        }
797    }
798}
799
800impl FromClean<clean::Import> for Use {
801    fn from_clean(import: &clean::Import, renderer: &JsonRenderer<'_>) -> Self {
802        use clean::ImportKind::*;
803        let (name, is_glob) = match import.kind {
804            Simple(s) => (s.to_string(), false),
805            Glob => (import.source.path.last_opt().unwrap_or(sym::asterisk).to_string(), true),
806        };
807        Use {
808            source: import.source.path.whole_name(),
809            name,
810            id: import.source.did.map(ItemId::from).map(|i| renderer.id_from_item_default(i)),
811            is_glob,
812        }
813    }
814}
815
816impl FromClean<clean::ProcMacro> for ProcMacro {
817    fn from_clean(mac: &clean::ProcMacro, renderer: &JsonRenderer<'_>) -> Self {
818        ProcMacro {
819            kind: mac.kind.into_json(renderer),
820            helpers: mac.helpers.iter().map(|x| x.to_string()).collect(),
821        }
822    }
823}
824
825impl FromClean<rustc_span::hygiene::MacroKind> for MacroKind {
826    fn from_clean(kind: &rustc_span::hygiene::MacroKind, _renderer: &JsonRenderer<'_>) -> Self {
827        use rustc_span::hygiene::MacroKind::*;
828        match kind {
829            Bang => MacroKind::Bang,
830            Attr => MacroKind::Attr,
831            Derive => MacroKind::Derive,
832        }
833    }
834}
835
836impl FromClean<clean::TypeAlias> for TypeAlias {
837    fn from_clean(type_alias: &clean::TypeAlias, renderer: &JsonRenderer<'_>) -> Self {
838        let clean::TypeAlias { type_, generics, item_type: _, inner_type: _ } = type_alias;
839        TypeAlias { type_: type_.into_json(renderer), generics: generics.into_json(renderer) }
840    }
841}
842
843fn from_clean_static(
844    stat: &clean::Static,
845    safety: rustc_hir::Safety,
846    renderer: &JsonRenderer<'_>,
847) -> Static {
848    let tcx = renderer.tcx;
849    Static {
850        type_: stat.type_.as_ref().into_json(renderer),
851        is_mutable: stat.mutability == ast::Mutability::Mut,
852        is_unsafe: safety.is_unsafe(),
853        expr: stat
854            .expr
855            .map(|e| rendered_const(tcx, tcx.hir_body(e), tcx.hir_body_owner_def_id(e)))
856            .unwrap_or_default(),
857    }
858}
859
860impl FromClean<clean::TraitAlias> for TraitAlias {
861    fn from_clean(alias: &clean::TraitAlias, renderer: &JsonRenderer<'_>) -> Self {
862        TraitAlias {
863            generics: alias.generics.into_json(renderer),
864            params: alias.bounds.into_json(renderer),
865        }
866    }
867}
868
869impl FromClean<ItemType> for ItemKind {
870    fn from_clean(kind: &ItemType, _renderer: &JsonRenderer<'_>) -> Self {
871        use ItemType::*;
872        match kind {
873            Module => ItemKind::Module,
874            ExternCrate => ItemKind::ExternCrate,
875            Import => ItemKind::Use,
876            Struct => ItemKind::Struct,
877            Union => ItemKind::Union,
878            Enum => ItemKind::Enum,
879            Function | TyMethod | Method => ItemKind::Function,
880            TypeAlias => ItemKind::TypeAlias,
881            Static => ItemKind::Static,
882            Constant => ItemKind::Constant,
883            Trait => ItemKind::Trait,
884            Impl => ItemKind::Impl,
885            StructField => ItemKind::StructField,
886            Variant => ItemKind::Variant,
887            Macro => ItemKind::Macro,
888            Primitive => ItemKind::Primitive,
889            AssocConst => ItemKind::AssocConst,
890            AssocType => ItemKind::AssocType,
891            ForeignType => ItemKind::ExternType,
892            Keyword => ItemKind::Keyword,
893            Attribute => ItemKind::Attribute,
894            TraitAlias => ItemKind::TraitAlias,
895            ProcAttribute => ItemKind::ProcAttribute,
896            ProcDerive => ItemKind::ProcDerive,
897        }
898    }
899}
900
901/// Maybe convert a attribute from hir to json.
902///
903/// Returns `None` if the attribute shouldn't be in the output.
904fn maybe_from_hir_attr(
905    attr: &hir::Attribute,
906    item_id: ItemId,
907    tcx: TyCtxt<'_>,
908) -> Option<Attribute> {
909    use attrs::AttributeKind as AK;
910
911    let kind = match attr {
912        hir::Attribute::Parsed(kind) => kind,
913
914        hir::Attribute::Unparsed(_) => {
915            return Some(if attr.has_name(sym::macro_export) {
916                Attribute::MacroExport
917                // FIXME: We should handle `#[doc(hidden)]`.
918            } else {
919                other_attr(tcx, attr)
920            });
921        }
922    };
923
924    Some(match kind {
925        AK::Deprecation { .. } => return None, // Handled separately into Item::deprecation.
926        AK::DocComment { .. } => unreachable!("doc comments stripped out earlier"),
927
928        AK::MustUse { reason, span: _ } => {
929            Attribute::MustUse { reason: reason.map(|s| s.to_string()) }
930        }
931        AK::Repr { .. } => repr_attr(
932            tcx,
933            item_id.as_def_id().expect("all items that could have #[repr] have a DefId"),
934        ),
935        AK::ExportName { name, span: _ } => Attribute::ExportName(name.to_string()),
936        AK::LinkSection { name, span: _ } => Attribute::LinkSection(name.to_string()),
937        AK::TargetFeature { features, .. } => Attribute::TargetFeature {
938            enable: features.iter().map(|(feat, _span)| feat.to_string()).collect(),
939        },
940
941        AK::NoMangle(_) => Attribute::NoMangle,
942        AK::NonExhaustive(_) => Attribute::NonExhaustive,
943        AK::AutomaticallyDerived(_) => Attribute::AutomaticallyDerived,
944
945        _ => other_attr(tcx, attr),
946    })
947}
948
949fn other_attr(tcx: TyCtxt<'_>, attr: &hir::Attribute) -> Attribute {
950    let mut s = rustc_hir_pretty::attribute_to_string(&tcx, attr);
951    assert_eq!(s.pop(), Some('\n'));
952    Attribute::Other(s)
953}
954
955fn repr_attr(tcx: TyCtxt<'_>, def_id: DefId) -> Attribute {
956    let repr = tcx.adt_def(def_id).repr();
957
958    let kind = if repr.c() {
959        ReprKind::C
960    } else if repr.transparent() {
961        ReprKind::Transparent
962    } else if repr.simd() {
963        ReprKind::Simd
964    } else {
965        ReprKind::Rust
966    };
967
968    let align = repr.align.map(|a| a.bytes());
969    let packed = repr.pack.map(|p| p.bytes());
970    let int = repr.int.map(format_integer_type);
971
972    Attribute::Repr(AttributeRepr { kind, align, packed, int })
973}
974
975fn format_integer_type(it: rustc_abi::IntegerType) -> String {
976    use rustc_abi::Integer::*;
977    use rustc_abi::IntegerType::*;
978    match it {
979        Pointer(true) => "isize",
980        Pointer(false) => "usize",
981        Fixed(I8, true) => "i8",
982        Fixed(I8, false) => "u8",
983        Fixed(I16, true) => "i16",
984        Fixed(I16, false) => "u16",
985        Fixed(I32, true) => "i32",
986        Fixed(I32, false) => "u32",
987        Fixed(I64, true) => "i64",
988        Fixed(I64, false) => "u64",
989        Fixed(I128, true) => "i128",
990        Fixed(I128, false) => "u128",
991    }
992    .to_owned()
993}
rustdoc/json/conversions.rs

rustdoc/json/
conversions.rs
