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

rustdoc/json/
conversions.rs
