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