rustdoc_types/
lib.rs

1//! Rustdoc's JSON output interface
2//!
3//! These types are the public API exposed through the `--output-format json` flag. The [`Crate`]
4//! struct is the root of the JSON blob and all other items are contained within.
5//!
6//! We expose a `rustc-hash` feature that is disabled by default. This feature switches the
7//! [`std::collections::HashMap`] for [`rustc_hash::FxHashMap`] to improve the performance of said
8//! `HashMap` in specific situations.
9//!
10//! `cargo-semver-checks` for example, saw a [-3% improvement][1] when benchmarking using the
11//! `aws_sdk_ec2` JSON output (~500MB of JSON). As always, we recommend measuring the impact before
12//! turning this feature on, as [`FxHashMap`][2] only concerns itself with hash speed, and may
13//! increase the number of collisions.
14//!
15//! [1]: https://rust-lang.zulipchat.com/#narrow/channel/266220-t-rustdoc/topic/rustc-hash.20and.20performance.20of.20rustdoc-types/near/474855731
16//! [2]: https://crates.io/crates/rustc-hash
17
18#[cfg(not(feature = "rustc-hash"))]
19use std::collections::HashMap;
20use std::path::PathBuf;
21
22#[cfg(feature = "rustc-hash")]
23use rustc_hash::FxHashMap as HashMap;
24use serde::{Deserialize, Serialize};
25
26
27/// The version of JSON output that this crate represents.
28///
29/// This integer is incremented with every breaking change to the API,
30/// and is returned along with the JSON blob as [`Crate::format_version`].
31/// Consuming code should assert that this value matches the format version(s) that it supports.
32pub const FORMAT_VERSION: u32 = 43;
33
34/// The root of the emitted JSON blob.
35///
36/// It contains all type/documentation information
37/// about the language items in the local crate, as well as info about external items to allow
38/// tools to find or link to them.
39#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
40pub struct Crate {
41    /// The id of the root [`Module`] item of the local crate.
42    pub root: Id,
43    /// The version string given to `--crate-version`, if any.
44    pub crate_version: Option<String>,
45    /// Whether or not the output includes private items.
46    pub includes_private: bool,
47    /// A collection of all items in the local crate as well as some external traits and their
48    /// items that are referenced locally.
49    pub index: HashMap<Id, Item>,
50    /// Maps IDs to fully qualified paths and other info helpful for generating links.
51    pub paths: HashMap<Id, ItemSummary>,
52    /// Maps `crate_id` of items to a crate name and html_root_url if it exists.
53    pub external_crates: HashMap<u32, ExternalCrate>,
54    /// A single version number to be used in the future when making backwards incompatible changes
55    /// to the JSON output.
56    pub format_version: u32,
57}
58
59/// Metadata of a crate, either the same crate on which `rustdoc` was invoked, or its dependency.
60#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
61pub struct ExternalCrate {
62    /// The name of the crate.
63    ///
64    /// Note: This is the [*crate* name][crate-name], which may not be the same as the
65    /// [*package* name][package-name]. For example, for <https://crates.io/crates/regex-syntax>,
66    /// this field will be `regex_syntax` (which uses an `_`, not a `-`).
67    ///
68    /// [crate-name]: https://doc.rust-lang.org/stable/cargo/reference/cargo-targets.html#the-name-field
69    /// [package-name]: https://doc.rust-lang.org/stable/cargo/reference/manifest.html#the-name-field
70    pub name: String,
71    /// The root URL at which the crate's documentation lives.
72    pub html_root_url: Option<String>,
73}
74
75/// Information about an external (not defined in the local crate) [`Item`].
76///
77/// For external items, you don't get the same level of
78/// information. This struct should contain enough to generate a link/reference to the item in
79/// question, or can be used by a tool that takes the json output of multiple crates to find
80/// the actual item definition with all the relevant info.
81#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
82pub struct ItemSummary {
83    /// Can be used to look up the name and html_root_url of the crate this item came from in the
84    /// `external_crates` map.
85    pub crate_id: u32,
86    /// The list of path components for the fully qualified path of this item (e.g.
87    /// `["std", "io", "lazy", "Lazy"]` for `std::io::lazy::Lazy`).
88    ///
89    /// Note that items can appear in multiple paths, and the one chosen is implementation
90    /// defined. Currently, this is the full path to where the item was defined. Eg
91    /// [`String`] is currently `["alloc", "string", "String"]` and [`HashMap`][`std::collections::HashMap`]
92    /// is `["std", "collections", "hash", "map", "HashMap"]`, but this is subject to change.
93    pub path: Vec<String>,
94    /// Whether this item is a struct, trait, macro, etc.
95    pub kind: ItemKind,
96}
97
98/// Anything that can hold documentation - modules, structs, enums, functions, traits, etc.
99///
100/// The `Item` data type holds fields that can apply to any of these,
101/// and leaves kind-specific details (like function args or enum variants) to the `inner` field.
102#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
103pub struct Item {
104    /// The unique identifier of this item. Can be used to find this item in various mappings.
105    pub id: Id,
106    /// This can be used as a key to the `external_crates` map of [`Crate`] to see which crate
107    /// this item came from.
108    pub crate_id: u32,
109    /// Some items such as impls don't have names.
110    pub name: Option<String>,
111    /// The source location of this item (absent if it came from a macro expansion or inline
112    /// assembly).
113    pub span: Option<Span>,
114    /// By default all documented items are public, but you can tell rustdoc to output private items
115    /// so this field is needed to differentiate.
116    pub visibility: Visibility,
117    /// The full markdown docstring of this item. Absent if there is no documentation at all,
118    /// Some("") if there is some documentation but it is empty (EG `#[doc = ""]`).
119    pub docs: Option<String>,
120    /// This mapping resolves [intra-doc links](https://github.com/rust-lang/rfcs/blob/master/text/1946-intra-rustdoc-links.md) from the docstring to their IDs
121    pub links: HashMap<String, Id>,
122    /// Attributes on this item.
123    ///
124    /// Does not include `#[deprecated]` attributes: see the [`Self::deprecation`] field instead.
125    ///
126    /// Some attributes appear in pretty-printed Rust form, regardless of their formatting
127    /// in the original source code. For example:
128    /// - `#[non_exhaustive]` and `#[must_use]` are represented as themselves.
129    /// - `#[no_mangle]` and `#[export_name]` are also represented as themselves.
130    /// - `#[repr(C)]` and other reprs also appear as themselves,
131    ///   though potentially with a different order: e.g. `repr(i8, C)` may become `repr(C, i8)`.
132    ///   Multiple repr attributes on the same item may be combined into an equivalent single attr.
133    ///
134    /// Other attributes may appear debug-printed. For example:
135    /// - `#[inline]` becomes something similar to `#[attr="Inline(Hint)"]`.
136    ///
137    /// As an internal implementation detail subject to change, this debug-printing format
138    /// is currently equivalent to the HIR pretty-printing of parsed attributes.
139    pub attrs: Vec<String>,
140    /// Information about the item’s deprecation, if present.
141    pub deprecation: Option<Deprecation>,
142    /// The type-specific fields describing this item.
143    pub inner: ItemEnum,
144}
145
146/// A range of source code.
147#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
148pub struct Span {
149    /// The path to the source file for this span relative to the path `rustdoc` was invoked with.
150    pub filename: PathBuf,
151    /// Zero indexed Line and Column of the first character of the `Span`
152    pub begin: (usize, usize),
153    /// Zero indexed Line and Column of the last character of the `Span`
154    pub end: (usize, usize),
155}
156
157/// Information about the deprecation of an [`Item`].
158#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
159pub struct Deprecation {
160    /// Usually a version number when this [`Item`] first became deprecated.
161    pub since: Option<String>,
162    /// The reason for deprecation and/or what alternatives to use.
163    pub note: Option<String>,
164}
165
166/// Visibility of an [`Item`].
167#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
168#[serde(rename_all = "snake_case")]
169pub enum Visibility {
170    /// Explicitly public visibility set with `pub`.
171    Public,
172    /// For the most part items are private by default. The exceptions are associated items of
173    /// public traits and variants of public enums.
174    Default,
175    /// Explicitly crate-wide visibility set with `pub(crate)`
176    Crate,
177    /// For `pub(in path)` visibility.
178    Restricted {
179        /// ID of the module to which this visibility restricts items.
180        parent: Id,
181        /// The path with which [`parent`] was referenced
182        /// (like `super::super` or `crate::foo::bar`).
183        ///
184        /// [`parent`]: Visibility::Restricted::parent
185        path: String,
186    },
187}
188
189/// Dynamic trait object type (`dyn Trait`).
190#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
191pub struct DynTrait {
192    /// All the traits implemented. One of them is the vtable, and the rest must be auto traits.
193    pub traits: Vec<PolyTrait>,
194    /// The lifetime of the whole dyn object
195    /// ```text
196    /// dyn Debug + 'static
197    ///             ^^^^^^^
198    ///             |
199    ///             this part
200    /// ```
201    pub lifetime: Option<String>,
202}
203
204/// A trait and potential HRTBs
205#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
206pub struct PolyTrait {
207    /// The path to the trait.
208    #[serde(rename = "trait")]
209    pub trait_: Path,
210    /// Used for Higher-Rank Trait Bounds (HRTBs)
211    /// ```text
212    /// dyn for<'a> Fn() -> &'a i32"
213    ///     ^^^^^^^
214    /// ```
215    pub generic_params: Vec<GenericParamDef>,
216}
217
218/// A set of generic arguments provided to a path segment, e.g.
219///
220/// ```text
221/// std::option::Option::<u32>::None
222///                      ^^^^^
223/// ```
224#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
225#[serde(rename_all = "snake_case")]
226pub enum GenericArgs {
227    /// `<'a, 32, B: Copy, C = u32>`
228    AngleBracketed {
229        /// The list of each argument on this type.
230        /// ```text
231        /// <'a, 32, B: Copy, C = u32>
232        ///  ^^^^^^
233        /// ```
234        args: Vec<GenericArg>,
235        /// Associated type or constant bindings (e.g. `Item=i32` or `Item: Clone`) for this type.
236        constraints: Vec<AssocItemConstraint>,
237    },
238    /// `Fn(A, B) -> C`
239    Parenthesized {
240        /// The input types, enclosed in parentheses.
241        inputs: Vec<Type>,
242        /// The output type provided after the `->`, if present.
243        output: Option<Type>,
244    },
245    /// `T::method(..)`
246    ReturnTypeNotation,
247}
248
249/// One argument in a list of generic arguments to a path segment.
250///
251/// Part of [`GenericArgs`].
252#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
253#[serde(rename_all = "snake_case")]
254pub enum GenericArg {
255    /// A lifetime argument.
256    /// ```text
257    /// std::borrow::Cow<'static, str>
258    ///                  ^^^^^^^
259    /// ```
260    Lifetime(String),
261    /// A type argument.
262    /// ```text
263    /// std::borrow::Cow<'static, str>
264    ///                           ^^^
265    /// ```
266    Type(Type),
267    /// A constant as a generic argument.
268    /// ```text
269    /// core::array::IntoIter<u32, { 640 * 1024 }>
270    ///                            ^^^^^^^^^^^^^^
271    /// ```
272    Const(Constant),
273    /// A generic argument that's explicitly set to be inferred.
274    /// ```text
275    /// std::vec::Vec::<_>::new()
276    ///                 ^
277    /// ```
278    Infer,
279}
280
281/// A constant.
282#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
283pub struct Constant {
284    /// The stringified expression of this constant. Note that its mapping to the original
285    /// source code is unstable and it's not guaranteed that it'll match the source code.
286    pub expr: String,
287    /// The value of the evaluated expression for this constant, which is only computed for numeric
288    /// types.
289    pub value: Option<String>,
290    /// Whether this constant is a bool, numeric, string, or char literal.
291    pub is_literal: bool,
292}
293
294/// Describes a bound applied to an associated type/constant.
295///
296/// Example:
297/// ```text
298/// IntoIterator<Item = u32, IntoIter: Clone>
299///              ^^^^^^^^^^  ^^^^^^^^^^^^^^^
300/// ```
301#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
302pub struct AssocItemConstraint {
303    /// The name of the associated type/constant.
304    pub name: String,
305    /// Arguments provided to the associated type/constant.
306    pub args: GenericArgs,
307    /// The kind of bound applied to the associated type/constant.
308    pub binding: AssocItemConstraintKind,
309}
310
311/// The way in which an associate type/constant is bound.
312#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
313#[serde(rename_all = "snake_case")]
314pub enum AssocItemConstraintKind {
315    /// The required value/type is specified exactly. e.g.
316    /// ```text
317    /// Iterator<Item = u32, IntoIter: DoubleEndedIterator>
318    ///          ^^^^^^^^^^
319    /// ```
320    Equality(Term),
321    /// The type is required to satisfy a set of bounds.
322    /// ```text
323    /// Iterator<Item = u32, IntoIter: DoubleEndedIterator>
324    ///                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
325    /// ```
326    Constraint(Vec<GenericBound>),
327}
328
329/// An opaque identifier for an item.
330///
331/// It can be used to lookup in [`Crate::index`] or [`Crate::paths`] to resolve it
332/// to an [`Item`].
333///
334/// Id's are only valid within a single JSON blob. They cannot be used to
335/// resolve references between the JSON output's for different crates.
336///
337/// Rustdoc makes no guarantees about the inner value of Id's. Applications
338/// should treat them as opaque keys to lookup items, and avoid attempting
339/// to parse them, or otherwise depend on any implementation details.
340#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
341// FIXME(aDotInTheVoid): Consider making this non-public in rustdoc-types.
342pub struct Id(pub u32);
343
344/// The fundamental kind of an item. Unlike [`ItemEnum`], this does not carry any additional info.
345///
346/// Part of [`ItemSummary`].
347#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
348#[serde(rename_all = "snake_case")]
349pub enum ItemKind {
350    /// A module declaration, e.g. `mod foo;` or `mod foo {}`
351    Module,
352    /// A crate imported via the `extern crate` syntax.
353    ExternCrate,
354    /// An import of 1 or more items into scope, using the `use` keyword.
355    Use,
356    /// A `struct` declaration.
357    Struct,
358    /// A field of a struct.
359    StructField,
360    /// A `union` declaration.
361    Union,
362    /// An `enum` declaration.
363    Enum,
364    /// A variant of a enum.
365    Variant,
366    /// A function declaration, e.g. `fn f() {}`
367    Function,
368    /// A type alias declaration, e.g. `type Pig = std::borrow::Cow<'static, str>;`
369    TypeAlias,
370    /// The declaration of a constant, e.g. `const GREETING: &str = "Hi :3";`
371    Constant,
372    /// A `trait` declaration.
373    Trait,
374    /// A trait alias declaration, e.g. `trait Int = Add + Sub + Mul + Div;`
375    ///
376    /// See [the tracking issue](https://github.com/rust-lang/rust/issues/41517)
377    TraitAlias,
378    /// An `impl` block.
379    Impl,
380    /// A `static` declaration.
381    Static,
382    /// `type`s from an `extern` block.
383    ///
384    /// See [the tracking issue](https://github.com/rust-lang/rust/issues/43467)
385    ExternType,
386    /// A macro declaration.
387    ///
388    /// Corresponds to either `ItemEnum::Macro(_)`
389    /// or `ItemEnum::ProcMacro(ProcMacro { kind: MacroKind::Bang })`
390    Macro,
391    /// A procedural macro attribute.
392    ///
393    /// Corresponds to `ItemEnum::ProcMacro(ProcMacro { kind: MacroKind::Attr })`
394    ProcAttribute,
395    /// A procedural macro usable in the `#[derive()]` attribute.
396    ///
397    /// Corresponds to `ItemEnum::ProcMacro(ProcMacro { kind: MacroKind::Derive })`
398    ProcDerive,
399    /// An associated constant of a trait or a type.
400    AssocConst,
401    /// An associated type of a trait or a type.
402    AssocType,
403    /// A primitive type, e.g. `u32`.
404    ///
405    /// [`Item`]s of this kind only come from the core library.
406    Primitive,
407    /// A keyword declaration.
408    ///
409    /// [`Item`]s of this kind only come from the come library and exist solely
410    /// to carry documentation for the respective keywords.
411    Keyword,
412}
413
414/// Specific fields of an item.
415///
416/// Part of [`Item`].
417#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
418#[serde(rename_all = "snake_case")]
419pub enum ItemEnum {
420    /// A module declaration, e.g. `mod foo;` or `mod foo {}`
421    Module(Module),
422    /// A crate imported via the `extern crate` syntax.
423    ExternCrate {
424        /// The name of the imported crate.
425        name: String,
426        /// If the crate is renamed, this is its name in the crate.
427        rename: Option<String>,
428    },
429    /// An import of 1 or more items into scope, using the `use` keyword.
430    Use(Use),
431
432    /// A `union` declaration.
433    Union(Union),
434    /// A `struct` declaration.
435    Struct(Struct),
436    /// A field of a struct.
437    StructField(Type),
438    /// An `enum` declaration.
439    Enum(Enum),
440    /// A variant of a enum.
441    Variant(Variant),
442
443    /// A function declaration (including methods and other associated functions)
444    Function(Function),
445
446    /// A `trait` declaration.
447    Trait(Trait),
448    /// A trait alias declaration, e.g. `trait Int = Add + Sub + Mul + Div;`
449    ///
450    /// See [the tracking issue](https://github.com/rust-lang/rust/issues/41517)
451    TraitAlias(TraitAlias),
452    /// An `impl` block.
453    Impl(Impl),
454
455    /// A type alias declaration, e.g. `type Pig = std::borrow::Cow<'static, str>;`
456    TypeAlias(TypeAlias),
457    /// The declaration of a constant, e.g. `const GREETING: &str = "Hi :3";`
458    Constant {
459        /// The type of the constant.
460        #[serde(rename = "type")]
461        type_: Type,
462        /// The declared constant itself.
463        #[serde(rename = "const")]
464        const_: Constant,
465    },
466
467    /// A declaration of a `static`.
468    Static(Static),
469
470    /// `type`s from an `extern` block.
471    ///
472    /// See [the tracking issue](https://github.com/rust-lang/rust/issues/43467)
473    ExternType,
474
475    /// A macro_rules! declarative macro. Contains a single string with the source
476    /// representation of the macro with the patterns stripped.
477    Macro(String),
478    /// A procedural macro.
479    ProcMacro(ProcMacro),
480
481    /// A primitive type, e.g. `u32`.
482    ///
483    /// [`Item`]s of this kind only come from the core library.
484    Primitive(Primitive),
485
486    /// An associated constant of a trait or a type.
487    AssocConst {
488        /// The type of the constant.
489        #[serde(rename = "type")]
490        type_: Type,
491        /// Inside a trait declaration, this is the default value for the associated constant,
492        /// if provided.
493        /// Inside an `impl` block, this is the value assigned to the associated constant,
494        /// and will always be present.
495        ///
496        /// The representation is implementation-defined and not guaranteed to be representative of
497        /// either the resulting value or of the source code.
498        ///
499        /// ```rust
500        /// const X: usize = 640 * 1024;
501        /// //               ^^^^^^^^^^
502        /// ```
503        value: Option<String>,
504    },
505    /// An associated type of a trait or a type.
506    AssocType {
507        /// The generic parameters and where clauses on ahis associated type.
508        generics: Generics,
509        /// The bounds for this associated type. e.g.
510        /// ```rust
511        /// trait IntoIterator {
512        ///     type Item;
513        ///     type IntoIter: Iterator<Item = Self::Item>;
514        /// //                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
515        /// }
516        /// ```
517        bounds: Vec<GenericBound>,
518        /// Inside a trait declaration, this is the default for the associated type, if provided.
519        /// Inside an impl block, this is the type assigned to the associated type, and will always
520        /// be present.
521        ///
522        /// ```rust
523        /// type X = usize;
524        /// //       ^^^^^
525        /// ```
526        #[serde(rename = "type")]
527        type_: Option<Type>,
528    },
529}
530
531/// A module declaration, e.g. `mod foo;` or `mod foo {}`.
532#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
533pub struct Module {
534    /// Whether this is the root item of a crate.
535    ///
536    /// This item doesn't correspond to any construction in the source code and is generated by the
537    /// compiler.
538    pub is_crate: bool,
539    /// [`Item`]s declared inside this module.
540    pub items: Vec<Id>,
541    /// If `true`, this module is not part of the public API, but it contains
542    /// items that are re-exported as public API.
543    pub is_stripped: bool,
544}
545
546/// A `union`.
547#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
548pub struct Union {
549    /// The generic parameters and where clauses on this union.
550    pub generics: Generics,
551    /// Whether any fields have been removed from the result, due to being private or hidden.
552    pub has_stripped_fields: bool,
553    /// The list of fields in the union.
554    ///
555    /// All of the corresponding [`Item`]s are of kind [`ItemEnum::StructField`].
556    pub fields: Vec<Id>,
557    /// All impls (both of traits and inherent) for this union.
558    ///
559    /// All of the corresponding [`Item`]s are of kind [`ItemEnum::Impl`].
560    pub impls: Vec<Id>,
561}
562
563/// A `struct`.
564#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
565pub struct Struct {
566    /// The kind of the struct (e.g. unit, tuple-like or struct-like) and the data specific to it,
567    /// i.e. fields.
568    pub kind: StructKind,
569    /// The generic parameters and where clauses on this struct.
570    pub generics: Generics,
571    /// All impls (both of traits and inherent) for this struct.
572    /// All of the corresponding [`Item`]s are of kind [`ItemEnum::Impl`].
573    pub impls: Vec<Id>,
574}
575
576/// The kind of a [`Struct`] and the data specific to it, i.e. fields.
577#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
578#[serde(rename_all = "snake_case")]
579pub enum StructKind {
580    /// A struct with no fields and no parentheses.
581    ///
582    /// ```rust
583    /// pub struct Unit;
584    /// ```
585    Unit,
586    /// A struct with unnamed fields.
587    ///
588    /// All [`Id`]'s will point to [`ItemEnum::StructField`].
589    /// Unlike most of JSON, private and `#[doc(hidden)]` fields will be given as `None`
590    /// instead of being omitted, because order matters.
591    ///
592    /// ```rust
593    /// pub struct TupleStruct(i32);
594    /// pub struct EmptyTupleStruct();
595    /// ```
596    Tuple(Vec<Option<Id>>),
597    /// A struct with named fields.
598    ///
599    /// ```rust
600    /// pub struct PlainStruct { x: i32 }
601    /// pub struct EmptyPlainStruct {}
602    /// ```
603    Plain {
604        /// The list of fields in the struct.
605        ///
606        /// All of the corresponding [`Item`]s are of kind [`ItemEnum::StructField`].
607        fields: Vec<Id>,
608        /// Whether any fields have been removed from the result, due to being private or hidden.
609        has_stripped_fields: bool,
610    },
611}
612
613/// An `enum`.
614#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
615pub struct Enum {
616    /// Information about the type parameters and `where` clauses of the enum.
617    pub generics: Generics,
618    /// Whether any variants have been removed from the result, due to being private or hidden.
619    pub has_stripped_variants: bool,
620    /// The list of variants in the enum.
621    ///
622    /// All of the corresponding [`Item`]s are of kind [`ItemEnum::Variant`]
623    pub variants: Vec<Id>,
624    /// `impl`s for the enum.
625    pub impls: Vec<Id>,
626}
627
628/// A variant of an enum.
629#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
630pub struct Variant {
631    /// Whether the variant is plain, a tuple-like, or struct-like. Contains the fields.
632    pub kind: VariantKind,
633    /// The discriminant, if explicitly specified.
634    pub discriminant: Option<Discriminant>,
635}
636
637/// The kind of an [`Enum`] [`Variant`] and the data specific to it, i.e. fields.
638#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
639#[serde(rename_all = "snake_case")]
640pub enum VariantKind {
641    /// A variant with no parentheses
642    ///
643    /// ```rust
644    /// enum Demo {
645    ///     PlainVariant,
646    ///     PlainWithDiscriminant = 1,
647    /// }
648    /// ```
649    Plain,
650    /// A variant with unnamed fields.
651    ///
652    /// All [`Id`]'s will point to [`ItemEnum::StructField`].
653    /// Unlike most of JSON, `#[doc(hidden)]` fields will be given as `None`
654    /// instead of being omitted, because order matters.
655    ///
656    /// ```rust
657    /// enum Demo {
658    ///     TupleVariant(i32),
659    ///     EmptyTupleVariant(),
660    /// }
661    /// ```
662    Tuple(Vec<Option<Id>>),
663    /// A variant with named fields.
664    ///
665    /// ```rust
666    /// enum Demo {
667    ///     StructVariant { x: i32 },
668    ///     EmptyStructVariant {},
669    /// }
670    /// ```
671    Struct {
672        /// The list of variants in the enum.
673        /// All of the corresponding [`Item`]s are of kind [`ItemEnum::Variant`].
674        fields: Vec<Id>,
675        /// Whether any variants have been removed from the result, due to being private or hidden.
676        has_stripped_fields: bool,
677    },
678}
679
680/// The value that distinguishes a variant in an [`Enum`] from other variants.
681#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
682pub struct Discriminant {
683    /// The expression that produced the discriminant.
684    ///
685    /// Unlike `value`, this preserves the original formatting (eg suffixes,
686    /// hexadecimal, and underscores), making it unsuitable to be machine
687    /// interpreted.
688    ///
689    /// In some cases, when the value is too complex, this may be `"{ _ }"`.
690    /// When this occurs is unstable, and may change without notice.
691    pub expr: String,
692    /// The numerical value of the discriminant. Stored as a string due to
693    /// JSON's poor support for large integers, and the fact that it would need
694    /// to store from [`i128::MIN`] to [`u128::MAX`].
695    pub value: String,
696}
697
698/// A set of fundamental properties of a function.
699#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
700pub struct FunctionHeader {
701    /// Is this function marked as `const`?
702    pub is_const: bool,
703    /// Is this function unsafe?
704    pub is_unsafe: bool,
705    /// Is this function async?
706    pub is_async: bool,
707    /// The ABI used by the function.
708    pub abi: Abi,
709}
710
711/// The ABI (Application Binary Interface) used by a function.
712///
713/// If a variant has an `unwind` field, this means the ABI that it represents can be specified in 2
714/// ways: `extern "_"` and `extern "_-unwind"`, and a value of `true` for that field signifies the
715/// latter variant.
716///
717/// See the [Rustonomicon section](https://doc.rust-lang.org/nightly/nomicon/ffi.html#ffi-and-unwinding)
718/// on unwinding for more info.
719#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
720pub enum Abi {
721    // We only have a concrete listing here for stable ABI's because there are so many
722    // See rustc_ast_passes::feature_gate::PostExpansionVisitor::check_abi for the list
723    /// The default ABI, but that can also be written explicitly with `extern "Rust"`.
724    Rust,
725    /// Can be specified as `extern "C"` or, as a shorthand, just `extern`.
726    C { unwind: bool },
727    /// Can be specified as `extern "cdecl"`.
728    Cdecl { unwind: bool },
729    /// Can be specified as `extern "stdcall"`.
730    Stdcall { unwind: bool },
731    /// Can be specified as `extern "fastcall"`.
732    Fastcall { unwind: bool },
733    /// Can be specified as `extern "aapcs"`.
734    Aapcs { unwind: bool },
735    /// Can be specified as `extern "win64"`.
736    Win64 { unwind: bool },
737    /// Can be specified as `extern "sysv64"`.
738    SysV64 { unwind: bool },
739    /// Can be specified as `extern "system"`.
740    System { unwind: bool },
741    /// Any other ABI, including unstable ones.
742    Other(String),
743}
744
745/// A function declaration (including methods and other associated functions).
746#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
747pub struct Function {
748    /// Information about the function signature, or declaration.
749    pub sig: FunctionSignature,
750    /// Information about the function’s type parameters and `where` clauses.
751    pub generics: Generics,
752    /// Information about core properties of the function, e.g. whether it's `const`, its ABI, etc.
753    pub header: FunctionHeader,
754    /// Whether the function has a body, i.e. an implementation.
755    pub has_body: bool,
756}
757
758/// Generic parameters accepted by an item and `where` clauses imposed on it and the parameters.
759#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
760pub struct Generics {
761    /// A list of generic parameter definitions (e.g. `<T: Clone + Hash, U: Copy>`).
762    pub params: Vec<GenericParamDef>,
763    /// A list of where predicates (e.g. `where T: Iterator, T::Item: Copy`).
764    pub where_predicates: Vec<WherePredicate>,
765}
766
767/// One generic parameter accepted by an item.
768#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
769pub struct GenericParamDef {
770    /// Name of the parameter.
771    /// ```rust
772    /// fn f<'resource, Resource>(x: &'resource Resource) {}
773    /// //    ^^^^^^^^  ^^^^^^^^
774    /// ```
775    pub name: String,
776    /// The kind of the parameter and data specific to a particular parameter kind, e.g. type
777    /// bounds.
778    pub kind: GenericParamDefKind,
779}
780
781/// The kind of a [`GenericParamDef`].
782#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
783#[serde(rename_all = "snake_case")]
784pub enum GenericParamDefKind {
785    /// Denotes a lifetime parameter.
786    Lifetime {
787        /// Lifetimes that this lifetime parameter is required to outlive.
788        ///
789        /// ```rust
790        /// fn f<'a, 'b, 'resource: 'a + 'b>(a: &'a str, b: &'b str, res: &'resource str) {}
791        /// //                      ^^^^^^^
792        /// ```
793        outlives: Vec<String>,
794    },
795
796    /// Denotes a type parameter.
797    Type {
798        /// Bounds applied directly to the type. Note that the bounds from `where` clauses
799        /// that constrain this parameter won't appear here.
800        ///
801        /// ```rust
802        /// fn default2<T: Default>() -> [T; 2] where T: Clone { todo!() }
803        /// //             ^^^^^^^
804        /// ```
805        bounds: Vec<GenericBound>,
806        /// The default type for this parameter, if provided, e.g.
807        ///
808        /// ```rust
809        /// trait PartialEq<Rhs = Self> {}
810        /// //                    ^^^^
811        /// ```
812        default: Option<Type>,
813        /// This is normally `false`, which means that this generic parameter is
814        /// declared in the Rust source text.
815        ///
816        /// If it is `true`, this generic parameter has been introduced by the
817        /// compiler behind the scenes.
818        ///
819        /// # Example
820        ///
821        /// Consider
822        ///
823        /// ```ignore (pseudo-rust)
824        /// pub fn f(_: impl Trait) {}
825        /// ```
826        ///
827        /// The compiler will transform this behind the scenes to
828        ///
829        /// ```ignore (pseudo-rust)
830        /// pub fn f<impl Trait: Trait>(_: impl Trait) {}
831        /// ```
832        ///
833        /// In this example, the generic parameter named `impl Trait` (and which
834        /// is bound by `Trait`) is synthetic, because it was not originally in
835        /// the Rust source text.
836        is_synthetic: bool,
837    },
838
839    /// Denotes a constant parameter.
840    Const {
841        /// The type of the constant as declared.
842        #[serde(rename = "type")]
843        type_: Type,
844        /// The stringified expression for the default value, if provided. It's not guaranteed that
845        /// it'll match the actual source code for the default value.
846        default: Option<String>,
847    },
848}
849
850/// One `where` clause.
851/// ```rust
852/// fn default<T>() -> T where T: Default { T::default() }
853/// //                         ^^^^^^^^^^
854/// ```
855#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
856#[serde(rename_all = "snake_case")]
857pub enum WherePredicate {
858    /// A type is expected to comply with a set of bounds
859    BoundPredicate {
860        /// The type that's being constrained.
861        ///
862        /// ```rust
863        /// fn f<T>(x: T) where for<'a> &'a T: Iterator {}
864        /// //                              ^
865        /// ```
866        #[serde(rename = "type")]
867        type_: Type,
868        /// The set of bounds that constrain the type.
869        ///
870        /// ```rust
871        /// fn f<T>(x: T) where for<'a> &'a T: Iterator {}
872        /// //                                 ^^^^^^^^
873        /// ```
874        bounds: Vec<GenericBound>,
875        /// Used for Higher-Rank Trait Bounds (HRTBs)
876        /// ```rust
877        /// fn f<T>(x: T) where for<'a> &'a T: Iterator {}
878        /// //                  ^^^^^^^
879        /// ```
880        generic_params: Vec<GenericParamDef>,
881    },
882
883    /// A lifetime is expected to outlive other lifetimes.
884    LifetimePredicate {
885        /// The name of the lifetime.
886        lifetime: String,
887        /// The lifetimes that must be encompassed by the lifetime.
888        outlives: Vec<String>,
889    },
890
891    /// A type must exactly equal another type.
892    EqPredicate {
893        /// The left side of the equation.
894        lhs: Type,
895        /// The right side of the equation.
896        rhs: Term,
897    },
898}
899
900/// Either a trait bound or a lifetime bound.
901#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
902#[serde(rename_all = "snake_case")]
903pub enum GenericBound {
904    /// A trait bound.
905    TraitBound {
906        /// The full path to the trait.
907        #[serde(rename = "trait")]
908        trait_: Path,
909        /// Used for Higher-Rank Trait Bounds (HRTBs)
910        /// ```text
911        /// where F: for<'a, 'b> Fn(&'a u8, &'b u8)
912        ///          ^^^^^^^^^^^
913        ///          |
914        ///          this part
915        /// ```
916        generic_params: Vec<GenericParamDef>,
917        /// The context for which a trait is supposed to be used, e.g. `const
918        modifier: TraitBoundModifier,
919    },
920    /// A lifetime bound, e.g.
921    /// ```rust
922    /// fn f<'a, T>(x: &'a str, y: &T) where T: 'a {}
923    /// //                                     ^^^
924    /// ```
925    Outlives(String),
926    /// `use<'a, T>` precise-capturing bound syntax
927    Use(Vec<PreciseCapturingArg>),
928}
929
930/// A set of modifiers applied to a trait.
931#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
932#[serde(rename_all = "snake_case")]
933pub enum TraitBoundModifier {
934    /// Marks the absence of a modifier.
935    None,
936    /// Indicates that the trait bound relaxes a trait bound applied to a parameter by default,
937    /// e.g. `T: Sized?`, the `Sized` trait is required for all generic type parameters by default
938    /// unless specified otherwise with this modifier.
939    Maybe,
940    /// Indicates that the trait bound must be applicable in both a run-time and a compile-time
941    /// context.
942    MaybeConst,
943}
944
945/// One precise capturing argument. See [the rust reference](https://doc.rust-lang.org/reference/types/impl-trait.html#precise-capturing).
946#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
947#[serde(rename_all = "snake_case")]
948pub enum PreciseCapturingArg {
949    /// A lifetime.
950    /// ```rust
951    /// pub fn hello<'a, T, const N: usize>() -> impl Sized + use<'a, T, N> {}
952    /// //                                                        ^^
953    Lifetime(String),
954    /// A type or constant parameter.
955    /// ```rust
956    /// pub fn hello<'a, T, const N: usize>() -> impl Sized + use<'a, T, N> {}
957    /// //                                                            ^  ^
958    Param(String),
959}
960
961/// Either a type or a constant, usually stored as the right-hand side of an equation in places like
962/// [`AssocItemConstraint`]
963#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
964#[serde(rename_all = "snake_case")]
965pub enum Term {
966    /// A type.
967    ///
968    /// ```rust
969    /// fn f(x: impl IntoIterator<Item = u32>) {}
970    /// //                               ^^^
971    /// ```
972    Type(Type),
973    /// A constant.
974    ///
975    /// ```ignore (incomplete feature in the snippet)
976    /// trait Foo {
977    ///     const BAR: usize;
978    /// }
979    ///
980    /// fn f(x: impl Foo<BAR = 42>) {}
981    /// //                     ^^
982    /// ```
983    Constant(Constant),
984}
985
986/// A type.
987#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
988#[serde(rename_all = "snake_case")]
989pub enum Type {
990    /// Structs, enums, unions and type aliases, e.g. `std::option::Option<u32>`
991    ResolvedPath(Path),
992    /// Dynamic trait object type (`dyn Trait`).
993    DynTrait(DynTrait),
994    /// Parameterized types. The contained string is the name of the parameter.
995    Generic(String),
996    /// Built-in numeric types (e.g. `u32`, `f32`), `bool`, `char`.
997    Primitive(String),
998    /// A function pointer type, e.g. `fn(u32) -> u32`, `extern "C" fn() -> *const u8`
999    FunctionPointer(Box<FunctionPointer>),
1000    /// A tuple type, e.g. `(String, u32, Box<usize>)`
1001    Tuple(Vec<Type>),
1002    /// An unsized slice type, e.g. `[u32]`.
1003    Slice(Box<Type>),
1004    /// An array type, e.g. `[u32; 15]`
1005    Array {
1006        /// The type of the contained element.
1007        #[serde(rename = "type")]
1008        type_: Box<Type>,
1009        /// The stringified expression that is the length of the array.
1010        ///
1011        /// Keep in mind that it's not guaranteed to match the actual source code of the expression.
1012        len: String,
1013    },
1014    /// A pattern type, e.g. `u32 is 1..`
1015    ///
1016    /// See [the tracking issue](https://github.com/rust-lang/rust/issues/123646)
1017    Pat {
1018        /// The base type, e.g. the `u32` in `u32 is 1..`
1019        #[serde(rename = "type")]
1020        type_: Box<Type>,
1021        #[doc(hidden)]
1022        __pat_unstable_do_not_use: String,
1023    },
1024    /// An opaque type that satisfies a set of bounds, `impl TraitA + TraitB + ...`
1025    ImplTrait(Vec<GenericBound>),
1026    /// A type that's left to be inferred, `_`
1027    Infer,
1028    /// A raw pointer type, e.g. `*mut u32`, `*const u8`, etc.
1029    RawPointer {
1030        /// This is `true` for `*mut _` and `false` for `*const _`.
1031        is_mutable: bool,
1032        /// The type of the pointee.
1033        #[serde(rename = "type")]
1034        type_: Box<Type>,
1035    },
1036    /// `&'a mut String`, `&str`, etc.
1037    BorrowedRef {
1038        /// The name of the lifetime of the reference, if provided.
1039        lifetime: Option<String>,
1040        /// This is `true` for `&mut i32` and `false` for `&i32`
1041        is_mutable: bool,
1042        /// The type of the pointee, e.g. the `i32` in `&'a mut i32`
1043        #[serde(rename = "type")]
1044        type_: Box<Type>,
1045    },
1046    /// Associated types like `<Type as Trait>::Name` and `T::Item` where
1047    /// `T: Iterator` or inherent associated types like `Struct::Name`.
1048    QualifiedPath {
1049        /// The name of the associated type in the parent type.
1050        ///
1051        /// ```ignore (incomplete expression)
1052        /// <core::array::IntoIter<u32, 42> as Iterator>::Item
1053        /// //                                            ^^^^
1054        /// ```
1055        name: String,
1056        /// The generic arguments provided to the associated type.
1057        ///
1058        /// ```ignore (incomplete expression)
1059        /// <core::slice::IterMut<'static, u32> as BetterIterator>::Item<'static>
1060        /// //                                                          ^^^^^^^^^
1061        /// ```
1062        args: Box<GenericArgs>,
1063        /// The type with which this type is associated.
1064        ///
1065        /// ```ignore (incomplete expression)
1066        /// <core::array::IntoIter<u32, 42> as Iterator>::Item
1067        /// // ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1068        /// ```
1069        self_type: Box<Type>,
1070        /// `None` iff this is an *inherent* associated type.
1071        #[serde(rename = "trait")]
1072        trait_: Option<Path>,
1073    },
1074}
1075
1076/// A type that has a simple path to it. This is the kind of type of structs, unions, enums, etc.
1077#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
1078pub struct Path {
1079    /// The path of the type.
1080    ///
1081    /// This will be the path that is *used* (not where it is defined), so
1082    /// multiple `Path`s may have different values for this field even if
1083    /// they all refer to the same item. e.g.
1084    ///
1085    /// ```rust
1086    /// pub type Vec1 = std::vec::Vec<i32>; // path: "std::vec::Vec"
1087    /// pub type Vec2 = Vec<i32>; // path: "Vec"
1088    /// pub type Vec3 = std::prelude::v1::Vec<i32>; // path: "std::prelude::v1::Vec"
1089    /// ```
1090    //
1091    // Example tested in ./tests/rustdoc-json/path_name.rs
1092    pub path: String,
1093    /// The ID of the type.
1094    pub id: Id,
1095    /// Generic arguments to the type.
1096    ///
1097    /// ```ignore (incomplete expression)
1098    /// std::borrow::Cow<'static, str>
1099    /// //              ^^^^^^^^^^^^^^
1100    /// ```
1101    pub args: Option<Box<GenericArgs>>,
1102}
1103
1104/// A type that is a function pointer.
1105#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
1106pub struct FunctionPointer {
1107    /// The signature of the function.
1108    pub sig: FunctionSignature,
1109    /// Used for Higher-Rank Trait Bounds (HRTBs)
1110    ///
1111    /// ```ignore (incomplete expression)
1112    ///    for<'c> fn(val: &'c i32) -> i32
1113    /// // ^^^^^^^
1114    /// ```
1115    pub generic_params: Vec<GenericParamDef>,
1116    /// The core properties of the function, such as the ABI it conforms to, whether it's unsafe, etc.
1117    pub header: FunctionHeader,
1118}
1119
1120/// The signature of a function.
1121#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
1122pub struct FunctionSignature {
1123    /// List of argument names and their type.
1124    ///
1125    /// Note that not all names will be valid identifiers, as some of
1126    /// them may be patterns.
1127    pub inputs: Vec<(String, Type)>,
1128    /// The output type, if specified.
1129    pub output: Option<Type>,
1130    /// Whether the function accepts an arbitrary amount of trailing arguments the C way.
1131    ///
1132    /// ```ignore (incomplete code)
1133    /// fn printf(fmt: &str, ...);
1134    /// ```
1135    pub is_c_variadic: bool,
1136}
1137
1138/// A `trait` declaration.
1139#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
1140pub struct Trait {
1141    /// Whether the trait is marked `auto` and is thus implemented automatically
1142    /// for all applicable types.
1143    pub is_auto: bool,
1144    /// Whether the trait is marked as `unsafe`.
1145    pub is_unsafe: bool,
1146    /// Whether the trait is [dyn compatible](https://doc.rust-lang.org/reference/items/traits.html#dyn-compatibility)[^1].
1147    ///
1148    /// [^1]: Formerly known as "object safe".
1149    pub is_dyn_compatible: bool,
1150    /// Associated [`Item`]s that can/must be implemented by the `impl` blocks.
1151    pub items: Vec<Id>,
1152    /// Information about the type parameters and `where` clauses of the trait.
1153    pub generics: Generics,
1154    /// Constraints that must be met by the implementor of the trait.
1155    pub bounds: Vec<GenericBound>,
1156    /// The implementations of the trait.
1157    pub implementations: Vec<Id>,
1158}
1159
1160/// A trait alias declaration, e.g. `trait Int = Add + Sub + Mul + Div;`
1161///
1162/// See [the tracking issue](https://github.com/rust-lang/rust/issues/41517)
1163#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
1164pub struct TraitAlias {
1165    /// Information about the type parameters and `where` clauses of the alias.
1166    pub generics: Generics,
1167    /// The bounds that are associated with the alias.
1168    pub params: Vec<GenericBound>,
1169}
1170
1171/// An `impl` block.
1172#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
1173pub struct Impl {
1174    /// Whether this impl is for an unsafe trait.
1175    pub is_unsafe: bool,
1176    /// Information about the impl’s type parameters and `where` clauses.
1177    pub generics: Generics,
1178    /// The list of the names of all the trait methods that weren't mentioned in this impl but
1179    /// were provided by the trait itself.
1180    ///
1181    /// For example, for this impl of the [`PartialEq`] trait:
1182    /// ```rust
1183    /// struct Foo;
1184    ///
1185    /// impl PartialEq for Foo {
1186    ///     fn eq(&self, other: &Self) -> bool { todo!() }
1187    /// }
1188    /// ```
1189    /// This field will be `["ne"]`, as it has a default implementation defined for it.
1190    pub provided_trait_methods: Vec<String>,
1191    /// The trait being implemented or `None` if the impl is inherent, which means
1192    /// `impl Struct {}` as opposed to `impl Trait for Struct {}`.
1193    #[serde(rename = "trait")]
1194    pub trait_: Option<Path>,
1195    /// The type that the impl block is for.
1196    #[serde(rename = "for")]
1197    pub for_: Type,
1198    /// The list of associated items contained in this impl block.
1199    pub items: Vec<Id>,
1200    /// Whether this is a negative impl (e.g. `!Sized` or `!Send`).
1201    pub is_negative: bool,
1202    /// Whether this is an impl that’s implied by the compiler
1203    /// (for autotraits, e.g. `Send` or `Sync`).
1204    pub is_synthetic: bool,
1205    // FIXME: document this
1206    pub blanket_impl: Option<Type>,
1207}
1208
1209/// A `use` statement.
1210#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
1211#[serde(rename_all = "snake_case")]
1212pub struct Use {
1213    /// The full path being imported.
1214    pub source: String,
1215    /// May be different from the last segment of `source` when renaming imports:
1216    /// `use source as name;`
1217    pub name: String,
1218    /// The ID of the item being imported. Will be `None` in case of re-exports of primitives:
1219    /// ```rust
1220    /// pub use i32 as my_i32;
1221    /// ```
1222    pub id: Option<Id>,
1223    /// Whether this statement is a wildcard `use`, e.g. `use source::*;`
1224    pub is_glob: bool,
1225}
1226
1227/// A procedural macro.
1228#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
1229pub struct ProcMacro {
1230    /// How this macro is supposed to be called: `foo!()`, `#[foo]` or `#[derive(foo)]`
1231    pub kind: MacroKind,
1232    /// Helper attributes defined by a macro to be used inside it.
1233    ///
1234    /// Defined only for derive macros.
1235    ///
1236    /// E.g. the [`Default`] derive macro defines a `#[default]` helper attribute so that one can
1237    /// do:
1238    ///
1239    /// ```rust
1240    /// #[derive(Default)]
1241    /// enum Option<T> {
1242    ///     #[default]
1243    ///     None,
1244    ///     Some(T),
1245    /// }
1246    /// ```
1247    pub helpers: Vec<String>,
1248}
1249
1250/// The way a [`ProcMacro`] is declared to be used.
1251#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
1252#[serde(rename_all = "snake_case")]
1253pub enum MacroKind {
1254    /// A bang macro `foo!()`.
1255    Bang,
1256    /// An attribute macro `#[foo]`.
1257    Attr,
1258    /// A derive macro `#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]`
1259    Derive,
1260}
1261
1262/// A type alias declaration, e.g. `type Pig = std::borrow::Cow<'static, str>;`
1263#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
1264pub struct TypeAlias {
1265    /// The type referred to by this alias.
1266    #[serde(rename = "type")]
1267    pub type_: Type,
1268    /// Information about the type parameters and `where` clauses of the alias.
1269    pub generics: Generics,
1270}
1271
1272/// A `static` declaration.
1273#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
1274pub struct Static {
1275    /// The type of the static.
1276    #[serde(rename = "type")]
1277    pub type_: Type,
1278    /// This is `true` for mutable statics, declared as `static mut X: T = f();`
1279    pub is_mutable: bool,
1280    /// The stringified expression for the initial value.
1281    ///
1282    /// It's not guaranteed that it'll match the actual source code for the initial value.
1283    pub expr: String,
1284
1285    /// Is the static `unsafe`?
1286    ///
1287    /// This is only true if it's in an `extern` block, and not explicity marked
1288    /// as `safe`.
1289    ///
1290    /// ```rust
1291    /// unsafe extern {
1292    ///     static A: i32;      // unsafe
1293    ///     safe static B: i32; // safe
1294    /// }
1295    ///
1296    /// static C: i32 = 0;     // safe
1297    /// static mut D: i32 = 0; // safe
1298    /// ```
1299    pub is_unsafe: bool,
1300}
1301
1302/// A primitive type declaration. Declarations of this kind can only come from the core library.
1303#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
1304pub struct Primitive {
1305    /// The name of the type.
1306    pub name: String,
1307    /// The implementations, inherent and of traits, on the primitive type.
1308    pub impls: Vec<Id>,
1309}
1310
1311#[cfg(test)]
1312mod tests;