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