Enum AttributeKind

pub enum AttributeKind {
    AllowConstFnUnstable(ThinVec<Symbol>),
    AllowInternalUnstable(ThinVec<(Symbol, Span)>),
    BodyStability {
        stability: DefaultBodyStability,
        span: Span,
    },
    Confusables {
        symbols: ThinVec<Symbol>,
        first_span: Span,
    },
    ConstStability {
        stability: PartialConstStability,
        span: Span,
    },
    ConstStabilityIndirect,
    Deprecation {
        deprecation: Deprecation,
        span: Span,
    },
    Diagnostic(DiagnosticAttribute),
    DocComment {
        style: AttrStyle,
        kind: CommentKind,
        span: Span,
        comment: Symbol,
    },
    MacroTransparency(Transparency),
    Repr(ThinVec<(ReprAttr, Span)>),
    RustcMacroEdition2021,
    Stability {
        stability: Stability,
        span: Span,
    },
}

Represent parsed, built in, inert attributes.

That means attributes that are not actually ever expanded. For more information on this, see the module docs on the rustc_attr_parsing crate. They’re instead used as markers, to guide the compilation process in various way in most every stage of the compiler. These are kept around after the AST, into the HIR and further on.

The word “parsed” could be a little misleading here, because the parser already parses attributes early on. However, the result, an ast::Attribute is only parsed at a high level, still containing a token stream in many cases. That is because the structure of the contents varies from attribute to attribute. With a parsed attribute I mean that each attribute is processed individually into a final structure, which on-site (the place where the attribute is useful for, think the the place where must_use is checked) little to no extra parsing or validating needs to happen.

For more docs, look in rustc_attr_parsing.

Variants

AllowConstFnUnstable(ThinVec<Symbol>)

AllowInternalUnstable(ThinVec<(Symbol, Span)>)

BodyStability

Fields

stability: DefaultBodyStability

span: Span

Span of the #[rustc_default_body_unstable(...)] attribute

Confusables

Fields

symbols: ThinVec<Symbol>

first_span: Span

ConstStability

Fields

stability: PartialConstStability

span: Span

Span of the #[rustc_const_stable(...)] or #[rustc_const_unstable(...)] attribute

ConstStabilityIndirect

Deprecation

Fields

deprecation: Deprecation

span: Span

Diagnostic(DiagnosticAttribute)

DocComment

Fields

style: AttrStyle

kind: CommentKind

span: Span

comment: Symbol

MacroTransparency(Transparency)

Repr(ThinVec<(ReprAttr, Span)>)

RustcMacroEdition2021

Stability

Fields

stability: Stability

span: Span

Span of the #[stable(...)] or #[unstable(...)] attribute

Trait Implementations

impl Clone for AttributeKind

fn clone(&self) -> AttributeKind

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for AttributeKind

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl<__D> Decodable<__D> for AttributeKind

where __D: SpanDecoder,

fn decode(__decoder: &mut __D) -> AttributeKind

impl<__E> Encodable<__E> for AttributeKind

where __E: SpanEncoder,

fn encode(&self, __encoder: &mut __E)

impl<__CTX> HashStable<__CTX> for AttributeKind

where __CTX: HashStableContext,

fn hash_stable( &self, __hcx: &mut __CTX, __hasher: &mut StableHasher<SipHasher128>, )

impl PrintAttribute for AttributeKind

fn should_render(&self) -> bool

Whether or not this will render as something meaningful, or if it’s skipped (which will force the containing struct to also skip printing a comma and the field name).

fn print_attribute(&self, __p: &mut Printer)

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 32 bytes

Size for each variant:

• AllowConstFnUnstable: 16 bytes
• AllowInternalUnstable: 16 bytes
• BodyStability: 32 bytes
• Confusables: 24 bytes
• ConstStability: 32 bytes
• ConstStabilityIndirect: 0 bytes
• Deprecation: 28 bytes
• Diagnostic: 5 bytes
• DocComment: 20 bytes
• MacroTransparency: 5 bytes
• Repr: 16 bytes
• RustcMacroEdition2021: 0 bytes
• Stability: 32 bytes