rust/zerocopy-derive/repr.rs

Source file repositories/reference/linux-study-clean/rust/zerocopy-derive/repr.rs

File Facts

System
Linux kernel
Corpus path
rust/zerocopy-derive/repr.rs
Extension
.rs
Size
33073 bytes
Lines
852
Domain
Rust Kernel Layer
Bucket
Rust API Membrane
Inferred role
Rust Kernel Layer: implementation source
Status
source implementation candidate

Why This File Exists

Rust-side wrappers and abstractions around kernel C APIs, ownership contracts, allocation, synchronization, and module integration.

Dependency Surface

Detected Declarations

Annotated Snippet

if let Some(n) = self.get_align().filter(|n| n.t.get() > 1) {
            Err(Error::new(
                n.span,
                "cannot derive `Unaligned` on type with alignment greater than 1",
            ))
        } else {
            Ok(())
        }
    }
}

impl<Prim> Repr<Prim, NonZeroU32> {
    /// Does `self` describe a `#[repr(packed)]` or `#[repr(packed(1))]` type?
    pub(crate) fn is_packed_1(&self) -> bool {
        self.get_packed().map(|n| n.get() == 1).unwrap_or(false)
    }
}

impl<Packed> Repr<PrimitiveRepr, Packed> {
    fn get_primitive(&self) -> Option<&PrimitiveRepr> {
        use CompoundRepr::*;
        use Repr::*;
        if let Compound(Spanned { t: Primitive(p), span: _ }, _align) = self {
            Some(p)
        } else {
            None
        }
    }

    /// Does `self` describe a `#[repr(u8)]` type?
    pub(crate) fn is_u8(&self) -> bool {
        matches!(self.get_primitive(), Some(PrimitiveRepr::U8))
    }

    /// Does `self` describe a `#[repr(i8)]` type?
    pub(crate) fn is_i8(&self) -> bool {
        matches!(self.get_primitive(), Some(PrimitiveRepr::I8))
    }
}

impl<Prim, Packed> ToTokens for Repr<Prim, Packed>
where
    Prim: With<PrimitiveRepr> + Copy,
    Packed: With<NonZeroU32> + Copy,
{
    fn to_tokens(&self, ts: &mut TokenStream) {
        use Repr::*;
        match self {
            Transparent(span) => ts.append_all(quote_spanned! { *span=> #[repr(transparent)] }),
            Compound(repr, align) => {
                repr.to_tokens(ts);
                if let Some(align) = align {
                    align.to_tokens(ts);
                }
            }
        }
    }
}

impl<Prim: With<PrimitiveRepr> + Copy> ToTokens for Spanned<CompoundRepr<Prim>> {
    fn to_tokens(&self, ts: &mut TokenStream) {
        use CompoundRepr::*;
        match &self.t {
            C => ts.append_all(quote_spanned! { self.span=> #[repr(C)] }),
            Rust => ts.append_all(quote_spanned! { self.span=> #[repr(Rust)] }),
            Primitive(prim) => prim.with(|prim| Spanned::new(prim, self.span).to_tokens(ts)),
        }
    }
}

impl ToTokens for Spanned<PrimitiveRepr> {
    fn to_tokens(&self, ts: &mut TokenStream) {
        use PrimitiveRepr::*;
        match self.t {
            U8 => ts.append_all(quote_spanned! { self.span => #[repr(u8)] }),
            U16 => ts.append_all(quote_spanned! { self.span => #[repr(u16)] }),
            U32 => ts.append_all(quote_spanned! { self.span => #[repr(u32)] }),
            U64 => ts.append_all(quote_spanned! { self.span => #[repr(u64)] }),
            U128 => ts.append_all(quote_spanned! { self.span => #[repr(u128)] }),
            Usize => ts.append_all(quote_spanned! { self.span => #[repr(usize)] }),
            I8 => ts.append_all(quote_spanned! { self.span => #[repr(i8)] }),
            I16 => ts.append_all(quote_spanned! { self.span => #[repr(i16)] }),
            I32 => ts.append_all(quote_spanned! { self.span => #[repr(i32)] }),
            I64 => ts.append_all(quote_spanned! { self.span => #[repr(i64)] }),
            I128 => ts.append_all(quote_spanned! { self.span => #[repr(i128)] }),
            Isize => ts.append_all(quote_spanned! { self.span => #[repr(isize)] }),
        }
    }
}

Annotation

Implementation Notes