diff --git a/derive/src/lib.rs b/derive/src/lib.rs index 20f4b0f..ee8f235 100644 --- a/derive/src/lib.rs +++ b/derive/src/lib.rs @@ -9,8 +9,8 @@ use quote::quote; use syn::{parse_macro_input, DeriveInput, Result}; use crate::traits::{ - AnyBitPattern, CheckedBitPattern, Contiguous, Derivable, NoUninit, Pod, - TransparentWrapper, Zeroable, + bytemuck_crate_name, AnyBitPattern, CheckedBitPattern, Contiguous, Derivable, + NoUninit, Pod, TransparentWrapper, Zeroable, }; /// Derive the `Pod` trait for a struct @@ -87,7 +87,7 @@ use crate::traits::{ /// /// let _: u32 = bytemuck::cast(Generic { a: 4u32, b: PhantomData:: }); /// ``` -#[proc_macro_derive(Pod)] +#[proc_macro_derive(Pod, attributes(bytemuck))] pub fn derive_pod(input: proc_macro::TokenStream) -> proc_macro::TokenStream { let expanded = derive_marker_trait::(parse_macro_input!(input as DeriveInput)); @@ -103,7 +103,7 @@ pub fn derive_pod(input: proc_macro::TokenStream) -> proc_macro::TokenStream { /// The following constraints need to be satisfied for the macro to succeed /// /// - All fields in the struct must to implement `AnyBitPattern` -#[proc_macro_derive(AnyBitPattern)] +#[proc_macro_derive(AnyBitPattern, attributes(bytemuck))] pub fn derive_anybitpattern( input: proc_macro::TokenStream, ) -> proc_macro::TokenStream { @@ -192,7 +192,7 @@ pub fn derive_anybitpattern( /// # } /// ZeroableWhenTIsZeroable::::zeroed(); /// ``` -#[proc_macro_derive(Zeroable, attributes(zeroable))] +#[proc_macro_derive(Zeroable, attributes(bytemuck, zeroable))] pub fn derive_zeroable( input: proc_macro::TokenStream, ) -> proc_macro::TokenStream { @@ -319,7 +319,7 @@ pub fn derive_maybe_pod( /// another_extra: NonTransparentSafeZST, // not `Zeroable` /// } /// ``` -#[proc_macro_derive(TransparentWrapper, attributes(transparent))] +#[proc_macro_derive(TransparentWrapper, attributes(bytemuck, transparent))] pub fn derive_transparent( input: proc_macro::TokenStream, ) -> proc_macro::TokenStream { @@ -394,6 +394,7 @@ pub fn derive_byte_eq( input: proc_macro::TokenStream, ) -> proc_macro::TokenStream { let input = parse_macro_input!(input as DeriveInput); + let crate_name = bytemuck_crate_name(&input); let ident = input.ident; proc_macro::TokenStream::from(quote! { @@ -401,7 +402,7 @@ pub fn derive_byte_eq( #[inline] #[must_use] fn eq(&self, other: &Self) -> bool { - ::bytemuck::bytes_of(self) == ::bytemuck::bytes_of(other) + #crate_name::bytes_of(self) == #crate_name::bytes_of(other) } } impl ::core::cmp::Eq for #ident { } @@ -434,18 +435,19 @@ pub fn derive_byte_hash( input: proc_macro::TokenStream, ) -> proc_macro::TokenStream { let input = parse_macro_input!(input as DeriveInput); + let crate_name = bytemuck_crate_name(&input); let ident = input.ident; proc_macro::TokenStream::from(quote! { impl ::core::hash::Hash for #ident { #[inline] fn hash(&self, state: &mut H) { - ::core::hash::Hash::hash_slice(::bytemuck::bytes_of(self), state) + ::core::hash::Hash::hash_slice(#crate_name::bytes_of(self), state) } #[inline] fn hash_slice(data: &[Self], state: &mut H) { - ::core::hash::Hash::hash_slice(::bytemuck::cast_slice::<_, u8>(data), state) + ::core::hash::Hash::hash_slice(#crate_name::cast_slice::<_, u8>(data), state) } } }) @@ -518,7 +520,8 @@ fn find_and_parse_helper_attributes( fn derive_marker_trait_inner( mut input: DeriveInput, ) -> Result { - let trait_ = Trait::ident(&input)?; + let crate_name = bytemuck_crate_name(&input); + let trait_ = Trait::ident(&input, &crate_name)?; // If this trait allows explicit bounds, and any explicit bounds were given, // then use those explicit bounds. Else, apply the default bounds (bound // each generic type on this trait). @@ -585,10 +588,12 @@ fn derive_marker_trait_inner( input.generics.split_for_impl(); Trait::check_attributes(&input.data, &input.attrs)?; - let asserts = Trait::asserts(&input)?; - let (trait_impl_extras, trait_impl) = Trait::trait_impl(&input)?; + let asserts = Trait::asserts(&input, &crate_name)?; + let (trait_impl_extras, trait_impl) = Trait::trait_impl(&input, &crate_name)?; - let implies_trait = if let Some(implies_trait) = Trait::implies_trait() { + let implies_trait = if let Some(implies_trait) = + Trait::implies_trait(&crate_name) + { quote!(unsafe impl #impl_generics #implies_trait for #name #ty_generics #where_clause {}) } else { quote!() diff --git a/derive/src/traits.rs b/derive/src/traits.rs index c0ddf61..f99d722 100644 --- a/derive/src/traits.rs +++ b/derive/src/traits.rs @@ -21,17 +21,17 @@ macro_rules! bail { } pub trait Derivable { - fn ident(input: &DeriveInput) -> Result; - fn implies_trait() -> Option { + fn ident(input: &DeriveInput, crate_name: &TokenStream) -> Result; + fn implies_trait(_crate_name: &TokenStream) -> Option { None } - fn asserts(_input: &DeriveInput) -> Result { + fn asserts(_input: &DeriveInput, _crate_name: &TokenStream) -> Result { Ok(quote!()) } fn check_attributes(_ty: &Data, _attributes: &[Attribute]) -> Result<()> { Ok(()) } - fn trait_impl(_input: &DeriveInput) -> Result<(TokenStream, TokenStream)> { + fn trait_impl(_input: &DeriveInput, _crate_name: &TokenStream) -> Result<(TokenStream, TokenStream)> { Ok((quote!(), quote!())) } fn requires_where_clause() -> bool { @@ -45,11 +45,11 @@ pub trait Derivable { pub struct Pod; impl Derivable for Pod { - fn ident(_: &DeriveInput) -> Result { - Ok(syn::parse_quote!(::bytemuck::Pod)) + fn ident(_: &DeriveInput, crate_name: &TokenStream) -> Result { + Ok(syn::parse_quote!(#crate_name::Pod)) } - fn asserts(input: &DeriveInput) -> Result { + fn asserts(input: &DeriveInput, crate_name: &TokenStream) -> Result { let repr = get_repr(&input.attrs)?; let completly_packed = @@ -71,7 +71,7 @@ impl Derivable for Pod { None }; let assert_fields_are_pod = - generate_fields_are_trait(input, Self::ident(input)?)?; + generate_fields_are_trait(input, Self::ident(input, crate_name)?)?; Ok(quote!( #assert_no_padding @@ -98,18 +98,18 @@ impl Derivable for Pod { pub struct AnyBitPattern; impl Derivable for AnyBitPattern { - fn ident(_: &DeriveInput) -> Result { - Ok(syn::parse_quote!(::bytemuck::AnyBitPattern)) + fn ident(_: &DeriveInput, crate_name: &TokenStream) -> Result { + Ok(syn::parse_quote!(#crate_name::AnyBitPattern)) } - fn implies_trait() -> Option { - Some(quote!(::bytemuck::Zeroable)) + fn implies_trait(crate_name: &TokenStream) -> Option { + Some(quote!(#crate_name::Zeroable)) } - fn asserts(input: &DeriveInput) -> Result { + fn asserts(input: &DeriveInput, crate_name: &TokenStream) -> Result { match &input.data { Data::Union(_) => Ok(quote!()), // unions are always `AnyBitPattern` - Data::Struct(_) => generate_fields_are_trait(input, Self::ident(input)?), + Data::Struct(_) => generate_fields_are_trait(input, Self::ident(input, crate_name)?), Data::Enum(_) => { bail!("Deriving AnyBitPattern is not supported for enums") } @@ -120,14 +120,14 @@ impl Derivable for AnyBitPattern { pub struct Zeroable; impl Derivable for Zeroable { - fn ident(_: &DeriveInput) -> Result { - Ok(syn::parse_quote!(::bytemuck::Zeroable)) + fn ident(_: &DeriveInput, crate_name: &TokenStream) -> Result { + Ok(syn::parse_quote!(#crate_name::Zeroable)) } - fn asserts(input: &DeriveInput) -> Result { + fn asserts(input: &DeriveInput, crate_name: &TokenStream) -> Result { match &input.data { Data::Union(_) => Ok(quote!()), // unions are always `Zeroable` - Data::Struct(_) => generate_fields_are_trait(input, Self::ident(input)?), + Data::Struct(_) => generate_fields_are_trait(input, Self::ident(input, crate_name)?), Data::Enum(_) => bail!("Deriving Zeroable is not supported for enums"), } } @@ -140,8 +140,8 @@ impl Derivable for Zeroable { pub struct NoUninit; impl Derivable for NoUninit { - fn ident(_: &DeriveInput) -> Result { - Ok(syn::parse_quote!(::bytemuck::NoUninit)) + fn ident(_: &DeriveInput, crate_name: &TokenStream) -> Result { + Ok(syn::parse_quote!(#crate_name::NoUninit)) } fn check_attributes(ty: &Data, attributes: &[Attribute]) -> Result<()> { @@ -160,7 +160,7 @@ impl Derivable for NoUninit { } } - fn asserts(input: &DeriveInput) -> Result { + fn asserts(input: &DeriveInput, crate_name: &TokenStream) -> Result { if !input.generics.params.is_empty() { bail!("NoUninit cannot be derived for structs containing generic parameters because the padding requirements can't be verified for generic structs"); } @@ -169,7 +169,7 @@ impl Derivable for NoUninit { Data::Struct(DataStruct { .. }) => { let assert_no_padding = generate_assert_no_padding(&input)?; let assert_fields_are_no_padding = - generate_fields_are_trait(&input, Self::ident(input)?)?; + generate_fields_are_trait(&input, Self::ident(input, crate_name)?)?; Ok(quote!( #assert_no_padding @@ -187,7 +187,7 @@ impl Derivable for NoUninit { } } - fn trait_impl(_input: &DeriveInput) -> Result<(TokenStream, TokenStream)> { + fn trait_impl(_input: &DeriveInput, _crate_name: &TokenStream) -> Result<(TokenStream, TokenStream)> { Ok((quote!(), quote!())) } } @@ -195,8 +195,8 @@ impl Derivable for NoUninit { pub struct CheckedBitPattern; impl Derivable for CheckedBitPattern { - fn ident(_: &DeriveInput) -> Result { - Ok(syn::parse_quote!(::bytemuck::CheckedBitPattern)) + fn ident(_: &DeriveInput, crate_name: &TokenStream) -> Result { + Ok(syn::parse_quote!(#crate_name::CheckedBitPattern)) } fn check_attributes(ty: &Data, attributes: &[Attribute]) -> Result<()> { @@ -223,7 +223,7 @@ impl Derivable for CheckedBitPattern { } } - fn asserts(input: &DeriveInput) -> Result { + fn asserts(input: &DeriveInput, crate_name: &TokenStream) -> Result { if !input.generics.params.is_empty() { bail!("CheckedBitPattern cannot be derived for structs containing generic parameters"); } @@ -231,7 +231,7 @@ impl Derivable for CheckedBitPattern { match &input.data { Data::Struct(DataStruct { .. }) => { let assert_fields_are_maybe_pod = - generate_fields_are_trait(&input, Self::ident(input)?)?; + generate_fields_are_trait(&input, Self::ident(input, crate_name)?)?; Ok(assert_fields_are_maybe_pod) } @@ -240,13 +240,13 @@ impl Derivable for CheckedBitPattern { } } - fn trait_impl(input: &DeriveInput) -> Result<(TokenStream, TokenStream)> { + fn trait_impl(input: &DeriveInput, crate_name: &TokenStream) -> Result<(TokenStream, TokenStream)> { match &input.data { Data::Struct(DataStruct { fields, .. }) => { - generate_checked_bit_pattern_struct(&input.ident, fields, &input.attrs) + generate_checked_bit_pattern_struct(&input.ident, fields, &input.attrs, crate_name) } Data::Enum(DataEnum { variants, .. }) => { - generate_checked_bit_pattern_enum(input, variants) + generate_checked_bit_pattern_enum(input, variants, crate_name) } Data::Union(_) => bail!("Internal error in CheckedBitPattern derive"), /* shouldn't be possible since we already error in attribute check for this case */ } @@ -274,7 +274,7 @@ impl TransparentWrapper { } impl Derivable for TransparentWrapper { - fn ident(input: &DeriveInput) -> Result { + fn ident(input: &DeriveInput, crate_name: &TokenStream) -> Result { let fields = get_struct_fields(input)?; let ty = match Self::get_wrapper_type(&input.attrs, &fields) { @@ -287,10 +287,10 @@ impl Derivable for TransparentWrapper { ), }; - Ok(syn::parse_quote!(::bytemuck::TransparentWrapper<#ty>)) + Ok(syn::parse_quote!(#crate_name::TransparentWrapper<#ty>)) } - fn asserts(input: &DeriveInput) -> Result { + fn asserts(input: &DeriveInput, crate_name: &TokenStream) -> Result { let (impl_generics, _ty_generics, where_clause) = input.generics.split_for_impl(); let fields = get_struct_fields(input)?; @@ -318,7 +318,7 @@ impl Derivable for TransparentWrapper { const _: () = { #[repr(transparent)] struct AssertWrappedIsWrapped #impl_generics((u8, ::core::marker::PhantomData<#wrapped_field_ty>), #(#nonwrapped_field_tys),*) #where_clause; - fn assert_zeroable() {} + fn assert_zeroable() {} fn check #impl_generics () #where_clause { #( assert_zeroable::<#nonwrapped_field_tys>(); @@ -352,11 +352,11 @@ impl Derivable for TransparentWrapper { pub struct Contiguous; impl Derivable for Contiguous { - fn ident(_: &DeriveInput) -> Result { - Ok(syn::parse_quote!(::bytemuck::Contiguous)) + fn ident(_: &DeriveInput, crate_name: &TokenStream) -> Result { + Ok(syn::parse_quote!(#crate_name::Contiguous)) } - fn trait_impl(input: &DeriveInput) -> Result<(TokenStream, TokenStream)> { + fn trait_impl(input: &DeriveInput, _crate_name: &TokenStream) -> Result<(TokenStream, TokenStream)> { let repr = get_repr(&input.attrs)?; let integer_ty = if let Some(integer_ty) = repr.repr.as_integer() { @@ -460,7 +460,7 @@ fn get_field_types<'a>( } fn generate_checked_bit_pattern_struct( - input_ident: &Ident, fields: &Fields, attrs: &[Attribute], + input_ident: &Ident, fields: &Fields, attrs: &[Attribute], crate_name: &TokenStream ) -> Result<(TokenStream, TokenStream)> { let bits_ty = Ident::new(&format!("{}Bits", input_ident), input_ident.span()); @@ -486,10 +486,10 @@ fn generate_checked_bit_pattern_struct( Ok(( quote! { #repr - #[derive(Clone, Copy, ::bytemuck::AnyBitPattern)] + #[derive(Clone, Copy, #crate_name::AnyBitPattern)] #derive_dbg pub struct #bits_ty { - #(#field_name: <#field_ty as ::bytemuck::CheckedBitPattern>::Bits,)* + #(#field_name: <#field_ty as #crate_name::CheckedBitPattern>::Bits,)* } }, quote! { @@ -498,17 +498,17 @@ fn generate_checked_bit_pattern_struct( #[inline] #[allow(clippy::double_comparisons)] fn is_valid_bit_pattern(bits: &#bits_ty) -> bool { - #(<#field_ty as ::bytemuck::CheckedBitPattern>::is_valid_bit_pattern(&{ bits.#field_name }) && )* true + #(<#field_ty as #crate_name::CheckedBitPattern>::is_valid_bit_pattern(&{ bits.#field_name }) && )* true } }, )) } fn generate_checked_bit_pattern_enum( - input: &DeriveInput, variants: &Punctuated, + input: &DeriveInput, variants: &Punctuated, crate_name: &TokenStream ) -> Result<(TokenStream, TokenStream)> { if enum_has_fields(variants.iter()) { - generate_checked_bit_pattern_enum_with_fields(input, variants) + generate_checked_bit_pattern_enum_with_fields(input, variants, crate_name) } else { generate_checked_bit_pattern_enum_without_fields(input, variants) } @@ -574,7 +574,7 @@ fn generate_checked_bit_pattern_enum_without_fields( } fn generate_checked_bit_pattern_enum_with_fields( - input: &DeriveInput, variants: &Punctuated, + input: &DeriveInput, variants: &Punctuated, crate_name: &TokenStream ) -> Result<(TokenStream, TokenStream)> { let representation = get_repr(&input.attrs)?; let vis = &input.vis; @@ -617,7 +617,7 @@ fn generate_checked_bit_pattern_enum_with_fields( let fields = v.fields.iter().map(|v| &v.ty); quote! { - #[derive(::core::clone::Clone, ::core::marker::Copy, ::bytemuck::CheckedBitPattern)] + #[derive(::core::clone::Clone, ::core::marker::Copy, #crate_name::CheckedBitPattern)] #[repr(C)] #vis struct #variant_struct_ident(#(#fields),*); } @@ -644,7 +644,7 @@ fn generate_checked_bit_pattern_enum_with_fields( Ok(quote! { #discriminant => { let payload = unsafe { &bits.payload.#ident }; - <#variant_struct_ident as ::bytemuck::CheckedBitPattern>::is_valid_bit_pattern(payload) + <#variant_struct_ident as #crate_name::CheckedBitPattern>::is_valid_bit_pattern(payload) } }) }) @@ -652,7 +652,7 @@ fn generate_checked_bit_pattern_enum_with_fields( Ok(( quote! { - #[derive(::core::clone::Clone, ::core::marker::Copy, ::bytemuck::AnyBitPattern)] + #[derive(::core::clone::Clone, ::core::marker::Copy, #crate_name::AnyBitPattern)] #derive_dbg #bits_repr #vis struct #bits_ty_ident { @@ -660,7 +660,7 @@ fn generate_checked_bit_pattern_enum_with_fields( payload: #variants_union_ident, } - #[derive(::core::clone::Clone, ::core::marker::Copy, ::bytemuck::AnyBitPattern)] + #[derive(::core::clone::Clone, ::core::marker::Copy, #crate_name::AnyBitPattern)] #[repr(C)] #[allow(non_snake_case)] #vis union #variants_union_ident { @@ -703,17 +703,17 @@ fn generate_checked_bit_pattern_enum_with_fields( Ok(( quote! { - #[derive(::core::clone::Clone, ::core::marker::Copy, ::bytemuck::CheckedBitPattern)] + #[derive(::core::clone::Clone, ::core::marker::Copy, #crate_name::CheckedBitPattern)] #[repr(C)] #vis struct #bits_ty(#(#fields),*); }, quote! { - type Bits = <#bits_ty as ::bytemuck::CheckedBitPattern>::Bits; + type Bits = <#bits_ty as #crate_name::CheckedBitPattern>::Bits; #[inline] #[allow(clippy::double_comparisons)] fn is_valid_bit_pattern(bits: &Self::Bits) -> bool { - <#bits_ty as ::bytemuck::CheckedBitPattern>::is_valid_bit_pattern(bits) + <#bits_ty as #crate_name::CheckedBitPattern>::is_valid_bit_pattern(bits) } }, )) @@ -740,7 +740,7 @@ fn generate_checked_bit_pattern_enum_with_fields( // adding the discriminant repr integer as first field, as described above quote! { - #[derive(::core::clone::Clone, ::core::marker::Copy, ::bytemuck::CheckedBitPattern)] + #[derive(::core::clone::Clone, ::core::marker::Copy, #crate_name::CheckedBitPattern)] #[repr(C)] #vis struct #variant_struct_ident(#integer, #(#fields),*); } @@ -767,7 +767,7 @@ fn generate_checked_bit_pattern_enum_with_fields( Ok(quote! { #discriminant => { let payload = unsafe { &bits.#ident }; - <#variant_struct_ident as ::bytemuck::CheckedBitPattern>::is_valid_bit_pattern(payload) + <#variant_struct_ident as #crate_name::CheckedBitPattern>::is_valid_bit_pattern(payload) } }) }) @@ -775,7 +775,7 @@ fn generate_checked_bit_pattern_enum_with_fields( Ok(( quote! { - #[derive(::core::clone::Clone, ::core::marker::Copy, ::bytemuck::AnyBitPattern)] + #[derive(::core::clone::Clone, ::core::marker::Copy, #crate_name::AnyBitPattern)] #bits_repr #[allow(non_snake_case)] #vis union #bits_ty_ident { @@ -1219,3 +1219,47 @@ mod tests { ); } } + +pub fn bytemuck_crate_name(input: &DeriveInput) -> TokenStream { + const ATTR_NAME: &'static str = "crate"; + + let mut crate_name = quote!(::bytemuck); + for attr in &input.attrs { + if !attr.path().is_ident("bytemuck") { + continue; + } + + attr.parse_nested_meta(|meta| { + if meta.path.is_ident(ATTR_NAME) { + let expr: syn::Expr = meta.value()?.parse()?; + let mut value = &expr; + while let syn::Expr::Group(e) = value { + value = &e.expr; + } + if let syn::Expr::Lit(syn::ExprLit { + lit: syn::Lit::Str(lit), .. + }) = value + { + let suffix = lit.suffix(); + if !suffix.is_empty() { + bail!(format!("Unexpected suffix `{}` on string literal", suffix)) + } + let path: syn::Path = match lit.parse() { + Ok(path) => path, + Err(_) => { + bail!(format!("Failed to parse path: {:?}", lit.value())) + } + }; + crate_name = path.into_token_stream(); + } else { + bail!( + "Expected bytemuck `crate` attribute to be a string: `crate = \"...\"`", + ) + } + } + Ok(()) + }).unwrap(); + } + + return crate_name; +} diff --git a/derive/tests/basic.rs b/derive/tests/basic.rs index 5e2797e..d3d589d 100644 --- a/derive/tests/basic.rs +++ b/derive/tests/basic.rs @@ -443,3 +443,10 @@ fn checkedbitpattern_transparent_enum_with_fields() { #[derive(Copy, Clone, bytemuck::Pod, bytemuck::Zeroable)] #[repr(C, align(16))] struct Issue127 {} + +use bytemuck as reexport_name; +#[derive(Copy, Clone, bytemuck::Pod, bytemuck::Zeroable, bytemuck::ByteEq)] +#[bytemuck(crate = "reexport_name")] +#[repr(C)] +struct Issue93 {} +