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| 1 | +use proc_macro::TokenStream; |
| 2 | +use proc_macro_crate::{FoundCrate, crate_name}; |
| 3 | +use quote::{format_ident, quote}; |
| 4 | +use syn::{ |
| 5 | + Data, DataStruct, DeriveInput, Error, Field, Ident, LitInt, WhereClause, parse_macro_input, |
| 6 | + parse_quote, |
| 7 | +}; |
| 8 | + |
| 9 | +fn find_oneapi() -> Ident { |
| 10 | + let crate_name = |
| 11 | + crate_name("oneapi-rs").expect("Expected oneapi-rs to be present in Cargo.toml"); |
| 12 | + match crate_name { |
| 13 | + FoundCrate::Itself => format_ident!("oneapi_rs"), |
| 14 | + FoundCrate::Name(name) => format_ident!("{name}"), |
| 15 | + } |
| 16 | +} |
| 17 | + |
| 18 | +/// Derive macro generating an impl of the `KernelArgumentList` trait for a given struct. |
| 19 | +#[proc_macro_derive(KernelArgumentList)] |
| 20 | +pub fn derive_kernel_argument_list(input: TokenStream) -> TokenStream { |
| 21 | + let mut input = parse_macro_input!(input as DeriveInput); |
| 22 | + let oneapi = find_oneapi(); |
| 23 | + |
| 24 | + let Data::Struct(data) = &input.data else { |
| 25 | + return Error::new_spanned(input, "This derive macro only works on structs.") |
| 26 | + .into_compile_error() |
| 27 | + .into(); |
| 28 | + }; |
| 29 | + expand_where_clause(input.generics.make_where_clause(), data, &oneapi); |
| 30 | + let (impl_generics, ty_generics, where_clause) = input.generics.split_for_impl(); |
| 31 | + |
| 32 | + let ident = input.ident; |
| 33 | + let argc = data.fields.len(); |
| 34 | + let members = data.fields.members(); |
| 35 | + |
| 36 | + let expanded = quote! { |
| 37 | + unsafe impl #impl_generics #oneapi::kernel::KernelArgumentList<#argc> |
| 38 | + for #ident #ty_generics #where_clause { |
| 39 | + unsafe fn as_raw_arg_list(&self) -> [&[u8]; #argc] { |
| 40 | + [ #(unsafe { self.#members.as_raw_arg() }),* ] |
| 41 | + } |
| 42 | + } |
| 43 | + }; |
| 44 | + |
| 45 | + TokenStream::from(expanded) |
| 46 | +} |
| 47 | + |
| 48 | +fn expand_where_clause(where_clause: &mut WhereClause, data: &DataStruct, oneapi: &Ident) { |
| 49 | + for Field { ty, .. } in &data.fields { |
| 50 | + where_clause |
| 51 | + .predicates |
| 52 | + .push(parse_quote!(#ty: #oneapi::kernel::KernelArgument)); |
| 53 | + } |
| 54 | +} |
| 55 | + |
| 56 | +fn get_single_tuple_impl(argc: usize) -> proc_macro2::TokenStream { |
| 57 | + let iter = { 0..argc }.map(syn::Index::from); |
| 58 | + let types = { 0..argc } |
| 59 | + .map(|i| format_ident!("T{i}")) |
| 60 | + .collect::<Vec<_>>(); |
| 61 | + |
| 62 | + quote! { |
| 63 | + unsafe impl<#(#types),*> crate::kernel::KernelArgumentList<#argc> for (#(#types),*) |
| 64 | + where #(#types: crate::kernel::KernelArgument),* { |
| 65 | + unsafe fn as_raw_arg_list(&self) -> [&[u8]; #argc] { |
| 66 | + [ #(unsafe { self.#iter.as_raw_arg() }),* ] |
| 67 | + } |
| 68 | + } |
| 69 | + } |
| 70 | +} |
| 71 | + |
| 72 | +/// A macro that generates tuples from 2..N which implement the `KernelArgumentList` trait. |
| 73 | +#[proc_macro] |
| 74 | +pub fn impl_arg_list_for_tuples(input: TokenStream) -> TokenStream { |
| 75 | + let input = parse_macro_input!(input as LitInt); |
| 76 | + let argc = input.base10_parse::<usize>().unwrap(); |
| 77 | + |
| 78 | + let impls = { 2..=argc }.map(get_single_tuple_impl); |
| 79 | + |
| 80 | + let expanded = quote! { |
| 81 | + #(#impls)* |
| 82 | + }; |
| 83 | + |
| 84 | + TokenStream::from(expanded) |
| 85 | +} |
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