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This commit is contained in:
Robin Appelman 2020-12-05 22:48:40 +01:00
commit 0c8d2ebe18
9 changed files with 195 additions and 167 deletions
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37
bitbuffer_derive/src/lib.rs
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@ -112,10 +112,10 @@
//! #
//! #[derive(BitRead)]
//! #[endianness = "E"]
//! struct EndiannessStruct<E: Endianness> {
//! struct EndiannessStruct<'a, E: Endianness> {
//! size: u8,
//! #[size = "size"]
//! stream: BitReadStream<E>,
//! stream: BitReadStream<'a, E>,
//! }
//! ```
//!
@ -125,10 +125,10 @@
//! #
//! #[derive(BitRead)]
//! #[endianness = "BigEndian"]
//! struct EndiannessStruct {
//! struct EndiannessStruct<'a> {
//! size: u8,
//! #[size = "size"]
//! stream: BitReadStream<BigEndian>,
//! stream: BitReadStream<'a, BigEndian>,
//! }
//! ```
extern crate proc_macro;
@ -138,7 +138,7 @@ use quote::{quote, quote_spanned};
use syn::spanned::Spanned;
use syn::{
parse_macro_input, parse_quote, parse_str, Attribute, Data, DataStruct, DeriveInput, Expr,
Fields, Ident, Lit, LitStr, Path, Variant,
Fields, GenericParam, Ident, Lit, LitStr, Path, Variant,
};
use syn_util::get_attribute_value;
@ -175,6 +175,18 @@ fn derive_bitread_trait(
let mut trait_generics = input.generics.clone();
// we need these separate generics to only add out Endianness param to the 'impl'
let (_, ty_generics, where_clause) = input.generics.split_for_impl();
let lifetime: Option<&GenericParam> = trait_generics
.params
.iter()
.filter(|param| matches!(param, GenericParam::Lifetime(_)))
.next();
let lifetime = match lifetime {
Some(GenericParam::Lifetime(lifetime)) => lifetime.lifetime.clone(),
_ => {
trait_generics.params.push(parse_quote!('a));
parse_quote!('a)
}
};
if endianness.is_none() {
trait_generics
.params
@ -193,7 +205,10 @@ fn derive_bitread_trait(
let parsed_unchecked = parse(input.data.clone(), &name, &input.attrs, true);
let endianness_placeholder = endianness.unwrap_or_else(|| "_E".to_owned());
let trait_def_str = format!("::bitbuffer::{}<{}>", trait_name, &endianness_placeholder);
let trait_def_str = format!(
"::bitbuffer::{}<{}, {}>",
trait_name, lifetime, &endianness_placeholder
);
let trait_def = parse_str::<Path>(&trait_def_str).unwrap();
let endianness_ident = Ident::new(&endianness_placeholder, span);
@ -218,10 +233,10 @@ fn derive_bitread_trait(
},
Span::call_site(),
);
//
let expanded = quote! {
impl #impl_generics #trait_def for #name #ty_generics #where_clause {
fn read(stream: &mut ::bitbuffer::BitReadStream<#endianness_ident>#extra_param) -> ::bitbuffer::Result<Self> {
fn read(stream: &mut ::bitbuffer::BitReadStream<#lifetime, #endianness_ident>#extra_param) -> ::bitbuffer::Result<Self> {
// if the read has a predicable size, we can do the bounds check in one go
match <Self as #trait_def>::#size_method_name(#extra_param_call) {
Some(size) => {
@ -236,7 +251,7 @@ fn derive_bitread_trait(
}
}
unsafe fn read_unchecked(stream: &mut ::bitbuffer::BitReadStream<#endianness_ident>#extra_param, end: bool) -> ::bitbuffer::Result<Self> {
unsafe fn read_unchecked(stream: &mut ::bitbuffer::BitReadStream<#lifetime, #endianness_ident>#extra_param, end: bool) -> ::bitbuffer::Result<Self> {
#parsed_unchecked
}
@ -410,12 +425,12 @@ fn size(data: Data, struct_name: &Ident, attrs: &[Attribute], has_input_size: bo
match size {
Some(size) => {
quote_spanned! { span =>
<#field_type as ::bitbuffer::BitReadSized<::bitbuffer::LittleEndian>>::bit_size_sized(#size)
<#field_type as ::bitbuffer::BitReadSized<'_, ::bitbuffer::LittleEndian>>::bit_size_sized(#size)
}
}
None => {
quote_spanned! { span =>
<#field_type as ::bitbuffer::BitRead<::bitbuffer::LittleEndian>>::bit_size()
<#field_type as ::bitbuffer::BitRead<'_, ::bitbuffer::LittleEndian>>::bit_size()
}
}
}