mirror of https://github.com/torvalds/linux.git
53 lines
1.1 KiB
Rust
53 lines
1.1 KiB
Rust
// SPDX-License-Identifier: Apache-2.0 OR MIT
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use crate::ToTokens;
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use proc_macro2::extra::DelimSpan;
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use proc_macro2::{Span, TokenStream};
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// Not public API other than via the syn crate. Use syn::spanned::Spanned.
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pub trait Spanned: private::Sealed {
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fn __span(&self) -> Span;
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}
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impl Spanned for Span {
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fn __span(&self) -> Span {
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*self
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}
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}
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impl Spanned for DelimSpan {
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fn __span(&self) -> Span {
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self.join()
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}
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}
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impl<T: ?Sized + ToTokens> Spanned for T {
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fn __span(&self) -> Span {
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join_spans(self.into_token_stream())
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}
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}
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fn join_spans(tokens: TokenStream) -> Span {
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let mut iter = tokens.into_iter().map(|tt| tt.span());
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let first = match iter.next() {
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Some(span) => span,
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None => return Span::call_site(),
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};
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iter.fold(None, |_prev, next| Some(next))
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.and_then(|last| first.join(last))
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.unwrap_or(first)
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}
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mod private {
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use crate::ToTokens;
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use proc_macro2::extra::DelimSpan;
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use proc_macro2::Span;
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pub trait Sealed {}
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impl Sealed for Span {}
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impl Sealed for DelimSpan {}
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impl<T: ?Sized + ToTokens> Sealed for T {}
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}
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