diff options
Diffstat (limited to 'rust/macros/quote.rs')
| -rw-r--r-- | rust/macros/quote.rs | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/rust/macros/quote.rs b/rust/macros/quote.rs new file mode 100644 index 0000000000..33a199e4f1 --- /dev/null +++ b/rust/macros/quote.rs @@ -0,0 +1,157 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + +use proc_macro::{TokenStream, TokenTree}; + +pub(crate) trait ToTokens { + fn to_tokens(&self, tokens: &mut TokenStream); +} + +impl<T: ToTokens> ToTokens for Option<T> { + fn to_tokens(&self, tokens: &mut TokenStream) { + if let Some(v) = self { + v.to_tokens(tokens); + } + } +} + +impl ToTokens for proc_macro::Group { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.extend([TokenTree::from(self.clone())]); + } +} + +impl ToTokens for TokenTree { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.extend([self.clone()]); + } +} + +impl ToTokens for TokenStream { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.extend(self.clone()); + } +} + +/// Converts tokens into [`proc_macro::TokenStream`] and performs variable interpolations with +/// the given span. +/// +/// This is a similar to the +/// [`quote_spanned!`](https://docs.rs/quote/latest/quote/macro.quote_spanned.html) macro from the +/// `quote` crate but provides only just enough functionality needed by the current `macros` crate. +macro_rules! quote_spanned { + ($span:expr => $($tt:tt)*) => {{ + let mut tokens; + #[allow(clippy::vec_init_then_push)] + { + tokens = ::std::vec::Vec::new(); + let span = $span; + quote_spanned!(@proc tokens span $($tt)*); + } + ::proc_macro::TokenStream::from_iter(tokens) + }}; + (@proc $v:ident $span:ident) => {}; + (@proc $v:ident $span:ident #$id:ident $($tt:tt)*) => { + let mut ts = ::proc_macro::TokenStream::new(); + $crate::quote::ToTokens::to_tokens(&$id, &mut ts); + $v.extend(ts); + quote_spanned!(@proc $v $span $($tt)*); + }; + (@proc $v:ident $span:ident #(#$id:ident)* $($tt:tt)*) => { + for token in $id { + let mut ts = ::proc_macro::TokenStream::new(); + $crate::quote::ToTokens::to_tokens(&token, &mut ts); + $v.extend(ts); + } + quote_spanned!(@proc $v $span $($tt)*); + }; + (@proc $v:ident $span:ident ( $($inner:tt)* ) $($tt:tt)*) => { + let mut tokens = ::std::vec::Vec::new(); + quote_spanned!(@proc tokens $span $($inner)*); + $v.push(::proc_macro::TokenTree::Group(::proc_macro::Group::new( + ::proc_macro::Delimiter::Parenthesis, + ::proc_macro::TokenStream::from_iter(tokens) + ))); + quote_spanned!(@proc $v $span $($tt)*); + }; + (@proc $v:ident $span:ident [ $($inner:tt)* ] $($tt:tt)*) => { + let mut tokens = ::std::vec::Vec::new(); + quote_spanned!(@proc tokens $span $($inner)*); + $v.push(::proc_macro::TokenTree::Group(::proc_macro::Group::new( + ::proc_macro::Delimiter::Bracket, + ::proc_macro::TokenStream::from_iter(tokens) + ))); + quote_spanned!(@proc $v $span $($tt)*); + }; + (@proc $v:ident $span:ident { $($inner:tt)* } $($tt:tt)*) => { + let mut tokens = ::std::vec::Vec::new(); + quote_spanned!(@proc tokens $span $($inner)*); + $v.push(::proc_macro::TokenTree::Group(::proc_macro::Group::new( + ::proc_macro::Delimiter::Brace, + ::proc_macro::TokenStream::from_iter(tokens) + ))); + quote_spanned!(@proc $v $span $($tt)*); + }; + (@proc $v:ident $span:ident :: $($tt:tt)*) => { + $v.push(::proc_macro::TokenTree::Punct( + ::proc_macro::Punct::new(':', ::proc_macro::Spacing::Joint) + )); + $v.push(::proc_macro::TokenTree::Punct( + ::proc_macro::Punct::new(':', ::proc_macro::Spacing::Alone) + )); + quote_spanned!(@proc $v $span $($tt)*); + }; + (@proc $v:ident $span:ident : $($tt:tt)*) => { + $v.push(::proc_macro::TokenTree::Punct( + ::proc_macro::Punct::new(':', ::proc_macro::Spacing::Alone) + )); + quote_spanned!(@proc $v $span $($tt)*); + }; + (@proc $v:ident $span:ident , $($tt:tt)*) => { + $v.push(::proc_macro::TokenTree::Punct( + ::proc_macro::Punct::new(',', ::proc_macro::Spacing::Alone) + )); + quote_spanned!(@proc $v $span $($tt)*); + }; + (@proc $v:ident $span:ident @ $($tt:tt)*) => { + $v.push(::proc_macro::TokenTree::Punct( + ::proc_macro::Punct::new('@', ::proc_macro::Spacing::Alone) + )); + quote_spanned!(@proc $v $span $($tt)*); + }; + (@proc $v:ident $span:ident ! $($tt:tt)*) => { + $v.push(::proc_macro::TokenTree::Punct( + ::proc_macro::Punct::new('!', ::proc_macro::Spacing::Alone) + )); + quote_spanned!(@proc $v $span $($tt)*); + }; + (@proc $v:ident $span:ident ; $($tt:tt)*) => { + $v.push(::proc_macro::TokenTree::Punct( + ::proc_macro::Punct::new(';', ::proc_macro::Spacing::Alone) + )); + quote_spanned!(@proc $v $span $($tt)*); + }; + (@proc $v:ident $span:ident + $($tt:tt)*) => { + $v.push(::proc_macro::TokenTree::Punct( + ::proc_macro::Punct::new('+', ::proc_macro::Spacing::Alone) + )); + quote_spanned!(@proc $v $span $($tt)*); + }; + (@proc $v:ident $span:ident $id:ident $($tt:tt)*) => { + $v.push(::proc_macro::TokenTree::Ident(::proc_macro::Ident::new(stringify!($id), $span))); + quote_spanned!(@proc $v $span $($tt)*); + }; +} + +/// Converts tokens into [`proc_macro::TokenStream`] and performs variable interpolations with +/// mixed site span ([`Span::mixed_site()`]). +/// +/// This is a similar to the [`quote!`](https://docs.rs/quote/latest/quote/macro.quote.html) macro +/// from the `quote` crate but provides only just enough functionality needed by the current +/// `macros` crate. +/// +/// [`Span::mixed_site()`]: https://doc.rust-lang.org/proc_macro/struct.Span.html#method.mixed_site +macro_rules! quote { + ($($tt:tt)*) => { + quote_spanned!(::proc_macro::Span::mixed_site() => $($tt)*) + } +} |