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-rw-r--r--rust/macros/quote.rs157
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)*)
+ }
+}