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-rw-r--r--rust/macros/helpers.rs153
1 files changed, 12 insertions, 141 deletions
diff --git a/rust/macros/helpers.rs b/rust/macros/helpers.rs
index 563dcd2b7ace..a3ee27e29a6f 100644
--- a/rust/macros/helpers.rs
+++ b/rust/macros/helpers.rs
@@ -1,6 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
-use proc_macro::{token_stream, Group, TokenStream, TokenTree};
+use proc_macro::{token_stream, Group, Ident, TokenStream, TokenTree};
pub(crate) fn try_ident(it: &mut token_stream::IntoIter) -> Option<String> {
if let Some(TokenTree::Ident(ident)) = it.next() {
@@ -70,148 +70,19 @@ pub(crate) fn expect_end(it: &mut token_stream::IntoIter) {
}
}
-/// Parsed generics.
-///
-/// See the field documentation for an explanation what each of the fields represents.
-///
-/// # Examples
-///
-/// ```rust,ignore
-/// # let input = todo!();
-/// let (Generics { decl_generics, impl_generics, ty_generics }, rest) = parse_generics(input);
-/// quote! {
-/// struct Foo<$($decl_generics)*> {
-/// // ...
-/// }
-///
-/// impl<$impl_generics> Foo<$ty_generics> {
-/// fn foo() {
-/// // ...
-/// }
-/// }
-/// }
-/// ```
-pub(crate) struct Generics {
- /// The generics with bounds and default values (e.g. `T: Clone, const N: usize = 0`).
- ///
- /// Use this on type definitions e.g. `struct Foo<$decl_generics> ...` (or `union`/`enum`).
- pub(crate) decl_generics: Vec<TokenTree>,
- /// The generics with bounds (e.g. `T: Clone, const N: usize`).
- ///
- /// Use this on `impl` blocks e.g. `impl<$impl_generics> Trait for ...`.
- pub(crate) impl_generics: Vec<TokenTree>,
- /// The generics without bounds and without default values (e.g. `T, N`).
- ///
- /// Use this when you use the type that is declared with these generics e.g.
- /// `Foo<$ty_generics>`.
- pub(crate) ty_generics: Vec<TokenTree>,
-}
-
-/// Parses the given `TokenStream` into `Generics` and the rest.
-///
-/// The generics are not present in the rest, but a where clause might remain.
-pub(crate) fn parse_generics(input: TokenStream) -> (Generics, Vec<TokenTree>) {
- // The generics with bounds and default values.
- let mut decl_generics = vec![];
- // `impl_generics`, the declared generics with their bounds.
- let mut impl_generics = vec![];
- // Only the names of the generics, without any bounds.
- let mut ty_generics = vec![];
- // Tokens not related to the generics e.g. the `where` token and definition.
- let mut rest = vec![];
- // The current level of `<`.
- let mut nesting = 0;
- let mut toks = input.into_iter();
- // If we are at the beginning of a generic parameter.
- let mut at_start = true;
- let mut skip_until_comma = false;
- while let Some(tt) = toks.next() {
- if nesting == 1 && matches!(&tt, TokenTree::Punct(p) if p.as_char() == '>') {
- // Found the end of the generics.
- break;
- } else if nesting >= 1 {
- decl_generics.push(tt.clone());
- }
- match tt.clone() {
- TokenTree::Punct(p) if p.as_char() == '<' => {
- if nesting >= 1 && !skip_until_comma {
- // This is inside of the generics and part of some bound.
- impl_generics.push(tt);
- }
- nesting += 1;
- }
- TokenTree::Punct(p) if p.as_char() == '>' => {
- // This is a parsing error, so we just end it here.
- if nesting == 0 {
- break;
- } else {
- nesting -= 1;
- if nesting >= 1 && !skip_until_comma {
- // We are still inside of the generics and part of some bound.
- impl_generics.push(tt);
- }
- }
- }
- TokenTree::Punct(p) if skip_until_comma && p.as_char() == ',' => {
- if nesting == 1 {
- impl_generics.push(tt.clone());
- impl_generics.push(tt);
- skip_until_comma = false;
- }
- }
- _ if !skip_until_comma => {
- match nesting {
- // If we haven't entered the generics yet, we still want to keep these tokens.
- 0 => rest.push(tt),
- 1 => {
- // Here depending on the token, it might be a generic variable name.
- match tt.clone() {
- TokenTree::Ident(i) if at_start && i.to_string() == "const" => {
- let Some(name) = toks.next() else {
- // Parsing error.
- break;
- };
- impl_generics.push(tt);
- impl_generics.push(name.clone());
- ty_generics.push(name.clone());
- decl_generics.push(name);
- at_start = false;
- }
- TokenTree::Ident(_) if at_start => {
- impl_generics.push(tt.clone());
- ty_generics.push(tt);
- at_start = false;
- }
- TokenTree::Punct(p) if p.as_char() == ',' => {
- impl_generics.push(tt.clone());
- ty_generics.push(tt);
- at_start = true;
- }
- // Lifetimes begin with `'`.
- TokenTree::Punct(p) if p.as_char() == '\'' && at_start => {
- impl_generics.push(tt.clone());
- ty_generics.push(tt);
- }
- // Generics can have default values, we skip these.
- TokenTree::Punct(p) if p.as_char() == '=' => {
- skip_until_comma = true;
- }
- _ => impl_generics.push(tt),
- }
- }
- _ => impl_generics.push(tt),
+/// Given a function declaration, finds the name of the function.
+pub(crate) fn function_name(input: TokenStream) -> Option<Ident> {
+ let mut input = input.into_iter();
+ while let Some(token) = input.next() {
+ match token {
+ TokenTree::Ident(i) if i.to_string() == "fn" => {
+ if let Some(TokenTree::Ident(i)) = input.next() {
+ return Some(i);
}
+ return None;
}
- _ => {}
+ _ => continue,
}
}
- rest.extend(toks);
- (
- Generics {
- impl_generics,
- decl_generics,
- ty_generics,
- },
- rest,
- )
+ None
}