diff options
author | Johannes Berg <johannes.berg@intel.com> | 2023-10-05 22:57:34 +0200 |
---|---|---|
committer | Kalle Valo <kvalo@kernel.org> | 2023-10-06 17:08:47 +0300 |
commit | 7d6904bf26b96ef087514cb7a8c50b62a4911c99 (patch) | |
tree | 2feaff8495d88c2102dc2e017b7afc5c58db02d6 /rust/macros/paste.rs | |
parent | 9418edf8ff01e7a4904aac1aca4864ecdea37593 (diff) | |
parent | 22061bfc57fe08c77141dc876b4af75603c4d61d (diff) |
Merge wireless into wireless-next
Resolve several conflicts, mostly between changes/fixes in
wireless and the locking rework in wireless-next. One of
the conflicts actually shows a bug in wireless that we'll
want to fix separately.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Diffstat (limited to 'rust/macros/paste.rs')
-rw-r--r-- | rust/macros/paste.rs | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/rust/macros/paste.rs b/rust/macros/paste.rs new file mode 100644 index 000000000000..385a78434224 --- /dev/null +++ b/rust/macros/paste.rs @@ -0,0 +1,96 @@ +// SPDX-License-Identifier: GPL-2.0 + +use proc_macro::{Delimiter, Group, Ident, Spacing, Span, TokenTree}; + +fn concat(tokens: &[TokenTree], group_span: Span) -> TokenTree { + let mut tokens = tokens.iter(); + let mut segments = Vec::new(); + let mut span = None; + loop { + match tokens.next() { + None => break, + Some(TokenTree::Literal(lit)) => segments.push((lit.to_string(), lit.span())), + Some(TokenTree::Ident(ident)) => { + let mut value = ident.to_string(); + if value.starts_with("r#") { + value.replace_range(0..2, ""); + } + segments.push((value, ident.span())); + } + Some(TokenTree::Punct(p)) if p.as_char() == ':' => { + let Some(TokenTree::Ident(ident)) = tokens.next() else { + panic!("expected identifier as modifier"); + }; + + let (mut value, sp) = segments.pop().expect("expected identifier before modifier"); + match ident.to_string().as_str() { + // Set the overall span of concatenated token as current span + "span" => { + assert!( + span.is_none(), + "span modifier should only appear at most once" + ); + span = Some(sp); + } + "lower" => value = value.to_lowercase(), + "upper" => value = value.to_uppercase(), + v => panic!("unknown modifier `{v}`"), + }; + segments.push((value, sp)); + } + _ => panic!("unexpected token in paste segments"), + }; + } + + let pasted: String = segments.into_iter().map(|x| x.0).collect(); + TokenTree::Ident(Ident::new(&pasted, span.unwrap_or(group_span))) +} + +pub(crate) fn expand(tokens: &mut Vec<TokenTree>) { + for token in tokens.iter_mut() { + if let TokenTree::Group(group) = token { + let delimiter = group.delimiter(); + let span = group.span(); + let mut stream: Vec<_> = group.stream().into_iter().collect(); + // Find groups that looks like `[< A B C D >]` + if delimiter == Delimiter::Bracket + && stream.len() >= 3 + && matches!(&stream[0], TokenTree::Punct(p) if p.as_char() == '<') + && matches!(&stream[stream.len() - 1], TokenTree::Punct(p) if p.as_char() == '>') + { + // Replace the group with concatenated token + *token = concat(&stream[1..stream.len() - 1], span); + } else { + // Recursively expand tokens inside the group + expand(&mut stream); + let mut group = Group::new(delimiter, stream.into_iter().collect()); + group.set_span(span); + *token = TokenTree::Group(group); + } + } + } + + // Path segments cannot contain invisible delimiter group, so remove them if any. + for i in (0..tokens.len().saturating_sub(3)).rev() { + // Looking for a double colon + if matches!( + (&tokens[i + 1], &tokens[i + 2]), + (TokenTree::Punct(a), TokenTree::Punct(b)) + if a.as_char() == ':' && a.spacing() == Spacing::Joint && b.as_char() == ':' + ) { + match &tokens[i + 3] { + TokenTree::Group(group) if group.delimiter() == Delimiter::None => { + tokens.splice(i + 3..i + 4, group.stream()); + } + _ => (), + } + + match &tokens[i] { + TokenTree::Group(group) if group.delimiter() == Delimiter::None => { + tokens.splice(i..i + 1, group.stream()); + } + _ => (), + } + } + } +} |