From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- rust/macros/helpers.rs | 155 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 155 insertions(+) create mode 100644 rust/macros/helpers.rs (limited to 'rust/macros/helpers.rs') diff --git a/rust/macros/helpers.rs b/rust/macros/helpers.rs new file mode 100644 index 0000000000..afb0f2e3a3 --- /dev/null +++ b/rust/macros/helpers.rs @@ -0,0 +1,155 @@ +// SPDX-License-Identifier: GPL-2.0 + +use proc_macro::{token_stream, Group, Punct, Spacing, TokenStream, TokenTree}; + +pub(crate) fn try_ident(it: &mut token_stream::IntoIter) -> Option { + if let Some(TokenTree::Ident(ident)) = it.next() { + Some(ident.to_string()) + } else { + None + } +} + +pub(crate) fn try_literal(it: &mut token_stream::IntoIter) -> Option { + if let Some(TokenTree::Literal(literal)) = it.next() { + Some(literal.to_string()) + } else { + None + } +} + +pub(crate) fn try_string(it: &mut token_stream::IntoIter) -> Option { + try_literal(it).and_then(|string| { + if string.starts_with('\"') && string.ends_with('\"') { + let content = &string[1..string.len() - 1]; + if content.contains('\\') { + panic!("Escape sequences in string literals not yet handled"); + } + Some(content.to_string()) + } else if string.starts_with("r\"") { + panic!("Raw string literals are not yet handled"); + } else { + None + } + }) +} + +pub(crate) fn expect_ident(it: &mut token_stream::IntoIter) -> String { + try_ident(it).expect("Expected Ident") +} + +pub(crate) fn expect_punct(it: &mut token_stream::IntoIter) -> char { + if let TokenTree::Punct(punct) = it.next().expect("Reached end of token stream for Punct") { + punct.as_char() + } else { + panic!("Expected Punct"); + } +} + +pub(crate) fn expect_string(it: &mut token_stream::IntoIter) -> String { + try_string(it).expect("Expected string") +} + +pub(crate) fn expect_string_ascii(it: &mut token_stream::IntoIter) -> String { + let string = try_string(it).expect("Expected string"); + assert!(string.is_ascii(), "Expected ASCII string"); + string +} + +pub(crate) fn expect_group(it: &mut token_stream::IntoIter) -> Group { + if let TokenTree::Group(group) = it.next().expect("Reached end of token stream for Group") { + group + } else { + panic!("Expected Group"); + } +} + +pub(crate) fn expect_end(it: &mut token_stream::IntoIter) { + if it.next().is_some() { + panic!("Expected end"); + } +} + +pub(crate) struct Generics { + pub(crate) impl_generics: Vec, + pub(crate) ty_generics: Vec, +} + +/// 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) { + // `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; + for tt in &mut toks { + match tt.clone() { + TokenTree::Punct(p) if p.as_char() == '<' => { + if nesting >= 1 { + // 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 { + // We are still inside of the generics and part of some bound. + impl_generics.push(tt); + } + if nesting == 0 { + break; + } + } + } + tt => { + if nesting == 1 { + // Here depending on the token, it might be a generic variable name. + match &tt { + // Ignore const. + TokenTree::Ident(i) if i.to_string() == "const" => {} + TokenTree::Ident(_) if at_start => { + ty_generics.push(tt.clone()); + // We also already push the `,` token, this makes it easier to append + // generics. + ty_generics.push(TokenTree::Punct(Punct::new(',', Spacing::Alone))); + at_start = false; + } + TokenTree::Punct(p) if p.as_char() == ',' => at_start = true, + // Lifetimes begin with `'`. + TokenTree::Punct(p) if p.as_char() == '\'' && at_start => { + ty_generics.push(tt.clone()); + } + _ => {} + } + } + if nesting >= 1 { + impl_generics.push(tt); + } else if nesting == 0 { + // If we haven't entered the generics yet, we still want to keep these tokens. + rest.push(tt); + } + } + } + } + rest.extend(toks); + ( + Generics { + impl_generics, + ty_generics, + }, + rest, + ) +} -- cgit v1.2.3