From 698f8c2f01ea549d77d7dc3338a12e04c11057b9 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Wed, 17 Apr 2024 14:02:58 +0200
Subject: Adding upstream version 1.64.0+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 vendor/proc-macro-error-attr/src/parse.rs | 89 +++++++++++++++++++++++++++++++
 1 file changed, 89 insertions(+)
 create mode 100644 vendor/proc-macro-error-attr/src/parse.rs

(limited to 'vendor/proc-macro-error-attr/src/parse.rs')

diff --git a/vendor/proc-macro-error-attr/src/parse.rs b/vendor/proc-macro-error-attr/src/parse.rs
new file mode 100644
index 000000000..6f4663f80
--- /dev/null
+++ b/vendor/proc-macro-error-attr/src/parse.rs
@@ -0,0 +1,89 @@
+use crate::{Error, Result};
+use proc_macro2::{Delimiter, Ident, Span, TokenStream, TokenTree};
+use quote::ToTokens;
+use std::iter::Peekable;
+
+pub(crate) fn parse_input(
+    input: TokenStream,
+) -> Result<(Vec<Attribute>, Vec<TokenTree>, TokenTree)> {
+    let mut input = input.into_iter().peekable();
+    let mut attrs = Vec::new();
+
+    while let Some(attr) = parse_next_attr(&mut input)? {
+        attrs.push(attr);
+    }
+
+    let sig = parse_signature(&mut input);
+    let body = input.next().ok_or_else(|| {
+        Error::new(
+            Span::call_site(),
+            "`#[proc_macro_error]` can be applied only to functions".to_string(),
+        )
+    })?;
+
+    Ok((attrs, sig, body))
+}
+
+fn parse_next_attr(
+    input: &mut Peekable<impl Iterator<Item = TokenTree>>,
+) -> Result<Option<Attribute>> {
+    let shebang = match input.peek() {
+        Some(TokenTree::Punct(ref punct)) if punct.as_char() == '#' => input.next().unwrap(),
+        _ => return Ok(None),
+    };
+
+    let group = match input.peek() {
+        Some(TokenTree::Group(ref group)) if group.delimiter() == Delimiter::Bracket => {
+            let res = group.clone();
+            input.next();
+            res
+        }
+        other => {
+            let span = other.map_or(Span::call_site(), |tt| tt.span());
+            return Err(Error::new(span, "expected `[`".to_string()));
+        }
+    };
+
+    let path = match group.stream().into_iter().next() {
+        Some(TokenTree::Ident(ident)) => Some(ident),
+        _ => None,
+    };
+
+    Ok(Some(Attribute {
+        shebang,
+        group: TokenTree::Group(group),
+        path,
+    }))
+}
+
+fn parse_signature(input: &mut Peekable<impl Iterator<Item = TokenTree>>) -> Vec<TokenTree> {
+    let mut sig = Vec::new();
+    loop {
+        match input.peek() {
+            Some(TokenTree::Group(ref group)) if group.delimiter() == Delimiter::Brace => {
+                return sig;
+            }
+            None => return sig,
+            _ => sig.push(input.next().unwrap()),
+        }
+    }
+}
+
+pub(crate) struct Attribute {
+    pub(crate) shebang: TokenTree,
+    pub(crate) group: TokenTree,
+    pub(crate) path: Option<Ident>,
+}
+
+impl Attribute {
+    pub(crate) fn path_is_ident(&self, ident: &str) -> bool {
+        self.path.as_ref().map_or(false, |p| *p == ident)
+    }
+}
+
+impl ToTokens for Attribute {
+    fn to_tokens(&self, ts: &mut TokenStream) {
+        self.shebang.to_tokens(ts);
+        self.group.to_tokens(ts);
+    }
+}
-- 
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