From d9f2fdfaed8d18ede6d113426279c86d84d92445 Mon Sep 17 00:00:00 2001
From: Nicholas Nethercote <n.nethercote@gmail.com>
Date: Mon, 31 Jul 2023 15:47:19 +1000
Subject: [PATCH] `parse_all_token_trees` cannot fail.

---
 compiler/rustc_parse/src/parser/mod.rs        | 4 ++--
 src/librustdoc/clean/render_macro_matchers.rs | 8 +-------
 2 files changed, 3 insertions(+), 9 deletions(-)

diff --git a/compiler/rustc_parse/src/parser/mod.rs b/compiler/rustc_parse/src/parser/mod.rs
index 57778d67098..b452eb6a401 100644
--- a/compiler/rustc_parse/src/parser/mod.rs
+++ b/compiler/rustc_parse/src/parser/mod.rs
@@ -1288,12 +1288,12 @@ pub(crate) fn parse_token_tree(&mut self) -> TokenTree {
     }
 
     /// Parses a stream of tokens into a list of `TokenTree`s, up to EOF.
-    pub fn parse_all_token_trees(&mut self) -> PResult<'a, Vec<TokenTree>> {
+    pub fn parse_all_token_trees(&mut self) -> Vec<TokenTree> {
         let mut tts = Vec::new();
         while self.token != token::Eof {
             tts.push(self.parse_token_tree());
         }
-        Ok(tts)
+        tts
     }
 
     pub fn parse_tokens(&mut self) -> TokenStream {
diff --git a/src/librustdoc/clean/render_macro_matchers.rs b/src/librustdoc/clean/render_macro_matchers.rs
index ef38ca3c16c..b6120e814df 100644
--- a/src/librustdoc/clean/render_macro_matchers.rs
+++ b/src/librustdoc/clean/render_macro_matchers.rs
@@ -76,13 +76,7 @@ fn snippet_equal_to_token(tcx: TyCtxt<'_>, matcher: &TokenTree) -> Option<String
         };
 
     // Reparse a single token tree.
-    let mut reparsed_trees = match parser.parse_all_token_trees() {
-        Ok(reparsed_trees) => reparsed_trees,
-        Err(diagnostic) => {
-            diagnostic.cancel();
-            return None;
-        }
-    };
+    let mut reparsed_trees = parser.parse_all_token_trees();
     if reparsed_trees.len() != 1 {
         return None;
     }