[clang] [clang-format] Fix a bug in annotating CastRParen (PR #102261)

[Owen Pan via cfe-commits]

https://github.com/owenca created https://github.com/llvm/llvm-project/pull/102261

Fixes #102102.

>From b72a629d16d5bc3ce800a562fd41ba2dfd1fe1eb Mon Sep 17 00:00:00 2001
From: Owen Pan <owenpiano at gmail.com>
Date: Tue, 6 Aug 2024 18:10:20 -0700
Subject: [PATCH] [clang-format] Fix a bug in annotating CastRParen

Fixes #102102.
---
 clang/lib/Format/TokenAnnotator.cpp           | 11 ++++++++++-
 clang/unittests/Format/TokenAnnotatorTest.cpp |  7 +++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
index 4ed3e9d0e8e85..e1c9f37c6e8dc 100644
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -2874,9 +2874,18 @@ class AnnotatingParser {
       return false;
 
     // Search for unexpected tokens.
-    for (auto *Prev = BeforeRParen; Prev != LParen; Prev = Prev->Previous)
+    for (auto *Prev = BeforeRParen; Prev != LParen; Prev = Prev->Previous) {
+      if (Prev->is(tok::r_paren)) {
+        Prev = Prev->MatchingParen;
+        if (!Prev)
+          return false;
+        if (Prev->is(TT_FunctionTypeLParen))
+          break;
+        continue;
+      }
       if (!Prev->isOneOf(tok::kw_const, tok::identifier, tok::coloncolon))
         return false;
+    }
 
     return true;
   }
diff --git a/clang/unittests/Format/TokenAnnotatorTest.cpp b/clang/unittests/Format/TokenAnnotatorTest.cpp
index 6b71d0d18cf7a..cbbe550a79ebc 100644
--- a/clang/unittests/Format/TokenAnnotatorTest.cpp
+++ b/clang/unittests/Format/TokenAnnotatorTest.cpp
@@ -740,6 +740,13 @@ TEST_F(TokenAnnotatorTest, UnderstandsCasts) {
   EXPECT_TOKEN(Tokens[10], tok::r_paren, TT_Unknown);
   EXPECT_TOKEN(Tokens[11], tok::amp, TT_BinaryOperator);
 
+  Tokens = annotate("func((void (*)())&a);");
+  ASSERT_EQ(Tokens.size(), 15u) << Tokens;
+  EXPECT_TOKEN(Tokens[4], tok::l_paren, TT_FunctionTypeLParen);
+  EXPECT_TOKEN(Tokens[5], tok::star, TT_PointerOrReference);
+  EXPECT_TOKEN(Tokens[9], tok::r_paren, TT_CastRParen);
+  EXPECT_TOKEN(Tokens[10], tok::amp, TT_UnaryOperator);
+
   auto Style = getLLVMStyle();
   Style.TypeNames.push_back("Foo");
   Tokens = annotate("#define FOO(bar) foo((Foo)&bar)", Style);