[clang] [clang-format] Fix a bug in annotating braces (PR #134039)

[Owen Pan via cfe-commits]

https://github.com/owenca created https://github.com/llvm/llvm-project/pull/134039

Fix #133873

>From 50f03ef8b041cacba171ce0cfb156e4f677a9353 Mon Sep 17 00:00:00 2001
From: Owen Pan <owenpiano at gmail.com>
Date: Tue, 1 Apr 2025 23:54:33 -0700
Subject: [PATCH] [clang-format] Fix a bug in annotating braces

Fix #133873
---
 clang/lib/Format/UnwrappedLineParser.cpp      | 6 +++++-
 clang/unittests/Format/TokenAnnotatorTest.cpp | 5 +++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/clang/lib/Format/UnwrappedLineParser.cpp b/clang/lib/Format/UnwrappedLineParser.cpp
index f7712bea01c2c..213b706807b2a 100644
--- a/clang/lib/Format/UnwrappedLineParser.cpp
+++ b/clang/lib/Format/UnwrappedLineParser.cpp
@@ -1887,8 +1887,11 @@ void UnwrappedLineParser::parseStructuralElement(
       if (FormatTok->isBinaryOperator())
         nextToken();
       break;
-    case tok::caret:
+    case tok::caret: {
+      const auto *Prev = FormatTok->getPreviousNonComment();
       nextToken();
+      if (Prev && Prev->is(tok::identifier))
+        break;
       // Block return type.
       if (FormatTok->Tok.isAnyIdentifier() || FormatTok->isTypeName(LangOpts)) {
         nextToken();
@@ -1903,6 +1906,7 @@ void UnwrappedLineParser::parseStructuralElement(
       if (FormatTok->is(tok::l_brace))
         parseChildBlock();
       break;
+    }
     case tok::l_brace:
       if (InRequiresExpression)
         FormatTok->setFinalizedType(TT_BracedListLBrace);
diff --git a/clang/unittests/Format/TokenAnnotatorTest.cpp b/clang/unittests/Format/TokenAnnotatorTest.cpp
index af9fd574b068c..7e0af1c7b4c36 100644
--- a/clang/unittests/Format/TokenAnnotatorTest.cpp
+++ b/clang/unittests/Format/TokenAnnotatorTest.cpp
@@ -3622,6 +3622,11 @@ TEST_F(TokenAnnotatorTest, BraceKind) {
   ASSERT_EQ(Tokens.size(), 11u) << Tokens;
   EXPECT_BRACE_KIND(Tokens[7], BK_BracedInit);
   EXPECT_BRACE_KIND(Tokens[9], BK_BracedInit);
+
+  Tokens = annotate("return lhs ^ Byte{rhs};");
+  ASSERT_EQ(Tokens.size(), 9u) << Tokens;
+  EXPECT_BRACE_KIND(Tokens[4], BK_BracedInit);
+  EXPECT_BRACE_KIND(Tokens[6], BK_BracedInit);
 }
 
 TEST_F(TokenAnnotatorTest, UnderstandsElaboratedTypeSpecifier) {