[clang] [clang-format] Fix a bug in annotating ClassHeadName (PR #125326)

[Owen Pan via cfe-commits]

https://github.com/owenca created https://github.com/llvm/llvm-project/pull/125326

None

>From d2a9862cb4f88ebb92f0d5266ffd80aec51b8f04 Mon Sep 17 00:00:00 2001
From: Owen Pan <owenpiano at gmail.com>
Date: Fri, 31 Jan 2025 18:19:37 -0800
Subject: [PATCH] [clang-format] Fix a bug in annotating ClassHeadName

---
 clang/lib/Format/UnwrappedLineParser.cpp      | 2 +-
 clang/unittests/Format/TokenAnnotatorTest.cpp | 7 +++++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/clang/lib/Format/UnwrappedLineParser.cpp b/clang/lib/Format/UnwrappedLineParser.cpp
index 1411197e325549..4e040183f2f0a3 100644
--- a/clang/lib/Format/UnwrappedLineParser.cpp
+++ b/clang/lib/Format/UnwrappedLineParser.cpp
@@ -4106,7 +4106,7 @@ void UnwrappedLineParser::parseRecord(bool ParseAsExpr) {
       if (AngleNestingLevel == 0) {
         if (FormatTok->is(tok::colon)) {
           IsDerived = true;
-        } else if (FormatTok->is(tok::identifier) &&
+        } else if (!IsDerived && FormatTok->is(tok::identifier) &&
                    FormatTok->Previous->is(tok::coloncolon)) {
           ClassName = FormatTok;
         } else if (FormatTok->is(tok::l_paren) &&
diff --git a/clang/unittests/Format/TokenAnnotatorTest.cpp b/clang/unittests/Format/TokenAnnotatorTest.cpp
index 9995f090d441f7..1b09c457034562 100644
--- a/clang/unittests/Format/TokenAnnotatorTest.cpp
+++ b/clang/unittests/Format/TokenAnnotatorTest.cpp
@@ -3406,6 +3406,13 @@ TEST_F(TokenAnnotatorTest, BraceKind) {
   EXPECT_BRACE_KIND(Tokens[7], BK_Block);
   EXPECT_BRACE_KIND(Tokens[8], BK_Block);
 
+  Tokens = annotate("struct Foo<int> : Base::Bar {};");
+  ASSERT_EQ(Tokens.size(), 13u) << Tokens;
+  EXPECT_TOKEN(Tokens[1], tok::identifier, TT_ClassHeadName);
+  EXPECT_TOKEN(Tokens[8], tok::identifier, TT_Unknown); // Not TT_ClassHeadName.
+  EXPECT_BRACE_KIND(Tokens[9], BK_Block);
+  EXPECT_BRACE_KIND(Tokens[10], BK_Block);
+
   Tokens = annotate("struct Foo final {};");
   ASSERT_EQ(Tokens.size(), 7u) << Tokens;
   EXPECT_TOKEN(Tokens[1], tok::identifier, TT_ClassHeadName);