[clang] [clang-format] Fix a regression in annotating TrailingReturnArrow (PR #86624)

[Owen Pan via cfe-commits]

https://github.com/owenca created https://github.com/llvm/llvm-project/pull/86624

Fixes #86559.

>From 5ba6a0adcf9de7035dd195f0b83ada39019b7e12 Mon Sep 17 00:00:00 2001
From: Owen Pan <owenpiano at gmail.com>
Date: Mon, 25 Mar 2024 21:13:04 -0700
Subject: [PATCH] [clang-format] Fix a regression in annotating
 TrailingReturnArrow

Fixes #86559.
---
 clang/lib/Format/TokenAnnotator.cpp           | 2 ++
 clang/unittests/Format/TokenAnnotatorTest.cpp | 4 ++++
 2 files changed, 6 insertions(+)

diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
index 4c83a7a3a323be..dd167b07f83453 100644
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -3888,6 +3888,8 @@ void TokenAnnotator::calculateFormattingInformation(AnnotatedLine &Line) const {
       }
     } else if (ClosingParen) {
       for (auto *Tok = ClosingParen->Next; Tok; Tok = Tok->Next) {
+        if (Tok->is(TT_CtorInitializerColon))
+          break;
         if (Tok->is(tok::arrow)) {
           Tok->setType(TT_TrailingReturnArrow);
           break;
diff --git a/clang/unittests/Format/TokenAnnotatorTest.cpp b/clang/unittests/Format/TokenAnnotatorTest.cpp
index 2539d3d76ef019..9425647d99980b 100644
--- a/clang/unittests/Format/TokenAnnotatorTest.cpp
+++ b/clang/unittests/Format/TokenAnnotatorTest.cpp
@@ -1916,6 +1916,10 @@ TEST_F(TokenAnnotatorTest, UnderstandsTrailingReturnArrow) {
   ASSERT_EQ(Tokens.size(), 12u) << Tokens;
   EXPECT_TOKEN(Tokens[7], tok::arrow, TT_Unknown);
 
+  Tokens = annotate("__attribute__((cold)) C() : Base(obj->func()) {}");
+  ASSERT_EQ(Tokens.size(), 21u) << Tokens;
+  EXPECT_TOKEN(Tokens[13], tok::arrow, TT_Unknown);
+
   // Mixed
   Tokens = annotate("auto f() -> int { auto a = b()->c; }");
   ASSERT_EQ(Tokens.size(), 18u) << Tokens;