[clang] [clang-format] Correctly annotate ObjC `* __autoreleasing *` (PR #138799)

[Owen Pan via cfe-commits]

https://github.com/owenca created https://github.com/llvm/llvm-project/pull/138799

Fix #138484

>From ec9f832cedf7abd4d90d8cf3dca45ee128b922a9 Mon Sep 17 00:00:00 2001
From: Owen Pan <owenpiano at gmail.com>
Date: Tue, 6 May 2025 20:13:26 -0700
Subject: [PATCH] [clang-format] Correctly annotate ObjC `* __autoreleasing *`

Fix #138484
---
 clang/lib/Format/FormatToken.h                | 8 ++++++++
 clang/lib/Format/TokenAnnotator.cpp           | 3 ++-
 clang/unittests/Format/TokenAnnotatorTest.cpp | 6 ++++++
 3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/clang/lib/Format/FormatToken.h b/clang/lib/Format/FormatToken.h
index 946cd7b81587f..b570171d032ac 100644
--- a/clang/lib/Format/FormatToken.h
+++ b/clang/lib/Format/FormatToken.h
@@ -711,6 +711,14 @@ struct FormatToken {
                          tok::objc_package, tok::objc_private);
   }
 
+  bool isObjCLifetimeQualifier(const FormatStyle &Style) const {
+    if (Style.Language != FormatStyle::LK_ObjC || !TokenText.starts_with("__"))
+      return false;
+    const auto Qualifier = TokenText.substr(2);
+    return Qualifier == "autoreleasing" || Qualifier == "strong" ||
+           Qualifier == "weak" || Qualifier == "unsafe_unretained";
+  }
+
   /// Returns whether \p Tok is ([{ or an opening < of a template or in
   /// protos.
   bool opensScope() const {
diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
index ac6551b2bd1ad..f0f9207564ab1 100644
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -3100,7 +3100,8 @@ class AnnotatingParser {
       if (NextNextToken) {
         if (NextNextToken->is(tok::arrow))
           return TT_BinaryOperator;
-        if (NextNextToken->isPointerOrReference()) {
+        if (NextNextToken->isPointerOrReference() &&
+            !NextToken->isObjCLifetimeQualifier(Style)) {
           NextNextToken->setFinalizedType(TT_BinaryOperator);
           return TT_BinaryOperator;
         }
diff --git a/clang/unittests/Format/TokenAnnotatorTest.cpp b/clang/unittests/Format/TokenAnnotatorTest.cpp
index bcb2b6f33d1ad..7982ccb167b53 100644
--- a/clang/unittests/Format/TokenAnnotatorTest.cpp
+++ b/clang/unittests/Format/TokenAnnotatorTest.cpp
@@ -411,6 +411,12 @@ TEST_F(TokenAnnotatorTest, UnderstandsUsesOfStarAndAmp) {
   ASSERT_EQ(Tokens.size(), 27u) << Tokens;
   EXPECT_TOKEN(Tokens[16], tok::star, TT_BinaryOperator);
   EXPECT_TOKEN(Tokens[22], tok::star, TT_BinaryOperator);
+
+  Tokens = annotate("NSError *__autoreleasing *foo;",
+                    getLLVMStyle(FormatStyle::LK_ObjC));
+  ASSERT_EQ(Tokens.size(), 7u) << Tokens;
+  EXPECT_TOKEN(Tokens[1], tok::star, TT_PointerOrReference);
+  EXPECT_TOKEN(Tokens[3], tok::star, TT_PointerOrReference);
 }
 
 TEST_F(TokenAnnotatorTest, UnderstandsUsesOfPlusAndMinus) {