[llvm-branch-commits] [clang] release/21.x: [clang-format] Don't swap `(const override)` with QAS_Right (#167191) (PR #170966)

[via llvm-branch-commits]

https://github.com/llvmbot created https://github.com/llvm/llvm-project/pull/170966

Backport dfe9838f9c790aa632bed0a1b67976c2a7e95f76

Requested by: @owenca

>From 17d714fcb43dd9361ba32895d2a185e008ac6961 Mon Sep 17 00:00:00 2001
From: owenca <owenpiano at gmail.com>
Date: Wed, 12 Nov 2025 20:55:34 -0800
Subject: [PATCH] [clang-format] Don't swap `(const override)` with QAS_Right
 (#167191)

Fixes #154846

(cherry picked from commit dfe9838f9c790aa632bed0a1b67976c2a7e95f76)
---
 clang/lib/Format/QualifierAlignmentFixer.cpp  | 17 +++++++++++++----
 clang/unittests/Format/QualifierFixerTest.cpp |  2 ++
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/clang/lib/Format/QualifierAlignmentFixer.cpp b/clang/lib/Format/QualifierAlignmentFixer.cpp
index 441a37a4902b7..cc59dbd13621d 100644
--- a/clang/lib/Format/QualifierAlignmentFixer.cpp
+++ b/clang/lib/Format/QualifierAlignmentFixer.cpp
@@ -182,8 +182,11 @@ const FormatToken *LeftRightQualifierAlignmentFixer::analyzeRight(
   // We only need to think about streams that begin with a qualifier.
   if (Tok->isNot(QualifierType))
     return Tok;
+
+  const auto *Next = Tok->getNextNonComment();
+
   // Don't concern yourself if nothing follows the qualifier.
-  if (!Tok->Next)
+  if (!Next)
     return Tok;
 
   // Skip qualifiers to the left to find what preceeds the qualifiers.
@@ -247,9 +250,15 @@ const FormatToken *LeftRightQualifierAlignmentFixer::analyzeRight(
   }();
 
   // Find the last qualifier to the right.
-  const FormatToken *LastQual = Tok;
-  while (isQualifier(LastQual->getNextNonComment()))
-    LastQual = LastQual->getNextNonComment();
+  const auto *LastQual = Tok;
+  for (; isQualifier(Next); Next = Next->getNextNonComment())
+    LastQual = Next;
+
+  if (!LastQual || !Next ||
+      (LastQual->isOneOf(tok::kw_const, tok::kw_volatile) &&
+       Next->isOneOf(Keywords.kw_override, Keywords.kw_final))) {
+    return Tok;
+  }
 
   // If this qualifier is to the right of a type or pointer do a partial sort
   // and return.
diff --git a/clang/unittests/Format/QualifierFixerTest.cpp b/clang/unittests/Format/QualifierFixerTest.cpp
index f42f2e307f713..55bdda32453ba 100644
--- a/clang/unittests/Format/QualifierFixerTest.cpp
+++ b/clang/unittests/Format/QualifierFixerTest.cpp
@@ -215,6 +215,8 @@ TEST_F(QualifierFixerTest, RightQualifier) {
                Style);
   verifyFormat("void foo() const override;", Style);
   verifyFormat("void foo() const override LLVM_READONLY;", Style);
+  verifyFormat("MOCK_METHOD(ReturnType, myMethod, (int), (const override));",
+               Style);
   verifyFormat("void foo() const final;", Style);
   verifyFormat("void foo() const final LLVM_READONLY;", Style);
   verifyFormat("void foo() const LLVM_READONLY;", Style);