[clang] [clang-format] Hanlde qualified type names (PR #125327)

[Owen Pan via cfe-commits]

https://github.com/owenca created https://github.com/llvm/llvm-project/pull/125327

Fixes #125178.

>From af3d964d74634f0dd9f7216572c1d852b7a549dc Mon Sep 17 00:00:00 2001
From: Owen Pan <owenpiano at gmail.com>
Date: Fri, 31 Jan 2025 18:32:33 -0800
Subject: [PATCH] [clang-format] Hanlde qualified type names

Fixes #125178.
---
 clang/lib/Format/QualifierAlignmentFixer.cpp  |  8 +++++++-
 clang/unittests/Format/QualifierFixerTest.cpp | 12 ++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/clang/lib/Format/QualifierAlignmentFixer.cpp b/clang/lib/Format/QualifierAlignmentFixer.cpp
index 21fb5074b4928f..f777ac2a89f755 100644
--- a/clang/lib/Format/QualifierAlignmentFixer.cpp
+++ b/clang/lib/Format/QualifierAlignmentFixer.cpp
@@ -132,8 +132,10 @@ static void rotateTokens(const SourceManager &SourceMgr,
   // Then move through the other tokens.
   auto *Tok = Begin;
   while (Tok != End) {
-    if (!NewText.empty() && !endsWithSpace(NewText))
+    if (!NewText.empty() && !endsWithSpace(NewText) &&
+        Tok->isNot(tok::coloncolon)) {
       NewText += " ";
+    }
 
     NewText += Tok->TokenText;
     Tok = Tok->Next;
@@ -412,6 +414,10 @@ const FormatToken *LeftRightQualifierAlignmentFixer::analyzeLeft(
   // The case `const long long volatile int` -> `const volatile long long int`
   // The case `long volatile long int const` -> `const volatile long long int`
   if (TypeToken->isTypeName(LangOpts)) {
+    if (const auto *Prev = TypeToken->getPreviousNonComment();
+        Prev && Prev->endsSequence(tok::coloncolon, tok::identifier)) {
+      TypeToken = Prev->getPreviousNonComment();
+    }
     const FormatToken *LastSimpleTypeSpecifier = TypeToken;
     while (isConfiguredQualifierOrType(
         LastSimpleTypeSpecifier->getPreviousNonComment(),
diff --git a/clang/unittests/Format/QualifierFixerTest.cpp b/clang/unittests/Format/QualifierFixerTest.cpp
index 129828b0d187a9..530587bbf2ca74 100644
--- a/clang/unittests/Format/QualifierFixerTest.cpp
+++ b/clang/unittests/Format/QualifierFixerTest.cpp
@@ -1291,6 +1291,18 @@ TEST_F(QualifierFixerTest, WithCpp11Attribute) {
                "[[maybe_unused]] constexpr static int A", Style);
 }
 
+TEST_F(QualifierFixerTest, WithQualifiedTypeName) {
+  auto Style = getLLVMStyle();
+  Style.QualifierAlignment = FormatStyle::QAS_Custom;
+  Style.QualifierOrder = {"constexpr", "type", "const"};
+
+  verifyFormat("constexpr std::int64_t x{123};",
+               "std::int64_t constexpr x{123};", Style);
+
+  Style.TypeNames.push_back("bar");
+  verifyFormat("constexpr foo::bar x{12};", "foo::bar constexpr x{12};", Style);
+}
+
 TEST_F(QualifierFixerTest, DisableRegions) {
   FormatStyle Style = getLLVMStyle();
   Style.QualifierAlignment = FormatStyle::QAS_Custom;