[clang] [clang-format] fix aligning inheritance lists with UT_AlignWithSpaces (PR #189218)

[Eugene Shalygin via cfe-commits]

https://github.com/zeule created https://github.com/llvm/llvm-project/pull/189218

None

>From d9a3df4c368001e1de7936c43da1be39a9a32385 Mon Sep 17 00:00:00 2001
From: Eugene Shalygin <e.shalygin at abberior-instruments.com>
Date: Fri, 27 Mar 2026 17:02:04 +0100
Subject: [PATCH] [clang-format] fix aligning inheritance lists with
 UT_AlignWithSpaces

---
 clang/lib/Format/ContinuationIndenter.cpp | 12 ++++++++++++
 clang/unittests/Format/FormatTest.cpp     | 12 ++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/clang/lib/Format/ContinuationIndenter.cpp b/clang/lib/Format/ContinuationIndenter.cpp
index a388b74920e0b..8201706275776 100644
--- a/clang/lib/Format/ContinuationIndenter.cpp
+++ b/clang/lib/Format/ContinuationIndenter.cpp
@@ -1237,6 +1237,18 @@ unsigned ContinuationIndenter::addTokenOnNewLine(LineState &State,
           Style.ContinuationIndentWidth;
     }
   }
+  if (Style.BreakInheritanceList == FormatStyle::BILS_AfterComma) {
+    if (Previous.isOneOf(TT_InheritanceComma, tok::comma) &&
+        Current.isOneOf(tok::kw_private, tok::kw_protected, tok::kw_public)) {
+      CurrentState.IsAligned = true;
+    }
+  }
+  if (Style.BreakInheritanceList == FormatStyle::BILS_BeforeColon) {
+    if (Previous.isOneOf(TT_InheritanceComma, tok::comma) &&
+        Current.isOneOf(tok::kw_private, tok::kw_protected, tok::kw_public)) {
+      CurrentState.IsAligned = true;
+    }
+  }
 
   if ((PreviousNonComment &&
        PreviousNonComment->isOneOf(tok::comma, tok::semi) &&
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 3d55a814e6027..bf087387b1d2b 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -8433,6 +8433,18 @@ TEST_F(FormatTest, BreakConstructorInitializersAfterColon) {
       "  : public aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa,\n"
       "    public bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb {};",
       Style);
+  FormatStyle Tab = getLLVMStyleWithColumns(42);
+  Tab.IndentWidth = 4;
+  Tab.TabWidth = 4;
+  Tab.UseTab = FormatStyle::UT_AlignWithSpaces;
+  verifyFormat("class Foo : public aaaaaaaaa,\n"
+               "            public bbbbbbbbb\n",
+               Tab);
+  verifyFormat("struct S {\n"
+               "\tclass Foo : public aaaaaaaaa,\n"
+               "\t            public bbbbbbbbb {};\n"
+               "};",
+               Tab);
 }
 
 TEST_F(FormatTest, BreakConstructorInitializersAfterComma) {