[clang] [clang-format] Add AccessModifierMacros option (PR #187521)

[Leszek Swirski via cfe-commits]

https://github.com/LeszekSwirski updated https://github.com/llvm/llvm-project/pull/187521

>From c4062cc7fa89db83702326c072b2d3ca407496c6 Mon Sep 17 00:00:00 2001
From: Leszek Swirski <leszeks at google.com>
Date: Thu, 19 Mar 2026 16:22:13 +0100
Subject: [PATCH] [clang-format] Add AccessModifierMacros option

Fixes #64763.

This option allows users to specify custom macros that are treated as access modifiers.
---
 clang/include/clang/Format/Format.h   |  8 +++++++-
 clang/lib/Format/Format.cpp           |  1 +
 clang/lib/Format/FormatToken.h        |  4 +++-
 clang/lib/Format/FormatTokenLexer.cpp |  4 ++++
 clang/lib/Format/TokenAnnotator.cpp   |  2 +-
 clang/unittests/Format/FormatTest.cpp | 19 +++++++++++++++++++
 6 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/clang/include/clang/Format/Format.h b/clang/include/clang/Format/Format.h
index c7e57d47f9ed1..d514cc539dd9d 100644
--- a/clang/include/clang/Format/Format.h
+++ b/clang/include/clang/Format/Format.h
@@ -62,6 +62,11 @@ struct FormatStyle {
   /// \version 3.3
   int AccessModifierOffset;
 
+  /// A list of macros that should be interpreted as access modifiers instead of
+  /// as a regular identifier.
+  /// \version 22
+  std::vector<std::string> AccessModifierMacros;
+
   /// If ``true``, horizontally aligns arguments after an open bracket.
   ///
   /// \code
@@ -5638,7 +5643,8 @@ struct FormatStyle {
   WrapNamespaceBodyWithEmptyLinesStyle WrapNamespaceBodyWithEmptyLines;
 
   bool operator==(const FormatStyle &R) const {
-    return AccessModifierOffset == R.AccessModifierOffset &&
+    return AccessModifierMacros == R.AccessModifierMacros &&
+           AccessModifierOffset == R.AccessModifierOffset &&
            AlignAfterOpenBracket == R.AlignAfterOpenBracket &&
            AlignArrayOfStructures == R.AlignArrayOfStructures &&
            AlignConsecutiveAssignments == R.AlignConsecutiveAssignments &&
diff --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp
index f0e9aff2fd21a..96fb0b37990d7 100644
--- a/clang/lib/Format/Format.cpp
+++ b/clang/lib/Format/Format.cpp
@@ -1077,6 +1077,7 @@ template <> struct MappingTraits<FormatStyle> {
       IO.mapOptional("UseCRLF", UseCRLF);
     }
 
+    IO.mapOptional("AccessModifierMacros", Style.AccessModifierMacros);
     IO.mapOptional("AccessModifierOffset", Style.AccessModifierOffset);
     IO.mapOptional("AlignArrayOfStructures", Style.AlignArrayOfStructures);
     IO.mapOptional("AlignConsecutiveAssignments",
diff --git a/clang/lib/Format/FormatToken.h b/clang/lib/Format/FormatToken.h
index 56abd702aaafe..66ea234dda7fc 100644
--- a/clang/lib/Format/FormatToken.h
+++ b/clang/lib/Format/FormatToken.h
@@ -25,6 +25,7 @@ namespace clang {
 namespace format {
 
 #define LIST_TOKEN_TYPES                                                       \
+  TYPE(AccessModifierMacro)                                                    \
   TYPE(AfterPPDirective)                                                       \
   TYPE(ArrayInitializerLSquare)                                                \
   TYPE(ArraySubscriptLSquare)                                                  \
@@ -705,7 +706,8 @@ struct FormatToken {
   }
 
   bool isAccessSpecifierKeyword() const {
-    return isOneOf(tok::kw_public, tok::kw_protected, tok::kw_private);
+    return isOneOf(tok::kw_public, tok::kw_protected, tok::kw_private) ||
+           is(TT_AccessModifierMacro);
   }
 
   bool isAccessSpecifier(bool ColonRequired = true) const {
diff --git a/clang/lib/Format/FormatTokenLexer.cpp b/clang/lib/Format/FormatTokenLexer.cpp
index eb8658396ecde..7a8330c82528a 100644
--- a/clang/lib/Format/FormatTokenLexer.cpp
+++ b/clang/lib/Format/FormatTokenLexer.cpp
@@ -55,6 +55,10 @@ FormatTokenLexer::FormatTokenLexer(
     auto Identifier = &IdentTable.get(StatementMacro);
     Macros.insert({Identifier, TT_StatementMacro});
   }
+  for (const std::string &AccessModifierMacro : Style.AccessModifierMacros) {
+    auto Identifier = &IdentTable.get(AccessModifierMacro);
+    Macros.insert({Identifier, TT_AccessModifierMacro});
+  }
   for (const std::string &TypenameMacro : Style.TypenameMacros) {
     auto Identifier = &IdentTable.get(TypenameMacro);
     Macros.insert({Identifier, TT_TypenameMacro});
diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
index 3208d8e28dd86..948c7c5abba37 100644
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -2115,7 +2115,7 @@ class AnnotatingParser {
             TT_RequiresClauseInARequiresExpression, TT_RequiresExpression,
             TT_RequiresExpressionLParen, TT_RequiresExpressionLBrace,
             TT_CompoundRequirementLBrace, TT_BracedListLBrace,
-            TT_FunctionLikeMacro)) {
+            TT_FunctionLikeMacro, TT_AccessModifierMacro)) {
       CurrentToken->setType(TT_Unknown);
     }
     CurrentToken->Role.reset();
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 3ee7ce38578aa..73f3e4801262a 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -13320,6 +13320,25 @@ TEST_F(FormatTest, FormatsAccessModifiers) {
                NoEmptyLines);
 }
 
+TEST_F(FormatTest, AccessModifierMacros) {
+  FormatStyle Style = getLLVMStyle();
+  Style.AccessModifierMacros.push_back("COMPREHENSIVE_O_PRIVATE");
+  Style.AccessModifierMacros.push_back("COMPREHENSIVE_O_PUBLIC");
+
+  verifyFormat("struct foo {\n"
+               "COMPREHENSIVE_O_PRIVATE:\n"
+               "  void f() {}\n"
+               "\n"
+               "COMPREHENSIVE_O_PRIVATE:\n"
+               "  int i;\n"
+               "\n"
+               "COMPREHENSIVE_O_PUBLIC:\n"
+               "  int j;\n"
+               "};",
+               Style);
+}
+
+
 TEST_F(FormatTest, FormatsAfterAccessModifiers) {
 
   FormatStyle Style = getLLVMStyle();