[clang] [clang-format] Handle bit-field colon of non-numeric-constant size (PR #142110)

[Owen Pan via cfe-commits]

https://github.com/owenca created https://github.com/llvm/llvm-project/pull/142110

Fix #142050

>From 9cf70104e03372be9122d44a87694cd04b9b34c9 Mon Sep 17 00:00:00 2001
From: Owen Pan <owenpiano at gmail.com>
Date: Fri, 30 May 2025 01:52:31 -0700
Subject: [PATCH] [clang-format] Handle bit-field colon of non-numeric-constant
 size

Fix #142050
---
 clang/lib/Format/TokenAnnotator.cpp           | 4 +++-
 clang/unittests/Format/TokenAnnotatorTest.cpp | 8 ++++++++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
index 51ececc0c0e81..f8272811bbe6c 100644
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -1411,7 +1411,9 @@ class AnnotatingParser {
         assert(Prev);
         if (Prev->isPointerOrReference())
           Prev->setFinalizedType(TT_PointerOrReference);
-      } else if (CurrentToken && CurrentToken->is(tok::numeric_constant)) {
+      } else if ((CurrentToken && CurrentToken->is(tok::numeric_constant)) ||
+                 (Prev && Prev->is(TT_StartOfName) && !Scopes.empty() &&
+                  Scopes.back() == ST_Class)) {
         Tok->setType(TT_BitFieldColon);
       } else if (Contexts.size() == 1 &&
                  !Line.getFirstNonComment()->isOneOf(tok::kw_enum, tok::kw_case,
diff --git a/clang/unittests/Format/TokenAnnotatorTest.cpp b/clang/unittests/Format/TokenAnnotatorTest.cpp
index f39468424a393..1a5ed4b9040c2 100644
--- a/clang/unittests/Format/TokenAnnotatorTest.cpp
+++ b/clang/unittests/Format/TokenAnnotatorTest.cpp
@@ -4076,6 +4076,14 @@ TEST_F(TokenAnnotatorTest, EnumColonInTypedef) {
   EXPECT_TOKEN(Tokens[2], tok::colon, TT_Unknown); // Not TT_InheritanceColon.
 }
 
+TEST_F(TokenAnnotatorTest, BitFieldColon) {
+  auto Tokens = annotate("class C {\n"
+                         "  int f : SIZE;\n"
+                         "};");
+  ASSERT_EQ(Tokens.size(), 11u) << Tokens;
+  EXPECT_TOKEN(Tokens[5], tok::colon, TT_BitFieldColon);
+}
+
 } // namespace
 } // namespace format
 } // namespace clang