[llvm-branch-commits] [clang] release/21.x: [clang-format] Allow breaking before bit-field colons (#153529) (PR #154029)

[Tobias Hieta via llvm-branch-commits]

https://github.com/tru updated https://github.com/llvm/llvm-project/pull/154029

>From 228a893b03a979f11f4a9fb0568b0a92b5788780 Mon Sep 17 00:00:00 2001
From: owenca <owenpiano at gmail.com>
Date: Sun, 17 Aug 2025 12:54:23 -0700
Subject: [PATCH] [clang-format] Allow breaking before bit-field colons
 (#153529)

Fixes #153448

(cherry picked from commit 5e57a10f502c8fc524bd119a53ddbf643686c7a0)
---
 clang/lib/Format/TokenAnnotator.cpp   | 3 ++-
 clang/unittests/Format/FormatTest.cpp | 4 ++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
index d28d2fd375fb3..cab4c15e005eb 100644
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -6271,7 +6271,8 @@ bool TokenAnnotator::canBreakBefore(const AnnotatedLine &Line,
   }
 
   if (Right.is(tok::colon) &&
-      !Right.isOneOf(TT_CtorInitializerColon, TT_InlineASMColon)) {
+      !Right.isOneOf(TT_CtorInitializerColon, TT_InlineASMColon,
+                     TT_BitFieldColon)) {
     return false;
   }
   if (Left.is(tok::colon) && Left.isOneOf(TT_DictLiteral, TT_ObjCMethodExpr)) {
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index e161f61e8864e..126e1c92df334 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -4050,6 +4050,10 @@ TEST_F(FormatTest, FormatsBitfields) {
                "  uchar : 8;\n"
                "  uchar other;\n"
                "};");
+  verifyFormat("struct foo {\n"
+               "  uint8_t i_am_a_bit_field_this_long\n"
+               "      : struct_with_constexpr::i_am_a_constexpr_lengthhhhh;\n"
+               "};");
   FormatStyle Style = getLLVMStyle();
   Style.BitFieldColonSpacing = FormatStyle::BFCS_None;
   verifyFormat("struct Bitfields {\n"