[clang] [clang-format] Merge inline short functions for BS_Whitesmiths (PR #134473)

[Owen Pan via cfe-commits]

https://github.com/owenca created https://github.com/llvm/llvm-project/pull/134473

Fix 126747

>From 12acc02f8ffd2317ed1197d7397cb1abc1a4fd07 Mon Sep 17 00:00:00 2001
From: Owen Pan <owenpiano at gmail.com>
Date: Fri, 4 Apr 2025 19:31:12 -0700
Subject: [PATCH] [clang-format] Merge inline short functions for
 BS_Whitesmiths

Fix 126747
---
 clang/lib/Format/UnwrappedLineFormatter.cpp | 9 +++++++--
 clang/unittests/Format/FormatTest.cpp       | 7 +++++++
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/clang/lib/Format/UnwrappedLineFormatter.cpp b/clang/lib/Format/UnwrappedLineFormatter.cpp
index 000a5105ca407..62759d7945f7b 100644
--- a/clang/lib/Format/UnwrappedLineFormatter.cpp
+++ b/clang/lib/Format/UnwrappedLineFormatter.cpp
@@ -316,8 +316,13 @@ class LineJoiner {
           const AnnotatedLine *Line = nullptr;
           for (auto J = I - 1; J >= AnnotatedLines.begin(); --J) {
             assert(*J);
-            if (!(*J)->InPPDirective && !(*J)->isComment() &&
-                (*J)->Level < TheLine->Level) {
+            if ((*J)->InPPDirective || (*J)->isComment() ||
+                (*J)->Level > TheLine->Level) {
+              continue;
+            }
+            if ((*J)->Level < TheLine->Level ||
+                (Style.BreakBeforeBraces == FormatStyle::BS_Whitesmiths &&
+                 (*J)->First->is(tok::l_brace))) {
               Line = *J;
               break;
             }
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 4dfa135120605..69c9ee1d1dcb2 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -15142,6 +15142,13 @@ TEST_F(FormatTest, PullInlineOnlyFunctionDefinitionsIntoSingleLine) {
                "}",
                MergeInlineOnly);
 
+  MergeInlineOnly.BreakBeforeBraces = FormatStyle::BS_Whitesmiths;
+  verifyFormat("class Foo\n"
+               "  {\n"
+               "  void f() { foo(); }\n"
+               "  };",
+               MergeInlineOnly);
+
   // Also verify behavior when BraceWrapping.AfterFunction = true
   MergeInlineOnly.BreakBeforeBraces = FormatStyle::BS_Custom;
   MergeInlineOnly.BraceWrapping.AfterFunction = true;