[llvm-branch-commits] [clang] release/21.x: [clang-format] Fix a bug in breaking before FunctionDeclarationName (#153924) (PR #154030)

[Tobias Hieta via llvm-branch-commits]

https://github.com/tru updated https://github.com/llvm/llvm-project/pull/154030

>From fcb91597e2e9e041afc5bb4e710e80e465b7d998 Mon Sep 17 00:00:00 2001
From: owenca <owenpiano at gmail.com>
Date: Sun, 17 Aug 2025 12:54:48 -0700
Subject: [PATCH] [clang-format] Fix a bug in breaking before
 FunctionDeclarationName (#153924)

Fixes #153891

(cherry picked from commit a21d17f1d7173cdbc25f141595a0be9056760f77)
---
 clang/lib/Format/ContinuationIndenter.cpp | 11 +++++++++--
 clang/unittests/Format/FormatTest.cpp     | 10 +++++++++-
 2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/clang/lib/Format/ContinuationIndenter.cpp b/clang/lib/Format/ContinuationIndenter.cpp
index 4010f7fbd25be..099994695dec5 100644
--- a/clang/lib/Format/ContinuationIndenter.cpp
+++ b/clang/lib/Format/ContinuationIndenter.cpp
@@ -628,9 +628,16 @@ bool ContinuationIndenter::mustBreak(const LineState &State) {
       // name.
       !Style.isJavaScript() && Previous.isNot(tok::kw_template) &&
       CurrentState.BreakBeforeParameter) {
-    for (const auto *Tok = &Previous; Tok; Tok = Tok->Previous)
-      if (Tok->FirstAfterPPLine || Tok->is(TT_LineComment))
+    for (const auto *Tok = &Previous; Tok; Tok = Tok->Previous) {
+      if (Tok->is(TT_LineComment))
         return false;
+      if (Tok->is(TT_TemplateCloser)) {
+        Tok = Tok->MatchingParen;
+        assert(Tok);
+      }
+      if (Tok->FirstAfterPPLine)
+        return false;
+    }
 
     return true;
   }
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 126e1c92df334..95682f2d8cfd4 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -8596,7 +8596,7 @@ TEST_F(FormatTest, BreaksFunctionDeclarations) {
   verifyFormat("extern \"C\" //\n"
                "    void f();");
 
-  FormatStyle Style = getLLVMStyle();
+  auto Style = getLLVMStyle();
   Style.PointerAlignment = FormatStyle::PAS_Left;
   verifyFormat("void aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa(\n"
                "    aaaaaaaaaaaaaaaaaaaaaaaaa* const aaaaaaaaaaaa) {}",
@@ -8604,6 +8604,14 @@ TEST_F(FormatTest, BreaksFunctionDeclarations) {
   verifyFormat("void aaaaaaa(aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa*\n"
                "                 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa) {}",
                Style);
+
+  Style = getLLVMStyleWithColumns(45);
+  Style.PenaltyReturnTypeOnItsOwnLine = 400;
+  verifyFormat("template <bool abool, // a comment\n"
+               "          bool anotherbool>\n"
+               "static inline std::pair<size_t, MyCustomType>\n"
+               "myfunc(const char *buf, const char *&err);",
+               Style);
 }
 
 TEST_F(FormatTest, DontBreakBeforeQualifiedOperator) {