[clang] [clang-format] Add PenaltyBreakScopeResolution option. (PR #78015)

[via cfe-commits]

https://github.com/rmarker created https://github.com/llvm/llvm-project/pull/78015

Resolves #78014

>From 7b072cbf52418e92962bb8eb8a24471e5c01f1ea Mon Sep 17 00:00:00 2001
From: rmarker <rmarker at outlook.com>
Date: Wed, 10 Jan 2024 10:55:51 +1030
Subject: [PATCH] [clang-format] Add PenaltyBreakScopeResolution option.

---
 clang/docs/ClangFormatStyleOptions.rst     |  5 +++++
 clang/docs/ReleaseNotes.rst                |  1 +
 clang/include/clang/Format/Format.h        |  5 +++++
 clang/lib/Format/Format.cpp                |  3 +++
 clang/lib/Format/TokenAnnotator.cpp        |  2 +-
 clang/unittests/Format/ConfigParseTest.cpp |  2 ++
 clang/unittests/Format/FormatTest.cpp      | 13 +++++++++++++
 7 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/clang/docs/ClangFormatStyleOptions.rst b/clang/docs/ClangFormatStyleOptions.rst
index ac9a0b70ed5daa4..8bc13e45bf2f5fa 100644
--- a/clang/docs/ClangFormatStyleOptions.rst
+++ b/clang/docs/ClangFormatStyleOptions.rst
@@ -4432,6 +4432,11 @@ the configuration (without a prefix: ``Auto``).
 **PenaltyBreakOpenParenthesis** (``Unsigned``) :versionbadge:`clang-format 14` :ref:`¶ <PenaltyBreakOpenParenthesis>`
   The penalty for breaking after ``(``.
 
+.. _PenaltyBreakScopeResolution:
+
+**PenaltyBreakScopeResolution** (``Unsigned``) :versionbadge:`clang-format 18` :ref:`¶ <PenaltyBreakScopeResolution>`
+  The penalty for breaking after ``::``.
+
 .. _PenaltyBreakString:
 
 **PenaltyBreakString** (``Unsigned``) :versionbadge:`clang-format 3.7` :ref:`¶ <PenaltyBreakString>`
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 3cbce1be1594376..dc8a6fe506bce65 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -1131,6 +1131,7 @@ clang-format
 - Add ``BreakAdjacentStringLiterals`` option.
 - Add ``ObjCPropertyAttributeOrder`` which can be used to sort ObjC property
   attributes (like ``nonatomic, strong, nullable``).
+- Add ``PenaltyBreakScopeResolution`` option.
 - Add ``.clang-format-ignore`` files.
 - Add ``AlignFunctionPointers`` sub-option for ``AlignConsecutiveDeclarations``.
 
diff --git a/clang/include/clang/Format/Format.h b/clang/include/clang/Format/Format.h
index 5ffd63ee73fc361..6fd7947bd217911 100644
--- a/clang/include/clang/Format/Format.h
+++ b/clang/include/clang/Format/Format.h
@@ -3398,6 +3398,10 @@ struct FormatStyle {
   /// \version 14
   unsigned PenaltyBreakOpenParenthesis;
 
+  /// The penalty for breaking after ``::``.
+  /// \version 18
+  unsigned PenaltyBreakScopeResolution;
+
   /// The penalty for each line break introduced inside a string literal.
   /// \version 3.7
   unsigned PenaltyBreakString;
@@ -4873,6 +4877,7 @@ struct FormatStyle {
            PenaltyBreakComment == R.PenaltyBreakComment &&
            PenaltyBreakFirstLessLess == R.PenaltyBreakFirstLessLess &&
            PenaltyBreakOpenParenthesis == R.PenaltyBreakOpenParenthesis &&
+           PenaltyBreakScopeResolution == R.PenaltyBreakScopeResolution &&
            PenaltyBreakString == R.PenaltyBreakString &&
            PenaltyBreakTemplateDeclaration ==
                R.PenaltyBreakTemplateDeclaration &&
diff --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp
index ff5ed6c306f383b..d3e62c41098437c 100644
--- a/clang/lib/Format/Format.cpp
+++ b/clang/lib/Format/Format.cpp
@@ -1054,6 +1054,8 @@ template <> struct MappingTraits<FormatStyle> {
                    Style.PenaltyBreakFirstLessLess);
     IO.mapOptional("PenaltyBreakOpenParenthesis",
                    Style.PenaltyBreakOpenParenthesis);
+    IO.mapOptional("PenaltyBreakScopeResolution",
+                   Style.PenaltyBreakScopeResolution);
     IO.mapOptional("PenaltyBreakString", Style.PenaltyBreakString);
     IO.mapOptional("PenaltyBreakTemplateDeclaration",
                    Style.PenaltyBreakTemplateDeclaration);
@@ -1602,6 +1604,7 @@ FormatStyle getLLVMStyle(FormatStyle::LanguageKind Language) {
   LLVMStyle.PenaltyReturnTypeOnItsOwnLine = 60;
   LLVMStyle.PenaltyBreakBeforeFirstCallParameter = 19;
   LLVMStyle.PenaltyBreakOpenParenthesis = 0;
+  LLVMStyle.PenaltyBreakScopeResolution = 500;
   LLVMStyle.PenaltyBreakTemplateDeclaration = prec::Relational;
   LLVMStyle.PenaltyIndentedWhitespace = 0;
 
diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
index 24ce18a64348c1d..01a599db2e83c3b 100644
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -3765,7 +3765,7 @@ unsigned TokenAnnotator::splitPenalty(const AnnotatedLine &Line,
   }
 
   if (Left.is(tok::coloncolon))
-    return 500;
+    return Style.PenaltyBreakScopeResolution;
   if (Right.isOneOf(TT_StartOfName, TT_FunctionDeclarationName) ||
       Right.is(tok::kw_operator)) {
     if (Line.startsWith(tok::kw_for) && Right.PartOfMultiVariableDeclStmt)
diff --git a/clang/unittests/Format/ConfigParseTest.cpp b/clang/unittests/Format/ConfigParseTest.cpp
index 18ecba270e3455a..6c0f9ddac5ac8fd 100644
--- a/clang/unittests/Format/ConfigParseTest.cpp
+++ b/clang/unittests/Format/ConfigParseTest.cpp
@@ -255,6 +255,8 @@ TEST(ConfigParseTest, ParsesConfiguration) {
               PenaltyBreakTemplateDeclaration, 1234u);
   CHECK_PARSE("PenaltyBreakOpenParenthesis: 1234", PenaltyBreakOpenParenthesis,
               1234u);
+  CHECK_PARSE("PenaltyBreakScopeResolution: 1234", PenaltyBreakScopeResolution,
+              1234u);
   CHECK_PARSE("PenaltyExcessCharacter: 1234", PenaltyExcessCharacter, 1234u);
   CHECK_PARSE("PenaltyReturnTypeOnItsOwnLine: 1234",
               PenaltyReturnTypeOnItsOwnLine, 1234u);
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 340ae39cb22b036..263bbed3db13ff0 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -21567,6 +21567,19 @@ TEST_F(FormatTest, BreakPenaltyAfterForLoopLParen) {
                Style);
 }
 
+TEST_F(FormatTest, BreakPenaltyScopeResolution) {
+  FormatStyle Style = getLLVMStyle();
+  Style.ColumnLimit = 20;
+  Style.PenaltyExcessCharacter = 100;
+  verifyFormat("unsigned long\n"
+               "foo::bar();",
+               Style);
+  Style.PenaltyBreakScopeResolution = 10;
+  verifyFormat("unsigned long foo::\n"
+               "    bar();",
+               Style);
+}
+
 TEST_F(FormatTest, WorksFor8bitEncodings) {
   // FIXME: unstable test case
   EXPECT_EQ("\"\xce\xe4\xed\xe0\xe6\xe4\xfb \xe2 \"\n"