From c7ac782942f15cc38858965b435b9e10db38b757 Mon Sep 17 00:00:00 2001
From: James Y Knight <jyknight@google.com>
Date: Fri, 25 Jul 2025 11:55:50 -0400
Subject: [PATCH] [clang-format] Google Style: disable DerivePointerAlignment.
 (#149602)

The [Google C++ Style
Guide](https://google.github.io/styleguide/cppguide.html#Pointer_and_Reference_Expressions)
is being changed to specify that spaces should go after the
asterisk/ampersand, rather than permitting either before or after on a
file-by-file basis.

The new requirement is:
> When referring to a pointer or reference (variable declarations or
> definitions, arguments, return types, template parameters, etc.),
> you must not place a space before the asterisk/ampersand. Use a
> space to separate the type from the declared name (if present).

The [Google ObjC
style](https://google.github.io/styleguide/objcguide.html) is silent on
this matter, but the de-facto style is not being modified at this time.
So, keep DerivePointerAlignment enabled for ObjC language mode.

(cherry picked from commit 9281797a577b7954521fb9192d41e457ca2ca42e)
---
 clang/lib/Format/Format.cpp           |  2 +-
 clang/unittests/Format/FormatTest.cpp | 22 +++++++++++++---------
 2 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp
index 0e92c93ea1dde..513fcfcd41258 100644
--- a/clang/lib/Format/Format.cpp
+++ b/clang/lib/Format/Format.cpp
@@ -1749,7 +1749,6 @@ FormatStyle getGoogleStyle(FormatStyle::LanguageKind Language) {
   GoogleStyle.AttributeMacros.push_back("absl_nullable");
   GoogleStyle.AttributeMacros.push_back("absl_nullability_unknown");
   GoogleStyle.BreakTemplateDeclarations = FormatStyle::BTDS_Yes;
-  GoogleStyle.DerivePointerAlignment = true;
   GoogleStyle.IncludeStyle.IncludeBlocks = tooling::IncludeStyle::IBS_Regroup;
   GoogleStyle.IncludeStyle.IncludeCategories = {{"^<ext/.*\\.h>", 2, 0, false},
                                                 {"^<.*\\.h>", 1, 0, false},
@@ -1858,6 +1857,7 @@ FormatStyle getGoogleStyle(FormatStyle::LanguageKind Language) {
   } else if (Language == FormatStyle::LK_ObjC) {
     GoogleStyle.AlwaysBreakBeforeMultilineStrings = false;
     GoogleStyle.ColumnLimit = 100;
+    GoogleStyle.DerivePointerAlignment = true;
     // "Regroup" doesn't work well for ObjC yet (main header heuristic,
     // relationship between ObjC standard library headers and other heades,
     // #imports, etc.)
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index f9eedcb8f12af..e161f61e8864e 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -8571,10 +8571,10 @@ TEST_F(FormatTest, BreaksFunctionDeclarations) {
                "operator<<(const SomeLooooooooooooooooooooooooogType &other);");
   verifyGoogleFormat(
       "SomeLoooooooooooooooooooooooooooooogType operator>>(\n"
-      "    const SomeLooooooooogType &a, const SomeLooooooooogType &b);");
+      "    const SomeLooooooooogType& a, const SomeLooooooooogType& b);");
   verifyGoogleFormat(
       "SomeLoooooooooooooooooooooooooooooogType operator<<(\n"
-      "    const SomeLooooooooogType &a, const SomeLooooooooogType &b);");
+      "    const SomeLooooooooogType& a, const SomeLooooooooogType& b);");
 
   verifyFormat("void aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa(\n"
                "    int aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa = 1);");
@@ -8583,7 +8583,7 @@ TEST_F(FormatTest, BreaksFunctionDeclarations) {
   verifyGoogleFormat(
       "typename aaaaaaaaaa<aaaaaa>::aaaaaaaaaaa\n"
       "aaaaaaaaaa<aaaaaa>::aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa(\n"
-      "    bool *aaaaaaaaaaaaaaaaaa, bool *aa) {}");
+      "    bool* aaaaaaaaaaaaaaaaaa, bool* aa) {}");
   verifyGoogleFormat("template <typename T>\n"
                      "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\n"
                      "aaaaaaaaaaaaaaaaaaaaaaa<T>::aaaaaaaaaaaaa(\n"
@@ -12891,27 +12891,31 @@ TEST_F(FormatTest, UnderstandsEllipsis) {
 }
 
 TEST_F(FormatTest, AdaptivelyFormatsPointersAndReferences) {
+  auto Style = getGoogleStyle();
+  EXPECT_FALSE(Style.DerivePointerAlignment);
+  Style.DerivePointerAlignment = true;
+
   verifyFormat("int *a;\n"
                "int *a;\n"
                "int *a;",
                "int *a;\n"
                "int* a;\n"
                "int *a;",
-               getGoogleStyle());
+               Style);
   verifyFormat("int* a;\n"
                "int* a;\n"
                "int* a;",
                "int* a;\n"
                "int* a;\n"
                "int *a;",
-               getGoogleStyle());
+               Style);
   verifyFormat("int *a;\n"
                "int *a;\n"
                "int *a;",
                "int *a;\n"
                "int * a;\n"
                "int *  a;",
-               getGoogleStyle());
+               Style);
   verifyFormat("auto x = [] {\n"
                "  int *a;\n"
                "  int *a;\n"
@@ -12920,7 +12924,7 @@ TEST_F(FormatTest, AdaptivelyFormatsPointersAndReferences) {
                "auto x=[]{int *a;\n"
                "int * a;\n"
                "int *  a;};",
-               getGoogleStyle());
+               Style);
 }
 
 TEST_F(FormatTest, UnderstandsRvalueReferences) {
@@ -13056,7 +13060,7 @@ TEST_F(FormatTest, FormatsCasts) {
   verifyFormat("virtual void foo(char &) const;");
   verifyFormat("virtual void foo(int *a, char *) const;");
   verifyFormat("int a = sizeof(int *) + b;");
-  verifyGoogleFormat("int a = alignof(int *) + b;");
+  verifyGoogleFormat("int a = alignof(int*) + b;");
   verifyFormat("bool b = f(g<int>) && c;");
   verifyFormat("typedef void (*f)(int i) func;");
   verifyFormat("void operator++(int) noexcept;");
@@ -25425,7 +25429,7 @@ TEST_F(FormatTest, AtomicQualifier) {
   verifyFormat("struct foo {\n"
                "  int a1;\n"
                "  _Atomic(a) a2;\n"
-               "  _Atomic(_Atomic(int) *const) a3;\n"
+               "  _Atomic(_Atomic(int)* const) a3;\n"
                "};",
                Google);
   verifyFormat("_Atomic(uint64_t) a;");