[clang] [clang-format] Fix anonymous reference parameter with default value (PR #86254)

[via cfe-commits]

https://github.com/rayroudc updated https://github.com/llvm/llvm-project/pull/86254

>From bda7c429a4072e54b99d4fbd561fbd5d406692fd Mon Sep 17 00:00:00 2001
From: "C. Rayroud" <rayroudc at gmail.com>
Date: Mon, 18 Mar 2024 06:39:26 +0000
Subject: [PATCH] [clang-format] Fix anonymous reference parameter with default
 value

---
 clang/lib/Format/WhitespaceManager.cpp |  5 +++--
 clang/unittests/Format/FormatTest.cpp  | 20 ++++++++++++++++++++
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/clang/lib/Format/WhitespaceManager.cpp b/clang/lib/Format/WhitespaceManager.cpp
index 710bf8d8a8ec70..d06c42d5f4c5c5 100644
--- a/clang/lib/Format/WhitespaceManager.cpp
+++ b/clang/lib/Format/WhitespaceManager.cpp
@@ -464,10 +464,11 @@ AlignTokenSequence(const FormatStyle &Style, unsigned Start, unsigned End,
     if (i + 1 != Changes.size())
       Changes[i + 1].PreviousEndOfTokenColumn += Shift;
 
-    // If PointerAlignment is PAS_Right, keep *s or &s next to the token
+    // If PointerAlignment is PAS_Right, keep *s or &s next to the token,
+    // except if the token is equal, then a space is needed.
     if ((Style.PointerAlignment == FormatStyle::PAS_Right ||
          Style.ReferenceAlignment == FormatStyle::RAS_Right) &&
-        CurrentChange.Spaces != 0) {
+        CurrentChange.Spaces != 0 && CurrentChange.Tok->isNot(tok::equal)) {
       const bool ReferenceNotRightAligned =
           Style.ReferenceAlignment != FormatStyle::RAS_Right &&
           Style.ReferenceAlignment != FormatStyle::RAS_Pointer;
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 03005384a6f667..d1e977dfa66af5 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -19066,6 +19066,11 @@ TEST_F(FormatTest, AlignConsecutiveDeclarations) {
   verifyFormat("int    a(int x);\n"
                "double b();",
                Alignment);
+  verifyFormat("int    a(const Test & = Test());\n"
+               "int    a1(int &foo, const Test & = Test());\n"
+               "int    a2(int &foo, const Test &name = Test());\n"
+               "double b();",
+               Alignment);
   verifyFormat("struct Test {\n"
                "  Test(const Test &) = default;\n"
                "  ~Test() = default;\n"
@@ -19102,6 +19107,13 @@ TEST_F(FormatTest, AlignConsecutiveDeclarations) {
                "    int  x,\n"
                "    bool y);",
                Alignment);
+  // Set ColumnLimit low so that we break the argument list in multiple lines.
+  Alignment.ColumnLimit = 35;
+  verifyFormat("int    a3(SomeTypeName1 &x,\n"
+               "          SomeTypeName2 &y,\n"
+               "          const Test & = Test());\n"
+               "double b();",
+               Alignment);
   Alignment.ColumnLimit = OldColumnLimit;
   // Ensure function pointers don't screw up recursive alignment
   verifyFormat("int    a(int x, void (*fp)(int y));\n"
@@ -19287,6 +19299,10 @@ TEST_F(FormatTest, AlignConsecutiveDeclarations) {
                "int    foobar;",
                AlignmentLeft);
 
+  verifyFormat("int    a(SomeType& foo, const Test& = Test());\n"
+               "double b();",
+               AlignmentLeft);
+
   // PAS_Middle
   FormatStyle AlignmentMiddle = Alignment;
   AlignmentMiddle.PointerAlignment = FormatStyle::PAS_Middle;
@@ -19347,6 +19363,10 @@ TEST_F(FormatTest, AlignConsecutiveDeclarations) {
                "int     foobar;",
                AlignmentMiddle);
 
+  verifyFormat("int    a(SomeType & foo, const Test & = Test());\n"
+               "double b();",
+               AlignmentMiddle);
+
   Alignment.AlignConsecutiveAssignments.Enabled = false;
   Alignment.AlignEscapedNewlines = FormatStyle::ENAS_DontAlign;
   verifyFormat("#define A \\\n"