[clang] Revert "[clang-format] Annotate ::operator and Foo::operator correctly" (PR #164670)

[via cfe-commits]

https://github.com/PiJoules created https://github.com/llvm/llvm-project/pull/164670

Reverts llvm/llvm-project#164048

This led to a regression in clang-format where a space gets added in between the parameter type and `&`. For example, this

```
::test_anonymous::FunctionApplication& ::test_anonymous::FunctionApplication::operator=(const ::test_anonymous::FunctionApplication& other) noexcept {
```

becomes

```
::test_anonymous::FunctionApplication& ::test_anonymous::FunctionApplication::operator=(const ::test_anonymous::FunctionApplication & other) noexcept {
```

>From 2c8f6dd639e9d83b2f266d1f30ad3b0983f9d689 Mon Sep 17 00:00:00 2001
From: PiJoules <6019989+PiJoules at users.noreply.github.com>
Date: Wed, 22 Oct 2025 10:35:02 -0700
Subject: [PATCH] Revert "[clang-format] Annotate ::operator and Foo::operator
 correctly (#164048)"

This reverts commit 3bb9d4a24e40eea1988f6bdc6a79e7a128a2fad9.
---
 clang/lib/Format/TokenAnnotator.cpp           | 10 +++++++---
 clang/unittests/Format/TokenAnnotatorTest.cpp |  5 -----
 2 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
index c97a9e81eb59e..25971d2497f97 100644
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -3791,12 +3791,18 @@ static bool isFunctionDeclarationName(const LangOptions &LangOpts,
   if (Current.is(TT_FunctionDeclarationName))
     return true;
 
-  if (Current.isNoneOf(tok::identifier, tok::kw_operator))
+  if (!Current.Tok.getIdentifierInfo())
     return false;
 
   const auto *Prev = Current.getPreviousNonComment();
   assert(Prev);
 
+  if (Prev->is(tok::coloncolon))
+    Prev = Prev->Previous;
+
+  if (!Prev)
+    return false;
+
   const auto &Previous = *Prev;
 
   if (const auto *PrevPrev = Previous.getPreviousNonComment();
@@ -3845,8 +3851,6 @@ static bool isFunctionDeclarationName(const LangOptions &LangOpts,
 
   // Find parentheses of parameter list.
   if (Current.is(tok::kw_operator)) {
-    if (Line.startsWith(tok::kw_friend))
-      return true;
     if (Previous.Tok.getIdentifierInfo() &&
         Previous.isNoneOf(tok::kw_return, tok::kw_co_return)) {
       return true;
diff --git a/clang/unittests/Format/TokenAnnotatorTest.cpp b/clang/unittests/Format/TokenAnnotatorTest.cpp
index ca99940890984..f3637383a0a65 100644
--- a/clang/unittests/Format/TokenAnnotatorTest.cpp
+++ b/clang/unittests/Format/TokenAnnotatorTest.cpp
@@ -1129,11 +1129,6 @@ TEST_F(TokenAnnotatorTest, UnderstandsOverloadedOperators) {
   ASSERT_EQ(Tokens.size(), 7u) << Tokens;
   // Not TT_FunctionDeclarationName.
   EXPECT_TOKEN(Tokens[3], tok::kw_operator, TT_Unknown);
-
-  Tokens = annotate("SomeAPI::operator()();");
-  ASSERT_EQ(Tokens.size(), 9u) << Tokens;
-  // Not TT_FunctionDeclarationName.
-  EXPECT_TOKEN(Tokens[2], tok::kw_operator, TT_Unknown);
 }
 
 TEST_F(TokenAnnotatorTest, OverloadedOperatorInTemplate) {