From b7d665bf49d20faf9bb22f782503391dcc361cab Mon Sep 17 00:00:00 2001
From: denzor200 <denismikhaylov38@gmail.com>
Date: Sun, 16 Nov 2025 23:56:06 +0300
Subject: [PATCH 01/19] Implementation template from DeepSeek

---
 .../clang-tidy/misc/CMakeLists.txt            |   1 +
 .../clang-tidy/misc/MiscTidyModule.cpp        |   3 +
 .../misc/ShadowedNamespaceFunctionCheck.cpp   | 131 ++++++++++++++++++
 .../misc/ShadowedNamespaceFunctionCheck.h     |  39 ++++++
 clang-tools-extra/docs/ReleaseNotes.rst       |   5 +
 .../docs/clang-tidy/checks/list.rst           |   2 +
 .../misc/shadowed-namespace-function.rst      |   6 +
 .../misc/shadowed-namespace-function.cpp      |  13 ++
 8 files changed, 200 insertions(+)
 create mode 100644 clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp
 create mode 100644 clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.h
 create mode 100644 clang-tools-extra/docs/clang-tidy/checks/misc/shadowed-namespace-function.rst
 create mode 100644 clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function.cpp

diff --git a/clang-tools-extra/clang-tidy/misc/CMakeLists.txt b/clang-tools-extra/clang-tidy/misc/CMakeLists.txt
index 6214ee92927f2..d18af237283ff 100644
--- a/clang-tools-extra/clang-tidy/misc/CMakeLists.txt
+++ b/clang-tools-extra/clang-tidy/misc/CMakeLists.txt
@@ -34,6 +34,7 @@ add_clang_library(clangTidyMiscModule STATIC
   NonPrivateMemberVariablesInClassesCheck.cpp
   OverrideWithDifferentVisibilityCheck.cpp
   RedundantExpressionCheck.cpp
+  ShadowedNamespaceFunctionCheck.cpp
   StaticAssertCheck.cpp
   ThrowByValueCatchByReferenceCheck.cpp
   UnconventionalAssignOperatorCheck.cpp
diff --git a/clang-tools-extra/clang-tidy/misc/MiscTidyModule.cpp b/clang-tools-extra/clang-tidy/misc/MiscTidyModule.cpp
index 347fa2a82e43c..2706fe647fe14 100644
--- a/clang-tools-extra/clang-tidy/misc/MiscTidyModule.cpp
+++ b/clang-tools-extra/clang-tidy/misc/MiscTidyModule.cpp
@@ -24,6 +24,7 @@
 #include "NonPrivateMemberVariablesInClassesCheck.h"
 #include "OverrideWithDifferentVisibilityCheck.h"
 #include "RedundantExpressionCheck.h"
+#include "ShadowedNamespaceFunctionCheck.h"
 #include "StaticAssertCheck.h"
 #include "ThrowByValueCatchByReferenceCheck.h"
 #include "UnconventionalAssignOperatorCheck.h"
@@ -65,6 +66,8 @@ class MiscModule : public ClangTidyModule {
         "misc-non-private-member-variables-in-classes");
     CheckFactories.registerCheck<RedundantExpressionCheck>(
         "misc-redundant-expression");
+    CheckFactories.registerCheck<ShadowedNamespaceFunctionCheck>(
+        "misc-shadowed-namespace-function");
     CheckFactories.registerCheck<StaticAssertCheck>("misc-static-assert");
     CheckFactories.registerCheck<ThrowByValueCatchByReferenceCheck>(
         "misc-throw-by-value-catch-by-reference");
diff --git a/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp b/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp
new file mode 100644
index 0000000000000..d9fcfccfb85fb
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp
@@ -0,0 +1,131 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "ShadowedNamespaceFunctionCheck.h"
+#include "../utils/FixItHintUtils.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
+#include "clang/AST/Decl.h"
+#include "clang/AST/DeclCXX.h"
+
+using namespace clang;
+using namespace clang::ast_matchers;
+using namespace clang::tidy;
+
+namespace clang {
+namespace tidy {
+namespace misc {
+
+void ShadowedNamespaceFunctionCheck::registerMatchers(MatchFinder *Finder) {
+  // Simple matcher for all function definitions
+  Finder->addMatcher(
+      functionDecl(
+          isDefinition()
+      ).bind("func"),
+      this
+  );
+}
+
+void ShadowedNamespaceFunctionCheck::check(
+    const MatchFinder::MatchResult &Result) {
+  const auto *Func = Result.Nodes.getNodeAs<FunctionDecl>("func");
+  
+  if (!Func || !Result.SourceManager)
+    return;
+
+  // Skip if not in global namespace
+  const DeclContext *DC = Func->getDeclContext();
+  if (!DC->isTranslationUnit())
+    return;
+
+  // Skip templates, static functions, main, etc.
+  if (Func->isTemplated() || Func->isStatic() || 
+      Func->getName() == "main" || Func->isImplicit())
+    return;
+
+  std::string FuncName = Func->getNameAsString();
+  if (FuncName.empty())
+    return;
+
+  ASTContext *Context = Result.Context;
+
+  // Look for functions with the same name in namespaces
+  const FunctionDecl *ShadowedFunc = nullptr;
+  const NamespaceDecl *ShadowedNamespace = nullptr;
+
+  // Traverse all declarations in the translation unit
+  for (const auto *Decl : Context->getTranslationUnitDecl()->decls()) {
+    if (const auto *NS = dyn_cast<NamespaceDecl>(Decl)) {
+      findShadowedInNamespace(NS, Func, FuncName, ShadowedFunc, ShadowedNamespace);
+      if (ShadowedFunc) break;
+    }
+  }
+
+  if (!ShadowedFunc || !ShadowedNamespace)
+    return;
+
+  // Generate warning message
+  std::string NamespaceName = ShadowedNamespace->getNameAsString();
+  auto Diag = diag(Func->getLocation(), 
+                   "free function %0 shadows %1::%2")
+              << Func->getDeclName() 
+              << NamespaceName 
+              << ShadowedFunc->getDeclName();
+
+  // Generate fixit hint to add namespace qualification
+  SourceLocation NameLoc = Func->getLocation();
+  if (NameLoc.isValid()) {
+    std::string Fix = NamespaceName + "::";
+    Diag << FixItHint::CreateInsertion(NameLoc, Fix);
+  }
+
+  // Note: Also show where the shadowed function is declared
+  diag(ShadowedFunc->getLocation(), 
+       "function %0 declared here", DiagnosticIDs::Note)
+      << ShadowedFunc->getDeclName();
+}
+
+void ShadowedNamespaceFunctionCheck::findShadowedInNamespace(
+    const NamespaceDecl *NS, 
+    const FunctionDecl *GlobalFunc,
+    const std::string &GlobalFuncName,
+    const FunctionDecl *&ShadowedFunc,
+    const NamespaceDecl *&ShadowedNamespace) {
+  
+  // Skip anonymous namespaces
+  if (NS->isAnonymousNamespace())
+    return;
+
+  for (const auto *Decl : NS->decls()) {
+    // Check nested namespaces
+    if (const auto *NestedNS = dyn_cast<NamespaceDecl>(Decl)) {
+      findShadowedInNamespace(NestedNS, GlobalFunc, GlobalFuncName, 
+                             ShadowedFunc, ShadowedNamespace);
+      if (ShadowedFunc) return;
+    }
+
+    // Check functions
+    if (const auto *Func = dyn_cast<FunctionDecl>(Decl)) {
+      // Skip if it's the same function, templates, or definitions
+      if (Func == GlobalFunc || Func->isTemplated() || 
+          Func->isThisDeclarationADefinition())
+        continue;
+
+      if (Func->getNameAsString() == GlobalFuncName) {
+        ShadowedFunc = Func;
+        ShadowedNamespace = NS;
+        return;
+      }
+    }
+  }
+}
+
+} // namespace misc
+} // namespace tidy
+} // namespace clang
+
diff --git a/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.h b/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.h
new file mode 100644
index 0000000000000..e3383f6f06332
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.h
@@ -0,0 +1,39 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MISC_SHADOWEDNAMESPACEFUNCTIONCHECK_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MISC_SHADOWEDNAMESPACEFUNCTIONCHECK_H
+
+#include "../ClangTidyCheck.h"
+
+namespace clang::tidy::misc {
+
+/// FIXME: Write a short description.
+///
+/// For the user-facing documentation see:
+/// https://clang.llvm.org/extra/clang-tidy/checks/misc/shadowed-namespace-function.html
+class ShadowedNamespaceFunctionCheck : public ClangTidyCheck {
+public:
+  ShadowedNamespaceFunctionCheck(StringRef Name, ClangTidyContext *Context)
+      : ClangTidyCheck(Name, Context) {}
+  void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+  void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+  bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {
+    return LangOpts.CPlusPlus;
+  }
+private:
+  void findShadowedInNamespace(const NamespaceDecl *NS,
+                               const FunctionDecl *GlobalFunc,
+                               const std::string &GlobalFuncName,
+                               const FunctionDecl *&ShadowedFunc,
+                               const NamespaceDecl *&ShadowedNamespace);
+};
+
+} // namespace clang::tidy::misc
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MISC_SHADOWEDNAMESPACEFUNCTIONCHECK_H
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 666865cfb2fcd..33a6919c2f9c8 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -226,6 +226,11 @@ New checks
   Finds virtual function overrides with different visibility than the function
   in the base class.
 
+- New :doc:`misc-shadowed-namespace-function
+  <clang-tidy/checks/misc/shadowed-namespace-function>` check.
+
+  FIXME: Write a short description.
+
 - New :doc:`readability-redundant-parentheses
   <clang-tidy/checks/readability/redundant-parentheses>` check.
 
diff --git a/clang-tools-extra/docs/clang-tidy/checks/list.rst b/clang-tools-extra/docs/clang-tidy/checks/list.rst
index e2875604af72b..4e8b752968e38 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/list.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/list.rst
@@ -277,6 +277,8 @@ Clang-Tidy Checks
    :doc:`misc-non-private-member-variables-in-classes <misc/non-private-member-variables-in-classes>`,
    :doc:`misc-override-with-different-visibility <misc/override-with-different-visibility>`,
    :doc:`misc-redundant-expression <misc/redundant-expression>`, "Yes"
+   :doc:`misc-shadowed-namespace-function <misc/shadowed-namespace-function>`, "Yes"
+   :doc:`misc-shadowed-namespace-function <misc/shadowed-namespace-function>`, "Yes"
    :doc:`misc-static-assert <misc/static-assert>`, "Yes"
    :doc:`misc-throw-by-value-catch-by-reference <misc/throw-by-value-catch-by-reference>`,
    :doc:`misc-unconventional-assign-operator <misc/unconventional-assign-operator>`,
diff --git a/clang-tools-extra/docs/clang-tidy/checks/misc/shadowed-namespace-function.rst b/clang-tools-extra/docs/clang-tidy/checks/misc/shadowed-namespace-function.rst
new file mode 100644
index 0000000000000..46367e56563cc
--- /dev/null
+++ b/clang-tools-extra/docs/clang-tidy/checks/misc/shadowed-namespace-function.rst
@@ -0,0 +1,6 @@
+.. title:: clang-tidy - misc-shadowed-namespace-function
+
+misc-shadowed-namespace-function
+================================
+
+FIXME: Describe what patterns does the check detect and why. Give examples.
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function.cpp
new file mode 100644
index 0000000000000..9f7af24cb4240
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function.cpp
@@ -0,0 +1,13 @@
+// RUN: %check_clang_tidy %s misc-shadowed-namespace-function %t
+
+void f1();
+namespace foo {
+  void f0();
+  void f1();
+}
+void f0() {}
+// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: free function 'f0' shadows foo::f0 [misc-shadowed-namespace-function]
+// CHECK-FIXES: void foo::f0() {}
+void f1() {}
+// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: free function 'f1' shadows foo::f1 [misc-shadowed-namespace-function]
+// CHECK-MESSAGES-NOT: :[[@LINE-2]]:{{.*}}: note: FIX-IT applied suggested code changes

From e9de03d1438e7bfd59a6b89c7695421ea74c9583 Mon Sep 17 00:00:00 2001
From: denzor200 <denismikhaylov38@gmail.com>
Date: Sun, 16 Nov 2025 23:56:19 +0300
Subject: [PATCH 02/19] fix unit-test

---
 .../clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp      | 6 +++---
 .../checkers/misc/shadowed-namespace-function.cpp           | 4 ++--
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp b/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp
index d9fcfccfb85fb..b006c5ef44763 100644
--- a/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp
+++ b/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp
@@ -72,14 +72,14 @@ void ShadowedNamespaceFunctionCheck::check(
   // Generate warning message
   std::string NamespaceName = ShadowedNamespace->getNameAsString();
   auto Diag = diag(Func->getLocation(), 
-                   "free function %0 shadows %1::%2")
+                   "free function %0 shadows '%1::%2'")
               << Func->getDeclName() 
               << NamespaceName 
-              << ShadowedFunc->getDeclName();
+              << ShadowedFunc->getDeclName().getAsString();
 
   // Generate fixit hint to add namespace qualification
   SourceLocation NameLoc = Func->getLocation();
-  if (NameLoc.isValid()) {
+  if (NameLoc.isValid() && !Func->getPreviousDecl()) {
     std::string Fix = NamespaceName + "::";
     Diag << FixItHint::CreateInsertion(NameLoc, Fix);
   }
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function.cpp
index 9f7af24cb4240..920556cca0381 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function.cpp
@@ -6,8 +6,8 @@ namespace foo {
   void f1();
 }
 void f0() {}
-// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: free function 'f0' shadows foo::f0 [misc-shadowed-namespace-function]
+// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: free function 'f0' shadows 'foo::f0' [misc-shadowed-namespace-function]
 // CHECK-FIXES: void foo::f0() {}
 void f1() {}
-// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: free function 'f1' shadows foo::f1 [misc-shadowed-namespace-function]
+// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: free function 'f1' shadows 'foo::f1' [misc-shadowed-namespace-function]
 // CHECK-MESSAGES-NOT: :[[@LINE-2]]:{{.*}}: note: FIX-IT applied suggested code changes

From 199ecec95322a37b95d8138bdd3df296241a34e4 Mon Sep 17 00:00:00 2001
From: denzor200 <denismikhaylov38@gmail.com>
Date: Mon, 17 Nov 2025 00:03:28 +0300
Subject: [PATCH 03/19] Docs written by DeepSeek

---
 .../misc/shadowed-namespace-function.rst      | 42 ++++++++++++++++++-
 1 file changed, 41 insertions(+), 1 deletion(-)

diff --git a/clang-tools-extra/docs/clang-tidy/checks/misc/shadowed-namespace-function.rst b/clang-tools-extra/docs/clang-tidy/checks/misc/shadowed-namespace-function.rst
index 46367e56563cc..b31455cfa0c31 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/misc/shadowed-namespace-function.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/misc/shadowed-namespace-function.rst
@@ -3,4 +3,44 @@
 misc-shadowed-namespace-function
 ================================
 
-FIXME: Describe what patterns does the check detect and why. Give examples.
+Detects free functions in the global namespace that shadow functions declared 
+in other namespaces. This check helps prevent accidental shadowing of namespace
+functions, which can lead to confusion about which function is being called and
+potential linking errors.
+
+Examples
+--------
+
+.. code-block:: c++
+
+  namespace utils {
+    void process();
+    void calculate();
+  }
+
+  // Warning: free function shadows utils::process
+  void process() {} 
+
+  // No warning - static function
+  static void calculate() {}
+
+The check will suggest adding the appropriate namespace qualification:
+
+.. code-block:: diff
+
+  - void process() {}
+  + void utils::process() {}
+
+Options
+-------
+
+None
+
+Limitations
+-----------
+
+- Does not warn about functions in anonymous namespaces
+- Does not warn about template functions
+- Does not warn about static functions or member functions
+- Does not warn about the ``main`` function
+- Only considers functions declared before the global definition

From 8018941598da61c57338f80407b8fa39ded3a923 Mon Sep 17 00:00:00 2001
From: denzor200 <denismikhaylov38@gmail.com>
Date: Mon, 17 Nov 2025 00:11:33 +0300
Subject: [PATCH 04/19] short description by DeepSeek

---
 .../clang-tidy/misc/ShadowedNamespaceFunctionCheck.h            | 2 +-
 clang-tools-extra/docs/ReleaseNotes.rst                         | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.h b/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.h
index e3383f6f06332..61f4cf8ed1c49 100644
--- a/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.h
+++ b/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.h
@@ -13,7 +13,7 @@
 
 namespace clang::tidy::misc {
 
-/// FIXME: Write a short description.
+/// Detects free functions in global namespace that shadow functions from other namespaces.
 ///
 /// For the user-facing documentation see:
 /// https://clang.llvm.org/extra/clang-tidy/checks/misc/shadowed-namespace-function.html
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 33a6919c2f9c8..a1482d89b6042 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -229,7 +229,7 @@ New checks
 - New :doc:`misc-shadowed-namespace-function
   <clang-tidy/checks/misc/shadowed-namespace-function>` check.
 
-  FIXME: Write a short description.
+  Detects free functions in global namespace that shadow functions from other namespaces.
 
 - New :doc:`readability-redundant-parentheses
   <clang-tidy/checks/readability/redundant-parentheses>` check.

From 320f6c765fe6288d2956d4b4498edf2d2d76b93f Mon Sep 17 00:00:00 2001
From: denzor200 <denismikhaylov38@gmail.com>
Date: Mon, 17 Nov 2025 00:12:49 +0300
Subject: [PATCH 05/19] fix list.rst

---
 clang-tools-extra/docs/clang-tidy/checks/list.rst | 1 -
 1 file changed, 1 deletion(-)

diff --git a/clang-tools-extra/docs/clang-tidy/checks/list.rst b/clang-tools-extra/docs/clang-tidy/checks/list.rst
index 4e8b752968e38..473d82033758f 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/list.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/list.rst
@@ -278,7 +278,6 @@ Clang-Tidy Checks
    :doc:`misc-override-with-different-visibility <misc/override-with-different-visibility>`,
    :doc:`misc-redundant-expression <misc/redundant-expression>`, "Yes"
    :doc:`misc-shadowed-namespace-function <misc/shadowed-namespace-function>`, "Yes"
-   :doc:`misc-shadowed-namespace-function <misc/shadowed-namespace-function>`, "Yes"
    :doc:`misc-static-assert <misc/static-assert>`, "Yes"
    :doc:`misc-throw-by-value-catch-by-reference <misc/throw-by-value-catch-by-reference>`,
    :doc:`misc-unconventional-assign-operator <misc/unconventional-assign-operator>`,

From 5994fc0d21f12fd6bdb629409329599eb2974165 Mon Sep 17 00:00:00 2001
From: denzor200 <denismikhaylov38@gmail.com>
Date: Mon, 17 Nov 2025 00:45:46 +0300
Subject: [PATCH 06/19] more tests && fix the doc

---
 .../misc/ShadowedNamespaceFunctionCheck.cpp        |  2 +-
 .../checks/misc/shadowed-namespace-function.rst    |  1 -
 ...owed-namespace-function-anonymous-namespace.cpp | 11 +++++++++++
 .../misc/shadowed-namespace-function-nested.cpp    | 13 +++++++++++++
 .../misc/shadowed-namespace-function-static.cpp    |  9 +++++++++
 .../misc/shadowed-namespace-function-template.cpp  | 14 ++++++++++++++
 6 files changed, 48 insertions(+), 2 deletions(-)
 create mode 100644 clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-anonymous-namespace.cpp
 create mode 100644 clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-nested.cpp
 create mode 100644 clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-static.cpp
 create mode 100644 clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-template.cpp

diff --git a/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp b/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp
index b006c5ef44763..b0324ab79aab5 100644
--- a/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp
+++ b/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp
@@ -70,7 +70,7 @@ void ShadowedNamespaceFunctionCheck::check(
     return;
 
   // Generate warning message
-  std::string NamespaceName = ShadowedNamespace->getNameAsString();
+  std::string NamespaceName = ShadowedNamespace->getQualifiedNameAsString();
   auto Diag = diag(Func->getLocation(), 
                    "free function %0 shadows '%1::%2'")
               << Func->getDeclName() 
diff --git a/clang-tools-extra/docs/clang-tidy/checks/misc/shadowed-namespace-function.rst b/clang-tools-extra/docs/clang-tidy/checks/misc/shadowed-namespace-function.rst
index b31455cfa0c31..b82317fd0a748 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/misc/shadowed-namespace-function.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/misc/shadowed-namespace-function.rst
@@ -43,4 +43,3 @@ Limitations
 - Does not warn about template functions
 - Does not warn about static functions or member functions
 - Does not warn about the ``main`` function
-- Only considers functions declared before the global definition
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-anonymous-namespace.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-anonymous-namespace.cpp
new file mode 100644
index 0000000000000..1689843464ae1
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-anonymous-namespace.cpp
@@ -0,0 +1,11 @@
+// RUN: %check_clang_tidy %s misc-shadowed-namespace-function %t
+
+namespace { void f1(); }
+namespace foo {
+  void f0();
+  void f1();
+}
+namespace {
+void f0() {}
+void f1() {}
+}
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-nested.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-nested.cpp
new file mode 100644
index 0000000000000..41b130624bbaa
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-nested.cpp
@@ -0,0 +1,13 @@
+// RUN: %check_clang_tidy %s misc-shadowed-namespace-function %t
+
+void f1();
+namespace foo::foo2::foo3 {
+  void f0();
+  void f1();
+}
+void f0() {}
+// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: free function 'f0' shadows 'foo::foo2::foo3::f0' [misc-shadowed-namespace-function]
+// CHECK-FIXES: void foo::foo2::foo3::f0() {}
+void f1() {}
+// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: free function 'f1' shadows 'foo::foo2::foo3::f1' [misc-shadowed-namespace-function]
+// CHECK-MESSAGES-NOT: :[[@LINE-2]]:{{.*}}: note: FIX-IT applied suggested code changes
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-static.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-static.cpp
new file mode 100644
index 0000000000000..d1371c044d112
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-static.cpp
@@ -0,0 +1,9 @@
+// RUN: %check_clang_tidy %s misc-shadowed-namespace-function %t
+
+static void f1();
+namespace foo {
+  void f0();
+  void f1();
+}
+static void f0() {}
+static void f1() {}
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-template.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-template.cpp
new file mode 100644
index 0000000000000..48924fcdb932d
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-template.cpp
@@ -0,0 +1,14 @@
+// RUN: %check_clang_tidy %s misc-shadowed-namespace-function %t
+
+template<typename T>
+void f1();
+namespace foo {
+  template<typename T>
+  void f0();
+  template<typename T>
+  void f1();
+}
+template<typename T>
+void f0() {}
+template<typename T>
+void f1() {}

From 4112759aea418b33204f8f19f571657c1f53ffdf Mon Sep 17 00:00:00 2001
From: denzor200 <denismikhaylov38@gmail.com>
Date: Mon, 17 Nov 2025 00:53:00 +0300
Subject: [PATCH 07/19] fix invalid fixit for correctly defined function

---
 .../misc/ShadowedNamespaceFunctionCheck.cpp           |  3 +++
 .../misc/shadowed-namespace-function-good.cpp         |  9 +++++++++
 .../misc/shadowed-namespace-function-good2.cpp        | 11 +++++++++++
 3 files changed, 23 insertions(+)
 create mode 100644 clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-good.cpp
 create mode 100644 clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-good2.cpp

diff --git a/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp b/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp
index b0324ab79aab5..ca095771c477a 100644
--- a/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp
+++ b/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp
@@ -69,6 +69,9 @@ void ShadowedNamespaceFunctionCheck::check(
   if (!ShadowedFunc || !ShadowedNamespace)
     return;
 
+  if (ShadowedFunc->getDefinition())
+    return;
+
   // Generate warning message
   std::string NamespaceName = ShadowedNamespace->getQualifiedNameAsString();
   auto Diag = diag(Func->getLocation(), 
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-good.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-good.cpp
new file mode 100644
index 0000000000000..17abae5e943b6
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-good.cpp
@@ -0,0 +1,9 @@
+// RUN: %check_clang_tidy %s misc-shadowed-namespace-function %t
+
+void f1();
+namespace foo {
+  void f0() {}
+  void f1() {}
+}
+void f0() {}
+void f1() {}
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-good2.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-good2.cpp
new file mode 100644
index 0000000000000..b3218afa60e9d
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-good2.cpp
@@ -0,0 +1,11 @@
+// RUN: %check_clang_tidy %s misc-shadowed-namespace-function %t
+
+void f1();
+namespace foo {
+  void f0();
+  void f1();
+}
+void foo::f0() {}
+void foo::f1() {}
+void f0() {}
+void f1() {}

From 89029b766d465aeda8bcdc21a6b092bf73239630 Mon Sep 17 00:00:00 2001
From: denzor200 <denismikhaylov38@gmail.com>
Date: Mon, 17 Nov 2025 00:57:41 +0300
Subject: [PATCH 08/19] more unit-test

---
 .../checkers/misc/shadowed-namespace-function-main.cpp      | 6 ++++++
 1 file changed, 6 insertions(+)
 create mode 100644 clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-main.cpp

diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-main.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-main.cpp
new file mode 100644
index 0000000000000..4321486ba7101
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-main.cpp
@@ -0,0 +1,6 @@
+// RUN: %check_clang_tidy %s misc-shadowed-namespace-function %t
+
+namespace foo {
+  int main();
+}
+int main() {}

From 34dc72a0bd3a34bed5b55703f189550599b4ac0d Mon Sep 17 00:00:00 2001
From: denzor200 <denismikhaylov38@gmail.com>
Date: Mon, 17 Nov 2025 01:48:47 +0300
Subject: [PATCH 09/19] refactoring

---
 .../misc/ShadowedNamespaceFunctionCheck.cpp   | 33 +++++++++----------
 .../misc/ShadowedNamespaceFunctionCheck.h     | 10 +++---
 2 files changed, 20 insertions(+), 23 deletions(-)

diff --git a/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp b/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp
index ca095771c477a..669d6793e23cd 100644
--- a/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp
+++ b/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp
@@ -45,14 +45,14 @@ void ShadowedNamespaceFunctionCheck::check(
 
   // Skip templates, static functions, main, etc.
   if (Func->isTemplated() || Func->isStatic() || 
-      Func->getName() == "main" || Func->isImplicit())
+      Func->isMain() || Func->isImplicit())
     return;
 
-  std::string FuncName = Func->getNameAsString();
+  const std::string FuncName = Func->getNameAsString();
   if (FuncName.empty())
     return;
 
-  ASTContext *Context = Result.Context;
+  const ASTContext *Context = Result.Context;
 
   // Look for functions with the same name in namespaces
   const FunctionDecl *ShadowedFunc = nullptr;
@@ -61,7 +61,7 @@ void ShadowedNamespaceFunctionCheck::check(
   // Traverse all declarations in the translation unit
   for (const auto *Decl : Context->getTranslationUnitDecl()->decls()) {
     if (const auto *NS = dyn_cast<NamespaceDecl>(Decl)) {
-      findShadowedInNamespace(NS, Func, FuncName, ShadowedFunc, ShadowedNamespace);
+      std::tie(ShadowedFunc, ShadowedNamespace) = findShadowedInNamespace(NS, Func, FuncName);
       if (ShadowedFunc) break;
     }
   }
@@ -73,7 +73,7 @@ void ShadowedNamespaceFunctionCheck::check(
     return;
 
   // Generate warning message
-  std::string NamespaceName = ShadowedNamespace->getQualifiedNameAsString();
+  const std::string NamespaceName = ShadowedNamespace->getQualifiedNameAsString();
   auto Diag = diag(Func->getLocation(), 
                    "free function %0 shadows '%1::%2'")
               << Func->getDeclName() 
@@ -81,9 +81,9 @@ void ShadowedNamespaceFunctionCheck::check(
               << ShadowedFunc->getDeclName().getAsString();
 
   // Generate fixit hint to add namespace qualification
-  SourceLocation NameLoc = Func->getLocation();
+  const SourceLocation NameLoc = Func->getLocation();
   if (NameLoc.isValid() && !Func->getPreviousDecl()) {
-    std::string Fix = NamespaceName + "::";
+    const std::string Fix = NamespaceName + "::";
     Diag << FixItHint::CreateInsertion(NameLoc, Fix);
   }
 
@@ -93,23 +93,21 @@ void ShadowedNamespaceFunctionCheck::check(
       << ShadowedFunc->getDeclName();
 }
 
-void ShadowedNamespaceFunctionCheck::findShadowedInNamespace(
+std::pair<const FunctionDecl *, const NamespaceDecl *> ShadowedNamespaceFunctionCheck::findShadowedInNamespace(
     const NamespaceDecl *NS, 
     const FunctionDecl *GlobalFunc,
-    const std::string &GlobalFuncName,
-    const FunctionDecl *&ShadowedFunc,
-    const NamespaceDecl *&ShadowedNamespace) {
+    const std::string &GlobalFuncName) {
   
   // Skip anonymous namespaces
   if (NS->isAnonymousNamespace())
-    return;
+    return {nullptr, nullptr};
 
   for (const auto *Decl : NS->decls()) {
     // Check nested namespaces
     if (const auto *NestedNS = dyn_cast<NamespaceDecl>(Decl)) {
-      findShadowedInNamespace(NestedNS, GlobalFunc, GlobalFuncName, 
-                             ShadowedFunc, ShadowedNamespace);
-      if (ShadowedFunc) return;
+      auto [ShadowedFunc, ShadowedNamespace] = findShadowedInNamespace(NestedNS, GlobalFunc, GlobalFuncName);
+      if (ShadowedFunc)
+        return {ShadowedFunc, ShadowedNamespace};
     }
 
     // Check functions
@@ -120,12 +118,11 @@ void ShadowedNamespaceFunctionCheck::findShadowedInNamespace(
         continue;
 
       if (Func->getNameAsString() == GlobalFuncName) {
-        ShadowedFunc = Func;
-        ShadowedNamespace = NS;
-        return;
+        return {Func, NS};
       }
     }
   }
+  return {nullptr, nullptr};
 }
 
 } // namespace misc
diff --git a/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.h b/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.h
index 61f4cf8ed1c49..594ab73dc18ab 100644
--- a/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.h
+++ b/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.h
@@ -10,6 +10,7 @@
 #define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MISC_SHADOWEDNAMESPACEFUNCTIONCHECK_H
 
 #include "../ClangTidyCheck.h"
+#include <tuple>
 
 namespace clang::tidy::misc {
 
@@ -27,11 +28,10 @@ class ShadowedNamespaceFunctionCheck : public ClangTidyCheck {
     return LangOpts.CPlusPlus;
   }
 private:
-  void findShadowedInNamespace(const NamespaceDecl *NS,
-                               const FunctionDecl *GlobalFunc,
-                               const std::string &GlobalFuncName,
-                               const FunctionDecl *&ShadowedFunc,
-                               const NamespaceDecl *&ShadowedNamespace);
+  std::pair<const FunctionDecl *, const NamespaceDecl *>
+  findShadowedInNamespace(const NamespaceDecl *NS,
+                          const FunctionDecl *GlobalFunc,
+                          const std::string &GlobalFuncName);
 };
 
 } // namespace clang::tidy::misc

From a2490841477c7c494801617c41818e4c800b1439 Mon Sep 17 00:00:00 2001
From: denzor200 <denismikhaylov38@gmail.com>
Date: Mon, 17 Nov 2025 03:07:56 +0300
Subject: [PATCH 10/19] Fix FP

---
 .../misc/ShadowedNamespaceFunctionCheck.cpp     | 17 +++++++++++++++--
 .../checks/misc/shadowed-namespace-function.rst |  1 +
 .../misc/shadowed-namespace-function-good3.cpp  |  9 +++++++++
 .../misc/shadowed-namespace-function-good4.cpp  |  9 +++++++++
 .../misc/shadowed-namespace-function-using.cpp  | 17 +++++++++++++++++
 .../shadowed-namespace-function-variadic.cpp    |  9 +++++++++
 6 files changed, 60 insertions(+), 2 deletions(-)
 create mode 100644 clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-good3.cpp
 create mode 100644 clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-good4.cpp
 create mode 100644 clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-using.cpp
 create mode 100644 clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-variadic.cpp

diff --git a/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp b/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp
index 669d6793e23cd..9633bf6c3353f 100644
--- a/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp
+++ b/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp
@@ -12,6 +12,7 @@
 #include "clang/ASTMatchers/ASTMatchers.h"
 #include "clang/AST/Decl.h"
 #include "clang/AST/DeclCXX.h"
+#include "llvm/ADT/STLExtras.h"
 
 using namespace clang;
 using namespace clang::ast_matchers;
@@ -21,6 +22,18 @@ namespace clang {
 namespace tidy {
 namespace misc {
 
+static bool hasSameParameters(const FunctionDecl *Func1, const FunctionDecl *Func2) {
+  if (Func1->param_size() != Func2->param_size())
+    return false;
+
+  return llvm::all_of_zip(
+      Func1->parameters(), Func2->parameters(),
+      [](const ParmVarDecl *Param1, const ParmVarDecl *Param2) {
+        return Param1->getType().getCanonicalType() ==
+               Param2->getType().getCanonicalType();
+      });
+}
+
 void ShadowedNamespaceFunctionCheck::registerMatchers(MatchFinder *Finder) {
   // Simple matcher for all function definitions
   Finder->addMatcher(
@@ -45,7 +58,7 @@ void ShadowedNamespaceFunctionCheck::check(
 
   // Skip templates, static functions, main, etc.
   if (Func->isTemplated() || Func->isStatic() || 
-      Func->isMain() || Func->isImplicit())
+      Func->isMain() || Func->isImplicit() || Func->isVariadic())
     return;
 
   const std::string FuncName = Func->getNameAsString();
@@ -117,7 +130,7 @@ std::pair<const FunctionDecl *, const NamespaceDecl *> ShadowedNamespaceFunction
           Func->isThisDeclarationADefinition())
         continue;
 
-      if (Func->getNameAsString() == GlobalFuncName) {
+      if (Func->getNameAsString() == GlobalFuncName && !Func->isVariadic() && hasSameParameters(Func, GlobalFunc) && Func->getReturnType().getCanonicalType() == GlobalFunc->getReturnType().getCanonicalType()) {
         return {Func, NS};
       }
     }
diff --git a/clang-tools-extra/docs/clang-tidy/checks/misc/shadowed-namespace-function.rst b/clang-tools-extra/docs/clang-tidy/checks/misc/shadowed-namespace-function.rst
index b82317fd0a748..04755b21dbd87 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/misc/shadowed-namespace-function.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/misc/shadowed-namespace-function.rst
@@ -42,4 +42,5 @@ Limitations
 - Does not warn about functions in anonymous namespaces
 - Does not warn about template functions
 - Does not warn about static functions or member functions
+- Does not warn about variadic functions
 - Does not warn about the ``main`` function
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-good3.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-good3.cpp
new file mode 100644
index 0000000000000..998f0ff472b69
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-good3.cpp
@@ -0,0 +1,9 @@
+// RUN: %check_clang_tidy %s misc-shadowed-namespace-function %t
+
+void f1(int);
+namespace foo {
+  void f0(short);
+  void f1(unsigned);
+}
+void f0(char) {}
+void f1(int) {}
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-good4.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-good4.cpp
new file mode 100644
index 0000000000000..d6fb377edf586
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-good4.cpp
@@ -0,0 +1,9 @@
+// RUN: %check_clang_tidy %s misc-shadowed-namespace-function %t
+
+int f1();
+namespace foo {
+  char f0();
+  unsigned f1();
+}
+short f0() { return {}; }
+int f1() { return {}; }
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-using.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-using.cpp
new file mode 100644
index 0000000000000..42222e3ba9032
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-using.cpp
@@ -0,0 +1,17 @@
+// RUN: %check_clang_tidy %s misc-shadowed-namespace-function %t
+
+using my_int = int;
+using my_short = short;
+using my_short2 = short;
+
+my_int f1(my_short2);
+namespace foo {
+  int f0(short);
+  int f1(short);
+}
+my_int f0(my_short) {}
+// CHECK-MESSAGES: :[[@LINE-1]]:8: warning: free function 'f0' shadows 'foo::f0' [misc-shadowed-namespace-function]
+// CHECK-FIXES: my_int foo::f0(my_short) {}
+my_int f1(my_short) {}
+// CHECK-MESSAGES: :[[@LINE-1]]:8: warning: free function 'f1' shadows 'foo::f1' [misc-shadowed-namespace-function]
+// CHECK-MESSAGES-NOT: :[[@LINE-2]]:{{.*}}: note: FIX-IT applied suggested code changes
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-variadic.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-variadic.cpp
new file mode 100644
index 0000000000000..794c1cb629df5
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-variadic.cpp
@@ -0,0 +1,9 @@
+// RUN: %check_clang_tidy %s misc-shadowed-namespace-function %t
+
+void f1(...);
+namespace foo {
+  void f0(...);
+  void f1(...);
+}
+void f0(...) {}
+void f1(...) {}

From b1ffd923b596ddf480e9892b0e0f7bd1dd6fa422 Mon Sep 17 00:00:00 2001
From: denzor200 <denismikhaylov38@gmail.com>
Date: Mon, 17 Nov 2025 03:12:34 +0300
Subject: [PATCH 11/19] more unit-tests

---
 .../misc/shadowed-namespace-function-macro.cpp   | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
 create mode 100644 clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-macro.cpp

diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-macro.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-macro.cpp
new file mode 100644
index 0000000000000..540ae9112a21b
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-macro.cpp
@@ -0,0 +1,16 @@
+// RUN: %check_clang_tidy %s misc-shadowed-namespace-function %t
+
+#define VOID_F0 void f0
+#define VOID_F1_BRACES_BODY void f1() {}
+
+void f1();
+namespace foo {
+  void f0();
+  void f1();
+}
+VOID_F0() {}
+// CHECK-MESSAGES: :[[@LINE-1]]:1: warning: free function 'f0' shadows 'foo::f0' [misc-shadowed-namespace-function]
+// CHECK-MESSAGES-NOT: :[[@LINE-2]]:{{.*}}: note: FIX-IT applied suggested code changes
+VOID_F1_BRACES_BODY
+// CHECK-MESSAGES: :[[@LINE-1]]:1: warning: free function 'f1' shadows 'foo::f1' [misc-shadowed-namespace-function]
+// CHECK-MESSAGES-NOT: :[[@LINE-2]]:{{.*}}: note: FIX-IT applied suggested code changes

From 1589ed566dd0a105982f62aeecfca9393aad8f55 Mon Sep 17 00:00:00 2001
From: denzor200 <denismikhaylov38@gmail.com>
Date: Mon, 17 Nov 2025 03:16:31 +0300
Subject: [PATCH 12/19] lint

---
 .../clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp b/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp
index 9633bf6c3353f..ea5f03f342b78 100644
--- a/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp
+++ b/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp
@@ -9,18 +9,16 @@
 #include "ShadowedNamespaceFunctionCheck.h"
 #include "../utils/FixItHintUtils.h"
 #include "clang/AST/ASTContext.h"
-#include "clang/ASTMatchers/ASTMatchers.h"
 #include "clang/AST/Decl.h"
 #include "clang/AST/DeclCXX.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
 #include "llvm/ADT/STLExtras.h"
 
 using namespace clang;
 using namespace clang::ast_matchers;
 using namespace clang::tidy;
 
-namespace clang {
-namespace tidy {
-namespace misc {
+namespace clang::tidy::misc {
 
 static bool hasSameParameters(const FunctionDecl *Func1, const FunctionDecl *Func2) {
   if (Func1->param_size() != Func2->param_size())
@@ -138,7 +136,5 @@ std::pair<const FunctionDecl *, const NamespaceDecl *> ShadowedNamespaceFunction
   return {nullptr, nullptr};
 }
 
-} // namespace misc
-} // namespace tidy
-} // namespace clang
+} // namespace clang::tidy::misc
 

From 3b36a438b1a42e3c76b0e5305dbdc22fc2c5b4d1 Mon Sep 17 00:00:00 2001
From: denzor200 <denismikhaylov38@gmail.com>
Date: Mon, 17 Nov 2025 03:17:09 +0300
Subject: [PATCH 13/19] format

---
 .../misc/ShadowedNamespaceFunctionCheck.cpp   | 54 +++++++++----------
 .../misc/ShadowedNamespaceFunctionCheck.h     |  4 +-
 2 files changed, 30 insertions(+), 28 deletions(-)

diff --git a/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp b/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp
index ea5f03f342b78..0dd9ad0de357f 100644
--- a/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp
+++ b/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp
@@ -20,7 +20,8 @@ using namespace clang::tidy;
 
 namespace clang::tidy::misc {
 
-static bool hasSameParameters(const FunctionDecl *Func1, const FunctionDecl *Func2) {
+static bool hasSameParameters(const FunctionDecl *Func1,
+                              const FunctionDecl *Func2) {
   if (Func1->param_size() != Func2->param_size())
     return false;
 
@@ -34,18 +35,13 @@ static bool hasSameParameters(const FunctionDecl *Func1, const FunctionDecl *Fun
 
 void ShadowedNamespaceFunctionCheck::registerMatchers(MatchFinder *Finder) {
   // Simple matcher for all function definitions
-  Finder->addMatcher(
-      functionDecl(
-          isDefinition()
-      ).bind("func"),
-      this
-  );
+  Finder->addMatcher(functionDecl(isDefinition()).bind("func"), this);
 }
 
 void ShadowedNamespaceFunctionCheck::check(
     const MatchFinder::MatchResult &Result) {
   const auto *Func = Result.Nodes.getNodeAs<FunctionDecl>("func");
-  
+
   if (!Func || !Result.SourceManager)
     return;
 
@@ -55,8 +51,8 @@ void ShadowedNamespaceFunctionCheck::check(
     return;
 
   // Skip templates, static functions, main, etc.
-  if (Func->isTemplated() || Func->isStatic() || 
-      Func->isMain() || Func->isImplicit() || Func->isVariadic())
+  if (Func->isTemplated() || Func->isStatic() || Func->isMain() ||
+      Func->isImplicit() || Func->isVariadic())
     return;
 
   const std::string FuncName = Func->getNameAsString();
@@ -72,8 +68,10 @@ void ShadowedNamespaceFunctionCheck::check(
   // Traverse all declarations in the translation unit
   for (const auto *Decl : Context->getTranslationUnitDecl()->decls()) {
     if (const auto *NS = dyn_cast<NamespaceDecl>(Decl)) {
-      std::tie(ShadowedFunc, ShadowedNamespace) = findShadowedInNamespace(NS, Func, FuncName);
-      if (ShadowedFunc) break;
+      std::tie(ShadowedFunc, ShadowedNamespace) =
+          findShadowedInNamespace(NS, Func, FuncName);
+      if (ShadowedFunc)
+        break;
     }
   }
 
@@ -84,11 +82,10 @@ void ShadowedNamespaceFunctionCheck::check(
     return;
 
   // Generate warning message
-  const std::string NamespaceName = ShadowedNamespace->getQualifiedNameAsString();
-  auto Diag = diag(Func->getLocation(), 
-                   "free function %0 shadows '%1::%2'")
-              << Func->getDeclName() 
-              << NamespaceName 
+  const std::string NamespaceName =
+      ShadowedNamespace->getQualifiedNameAsString();
+  auto Diag = diag(Func->getLocation(), "free function %0 shadows '%1::%2'")
+              << Func->getDeclName() << NamespaceName
               << ShadowedFunc->getDeclName().getAsString();
 
   // Generate fixit hint to add namespace qualification
@@ -99,16 +96,16 @@ void ShadowedNamespaceFunctionCheck::check(
   }
 
   // Note: Also show where the shadowed function is declared
-  diag(ShadowedFunc->getLocation(), 
-       "function %0 declared here", DiagnosticIDs::Note)
+  diag(ShadowedFunc->getLocation(), "function %0 declared here",
+       DiagnosticIDs::Note)
       << ShadowedFunc->getDeclName();
 }
 
-std::pair<const FunctionDecl *, const NamespaceDecl *> ShadowedNamespaceFunctionCheck::findShadowedInNamespace(
-    const NamespaceDecl *NS, 
-    const FunctionDecl *GlobalFunc,
+std::pair<const FunctionDecl *, const NamespaceDecl *>
+ShadowedNamespaceFunctionCheck::findShadowedInNamespace(
+    const NamespaceDecl *NS, const FunctionDecl *GlobalFunc,
     const std::string &GlobalFuncName) {
-  
+
   // Skip anonymous namespaces
   if (NS->isAnonymousNamespace())
     return {nullptr, nullptr};
@@ -116,7 +113,8 @@ std::pair<const FunctionDecl *, const NamespaceDecl *> ShadowedNamespaceFunction
   for (const auto *Decl : NS->decls()) {
     // Check nested namespaces
     if (const auto *NestedNS = dyn_cast<NamespaceDecl>(Decl)) {
-      auto [ShadowedFunc, ShadowedNamespace] = findShadowedInNamespace(NestedNS, GlobalFunc, GlobalFuncName);
+      auto [ShadowedFunc, ShadowedNamespace] =
+          findShadowedInNamespace(NestedNS, GlobalFunc, GlobalFuncName);
       if (ShadowedFunc)
         return {ShadowedFunc, ShadowedNamespace};
     }
@@ -124,11 +122,14 @@ std::pair<const FunctionDecl *, const NamespaceDecl *> ShadowedNamespaceFunction
     // Check functions
     if (const auto *Func = dyn_cast<FunctionDecl>(Decl)) {
       // Skip if it's the same function, templates, or definitions
-      if (Func == GlobalFunc || Func->isTemplated() || 
+      if (Func == GlobalFunc || Func->isTemplated() ||
           Func->isThisDeclarationADefinition())
         continue;
 
-      if (Func->getNameAsString() == GlobalFuncName && !Func->isVariadic() && hasSameParameters(Func, GlobalFunc) && Func->getReturnType().getCanonicalType() == GlobalFunc->getReturnType().getCanonicalType()) {
+      if (Func->getNameAsString() == GlobalFuncName && !Func->isVariadic() &&
+          hasSameParameters(Func, GlobalFunc) &&
+          Func->getReturnType().getCanonicalType() ==
+              GlobalFunc->getReturnType().getCanonicalType()) {
         return {Func, NS};
       }
     }
@@ -137,4 +138,3 @@ std::pair<const FunctionDecl *, const NamespaceDecl *> ShadowedNamespaceFunction
 }
 
 } // namespace clang::tidy::misc
-
diff --git a/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.h b/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.h
index 594ab73dc18ab..8ee09272fffed 100644
--- a/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.h
+++ b/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.h
@@ -14,7 +14,8 @@
 
 namespace clang::tidy::misc {
 
-/// Detects free functions in global namespace that shadow functions from other namespaces.
+/// Detects free functions in global namespace that shadow functions from other
+/// namespaces.
 ///
 /// For the user-facing documentation see:
 /// https://clang.llvm.org/extra/clang-tidy/checks/misc/shadowed-namespace-function.html
@@ -27,6 +28,7 @@ class ShadowedNamespaceFunctionCheck : public ClangTidyCheck {
   bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {
     return LangOpts.CPlusPlus;
   }
+
 private:
   std::pair<const FunctionDecl *, const NamespaceDecl *>
   findShadowedInNamespace(const NamespaceDecl *NS,

From 1f7748d4eb7146bee27e16f1258d71d000e79a59 Mon Sep 17 00:00:00 2001
From: denzor200 <denismikhaylov38@gmail.com>
Date: Mon, 17 Nov 2025 19:13:43 +0300
Subject: [PATCH 14/19] friend

---
 .../misc/shadowed-namespace-function.rst      | 30 ++++++++++++++-----
 .../shadowed-namespace-function-friend.cpp    | 16 ++++++++++
 2 files changed, 39 insertions(+), 7 deletions(-)
 create mode 100644 clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-friend.cpp

diff --git a/clang-tools-extra/docs/clang-tidy/checks/misc/shadowed-namespace-function.rst b/clang-tools-extra/docs/clang-tidy/checks/misc/shadowed-namespace-function.rst
index 04755b21dbd87..c14251000d29c 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/misc/shadowed-namespace-function.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/misc/shadowed-namespace-function.rst
@@ -31,16 +31,32 @@ The check will suggest adding the appropriate namespace qualification:
   - void process() {}
   + void utils::process() {}
 
-Options
--------
-
-None
+The check will not warn about:
+- Static functions or member functions;
+- Functions in anonymous namespaces;
+- The ``main`` function.
 
 Limitations
 -----------
 
-- Does not warn about functions in anonymous namespaces
+- Does not warn about friend functions:
+
+.. code-block:: c++
+
+  namespace llvm::gsym {
+    struct MergedFunctionsInfo {
+        friend bool operator==(const llvm::gsym::MergedFunctionsInfo &LHS,
+                               const llvm::gsym::MergedFunctionsInfo &RHS);
+    };
+  }
+
+  using namespace llvm::gsym;
+
+  bool operator==(const MergedFunctionsInfo &LHS,  // no warning in this version
+                  const MergedFunctionsInfo &RHS) {
+    return LHS.MergedFunctions == RHS.MergedFunctions;
+  }
+
 - Does not warn about template functions
-- Does not warn about static functions or member functions
 - Does not warn about variadic functions
-- Does not warn about the ``main`` function
+
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-friend.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-friend.cpp
new file mode 100644
index 0000000000000..f70474987922d
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-friend.cpp
@@ -0,0 +1,16 @@
+// RUN: %check_clang_tidy %s misc-shadowed-namespace-function %t
+
+
+namespace foo { struct A; }
+void f1(foo::A);
+
+namespace foo {
+  struct A{
+    friend void f0(A);
+    friend void f1(A);
+  };
+}
+
+// FIXME: provide warning without fixit in these two cases
+void f0(foo::A) {}
+void f1(foo::A) {}

From d6bdb398bde17319da8b7455c96b6709319f41f3 Mon Sep 17 00:00:00 2001
From: denzor200 <denismikhaylov38@gmail.com>
Date: Mon, 17 Nov 2025 19:16:45 +0300
Subject: [PATCH 15/19] fix doc

---
 .../clang-tidy/checks/misc/shadowed-namespace-function.rst   | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/clang-tools-extra/docs/clang-tidy/checks/misc/shadowed-namespace-function.rst b/clang-tools-extra/docs/clang-tidy/checks/misc/shadowed-namespace-function.rst
index c14251000d29c..628a6ef190430 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/misc/shadowed-namespace-function.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/misc/shadowed-namespace-function.rst
@@ -32,6 +32,7 @@ The check will suggest adding the appropriate namespace qualification:
   + void utils::process() {}
 
 The check will not warn about:
+
 - Static functions or member functions;
 - Functions in anonymous namespaces;
 - The ``main`` function.
@@ -45,8 +46,8 @@ Limitations
 
   namespace llvm::gsym {
     struct MergedFunctionsInfo {
-        friend bool operator==(const llvm::gsym::MergedFunctionsInfo &LHS,
-                               const llvm::gsym::MergedFunctionsInfo &RHS);
+        friend bool operator==(const MergedFunctionsInfo &LHS,
+                               const MergedFunctionsInfo &RHS);
     };
   }
 

From 51eac24d050f6b26f3b963584ca260ec77e6e7fc Mon Sep 17 00:00:00 2001
From: denzor200 <denismikhaylov38@gmail.com>
Date: Mon, 17 Nov 2025 19:22:47 +0300
Subject: [PATCH 16/19] important TODOs for future versions of check

---
 .../checkers/misc/shadowed-namespace-function-template.cpp     | 3 +++
 .../checkers/misc/shadowed-namespace-function-variadic.cpp     | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-template.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-template.cpp
index 48924fcdb932d..ad99e524b0207 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-template.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-template.cpp
@@ -8,6 +8,9 @@ namespace foo {
   template<typename T>
   void f1();
 }
+
+// FIXME: provide warning in these two cases
+// FIXME: provide fixit for f0
 template<typename T>
 void f0() {}
 template<typename T>
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-variadic.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-variadic.cpp
index 794c1cb629df5..cd470d28551c3 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-variadic.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-variadic.cpp
@@ -5,5 +5,8 @@ namespace foo {
   void f0(...);
   void f1(...);
 }
+
+// FIXME: warning in these two cases??
+// FIXME: fixit for f0??
 void f0(...) {}
 void f1(...) {}

From 532b761e793b957b019eb46d87a7ee5748232045 Mon Sep 17 00:00:00 2001
From: denzor200 <denismikhaylov38@gmail.com>
Date: Tue, 18 Nov 2025 01:18:44 +0300
Subject: [PATCH 17/19] refactor tests

---
 ...namespace-function-anonymous-namespace.cpp |  11 --
 .../shadowed-namespace-function-friend.cpp    |  16 --
 .../misc/shadowed-namespace-function-good.cpp |   9 -
 .../shadowed-namespace-function-good2.cpp     |  11 --
 .../shadowed-namespace-function-good3.cpp     |   9 -
 .../shadowed-namespace-function-good4.cpp     |   9 -
 .../shadowed-namespace-function-macro.cpp     |  16 --
 .../misc/shadowed-namespace-function-main.cpp |   6 -
 .../shadowed-namespace-function-nested.cpp    |  13 --
 .../shadowed-namespace-function-static.cpp    |   9 -
 .../shadowed-namespace-function-template.cpp  |  17 --
 .../shadowed-namespace-function-using.cpp     |  17 --
 .../shadowed-namespace-function-variadic.cpp  |  12 --
 .../misc/shadowed-namespace-function.cpp      | 185 +++++++++++++++++-
 14 files changed, 177 insertions(+), 163 deletions(-)
 delete mode 100644 clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-anonymous-namespace.cpp
 delete mode 100644 clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-friend.cpp
 delete mode 100644 clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-good.cpp
 delete mode 100644 clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-good2.cpp
 delete mode 100644 clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-good3.cpp
 delete mode 100644 clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-good4.cpp
 delete mode 100644 clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-macro.cpp
 delete mode 100644 clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-main.cpp
 delete mode 100644 clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-nested.cpp
 delete mode 100644 clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-static.cpp
 delete mode 100644 clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-template.cpp
 delete mode 100644 clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-using.cpp
 delete mode 100644 clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-variadic.cpp

diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-anonymous-namespace.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-anonymous-namespace.cpp
deleted file mode 100644
index 1689843464ae1..0000000000000
--- a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-anonymous-namespace.cpp
+++ /dev/null
@@ -1,11 +0,0 @@
-// RUN: %check_clang_tidy %s misc-shadowed-namespace-function %t
-
-namespace { void f1(); }
-namespace foo {
-  void f0();
-  void f1();
-}
-namespace {
-void f0() {}
-void f1() {}
-}
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-friend.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-friend.cpp
deleted file mode 100644
index f70474987922d..0000000000000
--- a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-friend.cpp
+++ /dev/null
@@ -1,16 +0,0 @@
-// RUN: %check_clang_tidy %s misc-shadowed-namespace-function %t
-
-
-namespace foo { struct A; }
-void f1(foo::A);
-
-namespace foo {
-  struct A{
-    friend void f0(A);
-    friend void f1(A);
-  };
-}
-
-// FIXME: provide warning without fixit in these two cases
-void f0(foo::A) {}
-void f1(foo::A) {}
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-good.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-good.cpp
deleted file mode 100644
index 17abae5e943b6..0000000000000
--- a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-good.cpp
+++ /dev/null
@@ -1,9 +0,0 @@
-// RUN: %check_clang_tidy %s misc-shadowed-namespace-function %t
-
-void f1();
-namespace foo {
-  void f0() {}
-  void f1() {}
-}
-void f0() {}
-void f1() {}
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-good2.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-good2.cpp
deleted file mode 100644
index b3218afa60e9d..0000000000000
--- a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-good2.cpp
+++ /dev/null
@@ -1,11 +0,0 @@
-// RUN: %check_clang_tidy %s misc-shadowed-namespace-function %t
-
-void f1();
-namespace foo {
-  void f0();
-  void f1();
-}
-void foo::f0() {}
-void foo::f1() {}
-void f0() {}
-void f1() {}
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-good3.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-good3.cpp
deleted file mode 100644
index 998f0ff472b69..0000000000000
--- a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-good3.cpp
+++ /dev/null
@@ -1,9 +0,0 @@
-// RUN: %check_clang_tidy %s misc-shadowed-namespace-function %t
-
-void f1(int);
-namespace foo {
-  void f0(short);
-  void f1(unsigned);
-}
-void f0(char) {}
-void f1(int) {}
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-good4.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-good4.cpp
deleted file mode 100644
index d6fb377edf586..0000000000000
--- a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-good4.cpp
+++ /dev/null
@@ -1,9 +0,0 @@
-// RUN: %check_clang_tidy %s misc-shadowed-namespace-function %t
-
-int f1();
-namespace foo {
-  char f0();
-  unsigned f1();
-}
-short f0() { return {}; }
-int f1() { return {}; }
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-macro.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-macro.cpp
deleted file mode 100644
index 540ae9112a21b..0000000000000
--- a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-macro.cpp
+++ /dev/null
@@ -1,16 +0,0 @@
-// RUN: %check_clang_tidy %s misc-shadowed-namespace-function %t
-
-#define VOID_F0 void f0
-#define VOID_F1_BRACES_BODY void f1() {}
-
-void f1();
-namespace foo {
-  void f0();
-  void f1();
-}
-VOID_F0() {}
-// CHECK-MESSAGES: :[[@LINE-1]]:1: warning: free function 'f0' shadows 'foo::f0' [misc-shadowed-namespace-function]
-// CHECK-MESSAGES-NOT: :[[@LINE-2]]:{{.*}}: note: FIX-IT applied suggested code changes
-VOID_F1_BRACES_BODY
-// CHECK-MESSAGES: :[[@LINE-1]]:1: warning: free function 'f1' shadows 'foo::f1' [misc-shadowed-namespace-function]
-// CHECK-MESSAGES-NOT: :[[@LINE-2]]:{{.*}}: note: FIX-IT applied suggested code changes
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-main.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-main.cpp
deleted file mode 100644
index 4321486ba7101..0000000000000
--- a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-main.cpp
+++ /dev/null
@@ -1,6 +0,0 @@
-// RUN: %check_clang_tidy %s misc-shadowed-namespace-function %t
-
-namespace foo {
-  int main();
-}
-int main() {}
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-nested.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-nested.cpp
deleted file mode 100644
index 41b130624bbaa..0000000000000
--- a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-nested.cpp
+++ /dev/null
@@ -1,13 +0,0 @@
-// RUN: %check_clang_tidy %s misc-shadowed-namespace-function %t
-
-void f1();
-namespace foo::foo2::foo3 {
-  void f0();
-  void f1();
-}
-void f0() {}
-// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: free function 'f0' shadows 'foo::foo2::foo3::f0' [misc-shadowed-namespace-function]
-// CHECK-FIXES: void foo::foo2::foo3::f0() {}
-void f1() {}
-// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: free function 'f1' shadows 'foo::foo2::foo3::f1' [misc-shadowed-namespace-function]
-// CHECK-MESSAGES-NOT: :[[@LINE-2]]:{{.*}}: note: FIX-IT applied suggested code changes
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-static.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-static.cpp
deleted file mode 100644
index d1371c044d112..0000000000000
--- a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-static.cpp
+++ /dev/null
@@ -1,9 +0,0 @@
-// RUN: %check_clang_tidy %s misc-shadowed-namespace-function %t
-
-static void f1();
-namespace foo {
-  void f0();
-  void f1();
-}
-static void f0() {}
-static void f1() {}
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-template.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-template.cpp
deleted file mode 100644
index ad99e524b0207..0000000000000
--- a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-template.cpp
+++ /dev/null
@@ -1,17 +0,0 @@
-// RUN: %check_clang_tidy %s misc-shadowed-namespace-function %t
-
-template<typename T>
-void f1();
-namespace foo {
-  template<typename T>
-  void f0();
-  template<typename T>
-  void f1();
-}
-
-// FIXME: provide warning in these two cases
-// FIXME: provide fixit for f0
-template<typename T>
-void f0() {}
-template<typename T>
-void f1() {}
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-using.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-using.cpp
deleted file mode 100644
index 42222e3ba9032..0000000000000
--- a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-using.cpp
+++ /dev/null
@@ -1,17 +0,0 @@
-// RUN: %check_clang_tidy %s misc-shadowed-namespace-function %t
-
-using my_int = int;
-using my_short = short;
-using my_short2 = short;
-
-my_int f1(my_short2);
-namespace foo {
-  int f0(short);
-  int f1(short);
-}
-my_int f0(my_short) {}
-// CHECK-MESSAGES: :[[@LINE-1]]:8: warning: free function 'f0' shadows 'foo::f0' [misc-shadowed-namespace-function]
-// CHECK-FIXES: my_int foo::f0(my_short) {}
-my_int f1(my_short) {}
-// CHECK-MESSAGES: :[[@LINE-1]]:8: warning: free function 'f1' shadows 'foo::f1' [misc-shadowed-namespace-function]
-// CHECK-MESSAGES-NOT: :[[@LINE-2]]:{{.*}}: note: FIX-IT applied suggested code changes
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-variadic.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-variadic.cpp
deleted file mode 100644
index cd470d28551c3..0000000000000
--- a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function-variadic.cpp
+++ /dev/null
@@ -1,12 +0,0 @@
-// RUN: %check_clang_tidy %s misc-shadowed-namespace-function %t
-
-void f1(...);
-namespace foo {
-  void f0(...);
-  void f1(...);
-}
-
-// FIXME: warning in these two cases??
-// FIXME: fixit for f0??
-void f0(...) {}
-void f1(...) {}
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function.cpp
index 920556cca0381..28e2f0c56df54 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/misc/shadowed-namespace-function.cpp
@@ -1,13 +1,182 @@
 // RUN: %check_clang_tidy %s misc-shadowed-namespace-function %t
 
-void f1();
+void f1_general();
+namespace foo_general {
+  void f0_general();
+  void f1_general();
+}
+void f0_general() {}
+// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: free function 'f0_general' shadows 'foo_general::f0_general' [misc-shadowed-namespace-function]
+// CHECK-FIXES: void foo_general::f0_general() {}
+void f1_general() {}
+// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: free function 'f1_general' shadows 'foo_general::f1_general' [misc-shadowed-namespace-function]
+// CHECK-MESSAGES-NOT: :[[@LINE-2]]:{{.*}}: note: FIX-IT applied suggested code changes
+
+//////////////////////////////////////////////////////////////////////////////////////////
+
+void f1_variadic(...);
+namespace foo_variadic {
+  void f0_variadic(...);
+  void f1_variadic(...);
+}
+
+// FIXME: warning in these two cases??
+// FIXME: fixit for f0??
+void f0_variadic(...) {}
+void f1_variadic(...) {}
+
+//////////////////////////////////////////////////////////////////////////////////////////
+
+using my_int = int;
+using my_short = short;
+using my_short2 = short;
+
+my_int f1_using(my_short2);
+namespace foo_using {
+  int f0_using(short);
+  int f1_using(short);
+}
+my_int f0_using(my_short) {}
+// CHECK-MESSAGES: :[[@LINE-1]]:8: warning: free function 'f0_using' shadows 'foo_using::f0_using' [misc-shadowed-namespace-function]
+// CHECK-FIXES: my_int foo_using::f0_using(my_short) {}
+my_int f1_using(my_short) {}
+// CHECK-MESSAGES: :[[@LINE-1]]:8: warning: free function 'f1_using' shadows 'foo_using::f1_using' [misc-shadowed-namespace-function]
+// CHECK-MESSAGES-NOT: :[[@LINE-2]]:{{.*}}: note: FIX-IT applied suggested code changes
+
+//////////////////////////////////////////////////////////////////////////////////////////
+
+template<typename T>
+void f1_template();
 namespace foo {
-  void f0();
-  void f1();
+  template<typename T>
+  void f0_template();
+  template<typename T>
+  void f1_template();
 }
-void f0() {}
-// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: free function 'f0' shadows 'foo::f0' [misc-shadowed-namespace-function]
-// CHECK-FIXES: void foo::f0() {}
-void f1() {}
-// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: free function 'f1' shadows 'foo::f1' [misc-shadowed-namespace-function]
+
+// FIXME: provide warning in these two cases
+// FIXME: provide fixit for f0
+template<typename T>
+void f0_template() {}
+template<typename T>
+void f1_template() {}
+
+//////////////////////////////////////////////////////////////////////////////////////////
+
+static void f1_static();
+namespace foo_static {
+  void f0_static();
+  void f1_static();
+}
+static void f0_static() {}
+static void f1_static() {}
+
+//////////////////////////////////////////////////////////////////////////////////////////
+
+void f1_nested();
+namespace foo_nested::foo2::foo3 {
+  void f0_nested();
+  void f1_nested();
+}
+void f0_nested() {}
+// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: free function 'f0_nested' shadows 'foo_nested::foo2::foo3::f0_nested' [misc-shadowed-namespace-function]
+// CHECK-FIXES: void foo_nested::foo2::foo3::f0_nested() {}
+void f1_nested() {}
+// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: free function 'f1_nested' shadows 'foo_nested::foo2::foo3::f1_nested' [misc-shadowed-namespace-function]
 // CHECK-MESSAGES-NOT: :[[@LINE-2]]:{{.*}}: note: FIX-IT applied suggested code changes
+
+//////////////////////////////////////////////////////////////////////////////////////////
+
+namespace foo_main {
+  int main();
+}
+int main() {}
+
+//////////////////////////////////////////////////////////////////////////////////////////
+
+#define VOID_F0 void f0_macro
+#define VOID_F1_BRACES_BODY void f1_macro() {}
+
+void f1_macro();
+namespace foo_macro {
+  void f0_macro();
+  void f1_macro();
+}
+VOID_F0() {}
+// CHECK-MESSAGES: :[[@LINE-1]]:1: warning: free function 'f0_macro' shadows 'foo_macro::f0_macro' [misc-shadowed-namespace-function]
+// CHECK-MESSAGES-NOT: :[[@LINE-2]]:{{.*}}: note: FIX-IT applied suggested code changes
+VOID_F1_BRACES_BODY
+// CHECK-MESSAGES: :[[@LINE-1]]:1: warning: free function 'f1_macro' shadows 'foo_macro::f1_macro' [misc-shadowed-namespace-function]
+// CHECK-MESSAGES-NOT: :[[@LINE-2]]:{{.*}}: note: FIX-IT applied suggested code changes
+
+//////////////////////////////////////////////////////////////////////////////////////////
+
+void f1_good();
+namespace foo_good {
+  void f0_good() {}
+  void f1_good() {}
+}
+void f0_good() {}
+void f1_good() {}
+
+//////////////////////////////////////////////////////////////////////////////////////////
+
+void f1_good2();
+namespace foo_good2 {
+  void f0_good2();
+  void f1_good2();
+}
+void foo_good2::f0_good2() {}
+void foo_good2::f1_good2() {}
+void f0_good2() {}
+void f1_good2() {}
+
+//////////////////////////////////////////////////////////////////////////////////////////
+
+void f1_good3(int);
+namespace foo_good3 {
+  void f0_good3(short);
+  void f1_good3(unsigned);
+}
+void f0_good3(char) {}
+void f1_good3(int) {}
+
+//////////////////////////////////////////////////////////////////////////////////////////
+
+int f1_good4();
+namespace foo_good4 {
+  char f0_good4();
+  unsigned f1_good4();
+}
+short f0_good4() { return {}; }
+int f1_good4() { return {}; }
+
+//////////////////////////////////////////////////////////////////////////////////////////
+
+namespace foo_friend { struct A; }
+void f1_friend(foo_friend::A);
+
+namespace foo_friend {
+  struct A{
+    friend void f0_friend(A);
+    friend void f1_friend(A);
+  };
+}
+
+// FIXME: provide warning without fixit in these two cases
+void f0_friend(foo_friend::A) {}
+void f1_friend(foo_friend::A) {}
+
+//////////////////////////////////////////////////////////////////////////////////////////
+
+namespace { void f1_anon(); }
+namespace foo_anon {
+  void f0_anon();
+  void f1_anon();
+}
+namespace {
+void f0_anon() {}
+void f1_anon() {}
+}
+
+//////////////////////////////////////////////////////////////////////////////////////////

From 94ebafa18f82090d843e5998daeab339ca52fd1b Mon Sep 17 00:00:00 2001
From: denzor200 <denismikhaylov38@gmail.com>
Date: Tue, 18 Nov 2025 15:34:30 +0300
Subject: [PATCH 18/19] review

---
 .../misc/ShadowedNamespaceFunctionCheck.cpp   | 94 ++++++++-----------
 .../misc/ShadowedNamespaceFunctionCheck.h     |  6 --
 clang-tools-extra/docs/ReleaseNotes.rst       |  3 +-
 .../misc/shadowed-namespace-function.rst      | 11 ++-
 4 files changed, 46 insertions(+), 68 deletions(-)

diff --git a/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp b/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp
index 0dd9ad0de357f..f7e6f3be5ae5b 100644
--- a/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp
+++ b/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp
@@ -33,39 +33,60 @@ static bool hasSameParameters(const FunctionDecl *Func1,
       });
 }
 
+static
+std::pair<const FunctionDecl *, const NamespaceDecl *>
+findShadowedInNamespace(
+    const NamespaceDecl *NS, const FunctionDecl *GlobalFunc,
+    const std::string &GlobalFuncName) {
+
+  if (NS->isAnonymousNamespace())
+    return {nullptr, nullptr};
+
+  for (const auto *Decl : NS->decls()) {
+    // Check nested namespaces
+    if (const auto *NestedNS = dyn_cast<NamespaceDecl>(Decl)) {
+      auto [ShadowedFunc, ShadowedNamespace] =
+          findShadowedInNamespace(NestedNS, GlobalFunc, GlobalFuncName);
+      if (ShadowedFunc)
+        return {ShadowedFunc, ShadowedNamespace};
+    }
+
+    // Check functions
+    if (const auto *Func = dyn_cast<FunctionDecl>(Decl)) {
+      if (Func == GlobalFunc || Func->isTemplated() ||
+          Func->isThisDeclarationADefinition())
+        continue;
+
+      if (Func->getNameAsString() == GlobalFuncName && !Func->isVariadic() &&
+          hasSameParameters(Func, GlobalFunc) &&
+          Func->getReturnType().getCanonicalType() ==
+              GlobalFunc->getReturnType().getCanonicalType()) {
+        return {Func, NS};
+      }
+    }
+  }
+  return {nullptr, nullptr};
+}
+
 void ShadowedNamespaceFunctionCheck::registerMatchers(MatchFinder *Finder) {
-  // Simple matcher for all function definitions
-  Finder->addMatcher(functionDecl(isDefinition()).bind("func"), this);
+  Finder->addMatcher(functionDecl(isDefinition(), decl(hasDeclContext(translationUnitDecl())), unless(
+    anyOf(isImplicit(), isVariadic(), isMain(), isStaticStorageClass(), ast_matchers::isTemplateInstantiation())
+  )).bind("func"), this);
 }
 
 void ShadowedNamespaceFunctionCheck::check(
     const MatchFinder::MatchResult &Result) {
   const auto *Func = Result.Nodes.getNodeAs<FunctionDecl>("func");
 
-  if (!Func || !Result.SourceManager)
-    return;
-
-  // Skip if not in global namespace
-  const DeclContext *DC = Func->getDeclContext();
-  if (!DC->isTranslationUnit())
-    return;
-
-  // Skip templates, static functions, main, etc.
-  if (Func->isTemplated() || Func->isStatic() || Func->isMain() ||
-      Func->isImplicit() || Func->isVariadic())
-    return;
-
   const std::string FuncName = Func->getNameAsString();
   if (FuncName.empty())
     return;
 
   const ASTContext *Context = Result.Context;
 
-  // Look for functions with the same name in namespaces
   const FunctionDecl *ShadowedFunc = nullptr;
   const NamespaceDecl *ShadowedNamespace = nullptr;
 
-  // Traverse all declarations in the translation unit
   for (const auto *Decl : Context->getTranslationUnitDecl()->decls()) {
     if (const auto *NS = dyn_cast<NamespaceDecl>(Decl)) {
       std::tie(ShadowedFunc, ShadowedNamespace) =
@@ -81,60 +102,21 @@ void ShadowedNamespaceFunctionCheck::check(
   if (ShadowedFunc->getDefinition())
     return;
 
-  // Generate warning message
   const std::string NamespaceName =
       ShadowedNamespace->getQualifiedNameAsString();
   auto Diag = diag(Func->getLocation(), "free function %0 shadows '%1::%2'")
               << Func->getDeclName() << NamespaceName
               << ShadowedFunc->getDeclName().getAsString();
 
-  // Generate fixit hint to add namespace qualification
   const SourceLocation NameLoc = Func->getLocation();
   if (NameLoc.isValid() && !Func->getPreviousDecl()) {
     const std::string Fix = NamespaceName + "::";
     Diag << FixItHint::CreateInsertion(NameLoc, Fix);
   }
 
-  // Note: Also show where the shadowed function is declared
   diag(ShadowedFunc->getLocation(), "function %0 declared here",
        DiagnosticIDs::Note)
       << ShadowedFunc->getDeclName();
 }
 
-std::pair<const FunctionDecl *, const NamespaceDecl *>
-ShadowedNamespaceFunctionCheck::findShadowedInNamespace(
-    const NamespaceDecl *NS, const FunctionDecl *GlobalFunc,
-    const std::string &GlobalFuncName) {
-
-  // Skip anonymous namespaces
-  if (NS->isAnonymousNamespace())
-    return {nullptr, nullptr};
-
-  for (const auto *Decl : NS->decls()) {
-    // Check nested namespaces
-    if (const auto *NestedNS = dyn_cast<NamespaceDecl>(Decl)) {
-      auto [ShadowedFunc, ShadowedNamespace] =
-          findShadowedInNamespace(NestedNS, GlobalFunc, GlobalFuncName);
-      if (ShadowedFunc)
-        return {ShadowedFunc, ShadowedNamespace};
-    }
-
-    // Check functions
-    if (const auto *Func = dyn_cast<FunctionDecl>(Decl)) {
-      // Skip if it's the same function, templates, or definitions
-      if (Func == GlobalFunc || Func->isTemplated() ||
-          Func->isThisDeclarationADefinition())
-        continue;
-
-      if (Func->getNameAsString() == GlobalFuncName && !Func->isVariadic() &&
-          hasSameParameters(Func, GlobalFunc) &&
-          Func->getReturnType().getCanonicalType() ==
-              GlobalFunc->getReturnType().getCanonicalType()) {
-        return {Func, NS};
-      }
-    }
-  }
-  return {nullptr, nullptr};
-}
-
 } // namespace clang::tidy::misc
diff --git a/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.h b/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.h
index 8ee09272fffed..93dc69f157281 100644
--- a/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.h
+++ b/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.h
@@ -28,12 +28,6 @@ class ShadowedNamespaceFunctionCheck : public ClangTidyCheck {
   bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {
     return LangOpts.CPlusPlus;
   }
-
-private:
-  std::pair<const FunctionDecl *, const NamespaceDecl *>
-  findShadowedInNamespace(const NamespaceDecl *NS,
-                          const FunctionDecl *GlobalFunc,
-                          const std::string &GlobalFuncName);
 };
 
 } // namespace clang::tidy::misc
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index a1482d89b6042..42772b5335dd1 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -229,7 +229,8 @@ New checks
 - New :doc:`misc-shadowed-namespace-function
   <clang-tidy/checks/misc/shadowed-namespace-function>` check.
 
-  Detects free functions in global namespace that shadow functions from other namespaces.
+  Detects free functions in global namespace that shadow functions from other
+  namespaces.
 
 - New :doc:`readability-redundant-parentheses
   <clang-tidy/checks/readability/redundant-parentheses>` check.
diff --git a/clang-tools-extra/docs/clang-tidy/checks/misc/shadowed-namespace-function.rst b/clang-tools-extra/docs/clang-tidy/checks/misc/shadowed-namespace-function.rst
index 628a6ef190430..5dc8930dde782 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/misc/shadowed-namespace-function.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/misc/shadowed-namespace-function.rst
@@ -4,9 +4,11 @@ misc-shadowed-namespace-function
 ================================
 
 Detects free functions in the global namespace that shadow functions declared 
-in other namespaces. This check helps prevent accidental shadowing of namespace
-functions, which can lead to confusion about which function is being called and
-potential linking errors.
+in other namespaces.
+
+This check helps prevent accidental shadowing of namespace functions, which can
+lead to confusion about which function is being called and potential linking
+errors.
 
 Examples
 --------
@@ -59,5 +61,4 @@ Limitations
   }
 
 - Does not warn about template functions
-- Does not warn about variadic functions
-
+- Does not warn about variadic functions.

From cd94fa73e75e886a98f4b3b33ddcf9de1d8bd54e Mon Sep 17 00:00:00 2001
From: denzor200 <denismikhaylov38@gmail.com>
Date: Tue, 18 Nov 2025 15:41:42 +0300
Subject: [PATCH 19/19] format

---
 .../misc/ShadowedNamespaceFunctionCheck.cpp    | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp b/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp
index f7e6f3be5ae5b..b1865ca459088 100644
--- a/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp
+++ b/clang-tools-extra/clang-tidy/misc/ShadowedNamespaceFunctionCheck.cpp
@@ -33,11 +33,9 @@ static bool hasSameParameters(const FunctionDecl *Func1,
       });
 }
 
-static
-std::pair<const FunctionDecl *, const NamespaceDecl *>
-findShadowedInNamespace(
-    const NamespaceDecl *NS, const FunctionDecl *GlobalFunc,
-    const std::string &GlobalFuncName) {
+static std::pair<const FunctionDecl *, const NamespaceDecl *>
+findShadowedInNamespace(const NamespaceDecl *NS, const FunctionDecl *GlobalFunc,
+                        const std::string &GlobalFuncName) {
 
   if (NS->isAnonymousNamespace())
     return {nullptr, nullptr};
@@ -69,9 +67,13 @@ findShadowedInNamespace(
 }
 
 void ShadowedNamespaceFunctionCheck::registerMatchers(MatchFinder *Finder) {
-  Finder->addMatcher(functionDecl(isDefinition(), decl(hasDeclContext(translationUnitDecl())), unless(
-    anyOf(isImplicit(), isVariadic(), isMain(), isStaticStorageClass(), ast_matchers::isTemplateInstantiation())
-  )).bind("func"), this);
+  Finder->addMatcher(
+      functionDecl(isDefinition(), decl(hasDeclContext(translationUnitDecl())),
+                   unless(anyOf(isImplicit(), isVariadic(), isMain(),
+                                isStaticStorageClass(),
+                                ast_matchers::isTemplateInstantiation())))
+          .bind("func"),
+      this);
 }
 
 void ShadowedNamespaceFunctionCheck::check(