[clang-tools-extra] [clang-tidy] Overloaded Unresolved member function call can't be static (PR #191432)

[Gaurav Dhingra via cfe-commits]

https://github.com/gxyd updated https://github.com/llvm/llvm-project/pull/191432

>From 504f90764c855abbc01a07bdbc98406893d57c5b Mon Sep 17 00:00:00 2001
From: Gaurav Dhingra <gauravdhingra.gxyd at gmail.com>
Date: Fri, 10 Apr 2026 19:55:21 +0530
Subject: [PATCH 1/3] [clang-tidy] Unresolve member function call can't be
 static

readability-convert-member-functions-to-static incorrectly suggests
making overloaded member function, with lambda function call, as
static (false-positive)

Mark usage of "this" as true, when a call to "UnresolveMemberExpr"
is obvserved

Fixes #171626
---
 .../readability/ConvertMemberFunctionsToStaticCheck.cpp      | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/clang-tools-extra/clang-tidy/readability/ConvertMemberFunctionsToStaticCheck.cpp b/clang-tools-extra/clang-tidy/readability/ConvertMemberFunctionsToStaticCheck.cpp
index 4bca9686e94e1..366f078d8f2ec 100644
--- a/clang-tools-extra/clang-tidy/readability/ConvertMemberFunctionsToStaticCheck.cpp
+++ b/clang-tools-extra/clang-tidy/readability/ConvertMemberFunctionsToStaticCheck.cpp
@@ -64,6 +64,11 @@ AST_MATCHER(CXXMethodDecl, usesThis) {
       return false; // Stop traversal.
     }
 
+    bool VisitUnresolvedMemberExpr(const UnresolvedMemberExpr *E) {
+      Used = true;
+      return false;
+    }
+
     // If we enter a class declaration, don't traverse into it as any usages of
     // `this` will correspond to the nested class.
     bool TraverseCXXRecordDecl(CXXRecordDecl *RD) { return true; }

>From 58b8421c62ad76a7d46cac162d875f57c32a36c0 Mon Sep 17 00:00:00 2001
From: Gaurav Dhingra <gauravdhingra.gxyd at gmail.com>
Date: Fri, 10 Apr 2026 20:07:06 +0530
Subject: [PATCH 2/3] add tests for overloaded unresolve with lambda call

---
 ...mber-functions-to-static-deducing-this.cpp | 24 +++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/clang-tools-extra/test/clang-tidy/checkers/readability/convert-member-functions-to-static-deducing-this.cpp b/clang-tools-extra/test/clang-tidy/checkers/readability/convert-member-functions-to-static-deducing-this.cpp
index a6ca86dd7cefa..790c8f0f927cc 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/readability/convert-member-functions-to-static-deducing-this.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/readability/convert-member-functions-to-static-deducing-this.cpp
@@ -20,3 +20,27 @@ struct Hello {
 
   void UnnamedExplicitObjectParam(this Hello &) {}
 };
+
+
+class OverloadedUnresolvedWithAutoLambda {
+public:
+  void CallsFunctionVar();
+  void CallsOverloadedMethodWithArg(int a);
+  void OverloadedMethodWithoutArg();
+  void OverloadedMethodWithArg(int a) { };
+};
+
+void OverloadedUnresolvedWithAutoLambda::CallsFunctionVar() {
+  // CHECK-MESSAGES: :[[@LINE-1]]:42: warning: method 'CallsFunctionVar' can be made static [readability-convert-member-functions-to-static]
+  auto fun = [&](auto a) {
+    var(a);
+  };
+}
+
+void OverloadedUnresolvedWithAutoLambda::CallsOverloadedMethodWithArg(int a) {
+  auto fun = [&](auto b) {
+    OverloadedMethodWithArg(b);
+  };
+}
+
+void Var(int a) { }

>From 3c3ee23e3a68d9db7600ece851a634fdd8f94b6e Mon Sep 17 00:00:00 2001
From: Gaurav Dhingra <gauravdhingra.gxyd at gmail.com>
Date: Sun, 12 Apr 2026 21:16:37 +0530
Subject: [PATCH 3/3] add ReleaseNotes entry

---
 clang-tools-extra/docs/ReleaseNotes.rst | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 02315415b975f..3f93f478e992d 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -412,6 +412,11 @@ Changes in existing checks
   - Reduce verbosity by removing the note indicating source location of the
     ``empty`` function.
 
+- Improved :doc:`readability-convert-member-functions-to-static
+  <clang-tidy/checks/readability/convert-member-functions-to-static>` check to
+  correctly detect ``this`` usage within a member function with a call to an
+  overloaded method inside a generic lambda.
+
 - Improved :doc:`readability-else-after-return
   <clang-tidy/checks/readability/else-after-return>` check: