[clang] [Clang] fix overload resolution for object parameters with top-level cv-qualifiers in member functions (PR #110435)

[Oleksandr T. via cfe-commits]

https://github.com/a-tarasyuk updated https://github.com/llvm/llvm-project/pull/110435

>From c52634882631a71fad956a70179b480abf13006a Mon Sep 17 00:00:00 2001
From: Oleksandr T <oleksandr.tarasiuk at outlook.com>
Date: Sun, 29 Sep 2024 22:01:38 +0300
Subject: [PATCH] [Clang] fix overload resolution for object parameters with
 top-level cv-qualifiers in member functions

---
 clang/docs/ReleaseNotes.rst                | 1 +
 clang/lib/Sema/SemaOverload.cpp            | 3 +++
 clang/test/SemaCXX/cxx2b-deducing-this.cpp | 7 +++++++
 3 files changed, 11 insertions(+)

diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 28c759538f7df6..1bec2838765dab 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -447,6 +447,7 @@ Bug Fixes to C++ Support
 - Fixed an assertion failure in debug mode, and potential crashes in release mode, when
   diagnosing a failed cast caused indirectly by a failed implicit conversion to the type of the constructor parameter.
 - Fixed an assertion failure by adjusting integral to boolean vector conversions (#GH108326)
+- Fixed overload handling for object parameters with top-level cv-qualifiers in explicit member functions (#GH100394)
 
 Bug Fixes to AST Handling
 ^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index 0c1e054f7c30a4..7c40bab70bbe9d 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -1511,6 +1511,9 @@ static bool IsOverloadOrOverrideImpl(Sema &SemaRef, FunctionDecl *New,
       auto NewObjectType = New->getFunctionObjectParameterReferenceType();
       auto OldObjectType = Old->getFunctionObjectParameterReferenceType();
 
+      if (NewObjectType.isConstQualified() != OldObjectType.isConstQualified())
+        return false;
+
       auto IsImplicitWithNoRefQual = [](const CXXMethodDecl *F) {
         return F->getRefQualifier() == RQ_None &&
                !F->isExplicitObjectMemberFunction();
diff --git a/clang/test/SemaCXX/cxx2b-deducing-this.cpp b/clang/test/SemaCXX/cxx2b-deducing-this.cpp
index 63bf92e8d5edd3..5fd02502ce6df4 100644
--- a/clang/test/SemaCXX/cxx2b-deducing-this.cpp
+++ b/clang/test/SemaCXX/cxx2b-deducing-this.cpp
@@ -1073,3 +1073,10 @@ int main() {
   return foo[]; // expected-error {{no viable overloaded operator[] for type 'Foo'}}
 }
 }
+
+namespace GH100394 {
+struct C {
+  void f(this const C);
+  void f() const ;      // ok
+};
+}