[clang] [clang] [SemaCXX] Disallow deducing "this" on operator `new` and `delete` (PR #82251)

[Rajveer Singh Bharadwaj via cfe-commits]

https://github.com/Rajveer100 created https://github.com/llvm/llvm-project/pull/82251

Resolves Issue #82249

As described in the issue, any deallocation function for a `class X` is a static member (even if not explicitly declared static).

>From 3ad4e85144739e16be13a4d5641b24d1a7e5b00b Mon Sep 17 00:00:00 2001
From: Rajveer <rajveer.developer at icloud.com>
Date: Mon, 19 Feb 2024 19:29:48 +0530
Subject: [PATCH] [clang] [SemaCXX] Disallow deducing "this" on operator `new`
 and `delete`

Resolves Issue #82249
---
 clang/lib/Sema/SemaDeclCXX.cpp             | 4 +++-
 clang/test/SemaCXX/cxx2b-deducing-this.cpp | 4 ++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index ab8a967b06a456..7a7b544d82b640 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -11391,7 +11391,9 @@ void Sema::CheckExplicitObjectMemberFunction(Declarator &D,
         << ExplicitObjectParam->getSourceRange();
   }
 
-  if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_static) {
+  if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_static ||
+      (D.getContext() == clang::DeclaratorContext::Member &&
+       D.isStaticMember())) {
     Diag(ExplicitObjectParam->getBeginLoc(),
          diag::err_explicit_object_parameter_nonmember)
         << D.getSourceRange() << /*static=*/0 << IsLambda;
diff --git a/clang/test/SemaCXX/cxx2b-deducing-this.cpp b/clang/test/SemaCXX/cxx2b-deducing-this.cpp
index aab35828096a8e..530f8bf6af1b6b 100644
--- a/clang/test/SemaCXX/cxx2b-deducing-this.cpp
+++ b/clang/test/SemaCXX/cxx2b-deducing-this.cpp
@@ -16,6 +16,10 @@ struct S {
     static void f(this auto); // expected-error{{an explicit object parameter cannot appear in a static function}}
     virtual void f(this S); // expected-error{{an explicit object parameter cannot appear in a virtual function}}
 
+    // new and delete are implicitly static
+    void *operator new(this unsigned long); // expected-error{{an explicit object parameter cannot appear in a static function}}
+    void operator delete(this void*); // expected-error{{an explicit object parameter cannot appear in a static function}}
+    
     void g(this auto) const; // expected-error{{explicit object member function cannot have 'const' qualifier}}
     void h(this auto) &; // expected-error{{explicit object member function cannot have '&' qualifier}}
     void i(this auto) &&; // expected-error{{explicit object member function cannot have '&&' qualifier}}