[clang] 16a1d5d - [clang] Do not diagnose unused deleted operator delete[] (#134357)

[via cfe-commits]

Author: Mariya Podchishchaeva
Date: 2025-04-04T14:44:44+02:00
New Revision: 16a1d5d51f6bafa19afc140b033db2cfb090743a

URL: https://github.com/llvm/llvm-project/commit/16a1d5d51f6bafa19afc140b033db2cfb090743a
DIFF: https://github.com/llvm/llvm-project/commit/16a1d5d51f6bafa19afc140b033db2cfb090743a.diff

LOG: [clang] Do not diagnose unused deleted operator delete[] (#134357)

For vector deleting dtors support we now also search and save operator
delete[]. Avoid diagnosing deleted operator delete[] when doing that
because vector deleting dtors are only called when delete[] is present
and whenever delete[] is present in the TU it will be diagnosed
correctly.

Fixes https://github.com/llvm/llvm-project/issues/134265

Added: 
    clang/test/SemaCXX/gh134265.cpp

Modified: 
    clang/include/clang/AST/DeclCXX.h
    clang/include/clang/Sema/Sema.h
    clang/lib/AST/DeclCXX.cpp
    clang/lib/Sema/SemaDeclCXX.cpp
    clang/lib/Sema/SemaExprCXX.cpp

Removed: 
    


################################################################################
diff  --git a/clang/include/clang/AST/DeclCXX.h b/clang/include/clang/AST/DeclCXX.h
index 764f85b04e6a0..56cec07ec0293 100644
--- a/clang/include/clang/AST/DeclCXX.h
+++ b/clang/include/clang/AST/DeclCXX.h
@@ -2878,7 +2878,7 @@ class CXXDestructorDecl : public CXXMethodDecl {
   static CXXDestructorDecl *CreateDeserialized(ASTContext &C, GlobalDeclID ID);
 
   void setOperatorDelete(FunctionDecl *OD, Expr *ThisArg);
-  void setOperatorArrayDelete(FunctionDecl *OD, Expr *ThisArg);
+  void setOperatorArrayDelete(FunctionDecl *OD);
 
   const FunctionDecl *getOperatorDelete() const {
     return getCanonicalDecl()->OperatorDelete;

diff  --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index b835697f99670..6bf1caf6bdd18 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -8336,7 +8336,8 @@ class Sema final : public SemaBase {
                                               DeclarationName Name);
   FunctionDecl *FindDeallocationFunctionForDestructor(SourceLocation StartLoc,
                                                       CXXRecordDecl *RD,
-                                                      DeclarationName Name);
+                                                      DeclarationName Name,
+                                                      bool Diagnose = true);
 
   /// ActOnCXXDelete - Parsed a C++ 'delete' expression (C++ 5.3.5), as in:
   /// @code ::delete ptr; @endcode

diff  --git a/clang/lib/AST/DeclCXX.cpp b/clang/lib/AST/DeclCXX.cpp
index 7aa710ad7309b..fffc50eb0b078 100644
--- a/clang/lib/AST/DeclCXX.cpp
+++ b/clang/lib/AST/DeclCXX.cpp
@@ -3031,8 +3031,7 @@ void CXXDestructorDecl::setOperatorDelete(FunctionDecl *OD, Expr *ThisArg) {
   }
 }
 
-void CXXDestructorDecl::setOperatorArrayDelete(FunctionDecl *OD,
-                                               Expr *ThisArg) {
+void CXXDestructorDecl::setOperatorArrayDelete(FunctionDecl *OD) {
   auto *First = cast<CXXDestructorDecl>(getFirstDecl());
   if (OD && !First->OperatorArrayDelete)
     First->OperatorArrayDelete = OD;

diff  --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 07379c6876731..b86f7118e0b34 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -11048,12 +11048,12 @@ bool Sema::CheckDestructor(CXXDestructorDecl *Destructor) {
       // Lookup delete[] too in case we have to emit a vector deleting dtor;
       DeclarationName VDeleteName =
           Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete);
-      FunctionDecl *ArrOperatorDelete =
-          FindDeallocationFunctionForDestructor(Loc, RD, VDeleteName);
+      FunctionDecl *ArrOperatorDelete = FindDeallocationFunctionForDestructor(
+          Loc, RD, VDeleteName, /*Diagnose=*/false);
       // delete[] in the TU will make sure the operator is referenced and its
       // uses diagnosed, otherwise vector deleting dtor won't be called anyway,
       // so just record it in the destructor.
-      Destructor->setOperatorArrayDelete(ArrOperatorDelete, ThisArg);
+      Destructor->setOperatorArrayDelete(ArrOperatorDelete);
     }
   }
 

diff  --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index e43f5e3f75bfe..d5f52cd5853f0 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -3265,11 +3265,13 @@ FunctionDecl *Sema::FindUsualDeallocationFunction(SourceLocation StartLoc,
   return Result.FD;
 }
 
-FunctionDecl *Sema::FindDeallocationFunctionForDestructor(
-    SourceLocation Loc, CXXRecordDecl *RD, DeclarationName Name) {
+FunctionDecl *Sema::FindDeallocationFunctionForDestructor(SourceLocation Loc,
+                                                          CXXRecordDecl *RD,
+                                                          DeclarationName Name,
+                                                          bool Diagnose) {
 
   FunctionDecl *OperatorDelete = nullptr;
-  if (FindDeallocationFunction(Loc, RD, Name, OperatorDelete))
+  if (FindDeallocationFunction(Loc, RD, Name, OperatorDelete, Diagnose))
     return nullptr;
   if (OperatorDelete)
     return OperatorDelete;

diff  --git a/clang/test/SemaCXX/gh134265.cpp b/clang/test/SemaCXX/gh134265.cpp
new file mode 100644
index 0000000000000..c7bdeb2add0cc
--- /dev/null
+++ b/clang/test/SemaCXX/gh134265.cpp
@@ -0,0 +1,22 @@
+// RUN: %clang_cc1 %s -verify -fsyntax-only
+
+struct Foo {
+  virtual ~Foo() {} // expected-error {{attempt to use a deleted function}}
+  static void operator delete(void* ptr) = delete; // expected-note {{explicitly marked deleted here}}
+};
+
+
+struct Bar {
+  virtual ~Bar() {}
+  static void operator delete[](void* ptr) = delete;
+};
+
+struct Baz {
+  virtual ~Baz() {}
+  static void operator delete[](void* ptr) = delete; // expected-note {{explicitly marked deleted here}}
+};
+
+void foobar() {
+  Baz *B = new Baz[10]();
+  delete [] B; // expected-error {{attempt to use a deleted function}}
+}