Revert "[MS][clang] Error about ambiguous operator delete[] only when required (llvm#135041)"

This reverts commit 2b3aa56.

Author: Fznamznon

clang/lib/Sema/SemaDeclCXX.cpp

@@ -11097,23 +11097,15 @@ bool Sema::CheckDestructor(CXXDestructorDecl *Destructor) {
       DiagnoseUseOfDecl(OperatorDelete, Loc);
       MarkFunctionReferenced(Loc, OperatorDelete);
       Destructor->setOperatorDelete(OperatorDelete, ThisArg);
-      if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
-        // Lookup delete[] too in case we have to emit a vector deleting dtor;
-        DeclarationName VDeleteName =
-            Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete);
-        // Diagnose if there is no available operator delete[] found and the
-        // destructor is exported. Vector deleting dtor body emission requires
-        // operator delete[] to be present. Whenever the destructor is exported,
-        // we just always emit vector deleting dtor body, because we don't know
-        // if new[] will be used with the type outside of the library. Otherwise
-        // when the dtor is not exported then new[]/delete[] in the TU will make
-        // sure the operator is referenced and its uses diagnosed.
-        bool Diagnose =
-            Destructor->hasAttr<DLLExportAttr>() && Destructor->isDefined();
-        FunctionDecl *ArrOperatorDelete = FindDeallocationFunctionForDestructor(
-            Loc, RD, VDeleteName, Diagnose);
-        Destructor->setOperatorArrayDelete(ArrOperatorDelete);
-      }
+      // 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, /*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);
     }
   }
 

clang/lib/Sema/SemaExprCXX.cpp

@@ -3016,19 +3016,8 @@ bool Sema::FindAllocationFunctions(
       return true;
   }
 
-  // new[] will force emission of vector deleting dtor which needs delete[].
-  bool MaybeVectorDeletingDtor = false;
-  if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
-    if (AllocElemType->isRecordType() && IsArray) {
-      auto *RD =
-          cast<CXXRecordDecl>(AllocElemType->castAs<RecordType>()->getDecl());
-      CXXDestructorDecl *DD = RD->getDestructor();
-      MaybeVectorDeletingDtor = DD && DD->isVirtual() && !DD->isDeleted();
-    }
-  }
-
   // We don't need an operator delete if we're running under -fno-exceptions.
-  if (!getLangOpts().Exceptions && !MaybeVectorDeletingDtor) {
+  if (!getLangOpts().Exceptions) {
     OperatorDelete = nullptr;
     return false;
   }
@@ -3619,11 +3608,8 @@ bool Sema::FindDeallocationFunction(SourceLocation StartLoc, CXXRecordDecl *RD,
   // Try to find operator delete/operator delete[] in class scope.
   LookupQualifiedName(Found, RD);
 
-  if (Found.isAmbiguous()) {
-    if (!Diagnose)
-      Found.suppressDiagnostics();
+  if (Found.isAmbiguous())
     return true;
-  }
 
   Found.suppressDiagnostics();
 

clang/test/SemaCXX/gh134265.cpp

@@ -1,6 +1,4 @@
-// RUN: %clang_cc1 %s -verify=expected -fsyntax-only -triple=x86_64-unknown-linux-gnu
-// RUN: %clang_cc1 %s -verify=expected -fsyntax-only -triple=x86_64-unknown-linux-gnu -std=c++20
-// RUN: %clang_cc1 %s -verify=expected,ms -fms-extensions -fms-compatibility -triple=x86_64-pc-windows-msvc -DMS
+// RUN: %clang_cc1 %s -verify -fsyntax-only
 
 struct Foo {
   virtual ~Foo() {} // expected-error {{attempt to use a deleted function}}
@@ -15,46 +13,10 @@ struct Bar {
 
 struct Baz {
   virtual ~Baz() {}
-  static void operator delete[](void* ptr) = delete; // expected-note {{explicitly marked deleted here}}\
-                                                        ms-note{{explicitly marked deleted here}}}
-};
-
-struct BarBaz {
-  ~BarBaz() {}
-  static void operator delete[](void* ptr) = delete;
+  static void operator delete[](void* ptr) = delete; // expected-note {{explicitly marked deleted here}}
 };
 
 void foobar() {
-  Baz *B = new Baz[10](); // ms-error {{attempt to use a deleted function}}
+  Baz *B = new Baz[10]();
   delete [] B; // expected-error {{attempt to use a deleted function}}
-  BarBaz *BB = new BarBaz[10]();
-}
-
-struct BaseDelete1 {
-  void operator delete[](void *); //ms-note 3{{member found by ambiguous name lookup}}
-};
-struct BaseDelete2 {
-  void operator delete[](void *); //ms-note 3{{member found by ambiguous name lookup}}
-};
-struct BaseDestructor {
-  BaseDestructor() {}
-  virtual ~BaseDestructor() = default;
-};
-struct Final : BaseDelete1, BaseDelete2, BaseDestructor {
-  Final() {}
-};
-struct FinalExplicit : BaseDelete1, BaseDelete2, BaseDestructor {
-  FinalExplicit() {}
-  inline ~FinalExplicit() {}
-};
-
-#ifdef MS
-struct Final1 : BaseDelete1, BaseDelete2, BaseDestructor {
-  __declspec(dllexport) ~Final1() {} // ms-error {{member 'operator delete[]' found in multiple base classes of different types}}
-};
-#endif // MS
-
-void foo() {
-    Final* a = new Final[10](); // ms-error {{member 'operator delete[]' found in multiple base classes of different types}}
-    FinalExplicit* b = new FinalExplicit[10](); // ms-error {{member 'operator delete[]' found in multiple base classes of different types}}
 }