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

[Reid Kleckner via cfe-commits]

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@@ -13,10 +15,41 @@ struct Bar {
 
 struct Baz {
   virtual ~Baz() {}
-  static void operator delete[](void* ptr) = delete; // expected-note {{explicitly marked deleted here}}
+  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;
 };
 
 void foobar() {
-  Baz *B = new Baz[10]();
+  Baz *B = new Baz[10](); // ms-error {{attempt to use a deleted function}}
   delete [] B; // expected-error {{attempt to use a deleted function}}
+  BarBaz *BB = new BarBaz[10]();
+}
+
+struct BaseDelete1 {
+  void operator delete[](void *); //ms-note 2{{member found by ambiguous name lookup}}
+};
+struct BaseDelete2 {
+  void operator delete[](void *); //ms-note 2{{member found by ambiguous name lookup}}
+};
+struct BaseDestructor {
+  BaseDestructor() {}
+  virtual ~BaseDestructor() = default;
+};
+struct Final : BaseDelete1, BaseDelete2, BaseDestructor {
+  Final() {}
+};
+
+#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
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rnk wrote:

Maybe throw in a third case for good measure: an explicit, inline, non-exported destructor, with ambiguous lookup. I'm guessing we want the same diagnostics we get for `Final`, i.e. we emit the diagnostic only when array-new gets called, as in the case with the implicit destructor.

https://github.com/llvm/llvm-project/pull/135041