[clang] [C++20] Destroying delete and deleted destructors (PR #118800)

[Richard Smith via cfe-commits]

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@@ -1200,21 +1200,35 @@ CanThrowResult Sema::canThrow(const Stmt *S) {
 
   case Expr::CXXDeleteExprClass: {
     auto *DE = cast<CXXDeleteExpr>(S);
-    CanThrowResult CT;
+    CanThrowResult CT = CT_Cannot;
     QualType DTy = DE->getDestroyedType();
     if (DTy.isNull() || DTy->isDependentType()) {
       CT = CT_Dependent;
     } else {
+      // C++20 [expr.delete]p6: If the value of the operand of the delete-
+      // expression is not a null pointer value and the selected deallocation
+      // function (see below) is not a destroying operator delete, the delete-
+      // expression will invoke the destructor (if any) for the object or the
+      // elements of the array being deleted.
+      //
+      // So if the destructor is virtual, we only look at the exception
+      // specification of the destructor regardless of what operator delete is
+      // selected. Otherwise, we look at the selected operator delete, and if
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zygoloid wrote:

This comment doesn't match the code, which always considers the `operator delete`.

Would it make sense to move `IsDtorCalled` onto `CXXDeleteExpr` so you can call it from here too?

https://github.com/llvm/llvm-project/pull/118800