[PATCH] D56405: Split -Wdelete-non-virtual-dtor into two groups

[Erik Pilkington via Phabricator via cfe-commits]

erik.pilkington created this revision.
erik.pilkington added reviewers: rsmith, aaron.ballman.
Herald added subscribers: dexonsmith, jkorous.

`-Wdelete-non-virtual-dtor` controlled two diagnostics: 1) calling a non-virtual dtor from an abstract class, and 2) calling a non-virtual dtor from a polymorphic class. 1) is a lot more severe than 2), since 1) is a guaranteed crash, but 2) is just "code smell". Previously, projects compiled with `-Wall -Wno-delete-non-virtual-dtor`, which is somewhat reasonable, silently crashed on 1).

rdar://40380564

Thanks for taking a look!


Repository:
  rC Clang

https://reviews.llvm.org/D56405

Files:
  clang/include/clang/Basic/DiagnosticGroups.td
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/test/SemaCXX/non-virtual-dtors.cpp


Index: clang/test/SemaCXX/non-virtual-dtors.cpp
===================================================================
--- /dev/null
+++ clang/test/SemaCXX/non-virtual-dtors.cpp
@@ -0,0 +1,32 @@
+// RUN: %clang_cc1 %s -verify -DDIAG1
+// RUN: %clang_cc1 %s -verify -DDIAG1 -DDIAG2 -Wdelete-non-virtual-dtor
+// RUN: %clang_cc1 %s -verify -DDIAG1         -Wmost -Wno-delete-non-virtual-dtor
+// RUN: %clang_cc1 %s -verify                 -Wmost -Wno-delete-abstract-non-virtual-dtor
+
+#ifndef DIAG1
+#ifndef DIAG2
+// expected-no-diagnostics
+#endif
+#endif
+
+struct S1 {
+  ~S1() {}
+  virtual void abs() = 0;
+};
+
+void f1(S1 *s1) { delete s1; }
+#ifdef DIAG1
+// expected-warning at -2 {{delete called on 'S1' that is abstract but has non-virtual destructor}}
+#endif
+
+struct Base {
+  virtual void abs() = 0;
+};
+struct S2 : Base {
+  ~S2() {}
+  void abs() {}
+};
+void f2(S2 *s2) { delete s2; }
+#ifdef DIAG2
+// expected-warning at -2 {{delete called on non-final 'S2' that has virtual functions but non-virtual destructor}}
+#endif
Index: clang/include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -6460,7 +6460,7 @@
   "qualify call to silence this warning">;
 def warn_delete_abstract_non_virtual_dtor : Warning<
   "%select{delete|destructor}0 called on %1 that is abstract but has "
-  "non-virtual destructor">, InGroup<DeleteNonVirtualDtor>, ShowInSystemHeader;
+  "non-virtual destructor">, InGroup<DeleteAbstractNonVirtualDtor>, ShowInSystemHeader;
 def warn_overloaded_virtual : Warning<
   "%q0 hides overloaded virtual %select{function|functions}1">,
   InGroup<OverloadedVirtual>, DefaultIgnore;
Index: clang/include/clang/Basic/DiagnosticGroups.td
===================================================================
--- clang/include/clang/Basic/DiagnosticGroups.td
+++ clang/include/clang/Basic/DiagnosticGroups.td
@@ -105,6 +105,8 @@
 
 def DeleteIncomplete : DiagGroup<"delete-incomplete">;
 def DeleteNonVirtualDtor : DiagGroup<"delete-non-virtual-dtor">;
+def DeleteAbstractNonVirtualDtor : DiagGroup<"delete-abstract-non-virtual-dtor",
+                                             [DeleteNonVirtualDtor]>;
 def AbstractFinalClass : DiagGroup<"abstract-final-class">;
 
 def CXX11CompatDeprecatedWritableStr :


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