re PR c++/67184 (Missed optimization with C++11 final specifier)

/cp
2019-05-21  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/67184
	PR c++/69445
	* call.c (build_over_call): Devirtualize when the final overrider
	comes from the base.

/testsuite
2019-05-21  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/67184
	PR c++/69445
	* g++.dg/other/final3.C: New.
	* g++.dg/other/final4.C: Likewise.
	* g++.dg/other/final5.C: Likewise.

From-SVN: r271490

gcc/cp/ChangeLog

+2019-05-21  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/67184
+	PR c++/69445
+	* call.c (build_over_call): Devirtualize when the final overrider
+	comes from the base.
+
 2019-05-21  Nathan Sidwell  <nathan@acm.org>
 
 	* name-lookup.c (do_nonmember_using_decl): Drop INSERT_P

gcc/cp/call.c

@@ -8244,7 +8244,7 @@ build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain)
       /* See if the function member or the whole class type is declared
 	 final and the call can be devirtualized.  */
       if (DECL_FINAL_P (fn)
-	  || CLASSTYPE_FINAL (TYPE_METHOD_BASETYPE (TREE_TYPE (fn))))
+	  || CLASSTYPE_FINAL (TREE_TYPE (argtype)))
 	flags |= LOOKUP_NONVIRTUAL;
 
       /* [class.mfct.nonstatic]: If a nonstatic member function of a class

gcc/testsuite/ChangeLog

+2019-05-21  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/67184
+	PR c++/69445
+	* g++.dg/other/final3.C: New.
+	* g++.dg/other/final4.C: Likewise.
+	* g++.dg/other/final5.C: Likewise.
+
 2019-05-21  Marek Polacek  <polacek@redhat.com>
 
 	DR 1940 - static_assert in anonymous unions.

gcc/testsuite/g++.dg/other/final3.C

+// PR c++/67184
+// { dg-do compile { target c++11 } }
+// { dg-options "-fdump-tree-original"  }
+
+struct V {
+ virtual void foo(); 
+};
+
+struct wV final : V {
+};
+
+struct oV final : V {
+  void foo();
+};
+
+void call(wV& x)
+{
+  x.foo();
+  x.V::foo();
+}
+
+void call(oV& x)
+{
+  x.foo();
+  x.V::foo();
+}
+
+// { dg-final { scan-tree-dump-times "OBJ_TYPE_REF" 0 "original" } }

gcc/testsuite/g++.dg/other/final4.C

+// PR c++/67184
+// { dg-do compile { target c++11 } }
+// { dg-options "-fdump-tree-original"  }
+
+struct B
+{
+  virtual void operator()();
+  virtual operator int();
+  virtual int operator++();
+};
+
+struct D final : B { };
+
+void foo(D& d) { d(); int t = d; ++d; }
+
+// { dg-final { scan-tree-dump-times "OBJ_TYPE_REF" 0 "original" } }