Patchwork C++ PATCH for c++/52746 (virtual destructors broken in templates)

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Submitter Jason Merrill
Date March 29, 2012, 2:53 a.m.
Message ID <4F73CEA4.3080001@redhat.com>
Download mbox | patch
Permalink /patch/149356/
State New
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Comments

Jason Merrill - March 29, 2012, 2:53 a.m.
In my fix for PR 48051 I failed to audit all the users of 
adjust_result_of_qualified_name_lookup to make sure it wasn't being 
called for non-qualified lookups as well; in this case we were calling 
it for an explicit destructor call, and now that we set 
BASELINK_QUALIFIED_P in that function, we were suppressing virtual 
calling semantics inappropriately.

Tested x86_64-pc-linux-gnu, applying to trunk and 4.7.

Patch

commit 1f230c968d34b5c48ad50f83e8774de52d04d653
Author: Jason Merrill <jason@redhat.com>
Date:   Wed Mar 28 20:59:26 2012 -0400

    	PR c++/52746
    	* typeck.c (lookup_destructor): Clear BASELINK_QUALIFIED_P if
    	we didn't get an explicit scope.
    	* pt.c (tsubst_baselink): Likewise.

diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index f128947..9b410a7 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -11814,6 +11814,7 @@  tsubst_baselink (tree baselink, tree object_type,
     tree optype;
     tree template_args = 0;
     bool template_id_p = false;
+    bool qualified = BASELINK_QUALIFIED_P (baselink);
 
     /* A baselink indicates a function from a base class.  Both the
        BASELINK_ACCESS_BINFO and the base class referenced may
@@ -11862,9 +11863,12 @@  tsubst_baselink (tree baselink, tree object_type,
 
     if (!object_type)
       object_type = current_class_type;
-    return adjust_result_of_qualified_name_lookup (baselink,
-						   qualifying_scope,
-						   object_type);
+
+    if (qualified)
+      baselink = adjust_result_of_qualified_name_lookup (baselink,
+							 qualifying_scope,
+							 object_type);
+    return baselink;
 }
 
 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID.  DONE is
diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index b68de52..d2ed940 100644
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -2415,6 +2415,11 @@  lookup_destructor (tree object, tree scope, tree dtor_name)
 			tf_warning_or_error);
   expr = (adjust_result_of_qualified_name_lookup
 	  (expr, dtor_type, object_type));
+  if (scope == NULL_TREE)
+    /* We need to call adjust_result_of_qualified_name_lookup in case the
+       destructor names a base class, but we unset BASELINK_QUALIFIED_P so
+       that we still get virtual function binding.  */
+    BASELINK_QUALIFIED_P (expr) = false;
   return expr;
 }
 
diff --git a/gcc/testsuite/g++.dg/overload/virtual2.C b/gcc/testsuite/g++.dg/overload/virtual2.C
new file mode 100644
index 0000000..c93ba9e
--- /dev/null
+++ b/gcc/testsuite/g++.dg/overload/virtual2.C
@@ -0,0 +1,31 @@ 
+// PR c++/52746
+// { dg-do run }
+
+extern "C" int printf(const char*,...);
+extern "C" void abort();
+bool db;
+
+struct A
+{
+  virtual ~A() {}
+};
+
+struct B : public A
+{
+  virtual ~B() { db = true; }
+};
+
+template<int> void test()
+{
+  B * b = new B;
+  A * a = b;
+  a->~A();
+  ::operator delete(b);
+}
+
+int main()
+{
+  test<0>();
+  if (!db)
+    abort();
+}