From: Jason Merrill <jason@redhat.com>
Date: Fri, 21 Aug 2020 20:23:03 +0000 (-0400)
Subject: c++: Emit as-base 'tor symbols for final class.  [PR95428]
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=6b958ee0fd0e1b2a2b22784ffbe531ed74358a22;p=gcc.git

c++: Emit as-base 'tor symbols for final class.  [PR95428]

For PR70462 I stopped emitting the as-base constructor and destructor
variants for final classes, because they can never be called.  Except that
it turns out that clang calls base variants from complete variants, even for
classes with virtual bases, and in some cases inlines them such that the
calls to the base variant are exposed.  So we need to continue to emit the
as-base symbols, even though they're unreachable by G++-compiled code.

gcc/cp/ChangeLog:

	PR c++/95428
	* optimize.c (populate_clone_array): Revert PR70462 change.
	(maybe_clone_body): Likewise.

gcc/testsuite/ChangeLog:

	* g++.dg/other/final8.C: Adjust expected output.
---

diff --git a/gcc/cp/optimize.c b/gcc/cp/optimize.c
index abdcd7fa19f..00621d636bf 100644
--- a/gcc/cp/optimize.c
+++ b/gcc/cp/optimize.c
@@ -244,19 +244,13 @@ populate_clone_array (tree fn, tree *fns)
   fns[1] = NULL_TREE;
   fns[2] = NULL_TREE;
 
-  tree ctx = DECL_CONTEXT (fn);
-
   FOR_EACH_CLONE (clone, fn)
     if (DECL_NAME (clone) == complete_dtor_identifier
 	|| DECL_NAME (clone) == complete_ctor_identifier)
       fns[1] = clone;
     else if (DECL_NAME (clone) == base_dtor_identifier
 	     || DECL_NAME (clone) == base_ctor_identifier)
-      {
-	/* We don't need to define the base variants for a final class.  */
-	if (!CLASSTYPE_FINAL (ctx))
-	  fns[0] = clone;
-      }
+      fns[0] = clone;
     else if (DECL_NAME (clone) == deleting_dtor_identifier)
       fns[2] = clone;
     else
@@ -481,7 +475,7 @@ maybe_clone_body (tree fn)
 
   /* Remember if we can't have multiple clones for some reason.  We need to
      check this before we remap local static initializers in clone_body.  */
-  if (!tree_versionable_function_p (fn) && fns[0] && fns[1])
+  if (!tree_versionable_function_p (fn))
     need_alias = true;
 
   /* We know that any clones immediately follow FN in the TYPE_FIELDS
diff --git a/gcc/testsuite/g++.dg/other/final8.C b/gcc/testsuite/g++.dg/other/final8.C
index f90f94e9ea0..67c87112353 100644
--- a/gcc/testsuite/g++.dg/other/final8.C
+++ b/gcc/testsuite/g++.dg/other/final8.C
@@ -1,6 +1,10 @@
+// PR c++/70462
+// PR c++/95428
 // { dg-do compile { target c++11 } }
-// { dg-final { scan-assembler-not "_ZN1BC2Ev" } }
-// { dg-final { scan-assembler-not "_ZN1BD2Ev" } }
+// { dg-final { scan-assembler "_ZN1BC1Ev" } }
+// { dg-final { scan-assembler "_ZN1BC2Ev" } }
+// { dg-final { scan-assembler "_ZN1BD2Ev" } }
+// { dg-final { scan-assembler "_ZN1BD1Ev" } }
 
 struct A { int i; A(); virtual ~A() = 0; };
 struct B final: public virtual A { int j; B(); ~B(); };