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.
This commit is contained in:
Jason Merrill 2020-08-21 16:23:03 -04:00
parent b2b24d30bb
commit 6b958ee0fd
2 changed files with 8 additions and 10 deletions

View File

@ -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;
}
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

View File

@ -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(); };