When the pointer target type differs in a virtual override, the standard
requires the type in the derived class method to be complete. But that
shouldn't be necessary if the types only differ in cv-quals; this seems
like a wording bug, and EDG seems to agree.
Tested x86_64-pc-linux-gnu, applied to trunk.
commit 7dfcc5d7e1985a5727a097c2e664b5ded310d509
Author: Jason Merrill <ja...@redhat.com>
Date: Thu Mar 3 16:20:58 2011 -0500
PR c++/46220
* search.c (check_final_overrider): Allow pointer to same incomplete
class type with different cv-quals.
diff --git a/gcc/cp/search.c b/gcc/cp/search.c
index 188f0a5..07ec9ef 100644
--- a/gcc/cp/search.c
+++ b/gcc/cp/search.c
@@ -1835,11 +1835,17 @@ check_final_overrider (tree overrider, tree basefn)
if (CLASS_TYPE_P (base_return) && CLASS_TYPE_P (over_return))
{
- tree binfo = lookup_base (over_return, base_return,
- ba_check | ba_quiet, NULL);
+ /* Strictly speaking, the standard requires the return type to be
+ complete even if it only differs in cv-quals, but that seems
+ like a bug in the wording. */
+ if (!same_type_ignoring_top_level_qualifiers_p (base_return,
over_return))
+ {
+ tree binfo = lookup_base (over_return, base_return,
+ ba_check | ba_quiet, NULL);
- if (!binfo)
- fail = 1;
+ if (!binfo)
+ fail = 1;
+ }
}
else if (!pedantic
&& can_convert (TREE_TYPE (base_type), TREE_TYPE (over_type)))
diff --git a/gcc/testsuite/g++.dg/inherit/covariant19.C
b/gcc/testsuite/g++.dg/inherit/covariant19.C
new file mode 100644
index 0000000..22c2b0e
--- /dev/null
+++ b/gcc/testsuite/g++.dg/inherit/covariant19.C
@@ -0,0 +1,14 @@
+// PR c++/46220
+// According to the letter of the standard this is invalid,
+// but that seems like a bug.
+
+class Baz;
+class Foo {
+public:
+ virtual const Baz* getBaz() = 0;
+};
+class Bar : public Foo {
+public:
+ Baz* getBaz();
+};
+
