http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57317
Bug ID: 57317
Summary: [4.8/4.9] Regression bogus and unsuppressable warning:
'YYY' has a base 'ZZZ' whose type uses the anonymous
namespace
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: ppluzhnikov at google dot com
Google reference: b/9004062
Quite similar, but not identical to PR 56641.
Test case:
// --- cut ---
# 1 "t.h"
template < typename T > struct integral_c {
static const T value = 0;
};
struct is_reference:integral_c < bool > { };
template < class > struct is_function_ptr_helper { };
template < bool > struct is_function_chooser;
template <> struct is_function_chooser <0 >
{
template < typename T > struct result_:is_function_ptr_helper < T * > { };
};
template < typename T > struct is_function_impl:is_function_chooser <
is_reference::value >::result_ < T > { };
#5 "t.cc"
namespace
{
class NonCloneable;
void fn1 ()
{
is_function_impl < NonCloneable > i;
}
}
// --- cut ---
Using current (r199023) trunk:
g++ -c t.ii
t.h: In instantiation of 'struct
is_function_chooser<false>::result_<{anonymous}::NonCloneable>':
t.h:13:32: required from 'struct is_function_impl<{anonymous}::NonCloneable>'
t.cc:10:39: required from here
t.h:10:34: warning:
'is_function_chooser<false>::result_<{anonymous}::NonCloneable>' has a base
'is_function_ptr_helper<{anonymous}::NonCloneable*>' whose type uses the
anonymous namespace [enabled by default]
Richard Smiths says:
I think GCC is upset that a type defined outside of the main source file
has a template argument that has internal linkage.
In principle, that's a valuable diagnostic: it's trying to tell you that
every time you include that header, you're going to get a different type,
and you're likely to have an ODR diagnostic.
However, in this case, it's a false positive, because this happened
while instantiating a template from the main source file (with a type
defined in the main source file, no less).
In addition, this warning isn't suppressable via -Wno-... parameter.
