[Bug c++/14281] New: Regression in v3.4: friend class not working

[Bug c++/14281] New: Regression in v3.4: friend class not working

[s_gccbugzilla at nedprod dot com]

With GCC v3.4 CVS 20040218 it thinks that ImplBase (typedefed within its parent) 
is private which it is - but the class which inherits off of it via template 
parameter is a friend.

I understand that friendship may not apply to base classes as it's not 
technically "in" the class yet. However my outdated version of the standard 
isn't clear here so I have no real way of knowing except that MSVC and GCC v3.2 
compile this fine.

g++ -fPIC -Wformat -Wno-reorder -Wno-non-virtual-dtor -march=i486 
-mcpu=athlon-xp -fexceptions -fkeep-inline-functions -g -DFOXDLL -DUSE_POSIX 
-DHAVE_CONSTTEMPORARIES -D_DEBUG -DHAVE_XSHM_H -DHAVE_XCURSOR_H=1 -DHAVE_XFT_H=1 
-DXTHREADS=1 -DFOX_THREAD_SAFE=1 -DHAVE_LIBDL=1 -DHAVE_CUPS_H=1 -DSTDC_HEADERS=1 
-DHAVE_SYS_TYPES_H=1 -DHAVE_SYS_STAT_H=1 -DHAVE_STDLIB_H=1 -DHAVE_STRING_H=1 
-DHAVE_MEMORY_H=1 -DHAVE_STRINGS_H=1 -DHAVE_INTTYPES_H=1 -DHAVE_STDINT_H=1 
-DHAVE_UNISTD_H=1 -DHAVE_DLFCN_H=1 -DTIME_WITH_SYS_TIME=1 -DHAVE_SYS_WAIT_H=1 
-DHAVE_DIRENT_H=1 -DHAVE_UNISTD_H=1 -DHAVE_SYS_PARAM_H=1 -DHAVE_SYS_SELECT_H=1 
-DBUILDING_TCOMMON -DFOXDLL_EXPORTS -DHAVE_JPEG_H -DHAVE_PNG_H -DHAVE_TIFF_H 
-DHAVE_ZLIB_H -DHAVE_OPENSSL -DHAVE_GL_H -DSUN_OGL_NO_VERTEX_MACROS 
-DHPOGL_SUPPRESS_FAST_API -DHAVE_GLU_H -ITnFOX/include -I/usr/kerberos/include 
-I/usr/X11R6/include -I/usr/include/freetype2 -Iinclude -c -o 
objs/Debug/TFileBySyncDev.os src/TFileBySyncDev.cxx
`-mcpu=' is deprecated. Use `-mtune=' or '-march=' instead.
src/TFileBySyncDev.cxx: In member function `FX::FXIPCChannel::HandledCode Tn::
TFileBySyncDevPrivate::msgReceived(FX::FXIPCMsg*)':
src/TFileBySyncDev.cxx:260: warning: converting of negative value `-0x000000001' 
to `unsigned int'
TnFOX/include/FXGenericTools.h: At global scope:
TnFOX/include/FXGenericTools.h: In instantiation of `FX::Generic::FunctorHelper:
:ImplMemFn<FX::Generic::Functor<FX::Generic::TL::item<FX::FXIPCChannel::
HandledCode, FX::Generic::TL::item<FX::FXIPCMsg*, FX::Generic::NullType> > >, 
Tn::TFileBySyncDevPrivate, FX::FXIPCChannel::HandledCode (Tn::
TFileBySyncDevPrivate::*)(FX::FXIPCMsg*)>':
TnFOX/include/FXGenericTools.h:1259:   instantiated from `FX::Generic::
Functor<parslist>::Functor(obj*, fn) [with obj = Tn::TFileBySyncDevPrivate, fn = 
FX::FXIPCChannel::HandledCode (Tn::TFileBySyncDevPrivate::*)(FX::FXIPCMsg*), 
parslist = FX::Generic::TL::item<FX::FXIPCChannel::HandledCode, FX::Generic::TL:
:item<FX::FXIPCMsg*, FX::Generic::NullType> >]'
src/TFileBySyncDev.cxx:297:   instantiated from here
TnFOX/include/FXGenericTools.h:1240: error: `typedef struct FX::Generic::
FunctorHelper::ImplBaseOp<FX::Generic::TL::item<FX::FXIPCChannel::HandledCode, 
FX::Generic::TL::item<FX::FXIPCMsg*, FX::Generic::NullType> >, 1> FX::Generic::
Functor<FX::Generic::TL::item<FX::FXIPCChannel::HandledCode, FX::Generic::TL::
item<FX::FXIPCMsg*, FX::Generic::NullType> > >::ImplBase' is private
TnFOX/include/FXGenericTools.h:1195: error: within this context
scons: *** [objs/Debug/TFileBySyncDev.os] Error 1

Cheers,
Niall

-- 
           Summary: Regression in v3.4: friend class not working
           Product: gcc
           Version: 3.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: s_gccbugzilla at nedprod dot com
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14281

[Bug c++/14281] Regression in v3.4: friend class not working

[s_gccbugzilla at nedprod dot com]

------- Additional Comments From s_gccbugzilla at nedprod dot com  2004-02-25 00:53 -------
Created an attachment (id=5793)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=5793&action=view)
Preprocessor output illustrating the bug (maybe)


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14281

[Bug c++/14281] Regression in v3.4: friend class not working

[giovannibajo at libero dot it]

------- Additional Comments From giovannibajo at libero dot it  2004-02-25 01:56 -------
Since you seem to know what's going on, maybe you can help us and provide a 
minimal snippet showing the problem?

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14281

[Bug c++/14281] Regression in v3.4: friend class not working

[reichelt at gcc dot gnu dot org]

------- Additional Comments From reichelt at gcc dot gnu dot org  2004-02-25 02:22 -------
Here's a minimal testcase showing the problem.
I guess, gcc is actually right when rejecting the code
(it does so since 3.3), but I'm not sure.

=====================================================
template <typename T> struct A : public T::X {};

class B
{
    template <typename> friend class A;
    struct X {};
};

A<B> a;
=====================================================


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14281

[Bug c++/14281] Regression in v3.4: friend class not working

[s_gccbugzilla at nedprod dot com]

------- Additional Comments From s_gccbugzilla at nedprod dot com  2004-02-25 03:29 -------
(In reply to comment #3)
> Here's a minimal testcase showing the problem.
> I guess, gcc is actually right when rejecting the code
> (it does so since 3.3), but I'm not sure.
> 
> =====================================================
> template <typename T> struct A : public T::X {};
> 
> class B
> {
>     template <typename> friend class A;
>     struct X {};
> };
> 
> A<B> a;
> =====================================================
> 

This is it in one. Now seeing as you guys are the experts, does inheriting off 
something observe that something's friend rules? ie; does the class begin before 
inheriting or after?

I should add I tested against v3.2 where it does work, not v3.3 which dies with 
certain code sequences in my code so I tend to avoid it (v3.4 has them fixed so 
I haven't reported these).

Cheers,
Niall


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14281

[Bug c++/14281] Regression in v3.4: friend class not working

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-02-25 04:44 -------
This is not a bug, ICC 6.0 rejects this code (but only when strict mode is turned on):
pr14281.cc
pr14281.cc(1): error #308: class "B::X" is inaccessible
  template <typename T> struct A : public T::X {};
                                             ^
          detected during instantiation of class "A<T> [with T=B]" at line 9

compilation aborted for pr14281.cc (code 2)

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |INVALID


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14281

[Bug c++/14281] Regression in v3.4: friend class not working

[giovannibajo at libero dot it]

------- Additional Comments From giovannibajo at libero dot it  2004-02-25 15:03 -------
Well, ICC/EDG might be wrong, especially if you use such an old version. 
Please, let's not close bugs only because another compiler behaves differently, 
even if it's EDG. 

Anyway, this bug is indeed invalid because of [class.friend]/2 in the C++ 
Standard, which says: "Also, because the base-clause of the friend class is not 
part of its member declarations, the base-clause of the friend class cannot 
access the names of the private and protected members from the class granting 
friendship."

So GCC is indeed correct.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14281

[Bug c++/14281] Regression in v3.4: friend class not working

[gdr at integrable-solutions dot net]

------- Additional Comments From gdr at integrable-solutions dot net  2004-02-25 15:18 -------
Subject: Re:  Regression in v3.4: friend class not working

"giovannibajo at libero dot it" <gcc-bugzilla@gcc.gnu.org> writes:


| Please, let's not close bugs only because another compiler behaves
| differently, even if it's EDG. 

Amen.  I wish we do not end up being a clone of EDG (I do intend to
diminish their values) or do whatever EDG does.

-- Gaby


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14281