[Bug c++/35641] New: ICE on overload of friend function definition inside a class

[Bug c++/35641] New: ICE on overload of friend function definition inside a class

[philippe at fornux dot com]

The following:
**************

template <typename T>
    struct Message
    {
        friend ostream & operator << (ostream & out, const Message & self)
        {
            cout << __PRETTY_FUNCTION__ << endl;

            return out;
        }
    };


typedef Message<int> IntMsg;


inline ostream & operator << (ostream & out, const IntMsg & self)
{
    cout << __PRETTY_FUNCTION__ << endl;

    return out;
}

int main()
{
    IntMsg m;

    cout << m << endl;
}



Produces:
*********

templateoverload.cpp: In function `std::ostream& operator<<(std::ostream&,
const IntMsg&)':
templateoverload.cpp:33:   instantiated from here
templateoverload.cpp:0: internal compiler error: in change_decl_assembler_name,
at cgraph.c:541


Resolved with out-of-class definition:
**************************************

template <typename T>
    inline ostream & operator << (ostream & out, const Message<T> & self)
    {
        cout << __PRETTY_FUNCTION__ << endl;

        return out;
    }


-- 
           Summary: ICE on overload of friend function definition inside a
                    class
           Product: gcc
           Version: 3.4.5
            Status: UNCONFIRMED
          Severity: critical
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: philippe at fornux dot com
 GCC build triplet: gcc version 3.4.5 (mingw special)
  GCC host triplet: Windows XP
GCC target triplet: Mingw


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35641

[Bug c++/35641] ICE on overload of friend function definition inside a class

[fang at csl dot cornell dot edu]

------- Comment #1 from fang at csl dot cornell dot edu  2008-03-22 23:51 -------
In general, friend injection is not part of the standard, so best practice is
to declare before befriending.  


-- 

fang at csl dot cornell dot edu changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |fang at csl dot cornell dot
                   |                            |edu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35641

[Bug c++/35641] [4.1 regression] ICE on overload of friend function definition inside a class

[reichelt at gcc dot gnu dot org]

------- Comment #2 from reichelt at gcc dot gnu dot org  2008-03-29 17:11 -------
Here's a reduced testcase:

=====================================
template<int> struct A
{
  friend void foo(const A&)
  {
    __FUNCTION__;
  }
};

inline void foo(const A<0>&)
{
  __FUNCTION__;
}

void bar()
{
  foo(A<0>());
}
=====================================

The bug is fixed since GCC 4.2.0, as the code is correctly rejected:

bug.cc: In instantiation of 'A<0>':
bug.cc:17:   instantiated from here
bug.cc:4: error: redefinition of 'void foo(const A<0>&)'
bug.cc:10: error: 'void foo(const A<0>&)' previously defined here

On the 4.1 branch I still get an ICE, but after the above error message:

bug.cc: In instantiation of 'A<0>':
bug.cc:17:   instantiated from here
bug.cc:4: error: redefinition of 'void foo(const A<0>&)'
bug.cc:10: error: 'void foo(const A<0>&)' previously defined here
bug.cc:4: internal compiler error: tree check: expected var_decl or
function_decl or type_decl or template_decl, have error_mark in
tsubst_friend_function, at cp/pt.c:5352
Please submit a full bug report, [etc.]

Since we already rejected the code with GCC 3.1 - 3.3.6 this is a regression.
I don't think anybody will fix this minor problem on the 4.1 branch, though.

Btw, the code was wrongly accepted by GCC 4.0.0 - 4.1.1.


-- 

reichelt at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |reichelt at gcc dot gnu dot
                   |                            |org
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
           Keywords|                            |error-recovery, ice-on-
                   |                            |invalid-code
      Known to fail|                            |3.4.0 3.4.6 4.0.0 4.1.2
      Known to work|                            |3.1 3.3.6
   Last reconfirmed|0000-00-00 00:00:00         |2008-03-29 17:11:11
               date|                            |
            Summary|ICE on overload of friend   |[4.1 regression] ICE on
                   |function definition inside a|overload of friend function
                   |class                       |definition inside a class
   Target Milestone|---                         |4.1.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35641

[Bug c++/35641] [4.1 regression] ICE on overload of friend function definition inside a class

[jsm28 at gcc dot gnu dot org]

------- Comment #3 from jsm28 at gcc dot gnu dot org  2008-07-04 16:18 -------
Closing 4.1 branch.


-- 

jsm28 at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
      Known to fail|3.4.0 3.4.6 4.0.0 4.1.2     |3.4.0 3.4.6 4.0.0 4.1.2
                   |                            |4.1.3
      Known to work|3.1 3.3.6                   |3.1 3.3.6 4.2.0
         Resolution|                            |FIXED
   Target Milestone|4.1.3                       |4.2.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35641