[Bug c++/17210] New: Erroneous behaviour of friend declaration

[Bug c++/17210] New: Erroneous behaviour of friend declaration

[victor dot judin at materna dot de]

During the compilation of the following source
1  class A{
     2  private:
     3          int F();
     4  public:
     5          A();
     6          ~A();
     7  };
     8
     9  class B{
    10  friend int A::F();
    11  //friend class A;
    12          int f( int );
    13  public:
    14          B();
    15          ~B();
    16          void Foo( int );
    17  };
    18
    19  int A::F()
    20  {
    21          B b;
    22          return  b.f( 1 );
    23  }
 comes the following error( "Fehler" means an error in German ):
bash-2.05$ g++ -c A.cpp
A.cpp:3: Fehler: `int A::F()' is private
A.cpp:10: Fehler: within this context

However, if the whole class A has been declared as a friend, i.e. 

 10  //friend int A::F();
 11  friend class A;

the compiler accepts it - the private member A::F works as a friend of B. As to
my knowledege, the access of friends is not of any importance - here's an
example from the Stroutsrup's "The C++ Programming Language ", 5.4.1:
1 class x {
2  // ...
3  void f();
4 };
5
6 class y {
7 // 
8 friend void x::f();
9 };
As you see, in this sample there is no mention at all whether the X::f() is
private, public or protected. Also the ISO/IEC C++ does not mention( at least
explicitly ) any restrictions. The code above works with GCC3.3.1, but not with
3.4.1. It is completely illogical to forbid the private member to be DECLARED as
a friend, but to allow the same function to ACT as a friend if the whole class
is friend-declared.
Here is again the gcc output:
bash-2.05$ gcc -v -save-temps -c A.cpp
Lese Spezifikationen von /opt/sfw/gcc-3.4/lib/gcc/sparc-sun-solaris2.9/3.4.1/specs
Konfiguriert mit: ../gcc-3.4.1/configure --enable-shared --enable-threads
--prefix=/opt/sfw/gcc-3.4
Thread-Modell: posix
gcc-Version 3.4.1
 /opt/sfw/gcc-3.4/libexec/gcc/sparc-sun-solaris2.9/3.4.1/cc1plus -E -quiet -v
A.cpp -mcpu=v7 -o A.ii
nicht vorhandenes Verzeichnis
»/opt/sfw/gcc-3.4/lib/gcc/sparc-sun-solaris2.9/3.4.1/../../../../sparc-sun-solaris2.9/include«
wird ignoriert
#include "..." - Suche beginnt hier:
#include <...> - Suche beginnt hier:
 /opt/sfw/gcc-3.4/lib/gcc/sparc-sun-solaris2.9/3.4.1/../../../../include/c++/3.4.1
 /opt/sfw/gcc-3.4/lib/gcc/sparc-sun-solaris2.9/3.4.1/../../../../include/c++/3.4.1/sparc-sun-solaris2.9
 /opt/sfw/gcc-3.4/lib/gcc/sparc-sun-solaris2.9/3.4.1/../../../../include/c++/3.4.1/backward
 /usr/local/include
 /opt/sfw/gcc-3.4/include
 /opt/sfw/gcc-3.4/lib/gcc/sparc-sun-solaris2.9/3.4.1/include
 /usr/include
Ende der Suchliste.
 /opt/sfw/gcc-3.4/libexec/gcc/sparc-sun-solaris2.9/3.4.1/cc1plus -fpreprocessed
A.ii -quiet -dumpbase A.cpp -mcpu=v7 -auxbase A -version -o A.s
GNU C++ version 3.4.1 (sparc-sun-solaris2.9)
        compiled by GNU C version 2.95.3.2 20010315 (release) (std::string patch).
GGC-Heuristik: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
A.cpp:3: Fehler: `int A::F()' is private
A.cpp:10: Fehler: within this context

-- 
           Summary: Erroneous behaviour of friend declaration
           Product: gcc
           Version: 3.4.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: victor dot judin at materna dot de
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: 3.4.1
  GCC host triplet: SunOS XXXX 5.9 Generic_112233-11 sun4u sparc SUNW,Ultra-
                    80


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17210

[Bug c++/17210] Erroneous behaviour of friend declaration

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-08-27 08:42 -------
Not a bug and a dup of bug 11952.
>From that dup bug:
According to the standard [class.friend] 11.4 Friends
7 A name nominated by a friend declaration shall be accessible in the scope of
the class containing the friend declaration. The meaning of the friend
declaration is the same whether the friend declaration appears in the private,
protected or public (9.2) portion of the class member-specification.

*** This bug has been marked as a duplicate of 11952 ***

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17210