[Bug c++/11174] New: derived class can access protected base class member function through pointer to member function

[Bug c++/11174] New: derived class can access protected base class member function through pointer to member function

[mike.reed@amadron.com]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11174

           Summary: derived class can access protected base class member
                    function through pointer to member function
           Product: gcc
           Version: 3.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: mike.reed@amadron.com
                CC: gcc-bugs@gcc.gnu.org

Reading specs from /usr/gcc3local/lib/gcc-lib/i686-pc-linux-gnu/3.3/specs
Configured with: ../gcc-3.3/configure --prefix=/usr/gcc3local
--enable-languages=c,c++
Thread model: posix
gcc version 3.3




With the following code:


class A {
protected:
    void foo() {}
public:
    A();
};


class B : public A {
    void bar() {
        A a;
        a.foo();
        void (A::*pmf)() = &A::foo;  // 1
        (a.*pmf)();                  // 2
    }
};


Compilation gives:
g++ -W -Wall -ansi -pedantic -c pmf.cpp
pmf.cpp: In member function `void B::bar()':
pmf.cpp:3: error: `void A::foo()' is protected
pmf.cpp:12: error: within this context

Compilation exited abnormally with code 1 at Thu Jun 12 10:28:26


But note that I am able to call the protected member function of the external
object via a pointer to member function (PMF).

Looking at the C++ spec (11.5 example see void D2::mem...) I think the line
labelled 1 should be ill-formed but since the compiler doesn't think so I am
able to gain access to the protected function on the line labelled 2.

[Bug c++/11174] derived class can access protected base class member function through pointer to member function

[giovannibajo@libero.it]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain, Size: 895 bytes --]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11174


giovannibajo@libero.it changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2003-06-12 15:36:40
               date|                            |


------- Additional Comments From giovannibajo@libero.it  2003-06-12 15:36 -------
Confirmed. Reduced snippet:

---------------------------------
struct A 
{
protected:
    int a;
};

struct B : A 
{
    void foo() 
    {
        (void)&A::a;
    }
};
---------------------------------

This is accepted by any version of GCC but it is ill-formed (see the example in 
§11.5).

[Bug c++/11174] derived class can access protected base class member function through pointer to member function

[lerdsuwa@gcc.gnu.org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11174


lerdsuwa@gcc.gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2003-06-12 15:36:40         |2003-06-15 13:54:55
               date|                            |

[Bug c++/11174] derived class can access protected base class member function through pointer to member function

[lerdsuwa@gcc.gnu.org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11174


lerdsuwa@gcc.gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|3.4                         |---

[Bug c++/11174] derived class can access protected base class member function through pointer to member function

[lerdsuwa at gcc dot gnu dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11174


lerdsuwa at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |3.4

[Bug c++/11174] derived class can access protected base class member function through pointer to member function

[lerdsuwa at gcc dot gnu dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11174



------- Additional Comments From lerdsuwa at gcc dot gnu dot org  2003-08-18 14:03 -------
Patch submitted:

  http://gcc.gnu.org/ml/gcc-patches/2003-08/msg00998.html

[Bug c++/11174] derived class can access protected base class member function through pointer to member function

[lerdsuwa at gcc dot gnu dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11174


lerdsuwa at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED


------- Additional Comments From lerdsuwa at gcc dot gnu dot org  2003-08-19 12:55 -------
Fixed in the main trunk.

[Bug c++/11174] derived class can access protected base class member function through pointer to member function

[cvs-commit at gcc dot gnu dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11174



------- Additional Comments From cvs-commit at gcc dot gnu dot org  2003-08-19 12:55 -------
Subject: Bug 11174

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	lerdsuwa@gcc.gnu.org	2003-08-19 12:55:00

Modified files:
	gcc/cp         : ChangeLog init.c 
	gcc/testsuite  : ChangeLog 
	gcc/testsuite/g++.old-deja/g++.jason: access17.C 
Added files:
	gcc/testsuite/g++.dg/parse: access4.C access5.C 

Log message:
	PR c++/11174
	* init.c (build_offset_ref): Perform access checking for
	pointer to member correctly.
	
	* g++.dg/parse/access4.C: New test.
	* g++.dg/parse/access5.C: Likewise.
	* g++.old-deja/g++.jason/access17.C: Adjust error message.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/ChangeLog.diff?cvsroot=gcc&r1=1.3608&r2=1.3609
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/init.c.diff?cvsroot=gcc&r1=1.339&r2=1.340
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.2976&r2=1.2977
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/g++.dg/parse/access4.C.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/g++.dg/parse/access5.C.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/g++.old-deja/g++.jason/access17.C.diff?cvsroot=gcc&r1=1.5&r2=1.6

[Bug c++/11174] derived class can access protected base class member function through pointer to member function

[pinskia at gcc dot gnu dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11174


pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |richard dot kreckel at ginac
                   |                            |dot de


------- Additional Comments From pinskia at gcc dot gnu dot org  2003-09-01 03:54 -------
*** Bug 12119 has been marked as a duplicate of this bug. ***

[Bug c++/11174] derived class can access protected base class member function through pointer to member function

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-04-08 18:43 -------
*** Bug 14894 has been marked as a duplicate of this bug. ***

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |sebor at roguewave dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11174

[Bug c++/11174] derived class can access protected base class member function through pointer to member function

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-05-06 12:36 -------
*** Bug 15308 has been marked as a duplicate of this bug. ***

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |smelkov at mph1 dot phys dot
                   |                            |spbu dot ru


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11174

[Bug c++/11174] derived class can access protected base class member function through pointer to member function

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-05-15 18:25 -------
*** Bug 15468 has been marked as a duplicate of this bug. ***

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |murrayc at murrayc dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11174

[Bug c++/11174] derived class can access protected base class member function through pointer to member function

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-05-17 19:17 -------
Reopening for documentation.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |REOPENED
           Keywords|                            |documentation
         Resolution|FIXED                       |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11174

[Bug c++/11174] derived class can access protected base class member function through pointer to member function

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|lerdsuwa at gcc dot gnu dot |giovannibajo at libero dot
                   |org                         |it
             Status|REOPENED                    |ASSIGNED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11174

[Bug c++/11174] derived class can access protected base class member function through pointer to member function

[giovannibajo at libero dot it]

------- Additional Comments From giovannibajo at libero dot it  2004-05-17 19:30 -------
I'll take care of writing up changes.html/bugs.html for this. It affects more 
than pointer-to-members, and appears to be a FAQ.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11174

[Bug c++/11174] derived class can access protected base class member function through pointer to member function

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-05-25 14:38 -------
Closing this one as PR 14949 is the one for the documenation.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11174