[Bug c++/20028] New: problem with protected members in template inheritance

[Bug c++/20028] New: problem with protected members in template inheritance

[jcobyrne at cox dot net]

Apparently g++ isn't recognizing protected members in inheritance before the 
class declaration.  Furthermore, G++ segfaults when adding the first line, and 
the friend class.

----------------------

zehly@lain:~ $ cat a.cc
class Foo;

template <class T> class A
{ friend class Foo; protected: typedef T someType; };

template <class T> class B
{ protected: typedef T anotherType; };

template <typename T, template <class> class X, template <class> class Y>
class Foo : public X <T>, public Y <typename X<T>::someType>
{ typedef Y<typename X<T>::someType> yetAnotherType; };

int main ()
{ Foo<int, A, B> x; return 0; }

-------------

zehly@lain:~ $ g++40 -v -save-temps -o a a.cc
Using built-in specs.
Configured with: ./..//gcc-4.0-20050130/configure --disable-nls --with-system-
zlib --with-libiconv-prefix=/usr/local --program-suffix=40 --with-gxx-include-
dir=/usr/local/lib/gcc/i386-portbld-freebsd5.3/4.0.0/include/c++/ --disable-
shared --disable-libgcj --prefix=/usr/local i386-portbld-freebsd5.3
Thread model: posix
gcc version 4.0.0 20050130 (experimental) [FreeBSD]
 /usr/local/libexec/gcc/i386-portbld-freebsd5.3/4.0.0/cc1plus -E -quiet -v 
a.cc -fpch-preprocess -o a.ii
ignoring nonexistent directory "/usr/local/lib/gcc/i386-portbld-
freebsd5.3/4.0.0/../../../../i386-portbld-freebsd5.3/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/local/lib/gcc/i386-portbld-freebsd5.3/4.0.0/include/c++/
 /usr/local/lib/gcc/i386-portbld-freebsd5.3/4.0.0/include/c++//i386-portbld-
freebsd5.3
 /usr/local/lib/gcc/i386-portbld-freebsd5.3/4.0.0/include/c++//backward
 /usr/local/include
 /usr/local/lib/gcc/i386-portbld-freebsd5.3/4.0.0/include
 /usr/include
End of search list.
 /usr/local/libexec/gcc/i386-portbld-freebsd5.3/4.0.0/cc1plus -fpreprocessed 
a.ii -quiet -dumpbase a.cc -auxbase a -version -o a.s
GNU C++ version 4.0.0 20050130 (experimental) [FreeBSD] (i386-portbld-
freebsd5.3)
        compiled by GNU C version 4.0.0 20050130 (experimental) [FreeBSD].
GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
a.cc:10: error: 'Foo' is not a template type
a.cc: In function 'int main()':
a.cc:14: error: 'Foo' is not a template
a.cc:13: internal compiler error: Segmentation fault
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.

----------------------

zehly@lain:~ $ cat a.ii
# 1 "a.cc"
# 1 "<built-in>"
# 1 "<command line>"
# 1 "a.cc"
class Foo;

template <class T> class A
{ friend class Foo; protected: typedef T someType; };

template <class T> class B
{ protected: typedef T anotherType; };

template <typename T, template <class> class X, template <class> class Y>
class Foo : public X <T>, public Y <typename X<T>::someType>
{ typedef Y<typename X<T>::someType> yetAnotherType; };

int main ()
{ Foo<int, A, B> x; return 0; }

-- 
           Summary: problem with protected members in template inheritance
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: jcobyrne at cox dot net
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20028

[Bug c++/20028] problem with protected members in template inheritance

[jcobyrne at cox dot net]

------- Additional Comments From jcobyrne at cox dot net  2005-02-17 16:08 -------
By the way, when removing the friend class and line 1 of the source file, the 
code WILL compile on g++3.2.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20028

[Bug c++/20028] [3.4/4.0 Regression] class and then template class gives an ICE

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-02-17 17:55 -------
The code is invalid.
But this is a regression from 3.3.3 where we did not ICE.
Reduced testcase:
class Foo;
template <typename T> class Foo { };
int main ()
{
  Foo<int> x;
  return 0;
}


-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
           Keywords|                            |error-recovery, ice-on-
                   |                            |invalid-code
   Last reconfirmed|0000-00-00 00:00:00         |2005-02-17 17:55:25
               date|                            |
            Summary|problem with protected      |[3.4/4.0 Regression] class
                   |members in template         |and then template class
                   |inheritance                 |gives an ICE
   Target Milestone|---                         |3.4.4


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20028

[Bug c++/20028] [3.4/4.0 Regression] class and then template class gives an ICE

[aoliva at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |aoliva at gcc dot gnu dot
                   |dot org                     |org
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2005-02-17 17:55:25         |2005-02-17 19:09:18
               date|                            |
   Target Milestone|3.4.4                       |---


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20028

[Bug c++/20028] [3.4/4.0 Regression] class and then template class gives an ICE

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-02-17 19:25 -------
Subject: Bug 20028

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	aoliva@gcc.gnu.org	2005-02-17 19:25:05

Modified files:
	gcc/cp         : ChangeLog class.c 
	gcc/testsuite  : ChangeLog 
Added files:
	gcc/testsuite/g++.dg/template: crash34.C 

Log message:
	gcc/cp/ChangeLog:
	PR c++/20028
	* class.c (finish_struct): Initialize TYPE_SIZE_UNIT of a
	template along with TYPE_SIZE.
	gcc/testsuite/ChangeLog:
	PR c++/20028
	* g++.dg/template/crash34.C: New.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/ChangeLog.diff?cvsroot=gcc&r1=1.4632&r2=1.4633
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/class.c.diff?cvsroot=gcc&r1=1.705&r2=1.706
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.5043&r2=1.5044
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/g++.dg/template/crash34.C.diff?cvsroot=gcc&r1=NONE&r2=1.1



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20028

[Bug c++/20028] [3.4 Regression] class and then template class gives an ICE

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-02-17 20:02 -------
Patch here: <http://gcc.gnu.org/ml/gcc-patches/2005-02/msg01020.html> for 3.4.x.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |patch
            Summary|[3.4/4.0 Regression] class  |[3.4 Regression] class and
                   |and then template class     |then template class gives an
                   |gives an ICE                |ICE
   Target Milestone|---                         |3.4.4


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20028

[Bug c++/20028] [3.4 Regression] class and then template class gives an ICE

[jcobyrne at cox dot net]

------- Additional Comments From jcobyrne at cox dot net  2005-02-17 21:09 -------
(In reply to comment #4)
> Patch here: <http://gcc.gnu.org/ml/gcc-patches/2005-02/msg01020.html> for 
3.4.x.

The following code _IS_ correct and _DOES_ compile on 3.2.

template <class T> class A
{ protected: typedef T someType; };

template <class T> class B
{ protected: typedef T anotherType; };

// we should be able to access protected members of classes X and Y here,
// because we are inheriting them.
template <typename T, template <class> class X, template <class> class Y>
class Foo : public X <T>, public Y <typename X<T>::someType>
{ typedef Y<typename X<T>::someType> yetAnotherType; };

int main ()
{ Foo<int, A, B> x; return 0; }

-----------

I guess I stumbled on the segfault by mistake in my vain attempts to get the 
code to compile on 3.3 and greater.  Syntactically and semantically, I have 
confirmed that this code does work, and it is also used similarly in 
Alexandrescu's book on C++ Design Patterns.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20028

[Bug c++/20028] [3.4 Regression] class and then template class gives an ICE

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-02-17 21:14 -------
(In reply to comment #5)
> (In reply to comment #4)
> I guess I stumbled on the segfault by mistake in my vain attempts to get the 
> code to compile on 3.3 and greater.  Syntactically and semantically, I have 
> confirmed that this code does work, and it is also used similarly in 
> Alexandrescu's book on C++ Design Patterns.

Yes you did stumbled on the segfault but note this is not valid code still, yes a C++ book can get it 
wrong.




-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20028

[Bug c++/20028] [3.4 Regression] class and then template class gives an ICE

[jcobyrne at cox dot net]

------- Additional Comments From jcobyrne at cox dot net  2005-02-17 21:21 -------
If the code is wrong, what accounts for the fact that wrong code would compile 
on 3.2 and not on 3.3 or 3.4?  Also, Alexandrescu did not write it wrong, as it 
is also used in his Loki library that is known to compile under GCC as well as 
other compilers.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20028

[Bug c++/20028] [3.4 Regression] class and then template class gives an ICE

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-02-17 21:26 -------
(In reply to comment #7)
> If the code is wrong, what accounts for the fact that wrong code would compile 
> on 3.2 and not on 3.3 or 3.4?  Also, Alexandrescu did not write it wrong, as it 
> is also used in his Loki library that is known to compile under GCC as well as 
> other compilers.

Because it was a bug in 3.2 and before.  It does not compile with a slightly older EDG front-end.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20028

[Bug c++/20028] [3.4 Regression] class and then template class gives an ICE

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-02-21 21:11 -------
Subject: Bug 20028

CVSROOT:	/cvs/gcc
Module name:	gcc
Branch: 	gcc-3_4-branch
Changes by:	aoliva@gcc.gnu.org	2005-02-21 21:11:51

Modified files:
	gcc/cp         : ChangeLog class.c 
	gcc/testsuite  : ChangeLog 
Added files:
	gcc/testsuite/g++.dg/template: crash34.C 

Log message:
	gcc/cp/ChangeLog:
	PR c++/20028
	* class.c (finish_struct): Initialize TYPE_SIZE_UNIT of a
	template along with TYPE_SIZE.
	gcc/testsuite/ChangeLog:
	PR c++/20028
	* g++.dg/template/crash34.C: New.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=1.3892.2.200&r2=1.3892.2.201
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/class.c.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=1.595.4.9&r2=1.595.4.10
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=1.3389.2.363&r2=1.3389.2.364
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/g++.dg/template/crash34.C.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=NONE&r2=1.1.2.1



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20028

[Bug c++/20028] [3.4 Regression] class and then template class gives an ICE

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-02-21 21:34 -------
Fixed.

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20028