[Bug c++/43368] New: different access to templated structure static field give different results

[Bug c++/43368] New: different access to templated structure static field give different results

[pogonyshev at gmx dot net]

Tested with Debian testing 4.4.3-3 and 4.3.4-8.

Compiling this code snippet:

template <int& field>
struct Foo
{
  static  int
  bar ()
  {  return field;  }
};

template <bool>
struct X
{
  static  int  x;
  typedef  Foo <x>  foo;
};

// This makes first statement in main() compile, but not the second...
template <>
int  X <false>::x = 0;

int
main ()
{
  X <false>::x;
  X <false>::foo::bar ();
}

with 'g++ test.cpp -o test' gives the following error on linking stage:

/tmp/ccuo8N2e.o: In function `_ZN3FooILZN1XIXT_EE1xEEE3barEv':
test.cpp:(.text._ZN3FooILZN1XIXT_EE1xEEE3barEv[_ZN3FooILZN1XIXT_EE1xEEE3barEv]+0x4):
undefined reference to `_ZN1XIXT_EE1xE'

This is a regression: it works with 4.1, but doesn't with 4.3 or 4.4.  Didn't
test 4.2.


-- 
           Summary: different access to templated structure static field
                    give different results
           Product: gcc
           Version: 4.4.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: pogonyshev at gmx dot net
 GCC build triplet: i486-pc-linux-gnu
  GCC host triplet: i486-pc-linux-gnu
GCC target triplet: i486-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43368

[Bug c++/43368] [4.3/4.4/4.5 Regression] different access to templated structure static field give different results

[hjl dot tools at gmail dot com]

------- Comment #1 from hjl dot tools at gmail dot com  2010-03-14 23:27 -------
It is caused by revision 131044:

http://gcc.gnu.org/ml/gcc-cvs/2007-12/msg00495.html


-- 

hjl dot tools at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jason at redhat dot com
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2010-03-14 23:27:09
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43368

[Bug c++/43368] [4.3/4.4/4.5 Regression] different access to templated structure static field give different results

[redi at gcc dot gnu dot org]

------- Comment #2 from redi at gcc dot gnu dot org  2010-03-15 10:32 -------
Is this valid?
The 'foo' typedef needs the address of X::x but occurs before it has been
defined.

Comeau gives
line 18: error: explicit specialization of member
          "X<<unnamed>>::x [with <unnamed>=false]" must precede its first use (
          at line 13)


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43368

[Bug c++/43368] [4.3/4.4/4.5 Regression] different access to templated structure static field give different results

[rguenth at gcc dot gnu dot org]

------- Comment #3 from rguenth at gcc dot gnu dot org  2010-03-15 11:20 -------
EDG agrees.  But accepts the code without the explicit specialization.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.3.5


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43368

[Bug c++/43368] [4.3/4.4/4.5 Regression] different access to templated structure static field give different results

[redi at gcc dot gnu dot org]

------- Comment #4 from redi at gcc dot gnu dot org  2010-03-15 12:22 -------
14.7.3 [temp.expl.spec] p6 says:

If a template, a member template or the member of a class template is
explicitly specialized then that specialization
shall be declared before the first use of that specialization that would cause
an implicit instantiation
to take place, in every translation unit in which such a use occurs; no
diagnostic is required.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43368

[Bug c++/43368] different access to templated structure static field give different results

[rguenth at gcc dot gnu dot org]

------- Comment #5 from rguenth at gcc dot gnu dot org  2010-03-15 13:20 -------
Not a regression.  Diagnostic enhancement possible.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |enhancement
           Keywords|                            |accepts-invalid, diagnostic
            Summary|[4.3/4.4/4.5 Regression]    |different access to
                   |different access to         |templated structure static
                   |templated structure static  |field give different results
                   |field give different results|
   Target Milestone|4.3.5                       |---


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43368

[Bug c++/43368] different access to templated structure static field give different results

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=43368

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
      Known to fail|                            |
         Resolution|---                         |DUPLICATE

--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
This is a dup of bug 22354.

*** This bug has been marked as a duplicate of bug 22354 ***