[Bug c++/16635] New: g++ doesn't diagnose instantiation of template that uses incomplete type

[Bug c++/16635] New: g++ doesn't diagnose instantiation of template that uses incomplete type

[geoffk at gcc dot gnu dot org]

Consider the following:

template <class T> T * foo (T * x)
{ 
  return x++;
}

struct aclass;

aclass *
addone (aclass * x)
{ 
  return foo<aclass>(x);
}

struct aclass
{ 
  int x;
};

At the point where foo<aclass> is instantiated, 'aclass' is incomplete, and 'x++' requires it to be 
complete, so this program is not well-formed, and a diagnostic is required.

-- 
           Summary: g++ doesn't diagnose instantiation of template that uses
                    incomplete type
           Product: gcc
           Version: 3.5.0
            Status: UNCONFIRMED
          Keywords: accepts-invalid
          Severity: normal
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: geoffk at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org
  GCC host triplet: powerpc-apple-darwin7.3
GCC target triplet: powerpc-apple-darwin7.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16635

[Bug c++/16635] g++ doesn't diagnose instantiation of template that uses incomplete type

[bangerth at dealii dot org]

------- Additional Comments From bangerth at dealii dot org  2004-07-19 20:23 -------
Confirmed. I'm sure Giovanni has something to say about this. 
 
W. 

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |giovannibajo at gcc dot gnu
                   |                            |dot org
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2004-07-19 20:23:19
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16635

[Bug c++/16635] g++ doesn't diagnose instantiation of template that uses incomplete type

[giovannibajo at libero dot it]

------- Additional Comments From giovannibajo at libero dot it  2004-07-31 00:25 -------
I am not 100% sure about this. Geoff, why do you think GCC is wrong? FWIW EDG 
does exactly the same. Do you have a specific quote from the standard?

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16635

[Bug c++/16635] g++ instantiates templates at the wrong place

[geoffk at gcc dot gnu dot org]

------- Additional Comments From geoffk at gcc dot gnu dot org  2005-04-26 06:53 -------
Here's the same thing with overloaded functions, causing a wrong-code error.  If the last definition of 
'bar' is commented out, the testcase passes, but otherwise not.

template <class T> int func(T & x)
{
  return bar (x);
}

int bar(const int & x)
{
  return x;
}

extern "C" void abort ();

int main (void)
{
  int x = 3;
  if (func<int>(x) != 3)
    abort ();
}

int bar (int &x)
{
  return x + 3;
}


-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |wrong-code
      Known to fail|                            |3.3 4.0.0
            Summary|g++ doesn't diagnose        |g++ instantiates templates
                   |instantiation of template   |at the wrong place
                   |that uses incomplete type   |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16635

[Bug c++/16635] g++ instantiates templates at the wrong place

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-06-23 01:19 -------
(In reply to comment #5)
> Here's the same thing with overloaded functions, causing a wrong-code error.  If the last definition of 
> 'bar' is commented out, the testcase passes, but otherwise not.
That code is acutally invalid and really should have been rejected see PR 2922 for that.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|wrong-code                  |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16635

[Bug c++/16635] g++ instantiates templates at the wrong place

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-06-23 01:27 -------
(In reply to comment #6)
> (In reply to comment #5)
> > Here's the same thing with overloaded functions, causing a wrong-code error.  If the last definition 
of 
> > 'bar' is commented out, the testcase passes, but otherwise not.
> That code is acutally invalid and really should have been rejected see PR 2922 for that.

Also if we move the template func after bar and main after the second bar, we get back to basicially PR 
2922.  So the first testcase is the only one which the problem for this bug.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16635