[Bug c++/54485] New: g++ should diagnose default arguments in out-of-line definitions for template class member functions

[Bug c++/54485] New: g++ should diagnose default arguments in out-of-line definitions for template class member functions

[dnovillo at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54485

             Bug #: 54485
           Summary: g++ should diagnose default arguments in out-of-line
                    definitions for template class member functions
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Keywords: accepts-invalid
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: dnovillo@gcc.gnu.org
                CC: jason@gcc.gnu.org


In PR 54484, bootstraps were broken with clang++.  The template class vec_t had
a member function with default arguments, but the default values were specified
in the function definition, instead of its declaration.

According to 8.3.6, that's incorrect: "Default arguments for a member function
of a class template shall be specified on the initial declaration of the member
function within the class template."

$ cat a.cc
template<typename T>
class K
{
  int fn(int, int);
};

template<typename T>
int K<T>::fn (int a, int b = 3)
{
  return a - b;
}

$ g++ -c a.cc

$ clang++ -c a.cc
a.cc:8:26: error: default arguments cannot be added to an out-of-line
definition      of a member of a class template
int K<T>::fn (int a, int b = 3)
                         ^   ~
1 error generated.

$ g++ --version
g++ (Ubuntu/Linaro 4.6.3-1ubuntu5) 4.6.3
Copyright (C) 2011 Free Software Foundation, Inc.This is free software; see the
source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

$ clang++ --version
Ubuntu clang version 3.0-6ubuntu3 (tags/RELEASE_30/final) (based on LLVM
3.0)Target: x86_64-pc-linux-gnu
Thread model: posix

[Bug c++/54485] g++ should diagnose default arguments in out-of-line definitions for template class member functions

[thiago at kde dot org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54485

Thiago Macieira <thiago at kde dot org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |thiago at kde dot org

--- Comment #1 from Thiago Macieira <thiago at kde dot org> 2012-09-05 07:27:08 UTC ---
FYI

$ icpc -c a.cc

[Bug c++/54485] g++ should diagnose default arguments in out-of-line definitions for template class member functions

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54485

Richard Guenther <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2012-09-05
     Ever Confirmed|0                           |1

--- Comment #2 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-09-05 09:20:27 UTC ---
Confirmed.  Probably worth accepting with -fpermissive?

[Bug c++/54485] g++ should diagnose default arguments in out-of-line definitions for template class member functions

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54485

--- Comment #4 from Paolo Carlini <paolo.carlini at oracle dot com> ---
Patch here: http://gcc.gnu.org/ml/gcc-patches/2013-08/msg01435.html

[Bug c++/54485] g++ should diagnose default arguments in out-of-line definitions for template class member functions

[paolo at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54485

--- Comment #5 from paolo at gcc dot gnu.org <paolo at gcc dot gnu.org> ---
Author: paolo
Date: Mon Nov 25 22:24:58 2013
New Revision: 205367

URL: http://gcc.gnu.org/viewcvs?rev=205367&root=gcc&view=rev
Log:
/cp
2013-11-25  Paolo Carlini  <paolo.carlini@oracle.com>

    PR c++/54485
    * decl.c (duplicate_decls): Enforce 8.3.6/6 about default arguments
    for member functions of class templates.

/testsuite
2013-11-25  Paolo Carlini  <paolo.carlini@oracle.com>

    PR c++/54485
    * g++.dg/other/default8.C: New.
    * g++.dg/tc1/dr217.C: Remove xfail.
    * g++.dg/other/default5.C: Adjust.
    * g++.old-deja/g++.mike/p1989.C: Likewise.

Added:
    trunk/gcc/testsuite/g++.dg/other/default8.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/decl.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/g++.dg/other/default5.C
    trunk/gcc/testsuite/g++.dg/tc1/dr217.C
    trunk/gcc/testsuite/g++.old-deja/g++.mike/p1989.C

[Bug c++/54485] g++ should diagnose default arguments in out-of-line definitions for template class member functions

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54485

Paolo Carlini <paolo.carlini at oracle dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED
           Assignee|paolo.carlini at oracle dot com    |unassigned at gcc dot gnu.org

--- Comment #6 from Paolo Carlini <paolo.carlini at oracle dot com> ---
Fixed for 4.9.0.