[Bug c++/50361] New: gcc 4.6 ICE probably relating to std::initializer_list and template argument deduction

[Bug c++/50361] New: gcc 4.6 ICE probably relating to std::initializer_list and template argument deduction

[delong.j at fb dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50361

             Bug #: 50361
           Summary: gcc 4.6 ICE probably relating to std::initializer_list
                    and template argument deduction
    Classification: Unclassified
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: major
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: delong.j@fb.com


Created attachment 25243
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=25243
preprocessed source output

Error is:

gcc_test/test.cpp: In function ‘int main()’:
gcc_test/test.cpp:67: 1: internal compiler error: in fold_convert_loc, at
fold-const.c:2028
Please submit a full bug report,
with preprocessed source if appropriate.

I was running into this in a fairly convoluted case, but pulled parts of it out
until I had a fairly minimal repro.

A hint here appears to be that if you define the constructors inside the class
instead of outside the class the ICE goes away.  Also removing the union member
removes the ICE.

[Bug c++/50361] gcc 4.6 ICE probably relating to std::initializer_list and template argument deduction

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50361

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-09-12 07:47:28 UTC ---
seems to be fixed on the 4.6 branch, but 4.7 gives a different ICE:
gcc_test/test.cpp:69:64: internal compiler error: in count_type_elements, at
expr.c:5310

[Bug c++/50361] [C++0x] ICE probably relating to std::initializer_list and template argument deduction

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50361

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|gcc 4.6 ICE probably        |[C++0x] ICE probably
                   |relating to                 |relating to
                   |std::initializer_list and   |std::initializer_list and
                   |template argument deduction |template argument deduction
           Severity|major                       |normal

--- Comment #2 from Paolo Carlini <paolo.carlini at oracle dot com> 2011-09-12 10:59:54 UTC ---
Can you please try reducing it further? 402.1 KB is still unmanageable (Note:
I'm adding the C++0x marker, I suppose you are using -std=c++0x or
-std=gnu++0x, the info about the command line is missing)

[Bug c++/50361] [C++0x] [4.7 Regression] ICE probably relating to std::initializer_list and template argument deduction

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50361

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2011-09-12
                 CC|delong.j at fb dot com      |jason at gcc dot gnu.org
            Summary|[C++0x] ICE probably        |[C++0x] [4.7 Regression]
                   |relating to                 |ICE probably relating to
                   |std::initializer_list and   |std::initializer_list and
                   |template argument deduction |template argument deduction
     Ever Confirmed|0                           |1

--- Comment #3 from Paolo Carlini <paolo.carlini at oracle dot com> 2011-09-12 11:50:33 UTC ---
Confirmed the mainline ICE.

[Bug c++/50361] [C++0x] [4.7 Regression] ICE with std::initializer_list nullptr

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50361

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[C++0x] [4.7 Regression]    |[C++0x] [4.7 Regression]
                   |ICE probably relating to    |ICE with
                   |std::initializer_list and   |std::initializer_list
                   |template argument deduction |nullptr

--- Comment #4 from Paolo Carlini <paolo.carlini at oracle dot com> 2011-09-12 12:08:20 UTC ---
This is enough:

#include <initializer_list>

struct Foo
{
  Foo(std::initializer_list<Foo>) { };

  template<class T> Foo(T t) { T u(t); };

private:
  union Data
  {
    Data() : null(nullptr) {}

    std::nullptr_t null;
  } u_;
};

int main()
{
  Foo f = { {} };
}

[Bug c++/50361] [C++0x] [4.7 Regression] ICE with std::initializer_list and nullptr

[delong.j at fb dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50361

--- Comment #5 from Jordan DeLong <delong.j at fb dot com> 2011-09-12 19:38:22 UTC ---
Ah, thanks Paolo.  That simplification also gave me enough hints for a
work-around for now.

[Bug c++/50361] [C++0x] [4.7 Regression] ICE with std::initializer_list and nullptr

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50361

Jason Merrill <jason at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
         AssignedTo|unassigned at gcc dot       |jason at gcc dot gnu.org
                   |gnu.org                     |

[Bug c++/50361] [C++0x] [4.7 Regression] ICE with std::initializer_list and nullptr

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50361

--- Comment #6 from Jason Merrill <jason at gcc dot gnu.org> 2011-09-15 14:33:29 UTC ---
Author: jason
Date: Thu Sep 15 14:33:24 2011
New Revision: 178882

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=178882
Log:
    PR c++/50361
    * expr.c (count_type_elements): Handle NULLPTR_TYPE.

Added:
    trunk/gcc/testsuite/g++.dg/cpp0x/nullptr23.C
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/expr.c
    trunk/gcc/testsuite/ChangeLog

[Bug c++/50361] [C++0x] [4.7 Regression] ICE with std::initializer_list and nullptr

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50361

Jason Merrill <jason at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.7.0

--- Comment #7 from Jason Merrill <jason at gcc dot gnu.org> 2011-09-15 14:34:21 UTC ---
Fixed.

[Bug c++/50361] [C++0x] [4.7 Regression] ICE with std::initializer_list and nullptr

[delong.j at fb dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50361

--- Comment #8 from Jordan DeLong <delong.j at fb dot com> 2011-09-16 20:12:43 UTC ---
Thanks!