[Bug c++/59268] New: [4.7/4.8/4.9 Regression] [c++11] ICE with constexpr in a virtual function

[Bug c++/59268] New: [4.7/4.8/4.9 Regression] [c++11] ICE with constexpr in a virtual function

[reichelt at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59268

            Bug ID: 59268
           Summary: [4.7/4.8/4.9 Regression] [c++11] ICE with constexpr in
                    a virtual function
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: reichelt at gcc dot gnu.org

The following valid code snippet (compiled with "-std=c++11" or "-std=c++0x"
for older compilers) triggers an ICE since GCC 4.6.1:

===================================
template<typename> struct A
{
  constexpr A(int) {}

  virtual void foo()
  {
    constexpr A<void> a(0);
  }
};
===================================

bug.cc: In instantiation of 'void A< <template-parameter-1-1> >::foo() [with
<template-parameter-1-1> = void]':
bug.cc:14:2:   required from here
bug.cc:12:26: internal compiler error: in tsubst_copy, at cp/pt.c:12862
     constexpr A<void> a(0);
                          ^
0x5de3f3 tsubst_copy
        ../../gcc/gcc/cp/pt.c:12862
0x5bba96 tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool,
bool)
        ../../gcc/gcc/cp/pt.c:15071
0x5bcde6 tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool,
bool)
        ../../gcc/gcc/cp/pt.c:14873
0x5c5ab7 tsubst_expr
        ../../gcc/gcc/cp/pt.c:13776
0x5c6d7b tsubst_expr
        ../../gcc/gcc/cp/pt.c:13298
0x5c571e tsubst_expr
        ../../gcc/gcc/cp/pt.c:13395
0x5c271c instantiate_decl(tree_node*, int, bool)
        ../../gcc/gcc/cp/pt.c:19641
0x601167 instantiate_pending_templates(int)
        ../../gcc/gcc/cp/pt.c:19753
0x63c933 cp_write_global_declarations()
        ../../gcc/gcc/cp/decl2.c:4131
Please submit a full bug report, [etc.]

[Bug c++/59268] [4.7/4.8/4.9 Regression] [c++11] ICE with constexpr in a virtual function

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59268

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P2
   Target Milestone|---                         |4.7.4

[Bug c++/59268] [4.7/4.8/4.9 Regression] [c++11] ICE with constexpr in a virtual function

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59268

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2013-12-03
           Assignee|unassigned at gcc dot gnu.org      |jakub at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 31364
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=31364&action=edit
gcc49-pr59268.patch

Untested fix.

[Bug c++/59268] [4.7/4.8/4.9 Regression] [c++11] ICE with constexpr in a virtual function

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59268

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Author: jakub
Date: Wed Dec  4 18:14:01 2013
New Revision: 205675

URL: http://gcc.gnu.org/viewcvs?rev=205675&root=gcc&view=rev
Log:
    PR c++/59268
    * pt.c (tsubst_copy_and_build): Handle POINTER_PLUS_EXPR.

    * g++.dg/cpp0x/constexpr-template6.C: New test.

Added:
    branches/gcc-4_8-branch/gcc/testsuite/g++.dg/cpp0x/constexpr-template6.C
Modified:
    branches/gcc-4_8-branch/gcc/cp/ChangeLog
    branches/gcc-4_8-branch/gcc/cp/pt.c
    branches/gcc-4_8-branch/gcc/testsuite/ChangeLog

[Bug c++/59268] [4.7/4.8/4.9 Regression] [c++11] ICE with constexpr in a virtual function

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59268

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

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

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Fixed for 4.8.3+, though with --enable-checking=release it doesn't ICE and just
works (because then tsubst_copy just passes it through unmodified, which is
sufficient here).
So IMHO not work doing anything for 4.7.x.