[Bug c++/48446] New: internal compiler error: in gimplify_var_or_parm_decl, at gimplify.c:1946

[Bug c++/48446] New: internal compiler error: in gimplify_var_or_parm_decl, at gimplify.c:1946

[headch at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48446

           Summary: internal compiler error: in gimplify_var_or_parm_decl,
                    at gimplify.c:1946
           Product: gcc
           Version: 4.4.5
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: headch@gmail.com


Created attachment 23878
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=23878
The failing source file

I compile the attached file using this command:

$ g++ -std=gnu++0x -Wall -Wextra -c test.cpp

with this version of GCC:

$ gcc --version
gcc (Gentoo 4.4.5 p1.2, pie-0.4.5) 4.4.5
Copyright (C) 2010 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.

on Gentoo x86-64 and x86 (both produce identical error messages). I get this
output:

test.cpp: In member function ‘void Sender::flush()’:
test.cpp:168: internal compiler error: in gimplify_var_or_parm_decl, at
gimplify.c:1946
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://bugs.gentoo.org/> for instructions.

I also have access to an OpenSUSE x86-64 environment reading out this version:

$ gcc --version
gcc (SUSE Linux) 4.5.0 20100604 [gcc-4_5-branch revision 160292]
Copyright (C) 2010 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.

This gives the following output:

test.cpp: In member function ‘void Sender::flush()’:
test.cpp:175:71: internal compiler error: in gimplify_var_or_parm_decl, at
gimplify.c:1816
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://bugs.opensuse.org/> for instructions.

(yes, the source line number of the error in test.cpp is different for this GCC
version even though the sources are identical).

Finally, a friend using Arch Linux x86-64 tested the same code on GCC 4.6 and
also reproduced the bug, though I don't have the line numbers from that test.

I can attach preprocessed source if you want, though the source doesn't use
anything but standard headers and the problem seems quite easily reproducible
as I already described.

[Bug c++/48446] internal compiler error: in gimplify_var_or_parm_decl, at gimplify.c:1946

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48446

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |ice-on-valid-code
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2011.04.05 11:13:04
     Ever Confirmed|0                           |1
      Known to fail|                            |4.3.5, 4.5.2, 4.6.0

--- Comment #1 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-04-05 11:13:04 UTC ---
Confirmed.  Seems to have always crashed.  ICC accepts it.

Reduced testcase:

namespace std {
    typedef long unsigned int size_t;
}
typedef unsigned char uint8_t;
template<typename T> class RefPtr {
public:
    ~RefPtr();
    T *operator->() const;
};
class Message {
public:
    typedef RefPtr<Message> Ptr;
    static Ptr create(const void *data, std::size_t len);
};
template<std::size_t N> class BitArray {
public:
    static const std::size_t byte_count = (N + 7) / 8;
};
class Recipient {
public:
    typedef RefPtr<Recipient> Ptr;
    BitArray<80> data;
};
class Sender {
    Recipient::Ptr recipient(unsigned int i);
    void flush();
};
void Sender::flush()
{
    uint8_t buffer[64 / (recipient(0)->data.byte_count +
2)][recipient(0)->data.byte_count + 2];
    std::size_t wptr = 0;
    if (wptr == sizeof(buffer) / sizeof(*buffer)) {
        Message::Ptr msg = Message::create(buffer, wptr * sizeof(buffer[0]));
    }
}

[Bug c++/48446] internal compiler error: in gimplify_var_or_parm_decl, at gimplify.c:1946

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48446

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-04-05 11:21:35 UTC ---
slightly further reduced:

template<typename T> struct RefPtr {
        ~RefPtr();

        T *operator->() const;
};

struct Message  {
        typedef RefPtr<Message> Ptr;

        static Ptr create(int);
};


struct Recipient  {
        typedef RefPtr<Recipient> Ptr;

        static const int byte_count = 80;
};


Recipient::Ptr recipient();

void flush()
{
    char buffer[(recipient()->byte_count)];

    {
        Message::Ptr msg = Message::create(sizeof(buffer));
    }
}


This is a regression as it compiles OK with GCC 4.1

[Bug c++/48446] [4.3/4.4/4.5/4.6 Regression] internal compiler error: in gimplify_var_or_parm_decl, at gimplify.c:1946

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48446

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|                            |3.4.3

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-04-05 11:28:17 UTC ---
(In reply to comment #2)
> This is a regression as it compiles OK with GCC 4.1

... and 3.4

[Bug c++/48446] [4.3/4.4/4.5/4.6 Regression] internal compiler error: in gimplify_var_or_parm_decl, at gimplify.c:1946

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48446

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.3.6

[Bug c++/48446] [4.3/4.4/4.5/4.6 Regression] internal compiler error: in gimplify_var_or_parm_decl, at gimplify.c:1946

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48446

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu.org

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-04-07 08:30:57 UTC ---
template<typename T>
struct A
{
  ~A ();
  T *operator-> () const;
};

struct B
{
  typedef A <B> P;
  static P foo (int);
};

struct C
{
  typedef A<C> P;
  static const int c = 80;
};

C::P bar ();

void
baz ()
{
  char z[bar ()->c];
  {
    B::P m = B::foo (sizeof (z));
  }
}

Yeah, apparently some problem on the FE side with cleanups, where
CLEANUP_POINT_EXPR already for z is given the cleanups for m, which are in a
nested bind though and thus m wasn't seen in bind expr yet.

[Bug c++/48446] [4.3/4.4/4.5/4.6 Regression] internal compiler error: in gimplify_var_or_parm_decl, at gimplify.c:1946

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48446

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jason at gcc dot gnu.org

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-04-07 08:36:41 UTC ---
Most likely caused by
http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=128979
(r128750 works, r129000 ICEs, am lazy to bisect it exactly).

[Bug c++/48446] [4.3/4.4/4.5/4.6 Regression] internal compiler error: in gimplify_var_or_parm_decl, at gimplify.c:1946

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48446

--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-04-07 08:55:37 UTC ---
Actually now verified that it is r128979.

[Bug c++/48446] [4.3/4.4/4.5/4.6 Regression] internal compiler error: in gimplify_var_or_parm_decl, at gimplify.c:1946

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48446

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P2

[Bug c++/48446] [4.3/4.4/4.5/4.6 Regression] internal compiler error: in gimplify_var_or_parm_decl, at gimplify.c:1946

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48446

--- Comment #7 from Jason Merrill <jason at gcc dot gnu.org> 2011-04-14 15:00:03 UTC ---
Author: jason
Date: Thu Apr 14 14:59:58 2011
New Revision: 172432

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=172432
Log:
    PR c++/48446
    * decl.c (compute_array_index_type): Use get_temp_regvar instead
    of variable_size.
    * init.c (get_temp_regvar): No longer static.
    * cp-tree.h: Declare it.

Added:
    trunk/gcc/testsuite/g++.dg/ext/vla10.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/cp-tree.h
    trunk/gcc/cp/decl.c
    trunk/gcc/cp/init.c
    trunk/gcc/testsuite/ChangeLog

[Bug c++/48446] [4.3/4.4/4.5/4.6 Regression] internal compiler error: in gimplify_var_or_parm_decl, at gimplify.c:1946

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48446

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|                            |4.7.0

--- Comment #8 from Jason Merrill <jason at gcc dot gnu.org> 2011-04-14 15:22:41 UTC ---
This is now fixed for 4.7.0.  The fix seems reasonably safe to backport since
it only affects bounds expressions with side-effects, but it also seems easy to
work around in user code: just factor out the bounds expression into a local
variable.

[Bug c++/48446] [4.3/4.4/4.5/4.6 Regression] internal compiler error: in gimplify_var_or_parm_decl, at gimplify.c:1946

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48446

--- Comment #9 from Jason Merrill <jason at gcc dot gnu.org> 2011-05-02 18:38:49 UTC ---
Author: jason
Date: Mon May  2 18:38:44 2011
New Revision: 173264

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=173264
Log:
    PR c++/48446
    * decl.c (stabilize_save_expr_r, stabilize_vla_size): New.
    (compute_array_index_type): Revert earlier 48446 changes.
    (grokdeclarator): Use stabilize_vla_size.

Added:
    trunk/gcc/testsuite/c-c++-common/vla-1.c
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/decl.c
    trunk/gcc/testsuite/ChangeLog

[Bug c++/48446] [4.3/4.4/4.5/4.6 Regression] internal compiler error: in gimplify_var_or_parm_decl, at gimplify.c:1946

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48446

--- Comment #10 from Jason Merrill <jason at gcc dot gnu.org> 2011-05-06 21:58:32 UTC ---
Author: jason
Date: Fri May  6 21:58:30 2011
New Revision: 173514

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=173514
Log:
    PR c++/48446
    * decl.c (stabilize_save_expr_r, stabilize_vla_size): New.
    (grokdeclarator): Use stabilize_vla_size.
    * init.c (get_temp_regvar): No longer static.
    * cp-tree.h: Declare it.

Added:
    branches/gcc-4_6-branch/gcc/testsuite/c-c++-common/vla-1.c
    branches/gcc-4_6-branch/gcc/testsuite/g++.dg/ext/vla10.C
Modified:
    branches/gcc-4_6-branch/gcc/cp/ChangeLog
    branches/gcc-4_6-branch/gcc/cp/cp-tree.h
    branches/gcc-4_6-branch/gcc/cp/decl.c
    branches/gcc-4_6-branch/gcc/cp/init.c
    branches/gcc-4_6-branch/gcc/testsuite/ChangeLog

[Bug c++/48446] [4.3/4.4/4.5/4.6 Regression] internal compiler error: in gimplify_var_or_parm_decl, at gimplify.c:1946

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48446

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED
         AssignedTo|unassigned at gcc dot       |jason at gcc dot gnu.org
                   |gnu.org                     |
   Target Milestone|4.3.6                       |4.6.1

--- Comment #11 from Jason Merrill <jason at gcc dot gnu.org> 2011-05-07 01:41:03 UTC ---
Fixed for 4.6.1.