[Bug c++/37553] New: ICE in build_c_cast

[Bug c++/37553] New: ICE in build_c_cast

[patrakov at gmail dot com]

This code triggers an ICE in gcc-4.3.1 on i686 when compiled with g++:

typedef unsigned int ui32;
__extension__ typedef unsigned long long int ui64;

typedef ui32 __attribute__ ((__may_alias__)) ui32a;
typedef ui64 __attribute__ ((__may_alias__)) ui64a;

union u_u32
{
  ui32a v;
} __attribute__ ((__may_alias__));

union u_u64
{
  ui64a v;
  struct
  {
    union u_u32 lo32, hi32;
  } u;
} __attribute__ ((__may_alias__));

void
out_long (ui64 longVal)
{
  if ((*(union u_u64 *) &longVal).u.lo32.v < 0x10000000ul)
    {
      if ((ui32) ((*(union u_u64 *) &longVal).u.lo32.v) < 0x4000u)
        {
          /* do something useful */
        }
    }
}

longs3.c: In function 'void out_long(ui64)':
longs3.c:24: internal compiler error: in build_c_cast, at cp/typeck.c:5631


-- 
           Summary: ICE in build_c_cast
           Product: gcc
           Version: 4.3.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: patrakov at gmail dot com
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37553

[Bug c++/37553] [4.3/4.4 Regression] ICE in build_c_cast

[pinskia at gcc dot gnu dot org]

------- Comment #1 from pinskia at gcc dot gnu dot org  2008-09-17 21:02 -------
I get a different internal compiler error:
t.cc:24: internal compiler error: canonical types differ for identical types
ui32 and ui32a
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
           Keywords|                            |ice-on-valid-code
   Last reconfirmed|0000-00-00 00:00:00         |2008-09-17 21:02:56
               date|                            |
            Summary|ICE in build_c_cast         |[4.3/4.4 Regression] ICE in
                   |                            |build_c_cast
   Target Milestone|---                         |4.3.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37553

[Bug c++/37553] [4.3/4.4 Regression] ICE in build_c_cast

[rguenth at gcc dot gnu dot org]

------- Comment #2 from rguenth at gcc dot gnu dot org  2008-09-20 14:49 -------
ui32 and ui32a are identical (they are identical in middle-end terms), but
ui32 * and ui32a * would not be identical.  Sounds weird, but the way
may_alias is designed make it so.  A 32bit target is required to trigger
the ICE.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|                            |4.2.4
           Priority|P3                          |P2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37553

[Bug c++/37553] [4.3/4.4 Regression] ICE in build_c_cast

[doug dot gregor at gmail dot com]

-- 

doug dot gregor at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |doug dot gregor at gmail dot
                   |dot org                     |com
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2008-09-17 21:02:56         |2008-09-24 04:37:04
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37553

[Bug c++/37553] [4.3/4.4 Regression] ICE in build_c_cast

[doug dot gregor at gmail dot com]

------- Comment #3 from doug dot gregor at gmail dot com  2008-09-24 06:01 -------
Patch here: http://gcc.gnu.org/ml/gcc-patches/2008-09/msg01667.html


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37553

[Bug c++/37553] [4.3/4.4 Regression] ICE in build_c_cast

[dgregor at gcc dot gnu dot org]

------- Comment #4 from dgregor at gcc dot gnu dot org  2008-10-14 15:05 -------
Subject: Bug 37553

Author: dgregor
Date: Tue Oct 14 15:03:51 2008
New Revision: 141111

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=141111
Log:
2008-10-14  Douglas Gregor  <doug.gregor@gmail.com>

       PR c++/37553
       * tree.c (build_type_attribute_qual_variant): Hash on the
       unqualified type, and don't overwrite an existing
       (type_hash_eq): Make the TYPE_NAME of the types significant, to
       allow distinguishing between wchar_t and its underlying type. This
       also means that we'll retain a little more typedef information.

2008-10-14  Douglas Gregor  <doug.gregor@gmail.com>

       PR c++/37553
       * g++.dg/ext/alias-canon2.C: New.

Added:
    trunk/gcc/testsuite/g++.dg/ext/alias-canon2.C
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37553

[Bug c++/37553] [4.3/4.4 Regression] ICE in build_c_cast

[doug dot gregor at gmail dot com]

------- Comment #5 from doug dot gregor at gmail dot com  2008-10-14 16:03 -------
Fixed on mainline


-- 

doug dot gregor at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|4.3.3                       |4.4.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37553