[Bug c++/57793] [4.7/4.8/4.9 Regression] ICE wiith bitfields in get_bit_range

[Bug c++/57793] [4.7/4.8/4.9 Regression] ICE wiith bitfields in get_bit_range

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57793

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2013-07-03
            Summary|Cross-Compiler Templates    |[4.7/4.8/4.9 Regression]
                   |and Bitfields Ask to Report |ICE wiith bitfields in
                   |Problem                     |get_bit_range
     Ever confirmed|0                           |1

--- Comment #1 from Paolo Carlini <paolo.carlini at oracle dot com> ---
I can confirm this on x86_64-linux -m32, no need for a cross-compiler. I doubt
however that it's a C++ front-end issue.

[Bug c++/57793] [4.7/4.8/4.9 Regression] ICE with bitfields in get_bit_range

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57793

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|ice-on-valid-code           |ice-on-invalid-code
                 CC|                            |jakub at gcc dot gnu.org

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Reduced testcase:
struct A { bool a : 1; bool b : 1; };
struct B
{
  unsigned char c[0x40000000];
  unsigned char d[0x40000ff0];
  A e;
  void *foo ()
  {
    if (e.a)
      return (void *) 0;
    e.b = true;
    return c;
  }
};
void
bar (B *p)
{
  p->foo ();
}

This is of course invalid for 32-bit arches, you can't have an aggregate larger
than half of the address space, so this PR is just about missing diagnostics
for it.  If the single field is 0x80000000U bytes or larger, gcc already
diagnoses it.

[Bug c++/57793] [4.7/4.8/4.9 Regression] ICE with bitfields in get_bit_range

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57793

--- Comment #4 from Paolo Carlini <paolo.carlini at oracle dot com> ---
Thanks Jakub.

[Bug c++/57793] [4.7/4.8/4.9 Regression] ICE with bitfields in get_bit_range

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57793

--- Comment #5 from Paolo Carlini <paolo.carlini at oracle dot com> ---
Note that something like this ICEs the C compiler too:

struct A { _Bool a : 1; _Bool b : 1; };
struct B
{
  unsigned char c[0x40000000];
  unsigned char d[0x40000ff0];
  struct A e;
};

void *foo (struct B *p)
{
  if (p->e.a)
    return (void *) 0;
  p->e.b = 1;
  return p->c;
}

void
bar (struct B *p)
{
  foo (p);
}

thus I wonder if the check belongs to the front-end(s) or not. Opinions?

[Bug c++/57793] [4.7/4.8/4.9 Regression] ICE with bitfields in get_bit_range

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57793

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
                 CC|jason at gcc dot gnu.org           |
         Resolution|---                         |FIXED
   Target Milestone|---                         |4.9.0

--- Comment #6 from Paolo Carlini <paolo.carlini at oracle dot com> ---
Thus this is fixed for 4.9.0.