[Bug c/53163] New: crash due to null ptr deref

["regehr at cs dot utah.edu" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53163

             Bug #: 53163
           Summary: crash due to null ptr deref
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: regehr@cs.utah.edu
                CC: chenyang@cs.utah.edu


[regehr@dyson r43]$ current-gcc -c -O3 small.c
small.c: In function 'fn2':
small.c:22:1: internal compiler error: Segmentation fault
 fn2 ()
 ^
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.
[regehr@dyson r43]$ cat small.c
struct
{
    int f0;
} b, f;
int a, c;
void
fn1 ()
{
    int d, e;
    d = 4;
    for (; d < 19; ++d)
    {
        e = 2;
        for (; e >= 0; e--)
        {
            a = 0;
            a = 1;
        }
    }
}
void
fn2 ()
{
    int g, h, i;
    i = 1;
    for (; i >= 0; i--)
    {
        b = f;
        g = 0;
        for (; g <= 1; g++)
        {
            if (c)
                break;
            h = 0;
            for (; h <= 1; h++)
                fn1 ();
            fn1 ();
        }
    }
}
[regehr@dyson r43]$ current-gcc -v
Using built-in specs.
COLLECT_GCC=current-gcc
COLLECT_LTO_WRAPPER=/uusoc/exports/scratch/regehr/z/compiler-install/gcc-r186946-install/bin/../libexec/gcc/x86_64-unknown-linux-gnu/4.8.0/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: ../configure --with-libelf=/usr/local --enable-lto
--prefix=/home/regehr/z/compiler-install/gcc-r186946-install
--program-prefix=r186946- --enable-languages=c,c++
Thread model: posix
gcc version 4.8.0 20120429 (experimental) (GCC)