http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55305
Bug #: 55305
Summary: invalid aggregate constprop
Classification: Unclassified
Product: gcc
Version: 4.8.0
Status: UNCONFIRMED
Keywords: wrong-code
Severity: blocker
Priority: P3
Component: tree-optimization
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: i...@airs.com
When I compile and run this program with current mainline with -O0, -O1, or
-Og, it passes. When I use -O2, it crashes.
This is a reduced version of a failure in the libgo testsuite.
extern void exit (int) __attribute__ ((noreturn));
extern void abort (void) __attribute__ ((noreturn));
struct t
{
char dummy;
};
struct m
{
const struct t *t;
void (*m)(void);
};
struct s
{
const struct m *m;
void *o;
};
struct e
{
const struct t *t;
void *o;
};
struct ret
{
struct s s;
_Bool b;
};
const struct t t1 = { 1 };
const struct t t2 = { 2 };
const struct t t3 = { 3 };
const struct t t4 = { 4 };
const struct t t5 = { 5 };
void
pass (void)
{
exit (0);
}
void
fail (void)
{
abort ();
}
const struct m m1 = { &t4, fail };
const struct m m2 = { &t5, pass };
static struct e f2 (struct s s2, void *p);
static struct e f3 (struct s, void *) __attribute__ ((noinline));
static void f4 (struct s, void *) __attribute__ ((noinline));
struct ret c (struct s, const struct t *) __attribute__ ((noinline));
struct ret
c (struct s s1, const struct t *t)
{
struct ret r;
if (s1.m->t == t)
{
r.s.m = &m2;
r.s.o = s1.o;
r.b = 1;
}
else
{
r.s.m = 0;
r.s.o = 0;
r.b = 0;
}
return r;
}
void *m (void) __attribute__ ((noinline));
void *
m (void)
{
return 0;
}
struct e
f1 (struct s s1, void *p)
{
struct ret r;
void *a;
struct s a2;
r = c (s1, &t5);
if (r.b)
return f2 (r.s, p);
a = m ();
a2.m = &m1;
a2.o = a;
return f2 (a2, p);
}
static struct e
f2 (struct s s2, void *p)
{
struct e e1;
e1 = f3 (s2, p);
if (e1.t == &t2 && e1.o == 0)
{
e1.t = 0;
e1.o = 0;
}
return e1;
}
static struct e
f3 (struct s s1, void *p)
{
struct e r;
f4 (s1, p);
r.t = &t3;
r.o = 0;
return r;
}
struct s g1;
void *g2;
static void
f4 (struct s s1, void *p)
{
g1 = s1;
g2 = p;
s1.m->m ();
}
int
main ()
{
struct s s1;
s1.m = &m2;
s1.o = 0;
f1 (s1, 0);
abort ();
}
