blob: ddd2c36cf1fb2e494cf78d147c6ba50e06f5fb6e (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
|
/* PR c/71924 - missing -Wreturn-local-addr returning alloca result
Test reduced from libstdc++-v3/testsuite/ext/ext_pointer/1.cc.
It verifies that iteration in find_implicit_erroneous_behavior
in gimple-ssa-isolate-path.c terminates under specific conditions.
{ dg-do compile }
{ dg-options "-O2 -Wall" } */
typedef __UINTPTR_TYPE__ uintptr_t;
struct A { int i; };
struct P { uintptr_t d; };
static inline struct A* get (const struct P *p)
{
if (p->d == 1)
return 0;
return (struct A*)((uintptr_t)p + p->d);
}
static inline void set (struct P *p, struct A* q)
{
/* The basic block below would cause an infinite loop in
find_implicit_erroneous_behavior due to assuming the DUPLICATE
pointer returned from isolate_path would distinct from the one
passed to it. (Replacing the if statement with the ternary ?:
expression did not have this effect (it gets optimized early
on).
<bb 4> [local count: 1073741823]:
# _14 = PHI <0B(2), &MEM <struct A[2]> [(void *)&a + 4B](3)>
_2 = _14->i;
if (_2 != 2)
goto <bb 5>; [0.00%]
else
goto <bb 6>; [100.00%]
*/
if (!q)
p->d = 1;
else
p->d = (uintptr_t)(q) - (uintptr_t)(p);
}
void f (void)
{
struct A a[2] = { { 1 }, { 2 } };
struct P p, q;
set (&p, a);
set (&q, get (&p));
set (&q, get (&q) + 0);
set (&q, get (&q) + 1);
if (get (&q)[0].i != get (&p)[1].i)
__builtin_abort ();
}
|
