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Commit | Line | Data |
---|---|---|
0cd3301b | 1 | /* { dg-do run } */ |
895b56ff | 2 | |
61f5be15 GM |
3 | /* Testcase distilled from glibc's nss_parse_service_list in nss/nsswitch.c |
4 | It can't be distilled further. Fails with `-O2' for i[3456]86. */ | |
5 | ||
6 | /* this simulates a bounded-pointer type. */ | |
7 | struct ucharp { unsigned char *v, *l, *h; }; | |
8 | ||
9 | /* this simulates bounded-pointer check prior to pointer dereference. */ | |
10 | #define AREF(var, idx) ((((((((var).v+(idx)) < (var).l) \ | |
11 | || (((var).v+(idx)+1) > (var).h))) \ | |
12 | && (__builtin_trap (), 0)), \ | |
13 | (var).v)[(idx)]) | |
14 | ||
15 | struct list | |
16 | { | |
17 | struct list *next; | |
18 | }; | |
19 | ||
20 | struct list * | |
21 | alloc_list (void) | |
22 | { | |
23 | static struct list l; | |
24 | return &l; | |
25 | } | |
26 | ||
27 | int one = 1; | |
28 | ||
29 | void | |
30 | foo (struct ucharp cp, struct ucharp lp, struct list **nextp) | |
31 | { | |
32 | while (1) | |
33 | { | |
34 | struct list *list; | |
35 | while (AREF (lp, 0) && AREF (cp, AREF (lp, 0))) | |
36 | ++lp.v; | |
37 | list = alloc_list (); | |
38 | while (AREF (cp, AREF (lp, 0))) | |
39 | ++lp.v; | |
40 | if (AREF (lp, 0) == one) | |
41 | do | |
42 | ++lp.v; | |
43 | while (AREF (lp, 0) && AREF (cp, AREF (lp, 0))); | |
44 | /* The above AREF (cp, ...) fails because the pseudo created to | |
45 | hold cp.v holds garbage, having never been set. | |
46 | The easiest way to see the problem is to compile wiht `-O2 -da' | |
47 | then look at *.09.loop. Search for something like this: | |
48 | ||
49 | Hoisted regno 183 r/o from (mem/s:SI (reg:SI 16 argp) 10) | |
50 | Replaced reg 91, deleting init_insn (213). | |
51 | ||
52 | Now, look for the use of reg 91, which has no set. */ | |
53 | ||
54 | *nextp = list; | |
55 | nextp = &list->next; | |
56 | if (!*lp.v) | |
57 | break; | |
58 | } | |
59 | } | |
60 | ||
61 | extern void exit (int); | |
62 | ||
63 | int | |
64 | main (void) | |
65 | { | |
66 | static unsigned char cp0[] = "\0\0\0\0"; | |
67 | struct ucharp cp = { cp0, cp0, cp0 + sizeof (cp0) }; | |
68 | ||
69 | static unsigned char lp0[] = "\1\1\0\0"; | |
70 | struct ucharp lp = { lp0, lp0, lp0 + sizeof (lp0) }; | |
71 | ||
72 | struct list list; | |
73 | struct list *nextp = &list; | |
74 | ||
75 | foo (cp, lp, &nextp); | |
76 | ||
77 | exit (0); | |
78 | } |