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1 | /* Test program to trigger mcount overflow in profiling collection. |
2 | Copyright (C) 2017-2023 Free Software Foundation, Inc. | |
3 | This file is part of the GNU C Library. | |
4 | ||
5 | The GNU C Library is free software; you can redistribute it and/or | |
6 | modify it under the terms of the GNU Lesser General Public | |
7 | License as published by the Free Software Foundation; either | |
8 | version 2.1 of the License, or (at your option) any later version. | |
9 | ||
10 | The GNU C Library is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | Lesser General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU Lesser General Public | |
16 | License along with the GNU C Library; if not, see | |
17 | <https://www.gnu.org/licenses/>. */ | |
18 | ||
19 | /* Program with sufficiently complex, yet pointless, call graph | |
20 | that it will trigger an mcount overflow, when you set the | |
21 | minarcs/maxarcs tunables to very low values. */ | |
22 | ||
23 | #define PREVENT_TAIL_CALL asm volatile ("") | |
24 | ||
25 | /* Calls REP(n) macro 16 times, for n=0..15. | |
26 | * You need to define REP(n) before using this. | |
27 | */ | |
28 | #define REPS \ | |
29 | REP(0) REP(1) REP(2) REP(3) REP(4) REP(5) REP(6) REP(7) \ | |
30 | REP(8) REP(9) REP(10) REP(11) REP(12) REP(13) REP(14) REP(15) | |
31 | ||
32 | /* Defines 16 leaf functions named f1_0 to f1_15 */ | |
33 | #define REP(n) \ | |
34 | __attribute__ ((noinline, noclone, weak)) void f1_##n (void) {}; | |
35 | REPS | |
36 | #undef REP | |
37 | ||
38 | /* Calls all 16 leaf functions f1_* in succession */ | |
39 | __attribute__ ((noinline, noclone, weak)) void | |
40 | f2 (void) | |
41 | { | |
42 | # define REP(n) f1_##n(); | |
43 | REPS | |
44 | # undef REP | |
45 | PREVENT_TAIL_CALL; | |
46 | } | |
47 | ||
48 | /* Defines 16 functions named f2_0 to f2_15, which all just call f2 */ | |
49 | #define REP(n) \ | |
50 | __attribute__ ((noinline, noclone, weak)) void \ | |
51 | f2_##n (void) { f2(); PREVENT_TAIL_CALL; }; | |
52 | REPS | |
53 | #undef REP | |
54 | ||
55 | __attribute__ ((noinline, noclone, weak)) void | |
56 | f3 (int count) | |
57 | { | |
58 | for (int i = 0; i < count; ++i) | |
59 | { | |
60 | /* Calls f1_0(), f2_0(), f1_1(), f2_1(), f3_0(), etc */ | |
61 | # define REP(n) f1_##n(); f2_##n(); | |
62 | REPS | |
63 | # undef REP | |
64 | } | |
65 | } | |
66 | ||
67 | int | |
68 | main (void) | |
69 | { | |
70 | f3 (1000); | |
71 | return 0; | |
72 | } |