1// RUN: %clang_tysan -O0 %s -o %t && %run %t >%t.out 2>&1
2// RUN: FileCheck %s < %t.out
3
4// https://github.com/llvm/llvm-project/issues/47137
5#include <stdint.h>
6#include <stdio.h>
7#include <stdlib.h>
8
9void f(int m) {
10 int n = (4 * m + 2) / 3;
11 uint64_t *a = malloc(size: n * sizeof(uint64_t));
12 uint64_t *b = malloc(size: n * sizeof(uint64_t));
13 uint64_t aa[] = {0xffff3e0000000001, 0x22eaf0b680a88c16, 0x5a65d25ac40e20f3,
14 0x34e7ac346236953e, 0x9dea3e0a26c6ba89, 0x0000000000000000,
15 0x0000000000000000, 0x0000000000000000};
16 uint64_t bb[] = {0x0000000024c0ffff, 0x000000004634d940, 0x00000000219d18ef,
17 0x0000000000154519, 0x000000000000035f, 0x0000000000000000,
18 0x0000000000000000, 0x0000000000000000};
19 char l[20];
20 l[0] = 0;
21 for (int i = 0; i < n; i++) {
22 a[i] = aa[i] + l[0] - '0';
23 b[i] = bb[i] + l[0] - '0';
24 }
25
26 // CHECK: TypeSanitizer: type-aliasing-violation on address
27 // CHECK-NEXT: READ of size 2 at {{.+}} with type short accesses an existing object of type long
28 // CHECK-NEXT: in f {{.*/?}}violation-pr47137.c:31
29 for (int i = 0, j = 0; j < 4 * m; i += 4, j += 3) {
30 for (int k = 0; k < 3; k++) {
31 ((uint16_t *)a)[j + k] = ((uint16_t *)a)[i + k];
32 ((uint16_t *)b)[j + k] = ((uint16_t *)b)[i + k];
33 }
34 }
35
36 printf(format: "a: %016llx\n", a[0]);
37 free(ptr: a);
38 free(ptr: b);
39}
40
41int main() { f(m: 6); }
42

source code of compiler-rt/test/tysan/violation-pr47137.c