1*673dc3d4SNico Weber // RUN: %clangxx_asan -O0 %s -o %t
2*673dc3d4SNico Weber // RUN: not %run %t 2>&1 | FileCheck %s
3*673dc3d4SNico Weber 
4*673dc3d4SNico Weber struct A {
5*673dc3d4SNico Weber   int a[8];
6*673dc3d4SNico Weber };
7*673dc3d4SNico Weber 
bar(A * a)8*673dc3d4SNico Weber int bar(A *a) {
9*673dc3d4SNico Weber   int *volatile ptr = &a->a[0];
10*673dc3d4SNico Weber   return *(ptr - 1);
11*673dc3d4SNico Weber }
12*673dc3d4SNico Weber 
foo(A a)13*673dc3d4SNico Weber void foo(A a) {
14*673dc3d4SNico Weber   bar(&a);
15*673dc3d4SNico Weber }
16*673dc3d4SNico Weber 
main()17*673dc3d4SNico Weber int main() {
18*673dc3d4SNico Weber   foo(A());
19*673dc3d4SNico Weber }
20*673dc3d4SNico Weber 
21*673dc3d4SNico Weber // CHECK: ERROR: AddressSanitizer: stack-buffer-underflow
22*673dc3d4SNico Weber // CHECK: READ of size 4 at
23*673dc3d4SNico Weber // CHECK: is located in stack of thread
24