xref: /llvm-project/compiler-rt/test/nsan/alloca.cpp (revision f4e8fbc5e90a4f2959a0eb6d7b01e7e279fb693b)
1 // RUN: %clangxx_nsan -O0 -g %s -o %t
2 // RUN: %run %t 2>&1 | FileCheck %s
3 
4 // RUN: %clangxx_nsan -O3 -g %s -o %t
5 // RUN: %run %t 2>&1 | FileCheck %s
6 
7 #include <cstddef>
8 
9 #include "helpers.h"
10 
11 extern "C" void __nsan_dump_shadow_mem(const char *addr, size_t size_bytes,
12                                        size_t bytes_per_line, size_t reserved);
13 
14 int main() {
15   int size = 3 * sizeof(float);
16   // Make sure we allocate dynamically: https://godbolt.org/z/T3h998.
17   DoNotOptimize(size);
18   float *array = reinterpret_cast<float *>(__builtin_alloca(size));
19   DoNotOptimize(array);
20   array[0] = 1.0;
21   array[1] = 2.0;
22   // The third float is uninitialized.
23   __nsan_dump_shadow_mem((const char *)array, 3 * sizeof(float), 16, 0);
24   // CHECK: {{.*}} f0 f1 f2 f3 f0 f1 f2 f3 __ __ __ __ (1.00000000000000000000) (2.00000000000000000000)
25   return 0;
26 }
27