compiler-rt/test/nsan/alloca.cpp

   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 }