compiler-rt/test/msan/fread_fwrite.cpp

   1 // RUN: %clangxx_msan -g %s -o %t
   2 // RUN: not %run %t 2>&1 | FileCheck %s
   3 // RUN: %t 1
   4
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7
   8 int test_fread() {
   9   FILE *f = fopen("/dev/zero", "r");
  10   char c;
  11   unsigned read = fread(&c, sizeof(c), 1, f);
  12   fclose(f);
  13   if (c == '1') // No error
  14     return 1;
  15   return 0;
  16 }
  17
  18 int test_fwrite() {
  19   FILE *f = fopen("/dev/null", "w");
  20   char c;
  21   if (fwrite(&c, sizeof(c), 1, f) != sizeof(c)) // BOOM
  22     return 1;
  23   return fclose(f);
  24 }
  25
  26 int main(int argc, char *argv[]) {
  27   if (argc > 1)
  28     test_fread();
  29   else
  30     test_fwrite();
  31   return 0;
  32 }
  33
  34 // CHECK: Uninitialized bytes in fwrite at offset 0 inside