src/compat/glibc_sanity.cpp

   1 // Copyright (c) 2009-2014 The Bitcoin Core developers
   2 // Distributed under the MIT software license, see the accompanying
   3 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
   4
   5 #if defined(HAVE_CONFIG_H)
   6 #include <config/bitcoin-config.h>
   7 #endif
   8
   9 #include <cstddef>
  10
  11 #if defined(HAVE_SYS_SELECT_H)
  12 #include <sys/select.h>
  13 #endif
  14
  15 extern "C" void* memcpy(void* a, const void* b, size_t c);
  16 void* memcpy_int(void* a, const void* b, size_t c)
  17 {
  18     return memcpy(a, b, c);
  19 }
  20
  21 namespace
  22 {
  23 // trigger: Use the memcpy_int wrapper which calls our internal memcpy.
  24 //   A direct call to memcpy may be optimized away by the compiler.
  25 // test: Fill an array with a sequence of integers. memcpy to a new empty array.
  26 //   Verify that the arrays are equal. Use an odd size to decrease the odds of
  27 //   the call being optimized away.
  28 template <unsigned int T>
  29 bool sanity_test_memcpy()
  30 {
  31     unsigned int memcpy_test[T];
  32     unsigned int memcpy_verify[T] = {};
  33     for (unsigned int i = 0; i != T; ++i)
  34         memcpy_test[i] = i;
  35
  36     memcpy_int(memcpy_verify, memcpy_test, sizeof(memcpy_test));
  37
  38     for (unsigned int i = 0; i != T; ++i) {
  39         if (memcpy_verify[i] != i)
  40             return false;
  41     }
  42     return true;
  43 }
  44
  45 #if defined(HAVE_SYS_SELECT_H)
  46 // trigger: Call FD_SET to trigger __fdelt_chk. FORTIFY_SOURCE must be defined
  47 //   as >0 and optimizations must be set to at least -O2.
  48 // test: Add a file descriptor to an empty fd_set. Verify that it has been
  49 //   correctly added.
  50 bool sanity_test_fdelt()
  51 {
  52     fd_set fds;
  53     FD_ZERO(&fds);
  54     FD_SET(0, &fds);
  55     return FD_ISSET(0, &fds);
  56 }
  57 #endif
  58
  59 } // namespace
  60
  61 bool glibc_sanity_test()
  62 {
  63 #if defined(HAVE_SYS_SELECT_H)
  64     if (!sanity_test_fdelt())
  65         return false;
  66 #endif
  67     return sanity_test_memcpy<1025>();
  68 }