libstdc++-v3/testsuite/29_atomics/atomic/operators/51811.cc

   1 // { dg-do run { target c++11 } }
   2 // { dg-require-atomic-builtins "" }
   3
   4 // Copyright (C) 2012-2020 Free Software Foundation, Inc.
   5 //
   6 // This file is part of the GNU ISO C++ Library.  This library is free
   7 // software; you can redistribute it and/or modify it under the
   8 // terms of the GNU General Public License as published by the
   9 // Free Software Foundation; either version 3, or (at your option)
  10 // any later version.
  11
  12 // This library is distributed in the hope that it will be useful,
  13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 // GNU General Public License for more details.
  16
  17 // You should have received a copy of the GNU General Public License along
  18 // with this library; see the file COPYING3.  If not see
  19 // <http://www.gnu.org/licenses/>.
  20
  21 #include <atomic>
  22 #include <cstdlib> //std::abs
  23 #include <testsuite_hooks.h>
  24
  25 // libstdc++/51811
  26 // pointer arithimetic vs. atomic<_Tp*> specialization
  27 int main(void)
  28 {
  29   using namespace std;
  30
  31   typedef int   value_type;
  32   const size_t n = 2;
  33   value_type value = 42;
  34   atomic<value_type*> p, p2, p3;
  35
  36   // operator++
  37   {
  38     p = &value;
  39     p2 = p++;
  40     VERIFY (p != p2);
  41
  42     value_type* vp(p);
  43     value_type* vp2(p2);
  44     ptrdiff_t dist = reinterpret_cast<char*>(vp) - reinterpret_cast<char*>(vp2);
  45     VERIFY ( std::abs(dist) == sizeof(value_type));
  46
  47     p = &value;
  48     p3 = ++p;
  49     VERIFY (p == p3);
  50   }
  51
  52   // operator--
  53   {
  54     p = &value;
  55     p2 = p--;
  56     VERIFY (p != p2);
  57
  58     value_type* vp(p);
  59     value_type* vp2(p2);
  60     ptrdiff_t dist = reinterpret_cast<char*>(vp) - reinterpret_cast<char*>(vp2);
  61     VERIFY ( std::abs(dist) == sizeof(value_type));
  62
  63     p = &value;
  64     p3 = --p;
  65     VERIFY (p == p3);
  66   }
  67
  68   // operator+=
  69   {
  70     p = &value;
  71     value_type* vp(p);
  72     p+=n;
  73     value_type* vp2(p);
  74     ptrdiff_t dist = reinterpret_cast<char*>(vp) - reinterpret_cast<char*>(vp2);
  75     VERIFY ( std::abs(dist) == sizeof(value_type) * n);
  76   }
  77
  78   // operator-=
  79   {
  80     p = &value;
  81     value_type* vp(p);
  82     p-=n;
  83     value_type* vp2(p);
  84     ptrdiff_t dist = reinterpret_cast<char*>(vp) - reinterpret_cast<char*>(vp2);
  85     VERIFY ( std::abs(dist) == sizeof(value_type) * n);
  86   }
  87
  88   return 0;
  89 }