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

   1 // { dg-do run { target c++11 } }
   2 // { dg-require-atomic-builtins "" }
   3
   4 // std::abs from <cstdlib> is not freestanding.
   5 // { dg-require-effective-target hosted }
   6
   7 // Copyright (C) 2012-2024 Free Software Foundation, Inc.
   8 //
   9 // This file is part of the GNU ISO C++ Library.  This library is free
  10 // software; you can redistribute it and/or modify it under the
  11 // terms of the GNU General Public License as published by the
  12 // Free Software Foundation; either version 3, or (at your option)
  13 // any later version.
  14
  15 // This library is distributed in the hope that it will be useful,
  16 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 // GNU General Public License for more details.
  19
  20 // You should have received a copy of the GNU General Public License along
  21 // with this library; see the file COPYING3.  If not see
  22 // <http://www.gnu.org/licenses/>.
  23
  24 #include <atomic>
  25 #include <cstdlib> //std::abs
  26 #include <testsuite_hooks.h>
  27
  28 // libstdc++/51811
  29 // pointer arithimetic vs. atomic<_Tp*> specialization
  30 int main(void)
  31 {
  32   using namespace std;
  33
  34   typedef int   value_type;
  35   const size_t n = 2;
  36   value_type value = 42;
  37   atomic<value_type*> p, p2, p3;
  38
  39   // operator++
  40   {
  41     p = &value;
  42     p2 = p++;
  43     VERIFY (p != p2);
  44
  45     value_type* vp(p);
  46     value_type* vp2(p2);
  47     ptrdiff_t dist = reinterpret_cast<char*>(vp) - reinterpret_cast<char*>(vp2);
  48     VERIFY ( std::abs(dist) == sizeof(value_type));
  49
  50     p = &value;
  51     p3 = ++p;
  52     VERIFY (p == p3);
  53   }
  54
  55   // operator--
  56   {
  57     p = &value;
  58     p2 = p--;
  59     VERIFY (p != p2);
  60
  61     value_type* vp(p);
  62     value_type* vp2(p2);
  63     ptrdiff_t dist = reinterpret_cast<char*>(vp) - reinterpret_cast<char*>(vp2);
  64     VERIFY ( std::abs(dist) == sizeof(value_type));
  65
  66     p = &value;
  67     p3 = --p;
  68     VERIFY (p == p3);
  69   }
  70
  71   // operator+=
  72   {
  73     p = &value;
  74     value_type* vp(p);
  75     p+=n;
  76     value_type* vp2(p);
  77     ptrdiff_t dist = reinterpret_cast<char*>(vp) - reinterpret_cast<char*>(vp2);
  78     VERIFY ( std::abs(dist) == sizeof(value_type) * n);
  79   }
  80
  81   // operator-=
  82   {
  83     p = &value;
  84     value_type* vp(p);
  85     p-=n;
  86     value_type* vp2(p);
  87     ptrdiff_t dist = reinterpret_cast<char*>(vp) - reinterpret_cast<char*>(vp2);
  88     VERIFY ( std::abs(dist) == sizeof(value_type) * n);
  89   }
  90
  91   return 0;
  92 }