libstdc++-v3/testsuite/20_util/unique_ptr/creation/for_overwrite.cc

   1 // { dg-options "-fno-lifetime-dse -O0" }
   2 // { dg-do run { target c++20 } }
   3 // { dg-xfail-run-if "AIX operator new" { powerpc-ibm-aix* } }
   4 // { dg-require-effective-target hosted }
   5 // { dg-add-options no_pch }
   6
   7 // Copyright (C) 2020-2024 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 // C++20 20.11.1.5 unique_ptr creation [unique.ptr.create]
  25
  26 #include <memory>
  27
  28 #ifndef __cpp_lib_smart_ptr_for_overwrite
  29 # error "Feature-test macro for make_unique_for_overwrite missing in <memory>"
  30 #elif __cpp_lib_smart_ptr_for_overwrite < 202002L
  31 # error "Feature-test macro for make_unique_for_overwrite has wrong value in <memory>"
  32 #endif
  33
  34 #include <cstdlib>
  35 #include <cstring>
  36 #include <testsuite_hooks.h>
  37
  38 void* operator new(std::size_t n)
  39 {
  40   void* p = std::malloc(n);
  41   std::memset(p, 0xaa, n);
  42   return p;
  43 }
  44
  45 void operator delete(void* p) noexcept { std::free(p); }
  46 void operator delete(void* p, std::size_t) noexcept { std::free(p); }
  47
  48 void
  49 test01()
  50 {
  51   std::unique_ptr<int> a = std::make_unique_for_overwrite<int>();
  52   VERIFY( a != nullptr );
  53   unsigned char buf[sizeof(int)];
  54   std::memcpy(buf, a.get(), sizeof(buf));
  55   for (unsigned char c : buf)
  56     VERIFY( c == 0xaa );
  57 }
  58
  59 void
  60 test02()
  61 {
  62   std::unique_ptr<int[]> a = std::make_unique_for_overwrite<int[]>(3);
  63   VERIFY( a != nullptr );
  64   unsigned char buf[3 * sizeof(int)];
  65   std::memcpy(buf, a.get(), sizeof(buf));
  66   for (unsigned char c : buf)
  67     VERIFY( c == 0xaa );
  68 }
  69
  70 void
  71 test03()
  72 {
  73   // Type with non-trivial initialization should still be default-initialized.
  74   struct NonTriv
  75   {
  76     int init = 0xbb;
  77     int uninit;
  78   };
  79   std::unique_ptr<NonTriv> a = std::make_unique_for_overwrite<NonTriv>();
  80   VERIFY( a->init == 0xbb );
  81   std::unique_ptr<NonTriv[]> b = std::make_unique_for_overwrite<NonTriv[]>(2);
  82   VERIFY( b[1].init == 0xbb );
  83 }
  84
  85 int
  86 main()
  87 {
  88   test01();
  89   test02();
  90   test03();
  91 }