libstdc++-v3/testsuite/27_io/basic_filebuf/underflow/wchar_t/9178.cc

   1 // Copyright (C) 2003-2022 Free Software Foundation, Inc.
   2 //
   3 // This file is part of the GNU ISO C++ Library.  This library is free
   4 // software; you can redistribute it and/or modify it under the
   5 // terms of the GNU General Public License as published by the
   6 // Free Software Foundation; either version 3, or (at your option)
   7 // any later version.
   8
   9 // This library is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13
  14 // You should have received a copy of the GNU General Public License along
  15 // with this library; see the file COPYING3.  If not see
  16 // <http://www.gnu.org/licenses/>.
  17
  18 // 27.8.1.4 Overridden virtual functions
  19
  20 #include <fstream>
  21 #include <string>
  22 #include <iterator>
  23 #include <algorithm>
  24 #include <locale>
  25 #include <testsuite_hooks.h>
  26
  27 template <typename InternT, typename StateT = mbstate_t>
  28 class checksumcvt : public std::codecvt<InternT, char, StateT>
  29 {
  30   typedef std::codecvt<InternT, char, StateT> Base;
  31   static const size_t width = sizeof(InternT) + 1;
  32
  33 public:
  34   typedef InternT intern_type;
  35   typedef char extern_type;
  36
  37   explicit checksumcvt(size_t refs = 0)
  38   : Base(refs)
  39   { }
  40
  41 protected:
  42   virtual typename std::codecvt<InternT, char, StateT>::result
  43   do_out(StateT&, const intern_type* from,
  44          const intern_type* from_end, const intern_type*& from_next,
  45          extern_type* to, extern_type* to_end,
  46          extern_type*& to_next) const
  47   {
  48     size_t len = std::min(static_cast<size_t>(from_end - from),
  49                           static_cast<size_t>(to_end - to) / width);
  50
  51     while (len--)
  52       {
  53         const char* p = reinterpret_cast<const char*>(from);
  54         unsigned char checksum = 0;
  55
  56         for (size_t i = 0; i < sizeof(intern_type); ++i)
  57           {
  58             *to++ = p[i];
  59             checksum ^= static_cast<unsigned char>(p[i]);
  60           }
  61
  62         *to++ = checksum;
  63         ++from;
  64       }
  65
  66     from_next = from;
  67     to_next = to;
  68     return from_next == from_end ? std::codecvt<InternT, char, StateT>::ok
  69            : std::codecvt<InternT, char, StateT>::partial;
  70   }
  71
  72   virtual typename std::codecvt<InternT, char, StateT>::result
  73   do_unshift(StateT&, extern_type* to,
  74              extern_type*, extern_type*& to_next) const
  75   {
  76     to_next = to;
  77     return std::codecvt<InternT, char, StateT>::ok;
  78   }
  79
  80   virtual typename std::codecvt<InternT, char, StateT>::result
  81   do_in(StateT&, const extern_type* from,
  82         const extern_type* from_end, const extern_type*& from_next,
  83         intern_type* to, intern_type* to_end,
  84         intern_type*& to_next) const
  85   {
  86     size_t len = std::min(static_cast<size_t>(to_end - to),
  87                           static_cast<size_t>(from_end - from) / width);
  88
  89     while (len)
  90       {
  91         const char* f = from;
  92         intern_type tmp;
  93         char* p = reinterpret_cast<char*>(&tmp);
  94         unsigned char checksum = 0;
  95
  96         for (size_t i = 0; i < sizeof(intern_type); ++i)
  97           {
  98             p[i] = *f;
  99             checksum ^= static_cast<unsigned char>(*f++);
 100           }
 101
 102         if (*f++ != checksum)
 103           break;
 104
 105         from = f;
 106         *to++ = tmp;
 107         len--;
 108       }
 109
 110     from_next = from;
 111     to_next = to;
 112     return len ? std::codecvt<InternT, char, StateT>::error :
 113       (from_next == from_end ? std::codecvt<InternT, char, StateT>::ok
 114        : std::codecvt<InternT, char, StateT>::partial);
 115   }
 116
 117   virtual int
 118   do_encoding() const throw()
 119   {
 120     return width;
 121   }
 122
 123   virtual int
 124   do_length(StateT&, const extern_type* from,
 125             const extern_type* end, size_t max) const
 126   {
 127     size_t len = std::min(max, static_cast<size_t>(end - from) / width);
 128
 129     int ret = 0;
 130     while (len--)
 131       {
 132         unsigned char checksum = 0;
 133
 134         for (size_t i = 0; i < sizeof(intern_type); ++i)
 135           {
 136             checksum ^= static_cast<unsigned char>(*from++);
 137           }
 138
 139         if (*from++ != checksum)
 140           break;
 141
 142         ret++;
 143       }
 144
 145     return ret;
 146   }
 147
 148   virtual int
 149   do_max_length() const throw()
 150   {
 151     return width;
 152   }
 153
 154   virtual bool
 155   do_always_noconv() const throw()
 156   {
 157     return false;
 158   }
 159 };
 160
 161 void test01()
 162 {
 163   using namespace std;
 164
 165   locale loc;
 166   loc = locale(loc, new checksumcvt<wchar_t>);
 167
 168   wfilebuf fbuf1;
 169   fbuf1.pubimbue(loc);
 170   fbuf1.open("tmp_9178", ios_base::out | ios_base::trunc);
 171
 172   string tmpstr = "abcdefghijklmnopqrstuvwxyz0123456789 \t\n";
 173
 174   wifstream stream;
 175   wstring str1;
 176
 177   while (str1.length() < 20000)
 178     {
 179       transform(tmpstr.begin(), tmpstr.end(),
 180                 back_inserter(str1),
 181                 bind1st(std::mem_fun(&std::wios::widen), &stream));
 182     }
 183
 184   fbuf1.sputn(str1.data(), str1.size());
 185   fbuf1.close();
 186
 187   wfilebuf fbuf2;
 188   fbuf2.pubimbue(loc);
 189   fbuf2.open("tmp_9178", std::ios_base::in);
 190
 191   wstring str2;
 192   copy(istreambuf_iterator<wchar_t>(&fbuf2),
 193        istreambuf_iterator<wchar_t>(),
 194        back_inserter(str2));
 195
 196   VERIFY( str1 == str2 );
 197 }
 198
 199 int main()
 200 {
 201   test01();
 202   return 0;
 203 }