libstdc++-v3/src/c++11/cow-string-inst.cc

   1 // Reference-counted COW string instantiations -*- C++ -*-
   2
   3 // Copyright (C) 2014-2018 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 3, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // Under Section 7 of GPL version 3, you are granted additional
  17 // permissions described in the GCC Runtime Library Exception, version
  18 // 3.1, as published by the Free Software Foundation.
  19
  20 // You should have received a copy of the GNU General Public License and
  21 // a copy of the GCC Runtime Library Exception along with this program;
  22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23 // <http://www.gnu.org/licenses/>.
  24
  25 //
  26 // ISO C++ 14882: 21  Strings library
  27 //
  28
  29 #define _GLIBCXX_USE_CXX11_ABI 0
  30 #include "string-inst.cc"
  31
  32 #if ! _GLIBCXX_USE_DUAL_ABI
  33 # error This file should not be compiled for this configuration.
  34 #endif
  35
  36 #ifdef  _GLIBCXX_USE_C99_STDINT_TR1
  37 #include <random>
  38 #if defined __i386__ || defined __x86_64__
  39 # include <cpuid.h>
  40 #endif
  41 #include <cstdio>
  42
  43 namespace std _GLIBCXX_VISIBILITY(default)
  44 {
  45   void
  46   random_device::_M_init(const std::string& token)
  47   {
  48     const char *fname = token.c_str();
  49
  50     if (token == "default")
  51       {
  52 #if (defined __i386__ || defined __x86_64__) && defined _GLIBCXX_X86_RDRAND
  53         unsigned int eax, ebx, ecx, edx;
  54         // Check availability of cpuid and, for now at least, also the
  55         // CPU signature for Intel's
  56         if (__get_cpuid_max(0, &ebx) > 0 && ebx == signature_INTEL_ebx)
  57           {
  58             __cpuid(1, eax, ebx, ecx, edx);
  59             if (ecx & bit_RDRND)
  60               {
  61                 _M_file = nullptr;
  62                 return;
  63               }
  64           }
  65 #endif
  66
  67         fname = "/dev/urandom";
  68       }
  69     else if (token != "/dev/urandom" && token != "/dev/random")
  70     fail:
  71       std::__throw_runtime_error(__N("random_device::"
  72                                      "random_device(const std::string&)"));
  73
  74     _M_file = static_cast<void*>(std::fopen(fname, "rb"));
  75     if (!_M_file)
  76       goto fail;
  77   }
  78
  79   void
  80   random_device::_M_init_pretr1(const std::string& token)
  81   {
  82     unsigned long __seed = 5489UL;
  83     if (token != "mt19937")
  84       {
  85         const char* __nptr = token.c_str();
  86         char* __endptr;
  87         __seed = std::strtoul(__nptr, &__endptr, 0);
  88         if (*__nptr == '\0' || *__endptr != '\0')
  89           std::__throw_runtime_error(__N("random_device::random_device"
  90                                          "(const std::string&)"));
  91       }
  92     _M_mt.seed(__seed);
  93   }
  94 } // namespace
  95 #endif