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 96