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
_M_init(const std::string & token)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
_M_init_pretr1(const std::string & token)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