PR libstdc++/85494 use rand_s in std::random_device

This is a minimal fix for the use of a deterministic RNG on mingw-w64,
simply using rand_s unconditionally. The rest of the r271740 changes on
trunk are not included. That means that RDSEED and RDRAND are not
available for mingw-w64 and the token passed to the constructor is
ignored completely.

	PR libstdc++/85494 use rand_s in std::random_device
	* config/os/mingw32-w64/os_defines.h (_GLIBCXX_USE_CRT_RAND_S): Define.
	* src/c++11/cow-string-inst.cc (random_device::_M_init_pretr1)
	[_GLIBCXX_USE_CRT_RAND_S]: Do nothing if rand_s will be used.
	* src/c++11/random.cc [_GLIBCXX_USE_CRT_RAND_S] (__winxp_rand_s):
	Define new function.
	(random_device::_M_init_pretr1) [_GLIBCXX_USE_CRT_RAND_S]: Do nothing
	if rand_s will be used.
	(random_device::_M_getval_pretr1) [_GLIBCXX_USE_CRT_RAND_S]: Use
	__winxp_rand_s().
	* testsuite/26_numerics/random/random_device/85494.cc: New test.

From-SVN: r272748

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index e641f0eadf7408d4a4ae35f656ec85ed8902bcff..1ca540f3ede55ccc5c920feb6d5ab8a8f95a52d8 100644 (file)
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,5 +1,17 @@
 2019-06-27  Jonathan Wakely  <jwakely@redhat.com>
 
+       PR libstdc++/85494 use rand_s in std::random_device
+       * config/os/mingw32-w64/os_defines.h (_GLIBCXX_USE_CRT_RAND_S): Define.
+       * src/c++11/cow-string-inst.cc (random_device::_M_init_pretr1)
+       [_GLIBCXX_USE_CRT_RAND_S]: Do nothing if rand_s will be used.
+       * src/c++11/random.cc [_GLIBCXX_USE_CRT_RAND_S] (__winxp_rand_s):
+       Define new function.
+       (random_device::_M_init_pretr1) [_GLIBCXX_USE_CRT_RAND_S]: Do nothing
+       if rand_s will be used.
+       (random_device::_M_getval_pretr1) [_GLIBCXX_USE_CRT_RAND_S]: Use
+       __winxp_rand_s().
+       * testsuite/26_numerics/random/random_device/85494.cc: New test.
+
        PR libstdc++/91012
        * src/c++17/fs_path.cc (filesystem_error::_Impl): Use a string_view
        for the what_arg parameters.

diff --git a/libstdc++-v3/config/os/mingw32-w64/os_defines.h b/libstdc++-v3/config/os/mingw32-w64/os_defines.h
index 6c19d3953a61f2e4a82c43b3e2bbd6490e32ef84..418c6f569df257b6c8a296a82e3d1e930dc48b27 100644 (file)
--- a/libstdc++-v3/config/os/mingw32-w64/os_defines.h
+++ b/libstdc++-v3/config/os/mingw32-w64/os_defines.h
@@ -88,4 +88,6 @@
 // See libstdc++/59807
 #define _GTHREAD_USE_MUTEX_INIT_FUNC 1
 
+#define _GLIBCXX_USE_CRT_RAND_S 1
+
 #endif

diff --git a/libstdc++-v3/src/c++11/cow-string-inst.cc b/libstdc++-v3/src/c++11/cow-string-inst.cc
index c36f297438eca6868ed2154c9d6eba72d999bc36..a5e4ad29dc30af00b09a77a7360da1cf2cced300 100644 (file)
--- a/libstdc++-v3/src/c++11/cow-string-inst.cc
+++ b/libstdc++-v3/src/c++11/cow-string-inst.cc
@@ -77,8 +77,9 @@ namespace std _GLIBCXX_VISIBILITY(default)
   }
 
   void
-  random_device::_M_init_pretr1(const std::string& token)
+  random_device::_M_init_pretr1(const std::string& token [[gnu::unused]])
   {
+#ifndef _GLIBCXX_USE_CRT_RAND_S
     unsigned long __seed = 5489UL;
     if (token != "mt19937")
       {
@@ -90,6 +91,7 @@ namespace std _GLIBCXX_VISIBILITY(default)
                                         "(const std::string&)"));
       }
     _M_mt.seed(__seed);
+#endif
   }
 } // namespace
 #endif

diff --git a/libstdc++-v3/src/c++11/random.cc b/libstdc++-v3/src/c++11/random.cc
index 1146d21c3f9b00db920622ab4436c343cf9ccb62..0bb6b6bf5b8c1ffe0be8b78fca58066ac85a675e 100644 (file)
--- a/libstdc++-v3/src/c++11/random.cc
+++ b/libstdc++-v3/src/c++11/random.cc
@@ -23,6 +23,8 @@
 // <http://www.gnu.org/licenses/>.
 
 #define _GLIBCXX_USE_CXX11_ABI 1
+#define _CRT_RAND_S // define this before including <stdlib.h> to get rand_s
+
 #include <random>
 
 #ifdef  _GLIBCXX_USE_C99_STDINT_TR1
@@ -50,6 +52,10 @@
 # include <linux/random.h>
 #endif
 
+#ifdef _GLIBCXX_USE_CRT_RAND_S
+# include <stdlib.h>
+#endif
+
 namespace std _GLIBCXX_VISIBILITY(default)
 {
   namespace
@@ -85,6 +91,18 @@ namespace std _GLIBCXX_VISIBILITY(default)
       return val;
     }
 #endif
+
+#ifdef _GLIBCXX_USE_CRT_RAND_S
+# pragma GCC poison _M_mt
+    unsigned int
+    __winxp_rand_s()
+    {
+      unsigned int val;
+      if (::rand_s(&val) != 0)
+       std::__throw_runtime_error(__N("random_device: rand_s failed"));
+      return val;
+    }
+#endif
   }
 
   void
@@ -122,9 +140,11 @@ namespace std _GLIBCXX_VISIBILITY(default)
   }
 
   void
-  random_device::_M_init_pretr1(const std::string& token)
+  random_device::_M_init_pretr1(const std::string& token [[gnu::unused]])
   {
+#ifndef _GLIBCXX_USE_CRT_RAND_S
     _M_mt.seed(_M_strtoul(token));
+#endif
   }
 
   void
@@ -170,7 +190,11 @@ namespace std _GLIBCXX_VISIBILITY(default)
   random_device::result_type
   random_device::_M_getval_pretr1()
   {
+#ifdef _GLIBCXX_USE_CRT_RAND_S
+    return __winxp_rand_s();
+#else
     return _M_mt();
+#endif
   }
 
   double

diff --git a/libstdc++-v3/testsuite/26_numerics/random/random_device/85494.cc b/libstdc++-v3/testsuite/26_numerics/random/random_device/85494.cc
new file mode 100644 (file)
index 0000000..2670ad7
--- /dev/null
+++ b/libstdc++-v3/testsuite/26_numerics/random/random_device/85494.cc
@@ -0,0 +1,40 @@
+// Copyright (C) 2019 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-do run { target c++11 } }
+// { dg-require-effective-target random_device }
+
+#include <random>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  unsigned v1[3], v2[3];
+  std::random_device d1, d2;
+  for (auto& v : v1)
+    v = d1();
+  for (auto& v : v2)
+    v = d2();
+  VERIFY (v1[0] != v2[0] || v1[1] != v2[1] || v1[2] != v2[2] );
+}
+
+int
+main()
+{
+  test01();
+}