Update copyright years.

[thirdparty/gcc.git] / libstdc++-v3 / src / c++11 / random.cc

diff --git a/libstdc++-v3/src/c++11/random.cc b/libstdc++-v3/src/c++11/random.cc
index 55a73c51fcaae8bf4dcda97c39ed4fcc41b7ead7..b4bf0a785fb98119f1dbb33fa7d1671602215e45 100644 (file)
--- a/libstdc++-v3/src/c++11/random.cc
+++ b/libstdc++-v3/src/c++11/random.cc
@@ -1,6 +1,6 @@
 // random -*- C++ -*-
 
-// Copyright (C) 2012-2021 Free Software Foundation, Inc.
+// Copyright (C) 2012-2024 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
@@ -26,8 +26,7 @@
 #define _CRT_RAND_S // define this before including <stdlib.h> to get rand_s
 
 #include <random>
-
-#ifdef  _GLIBCXX_USE_C99_STDINT_TR1
+#include <system_error>
 
 #if defined __i386__ || defined __x86_64__
 # include <cpuid.h>
@@ -37,7 +36,7 @@
 # ifdef _GLIBCXX_X86_RDSEED
 #  define USE_RDSEED 1
 # endif
-#elif defined __powerpc__ && defined __BUILTIN_CPU_SUPPORTS__
+#elif defined __powerpc64__ && defined __BUILTIN_CPU_SUPPORTS__
 # define USE_DARN 1
 #endif
 
@@ -68,7 +67,12 @@
 # include <stdlib.h>
 #endif
 
-#if defined _GLIBCXX_USE_CRT_RAND_S || defined _GLIBCXX_USE_DEV_RANDOM
+#ifdef _GLIBCXX_HAVE_GETENTROPY
+# include <unistd.h>
+#endif
+
+#if defined _GLIBCXX_USE_CRT_RAND_S || defined _GLIBCXX_USE_DEV_RANDOM \
+  || _GLIBCXX_HAVE_GETENTROPY
 // The OS provides a source of randomness we can use.
 # pragma GCC poison _M_mt
 #elif defined USE_RDRAND || defined USE_RDSEED || defined USE_DARN
@@ -89,6 +93,11 @@ namespace std _GLIBCXX_VISIBILITY(default)
 {
   namespace
   {
+    [[noreturn]]
+    inline void
+    __throw_syserr([[maybe_unused]] int e, [[maybe_unused]] const char* msg)
+    { _GLIBCXX_THROW_OR_ABORT(system_error(e, std::generic_category(), msg)); }
+
 #if USE_RDRAND
     unsigned int
     __attribute__ ((target("rdrnd")))
@@ -97,7 +106,7 @@ namespace std _GLIBCXX_VISIBILITY(default)
       unsigned int retries = 100;
       unsigned int val;
 
-      while (__builtin_ia32_rdrand32_step(&val) == 0)
+      while (__builtin_ia32_rdrand32_step(&val) == 0) [[__unlikely__]]
        if (--retries == 0)
          std::__throw_runtime_error(__N("random_device: rdrand failed"));
 
@@ -113,7 +122,7 @@ namespace std _GLIBCXX_VISIBILITY(default)
       unsigned int retries = 100;
       unsigned int val;
 
-      while (__builtin_ia32_rdseed_si_step(&val) == 0)
+      while (__builtin_ia32_rdseed_si_step(&val) == 0) [[__unlikely__]]
        {
          if (--retries == 0)
            {
@@ -166,6 +175,25 @@ namespace std _GLIBCXX_VISIBILITY(default)
     }
 #endif
 
+#ifdef _GLIBCXX_HAVE_GETENTROPY
+    unsigned int
+    __libc_getentropy(void*)
+    {
+      unsigned int val;
+      if (::getentropy(&val, sizeof(val)) != 0)
+       std::__throw_runtime_error(__N("random_device: getentropy failed"));
+      return val;
+    }
+#endif
+
+#ifdef _GLIBCXX_HAVE_ARC4RANDOM
+    unsigned int
+    __libc_arc4random(void*)
+    {
+      return ::arc4random();
+    }
+#endif
+
 #ifdef USE_LCG
     // TODO: use this to seed std::mt19937 engine too.
     unsigned
@@ -214,7 +242,7 @@ namespace std _GLIBCXX_VISIBILITY(default)
 #endif
 
     enum Which : unsigned {
-      device_file = 1, prng = 2, rand_s = 4,
+      device_file = 1, prng = 2, rand_s = 4, getentropy = 8, arc4random = 16,
       rdseed = 64, rdrand = 128, darn = 256,
       any = 0xffff
     };
@@ -256,6 +284,16 @@ namespace std _GLIBCXX_VISIBILITY(default)
        return device_file;
 #endif
 
+#ifdef _GLIBCXX_HAVE_ARC4RANDOM
+      if (func == __libc_arc4random)
+       return arc4random;
+#endif
+
+#ifdef _GLIBCXX_HAVE_GETENTROPY
+      if (func == __libc_getentropy)
+       return getentropy;
+#endif
+
 #ifdef USE_LCG
       if (func == &__lcg)
        return prng;
@@ -311,6 +349,14 @@ namespace std _GLIBCXX_VISIBILITY(default)
     else if (token == "rand_s")
       which = rand_s;
 #endif // _GLIBCXX_USE_CRT_RAND_S
+#ifdef _GLIBCXX_HAVE_GETENTROPY
+    else if (token == "getentropy")
+      which = getentropy;
+#endif // _GLIBCXX_HAVE_GETENTROPY
+#ifdef _GLIBCXX_HAVE_ARC4RANDOM
+    else if (token == "arc4random")
+      which = arc4random;
+#endif // _GLIBCXX_HAVE_ARC4RANDOM
 #ifdef _GLIBCXX_USE_DEV_RANDOM
     else if (token == "/dev/urandom" || token == "/dev/random")
       {
@@ -323,9 +369,18 @@ namespace std _GLIBCXX_VISIBILITY(default)
       which = prng;
 #endif
     else
-      std::__throw_runtime_error(
-         __N("random_device::random_device(const std::string&):"
-             " unsupported token"));
+      std::__throw_syserr(EINVAL, __N("random_device::random_device"
+                                     "(const std::string&):"
+                                     " unsupported token"));
+
+#if defined ENOSYS
+    [[maybe_unused]] const int unsupported = ENOSYS;
+#elif defined ENOTSUP
+    [[maybe_unused]] const int unsupported = ENOTSUP;
+#else
+    [[maybe_unused]] const int unsupported = 0;
+#endif
+    int err = 0;
 
 #ifdef _GLIBCXX_USE_CRT_RAND_S
     if (which & rand_s)
@@ -361,6 +416,7 @@ namespace std _GLIBCXX_VISIBILITY(default)
              return;
            }
        }
+      err = unsupported;
     }
 #endif // USE_RDSEED
 
@@ -381,6 +437,7 @@ namespace std _GLIBCXX_VISIBILITY(default)
              return;
            }
        }
+      err = unsupported;
     }
 #endif // USE_RDRAND
 
@@ -392,9 +449,31 @@ namespace std _GLIBCXX_VISIBILITY(default)
            _M_func = &__ppc_darn;
            return;
          }
+       err = unsupported;
       }
 #endif // USE_DARN
 
+#ifdef _GLIBCXX_HAVE_ARC4RANDOM
+    if (which & arc4random)
+      {
+       _M_func = &__libc_arc4random;
+       return;
+      }
+#endif // _GLIBCXX_HAVE_ARC4RANDOM
+
+#ifdef _GLIBCXX_HAVE_GETENTROPY
+    if (which & getentropy)
+      {
+       unsigned int i;
+       if (::getentropy(&i, sizeof(i)) == 0) // On linux the syscall can fail.
+         {
+           _M_func = &__libc_getentropy;
+           return;
+         }
+       err = unsupported;
+      }
+#endif // _GLIBCXX_HAVE_GETENTROPY
+
 #ifdef _GLIBCXX_USE_DEV_RANDOM
     if (which & device_file)
     {
@@ -411,6 +490,7 @@ namespace std _GLIBCXX_VISIBILITY(default)
       if (_M_file)
        return;
 #endif // USE_POSIX_FILE_IO
+      err = errno;
     }
 #endif // _GLIBCXX_USE_DEV_RANDOM
 
@@ -427,9 +507,12 @@ namespace std _GLIBCXX_VISIBILITY(default)
     }
 #endif
 
-    std::__throw_runtime_error(
-       __N("random_device::random_device(const std::string&):"
-           " device not available"));
+    auto msg = __N("random_device::random_device(const std::string&):"
+                  " device not available");
+    if (err)
+      std::__throw_syserr(err, msg);
+    else
+      std::__throw_runtime_error(msg);
 #endif // USE_MT19937
   }
 
@@ -446,8 +529,8 @@ namespace std _GLIBCXX_VISIBILITY(default)
        char* endptr;
        seed = std::strtoul(nptr, &endptr, 0);
        if (*nptr == '\0' || *endptr != '\0')
-         std::__throw_runtime_error(__N("random_device::_M_init_pretr1"
-                                        "(const std::string&)"));
+         std::__throw_syserr(EINVAL, __N("random_device::_M_init_pretr1"
+                                         "(const std::string&)"));
       }
     _M_mt.seed(seed);
 #else
@@ -486,6 +569,7 @@ namespace std _GLIBCXX_VISIBILITY(default)
       }
 #endif
 
+#ifdef _GLIBCXX_USE_DEV_RANDOM
 #ifdef USE_POSIX_FILE_IO
     ::close(_M_fd);
     _M_fd = -1;
@@ -493,6 +577,7 @@ namespace std _GLIBCXX_VISIBILITY(default)
     std::fclose(static_cast<FILE*>(_M_file));
 #endif
     _M_file = nullptr;
+#endif
   }
 
   random_device::result_type
@@ -518,7 +603,7 @@ namespace std _GLIBCXX_VISIBILITY(default)
            p = static_cast<char*>(p) + e;
          }
        else if (e != -1 || errno != EINTR)
-         __throw_runtime_error(__N("random_device could not be read"));
+         __throw_syserr(errno, __N("random_device could not be read"));
       }
     while (n > 0);
 #else // USE_POSIX_FILE_IO
@@ -548,6 +633,9 @@ namespace std _GLIBCXX_VISIBILITY(default)
     case rdseed:
     case darn:
       return (double) max;
+    case arc4random:
+    case getentropy:
+      return (double) max;
     case rand_s:
     case prng:
       return 0.0;
@@ -601,4 +689,3 @@ namespace std _GLIBCXX_VISIBILITY(default)
   template struct __detail::_Mod<unsigned, 2147483647UL, 16807UL, 0UL>;
 #endif
 }
-#endif // _GLIBCXX_USE_C99_STDINT_TR1