libcxx/test/std/numerics/rand/rand.device/ctor.pass.cpp

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 // See https://llvm.org/PR20183
  10 // XFAIL: stdlib=apple-libc++ && target={{.+}}-apple-macosx10.{{9|10|11}}
  11
  12 // The behavior of std::random_device changed on Apple platforms with
  13 // https://llvm.org/D116045.
  14 // XFAIL: stdlib=apple-libc++ && target={{.+}}-apple-macosx{{10.9|10.10|10.11|10.12|10.13|10.14|10.15|11.0|12.0}}
  15
  16 // UNSUPPORTED: no-random-device
  17
  18 // <random>
  19
  20 // class random_device;
  21
  22 // explicit random_device(const string& token = implementation-defined); // before C++20
  23 // random_device() : random_device(implementation-defined) {}            // C++20
  24 // explicit random_device(const string& token);                          // C++20
  25
  26 // For the following ctors, the standard states: "The semantics and default
  27 // value of the token parameter are implementation-defined". Implementations
  28 // therefore aren't required to accept any string, but the default shouldn't
  29 // throw.
  30
  31 #include <random>
  32 #include <string>
  33 #include <system_error>
  34 #include <cassert>
  35
  36 #if !defined(_WIN32)
  37 #include <unistd.h>
  38 #endif
  39
  40 #include "test_macros.h"
  41 #if TEST_STD_VER >= 11
  42 #include "test_convertible.h"
  43 #endif
  44
  45 void check_random_device_valid(const std::string &token) {
  46   std::random_device r(token);
  47 }
  48
  49 void check_random_device_invalid(const std::string &token) {
  50 #ifndef TEST_HAS_NO_EXCEPTIONS
  51   try {
  52     std::random_device r(token);
  53     LIBCPP_ASSERT(false);
  54   } catch (const std::system_error&) {
  55   }
  56 #else
  57   ((void)token);
  58 #endif
  59 }
  60
  61 int main(int, char**) {
  62   {
  63     std::random_device r;
  64   }
  65   // Check the validity of various tokens
  66   {
  67 #if defined(_LIBCPP_USING_ARC4_RANDOM)
  68     check_random_device_valid("/dev/urandom");
  69     check_random_device_valid("/dev/random");
  70     check_random_device_valid("/dev/null");
  71     check_random_device_valid("/dev/nonexistent");
  72     check_random_device_valid("wrong file");
  73 #elif defined(_LIBCPP_USING_DEV_RANDOM)
  74     check_random_device_valid("/dev/urandom");
  75     check_random_device_valid("/dev/random");
  76     check_random_device_valid("/dev/null");
  77     check_random_device_invalid("/dev/nonexistent");
  78     check_random_device_invalid("wrong file");
  79 #else
  80     check_random_device_valid("/dev/urandom");
  81     check_random_device_invalid("/dev/random");
  82     check_random_device_invalid("/dev/null");
  83     check_random_device_invalid("/dev/nonexistent");
  84     check_random_device_invalid("wrong file");
  85 #endif
  86   }
  87
  88 #if !defined(_WIN32)
  89 // Test that random_device(const string&) properly handles getting
  90 // a file descriptor with the value '0'. Do this by closing the standard
  91 // streams so that the descriptor '0' is available.
  92   {
  93     int ec;
  94     ec = close(STDIN_FILENO);
  95     assert(!ec);
  96     ec = close(STDOUT_FILENO);
  97     assert(!ec);
  98     ec = close(STDERR_FILENO);
  99     assert(!ec);
 100     std::random_device r;
 101   }
 102 #endif // !defined(_WIN32)
 103
 104 #if TEST_STD_VER >= 11
 105   static_assert(test_convertible<std::random_device>(), "");
 106 #endif
 107
 108   return 0;
 109 }