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 // The behavior of std::random_device changed on Apple platforms with
  10 // https://llvm.org/D116045 (d202c76441e1).
  11 // XFAIL: target={{.+}}-apple-{{.+}} && using-built-library-before-llvm-14
  12
  13 // UNSUPPORTED: no-random-device
  14
  15 // <random>
  16
  17 // class random_device;
  18
  19 // explicit random_device(const string& token = implementation-defined); // before C++20
  20 // random_device() : random_device(implementation-defined) {}            // C++20
  21 // explicit random_device(const string& token);                          // C++20
  22
  23 // For the following ctors, the standard states: "The semantics and default
  24 // value of the token parameter are implementation-defined". Implementations
  25 // therefore aren't required to accept any string, but the default shouldn't
  26 // throw.
  27
  28 #include <random>
  29 #include <string>
  30 #include <system_error>
  31 #include <cassert>
  32
  33 #if !defined(_WIN32)
  34 #include <unistd.h>
  35 #endif
  36
  37 #include "test_macros.h"
  38 #if TEST_STD_VER >= 11
  39 #include "test_convertible.h"
  40 #endif
  41
  42 void check_random_device_valid(const std::string &token) {
  43   std::random_device r(token);
  44 }
  45
  46 void check_random_device_invalid(const std::string &token) {
  47 #ifndef TEST_HAS_NO_EXCEPTIONS
  48   try {
  49     std::random_device r(token);
  50     LIBCPP_ASSERT(false);
  51   } catch (const std::system_error&) {
  52   }
  53 #else
  54   ((void)token);
  55 #endif
  56 }
  57
  58 int main(int, char**) {
  59   {
  60     std::random_device r;
  61     (void)r;
  62   }
  63   // Check the validity of various tokens
  64   {
  65 #if defined(_LIBCPP_USING_ARC4_RANDOM)
  66     check_random_device_valid("/dev/urandom");
  67     check_random_device_valid("/dev/random");
  68     check_random_device_valid("/dev/null");
  69     check_random_device_valid("/dev/nonexistent");
  70     check_random_device_valid("wrong file");
  71 #elif defined(_LIBCPP_USING_DEV_RANDOM)
  72     check_random_device_valid("/dev/urandom");
  73     check_random_device_valid("/dev/random");
  74     check_random_device_valid("/dev/null");
  75     check_random_device_invalid("/dev/nonexistent");
  76     check_random_device_invalid("wrong file");
  77 #else
  78     check_random_device_valid("/dev/urandom");
  79     check_random_device_invalid("/dev/random");
  80     check_random_device_invalid("/dev/null");
  81     check_random_device_invalid("/dev/nonexistent");
  82     check_random_device_invalid("wrong file");
  83 #endif
  84   }
  85
  86 #if !defined(_WIN32)
  87 // Test that random_device(const string&) properly handles getting
  88 // a file descriptor with the value '0'. Do this by closing the standard
  89 // streams so that the descriptor '0' is available.
  90   {
  91     int ec;
  92     ec = close(STDIN_FILENO);
  93     assert(!ec);
  94     ec = close(STDOUT_FILENO);
  95     assert(!ec);
  96     ec = close(STDERR_FILENO);
  97     assert(!ec);
  98     std::random_device r;
  99   }
 100 #endif // !defined(_WIN32)
 101
 102 #if TEST_STD_VER >= 11
 103   static_assert(test_convertible<std::random_device>(), "");
 104 #endif
 105
 106   return 0;
 107 }