Louis Dionne db8c7e004a
[libc++] Fix deployment target Lit features ()
We were not making any distinction between e.g. the "Apple-flavored"
libc++ built from trunk and the system-provided standard library on
Apple platforms. For example, any test that would be XFAILed on a
back-deployment target would unexpectedly pass when run on that
deployment target against the tip of trunk Apple-flavored libc++. In
reality, that test would be expected to pass because we're running
against the latest libc++, even if it is Apple-flavored.

To solve this issue, we introduce a new feature that describes whether
the Standard Library in use is the one provided by the system by
default, and that notion is different from the underlying standard
library flavor. We also refactor the existing Lit features to make a
distinction between availability markup and the library we're running
against at runtime, which otherwise limit the flexibility of what we can
express in the test suite. Finally, we refactor some of the
back-deployment versions that were incorrect (such as thinking that LLVM
10 was introduced in macOS 11, when in reality macOS 11 was synced with
LLVM 11).

Fixes 
2024-06-21 10:31:22 -04:00

111 lines
3.2 KiB
C++

//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// See https://llvm.org/PR20183
// XFAIL: stdlib=system && target={{.+}}-apple-macosx10.{{9|10|11}}
// The behavior of std::random_device changed on Apple platforms with
// https://llvm.org/D116045.
// XFAIL: stdlib=system && target={{.+}}-apple-macosx{{10.9|10.10|10.11|10.12|10.13|10.14|10.15|11.0|12.0}}
// UNSUPPORTED: no-random-device
// <random>
// class random_device;
// explicit random_device(const string& token = implementation-defined); // before C++20
// random_device() : random_device(implementation-defined) {} // C++20
// explicit random_device(const string& token); // C++20
// For the following ctors, the standard states: "The semantics and default
// value of the token parameter are implementation-defined". Implementations
// therefore aren't required to accept any string, but the default shouldn't
// throw.
#include <random>
#include <string>
#include <system_error>
#include <cassert>
#if !defined(_WIN32)
#include <unistd.h>
#endif
#include "test_macros.h"
#if TEST_STD_VER >= 11
#include "test_convertible.h"
#endif
void check_random_device_valid(const std::string &token) {
std::random_device r(token);
}
void check_random_device_invalid(const std::string &token) {
#ifndef TEST_HAS_NO_EXCEPTIONS
try {
std::random_device r(token);
LIBCPP_ASSERT(false);
} catch (const std::system_error&) {
}
#else
((void)token);
#endif
}
int main(int, char**) {
{
std::random_device r;
(void)r;
}
// Check the validity of various tokens
{
#if defined(_LIBCPP_USING_ARC4_RANDOM)
check_random_device_valid("/dev/urandom");
check_random_device_valid("/dev/random");
check_random_device_valid("/dev/null");
check_random_device_valid("/dev/nonexistent");
check_random_device_valid("wrong file");
#elif defined(_LIBCPP_USING_DEV_RANDOM)
check_random_device_valid("/dev/urandom");
check_random_device_valid("/dev/random");
check_random_device_valid("/dev/null");
check_random_device_invalid("/dev/nonexistent");
check_random_device_invalid("wrong file");
#else
check_random_device_valid("/dev/urandom");
check_random_device_invalid("/dev/random");
check_random_device_invalid("/dev/null");
check_random_device_invalid("/dev/nonexistent");
check_random_device_invalid("wrong file");
#endif
}
#if !defined(_WIN32)
// Test that random_device(const string&) properly handles getting
// a file descriptor with the value '0'. Do this by closing the standard
// streams so that the descriptor '0' is available.
{
int ec;
ec = close(STDIN_FILENO);
assert(!ec);
ec = close(STDOUT_FILENO);
assert(!ec);
ec = close(STDERR_FILENO);
assert(!ec);
std::random_device r;
}
#endif // !defined(_WIN32)
#if TEST_STD_VER >= 11
static_assert(test_convertible<std::random_device>(), "");
#endif
return 0;
}