Files
swift-mirror/stdlib/public/stubs/Random.cpp
Egor Zhdan 84a1ffcb33 [Shims] Include SwiftShims headers without ../
This replaces a number of `#include`-s like this:
```
#include "../../../stdlib/public/SwiftShims/Visibility.h"
```
with this:
```
#include "swift/shims/Visibility.h"
```

This is needed to allow SwiftCompilerSources to use C++ headers which include SwiftShims headers. Currently trying to do that results in errors:
```
swift/swift/include/swift/Demangling/../../../stdlib/public/SwiftShims/module.modulemap:1:8: error: redefinition of module 'SwiftShims'
module SwiftShims {
       ^
Builds.noindex/swift/swift/bootstrapping0/lib/swift/shims/module.modulemap:1:8: note: previously defined here
module SwiftShims {
       ^
```
This happens because the headers in both the source dir and the build dir refer to SwiftShims headers by relative path, and both the source root and the build root contain SwiftShims headers (which are equivalent, but since they are located in different dirs, Clang treats them as different modules).
2022-09-14 11:14:50 +01:00

134 lines
3.8 KiB
C++

//===--- Random.cpp -------------------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2018 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
// swift_stdlib_random
//
// Should the implementation of this function add a new platform/change for a
// platform, make sure to also update the documentation regarding platform
// implementation of this function.
// This can be found at: /docs/Random.md
#if defined(_WIN32) && !defined(__CYGWIN__)
#define WIN32_LEAN_AND_MEAN
#include <Windows.h>
#include <Bcrypt.h>
#pragma comment(lib, "bcrypt.lib")
#elif !defined(__APPLE__)
#include <errno.h>
#include <fcntl.h>
#if __has_include(<sys/random.h>)
#include <sys/random.h>
#endif
#if __has_include(<sys/stat.h>)
#include <sys/stat.h>
#endif
#if __has_include(<sys/syscall.h>)
#include <sys/syscall.h>
#endif
#endif
#if __has_include(<unistd.h>)
#include <unistd.h>
#endif
#include <stdlib.h>
#include "swift/shims/Random.h"
#include "swift/Runtime/Debug.h"
#include "swift/Threading/Mutex.h"
#include <algorithm> // required for std::min
using namespace swift;
#if defined(__APPLE__)
SWIFT_RUNTIME_STDLIB_API
void swift_stdlib_random(void *buf, __swift_size_t nbytes) {
arc4random_buf(buf, nbytes);
}
#elif defined(_WIN32) && !defined(__CYGWIN__)
#warning TODO: Test swift_stdlib_random on Windows
SWIFT_RUNTIME_STDLIB_API
void swift_stdlib_random(void *buf, __swift_size_t nbytes) {
if (nbytes > ULONG_MAX) {
fatalError(0, "Fatal error: %zd exceeds ULONG_MAX\n", nbytes);
}
NTSTATUS status = BCryptGenRandom(nullptr,
static_cast<PUCHAR>(buf),
static_cast<ULONG>(nbytes),
BCRYPT_USE_SYSTEM_PREFERRED_RNG);
if (!BCRYPT_SUCCESS(status)) {
fatalError(0, "Fatal error: 0x%lX in '%s'\n", status, __func__);
}
}
#else
#undef WHILE_EINTR
#define WHILE_EINTR(expression) ([&] () -> decltype(expression) { \
decltype(expression) result = -1; \
do { result = (expression); } while (result == -1 && errno == EINTR); \
return result; \
}())
SWIFT_RUNTIME_STDLIB_API
void swift_stdlib_random(void *buf, __swift_size_t nbytes) {
while (nbytes > 0) {
__swift_ssize_t actual_nbytes = -1;
#if defined(__NR_getrandom)
static const bool getrandom_available =
!(syscall(__NR_getrandom, nullptr, 0, 0) == -1 && errno == ENOSYS);
if (getrandom_available) {
actual_nbytes = WHILE_EINTR(syscall(__NR_getrandom, buf, nbytes, 0));
}
#elif __has_include(<sys/random.h>) && (defined(__CYGWIN__) || defined(__Fuchsia__) || defined(__wasi__))
__swift_size_t getentropy_nbytes = std::min(nbytes, __swift_size_t{256});
if (0 == getentropy(buf, getentropy_nbytes)) {
actual_nbytes = getentropy_nbytes;
}
#endif
if (actual_nbytes == -1) {
static const int fd =
WHILE_EINTR(open("/dev/urandom", O_RDONLY | O_CLOEXEC, 0));
if (fd != -1) {
// ###FIXME: Why is this locked? None of the others are.
static LazyMutex mutex;
mutex.withLock([&] {
actual_nbytes = WHILE_EINTR(read(fd, buf, nbytes));
});
}
}
if (actual_nbytes == -1) {
fatalError(0, "Fatal error: %d in '%s'\n", errno, __func__);
}
buf = static_cast<uint8_t *>(buf) + actual_nbytes;
nbytes -= actual_nbytes;
}
}
#endif