1
0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-25 12:12:47 +01:00
llvm-mirror/lib/Support/RandomNumberGenerator.cpp
Nicola Zaghen 9667127c14 Rename DEBUG macro to LLVM_DEBUG.
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM
- Manual change to APInt
- Manually chage DOCS as regex doesn't match it.

In the transition period the DEBUG() macro is still present and aliased
to the LLVM_DEBUG() one.

Differential Revision: https://reviews.llvm.org/D43624

llvm-svn: 332240
2018-05-14 12:53:11 +00:00

90 lines
3.0 KiB
C++

//===-- RandomNumberGenerator.cpp - Implement RNG class -------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements deterministic random number generation (RNG).
// The current implementation is NOT cryptographically secure as it uses
// the C++11 <random> facilities.
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/RandomNumberGenerator.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#ifdef _WIN32
#include "Windows/WindowsSupport.h"
#else
#include "Unix/Unix.h"
#endif
using namespace llvm;
#define DEBUG_TYPE "rng"
// Tracking BUG: 19665
// http://llvm.org/bugs/show_bug.cgi?id=19665
//
// Do not change to cl::opt<uint64_t> since this silently breaks argument parsing.
static cl::opt<unsigned long long>
Seed("rng-seed", cl::value_desc("seed"), cl::Hidden,
cl::desc("Seed for the random number generator"), cl::init(0));
RandomNumberGenerator::RandomNumberGenerator(StringRef Salt) {
LLVM_DEBUG(if (Seed == 0) dbgs()
<< "Warning! Using unseeded random number generator.\n");
// Combine seed and salts using std::seed_seq.
// Data: Seed-low, Seed-high, Salt
// Note: std::seed_seq can only store 32-bit values, even though we
// are using a 64-bit RNG. This isn't a problem since the Mersenne
// twister constructor copies these correctly into its initial state.
std::vector<uint32_t> Data;
Data.resize(2 + Salt.size());
Data[0] = Seed;
Data[1] = Seed >> 32;
std::copy(Salt.begin(), Salt.end(), Data.begin() + 2);
std::seed_seq SeedSeq(Data.begin(), Data.end());
Generator.seed(SeedSeq);
}
RandomNumberGenerator::result_type RandomNumberGenerator::operator()() {
return Generator();
}
// Get random vector of specified size
std::error_code llvm::getRandomBytes(void *Buffer, size_t Size) {
#ifdef _WIN32
HCRYPTPROV hProvider;
if (CryptAcquireContext(&hProvider, 0, 0, PROV_RSA_FULL,
CRYPT_VERIFYCONTEXT | CRYPT_SILENT)) {
ScopedCryptContext ScopedHandle(hProvider);
if (CryptGenRandom(hProvider, Size, static_cast<BYTE *>(Buffer)))
return std::error_code();
}
return std::error_code(GetLastError(), std::system_category());
#else
int Fd = open("/dev/urandom", O_RDONLY);
if (Fd != -1) {
std::error_code Ret;
ssize_t BytesRead = read(Fd, Buffer, Size);
if (BytesRead == -1)
Ret = std::error_code(errno, std::system_category());
else if (BytesRead != static_cast<ssize_t>(Size))
Ret = std::error_code(EIO, std::system_category());
if (close(Fd) == -1)
Ret = std::error_code(errno, std::system_category());
return Ret;
}
return std::error_code(errno, std::system_category());
#endif
}