//===-- xray_utils.h --------------------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file is a part of XRay, a dynamic runtime instrumentation system.
//
// Some shared utilities for the XRay runtime implementation.
//
//===----------------------------------------------------------------------===//
#ifndef XRAY_UTILS_H
#define XRAY_UTILS_H

#include <cstddef>
#include <cstdint>
#include <sys/types.h>
#include <utility>

namespace __xray {

// Default implementation of the reporting interface for sanitizer errors.
void printToStdErr(const char *Buffer);

// EINTR-safe write routine, provided a file descriptor and a character range.
void retryingWriteAll(int Fd, const char *Begin, const char *End);

// Reads a long long value from a provided file.
bool readValueFromFile(const char *Filename, long long *Value);

// EINTR-safe read routine, providing a file descriptor and a character range.
std::pair<ssize_t, bool> retryingReadSome(int Fd, char *Begin, char *End);

// EINTR-safe open routine, uses flag-provided values for initialising a log
// file.
int getLogFD();

constexpr size_t gcd(size_t a, size_t b) {
  return (b == 0) ? a : gcd(b, a % b);
}

constexpr size_t lcm(size_t a, size_t b) { return a * b / gcd(a, b); }

constexpr size_t nearest_boundary(size_t number, size_t multiple) {
  return multiple * ((number / multiple) + (number % multiple ? 1 : 0));
}

constexpr size_t next_pow2_helper(size_t num, size_t acc) {
  return (1u << acc) >= num ? (1u << acc) : next_pow2_helper(num, acc + 1);
}

constexpr size_t next_pow2(size_t number) {
  return next_pow2_helper(number, 1);
}

template <class T> constexpr T &max(T &A, T &B) { return A > B ? A : B; }

template <class T> constexpr T &min(T &A, T &B) { return A <= B ? A : B; }

constexpr ptrdiff_t diff(uintptr_t A, uintptr_t B) {
  return max(A, B) - min(A, B);
}

} // namespace __xray

#endif // XRAY_UTILS_H