1 //===-- xray_utils.h --------------------------------------------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file is a part of XRay, a dynamic runtime instrumentation system. 11 // 12 // Some shared utilities for the XRay runtime implementation. 13 // 14 //===----------------------------------------------------------------------===// 15 #ifndef XRAY_UTILS_H 16 #define XRAY_UTILS_H 17 18 #include <cstddef> 19 #include <cstdint> 20 #include <sys/types.h> 21 #include <utility> 22 23 #include "sanitizer_common/sanitizer_common.h" 24 #if SANITIZER_FUCHSIA 25 #include <zircon/types.h> 26 #endif 27 28 namespace __xray { 29 30 class LogWriter { 31 public: 32 #if SANITIZER_FUCHSIA 33 LogWriter(zx_handle_t Vmo) : Vmo(Vmo) {} 34 #else 35 explicit LogWriter(int Fd) : Fd(Fd) {} 36 #endif 37 ~LogWriter(); 38 39 // Write a character range into a log. 40 void WriteAll(const char *Begin, const char *End); 41 42 void Flush(); 43 44 // Returns a new log instance initialized using the flag-provided values. 45 static LogWriter *Open(); 46 // Closes and deallocates the log instance. 47 static void Close(LogWriter *LogWriter); 48 49 private: 50 #if SANITIZER_FUCHSIA 51 zx_handle_t Vmo = ZX_HANDLE_INVALID; 52 uint64_t Offset = 0; 53 #else 54 int Fd = -1; 55 #endif 56 }; 57 58 constexpr size_t gcd(size_t a, size_t b) { 59 return (b == 0) ? a : gcd(b, a % b); 60 } 61 62 constexpr size_t lcm(size_t a, size_t b) { return a * b / gcd(a, b); } 63 64 constexpr size_t nearest_boundary(size_t number, size_t multiple) { 65 return multiple * ((number / multiple) + (number % multiple ? 1 : 0)); 66 } 67 68 constexpr size_t next_pow2_helper(size_t num, size_t acc) { 69 return (1u << acc) >= num ? (1u << acc) : next_pow2_helper(num, acc + 1); 70 } 71 72 constexpr size_t next_pow2(size_t number) { 73 return next_pow2_helper(number, 1); 74 } 75 76 template <class T> constexpr T &max(T &A, T &B) { return A > B ? A : B; } 77 78 template <class T> constexpr T &min(T &A, T &B) { return A <= B ? A : B; } 79 80 constexpr ptrdiff_t diff(uintptr_t A, uintptr_t B) { 81 return max(A, B) - min(A, B); 82 } 83 84 } // namespace __xray 85 86 #endif // XRAY_UTILS_H 87