1 //===-- scudo_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 /// Header for scudo_utils.cpp.
11 ///
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef SCUDO_UTILS_H_
15 #define SCUDO_UTILS_H_
16 
17 #include <string.h>
18 
19 #include "sanitizer_common/sanitizer_common.h"
20 
21 namespace __scudo {
22 
23 template <class Dest, class Source>
bit_cast(const Source & source)24 inline Dest bit_cast(const Source& source) {
25   static_assert(sizeof(Dest) == sizeof(Source), "Sizes are not equal!");
26   Dest dest;
27   memcpy(&dest, &source, sizeof(dest));
28   return dest;
29 }
30 
31 void dieWithMessage(const char *Format, ...);
32 
33 enum  CPUFeature {
34   SSE4_2 = 0,
35   ENUM_CPUFEATURE_MAX
36 };
37 bool testCPUFeature(CPUFeature feature);
38 
39 // Tiny PRNG based on https://en.wikipedia.org/wiki/Xorshift#xorshift.2B
40 // The state (128 bits) will be stored in thread local storage.
41 struct Xorshift128Plus {
42  public:
43   Xorshift128Plus();
NextXorshift128Plus44   u64 Next() {
45     u64 x = State_0_;
46     const u64 y = State_1_;
47     State_0_ = y;
48     x ^= x << 23;
49     State_1_ = x ^ y ^ (x >> 17) ^ (y >> 26);
50     return State_1_ + y;
51   }
52  private:
53   u64 State_0_;
54   u64 State_1_;
55 };
56 
57 } // namespace __scudo
58 
59 #endif  // SCUDO_UTILS_H_
60