add libfuzzer custom mutator, minor enhancements and fixes

custom_mutators/libfuzzer/FuzzerUtil.h

@@ -0,0 +1,117 @@
+//===- FuzzerUtil.h - Internal header for the Fuzzer Utils ------*- C++ -* ===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+// Util functions.
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_FUZZER_UTIL_H
+#define LLVM_FUZZER_UTIL_H
+
+#include "FuzzerBuiltins.h"
+#include "FuzzerBuiltinsMsvc.h"
+#include "FuzzerCommand.h"
+#include "FuzzerDefs.h"
+
+namespace fuzzer {
+
+void PrintHexArray(const Unit &U, const char *PrintAfter = "");
+
+void PrintHexArray(const uint8_t *Data, size_t Size,
+                   const char *PrintAfter = "");
+
+void PrintASCII(const uint8_t *Data, size_t Size, const char *PrintAfter = "");
+
+void PrintASCII(const Unit &U, const char *PrintAfter = "");
+
+// Changes U to contain only ASCII (isprint+isspace) characters.
+// Returns true iff U has been changed.
+bool ToASCII(uint8_t *Data, size_t Size);
+
+bool IsASCII(const Unit &U);
+
+bool IsASCII(const uint8_t *Data, size_t Size);
+
+std::string Base64(const Unit &U);
+
+void PrintPC(const char *SymbolizedFMT, const char *FallbackFMT, uintptr_t PC);
+
+std::string DescribePC(const char *SymbolizedFMT, uintptr_t PC);
+
+void PrintStackTrace();
+
+void PrintMemoryProfile();
+
+unsigned NumberOfCpuCores();
+
+// Platform specific functions.
+void SetSignalHandler(const FuzzingOptions& Options);
+
+void SleepSeconds(int Seconds);
+
+unsigned long GetPid();
+
+size_t GetPeakRSSMb();
+
+int ExecuteCommand(const Command &Cmd);
+bool ExecuteCommand(const Command &Cmd, std::string *CmdOutput);
+
+// Fuchsia does not have popen/pclose.
+FILE *OpenProcessPipe(const char *Command, const char *Mode);
+int CloseProcessPipe(FILE *F);
+
+const void *SearchMemory(const void *haystack, size_t haystacklen,
+                         const void *needle, size_t needlelen);
+
+std::string CloneArgsWithoutX(const Vector<std::string> &Args,
+                              const char *X1, const char *X2);
+
+inline std::string CloneArgsWithoutX(const Vector<std::string> &Args,
+                                     const char *X) {
+  return CloneArgsWithoutX(Args, X, X);
+}
+
+inline std::pair<std::string, std::string> SplitBefore(std::string X,
+                                                       std::string S) {
+  auto Pos = S.find(X);
+  if (Pos == std::string::npos)
+    return std::make_pair(S, "");
+  return std::make_pair(S.substr(0, Pos), S.substr(Pos));
+}
+
+void DiscardOutput(int Fd);
+
+std::string DisassembleCmd(const std::string &FileName);
+
+std::string SearchRegexCmd(const std::string &Regex);
+
+size_t SimpleFastHash(const uint8_t *Data, size_t Size);
+
+inline uint32_t Log(uint32_t X) { return 32 - Clz(X) - 1; }
+
+inline size_t PageSize() { return 4096; }
+inline uint8_t *RoundUpByPage(uint8_t *P) {
+  uintptr_t X = reinterpret_cast<uintptr_t>(P);
+  size_t Mask = PageSize() - 1;
+  X = (X + Mask) & ~Mask;
+  return reinterpret_cast<uint8_t *>(X);
+}
+inline uint8_t *RoundDownByPage(uint8_t *P) {
+  uintptr_t X = reinterpret_cast<uintptr_t>(P);
+  size_t Mask = PageSize() - 1;
+  X = X & ~Mask;
+  return reinterpret_cast<uint8_t *>(X);
+}
+
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+template <typename T> T HostToLE(T X) { return X; }
+#else
+template <typename T> T HostToLE(T X) { return Bswap(X); }
+#endif
+
+}  // namespace fuzzer
+
+#endif  // LLVM_FUZZER_UTIL_H