add libfuzzer custom mutator, minor enhancements and fixes

custom_mutators/libfuzzer/FuzzerIOPosix.cpp

@@ -0,0 +1,223 @@
+//===- FuzzerIOPosix.cpp - IO utils for Posix. ----------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+// IO functions implementation using Posix API.
+//===----------------------------------------------------------------------===//
+#include "FuzzerPlatform.h"
+#if LIBFUZZER_POSIX || LIBFUZZER_FUCHSIA
+
+  #include "FuzzerExtFunctions.h"
+  #include "FuzzerIO.h"
+  #include <cstdarg>
+  #include <cstdio>
+  #include <dirent.h>
+  #include <fstream>
+  #include <iterator>
+  #include <libgen.h>
+  #include <sys/stat.h>
+  #include <sys/types.h>
+  #include <unistd.h>
+
+namespace fuzzer {
+
+bool IsFile(const std::string &Path) {
+
+  struct stat St;
+  if (stat(Path.c_str(), &St)) return false;
+  return S_ISREG(St.st_mode);
+
+}
+
+bool IsDirectory(const std::string &Path) {
+
+  struct stat St;
+  if (stat(Path.c_str(), &St)) return false;
+  return S_ISDIR(St.st_mode);
+
+}
+
+size_t FileSize(const std::string &Path) {
+
+  struct stat St;
+  if (stat(Path.c_str(), &St)) return 0;
+  return St.st_size;
+
+}
+
+std::string Basename(const std::string &Path) {
+
+  size_t Pos = Path.rfind(GetSeparator());
+  if (Pos == std::string::npos) return Path;
+  assert(Pos < Path.size());
+  return Path.substr(Pos + 1);
+
+}
+
+void ListFilesInDirRecursive(const std::string &Dir, long *Epoch,
+                             Vector<std::string> *V, bool TopDir) {
+
+  auto E = GetEpoch(Dir);
+  if (Epoch)
+    if (E && *Epoch >= E) return;
+
+  DIR *D = opendir(Dir.c_str());
+  if (!D) {
+
+    Printf("%s: %s; exiting\n", strerror(errno), Dir.c_str());
+    exit(1);
+
+  }
+
+  while (auto E = readdir(D)) {
+
+    std::string Path = DirPlusFile(Dir, E->d_name);
+    if (E->d_type == DT_REG || E->d_type == DT_LNK ||
+        (E->d_type == DT_UNKNOWN && IsFile(Path)))
+      V->push_back(Path);
+    else if ((E->d_type == DT_DIR ||
+              (E->d_type == DT_UNKNOWN && IsDirectory(Path))) &&
+             *E->d_name != '.')
+      ListFilesInDirRecursive(Path, Epoch, V, false);
+
+  }
+
+  closedir(D);
+  if (Epoch && TopDir) *Epoch = E;
+
+}
+
+void IterateDirRecursive(const std::string &Dir,
+                         void (*DirPreCallback)(const std::string &Dir),
+                         void (*DirPostCallback)(const std::string &Dir),
+                         void (*FileCallback)(const std::string &Dir)) {
+
+  DirPreCallback(Dir);
+  DIR *D = opendir(Dir.c_str());
+  if (!D) return;
+  while (auto E = readdir(D)) {
+
+    std::string Path = DirPlusFile(Dir, E->d_name);
+    if (E->d_type == DT_REG || E->d_type == DT_LNK ||
+        (E->d_type == DT_UNKNOWN && IsFile(Path)))
+      FileCallback(Path);
+    else if ((E->d_type == DT_DIR ||
+              (E->d_type == DT_UNKNOWN && IsDirectory(Path))) &&
+             *E->d_name != '.')
+      IterateDirRecursive(Path, DirPreCallback, DirPostCallback, FileCallback);
+
+  }
+
+  closedir(D);
+  DirPostCallback(Dir);
+
+}
+
+char GetSeparator() {
+
+  return '/';
+
+}
+
+bool IsSeparator(char C) {
+
+  return C == '/';
+
+}
+
+FILE *OpenFile(int Fd, const char *Mode) {
+
+  return fdopen(Fd, Mode);
+
+}
+
+int CloseFile(int fd) {
+
+  return close(fd);
+
+}
+
+int DuplicateFile(int Fd) {
+
+  return dup(Fd);
+
+}
+
+void RemoveFile(const std::string &Path) {
+
+  unlink(Path.c_str());
+
+}
+
+void RenameFile(const std::string &OldPath, const std::string &NewPath) {
+
+  rename(OldPath.c_str(), NewPath.c_str());
+
+}
+
+intptr_t GetHandleFromFd(int fd) {
+
+  return static_cast<intptr_t>(fd);
+
+}
+
+std::string DirName(const std::string &FileName) {
+
+  char *Tmp = new char[FileName.size() + 1];
+  memcpy(Tmp, FileName.c_str(), FileName.size() + 1);
+  std::string Res = dirname(Tmp);
+  delete[] Tmp;
+  return Res;
+
+}
+
+std::string TmpDir() {
+
+  if (auto Env = getenv("TMPDIR")) return Env;
+  return "/tmp";
+
+}
+
+bool IsInterestingCoverageFile(const std::string &FileName) {
+
+  if (FileName.find("compiler-rt/lib/") != std::string::npos)
+    return false;  // sanitizer internal.
+  if (FileName.find("/usr/lib/") != std::string::npos) return false;
+  if (FileName.find("/usr/include/") != std::string::npos) return false;
+  if (FileName == "<null>") return false;
+  return true;
+
+}
+
+void RawPrint(const char *Str) {
+
+  write(2, Str, strlen(Str));
+
+}
+
+void MkDir(const std::string &Path) {
+
+  mkdir(Path.c_str(), 0700);
+
+}
+
+void RmDir(const std::string &Path) {
+
+  rmdir(Path.c_str());
+
+}
+
+const std::string &getDevNull() {
+
+  static const std::string devNull = "/dev/null";
+  return devNull;
+
+}
+
+}  // namespace fuzzer
+
+#endif  // LIBFUZZER_POSIX
+