[libFuzzer] Portable implementation of `IsInterestingCoverageFile()`.

[zturner]

Looks ok to me.

llvm/trunk/lib/Fuzzer/FuzzerIO.h

std::string DirPlusFile(const std::string &DirPath,
                         const std::string &FileName);
 
 // Returns the name of the dir, similar to the 'dirname' utility.
 std::string DirName(const std::string &FileName);
 
 // Returns path to a TmpDir.
 std::string TmpDir();
 
+bool IsInterestingCoverageFile(const std::string &FileName);
+
 void DupAndCloseStderr();
 
 void CloseStdout();
 
 void Printf(const char *Fmt, ...);
 
 // Platform specific functions:
 bool IsFile(const std::string &Path);

llvm/trunk/lib/Fuzzer/FuzzerIOPosix.cpp

 }
 
 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;
+}
+
 }  // namespace fuzzer
 
 #endif // LIBFUZZER_POSIX

llvm/trunk/lib/Fuzzer/FuzzerIOWindows.cpp

if (!LocationLen) { // Relative path.
     return std::string(".\\").append(FileName, 0, DirLen);
   }
 
   return FileName.substr(0, LocationLen + DirLen);
 }
 
 std::string TmpDir() { return "TODO: implement TmpDir"; }
 
+bool IsInterestingCoverageFile(const std::string &FileName) {
+  if (FileName.find("Program Files") != std::string::npos)
+    return false;
+  if (FileName.find("compiler-rt\\lib\\") != std::string::npos)
+    return false; // sanitizer internal.
+  if (FileName == "<null>")
+    return false;
+  return true;
+}
+
 }  // namespace fuzzer
 
 #endif // LIBFUZZER_WINDOWS

llvm/trunk/lib/Fuzzer/FuzzerTracePC.cpp

 
 void TracePC::HandleCallerCallee(uintptr_t Caller, uintptr_t Callee) {
   const uintptr_t kBits = 12;
   const uintptr_t kMask = (1 << kBits) - 1;
   uintptr_t Idx = (Caller & kMask) | ((Callee & kMask) << kBits);
   HandleValueProfile(Idx);
 }
 
-static bool IsInterestingCoverageFile(std::string &File) {
-  if (File.find("compiler-rt/lib/") != std::string::npos)
-    return false; // sanitizer internal.
-  if (File.find("/usr/lib/") != std::string::npos)
-    return false;
-  if (File.find("/usr/include/") != std::string::npos)
-    return false;
-  if (File == "<null>")
-    return false;
-  return true;
-}
-
 void TracePC::InitializePrintNewPCs() {
   if (!DoPrintNewPCs) return;
   assert(!PrintedPCs);
   PrintedPCs = new std::set<uintptr_t>;
   for (size_t i = 1; i < GetNumPCs(); i++)
     if (PCs[i])
       PrintedPCs->insert(PCs[i]);
 }