diff --git a/runtime/dex_file.cc b/runtime/dex_file.cc
index e5bc7c8..e1a7771 100644
--- a/runtime/dex_file.cc
+++ b/runtime/dex_file.cc
@@ -951,6 +951,38 @@
   return std::make_pair(tmp, colon_ptr + 1);
 }
 
+std::string DexFile::GetMultiDexClassesDexName(size_t number, const char* dex_location) {
+  if (number == 0) {
+    return dex_location;
+  } else {
+    return StringPrintf("%s" kMultiDexSeparatorString "classes%zu.dex", dex_location, number + 1);
+  }
+}
+
+std::string DexFile::GetDexCanonicalLocation(const char* dex_location) {
+  CHECK_NE(dex_location, static_cast<const char*>(nullptr));
+  char* path = nullptr;
+  if (!IsMultiDexLocation(dex_location)) {
+    path = realpath(dex_location, nullptr);
+  } else {
+    std::pair<const char*, const char*> pair = DexFile::SplitMultiDexLocation(dex_location);
+    const char* dex_real_location(realpath(pair.first, nullptr));
+    delete pair.first;
+    if (dex_real_location != nullptr) {
+      int length = strlen(dex_real_location) + strlen(pair.second) + strlen(kMultiDexSeparatorString) + 1;
+      char* multidex_canonical_location = reinterpret_cast<char*>(malloc(sizeof(char) * length));
+      snprintf(multidex_canonical_location, length, "%s" kMultiDexSeparatorString "%s", dex_real_location, pair.second);
+      free(const_cast<char*>(dex_real_location));
+      path = multidex_canonical_location;
+    }
+  }
+
+  // If realpath fails then we just copy the argument.
+  std::string result(path == nullptr ? dex_location : path);
+  free(path);
+  return result;
+}
+
 std::ostream& operator<<(std::ostream& os, const DexFile& dex_file) {
   os << StringPrintf("[DexFile: %s dex-checksum=%08x location-checksum=%08x %p-%p]",
                      dex_file.GetLocation().c_str(),
@@ -958,6 +990,7 @@
                      dex_file.Begin(), dex_file.Begin() + dex_file.Size());
   return os;
 }
+
 std::string Signature::ToString() const {
   if (dex_file_ == nullptr) {
     CHECK(proto_id_ == nullptr);