diff --git a/src/clang_complete.h b/src/clang_complete.h
index d9874c91..8633ddce 100644
--- a/src/clang_complete.h
+++ b/src/clang_complete.h
@@ -8,8 +8,6 @@
 #include "threaded_queue.h"
 #include "working_files.h"
 
-#include <clang-c/Index.h>
-
 #include <functional>
 #include <memory>
 #include <mutex>
diff --git a/src/clang_utils.cc b/src/clang_utils.cc
index d1d141ea..8e0b1125 100644
--- a/src/clang_utils.cc
+++ b/src/clang_utils.cc
@@ -1,30 +1,14 @@
 #include "clang_utils.h"
 
+#include "config.h"
 #include "filesystem.hh"
 #include "platform.h"
+#include "utils.h"
 
 #include <clang/AST/Type.h>
 using namespace clang;
 using namespace llvm;
 
-std::string FileName(CXFile file) {
-  std::string ret;
-  // clang > 6
-#if CINDEX_VERSION >= 48
-  ret = ToString(clang_File_tryGetRealPathName(file));
-#endif
-  if (ret.empty())
-    // clang_getFileName return values may contain ..
-    ret = NormalizePath(ToString(clang_getFileName(file)));
-  // Resolve /usr/include/c++/7.3.0 symlink.
-  if (!StartsWith(ret, g_config->projectRoot)) {
-    SmallString<256> dest;
-    sys::fs::real_path(ret, dest);
-    ret = dest.str();
-  }
-  return ret;
-}
-
 std::string FileName(const FileEntry& file) {
   StringRef Name = file.tryGetRealPathName();
   if (Name.empty())
@@ -39,19 +23,6 @@ std::string FileName(const FileEntry& file) {
   return ret;
 }
 
-std::string ToString(CXString cx_string) {
-  std::string string;
-  if (cx_string.data != nullptr) {
-    string = clang_getCString(cx_string);
-    clang_disposeString(cx_string);
-  }
-  return string;
-}
-
-std::string ToString(CXCursorKind kind) {
-  return ToString(clang_getCursorKindSpelling(kind));
-}
-
 // clang::BuiltinType::getName without PrintingPolicy
 const char* ClangBuiltinTypeName(int kind) {
   switch (BuiltinType::Kind(kind)) {
diff --git a/src/clang_utils.h b/src/clang_utils.h
index 7f52eded..6bf5d04e 100644
--- a/src/clang_utils.h
+++ b/src/clang_utils.h
@@ -1,19 +1,10 @@
 #pragma once
 
-#include "lsp_diagnostic.h"
-
-#include <clang-c/Index.h>
 #include <clang/Basic/FileManager.h>
 
-#include <optional>
-#include <vector>
+#include <string>
 
 // Returns the absolute path to |file|.
-std::string FileName(CXFile file);
 std::string FileName(const clang::FileEntry& file);
 
-std::string ToString(CXString cx_string);
-
-std::string ToString(CXCursorKind cursor_kind);
-
 const char* ClangBuiltinTypeName(int);
diff --git a/src/file_consumer.h b/src/file_consumer.h
index a2ec0129..2dcb9622 100644
--- a/src/file_consumer.h
+++ b/src/file_consumer.h
@@ -4,7 +4,6 @@
 #include "serializer.h"
 #include "utils.h"
 
-#include <clang-c/Index.h>
 #include <clang/Basic/FileManager.h>
 
 #include <mutex>
diff --git a/src/indexer.cc b/src/indexer.cc
index 505d1ea0..60aad85f 100644
--- a/src/indexer.cc
+++ b/src/indexer.cc
@@ -6,6 +6,7 @@
 #include "serializer.h"
 using ccls::Intern;
 
+#include <clang-c/Index.h>
 #include <clang/AST/AST.h>
 #include <clang/Frontend/ASTUnit.h>
 #include <clang/Frontend/CompilerInstance.h>
@@ -777,7 +778,7 @@ public:
     }
       [[fallthrough]];
     case Decl::Record: {
-      auto *RD = cast<RecordDecl>(OrigD);
+      auto *RD = cast<RecordDecl>(D);
       // spec has no Union, use Class
       type->def.kind = RD->getTagKind() == TTK_Struct ? lsSymbolKind::Struct
                                                       : lsSymbolKind::Class;
diff --git a/src/indexer.h b/src/indexer.h
index 7d2bc137..0e925e85 100644
--- a/src/indexer.h
+++ b/src/indexer.h
@@ -4,6 +4,7 @@
 #include "file_consumer.h"
 #include "language.h"
 #include "lsp.h"
+#include "lsp_diagnostic.h"
 #include "maybe.h"
 #include "position.h"
 #include "serializer.h"
diff --git a/src/messages/ccls_memberHierarchy.cc b/src/messages/ccls_memberHierarchy.cc
index 653b773d..e40244c4 100644
--- a/src/messages/ccls_memberHierarchy.cc
+++ b/src/messages/ccls_memberHierarchy.cc
@@ -125,7 +125,7 @@ bool Expand(MessageHandler* m,
             bool qualified,
             int levels) {
   if (0 < entry->usr && entry->usr <= BuiltinType::LastKind) {
-    entry->name = ClangBuiltinTypeName(CXTypeKind(entry->usr));
+    entry->name = ClangBuiltinTypeName(int(entry->usr));
     return true;
   }
   const QueryType& type = m->db->Type(entry->usr);
diff --git a/src/test.cc b/src/test.cc
index cade7314..83ba466c 100644
--- a/src/test.cc
+++ b/src/test.cc
@@ -6,6 +6,8 @@
 #include "serializer.h"
 #include "utils.h"
 
+#include <llvm/Config/llvm-config.h>
+
 #include <rapidjson/document.h>
 #include <rapidjson/prettywriter.h>
 #include <rapidjson/stringbuffer.h>
@@ -227,13 +229,12 @@ IndexFile* FindDbForPathEnding(
 
 bool RunIndexTests(const std::string& filter_path, bool enable_update) {
   gTestOutputMode = true;
-  std::string version = ToString(clang_getClangVersion());
+  std::string version = LLVM_VERSION_STRING;
 
   // Index tests change based on the version of clang used.
-  static const char kRequiredClangVersion[] =
-      "clang version 6.0.0 (tags/RELEASE_600/final)";
+  static const char kRequiredClangVersion[] = "6.0.0";
   if (version != kRequiredClangVersion &&
-      version.find("trunk") == std::string::npos) {
+      version.find("svn") == std::string::npos) {
     fprintf(stderr,
             "Index tests must be run using clang version %s, ccls is running "
             "with %s\n",
diff --git a/src/working_files.h b/src/working_files.h
index d5a960ac..a1758b74 100644
--- a/src/working_files.h
+++ b/src/working_files.h
@@ -3,10 +3,8 @@
 #include "lsp_diagnostic.h"
 #include "utils.h"
 
-#include <clang-c/Index.h>
-#include <optional>
-
 #include <mutex>
+#include <optional>
 #include <string>
 
 struct WorkingFile {