diff --git a/CMakeLists.txt b/CMakeLists.txt
index e3364e3b..0e77fcd8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -96,6 +96,11 @@ set(THREADS_PREFER_PTHREAD_FLAG ON)
 find_package(Threads REQUIRED)
 target_link_libraries(ccls PRIVATE Threads::Threads)
 
+if(${CMAKE_SYSTEM_NAME} MATCHES "Windows")
+else()
+  target_link_libraries(ccls PRIVATE -lstdc++fs)
+endif()
+
 if(${CMAKE_SYSTEM_NAME} STREQUAL Linux)
   # loguru calls dladdr
   target_link_libraries(ccls PRIVATE ${CMAKE_DL_LIBS})
@@ -233,7 +238,6 @@ target_sources(ccls PRIVATE
                src/messages/text_document_did_open.cc
                src/messages/text_document_did_save.cc
                src/messages/text_document_document_highlight.cc
-               src/messages/text_document_document_link.cc
                src/messages/text_document_document_symbol.cc
                src/messages/text_document_hover.cc
                src/messages/text_document_references.cc
diff --git a/src/filesystem.hh b/src/filesystem.hh
new file mode 100644
index 00000000..0608bd71
--- /dev/null
+++ b/src/filesystem.hh
@@ -0,0 +1,5 @@
+#pragma once
+
+#include <experimental/filesystem>
+
+namespace fs = std::experimental::filesystem;
diff --git a/src/lex_utils.cc b/src/lex_utils.cc
index 5d66adf0..cb3ad0f5 100644
--- a/src/lex_utils.cc
+++ b/src/lex_utils.cc
@@ -24,116 +24,6 @@ int GetOffsetForPosition(lsPosition position, std::string_view content) {
   return int(i);
 }
 
-// TODO: eliminate |line_number| param.
-std::optional<lsRange> ExtractQuotedRange(int line_number, const std::string& line) {
-  // Find starting and ending quote.
-  int start = 0;
-  while (start < (int)line.size()) {
-    char c = line[start];
-    ++start;
-    if (c == '"' || c == '<')
-      break;
-  }
-  if (start == (int)line.size())
-    return std::nullopt;
-
-  int end = (int)line.size();
-  while (end > 0) {
-    char c = line[end];
-    if (c == '"' || c == '>')
-      break;
-    --end;
-  }
-
-  if (start >= end)
-    return std::nullopt;
-
-  return lsRange(lsPosition(line_number, start), lsPosition(line_number, end));
-}
-
-void LexFunctionDeclaration(const std::string& buffer_content,
-                            lsPosition declaration_spelling,
-                            std::optional<std::string> type_name,
-                            std::string* insert_text,
-                            int* newlines_after_name) {
-  int name_start = GetOffsetForPosition(declaration_spelling, buffer_content);
-
-  bool parse_return_type = true;
-  // We need to check if we have a return type (ctors and dtors do not).
-  if (type_name) {
-    int name_end = name_start;
-    while (name_end < buffer_content.size()) {
-      char c = buffer_content[name_end];
-      if (isspace(c) || c == '(')
-        break;
-      ++name_end;
-    }
-
-    std::string func_name =
-        buffer_content.substr(name_start, name_end - name_start);
-    if (func_name == *type_name || func_name == ("~" + *type_name))
-      parse_return_type = false;
-  }
-
-  // We need to fetch the return type. This can get complex, ie,
-  //
-  //  std::vector <int> foo();
-  //
-  int return_start = name_start;
-  if (parse_return_type) {
-    int paren_balance = 0;
-    int angle_balance = 0;
-    bool expect_token = true;
-    while (return_start > 0) {
-      char c = buffer_content[return_start - 1];
-      if (paren_balance == 0 && angle_balance == 0) {
-        if (isspace(c) && !expect_token) {
-          break;
-        }
-        if (!isspace(c))
-          expect_token = false;
-      }
-
-      if (c == ')')
-        ++paren_balance;
-      if (c == '(') {
-        --paren_balance;
-        expect_token = true;
-      }
-
-      if (c == '>')
-        ++angle_balance;
-      if (c == '<') {
-        --angle_balance;
-        expect_token = true;
-      }
-
-      return_start -= 1;
-    }
-  }
-
-  // We need to fetch the arguments. Just scan for the next ';'.
-  *newlines_after_name = 0;
-  int end = name_start;
-  while (end < buffer_content.size()) {
-    char c = buffer_content[end];
-    if (c == ';')
-      break;
-    if (c == '\n')
-      *newlines_after_name += 1;
-    ++end;
-  }
-
-  std::string result;
-  result += buffer_content.substr(return_start, name_start - return_start);
-  if (type_name && !type_name->empty())
-    result += *type_name + "::";
-  result += buffer_content.substr(name_start, end - name_start);
-  TrimEndInPlace(result);
-  result += " {\n}";
-  *insert_text = result;
-}
-
 std::string_view LexIdentifierAroundPos(lsPosition position,
                                         std::string_view content) {
   int start = GetOffsetForPosition(position, content);
diff --git a/src/lex_utils.h b/src/lex_utils.h
index 36328ad3..13d6a043 100644
--- a/src/lex_utils.h
+++ b/src/lex_utils.h
@@ -3,22 +3,11 @@
 #include "lsp.h"
 
 #include <string_view>
-
-#include <string>
 #include <tuple>
 
 // Utility method to map |position| to an offset inside of |content|.
 int GetOffsetForPosition(lsPosition position, std::string_view content);
 
-// TODO: eliminate |line_number| param.
-std::optional<lsRange> ExtractQuotedRange(int line_number, const std::string& line);
-
-void LexFunctionDeclaration(const std::string& buffer_content,
-                            lsPosition declaration_spelling,
-                            std::optional<std::string> type_name,
-                            std::string* insert_text,
-                            int* newlines_after_name);
-
 std::string_view LexIdentifierAroundPos(lsPosition position,
                                         std::string_view content);
 
diff --git a/src/messages/text_document_document_link.cc b/src/messages/text_document_document_link.cc
deleted file mode 100644
index b44639df..00000000
--- a/src/messages/text_document_document_link.cc
+++ /dev/null
@@ -1,85 +0,0 @@
-#include "lex_utils.h"
-#include "message_handler.h"
-#include "queue_manager.h"
-#include "working_files.h"
-
-#include <loguru.hpp>
-
-namespace {
-MethodType kMethodType = "textDocument/documentLink";
-
-struct In_TextDocumentDocumentLink : public RequestInMessage {
-  MethodType GetMethodType() const override { return kMethodType; }
-  struct Params {
-    // The document to provide document links for.
-    lsTextDocumentIdentifier textDocument;
-  };
-  Params params;
-};
-MAKE_REFLECT_STRUCT(In_TextDocumentDocumentLink::Params, textDocument);
-MAKE_REFLECT_STRUCT(In_TextDocumentDocumentLink, id, params);
-REGISTER_IN_MESSAGE(In_TextDocumentDocumentLink);
-
-// A document link is a range in a text document that links to an internal or
-// external resource, like another text document or a web site.
-struct lsDocumentLink {
-  // The range this link applies to.
-  lsRange range;
-  // The uri this link points to. If missing a resolve request is sent later.
-  std::optional<lsDocumentUri> target;
-};
-MAKE_REFLECT_STRUCT(lsDocumentLink, range, target);
-
-struct Out_TextDocumentDocumentLink
-    : public lsOutMessage<Out_TextDocumentDocumentLink> {
-  lsRequestId id;
-  std::vector<lsDocumentLink> result;
-};
-MAKE_REFLECT_STRUCT(Out_TextDocumentDocumentLink, jsonrpc, id, result);
-
-struct Handler_TextDocumentDocumentLink
-    : BaseMessageHandler<In_TextDocumentDocumentLink> {
-  MethodType GetMethodType() const override { return kMethodType; }
-  void Run(In_TextDocumentDocumentLink* request) override {
-    Out_TextDocumentDocumentLink out;
-    out.id = request->id;
-
-    if (config->showDocumentLinksOnIncludes) {
-      QueryFile* file;
-      if (!FindFileOrFail(db, project, request->id,
-                          request->params.textDocument.uri.GetPath(), &file)) {
-        return;
-      }
-
-      WorkingFile* working_file = working_files->GetFileByFilename(
-          request->params.textDocument.uri.GetPath());
-      if (!working_file) {
-        LOG_S(WARNING) << "Unable to find working file "
-                       << request->params.textDocument.uri.GetPath();
-        return;
-      }
-      for (const IndexInclude& include : file->def->includes) {
-        std::optional<int> buffer_line = working_file->GetBufferPosFromIndexPos(
-            include.line, nullptr, false);
-        if (!buffer_line)
-          continue;
-
-        // Subtract 1 from line because querydb stores 1-based lines but
-        // vscode expects 0-based lines.
-        std::optional<lsRange> between_quotes = ExtractQuotedRange(
-            *buffer_line, working_file->buffer_lines[*buffer_line]);
-        if (!between_quotes)
-          continue;
-
-        lsDocumentLink link;
-        link.target = lsDocumentUri::FromPath(include.resolved_path);
-        link.range = *between_quotes;
-        out.result.push_back(link);
-      }
-    }
-
-    QueueManager::WriteStdout(kMethodType, out);
-  }
-};
-REGISTER_MESSAGE_HANDLER(Handler_TextDocumentDocumentLink);
-}  // namespace
diff --git a/src/project.cc b/src/project.cc
index 198d60f9..4ff67a2a 100644
--- a/src/project.cc
+++ b/src/project.cc
@@ -292,7 +292,7 @@ Project::Entry GetCompilationEntryFromCompileCommandEntry(
 std::vector<std::string> ReadCompilerArgumentsFromFile(
     const std::string& path) {
   std::vector<std::string> args;
-  for (std::string line : ReadLinesWithEnding(path)) {
+  for (std::string line : ReadFileLines(path)) {
     TrimInPlace(line);
     if (line.empty() || StartsWith(line, "#"))
       continue;
diff --git a/src/test.cc b/src/test.cc
index 4c8bde2a..016f0382 100644
--- a/src/test.cc
+++ b/src/test.cc
@@ -343,7 +343,7 @@ bool RunIndexTests(const std::string& filter_path, bool enable_update) {
       std::cout << "Running " << path << std::endl;
 
     // Parse expected output from the test, parse it into JSON document.
-    std::vector<std::string> lines_with_endings = ReadLinesWithEnding(path);
+    std::vector<std::string> lines_with_endings = ReadFileLines(path);
     TextReplacer text_replacer;
     std::vector<std::string> flags;
     std::unordered_map<std::string, std::string> all_expected_output;
diff --git a/src/utils.cc b/src/utils.cc
index 614e1c67..19af1c3f 100644
--- a/src/utils.cc
+++ b/src/utils.cc
@@ -1,10 +1,10 @@
 #include "utils.h"
 
+#include "filesystem.hh"
 #include "platform.h"
 
 #include <doctest/doctest.h>
 #include <siphash.h>
-#include <tinydir.h>
 #include <loguru/loguru.hpp>
 
 #include <algorithm>
@@ -18,10 +18,6 @@
 #include <string>
 #include <unordered_map>
 
-#if !defined(__APPLE__)
-#include <sparsepp/spp_memory.h>
-#endif
-
 // DEFAULT_RESOURCE_DIRECTORY is passed with quotes for non-MSVC compilers, ie,
 // foo vs "foo".
 #if defined(_MSC_VER)
@@ -31,22 +27,15 @@
 #define ENSURE_STRING_MACRO_ARGUMENT(x) x
 #endif
 
-// See http://stackoverflow.com/a/217605
-void TrimStartInPlace(std::string& s) {
+void TrimInPlace(std::string& s) {
   s.erase(s.begin(),
           std::find_if(s.begin(), s.end(),
                        std::not1(std::ptr_fun<int, int>(std::isspace))));
-}
-void TrimEndInPlace(std::string& s) {
   s.erase(std::find_if(s.rbegin(), s.rend(),
                        std::not1(std::ptr_fun<int, int>(std::isspace)))
               .base(),
           s.end());
 }
-void TrimInPlace(std::string& s) {
-  TrimStartInPlace(s);
-  TrimEndInPlace(s);
-}
 std::string Trim(std::string s) {
   TrimInPlace(s);
   return s;
@@ -138,32 +127,8 @@ std::string GetBaseName(const std::string& path) {
 }
 
 std::string StripFileType(const std::string& path) {
-  size_t last_period = path.find_last_of('.');
-  if (last_period != std::string::npos)
-    return path.substr(0, last_period);
-  return path;
-}
-
-// See http://stackoverflow.com/a/29752943
-std::string ReplaceAll(const std::string& source,
-                       const std::string& from,
-                       const std::string& to) {
-  std::string result;
-  result.reserve(source.length());  // avoids a few memory allocations
-
-  std::string::size_type last_pos = 0;
-  std::string::size_type find_pos;
-
-  while (std::string::npos != (find_pos = source.find(from, last_pos))) {
-    result.append(source, last_pos, find_pos - last_pos);
-    result += to;
-    last_pos = find_pos + from.length();
-  }
-
-  // Care for the rest after last occurrence
-  result += source.substr(last_pos);
-
-  return result;
+  fs::path p(path);
+  return p.parent_path() / p.stem();
 }
 
 std::vector<std::string> SplitString(const std::string& str,
@@ -198,51 +163,25 @@ static void GetFilesInFolderHelper(
     bool recursive,
     std::string output_prefix,
     const std::function<void(const std::string&)>& handler) {
-  std::queue<std::pair<std::string, std::string>> q;
-  q.push(make_pair(folder, output_prefix));
+  std::queue<std::pair<fs::path, fs::path>> q;
+  q.push(std::make_pair(fs::path(folder), fs::path(output_prefix)));
   while (!q.empty()) {
-    tinydir_dir dir;
-    if (tinydir_open(&dir, q.front().first.c_str()) == -1) {
-      LOG_S(WARNING) << "Unable to open directory " << folder;
-      goto bail;
-    }
-
-    while (dir.has_next) {
-      tinydir_file file;
-      if (tinydir_readfile(&dir, &file) == -1) {
-        LOG_S(WARNING) << "Unable to read file " << file.name
-                       << " when reading directory " << folder;
-        goto bail;
-      }
-
-      // Skip all dot files except .ccls.
-      //
-      // The nested ifs are intentional, branching order is subtle here.
-      //
-      // Note that in the future if we do support dot directories/files, we must
-      // always ignore the '.' and '..' directories otherwise this will loop
-      // infinitely.
-      if (file.name[0] != '.' || strcmp(file.name, ".ccls") == 0) {
-        if (file.is_dir) {
+    for (auto it = fs::directory_iterator(q.front().first); it != fs::directory_iterator(); ++it) {
+      auto path = it->path();
+      std::string filename = path.filename();
+      if (filename[0] != '.' || filename == ".ccls") {
+        fs::file_status status = it->symlink_status();
+        if (fs::is_regular_file(status))
+          handler(q.front().second / filename);
+        else if (fs::is_directory(status) || fs::is_symlink(status)) {
           if (recursive) {
-            std::string child_dir = q.front().second + file.name + "/";
-            if (!IsSymLink(file.path))
-              q.push(make_pair(file.path, child_dir));
+            std::string child_dir = q.front().second / filename;
+            if (fs::is_directory(status))
+              q.push(make_pair(path, child_dir));
           }
-        } else {
-          handler(q.front().second + file.name);
         }
       }
-
-      if (tinydir_next(&dir) == -1) {
-        LOG_S(WARNING) << "Unable to fetch next file when reading directory "
-                       << folder;
-        goto bail;
-      }
     }
-
-  bail:
-    tinydir_close(&dir);
     q.pop();
   }
 }
@@ -311,8 +250,7 @@ std::istream& SafeGetline(std::istream& is, std::string& t) {
 }
 
 bool FileExists(const std::string& filename) {
-  std::ifstream cache(filename);
-  return cache.is_open();
+  return fs::exists(filename);
 }
 
 std::optional<std::string> ReadContent(const std::string& filename) {
@@ -328,31 +266,20 @@ std::optional<std::string> ReadContent(const std::string& filename) {
   }
 }
 
-std::vector<std::string> ReadLinesWithEnding(std::string filename) {
+std::vector<std::string> ReadFileLines(std::string filename) {
   std::vector<std::string> result;
-
-  std::ifstream input(filename);
-  for (std::string line; SafeGetline(input, line);)
+  std::ifstream fin(filename);
+  for (std::string line; std::getline(fin, line);)
     result.push_back(line);
-
   return result;
 }
 
-std::vector<std::string> ToLines(const std::string& content,
-                                 bool trim_whitespace) {
+std::vector<std::string> ToLines(const std::string& content) {
   std::vector<std::string> result;
-
   std::istringstream lines(content);
-
   std::string line;
-  while (getline(lines, line)) {
-    if (trim_whitespace)
-      TrimInPlace(line);
-    else
-      RemoveLastCR(line);
+  while (getline(lines, line))
     result.push_back(line);
-  }
-
   return result;
 }
 
@@ -385,27 +312,6 @@ void WriteToFile(const std::string& filename, const std::string& content) {
   file << content;
 }
 
-float GetProcessMemoryUsedInMb() {
-#if defined(__APPLE__)
-  return 0.f;
-#else
-  const float kBytesToMb = 1000000;
-  uint64_t memory_after = spp::GetProcessMemoryUsed();
-  return memory_after / kBytesToMb;
-#endif
-}
-
-std::string FormatMicroseconds(long long microseconds) {
-  long long milliseconds = microseconds / 1000;
-  long long remaining = microseconds - milliseconds;
-
-  // Only show two digits after the dot.
-  while (remaining >= 100)
-    remaining /= 10;
-
-  return std::to_string(milliseconds) + "." + std::to_string(remaining) + "ms";
-}
-
 std::string GetDefaultResourceDirectory() {
   std::string result;
 
diff --git a/src/utils.h b/src/utils.h
index 860a8fa2..4eb42ca6 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -10,11 +10,6 @@
 #include <string>
 #include <vector>
 
-// Trim from start (in place)
-void TrimStartInPlace(std::string& s);
-// Trim from end (in place)
-void TrimEndInPlace(std::string& s);
-// Trim from both ends (in place)
 void TrimInPlace(std::string& s);
 std::string Trim(std::string s);
 
@@ -41,10 +36,6 @@ std::string GetBaseName(const std::string& path);
 // Returns |path| without the filetype, ie, "foo/bar.cc" => "foo/bar".
 std::string StripFileType(const std::string& path);
 
-std::string ReplaceAll(const std::string& source,
-                       const std::string& from,
-                       const std::string& to);
-
 std::vector<std::string> SplitString(const std::string& str,
                                      const std::string& delimiter);
 
@@ -95,9 +86,8 @@ std::string EscapeFileName(std::string path);
 // FIXME: Move ReadContent into ICacheManager?
 bool FileExists(const std::string& filename);
 std::optional<std::string> ReadContent(const std::string& filename);
-std::vector<std::string> ReadLinesWithEnding(std::string filename);
-std::vector<std::string> ToLines(const std::string& content,
-                                 bool trim_whitespace);
+std::vector<std::string> ReadFileLines(std::string filename);
+std::vector<std::string> ToLines(const std::string& content);
 
 struct TextReplacer {
   struct Replacement {
@@ -163,11 +153,4 @@ inline void hash_combine(std::size_t& seed, const T& v, Rest... rest) {
   };                                              \
   }
 
-float GetProcessMemoryUsedInMb();
-
-std::string FormatMicroseconds(long long microseconds);
-
 std::string GetDefaultResourceDirectory();
-
-// Makes sure all newlines in |output| are in \r\n format.
-std::string UpdateToRnNewlines(std::string output);
diff --git a/src/working_files.cc b/src/working_files.cc
index 52fcd516..478a6ff5 100644
--- a/src/working_files.cc
+++ b/src/working_files.cc
@@ -215,14 +215,14 @@ WorkingFile::WorkingFile(const std::string& filename,
 }
 
 void WorkingFile::SetIndexContent(const std::string& index_content) {
-  index_lines = ToLines(index_content, false /*trim_whitespace*/);
+  index_lines = ToLines(index_content);
 
   index_to_buffer.clear();
   buffer_to_index.clear();
 }
 
 void WorkingFile::OnBufferContentUpdated() {
-  buffer_lines = ToLines(buffer_content, false /*trim_whitespace*/);
+  buffer_lines = ToLines(buffer_content);
 
   index_to_buffer.clear();
   buffer_to_index.clear();