diff --git a/.gitignore b/.gitignore
index 3225a63..81be867 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,5 @@
+build
+compile_commands.json
 CMakeCache.txt
 CMakeFiles/*
 cmake_install.cmake
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 135e02f..8a1cec4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -3,6 +3,7 @@
 set(CMAKE_BUILD_TYPE Release CACHE STRING "Build configuration (Debug, Release, RelWithDebInfo, MinSizeRel)")
 
 project(pdf2htmlEX)
+set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 cmake_minimum_required(VERSION 2.6.0 FATAL_ERROR)
 
 option(ENABLE_SVG "Enable SVG support, for generating SVG background images and converting Type 3 fonts" ON)
@@ -70,12 +71,12 @@ set(CMAKE_CXX_FLAGS_RELEASE "-O2 -DNDEBUG")
 
 # generic flags
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall")
-set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall")
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Woverloaded-virtual")
 
 # clang compiler need c++11 flag
-if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -stdlib=libc++")
-endif()
+#if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
+#  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -stdlib=libc++")
+#endif()
 
 # CYGWIN or GCC 4.5.x bug
 if(CYGWIN)
diff --git a/dobuild b/dobuild
index 5b55a1c..97e5ac1 100755
--- a/dobuild
+++ b/dobuild
@@ -1,4 +1,4 @@
 mkdir build
 cd build
 cmake ..
-make install
+make
diff --git a/dobuildClang b/dobuildClang
new file mode 100755
index 0000000..4a9914a
--- /dev/null
+++ b/dobuildClang
@@ -0,0 +1,4 @@
+mkdir build
+cd build
+CC=clang CXX=clang++ cmake ..
+make