diff --git a/vpr7_x2p/vpr/CMakeLists.txt b/vpr7_x2p/vpr/CMakeLists.txt
index cb4a4190f..c614f2afc 100644
--- a/vpr7_x2p/vpr/CMakeLists.txt
+++ b/vpr7_x2p/vpr/CMakeLists.txt
@@ -20,11 +20,16 @@ if (ENABLE_VPR_GRAPHICS)
   if (NOT X11_FOUND)
     message(WARNING "Failed to find required X11 library (on debian/ubuntu try 'sudo apt-get install libx11-dev' to install)")
     #Disable
-  else ()
     set(ENABLE_VPR_GRAPHICS false)
   endif()
 endif()
-set(ENABLE_VPR_GRAPHICS false)
+
+if (NOT ENABLE_VPR_GRAPHICS)
+  # Add a flag to notify compiler not to consider graphic-related source codes   
+  set (DISABLE_GRAPHIC_FLAGS "-DNO_GRAPHICS")
+  set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${DISABLE_GRAPHIC_FLAGS}")
+  message(STATUS "Add flags to disable graphics in VPR compilation: ${DISABLE_GRAPHIC_FLAGS}")
+endif()
 
 # We need readline to compile 
 find_package(Readline REQUIRED)
@@ -51,10 +56,16 @@ target_include_directories(libvpr PUBLIC ${LIB_INCLUDE_DIRS})
 set_target_properties(libvpr PROPERTIES PREFIX "") #Avoid extra 'lib' prefix#Create the executable
 
 #Specify link-time dependancies
-target_link_libraries(libvpr
-                      libarchfpga
-                      X11
-                      readline)
+if (ENABLE_VPR_GRAPHICS)
+  target_link_libraries(libvpr
+                        libarchfpga
+                        X11
+                        readline)
+else () 
+  target_link_libraries(libvpr
+                        libarchfpga
+                        readline)
+endif()
 
 #Create the executables
 # regular vpr interface
diff --git a/vpr7_x2p/vpr/SRC/fpga_x2p/base/fpga_x2p_unique_routing.c b/vpr7_x2p/vpr/SRC/fpga_x2p/base/fpga_x2p_unique_routing.c
index 3e88b03a4..d8de7bfb8 100644
--- a/vpr7_x2p/vpr/SRC/fpga_x2p/base/fpga_x2p_unique_routing.c
+++ b/vpr7_x2p/vpr/SRC/fpga_x2p/base/fpga_x2p_unique_routing.c
@@ -1322,7 +1322,7 @@ DeviceRRGSB build_device_rr_gsb(boolean output_sb_xml, char* sb_xml_dir,
     for (size_t iseg = 0; iseg < LL_drive_rr_gsb.get_num_segments(); ++iseg) { 
       vpr_printf(TIO_MESSAGE_INFO, 
                  "For side %s, segment id %lu: Detect %d independent switch blocks from %d switch blocks.\n",
-                 side_manager.to_string(), LL_drive_rr_gsb.get_segment_id(iseg), 
+                 side_manager.c_str(), LL_drive_rr_gsb.get_segment_id(iseg), 
                  LL_drive_rr_gsb.get_num_sb_unique_submodule(side_manager.get_side(), iseg), 
                  (nx + 1) * (ny + 1) );
     }
diff --git a/vpr7_x2p/vpr/SRC/fpga_x2p/base/write_rr_blocks.cpp b/vpr7_x2p/vpr/SRC/fpga_x2p/base/write_rr_blocks.cpp
index 135b15ff1..fe525d6ab 100644
--- a/vpr7_x2p/vpr/SRC/fpga_x2p/base/write_rr_blocks.cpp
+++ b/vpr7_x2p/vpr/SRC/fpga_x2p/base/write_rr_blocks.cpp
@@ -1,9 +1,10 @@
 /* 
  * Output internal structure of classes defined in rr_blocks.h to XML format 
  */
+#include <cstdio>
+#include <cstring>
+#include <cassert>
 #include <fstream>
-#include <string.h>
-#include <assert.h>
 
 #include "rr_blocks.h"
 #include "rr_blocks_naming.h"