diff --git a/.vim/plugin/cdg.py b/.vim/plugin/cdg.py
new file mode 100755
index 0000000..84ff973
--- /dev/null
+++ b/.vim/plugin/cdg.py
@@ -0,0 +1,116 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+import json
+import sys
+import re
+
+
+'''A simple compilation database generator, or cdg in short.
+
+It works by parsing the output of the GNU make command.'''
+
+file_name_regex = re.compile(r"[\w./+\-]+\.(s|cc?|cpp|cxx)\b",
+                             re.IGNORECASE)
+enter_dir_regex = re.compile(r"^\s*make(?:\[\d+\])?: Entering directory [`\'\"](?P<dir>.*)[`\'\"]\s*$",
+                             re.MULTILINE)
+leave_dir_regex = re.compile(r"^\s*make(?:\[\d+\])?: Leaving directory .*$",
+                             re.MULTILINE)
+compilers_regex = re.compile(r'\b(g?cc|[gc]\+\+|clang\+?\+?|icecc|s?ccache)\s')
+
+
+def parse(make_output):
+    '''Parse the make output into a list of objects.
+
+Per https://clang.llvm.org/docs/JSONCompilationDatabase.html
+'''
+    result = []
+    pwd = ""
+    path_stack = []
+    for line in make_output.replace('\r', '').split('\n'):
+        line = line.strip()
+
+        enter_dir_match = enter_dir_regex.match(line)
+        if enter_dir_match:
+            pwd = enter_dir_match.group('dir')
+            path_stack.append(pwd)
+            # logger.debug("stack after append: {}".format(path_stack))
+            continue
+        elif leave_dir_regex.match(line):
+            # logger.debug("stack before pop: {}".format(path_stack))
+            path_stack.pop()
+            if path_stack:
+                pwd = path_stack[-1]
+            continue
+
+        match = compilers_regex.search(line)
+        if not match:
+            continue
+
+        # look backward and discard anything before delimiters
+        i = match.start()
+        while i > 0:
+            j = i - 1
+            if line[j] in (' ', '\t', '\n', ';', '&'):
+                break
+            i -= 1
+        line = line[i:]
+
+        file_match = file_name_regex.search(line)
+        # logger.debug(line, file_match)
+        if not file_match:
+            continue
+
+        # To workaround that there is no "entering directory..."
+        if not pwd:
+            pwd = "/path/to/your/project/"
+            path_stack.append(pwd)
+
+        # Special handling for projects like Redis,
+        # which has output like "printf xxx; cc xxx"
+        command = line
+        ri = command.rfind(';')
+        if -1 != ri:
+            command = command[:ri]
+        ri = command.rfind('&&')
+        if -1 != ri:
+            command = command[:ri]
+
+        result.append({
+            "directory": pwd.strip(),
+            "file": file_match.group(0).strip(),
+            "command": command.strip(),
+        })
+
+    return result
+
+
+def usage():
+    print('''Usage: {} [compilation-db-file]
+
+[compilation-db-file] is optional, which is `compile_commands.json` by default.
+Specify it if you want to write to another file, and specify `-` for stdout.
+
+This CLI program takes GNU make output from stdin from a pipe,
+parse it, and write the json string to a file.
+'''.format(sys.argv[0]))
+    sys.exit(1)
+
+
+def main():
+    make_output = sys.stdin.read().strip()
+    if not make_output:
+        usage()
+
+    db = json.dumps(parse(make_output),
+                    indent=2) + '\n'
+    file_name = 'compile_commands.json' if len(sys.argv) == 1 else sys.argv[1]
+    if '-' != file_name:
+        with open(file_name, "w") as f:
+            f.write(db)
+    else:
+        sys.stdout.write(db)
+
+
+if __name__ == '__main__':
+    main()
diff --git a/.vim/plugin/cscope_plus.vim b/.vim/plugin/cscope_plus.vim
index 3ce3c7b..2e7773d 100644
--- a/.vim/plugin/cscope_plus.vim
+++ b/.vim/plugin/cscope_plus.vim
@@ -116,12 +116,15 @@ func! MenuCB(id, result)
 		execute "!compiledb -n" g:build_cmd
 	elseif a:result == 8 "https://github.com/rizsotto/scan-build
 		execute "!analyze-build"
+	elseif a:result == 9
+		execute "!make clean > /dev/null && make -nw | python ~/.vim/plugin/cdg.py "
+	elseif a:result == 10
+		echo "Add -DCMAKE_EXPORT_COMPILE_COMMANDS=ON to cmake. On modify build option with ccmake"
 	endif
-	"Add -DCMAKE_EXPORT_COMPILE_COMMANDS=ON with cmake build
 endfunc
 
 command! ShowMenuCodeDb
-			\ :call popup_menu(['tag/csope', 'tag/cscope Kernel', 'Autotags update', 'Autotags add dependancy','simple compile_commands', 'bear', "compiledb", "analyse build"], #{
+			\ :call popup_menu(['tag/csope', 'tag/cscope Kernel', 'Autotags update', 'Autotags add dependancy','simple compile_commands', 'bear', "compiledb", "analyse build", "rebuild with make parsing", "cmake option"], #{
 			\ title: "Code database for ".g:build_cmd,
 			\ callback: 'MenuCB', highlight: 'Question', padding: [1,1,0,1]} )