title: How to use functions in Value.Eval_expr, Value.Eval_op etc modules of Frama-c Value plugin
body: <p>I am trying to create a frama-c plugin. This plugin depends upon Frama-c Value plugin. I want to obtain and print value set of all the lvalue(s) in a C source code. In order to do that I want to use functions available in Value.Eval_exprs, Value.Eval_op etc. like <code>Eval_exprs.lval_to_precise_loc</code>. </p>
  
  <p>Unfortunately I am unable to figure out a way to use these function in my plugin. I tried to follow steps mentioned in section 4.10.1 (Registration through a .mli file) of Frama-c Plugin Development Guide and added <code>PLUGIN_DEPENDENCIES:=Value</code> in my Makefile but I noticed that <code>Value.mli</code> file is empty and no function is exposed through this file. After that I looked at <code>db.ml</code> file in <code>kernel</code> directory and couldn't find any module that can be used to access all the functions available in Eval_exprs, Eval_op etc. </p>
  
  <p>Is there any way to access these functions of Value plugin from other plugin?</p>