Add interface to Invariant

Author: sim642

src/cdomain/value/domains/invariant.ml

@@ -1,4 +1,4 @@
-(** Invariants for witnesses. *)
+
 
 open GoblintCil
 

src/cdomain/value/domains/invariant.mli

@@ -0,0 +1,17 @@
+(** Invariants for witnesses. *)
+
+include Lattice.S with type t = [ `Bot | `Lifted of GoblintCil.exp | `Top ]
+
+val none: t
+val of_exp: GoblintCil.exp -> t
+
+val (&&): t -> t -> t
+val (||): t -> t -> t
+
+
+type context = {
+  path: int option;
+  lvals: Lval.Set.t;
+}
+
+val default_context : context