[pulse] better pretty-printing of stacks

Summary: Instead of `x -> 4` print the more accurate `&x=4`.

Reviewed By: da319

Differential Revision: D13518669

fbshipit-source-id: 6ca28d0e1

infer/src/checkers/PulseDomain.ml

@@ -224,9 +224,20 @@ end
     functor followed by normalization wrt the unification found between abstract locations so it's
     convenient to define stacks as elements of this domain. *)
 module Stack = struct
-  include AbstractDomain.Map
-            (Var)
-            (struct
+  module VarAddress = struct
+    include Var
+
+    let pp f var =
+      let pp_ampersand f = function
+        | ProgramVar _ ->
+            F.pp_print_string f "&"
+        | LogicalVar _ ->
+            ()
+      in
+      F.fprintf f "%a%a" pp_ampersand var Var.pp var
+  end
+
+  module ValueDomain = struct
     type t = AbstractAddress.t
 
     let ( <= ) ~lhs ~rhs = AbstractAddress.equal lhs rhs
@@ -236,7 +247,16 @@ module Stack = struct
     let widen ~prev ~next ~num_iters:_ = join prev next
 
     let pp = AbstractAddress.pp
-            end)
+  end
+
+  include AbstractDomain.Map (VarAddress) (ValueDomain)
+
+  let pp fmt m =
+    let pp_item fmt (var_address, v) =
+      F.fprintf fmt "%a=%a" VarAddress.pp var_address ValueDomain.pp v
+    in
+    PrettyPrintable.pp_collection ~pp_item fmt (bindings m)
+
 
   let compare = compare AbstractAddress.compare
 end