[liveness] print type of unused var

Reviewed By: jeremydubreil

Differential Revision: D6539887

fbshipit-source-id: 9e819b0

infer/src/checkers/liveness.ml

@@ -146,9 +146,12 @@ let checker {Callbacks.tenv; summary; proc_desc} : Specs.summary =
       || Domain.mem (Var.of_pvar pvar) live_vars || Procdesc.is_captured_var proc_desc pvar
       || is_scope_guard typ || Procdesc.has_modify_in_block_attr proc_desc pvar )
   in
-  let log_report pvar loc =
+  let log_report pvar typ loc =
     let issue_id = IssueType.dead_store.unique_id in
-    let message = F.asprintf "The value written to %a is never used" (Pvar.pp Pp.text) pvar in
+    let message =
+      F.asprintf "The value written to %a (type %a) is never used" (Pvar.pp Pp.text) pvar
+        (Typ.pp_full Pp.text) typ
+    in
     let ltr = [Errlog.make_trace_element 0 loc "Write of unused value" []] in
     let exn = Exceptions.Checkers (issue_id, Localise.verbatim_desc message) in
     Reporting.log_error summary ~loc ~ltr exn
@@ -156,11 +159,11 @@ let checker {Callbacks.tenv; summary; proc_desc} : Specs.summary =
   let report_dead_store live_vars = function
     | Sil.Store (Lvar pvar, typ, rhs_exp, loc)
       when should_report pvar typ live_vars && not (is_sentinel_exp rhs_exp) ->
-        log_report pvar loc
+        log_report pvar typ loc
     | Sil.Call
         (None, Exp.Const Cfun (Typ.Procname.ObjC_Cpp _ as pname), (Exp.Lvar pvar, typ) :: _, loc, _)
       when Typ.Procname.is_constructor pname && should_report pvar typ live_vars ->
-        log_report pvar loc
+        log_report pvar typ loc
     | _ ->
         ()
   in