Node.pname_opt doesn't have to be an option

Summary:
Now that we got rid of dummy nodes used non-dummily (biabduction state, reporting), `pname` don't need to be an option anymore.
Let's save a boxing on all nodes.

Reviewed By: jeremydubreil

Differential Revision: D9654152

fbshipit-source-id: 83b00f239

infer/src/IR/Procdesc.ml

@@ -93,7 +93,7 @@ module Node = struct
     ; kind: nodekind  (** kind of node *)
     ; loc: Location.t  (** location in the source code *)
     ; mutable preds: t list  (** predecessor nodes in the cfg *)
-    ; pname_opt: Typ.Procname.t option  (** name of the procedure the node belongs to *)
+    ; pname: Typ.Procname.t  (** name of the procedure the node belongs to *)
     ; mutable succs: t list  (** successor nodes in the cfg *) }
 
   let exn_handler_kind = Stmt_node ExceptionHandler
@@ -102,13 +102,13 @@ module Node = struct
 
   let throw_kind = Stmt_node Throw
 
-  let dummy pname_opt =
+  let dummy pname =
     { id= 0
     ; dist_exit= None
     ; instrs= Instrs.empty
     ; kind= Skip_node "dummy"
     ; loc= Location.dummy
-    ; pname_opt
+    ; pname
     ; succs= []
     ; preds= []
     ; exn= [] }
@@ -142,14 +142,7 @@ module Node = struct
   let get_exn node = node.exn
 
   (** Get the name of the procedure the node belongs to *)
-  let get_proc_name node =
-    match node.pname_opt with
-    | None ->
-        L.internal_error "get_proc_name: at node %d@\n" node.id ;
-        assert false
-    | Some pname ->
-        pname
-
+  let get_proc_name node = node.pname
 
   (** Get the predecessors of the node *)
   let get_preds node = node.preds
@@ -408,9 +401,9 @@ type t =
   ; mutable loop_heads: NodeSet.t option  (** loop head nodes of this procedure *) }
 
 let from_proc_attributes attributes =
-  let pname_opt = Some attributes.ProcAttributes.proc_name in
-  let start_node = Node.dummy pname_opt in
-  let exit_node = Node.dummy pname_opt in
+  let pname = attributes.ProcAttributes.proc_name in
+  let start_node = Node.dummy pname in
+  let exit_node = Node.dummy pname in
   {attributes; nodes= []; nodes_num= 0; start_node; exit_node; loop_heads= None}
 
 
@@ -549,7 +542,7 @@ let create_node_internal pdesc loc kind instrs =
     ; kind
     ; loc
     ; preds= []
-    ; pname_opt= Some pdesc.attributes.proc_name
+    ; pname= pdesc.attributes.proc_name
     ; succs= []
     ; exn= [] }
   in

infer/src/IR/Procdesc.mli

@@ -94,7 +94,7 @@ module Node : sig
   val d_instrs : sub_instrs:bool -> Sil.instr option -> t -> unit
   (** Dump extended instructions for the node *)
 
-  val dummy : Typ.Procname.t option -> t
+  val dummy : Typ.Procname.t -> t
   (** Create a dummy node *)
 
   val equal : t -> t -> bool

infer/src/backend/preanal.ml

@@ -65,7 +65,7 @@ module NullifyTransferFunctions = struct
         astate
 
 
-  let cache_node = ref (Procdesc.Node.dummy None)
+  let cache_node = ref (Procdesc.Node.dummy Typ.Procname.Linters_dummy_method)
 
   let cache_instr = ref Sil.skip_instr
 

infer/src/biabduction/Paths.ml

@@ -371,20 +371,19 @@ end = struct
           ()
     in
     iter_shortest_sequence (fun _ p _ _ -> add_node (curr_node p)) None path ;
-    let max_rep_node = ref (Procdesc.Node.dummy None) in
-    let max_rep_num = ref 0 in
-    Procdesc.NodeMap.iter
-      (fun node num ->
-        if num > !max_rep_num then (
-          max_rep_node := node ;
-          max_rep_num := num ) )
-      !map ;
-    (!max_rep_node, !max_rep_num)
+    let max_rep_opt =
+      Procdesc.NodeMap.fold
+        (fun node num max_rep_opt ->
+          if num > Option.value_map max_rep_opt ~default:0 ~f:fst then Some (num, node)
+          else max_rep_opt )
+        !map None
+    in
+    Option.value_exn max_rep_opt
 
 
   let stats_string path =
     Invariant.compute_stats true (fun _ -> true) path ;
-    let node, repetitions = repetitions path in
+    let repetitions, node = repetitions path in
     let str =
       "linear paths: "
       ^ string_of_float (Invariant.get_stats path).linear_num