[swift] Fix translation of move_phi

Summary: When we translate phi nodes, in llair this is a move_phi, and, whilst in normal move, we do not deref variables, here it's necessary. It was needed in an example for optional types. Now we see another example, when adding deref is a problem, because the translation adds it again later leading to a typechecking error. Now we keep track of that the deref has been already added in the move, and we don't add it later. With this approach both examples work correctly.

Reviewed By: davidpichardie

Differential Revision:
D89551549

Privacy Context Container: L1208441

fbshipit-source-id: 7e0c80ef28f6d58c075467b28d89bbf99455fa5f

Author: dulmarod

infer/src/llvm/Llair2Textual.ml

@@ -260,8 +260,14 @@ let add_deref ~proc_state ?from_call exp loc =
   | Textual.Exp.Field _ ->
       add_load_instr
   | Textual.Exp.Var id -> (
-      let typ = IdentMap.find_opt id proc_state.ProcState.ids_move in
-      match typ with Some {typ= Textual.Typ.Ptr _} -> add_load_instr | _ -> ([], exp) )
+      let id_data = IdentMap.find_opt id proc_state.ProcState.ids_move in
+      match id_data with
+      | Some {no_deref_needed= true} ->
+          ([], exp)
+      | Some {typ= {typ= Textual.Typ.Ptr _}} ->
+          add_load_instr
+      | _ ->
+          ([], exp) )
   | _ ->
       ([], exp)
 
@@ -662,17 +668,31 @@ let remove_store_zero_in_class typ_exp1 exp2 =
       false
 
 
-let translate_move ~move_phi ~proc_state loc textual_instrs reg_exps =
+let translate_move ~proc_state ~move_phi loc textual_instrs reg_exps =
   let reg_exps = StdUtils.iarray_to_list reg_exps in
   let loc = to_textual_loc_instr ~proc_state loc in
   let instrs =
     List.fold
       ~f:(fun instrs (reg, exp) ->
         let id = Some (Var.reg_to_id ~proc_state reg |> fst) in
         let exp, exp_typ, exp_instrs = to_textual_exp loc ~proc_state exp in
+        let no_deref_needed =
+          match exp with
+          | Textual.Exp.Var var ->
+              Option.value_map
+                ~f:(fun id_data -> id_data.ProcState.no_deref_needed)
+                (IdentMap.find_opt var proc_state.ProcState.ids_move)
+                ~default:false
+          | _ when move_phi ->
+              true
+          | _ ->
+              false
+        in
         ( match (id, exp_typ) with
         | Some id, Some exp_typ ->
-            ProcState.update_ids_move ~proc_state id (Textual.Typ.mk_without_attributes exp_typ)
+            ProcState.update_ids_move ~proc_state id
+              (Textual.Typ.mk_without_attributes exp_typ)
+              ~no_deref_needed
         | _ ->
             () ) ;
         let deref_instrs, exp = if move_phi then add_deref ~proc_state exp loc else ([], exp) in
@@ -816,9 +836,9 @@ let cmnd_to_instrs ~(proc_state : ProcState.t) block =
         let call_textual_instrs = to_textual_builtin ~proc_state reg name args loc in
         List.append call_textual_instrs textual_instrs
     | Move {reg_exps: (Reg.t * Exp.t) NS.iarray; loc} ->
-        translate_move ~move_phi:false ~proc_state loc textual_instrs reg_exps
+        translate_move ~proc_state ~move_phi:false loc textual_instrs reg_exps
     | MovePhi {reg_exps: (Reg.t * Exp.t) NS.iarray; loc} ->
-        translate_move ~move_phi:true ~proc_state loc textual_instrs reg_exps
+        translate_move ~proc_state ~move_phi:true loc textual_instrs reg_exps
     | AtomicRMW {reg; ptr; exp; loc} ->
         let loc = to_textual_loc ~proc_state loc in
         let call_textual_instrs =

infer/src/llvm/Llair2TextualState.ml

@@ -98,14 +98,20 @@ module ModuleState = struct
 end
 
 module ProcState = struct
+  type id_data = {typ: Textual.Typ.annotated; no_deref_needed: bool}
+
+  let pp_data fmt {typ; no_deref_needed} =
+    F.fprintf fmt "typ:%a, no_deref_needed: %b" Textual.Typ.pp_annotated typ no_deref_needed
+
+
   type t =
     { qualified_name: Textual.QualifiedProcName.t
     ; sourcefile: SourceFile.t
     ; loc: Textual.Location.t
     ; mutable locals: Textual.Typ.annotated VarMap.t
     ; mutable formals: (Textual.Typ.annotated * Textual.VarName.t option) VarMap.t
     ; mutable local_map: Textual.Typ.t Textual.VarName.Hashtbl.t
-    ; mutable ids_move: Textual.Typ.annotated IdentMap.t
+    ; mutable ids_move: id_data IdentMap.t
     ; mutable ids_types: Textual.Typ.annotated IdentMap.t
     ; mutable id_offset: (Textual.Ident.t * int) option
     ; mutable get_element_ptr_offset: (Textual.VarName.t * int) option
@@ -159,6 +165,11 @@ module ProcState = struct
         (Pp.comma_seq (Pp.pair ~fst:Textual.Ident.pp ~snd:Textual.Typ.pp_annotated))
         (IdentMap.bindings current_ids)
     in
+    let pp_ids_data fmt current_ids =
+      F.fprintf fmt "%a"
+        (Pp.comma_seq (Pp.pair ~fst:Textual.Ident.pp ~snd:pp_data))
+        (IdentMap.bindings current_ids)
+    in
     let pp_vars fmt vars =
       F.fprintf fmt "%a"
         (Pp.comma_seq (Pp.pair ~fst:Textual.VarName.pp ~snd:Textual.Typ.pp_annotated))
@@ -188,7 +199,7 @@ module ProcState = struct
        @[get_element_ptr_offset: %a@]@;\
        ]@]"
       Textual.QualifiedProcName.pp proc_state.qualified_name Textual.Location.pp proc_state.loc
-      pp_vars proc_state.locals pp_formals proc_state.formals pp_ids proc_state.ids_move pp_ids
+      pp_vars proc_state.locals pp_formals proc_state.formals pp_ids_data proc_state.ids_move pp_ids
       proc_state.ids_types
       (Pp.option (Pp.pair ~fst:Textual.Ident.pp ~snd:Int.pp))
       proc_state.id_offset
@@ -201,8 +212,8 @@ module ProcState = struct
     proc_state.locals <- VarMap.add varname typ proc_state.locals
 
 
-  let update_ids_move ~proc_state id typ =
-    proc_state.ids_move <- IdentMap.add id typ proc_state.ids_move
+  let update_ids_move ~proc_state id typ ~no_deref_needed =
+    proc_state.ids_move <- IdentMap.add id {typ; no_deref_needed} proc_state.ids_move
 
 
   (* debug_name = var1,

infer/src/llvm/Llair2TextualState.mli

@@ -81,14 +81,16 @@ module ModuleState : sig
 end
 
 module ProcState : sig
+  type id_data = {typ: Textual.Typ.annotated; no_deref_needed: bool}
+
   type t = private
     { qualified_name: Textual.QualifiedProcName.t
     ; sourcefile: SourceFile.t
     ; loc: Textual.Location.t
     ; mutable locals: Textual.Typ.annotated VarMap.t
     ; mutable formals: (Textual.Typ.annotated * Textual.VarName.t option) VarMap.t
     ; mutable local_map: Textual.Typ.t Textual.VarName.Hashtbl.t
-    ; mutable ids_move: Textual.Typ.annotated IdentMap.t
+    ; mutable ids_move: id_data IdentMap.t
     ; mutable ids_types: Textual.Typ.annotated IdentMap.t
     ; mutable id_offset: (Textual.Ident.t * int) option
     ; mutable get_element_ptr_offset: (Textual.VarName.t * int) option
@@ -111,7 +113,8 @@ module ProcState : sig
 
   val update_locals : proc_state:t -> VarMap.key -> Textual.Typ.annotated -> unit
 
-  val update_ids_move : proc_state:t -> IdentMap.key -> Textual.Typ.annotated -> unit
+  val update_ids_move :
+    proc_state:t -> IdentMap.key -> Textual.Typ.annotated -> no_deref_needed:bool -> unit
 
   val update_ids_types : proc_state:t -> IdentMap.key -> Textual.Typ.annotated -> unit
 

infer/tests/codetoanalyze/swift/frontend/retain_cycle.swift.sil

@@ -493,8 +493,7 @@ define .plain_name = "rawValue.get" $s5Hello9TransportC15ConnectionStateO8rawVal
   #13: @[246:0]
       n14 = $builtins.llvm_init_tuple() @[246:0]
       store n14.__infer_tuple_class<int,*__infer_swift_type<ptr_elt>>.__infer_tuple_field_0 <- n8 @[247:0]
-      n16 = load n11 @[247:0]
-      store n14.__infer_tuple_class<int,*__infer_swift_type<ptr_elt>>.__infer_tuple_field_1 <- n16 @[247:0]
+      store n14.__infer_tuple_class<int,*__infer_swift_type<ptr_elt>>.__infer_tuple_field_1 <- n11 @[247:0]
       ret n14 @[247:0]
 
   #5: @[242:0]