[access paths] don't compare types of bases

Reviewed By: jberdine

Differential Revision: D4832309

fbshipit-source-id: 9f39615

infer/src/IR/Typ.re

@@ -251,15 +251,6 @@ let module Map = Caml.Map.Make T;
 let module Tbl = Hashtbl.Make T;
 
 
-/** type comparison that treats T* [] and T** as the same type. Needed for C/C++ */
-let array_sensitive_compare t1 t2 =>
-  switch (t1, t2) {
-  | (Tptr (Tptr ptr_typ _) _, Tarray (Tptr array_typ _) _) => compare ptr_typ array_typ
-  | (Tarray (Tptr array_typ _) _, Tptr (Tptr ptr_typ _) _) => compare array_typ ptr_typ
-  | _ => compare t1 t2
-  };
-
-
 /** Pretty print a type with all the details, using the C syntax. */
 let rec pp_full pe f =>
   fun

infer/src/IR/Typ.rei

@@ -171,10 +171,6 @@ let module Map: Caml.Map.S with type key = t;
 let module Tbl: Caml.Hashtbl.S with type key = t;
 
 
-/** type comparison that treats T* [] and T** as the same type. Needed for C/C++ */
-let array_sensitive_compare: t => t => int;
-
-
 /** Pretty print a type with all the details. */
 let pp_full: Pp.env => F.formatter => t => unit;
 

infer/src/checkers/ThreadSafetyDomain.ml

@@ -11,7 +11,7 @@ open! IStd
 
 module F = Format
 
-module AccessPathSetDomain = AbstractDomain.InvertedSet(AccessPath.UntypedRawSet)
+module AccessPathSetDomain = AbstractDomain.InvertedSet(AccessPath.RawSet)
 
 module Access = struct
   type kind =
@@ -110,7 +110,7 @@ end
 module AttributeSetDomain = AbstractDomain.InvertedSet (Attribute.Set)
 
 module AttributeMapDomain = struct
-  include AbstractDomain.InvertedMap (AccessPath.UntypedRawMap) (AttributeSetDomain)
+  include AbstractDomain.InvertedMap (AccessPath.RawMap) (AttributeSetDomain)
 
   let has_attribute access_path attribute t =
     try
@@ -201,7 +201,7 @@ let empty =
   let locks = false in
   let accesses = AccessDomain.empty in
   let id_map = IdAccessPathMapDomain.empty in
-  let attribute_map = AccessPath.UntypedRawMap.empty in
+  let attribute_map = AccessPath.RawMap.empty in
   { threads; locks; accesses; id_map; attribute_map; }
 
 let (<=) ~lhs ~rhs =

infer/src/checkers/ThreadSafetyDomain.mli

@@ -11,7 +11,7 @@ open! IStd
 
 module F = Format
 
-module AccessPathSetDomain : module type of AbstractDomain.InvertedSet (AccessPath.UntypedRawSet)
+module AccessPathSetDomain : module type of AbstractDomain.InvertedSet (AccessPath.RawSet)
 
 module Access : sig
   type kind =
@@ -74,7 +74,7 @@ end
 module AttributeSetDomain : module type of AbstractDomain.InvertedSet (Attribute.Set)
 
 module AttributeMapDomain : sig
-  include module type of AbstractDomain.InvertedMap (AccessPath.UntypedRawMap) (AttributeSetDomain)
+  include module type of AbstractDomain.InvertedMap (AccessPath.RawMap) (AttributeSetDomain)
 
   val has_attribute : AccessPath.Raw.t -> Attribute.t -> astate -> bool
 

infer/src/checkers/accessPath.ml

@@ -11,19 +11,16 @@ open! IStd
 
 module F = Format
 
-type _array_sensitive_typ = Typ.t
+type _typ = Typ.t
 
-let compare__array_sensitive_typ = Typ.array_sensitive_compare
+let compare__typ _ _ = 0
 
-type base = Var.t * _array_sensitive_typ [@@deriving compare]
+(* ignore types while comparing bases. we can't trust the types from all of our frontends to be
+   consistent, and the variable names should already be enough to distinguish the bases. *)
+type base = Var.t * _typ [@@deriving compare]
 
 let equal_base = [%compare.equal : base]
 
-let compare_base_untyped (base_var1, _) (base_var2, _) =
-  if phys_equal base_var1 base_var2
-  then 0
-  else Var.compare base_var1 base_var2
-
 type access =
   | ArrayAccess of Typ.t
   | FieldAccess of Fieldname.t
@@ -31,7 +28,6 @@ type access =
 
 let equal_access = [%compare.equal : access]
 
-
 let equal_access_list l1 l2 =  Int.equal (List.compare compare_access l1 l2) 0
 
 let pp_base fmt (pvar, _) =
@@ -74,22 +70,6 @@ module Raw = struct
     | base, accesses ->  F.fprintf fmt "%a.%a" pp_base base pp_access_list accesses
 end
 
-module UntypedRaw = struct
-  type t = Raw.t
-
-  (* untyped comparison *)
-  let compare ((base1, accesses1) as raw1) ((base2, accesses2) as raw2) =
-    if phys_equal raw1 raw2
-    then
-      0
-    else
-      let n = compare_base_untyped base1 base2 in
-      if n <> 0 then n
-      else List.compare compare_access accesses1 accesses2
-
-  let pp = Raw.pp
-end
-
 type t =
   | Abstracted of Raw.t
   | Exact of Raw.t
@@ -207,7 +187,3 @@ module AccessMap = PrettyPrintable.MakePPMap(struct
 module RawSet = PrettyPrintable.MakePPSet(Raw)
 
 module RawMap = PrettyPrintable.MakePPMap(Raw)
-
-module UntypedRawSet = PrettyPrintable.MakePPSet(UntypedRaw)
-
-module UntypedRawMap = PrettyPrintable.MakePPMap(UntypedRaw)

infer/src/checkers/accessPath.mli

@@ -102,7 +102,3 @@ module AccessMap : PrettyPrintable.PPMap with type key = access
 module RawSet : PrettyPrintable.PPSet with type elt = Raw.t
 
 module RawMap : PrettyPrintable.PPMap with type key = Raw.t
-
-module UntypedRawSet : PrettyPrintable.PPSet with type elt = Raw.t
-
-module UntypedRawMap : PrettyPrintable.PPMap with type key = Raw.t

infer/tests/codetoanalyze/java/threadsafety/Containers.java

@@ -187,4 +187,17 @@ class Containers {
     obj.f = new Object(); // should flag
   }
 
+  private static List addOrCreateList(List list) {
+    if (list == null) {
+      list = new ArrayList<>();
+    }
+    list.add(new Object());
+    return list;
+  }
+
+  public void addToNullListOk() {
+    List list = null;
+    addOrCreateList(list);
+  }
+
 }