[cost] Find method of interface or abstract class

Summary:
To find a method in non-abstract sub-classes, this diff applies the
same heuristics of inferbo.

* If the class is an interface: Find its unique sub-class and apply the heuristics recursively.

* If the class is an abstract class: Find/use its own summary if possible. If not found, find
  one (arbitrary but deterministic) summary from its sub-classes.

* Otherwise: Find its own summary.

Reviewed By: ezgicicek

Differential Revision: D20647101

fbshipit-source-id: 2f8f3ff81

infer/src/IR/Struct.ml

@@ -12,14 +12,18 @@ type field = Fieldname.t * Typ.t * Annot.Item.t [@@deriving compare]
 
 type fields = field list
 
+type java_class_kind = Interface | AbstractClass | NormalClass
+
 (** Type for a structured value. *)
 type t =
   { fields: fields  (** non-static fields *)
   ; statics: fields  (** static fields *)
   ; supers: Typ.Name.t list  (** superclasses *)
+  ; subs: Typ.Name.Set.t  (** subclasses, initialized after merging type environments *)
   ; methods: Procname.t list  (** methods defined *)
   ; exported_objc_methods: Procname.t list  (** methods in ObjC interface, subset of [methods] *)
   ; annots: Annot.Item.t  (** annotations *)
+  ; java_class_kind: java_class_kind option  (** class kind in Java *)
   ; dummy: bool  (** dummy struct for class including static method *) }
 
 type lookup = Typ.Name.t -> t option
@@ -56,20 +60,23 @@ let pp pe name f {fields; supers; methods; exported_objc_methods; annots} =
 
 
 let internal_mk_struct ?default ?fields ?statics ?methods ?exported_objc_methods ?supers ?annots
-    ?dummy () =
+    ?java_class_kind ?dummy () =
   let default_ =
     { fields= []
     ; statics= []
     ; methods= []
     ; exported_objc_methods= []
     ; supers= []
+    ; subs= Typ.Name.Set.empty
     ; annots= Annot.Item.empty
+    ; java_class_kind= None
     ; dummy= false }
   in
   let mk_struct_ ?(default = default_) ?(fields = default.fields) ?(statics = default.statics)
       ?(methods = default.methods) ?(exported_objc_methods = default.exported_objc_methods)
-      ?(supers = default.supers) ?(annots = default.annots) ?(dummy = default.dummy) () =
+      ?(supers = default.supers) ?(subs = default.subs) ?(annots = default.annots)
-    {fields; statics; methods; exported_objc_methods; supers; annots; dummy}
+      ?(dummy = default.dummy) () =
+    {fields; statics; methods; exported_objc_methods; supers; subs; annots; java_class_kind; dummy}
   in
   mk_struct_ ?default ?fields ?statics ?methods ?exported_objc_methods ?supers ?annots ?dummy ()
 
@@ -142,3 +149,5 @@ let get_field_type_and_annotation ~lookup field_name_to_lookup typ =
 
 
 let is_dummy {dummy} = dummy
+
+let add_sub sub x = {x with subs= Typ.Name.Set.add sub x.subs}

infer/src/IR/Struct.mli

@@ -13,14 +13,18 @@ type field = Fieldname.t * Typ.t * Annot.Item.t [@@deriving compare]
 
 type fields = field list
 
+type java_class_kind = Interface | AbstractClass | NormalClass
+
 (** Type for a structured value. *)
 type t = private
   { fields: fields  (** non-static fields *)
   ; statics: fields  (** static fields *)
   ; supers: Typ.Name.t list  (** supers *)
+  ; subs: Typ.Name.Set.t  (** subclasses, initialized after merging type environments *)
   ; methods: Procname.t list  (** methods defined *)
   ; exported_objc_methods: Procname.t list  (** methods in ObjC interface, subset of [methods] *)
   ; annots: Annot.Item.t  (** annotations *)
+  ; java_class_kind: java_class_kind option  (** class kind in Java *)
   ; dummy: bool  (** dummy struct for class including static method *) }
 
 type lookup = Typ.Name.t -> t option
@@ -38,6 +42,7 @@ val internal_mk_struct :
   -> ?exported_objc_methods:Procname.t list
   -> ?supers:Typ.Name.t list
   -> ?annots:Annot.Item.t
+  -> ?java_class_kind:java_class_kind
   -> ?dummy:bool
   -> unit
   -> t
@@ -60,3 +65,6 @@ val get_field_type_and_annotation :
 (** Return the type of the field [fn] and its annotation, None if [typ] has no field named [fn] *)
 
 val is_dummy : t -> bool
+
+val add_sub : Typ.Name.t -> t -> t
+(** Add a subclass to the struct type *)

infer/src/IR/Tenv.ml

@@ -29,11 +29,11 @@ let pp fmt (tenv : t) =
 let create () = TypenameHash.create 1000
 
 (** Construct a struct type in a type environment *)
-let mk_struct tenv ?default ?fields ?statics ?methods ?exported_objc_methods ?supers ?annots ?dummy
+let mk_struct tenv ?default ?fields ?statics ?methods ?exported_objc_methods ?supers ?annots
-    name =
+    ?java_class_kind ?dummy name =
   let struct_typ =
     Struct.internal_mk_struct ?default ?fields ?statics ?methods ?exported_objc_methods ?supers
-      ?annots ?dummy ()
+      ?annots ?java_class_kind ?dummy ()
   in
   TypenameHash.replace tenv name struct_typ ;
   struct_typ
@@ -169,6 +169,19 @@ let store_to_filename tenv tenv_filename =
   if Config.debug_mode then store_debug_file tenv tenv_filename
 
 
+let init_inheritances tenv =
+  let sub_to_supers =
+    TypenameHash.fold (fun sub {Struct.supers} acc -> (sub, supers) :: acc) tenv []
+  in
+  List.iter sub_to_supers ~f:(fun (sub, supers) ->
+      List.iter supers ~f:(fun super ->
+          (* Ignore the super class of java.lang.Object since its sub-classes are too many, which
+             harms the analysis precision. *)
+          if not (Typ.Name.equal super Typ.Name.Java.java_lang_object) then
+            Option.iter (lookup tenv super) ~f:(fun super_struct ->
+                Struct.add_sub sub super_struct |> TypenameHash.replace tenv super ) ) )
+
+
 let store_global tenv =
   (* update in-memory global tenv for later uses by this process, e.g. in single-core mode the
      frontend and backend run in the same process *)
@@ -177,5 +190,52 @@ let store_global tenv =
   let tenv = TypenameHashNormalizer.normalize tenv in
   L.debug Capture Quiet "Tenv.store: canonicalized tenv has size %d bytes.@."
     (Obj.(reachable_words (repr tenv)) * (Sys.word_size / 8)) ;
+  init_inheritances tenv ;
   global_tenv := Some tenv ;
   store_to_filename tenv global_tenv_path
+
+
+let get_summary_formals tenv ~get_summary ~get_formals =
+  let get pname =
+    match (get_summary pname, get_formals pname) with
+    | Some summary, Some formals ->
+        `Found (summary, formals)
+    | _, _ ->
+        `NotFound
+  in
+  let found_from_subclass pname = function
+    | `Found (summary, formals) ->
+        `FoundFromSubclass (pname, summary, formals)
+    | v ->
+        v
+  in
+  let rec get_summary_formals_aux pname =
+    match get pname with
+    | `Found _ as v ->
+        v
+    | `NotFound -> (
+      match Procname.get_class_type_name pname with
+      | None ->
+          `NotFound
+      | Some class_name when String.is_prefix (Typ.Name.name class_name) ~prefix:"java." ->
+          (* Note: We do not search sub-classes of `java.` because the super-classes are too
+             general.  Selecting one arbitrary sub-class of them does not help in making preciser
+             analysis results. *)
+          `NotFound
+      | Some class_name -> (
+        match lookup tenv class_name with
+        | Some {Struct.java_class_kind= Some Interface; subs}
+          when Int.equal (Typ.Name.Set.cardinal subs) 1 ->
+            let unique_sub = Typ.Name.Set.choose subs in
+            Logging.d_printfln_escaped "Found a unique sub-class %a" Typ.Name.pp unique_sub ;
+            let sub_pname = Procname.replace_class pname unique_sub in
+            get_summary_formals_aux sub_pname |> found_from_subclass sub_pname
+        | Some {Struct.java_class_kind= Some AbstractClass; subs} ->
+            Option.value_map (Typ.Name.Set.min_elt_opt subs) ~default:`NotFound ~f:(fun sub ->
+                Logging.d_printfln_escaped "Found an arbitrary sub-class %a" Typ.Name.pp sub ;
+                let sub_pname = Procname.replace_class pname sub in
+                get sub_pname |> found_from_subclass sub_pname )
+        | _ ->
+            `NotFound ) )
+  in
+  fun pname -> get_summary_formals_aux pname

infer/src/IR/Tenv.mli

@@ -41,6 +41,7 @@ val mk_struct :
   -> ?exported_objc_methods:Procname.t list
   -> ?supers:Typ.Name.t list
   -> ?annots:Annot.Item.t
+  -> ?java_class_kind:Struct.java_class_kind
   -> ?dummy:bool
   -> Typ.Name.t
   -> Struct.t
@@ -65,4 +66,22 @@ val merge_per_file : src:per_file -> dst:per_file -> per_file
 (** Best-effort merge of [src] into [dst]. If a procedure is both in [dst] and [src], the one in
     [dst] will get overwritten. *)
 
+val get_summary_formals :
+     t
+  -> get_summary:(Procname.t -> 'summary option)
+  -> get_formals:(Procname.t -> 'formals option)
+  -> Procname.t
+  -> [ `NotFound
+     | `Found of 'summary * 'formals
+     | `FoundFromSubclass of Procname.t * 'summary * 'formals ]
+(** Get summary and formals of the given proc name with heuristics for finding a method in
+    non-abstract sub-classes
+
+    - If the class is an interface: Find its unique sub-class and apply the heuristics recursively.
+
+    - If the class is an abstract class: Find/use its own summary if possible. If not found, find
+      one (arbitrary but deterministic) summary from its sub-classes.
+
+    - Otherwise: Find its own summary. *)
+
 module SQLite : SqliteUtils.Data with type t = per_file

infer/src/cost/cost.ml

@@ -23,13 +23,12 @@ module Payload = SummaryPayload.Make (struct
   let field = Payloads.Fields.cost
 end)
 
-type callee_summary_and_formals = CostDomain.summary * (Pvar.t * Typ.t) list
-
 type extras_WorstCaseCost =
   { inferbo_invariant_map: BufferOverrunAnalysis.invariant_map
   ; integer_type_widths: Typ.IntegerWidths.t
   ; get_node_nb_exec: Node.id -> BasicCost.t
-  ; get_callee_summary_and_formals: Procname.t -> callee_summary_and_formals option }
+  ; get_summary: Procname.t -> CostDomain.summary option
+  ; get_formals: Procname.t -> (Pvar.t * Typ.t) list option }
 
 let instantiate_cost integer_type_widths ~inferbo_caller_mem ~callee_pname ~callee_formals ~params
     ~callee_cost ~loc =
@@ -62,7 +61,7 @@ module InstrBasicCost = struct
     match instr with
     | Sil.Call (ret, Exp.Const (Const.Cfun callee_pname), params, _, _) when Config.inclusive_cost
       ->
-        let {inferbo_invariant_map; integer_type_widths; get_callee_summary_and_formals} = extras in
+        let {inferbo_invariant_map; integer_type_widths; get_summary; get_formals} = extras in
         let operation_cost =
           match
             BufferOverrunAnalysis.extract_pre (InstrCFG.Node.id instr_node) inferbo_invariant_map
@@ -84,12 +83,23 @@ module InstrBasicCost = struct
                   in
                   CostDomain.of_operation_cost (model model_env ~ret inferbo_mem)
               | None -> (
-                match get_callee_summary_and_formals callee_pname with
+                match Tenv.get_summary_formals tenv ~get_summary ~get_formals callee_pname with
-                | Some ({CostDomain.post= callee_cost_record}, callee_formals) ->
+                | `Found ({CostDomain.post= callee_cost_record}, callee_formals) ->
                     CostDomain.map callee_cost_record ~f:(fun callee_cost ->
                         instantiate_cost integer_type_widths ~inferbo_caller_mem:inferbo_mem
                           ~callee_pname ~callee_formals ~params ~callee_cost ~loc )
-                | None ->
+                | `FoundFromSubclass
+                    (callee_pname, {CostDomain.post= callee_cost_record}, callee_formals) ->
+                    (* Note: It ignores top cost of subclass to avoid its propagations. *)
+                    let instantiated_cost =
+                      CostDomain.map callee_cost_record ~f:(fun callee_cost ->
+                          instantiate_cost integer_type_widths ~inferbo_caller_mem:inferbo_mem
+                            ~callee_pname ~callee_formals ~params ~callee_cost ~loc )
+                    in
+                    if BasicCost.is_top (CostDomain.get_operation_cost instantiated_cost) then
+                      CostDomain.unit_cost_atomic_operation
+                    else instantiated_cost
+                | `NotFound ->
                     CostDomain.unit_cost_atomic_operation ) )
         in
         if is_allocation_function callee_pname then
@@ -316,10 +326,10 @@ let compute_get_node_nb_exec node_cfg bound_map : get_node_nb_exec =
       ConstraintSolver.get_node_nb_exec equalities )
 
 
-let compute_worst_case_cost tenv integer_type_widths get_callee_summary_and_formals instr_cfg_wto
+let compute_worst_case_cost tenv integer_type_widths get_summary get_formals instr_cfg_wto
     inferbo_invariant_map get_node_nb_exec =
   let extras =
-    {inferbo_invariant_map; integer_type_widths; get_node_nb_exec; get_callee_summary_and_formals}
+    {inferbo_invariant_map; integer_type_widths; get_node_nb_exec; get_summary; get_formals}
   in
   WorstCaseCost.compute tenv extras instr_cfg_wto
 
@@ -366,14 +376,13 @@ let checker {Callbacks.exe_env; summary} : Summary.t =
   let is_on_ui_thread = ConcurrencyModels.runs_on_ui_thread ~attrs_of_pname tenv proc_name in
   let get_node_nb_exec = compute_get_node_nb_exec node_cfg bound_map in
   let astate =
-    let get_callee_summary_and_formals callee_pname =
+    let get_summary callee_pname = Payload.read ~caller_summary:summary ~callee_pname in
-      Payload.read_full ~caller_summary:summary ~callee_pname
+    let get_formals callee_pname =
-      |> Option.map ~f:(fun (callee_pdesc, callee_summary) ->
+      Ondemand.get_proc_desc callee_pname |> Option.map ~f:Procdesc.get_pvar_formals
-             (callee_summary, Procdesc.get_pvar_formals callee_pdesc) )
     in
     let instr_cfg = InstrCFG.from_pdesc proc_desc in
     let instr_cfg_wto = InstrCFG.wto instr_cfg in
-    compute_worst_case_cost tenv integer_type_widths get_callee_summary_and_formals instr_cfg_wto
+    compute_worst_case_cost tenv integer_type_widths get_summary get_formals instr_cfg_wto
       inferbo_invariant_map get_node_nb_exec
   in
   let () =

infer/src/java/jTransType.ml

@@ -320,11 +320,11 @@ and get_class_struct_typ =
     List.iter ~f:(fun cn -> ignore (get_class_struct_typ program tenv cn)) interface_names ;
     List.map ~f:typename_of_classname interface_names
   in
-  let make_struct program tenv node supers ~fields ~statics annots name =
+  let make_struct program tenv node supers ~fields ~statics annots ~java_class_kind name =
     let methods =
       Javalib.m_fold (fun m procnames -> translate_method_name program tenv m :: procnames) node []
     in
-    Tenv.mk_struct tenv ~fields ~statics ~methods ~supers ~annots name
+    Tenv.mk_struct tenv ~fields ~statics ~methods ~supers ~annots ~java_class_kind name
   in
   fun program tenv cn ->
     let name = typename_of_classname cn in
@@ -342,7 +342,8 @@ and get_class_struct_typ =
             let statics, _ = get_all_fields program tenv cn in
             let supers = create_super_list program tenv jinterface.Javalib.i_interfaces in
             let annots = JAnnotation.translate_item jinterface.Javalib.i_annotations in
-            make_struct program tenv node supers ~fields:[] ~statics annots name
+            make_struct program tenv node supers ~fields:[] ~statics annots
+              ~java_class_kind:Struct.Interface name
         | Some (Javalib.JClass jclass as node) ->
             let statics, fields =
               let classpath_static, classpath_nonstatic = get_all_fields program tenv cn in
@@ -359,7 +360,10 @@ and get_class_struct_typ =
                   let super_classname = typename_of_classname super_cn in
                   super_classname :: interface_list
             in
-            make_struct program tenv node supers ~fields ~statics annots name )
+            let java_class_kind =
+              if jclass.Javalib.c_abstract then Struct.AbstractClass else Struct.NormalClass
+            in
+            make_struct program tenv node supers ~fields ~statics annots ~java_class_kind name )
 
 
 let get_class_type_no_pointer program tenv cn =

infer/tests/codetoanalyze/java/performance/InheritanceTest.java

@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+class InheritanceTest {
+  interface MyInterface {
+    public void foo(int x);
+  }
+
+  class UniqueImpl implements MyInterface {
+    public void foo(int x) {
+      for (int i = 0; i < x; i++) {}
+    }
+  }
+
+  public void call_interface_method_linear(MyInterface c, int x) {
+    c.foo(x);
+  }
+
+  interface MyInterface2 {
+    public void foo(int x);
+  }
+
+  abstract class AbsImpl implements MyInterface2 {
+    public abstract void foo(int x);
+  }
+
+  class Impl1 extends AbsImpl {
+    @Override
+    public void foo(int x) {
+      for (int i = 0; i < x; i++) {}
+    }
+  }
+
+  class Impl2 extends AbsImpl {
+    @Override
+    public void foo(int x) {}
+  }
+
+  /* By heuristics, [Impl1.foo] is selected. It is hard to say good or bad. */
+  public void call_interface_method2_linear(MyInterface2 c, int x) {
+    c.foo(x);
+  }
+
+  interface MyInterface3 {
+    public int unknown();
+  }
+
+  interface MyInterface4 {
+    public void top_cost(MyInterface3 x);
+  }
+
+  class UniqueImpl4 implements MyInterface4 {
+    public void top_cost(MyInterface3 i3) {
+      for (int i = 0; i < i3.unknown(); i++) {}
+    }
+  }
+
+  public void ignore_top_costed_sub_method_constant(MyInterface3 i3, MyInterface4 i4) {
+    i4.top_cost(i3);
+  }
+}

infer/tests/codetoanalyze/java/performance/issues.exp

@@ -119,6 +119,12 @@ codetoanalyze/java/performance/Cost_test_deps.java, codetoanalyze.java.performan
 codetoanalyze/java/performance/Cost_test_deps.java, codetoanalyze.java.performance.Cost_test_deps.two_loops():int, 6, EXPENSIVE_EXECUTION_TIME, no_bucket, ERROR, [with estimated cost 545, O(1), degree = 0]
 codetoanalyze/java/performance/EvilCfg.java, EvilCfg.foo(int,int,boolean):void, 0, INFINITE_EXECUTION_TIME, no_bucket, ERROR, [Unbounded loop,Loop at line 15]
 codetoanalyze/java/performance/FieldAccess.java, codetoanalyze.java.performance.FieldAccess.iterate_upto_field_size(codetoanalyze.java.performance.FieldAccess$Test):void, 0, EXPENSIVE_EXECUTION_TIME, no_bucket, ERROR, [with estimated cost 2 + 6 ⋅ test.a, O(test.a), degree = 1,{test.a},Loop at line 16]
+codetoanalyze/java/performance/InheritanceTest.java, InheritanceTest$Impl1.foo(int):void, 0, EXPENSIVE_EXECUTION_TIME, no_bucket, ERROR, [with estimated cost 2 + 5 ⋅ x, O(x), degree = 1,{x},Loop at line 34]
+codetoanalyze/java/performance/InheritanceTest.java, InheritanceTest$UniqueImpl.foo(int):void, 0, EXPENSIVE_EXECUTION_TIME, no_bucket, ERROR, [with estimated cost 2 + 5 ⋅ x, O(x), degree = 1,{x},Loop at line 15]
+codetoanalyze/java/performance/InheritanceTest.java, InheritanceTest$UniqueImpl4.top_cost(InheritanceTest$MyInterface3):void, 0, INFINITE_EXECUTION_TIME, no_bucket, ERROR, [Unbounded loop,Loop at line 58]
+codetoanalyze/java/performance/InheritanceTest.java, InheritanceTest$UniqueImpl4.top_cost(InheritanceTest$MyInterface3):void, 0, INTEGER_OVERFLOW_L5, no_bucket, ERROR, [<LHS trace>,Assignment,Binary operation: ([0, +oo] + 1):signed32]
+codetoanalyze/java/performance/InheritanceTest.java, InheritanceTest.call_interface_method2_linear(InheritanceTest$MyInterface2,int):void, 0, EXPENSIVE_EXECUTION_TIME, no_bucket, ERROR, [with estimated cost 8 + 5 ⋅ x, O(x), degree = 1,{x},call to void InheritanceTest$Impl1.foo(int),Loop at line 34]
+codetoanalyze/java/performance/InheritanceTest.java, InheritanceTest.call_interface_method_linear(InheritanceTest$MyInterface,int):void, 0, EXPENSIVE_EXECUTION_TIME, no_bucket, ERROR, [with estimated cost 8 + 5 ⋅ x, O(x), degree = 1,{x},call to void InheritanceTest$UniqueImpl.foo(int),Loop at line 15]
 codetoanalyze/java/performance/IntTest.java, IntTest.control_var_band_add_constant(int,int):void, 2, INTEGER_OVERFLOW_L5, no_bucket, ERROR, [<LHS trace>,Parameter `x`,Binary operation: ([-oo, +oo] + 1):signed32]
 codetoanalyze/java/performance/IntTest.java, IntTest.control_var_band_add_constant(int,int):void, 4, INTEGER_OVERFLOW_L5, no_bucket, ERROR, [<LHS trace>,Parameter `x`,Binary operation: ([-oo, +oo] + 1):signed32]
 codetoanalyze/java/performance/IntTest.java, IntTest.intValue_linear(java.lang.Integer):void, 0, EXPENSIVE_EXECUTION_TIME, no_bucket, ERROR, [with estimated cost 2 + 5 ⋅ mKBytesToSend + 3 ⋅ (1+max(0, mKBytesToSend)), O(mKBytesToSend), degree = 1,{1+max(0, mKBytesToSend)},Loop at line 9,{mKBytesToSend},Loop at line 9]