[retain cycles] Define custom compare function that is more suited to dedup cycles

Reviewed By: mbouaziz

Differential Revision: D7517385

fbshipit-source-id: 00e0433

infer/src/biabduction/RetainCyclesType.ml

@@ -8,24 +8,48 @@
  *)
 open! IStd
 
-type retain_cycle_node = {rc_node_exp: Exp.t; rc_node_typ: Typ.t} [@@deriving compare]
+type retain_cycle_node = {rc_node_exp: Exp.t; rc_node_typ: Typ.t}
 
-type retain_cycle_field_objc =
+type retain_cycle_field = {rc_field_name: Typ.Fieldname.t; rc_field_inst: Sil.inst}
-  {rc_field_name: Typ.Fieldname.t; rc_field_inst: Sil.inst}
-  [@@deriving compare]
 
-type retain_cycle_edge_objc =
+type retain_cycle_edge_obj = {rc_from: retain_cycle_node; rc_field: retain_cycle_field}
-  {rc_from: retain_cycle_node; rc_field: retain_cycle_field_objc}
-  [@@deriving compare]
 
-type retain_cycle_edge =
+type retain_cycle_edge = Object of retain_cycle_edge_obj | Block of Typ.Procname.t * Pvar.t
-  | Object of retain_cycle_edge_objc
-  | Block of Typ.Procname.t * Pvar.t
-  [@@deriving compare]
 
-let retain_cycle_edge_equal = [%compare.equal : retain_cycle_edge]
+type t = {rc_head: retain_cycle_edge; rc_elements: retain_cycle_edge list}
+
+let compare_retain_cycle_node (node1: retain_cycle_node) (node2: retain_cycle_node) =
+  Typ.compare node1.rc_node_typ node2.rc_node_typ
+
+
+let compare_retain_cycle_field (node1: retain_cycle_field) (node2: retain_cycle_field) =
+  Typ.Fieldname.compare node1.rc_field_name node2.rc_field_name
+
+
+let compare_retain_cycle_edge_obj (obj1: retain_cycle_edge_obj) (obj2: retain_cycle_edge_obj) =
+  let obj1_pair = Tuple.T2.create obj1.rc_from obj1.rc_field in
+  let obj2_pair = Tuple.T2.create obj2.rc_from obj2.rc_field in
+  Tuple.T2.compare ~cmp1:compare_retain_cycle_node ~cmp2:compare_retain_cycle_field obj1_pair
+    obj2_pair
+
+
+let compare_retain_cycle_edge (edge1: retain_cycle_edge) (edge2: retain_cycle_edge) =
+  match (edge1, edge2) with
+  | Object edge_obj1, Object edge_obj2 ->
+      compare_retain_cycle_edge_obj edge_obj1 edge_obj2
+  | Block (procname1, _), Block (procname2, _) ->
+      Typ.Procname.compare procname1 procname2
+  | Object _, Block _ ->
+      1
+  | Block _, Object _ ->
+      -1
+
+
+let equal_retain_cycle_edge = [%compare.equal : retain_cycle_edge]
+
+let compare (rc1: t) (rc2: t) =
+  List.compare compare_retain_cycle_edge rc1.rc_elements rc2.rc_elements
 
-type t = {rc_head: retain_cycle_edge; rc_elements: retain_cycle_edge list} [@@deriving compare]
 
 module Set = Caml.Set.Make (struct
   type nonrec t = t
@@ -45,7 +69,7 @@ let _retain_cycle_node_to_string (node: retain_cycle_node) =
   Format.sprintf "%s : %s" (Exp.to_string node.rc_node_exp) (Typ.to_string node.rc_node_typ)
 
 
-let retain_cycle_field_to_string (field: retain_cycle_field_objc) =
+let retain_cycle_field_to_string (field: retain_cycle_field) =
   Format.sprintf "%s[%s]"
     (Typ.Fieldname.to_string field.rc_field_name)
     (Sil.inst_to_string field.rc_field_inst)
@@ -76,7 +100,7 @@ let find_minimum_element cycle =
 let shift cycle head : t =
   let rec shift_elements rev_tail elements =
     match elements with
-    | hd :: rest when not (retain_cycle_edge_equal hd head) ->
+    | hd :: rest when not (equal_retain_cycle_edge hd head) ->
         shift_elements (hd :: rev_tail) rest
     | _ ->
         elements @ List.rev rev_tail

infer/src/biabduction/RetainCyclesType.mli

@@ -11,11 +11,11 @@ open! IStd
 
 type retain_cycle_node = {rc_node_exp: Exp.t; rc_node_typ: Typ.t}
 
-type retain_cycle_field_objc = {rc_field_name: Typ.Fieldname.t; rc_field_inst: Sil.inst}
+type retain_cycle_field = {rc_field_name: Typ.Fieldname.t; rc_field_inst: Sil.inst}
 
-type retain_cycle_edge_objc = {rc_from: retain_cycle_node; rc_field: retain_cycle_field_objc}
+type retain_cycle_edge_obj = {rc_from: retain_cycle_node; rc_field: retain_cycle_field}
 
-type retain_cycle_edge = Object of retain_cycle_edge_objc | Block of Typ.Procname.t * Pvar.t
+type retain_cycle_edge = Object of retain_cycle_edge_obj | Block of Typ.Procname.t * Pvar.t
 
 (** A retain cycle is a non-empty list of paths. It also contains a pointer to the head of the list
 to model the cycle structure. The next element from the end of the list is the head. *)

infer/tests/codetoanalyze/objc/errors/Makefile

@@ -96,6 +96,7 @@ SOURCES_ARC = \
 	memory_leaks_benchmark/RetainCycleBlocks.m \
 	memory_leaks_benchmark/RetainCyclePropertyInProtocol.m \
 	memory_leaks_benchmark/RetainCycleBlockCapturedVar.m \
+	memory_leaks_benchmark/RetainCycleDeduplication.m \
   npe/BoxedNumberExample.m \
   npe/ObjCMethodCallInCondition.m \
   npe/UpdateDict.m \

infer/tests/codetoanalyze/objc/errors/issues.exp

@@ -33,6 +33,7 @@ codetoanalyze/objc/errors/memory_leaks_benchmark/RetainCycleBlockCapturedVar.m,
 codetoanalyze/objc/errors/memory_leaks_benchmark/RetainCycleBlocks.m, RCBlock_retain_self_in_block, 1, RETAIN_CYCLE, ERROR, [start of procedure retain_self_in_block,Executing synthesized setter setHandler:]
 codetoanalyze/objc/errors/memory_leaks_benchmark/RetainCycleBlocks.m, objc_blockretain_a_in_block_cycle_3, 1, RETAIN_CYCLE, ERROR, [start of procedure block,Executing synthesized setter setChild:]
 codetoanalyze/objc/errors/memory_leaks_benchmark/RetainCycleBlocks.m, retain_a_in_block_cycle, 4, RETAIN_CYCLE, ERROR, [start of procedure retain_a_in_block_cycle(),Executing synthesized setter setB:,Executing synthesized setter setA:]
+codetoanalyze/objc/errors/memory_leaks_benchmark/RetainCycleDeduplication.m, CViewController_setCaptureInteractionController:, 4, RETAIN_CYCLE, ERROR, [start of procedure setCaptureInteractionController:,Condition is true,Executing synthesized setter setDelegate:,Executing synthesized setter setDelegate:]
 codetoanalyze/objc/errors/memory_leaks_benchmark/RetainCyclePropertyInProtocol.m, MyCustomViewController_loadViewBad, 3, RETAIN_CYCLE, ERROR, [start of procedure loadViewBad,Executing synthesized setter setView:,Executing synthesized setter setStrong_delegate:]
 codetoanalyze/objc/errors/memory_leaks_benchmark/retain_cycle.m, strongcycle, 6, RETAIN_CYCLE, ERROR, [start of procedure strongcycle(),Executing synthesized setter setB:,Executing synthesized setter setA:]
 codetoanalyze/objc/errors/memory_leaks_benchmark/retain_cycle2.m, strongcycle2, 4, RETAIN_CYCLE, ERROR, [start of procedure strongcycle2(),start of procedure init,return from a call to Parent_init,start of procedure init,return from a call to Child_init,start of procedure setChild:,return from a call to Parent_setChild:,start of procedure setParent:,return from a call to Child_setParent:]

infer/tests/codetoanalyze/objc/errors/memory_leaks_benchmark/RetainCycleDeduplication.m

@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2018 - present Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+#import <Foundation/NSObject.h>
+
+@interface CaptureController : NSObject
+
+@property(nonatomic, strong, readwrite) id delegate;
+
+@end
+
+@implementation CaptureController
+
+@end
+
+@interface CViewController : NSObject
+
+@property(nonatomic, strong) CaptureController* captureController;
+
+@end
+
+@implementation CViewController
+
+- (void)setCaptureInteractionController:(CaptureController*)captureController {
+  if (_captureController != captureController) {
+    _captureController.delegate = nil;
+    _captureController = captureController;
+    _captureController.delegate = self;
+  }
+}
+
+@end