[clang] Adding implicit implementation of dealloc methods to ObjC cla…

…sses

Summary:
This models ARC implementation of dealloc, see https://clang.llvm.org/docs/AutomaticReferenceCounting.html#dealloc. Dealloc methods can be added to ObjC classes to free C memory for example, but the deallocation of the ObjC instance variables of the object is done automatically. So here we add this explicitly to Infer:
1. First, we add an empty dealloc method when it is not written explicitly.
2. For each dealloc method (including the implicitly added ones) we add calls to dealloc of the ObjC instance variables.

Reviewed By: jvillard

Differential Revision: D21883546

fbshipit-source-id: f5d4930f2

infer/src/IR/Procname.ml

@@ -439,6 +439,12 @@ let is_objc_method procname =
   match procname with ObjC_Cpp name -> ObjC_Cpp.is_objc_method name | _ -> false
 
 
+let is_objc_dealloc procname =
+  is_objc_method procname
+  &&
+  match procname with ObjC_Cpp {method_name} -> ObjC_Cpp.is_objc_dealloc method_name | _ -> false
+
+
 let block_name_of_procname procname =
   match procname with
   | Block block ->

infer/src/IR/Procname.mli

@@ -278,6 +278,9 @@ val get_method : t -> string
 val is_objc_block : t -> bool
 (** Return whether the procname is a block procname. *)
 
+val is_objc_dealloc : t -> bool
+(** Return whether the dealloc method of an Objective-C class. *)
+
 val is_c_method : t -> bool
 (** Return true this is an Objective-C/C++ method name. *)
 

infer/src/clang/CAddImplicitDeallocImpl.ml

@@ -0,0 +1,81 @@
+(*
+ * 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.
+ *)
+
+open! IStd
+
+let get_dealloc_call_field (self_var, self_typ) location instrs (fieldname, field_typ, _) =
+  match field_typ.Typ.desc with
+  | Typ.Tptr (({desc= Tstruct name} as cls), Pk_pointer) when Typ.is_objc_class cls ->
+      let field_class_dealloc_name = Procname.make_objc_dealloc name in
+      let id_pvar = Ident.create_fresh Ident.knormal in
+      let load_pvar_instr =
+        Sil.Load {id= id_pvar; e= Lvar self_var; root_typ= self_typ; typ= self_typ; loc= location}
+      in
+      let id_field = Ident.create_fresh Ident.knormal in
+      let class_typ = match self_typ.Typ.desc with Typ.Tptr (t, _) -> t | _ -> self_typ in
+      let e = Exp.Lfield (Var id_pvar, fieldname, class_typ) in
+      let load_field_instr =
+        Sil.Load {id= id_field; e; root_typ= field_typ; typ= field_typ; loc= location}
+      in
+      let ret_id = Ident.create_fresh Ident.knormal in
+      let call_instr =
+        Sil.Call
+          ( (ret_id, Typ.void)
+          , Const (Cfun field_class_dealloc_name)
+          , [(Var id_field, field_typ)]
+          , location
+          , CallFlags.default )
+      in
+      instrs @ [load_pvar_instr; load_field_instr; call_instr]
+  | _ ->
+      instrs
+
+
+let process_dealloc proc_desc fields self =
+  let exit_node = Procdesc.get_exit_node proc_desc in
+  let location = Procdesc.Node.get_last_loc exit_node in
+  let fields_dealloc_call_instrs =
+    List.fold ~f:(get_dealloc_call_field self location) ~init:[] fields
+  in
+  let exit_pred_nodes = Procdesc.Node.get_preds exit_node in
+  let node_name = Procdesc.Node.Call CFrontend_config.dealloc in
+  let node_kind = Procdesc.Node.Stmt_node node_name in
+  let dealloc_calls_node =
+    Procdesc.create_node proc_desc location node_kind fields_dealloc_call_instrs
+  in
+  Procdesc.node_set_succs proc_desc dealloc_calls_node ~normal:[exit_node] ~exn:[] ;
+  List.iter
+    ~f:(fun node -> Procdesc.node_set_succs proc_desc node ~normal:[dealloc_calls_node] ~exn:[])
+    exit_pred_nodes
+
+
+let process_procdesc tenv proc_name proc_desc =
+  let get_struct_procname tenv proc_name =
+    match Procname.get_class_type_name proc_name with
+    | Some name ->
+        Tenv.lookup tenv name
+    | None ->
+        None
+  in
+  if Procdesc.is_defined proc_desc && Procname.is_objc_dealloc proc_name then
+    let struct_opt = get_struct_procname tenv proc_name in
+    match struct_opt with
+    | Some {fields} -> (
+        let formals = Procdesc.get_formals proc_desc in
+        let self = List.find ~f:(fun (var, _) -> Mangled.equal var Mangled.self) formals in
+        match self with
+        | Some (self, typ) ->
+            let self_var = Pvar.mk self proc_name in
+            process_dealloc proc_desc fields (self_var, typ)
+        | None ->
+            () )
+    | _ ->
+        ()
+  else ()
+
+
+let process cfg tenv = Procname.Hash.iter (process_procdesc tenv) cfg

infer/src/clang/CAddImplicitDeallocImpl.mli

@@ -0,0 +1,18 @@
+(*
+ * 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.
+ *)
+
+open! IStd
+
+val process : Cfg.t -> Tenv.t -> unit
+(** This models ARC implementation of dealloc, see
+    https://clang.llvm.org/docs/AutomaticReferenceCounting.html#dealloc. Dealloc methods can be
+    added to ObjC classes to free C memory for example, but the deallocation of the ObjC instance
+    variables of the object is done automatically. So here we add this explicitely to Infer: we add
+    calls to dealloc of the ObjC instance variables. Here we assume that every ObjC class has
+    already a dealloc method, because if it doesn't exist we add an empty method in
+    CFrontend_decl.create_and_process_dealloc_objc_impl TODO(T68411500): add calls to dealloc of the
+    superclass. *)

infer/src/clang/ast_expressions.mli

@@ -14,6 +14,8 @@ val create_pointer_qual_type : ?quals:Typ.type_quals -> qual_type -> qual_type
 
 val create_reference_qual_type : ?quals:Typ.type_quals -> qual_type -> qual_type
 
+val create_void_type : qual_type
+
 val create_char_star_type : ?quals:Typ.type_quals -> unit -> qual_type
 
 val make_next_object_exp :

infer/src/clang/cFrontend.ml

@@ -50,6 +50,7 @@ let do_source_file (translation_unit_context : CFrontend_config.translation_unit
   L.(debug Capture Verbose)
     "@\n Start building call/cfg graph for '%a'....@\n" SourceFile.pp source_file ;
   let cfg = compute_icfg translation_unit_context tenv ast in
+  CAddImplicitDeallocImpl.process cfg tenv ;
   L.(debug Capture Verbose) "@\n End building call/cfg graph for '%a'.@\n" SourceFile.pp source_file ;
   NullabilityPreanalysis.analysis cfg tenv ;
   SourceFiles.add source_file cfg (Tenv.FileLocal tenv) (Some integer_type_widths) ;

infer/src/clang/cFrontend_config.ml

@@ -22,6 +22,8 @@ type decl_trans_context = [`DeclTraversal | `Translation]
 
 let alloc = "alloc"
 
+let dealloc = "dealloc"
+
 let assert_fail = "__assert_fail"
 
 let assert_rtn = "__assert_rtn"

infer/src/clang/cFrontend_config.mli

@@ -22,6 +22,8 @@ type decl_trans_context = [`DeclTraversal | `Translation]
 
 val alloc : string
 
+val dealloc : string
+
 val assert_fail : string
 
 val assert_rtn : string

infer/src/clang/cFrontend_decl.ml

@@ -239,6 +239,56 @@ module CFrontend_decl_funct (T : CModule_type.CTranslation) : CModule_type.CFron
     List.iter ~f:(process_one_method_decl trans_unit_ctx tenv cfg curr_class) decl_list
 
 
+  (* Here we add an empty dealloc method to every ObjC class if it doesn't have one. Then the implicit
+     implementation of such method will be added in CAddImplicitDeallocImpl.process *)
+  let create_and_process_dealloc_objc_impl trans_unit_ctx tenv cfg curr_class objc_class_decl_info
+      decl_list =
+    let open Clang_ast_t in
+    let found_dealloc =
+      List.exists
+        ~f:(fun decl ->
+          match decl with
+          | ObjCMethodDecl (_, name_info, mdi) ->
+              String.equal name_info.ni_name "dealloc" && mdi.Clang_ast_t.omdi_is_instance_method
+          | _ ->
+              false )
+        decl_list
+    in
+    if not found_dealloc then
+      let name_info =
+        {ni_name= CFrontend_config.dealloc; ni_qual_name= [CFrontend_config.dealloc]}
+      in
+      let decl_info =
+        { di_pointer= CAst_utils.get_fresh_pointer ()
+        ; di_parent_pointer= Some objc_class_decl_info.Clang_ast_t.di_pointer
+        ; di_source_range= objc_class_decl_info.Clang_ast_t.di_source_range
+        ; di_owning_module= objc_class_decl_info.Clang_ast_t.di_owning_module
+        ; di_is_hidden= true
+        ; di_is_implicit= true
+        ; di_is_used= true
+        ; di_is_this_declaration_referenced= false
+        ; di_is_invalid_decl= false
+        ; di_attributes= []
+        ; di_full_comment= None
+        ; di_access= `None }
+      in
+      let obj_c_method_decl_info =
+        { omdi_is_instance_method= true
+        ; omdi_result_type= Ast_expressions.create_void_type
+        ; omdi_is_property_accessor= false
+        ; omdi_property_decl= None
+        ; omdi_parameters= []
+        ; omdi_implicit_parameters= []
+        ; omdi_is_variadic= false
+        ; omdi_is_overriding= true
+        ; omdi_is_optional= false
+        ; omdi_body= Some (Clang_ast_t.CompoundStmt (CAst_utils.dummy_stmt_info (), []))
+        ; omdi_mangled_name= CFrontend_config.dealloc }
+      in
+      let method_decl = ObjCMethodDecl (decl_info, name_info, obj_c_method_decl_info) in
+      process_method_decl trans_unit_ctx tenv cfg curr_class method_decl
+
+
   (** Given REVERSED list of method qualifiers (method_name::class_name::rest_quals), return whether
       method should be translated based on method and class whitelists *)
   let is_whitelisted_cpp_method =
@@ -332,13 +382,15 @@ module CFrontend_decl_funct (T : CModule_type.CTranslation) : CModule_type.CFron
             (ObjcCategory_decl.category_impl_decl CType_decl.qual_type_to_sil_type
                CType_decl.CProcname.from_decl tenv dec) ;
           process_methods trans_unit_ctx tenv cfg curr_class decl_list
-      | ObjCImplementationDecl (_, _, decl_list, _, _) ->
+      | ObjCImplementationDecl (objc_class_decl_info, _, decl_list, _, _) ->
           let curr_class = CContext.ContextClsDeclPtr dec_ptr in
           let qual_type_to_sil_type = CType_decl.qual_type_to_sil_type in
           ignore
             (ObjcInterface_decl.interface_impl_declaration qual_type_to_sil_type
                CType_decl.CProcname.from_decl tenv dec) ;
-          process_methods trans_unit_ctx tenv cfg curr_class decl_list
+          process_methods trans_unit_ctx tenv cfg curr_class decl_list ;
+          create_and_process_dealloc_objc_impl trans_unit_ctx tenv cfg curr_class
+            objc_class_decl_info decl_list
       | CXXMethodDecl (decl_info, _, _, _, _)
       | CXXConstructorDecl (decl_info, _, _, _, _)
       | CXXConversionDecl (decl_info, _, _, _, _)

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

@@ -20,7 +20,7 @@ codetoanalyze/objc/shared/block/BlockVar.m, BlockVar.blockPostBad, 5, NULL_DEREF
 codetoanalyze/objc/shared/block/BlockVar.m, BlockVar.capturedNullDeref, 5, NULL_DEREFERENCE, no_bucket, ERROR, [start of procedure capturedNullDeref,start of procedure block]
 codetoanalyze/objc/shared/block/BlockVar.m, BlockVar.navigateToURLInBackground, 8, NULL_DEREFERENCE, B1, ERROR, [start of procedure navigateToURLInBackground,start of procedure block,start of procedure test,return from a call to BlockVar.test,return from a call to objc_blockBlockVar.navigateToURLInBackground_1,Taking true branch]
 codetoanalyze/objc/shared/block/block.m, main1, 30, DIVIDE_BY_ZERO, no_bucket, ERROR, [start of procedure main1(),start of procedure block,start of procedure block,return from a call to objc_blockobjc_blockmain1_2_3,return from a call to objc_blockmain1_2,start of procedure block,return from a call to objc_blockmain1_1]
-codetoanalyze/objc/shared/block/block_no_args.m, My_manager.m, 10, NULL_DEREFERENCE, B1, ERROR, [start of procedure m,start of procedure block,return from a call to objc_blockMy_manager.m_1,Taking true branch]
+codetoanalyze/objc/shared/block/block_no_args.m, Block_no_args.m, 10, NULL_DEREFERENCE, B1, ERROR, [start of procedure m,start of procedure block,return from a call to objc_blockBlock_no_args.m_1,Taking true branch]
 codetoanalyze/objc/shared/category_procdesc/main.c, CategoryProcdescMain, 3, MEMORY_LEAK, no_bucket, ERROR, [start of procedure CategoryProcdescMain(),Skipping performDaysWork: method has no implementation]
 codetoanalyze/objc/shared/field_superclass/SuperExample.m, ASuper.init, 2, NULL_DEREFERENCE, B2, ERROR, [start of procedure init]
 codetoanalyze/objc/biabduction/blocks_in_heap/BlockInHeap.m, block_in_heap_executed_after_bi_abduction_ok_test, 3, NULL_DEREFERENCE, B1, ERROR, [start of procedure block_in_heap_executed_after_bi_abduction_ok_test(),start of procedure block_in_heap_executed_after_bi_abduction_ok_no_retain_cycle(),start of procedure assign_block_to_ivar,Executing synthesized setter setHandler:,return from a call to BlockInHeap.assign_block_to_ivar,Executing synthesized getter handler,start of procedure block,return from a call to objc_blockBlockInHeap.assign_block_to_ivar_1,return from a call to block_in_heap_executed_after_bi_abduction_ok_no_retain_cycle,Taking true branch]
@@ -107,8 +107,8 @@ codetoanalyze/objc/biabduction/property/main.c, property_main, 3, MEMORY_LEAK, n
 codetoanalyze/objc/biabduction/resource_leaks/Dispatch_sources.m, ProcessContentsOfFile, 35, RESOURCE_LEAK, no_bucket, ERROR, [start of procedure ProcessContentsOfFile(),Taking false branch,Skipping dispatch_get_global_queue(): method has no implementation,Skipping dispatch_source_create(): method has no implementation,Taking false branch,Skipping dispatch_source_set_event_handler(): method has no implementation,Skipping dispatch_source_set_cancel_handler(): method has no implementation]
 codetoanalyze/objc/biabduction/resource_leaks/Dispatch_sources.m, objc_blockProcessContentsOfFile_2, 6, MEMORY_LEAK, no_bucket, ERROR, [start of procedure block,Skipping dispatch_source_get_data(): method has no implementation,Taking true branch,Skipping MyProcessFileData(): method has no implementation]
 codetoanalyze/objc/biabduction/resource_leaks/ResourceLeakExample.m, NSFileHandle.fileHandleForLoggingAtPath:mode:, 9, RESOURCE_LEAK, no_bucket, ERROR, [start of procedure fileHandleForLoggingAtPath:mode:,Taking true branch,Skipping fileSystemRepresentation: method has no implementation,Taking false branch,Taking true branch,Skipping autorelease: no implementation found for method declared in Objective-C protocol]
-codetoanalyze/objc/shared/annotations/nonnull_annotations.m, A.test1:, 2, PARAMETER_NOT_NULL_CHECKED, B2, WARNING, [start of procedure test1:,Message child with receiver nil returns nil.]
-codetoanalyze/objc/shared/annotations/nonnull_annotations.m, A.test3:, 1, PARAMETER_NOT_NULL_CHECKED, B1, WARNING, [start of procedure test3:]
+codetoanalyze/objc/shared/annotations/nonnull_annotations.m, NonnullAnnot.test1:, 2, PARAMETER_NOT_NULL_CHECKED, B2, WARNING, [start of procedure test1:,Message child with receiver nil returns nil.]
+codetoanalyze/objc/shared/annotations/nonnull_annotations.m, NonnullAnnot.test3:, 1, PARAMETER_NOT_NULL_CHECKED, B1, WARNING, [start of procedure test3:]
 codetoanalyze/objc/shared/annotations/nullable_annotations.m, User.otherUserName, 2, NULL_DEREFERENCE, B2, ERROR, [start of procedure otherUserName,Skipping otherUser: method has no implementation]
 codetoanalyze/objc/shared/annotations/nullable_annotations.m, npe_property_nullable, 3, NULL_DEREFERENCE, B1, ERROR, [start of procedure npe_property_nullable(),Skipping child: method has no implementation]
 codetoanalyze/objc/shared/annotations/nullable_annotations_fields.m, A.nullable_field, 3, NULL_DEREFERENCE, B1, ERROR, [start of procedure nullable_field,Skipping getA(): method has no implementation]

infer/tests/codetoanalyze/objc/frontend/block/retain_cycle.m.dot

@@ -60,6 +60,28 @@ digraph cfg {
 
 
 	 "capture#A#instance.d411336575e4bf632a1828f5f5979726_4" -> "capture#A#instance.d411336575e4bf632a1828f5f5979726_3" ;
+"dealloc#A#instance.55ac864e91dcd5d484e8ab7d8eb94fcb_1" [label="1: Start A.dealloc\nFormals:  self:A*\nLocals:  \n  " color=yellow style=filled]
+
+
+	 "dealloc#A#instance.55ac864e91dcd5d484e8ab7d8eb94fcb_1" -> "dealloc#A#instance.55ac864e91dcd5d484e8ab7d8eb94fcb_3" ;
+"dealloc#A#instance.55ac864e91dcd5d484e8ab7d8eb94fcb_2" [label="2: Exit A.dealloc \n  " color=yellow style=filled]
+
+
+"dealloc#A#instance.55ac864e91dcd5d484e8ab7d8eb94fcb_3" [label="3:  Call dealloc \n   n$0=*&self:A* [line 50, column 1]\n  n$1=*n$0._data:D* [line 50, column 1]\n  n$2=_fun_D.dealloc(n$1:D*) [line 50, column 1]\n  n$3=*&self:A* [line 50, column 1]\n  n$4=*n$3._b:B* [line 50, column 1]\n  n$5=_fun_B.dealloc(n$4:B*) [line 50, column 1]\n " shape="box"]
+
+
+	 "dealloc#A#instance.55ac864e91dcd5d484e8ab7d8eb94fcb_3" -> "dealloc#A#instance.55ac864e91dcd5d484e8ab7d8eb94fcb_2" ;
+"dealloc#B#instance.8757740e0d47129962d40fbccbdf4d3f_1" [label="1: Start B.dealloc\nFormals:  self:B*\nLocals:  \n  " color=yellow style=filled]
+
+
+	 "dealloc#B#instance.8757740e0d47129962d40fbccbdf4d3f_1" -> "dealloc#B#instance.8757740e0d47129962d40fbccbdf4d3f_3" ;
+"dealloc#B#instance.8757740e0d47129962d40fbccbdf4d3f_2" [label="2: Exit B.dealloc \n  " color=yellow style=filled]
+
+
+"dealloc#B#instance.8757740e0d47129962d40fbccbdf4d3f_3" [label="3:  Call dealloc \n   n$6=*&self:B* [line 31, column 1]\n  n$7=*n$6._d:D* [line 31, column 1]\n  n$8=_fun_D.dealloc(n$7:D*) [line 31, column 1]\n " shape="box"]
+
+
+	 "dealloc#B#instance.8757740e0d47129962d40fbccbdf4d3f_3" -> "dealloc#B#instance.8757740e0d47129962d40fbccbdf4d3f_2" ;
 "sHandler:#B#instance.590685250eb38eaab242405cd45c572b_1" [label="1: Start B.sHandler:\nFormals:  self:B* h:_fn_(*)\nLocals:  \n  " color=yellow style=filled]
 
 

infer/tests/codetoanalyze/objc/frontend/block/static.m.dot

@@ -115,4 +115,15 @@ digraph cfg {
 
 
 	 "test_leak#A#class.8240788aa53244827857be0e92d27671_3" -> "test_leak#A#class.8240788aa53244827857be0e92d27671_2" ;
+"dealloc#A#instance.55ac864e91dcd5d484e8ab7d8eb94fcb_1" [label="1: Start A.dealloc\nFormals:  self:A*\nLocals:  \n  " color=yellow style=filled]
+
+
+	 "dealloc#A#instance.55ac864e91dcd5d484e8ab7d8eb94fcb_1" -> "dealloc#A#instance.55ac864e91dcd5d484e8ab7d8eb94fcb_3" ;
+"dealloc#A#instance.55ac864e91dcd5d484e8ab7d8eb94fcb_2" [label="2: Exit A.dealloc \n  " color=yellow style=filled]
+
+
+"dealloc#A#instance.55ac864e91dcd5d484e8ab7d8eb94fcb_3" [label="3:  Call dealloc \n  " shape="box"]
+
+
+	 "dealloc#A#instance.55ac864e91dcd5d484e8ab7d8eb94fcb_3" -> "dealloc#A#instance.55ac864e91dcd5d484e8ab7d8eb94fcb_2" ;
 }

infer/tests/codetoanalyze/objc/frontend/boxing/Boxing.m.dot

@@ -1,5 +1,16 @@
 /* @generated */
 digraph cfg {
+"dealloc#Boxing#instance.569d9054e725a069b00d4e2aa3ade22c_1" [label="1: Start Boxing.dealloc\nFormals:  self:Boxing*\nLocals:  \n  " color=yellow style=filled]
+
+
+	 "dealloc#Boxing#instance.569d9054e725a069b00d4e2aa3ade22c_1" -> "dealloc#Boxing#instance.569d9054e725a069b00d4e2aa3ade22c_3" ;
+"dealloc#Boxing#instance.569d9054e725a069b00d4e2aa3ade22c_2" [label="2: Exit Boxing.dealloc \n  " color=yellow style=filled]
+
+
+"dealloc#Boxing#instance.569d9054e725a069b00d4e2aa3ade22c_3" [label="3:  Call dealloc \n  " shape="box"]
+
+
+	 "dealloc#Boxing#instance.569d9054e725a069b00d4e2aa3ade22c_3" -> "dealloc#Boxing#instance.569d9054e725a069b00d4e2aa3ade22c_2" ;
 "getBool#Boxing#instance.3315ec58788820860ec4adc889dd7197_1" [label="1: Start Boxing.getBool\nFormals:  self:Boxing*\nLocals:  n:NSNumber* \n  " color=yellow style=filled]
 
 

infer/tests/codetoanalyze/objc/frontend/conditional_operation/ConditionalOperation.m.dot

@@ -1,5 +1,16 @@
 /* @generated */
 digraph cfg {
+"dealloc#A#instance.55ac864e91dcd5d484e8ab7d8eb94fcb_1" [label="1: Start A.dealloc\nFormals:  self:A*\nLocals:  \n  " color=yellow style=filled]
+
+
+	 "dealloc#A#instance.55ac864e91dcd5d484e8ab7d8eb94fcb_1" -> "dealloc#A#instance.55ac864e91dcd5d484e8ab7d8eb94fcb_3" ;
+"dealloc#A#instance.55ac864e91dcd5d484e8ab7d8eb94fcb_2" [label="2: Exit A.dealloc \n  " color=yellow style=filled]
+
+
+"dealloc#A#instance.55ac864e91dcd5d484e8ab7d8eb94fcb_3" [label="3:  Call dealloc \n  " shape="box"]
+
+
+	 "dealloc#A#instance.55ac864e91dcd5d484e8ab7d8eb94fcb_3" -> "dealloc#A#instance.55ac864e91dcd5d484e8ab7d8eb94fcb_2" ;
 "test4:#A#instance.718a300d6fa63609a70f22221a548ee5_1" [label="1: Start A.test4:\nFormals:  self:A* x:int\nLocals:  \n  " color=yellow style=filled]
 
 

infer/tests/codetoanalyze/objc/frontend/exceptions/ExceptionExample.m.dot

@@ -1,5 +1,16 @@
 /* @generated */
 digraph cfg {
+"dealloc#ExceptionExample#instance.d3f98dfd383bac562b4173d739efcd78_1" [label="1: Start ExceptionExample.dealloc\nFormals:  self:ExceptionExample*\nLocals:  \n  " color=yellow style=filled]
+
+
+	 "dealloc#ExceptionExample#instance.d3f98dfd383bac562b4173d739efcd78_1" -> "dealloc#ExceptionExample#instance.d3f98dfd383bac562b4173d739efcd78_3" ;
+"dealloc#ExceptionExample#instance.d3f98dfd383bac562b4173d739efcd78_2" [label="2: Exit ExceptionExample.dealloc \n  " color=yellow style=filled]
+
+
+"dealloc#ExceptionExample#instance.d3f98dfd383bac562b4173d739efcd78_3" [label="3:  Call dealloc \n  " shape="box"]
+
+
+	 "dealloc#ExceptionExample#instance.d3f98dfd383bac562b4173d739efcd78_3" -> "dealloc#ExceptionExample#instance.d3f98dfd383bac562b4173d739efcd78_2" ;
 "test#ExceptionExample#instance.513cde8d794322493646dbd1821516dd_1" [label="1: Start ExceptionExample.test\nFormals:  self:ExceptionExample*\nLocals:  s:NSString* \n  " color=yellow style=filled]