[objc blocks] Specialize store instructions with current closure in methods specialized with blocks as arguments

Reviewed By: mbouaziz, jvillard

Differential Revision: D7744403

fbshipit-source-id: 42ad5f8

infer/src/IR/Procdesc.ml

@@ -662,6 +662,18 @@ let specialize_with_block_args_instrs resolved_pdesc substitutions =
         exp
   in
   let convert_instr (instrs, id_map) instr =
+    let get_block_name_and_load_captured_vars_instrs block_var loc =
+      let block_name, extra_formals = Mangled.Map.find block_var substitutions in
+      let ids, id_exp_typs, load_instrs =
+        List.map extra_formals ~f:(fun (var, typ) ->
+            let id = Ident.create_fresh Ident.knormal in
+            let pvar = Pvar.mk var resolved_pname in
+            (id, (Exp.Var id, pvar, typ), Sil.Load (id, Exp.Lvar pvar, typ, loc)) )
+        |> List.unzip3
+      in
+      let remove_temps_instr = Sil.Remove_temps (ids, loc) in
+      (block_name, id_exp_typs, load_instrs, remove_temps_instr)
+    in
     let convert_generic_call return_ids exp origin_args loc call_flags =
       let converted_args = List.map ~f:(fun (exp, typ) -> (convert_exp exp, typ)) origin_args in
       let call_instr = Sil.Call (return_ids, exp, converted_args, loc, call_flags) in
@@ -675,6 +687,14 @@ let specialize_with_block_args_instrs resolved_pdesc substitutions =
         (instrs, id_map)
     | Sil.Load (id, origin_exp, origin_typ, loc) ->
         (Sil.Load (id, convert_exp origin_exp, origin_typ, loc) :: instrs, id_map)
+    | Sil.Store (assignee_exp, origin_typ, Exp.Var id, loc) when Ident.Map.mem id id_map ->
+        let block_param = Ident.Map.find id id_map in
+        let block_name, id_exp_typs, load_instrs, remove_temps_instr =
+          get_block_name_and_load_captured_vars_instrs block_param loc
+        in
+        let closure = Exp.Closure {name= block_name; captured_vars= id_exp_typs} in
+        let instr = Sil.Store (assignee_exp, origin_typ, closure, loc) in
+        (remove_temps_instr :: instr :: load_instrs @ instrs, id_map)
     | Sil.Store (assignee_exp, origin_typ, origin_exp, loc) ->
         let set_instr =
           Sil.Store (convert_exp assignee_exp, origin_typ, convert_exp origin_exp, loc)
@@ -682,23 +702,12 @@ let specialize_with_block_args_instrs resolved_pdesc substitutions =
         (set_instr :: instrs, id_map)
     | Sil.Call (return_ids, Exp.Var id, origin_args, loc, call_flags) -> (
       try
-        let block_name, extra_formals =
+        let block_name, id_exp_typs, load_instrs, remove_temps_instr =
           let block_var = Ident.Map.find id id_map in
-          Mangled.Map.find block_var substitutions
-        in
-        (* once we find the block in the map, it means that we need to subsitute it with the
-        call to the concrete block, and pass the fresh formals as arguments *)
-        let ids_typs, load_instrs =
-          let captured_ids_instrs =
-            List.map extra_formals ~f:(fun (var, typ) ->
-                let id = Ident.create_fresh Ident.knormal in
-                let pvar = Pvar.mk var resolved_pname in
-                ((id, typ), Sil.Load (id, Exp.Lvar pvar, typ, loc)) )
-          in
-          List.unzip captured_ids_instrs
+          get_block_name_and_load_captured_vars_instrs block_var loc
         in
         let call_instr =
-          let id_exps = List.map ~f:(fun (id, typ) -> (Exp.Var id, typ)) ids_typs in
+          let id_exps = List.map ~f:(fun (id, _, typ) -> (id, typ)) id_exp_typs in
           let converted_args =
             List.map ~f:(fun (exp, typ) -> (convert_exp exp, typ)) origin_args
           in
@@ -709,11 +718,7 @@ let specialize_with_block_args_instrs resolved_pdesc substitutions =
             , loc
             , call_flags )
         in
-        let remove_temps_instrs =
-          let ids = List.map ~f:(fun (id, _) -> id) ids_typs in
-          Sil.Remove_temps (ids, loc)
-        in
-        let instrs = remove_temps_instrs :: call_instr :: load_instrs @ instrs in
+        let instrs = remove_temps_instr :: call_instr :: load_instrs @ instrs in
         (instrs, id_map)
       with Caml.Not_found ->
         convert_generic_call return_ids (Exp.Var id) origin_args loc call_flags )

infer/tests/codetoanalyze/objc/errors/Makefile

@@ -95,6 +95,7 @@ SOURCES_ARC = \
   memory_leaks_benchmark/retain_cycle2.m \
 	memory_leaks_benchmark/RetainCycleBlocks.m \
 	memory_leaks_benchmark/RetainCyclePropertyInProtocol.m \
+	memory_leaks_benchmark/RetainCycleBlockAsParameter.m \
 	memory_leaks_benchmark/RetainCycleBlockCapturedVar.m \
 	memory_leaks_benchmark/RetainCycleDeduplication.m \
   npe/BoxedNumberExample.m \

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

@@ -28,6 +28,7 @@ codetoanalyze/objc/errors/field_superclass/SubtypingExample.m, subtyping_test, 0
 codetoanalyze/objc/errors/initialization/struct_initlistexpr.c, field_set_correctly, 2, DIVIDE_BY_ZERO, ERROR, [start of procedure field_set_correctly()]
 codetoanalyze/objc/errors/initialization/struct_initlistexpr.c, implicit_expr_set_correctly, 3, DIVIDE_BY_ZERO, ERROR, [start of procedure implicit_expr_set_correctly()]
 codetoanalyze/objc/errors/initialization/struct_initlistexpr.c, point_coords_set_correctly, 2, DIVIDE_BY_ZERO, ERROR, [start of procedure point_coords_set_correctly()]
+codetoanalyze/objc/errors/memory_leaks_benchmark/RetainCycleBlockAsParameter.m, FBSomeDataManager_fetchNewData, 2, RETAIN_CYCLE, ERROR, [start of procedure fetchNewData,start of procedure initWithCompletionBlock:,return from a call to Fetcher_initWithCompletionBlock:_objc_blockFBSomeDataManager_fetchNewData_1]
 codetoanalyze/objc/errors/memory_leaks_benchmark/RetainCycleBlockCapturedVar.m, LinkResolver_test_bad, 3, RETAIN_CYCLE, ERROR, [start of procedure test_bad,Executing synthesized setter setDidFinishLoad:]
 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:]

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

@@ -0,0 +1,54 @@
+/*
+ * 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>
+#import <Foundation/NSData.h>
+
+typedef void (^MyHandler)(NSData* newData);
+
+@interface Fetcher : NSObject
+
+@property(nonatomic, strong) MyHandler completionBlock;
+
+- (instancetype)initWithCompletionBlock:(MyHandler)block;
+
+@end
+
+@implementation Fetcher
+
+- (instancetype)initWithCompletionBlock:(_Nonnull MyHandler)block {
+  _completionBlock = block;
+  return self;
+}
+
+@end
+
+@interface FBSomeDataManager : NSObject
+
+- (void)setData:(NSData*)data;
+
+@end
+
+@implementation FBSomeDataManager {
+  Fetcher* _fetcher;
+  NSData* _data;
+}
+
+- (void)setData:(NSData*)data {
+  _data = data;
+}
+
+- (void)fetchNewData {
+  // We retain fetcher
+  _fetcher = [[Fetcher alloc] initWithCompletionBlock:^(NSData* newData) {
+    // fetcher retains us
+    [self setData:newData];
+  }];
+}
+
+@end