[cost] Fix cost models that accept blocks to take captured vars into account

Summary:
Function calls that accept blocks as arguments may have additional arguments for the captured variables of the block. Cost models for these functions only considered the case where the block arguments didn't capture variables. This diff extends the model so that we handle captured variable case.

This fixes some FNs in the analysis.

Reviewed By: skcho

Differential Revision: D28183071

fbshipit-source-id: 6a045e80e

infer/src/cost/costModels.ml

@@ -10,6 +10,7 @@ module BasicCost = CostDomain.BasicCost
 module BasicCostWithReason = CostDomain.BasicCostWithReason
 open BufferOverrunUtils.ModelEnv
 open CostUtils.CostModelEnv
+open ProcnameDispatcher.Call.FuncArg
 
 let unit_cost_model _model_env ~ret:_ _inferbo_mem = BasicCost.one ()
 
@@ -173,25 +174,29 @@ module NSCollection = struct
     cost_op (get_length coll1) (get_length coll2)
 
 
-  let enumerate_using_block array ({get_summary; model_env} as cost_model_env) ~ret inferbo_mem =
+  let enumerate_using_block args ({get_summary; model_env} as cost_model_env) ~ret inferbo_mem =
     let pname = model_env.pname in
-    match pname with
+    match List.rev args with
-    | WithBlockParameters (_, [block_name]) -> (
+    | _block :: {exp= array} :: _captured_args -> (
-      match get_summary (Procname.Block block_name) with
+        let length =
-      | Some {CostDomain.post= callee_summary} ->
+          BoundsOfNSCollection.linear_length
-          let {BasicCostWithReason.cost= callee_cost} =
+            ~of_function:(Procname.to_simplified_string pname)
-            CostDomain.get_cost_kind OperationCost callee_summary
+            array cost_model_env ~ret inferbo_mem
-          in
+        in
-          let length =
+        match pname with
-            BoundsOfNSCollection.linear_length
+        | WithBlockParameters (_, [block_name]) -> (
-              ~of_function:(Procname.to_simplified_string pname)
+          match get_summary (Procname.Block block_name) with
-              array cost_model_env ~ret inferbo_mem
+          | Some {CostDomain.post= callee_summary} ->
-          in
+              let {BasicCostWithReason.cost= callee_cost} =
-          BasicCost.mult_loop ~iter:length ~body:callee_cost
+                CostDomain.get_cost_kind OperationCost callee_summary
-      | None ->
+              in
-          BasicCost.zero )
+              BasicCost.mult_loop ~iter:length ~body:callee_cost
+          | None ->
+              length )
+        | _ ->
+            length )
     | _ ->
-        BasicCost.zero
+        BasicCost.one ()
 end
 
 module ImmutableSet = struct
@@ -278,8 +283,7 @@ module Call = struct
           &:: "addObjectsFromArray:" <>$ any_arg $+ capt_exp
           $--> BoundsOfNSCollection.linear_length ~of_function:"NSArray.addObjectsFromArray:"
         ; +PatternMatch.ObjectiveC.implements_collection
-          &:: "enumerateObjectsUsingBlock:" <>$ capt_exp $+ any_arg
+          &:: "enumerateObjectsUsingBlock:" &::.*++> NSCollection.enumerate_using_block
-          $--> NSCollection.enumerate_using_block
         ; +PatternMatch.Java.implements_collections
           &:: "sort" $ capt_exp
           $+...$--> BoundsOfCollection.n_log_n_length ~of_function:"Collections.sort"

infer/tests/codetoanalyze/objc/performance/NSArray.m

@@ -230,7 +230,7 @@ void loop_with_my_enumerator_next_object_linear_FP(MyEnumerator* enumerator) {
 
 void enumerate_via_block_linear(NSArray* array) {
   [array enumerateObjectsUsingBlock:^(id obj, NSUInteger index, BOOL* stop){
-      // do something with obj
+    NSLog(@"index: %@", index);
   }];
 }
 
@@ -239,15 +239,14 @@ void enumerate_via_block_linear(NSArray* array) {
 
 @implementation MyBlock
 
-+ (void)call_enumerate_via_block_param_linear_FN:(NSArray*)x:(int)size {
++ (void)call_enumerate_via_block_param_quadratic:(NSArray*)x:(int)size {
   void (^b)(id, NSUInteger, BOOL*) =
       ^(id object, NSUInteger indexPath, BOOL* stop) {
         for (int i = 0; i < size; i++) {
         }
       };
   // Here, captured arg size is passed as the first argument to the block,
-  // not the array x. Hence, currently we don't recognize the mode which expects
+  // not the array x.
-  // only two args.
   [x enumerateObjectsUsingBlock:b];
 }
 

infer/tests/codetoanalyze/objc/performance/cost-issues.exp

@@ -1,13 +1,13 @@
-${XCODE_ISYSROOT}/System/Library/Frameworks/Foundation.framework/Headers/NSArray.h, NSArray.enumerateObjectsUsingBlock:[objc_blockMyBlock.call_enumerate_via_block_param_linear_FN::_3], 0,  OnUIThread:false, []
+${XCODE_ISYSROOT}/System/Library/Frameworks/Foundation.framework/Headers/NSArray.h, NSArray.enumerateObjectsUsingBlock:[objc_blockMyBlock.call_enumerate_via_block_param_quadratic::_3], 0,  OnUIThread:false, []
 ${XCODE_ISYSROOT}/System/Library/Frameworks/Foundation.framework/Headers/NSArray.h, NSArray.enumerateObjectsUsingBlock:[objc_blockenumerate_via_block_linear_2], 0,  OnUIThread:false, []
 ${XCODE_ISYSROOT}/System/Library/Frameworks/Foundation.framework/Headers/NSArray.h, NSArray.indexOfObject:inSortedRange:options:usingComparator:[objc_blocknsarray_binary_search_log_FN_1], 0,  OnUIThread:false, []
 codetoanalyze/objc/performance/MyEnumerator.m, MyEnumerator.dealloc, 0,  OnUIThread:false, []
 codetoanalyze/objc/performance/MyEnumerator.m, MyEnumerator.nextObject, 5 + 3 ⋅ self->n.ub + 3 ⋅ (1+max(0, self->n.ub)),  OnUIThread:false, [{1+max(0, self->n.ub)},Loop,{self->n.ub},Loop]
-codetoanalyze/objc/performance/NSArray.m, MyBlock.call_enumerate_via_block_param_linear_FN::, 5,  OnUIThread:false, []
+codetoanalyze/objc/performance/NSArray.m, MyBlock.call_enumerate_via_block_param_quadratic::, 4 + 3 ⋅ size × x->elements.length.ub + 2 ⋅ x->elements.length.ub + 2 ⋅ x->elements.length.ub × (1+max(0, size)),  OnUIThread:false, [{1+max(0, size)},Loop,{x->elements.length.ub},Modeled call to enumerateObjectsUsingBlock:,{x->elements.length.ub},Modeled call to enumerateObjectsUsingBlock:,{size},Loop]
 codetoanalyze/objc/performance/NSArray.m, MyBlock.dealloc, 0,  OnUIThread:false, []
 codetoanalyze/objc/performance/NSArray.m, call_my_enumerator_next_object_linear, 7 + 3 ⋅ enumerator->n.ub + 3 ⋅ (1+max(0, enumerator->n.ub)),  OnUIThread:false, [{1+max(0, enumerator->n.ub)},Call to MyEnumerator.nextObject,Loop,{enumerator->n.ub},Call to MyEnumerator.nextObject,Loop]
 codetoanalyze/objc/performance/NSArray.m, call_nsarray_enumerator_param_linear, 5,  OnUIThread:false, []
-codetoanalyze/objc/performance/NSArray.m, enumerate_via_block_linear, 1,  OnUIThread:false, []
+codetoanalyze/objc/performance/NSArray.m, enumerate_via_block_linear, 1 + 11 ⋅ array->elements.length.ub,  OnUIThread:false, [{array->elements.length.ub},Modeled call to enumerateObjectsUsingBlock:]
 codetoanalyze/objc/performance/NSArray.m, loop_with_my_enumerator_next_object_linear_FP, 1 + 3 ⋅ enumerator->n.ub × (enumerator.length + 1) + 9 ⋅ (enumerator.length + 1) + 3 ⋅ (enumerator.length + 1) × (1+max(0, enumerator->n.ub)),  OnUIThread:false, [{1+max(0, enumerator->n.ub)},Call to MyEnumerator.nextObject,Loop,{enumerator.length + 1},Loop,{enumerator.length + 1},Loop,{enumerator->n.ub},Call to MyEnumerator.nextObject,Loop]
 codetoanalyze/objc/performance/NSArray.m, multiple_nsarray_enumerators_param_linear, 9 + 5 ⋅ (enumerator2.length + enumerator1.length + 2),  OnUIThread:false, [{enumerator2.length + enumerator1.length + 2},Loop]
 codetoanalyze/objc/performance/NSArray.m, nsarray_access_constant, 49,  OnUIThread:false, []
@@ -38,8 +38,8 @@ codetoanalyze/objc/performance/NSArray.m, nsarray_next_object_linear, 4 + 5 ⋅
 codetoanalyze/objc/performance/NSArray.m, nsarray_object_at_indexed_constant, 33,  OnUIThread:false, []
 codetoanalyze/objc/performance/NSArray.m, nsarray_sort_using_descriptors_constant, 38,  OnUIThread:false, []
 codetoanalyze/objc/performance/NSArray.m, nsarray_sort_using_descriptors_nlogn, 8 + array->elements.length.ub × log(array->elements.length.ub),  OnUIThread:false, [{array->elements.length.ub},Modeled call to NSArray.sortedArrayUsingDescriptors:,{array->elements.length.ub},Modeled call to NSArray.sortedArrayUsingDescriptors:]
-codetoanalyze/objc/performance/NSArray.m, objc_blockMyBlock.call_enumerate_via_block_param_linear_FN::_3, 2 + 3 ⋅ size + 2 ⋅ (1+max(0, size)),  OnUIThread:false, [{1+max(0, size)},Loop,{size},Loop]
+codetoanalyze/objc/performance/NSArray.m, objc_blockMyBlock.call_enumerate_via_block_param_quadratic::_3, 2 + 3 ⋅ size + 2 ⋅ (1+max(0, size)),  OnUIThread:false, [{1+max(0, size)},Loop,{size},Loop]
-codetoanalyze/objc/performance/NSArray.m, objc_blockenumerate_via_block_linear_2, 0,  OnUIThread:false, []
+codetoanalyze/objc/performance/NSArray.m, objc_blockenumerate_via_block_linear_2, 11,  OnUIThread:false, []
 codetoanalyze/objc/performance/NSArray.m, objc_blocknsarray_binary_search_log_FN_1, 4,  OnUIThread:false, []
 codetoanalyze/objc/performance/NSDictionary.m, nsdictionary_all_keys_linear1, 2 + 3 ⋅ dict->elements.length.ub + 4 ⋅ (dict->elements.length.ub + 1),  OnUIThread:false, [{dict->elements.length.ub + 1},Loop,{dict->elements.length.ub},Loop]
 codetoanalyze/objc/performance/NSDictionary.m, nsdictionary_all_keys_linear2, 5 + 3 ⋅ dict->elements.length.ub + 3 ⋅ (dict->elements.length.ub + 1),  OnUIThread:false, [{dict->elements.length.ub + 1},Loop,{dict->elements.length.ub},Loop]