[inferbo] Add model for NSFastEnumeration

Reviewed By: ngorogiannis

Differential Revision: D24562644

fbshipit-source-id: 71e589883

infer/src/bufferoverrun/bufferOverrunModels.ml

@@ -1702,6 +1702,8 @@ module Call = struct
         $--> NSCollection.copy
       ; +is_objc_collection &:: "count" <>$ capt_exp $!--> NSCollection.size
       ; +is_objc_collection &:: "objectEnumerator" <>$ capt_exp $--> NSCollection.iterator
+      ; +PatternMatch.ObjectiveC.conforms_to ~protocol:"NSFastEnumeration"
+        &:: "objectEnumerator" <>$ capt_exp $--> NSCollection.iterator
       ; +PatternMatch.ObjectiveC.implements "NSArray"
         &:: "objectAtIndexedSubscript:" <>$ capt_var_exn $+ capt_exp $!--> NSCollection.get_at_index
       ; +PatternMatch.ObjectiveC.implements "NSArray"

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

@@ -0,0 +1,25 @@
+/*
+ * 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.
+ */
+#import <Foundation/Foundation.h>
+@interface MyEnumerator : NSObject<NSFastEnumeration>
+@end
+
+void loop_enumerator_linear(MyEnumerator* enumeration) {
+  for (id obj in enumeration) {
+  }
+}
+
+void call_loop_enumerator_constant() {
+  NSArray* arr = @[ @1, @2, @3 ];
+  loop_enumerator_linear(arr);
+}
+
+// We get Top because front-end can't recognize NSFastEnumeration
+void loop_id_enumerator_linear_FP(id<NSFastEnumeration> enumeration) {
+  for (id obj in enumeration) {
+  }
+}

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

@@ -44,6 +44,9 @@ codetoanalyze/objc/performance/NSDictionary.m, nsdictionary_find_key_constant, 1
 codetoanalyze/objc/performance/NSDictionary.m, nsdictionary_init_dictionary_constant, 3,  OnUIThread:false, []
 codetoanalyze/objc/performance/NSDictionary.m, nsdictionary_init_literal_constant, 45,  OnUIThread:false, []
 codetoanalyze/objc/performance/NSDictionary.m, nsdictionary_init_with_dictionary_linear, 7 + 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/NSEnumeration.m, call_loop_enumerator_constant, 35,  OnUIThread:false, []
+codetoanalyze/objc/performance/NSEnumeration.m, loop_enumerator_linear, 5 + 5 ⋅ (enumeration->elements.length.ub + 1),  OnUIThread:false, [{enumeration->elements.length.ub + 1},Loop]
+codetoanalyze/objc/performance/NSEnumeration.m, loop_id_enumerator_linear_FP, ⊤,  OnUIThread:false, [Unbounded loop,Loop]
 codetoanalyze/objc/performance/NSFileManager.m, contents_of_directory_at_url_constant, 11,  OnUIThread:false, []
 codetoanalyze/objc/performance/NSInteger.m, nsinteger_value_linear, 3 + 3 ⋅ integer + 2 ⋅ (1+max(0, integer)),  OnUIThread:false, [{1+max(0, integer)},Loop,{integer},Loop]
 codetoanalyze/objc/performance/NSInteger.m, nsnumber_number_with_int_integer_value_constant, 34,  OnUIThread:false, []

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

@@ -3,6 +3,7 @@ codetoanalyze/objc/performance/NSArray.m, nsarray_enumerator_linear, 7, INTEGER_
 codetoanalyze/objc/performance/NSArray.m, nsarray_init_constant, 3, CONDITION_ALWAYS_FALSE, no_bucket, WARNING, [Here]
 codetoanalyze/objc/performance/NSArray.m, nsarray_iterate_linear, 3, INTEGER_OVERFLOW_L5, no_bucket, ERROR, [<LHS trace>,Assignment,<RHS trace>,Assignment,Binary operation: ([0, +oo] + [1, array->elements.length.ub + 1]):signed64]
 codetoanalyze/objc/performance/NSDictionary.m, nsdictionary_enumerate_constant, 6, BUFFER_OVERRUN_L2, no_bucket, ERROR, [<Offset trace>,Assignment,<Length trace>,Array declaration,Array access: Offset: [1, 3] Size: 2]
+codetoanalyze/objc/performance/NSEnumeration.m, loop_id_enumerator_linear_FP, 0, INFINITE_EXECUTION_TIME, no_bucket, ERROR, [Unbounded loop,Loop]
 codetoanalyze/objc/performance/NSFileManager.m, contents_of_directory_at_url_constant, 7, CONDITION_ALWAYS_FALSE, no_bucket, WARNING, [Here]
 codetoanalyze/objc/performance/NSMutableArray.m, nsarray_new_constant, 2, CONDITION_ALWAYS_FALSE, no_bucket, WARNING, [Here]
 codetoanalyze/objc/performance/NSMutableArray.m, nsmarray_remove_constant, 6, BUFFER_OVERRUN_L1, no_bucket, ERROR, [<Length trace>,Array declaration,Through,Through,Through,Through,Array access: Offset: 0 Size: 0]