From c3909c0434522ebc9141e06a8f23ec71d121cc7e Mon Sep 17 00:00:00 2001
From: Qianyi Shu <qianyishu@fb.com>
Date: Thu, 3 Sep 2020 05:09:42 -0700
Subject: [PATCH] [cost] add iterator model for NSOrderedSet

Summary:
As title.

Facebook
Found this case by examining db.

>
D23394545
Time complexity of `_registerTabPreloadables` has **decreased** from `Top` to `O(1)`. Please make sure this is an expected change. You can inspect the trace to understand the complexity increase:

Reviewed By: ezgicicek

Differential Revision: D23448099

fbshipit-source-id: 108fd1ef2
---
 infer/src/bufferoverrun/bufferOverrunModels.ml       |  4 ++++
 .../codetoanalyze/objc/performance/NSOrderedSet.m    | 12 ++++++++++++
 .../codetoanalyze/objc/performance/cost-issues.exp   |  1 +
 3 files changed, 17 insertions(+)
 create mode 100644 infer/tests/codetoanalyze/objc/performance/NSOrderedSet.m

diff --git a/infer/src/bufferoverrun/bufferOverrunModels.ml b/infer/src/bufferoverrun/bufferOverrunModels.ml
index ab43652b3..def0e9f1a 100644
--- a/infer/src/bufferoverrun/bufferOverrunModels.ml
+++ b/infer/src/bufferoverrun/bufferOverrunModels.ml
@@ -1734,6 +1734,10 @@ module Call = struct
         &:: "objectEnumerator" <>$ capt_exp $--> NSCollection.iterator
       ; +PatternMatch.ObjectiveC.implements "NSDictionary"
         &:: "keyEnumerator" <>$ capt_exp $--> NSCollection.iterator
+      ; +PatternMatch.ObjectiveC.implements "NSOrderedSet"
+        &:: "objectEnumerator" <>$ capt_exp $--> NSCollection.iterator
+      ; +PatternMatch.ObjectiveC.implements "NSOrderedSet"
+        &:: "reverseObjectEnumerator" <>$ capt_exp $--> NSCollection.iterator
       ; +PatternMatch.ObjectiveC.implements "NSNumber" &:: "numberWithInt:" <>$ capt_exp $--> id
       ; +PatternMatch.ObjectiveC.implements "NSNumber" &:: "integerValue" <>$ capt_exp $--> id
       ; +PatternMatch.ObjectiveC.implements "NSString"
diff --git a/infer/tests/codetoanalyze/objc/performance/NSOrderedSet.m b/infer/tests/codetoanalyze/objc/performance/NSOrderedSet.m
new file mode 100644
index 000000000..8852eaeda
--- /dev/null
+++ b/infer/tests/codetoanalyze/objc/performance/NSOrderedSet.m
@@ -0,0 +1,12 @@
+/*
+ * 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>
+
+void nsordered_set_iterate_linear(NSOrderedSet* ordered_set) {
+  for (id item in ordered_set) {
+  }
+}
diff --git a/infer/tests/codetoanalyze/objc/performance/cost-issues.exp b/infer/tests/codetoanalyze/objc/performance/cost-issues.exp
index c636f55ce..93d252d44 100644
--- a/infer/tests/codetoanalyze/objc/performance/cost-issues.exp
+++ b/infer/tests/codetoanalyze/objc/performance/cost-issues.exp
@@ -54,6 +54,7 @@ codetoanalyze/objc/performance/NSMutableArray.m, nsmarray_set_linear, 3 + 11 ⋅
 codetoanalyze/objc/performance/NSMutableDictionary.m, nsmutabledictionary_set_element_in_loop_linear, 5 + 5 ⋅ 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/NSMutableString.m, nsmstring_append_string_constant, 14 + 3 ⋅ (str.length.ub + 5) + 3 ⋅ (str.length.ub + 6),  OnUIThread:false, [{str.length.ub + 6},Loop,{str.length.ub + 5},Loop]
 codetoanalyze/objc/performance/NSMutableString.m, nsmstring_append_string_linear, 5 + str2.length.ub + 3 ⋅ (str2.length.ub + str1.length.ub) + 3 ⋅ (str2.length.ub + str1.length.ub + 1),  OnUIThread:false, [{str2.length.ub + str1.length.ub + 1},Loop,{str2.length.ub + str1.length.ub},Loop,{str2.length.ub},Modeled call to NSMutableString.appendString:]
+codetoanalyze/objc/performance/NSOrderedSet.m, nsordered_set_iterate_linear, 5 + ordered_set->elements.length.ub + 4 ⋅ (ordered_set->elements.length.ub + 1),  OnUIThread:false, [{ordered_set->elements.length.ub + 1},Loop,{ordered_set->elements.length.ub},Loop]
 codetoanalyze/objc/performance/NSString.m, call_component_separated_by_char_constant, 46,  OnUIThread:false, []
 codetoanalyze/objc/performance/NSString.m, call_init_with_string_constant, 15,  OnUIThread:false, []
 codetoanalyze/objc/performance/NSString.m, component_seperated_by_char_linear, 6 + m.length.ub + 3 ⋅ (-1+max(2, m.length.ub)) + 3 ⋅ (max(2, m.length.ub)),  OnUIThread:false, [{max(2, m.length.ub)},Loop,{-1+max(2, m.length.ub)},Loop,{m.length.ub},Modeled call to NSString.componentsSeparatedByString:]