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[cost][inferbo] Add models for indexOf

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Reviewed By: skcho

Differential Revision: D16089480

fbshipit-source-id: 1065a1830
master
Ezgi Çiçek 5 years ago committed by Facebook Github Bot
parent c8d1da1e0d
commit 0682ccc1e9
4 changed files with 107 additions and 3 deletions
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15
infer/src/bufferoverrun/bufferOverrunModels.ml
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@ -357,6 +357,20 @@ let inferbo_set_size src_exp size_exp =
let model_by_value value id mem = Dom.Mem.add_stack (Loc.of_id id) value mem
(** Given a string of length n, return itv [-1, n_u-1]. *)
let range_itv_mone exp mem =
eval_string_len exp mem |> BufferOverrunDomain.Val.get_itv |> Itv.set_lb_zero |> Itv.decr
let indexOf exp =
let exec _ ~ret:(ret_id, _) mem =
(* if not found, indexOf returns -1. *)
let v = range_itv_mone exp mem |> Dom.Val.of_itv in
model_by_value v ret_id mem
in
{exec; check= no_check}
let cast exp =
let exec {integer_type_widths} ~ret:(ret_id, _) mem =
let itv = Sem.eval integer_type_widths exp mem in
@ -877,6 +891,7 @@ module Call = struct
; -"strcat" <>$ capt_exp $+ capt_exp $+...$--> strcat
; +PatternMatch.implements_lang "String"
&:: "concat" <>$ capt_exp $+ capt_exp $+...$--> strcat
; +PatternMatch.implements_lang "String" &:: "indexOf" <>$ capt_exp $+ any_arg $--> indexOf
; -"strcpy" <>$ capt_exp $+ capt_exp $+...$--> strcpy
; -"strncpy" <>$ capt_exp $+ capt_exp $+ capt_exp $+...$--> strncpy
; -"snprintf" <>--> snprintf

59
infer/src/checkers/costModels.ml
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@ -50,6 +50,19 @@ let modeled ~of_function {pname; location} ~ret:(_, ret_typ) _ : BasicCost.t =
of_itv ~itv ~degree_kind:Polynomials.DegreeKind.Linear ~of_function location
(** Given a string of length n and an optional starting index i (0 by
default), return itv [0, n_u-i_l] *)
let string_len_range_itv exp ~from mem =
let itv = BufferOverrunModels.eval_string_len exp mem |> BufferOverrunDomain.Val.get_itv in
Option.value_map from ~default:itv ~f:(fun (start_exp, integer_type_widths) ->
let start_itv =
BufferOverrunSemantics.eval integer_type_widths start_exp mem
|> BufferOverrunDomain.Val.get_itv
in
Itv.minus itv start_itv )
|> Itv.set_lb_zero
module BoundsOf (Container : S) = struct
let of_length exp {location} ~ret:_ mem ~of_function ~degree_kind =
let itv = Container.length exp mem |> BufferOverrunDomain.Val.get_itv in
@ -66,7 +79,7 @@ module BoundsOf (Container : S) = struct
BasicCost.mult n log_n
end
module String = struct
module JavaString = struct
let substring_aux ~begin_idx ~end_v {integer_type_widths; location} inferbo_mem =
let begin_v = BufferOverrunSemantics.eval integer_type_widths begin_idx inferbo_mem in
let itv =
@ -85,6 +98,36 @@ module String = struct
substring_aux ~begin_idx
~end_v:(BufferOverrunSemantics.eval integer_type_widths end_idx inferbo_mem)
model_env inferbo_mem
(** O(|m|) where m is the given string and |.| is the length function *)
let indexOf_char exp {location} ~ret:_ inferbo_mem =
let itv = string_len_range_itv exp ~from:None inferbo_mem in
of_itv ~itv ~degree_kind:Polynomials.DegreeKind.Linear ~of_function:"String.indexOf" location
(** O(|m|-|n|) where m is the given string and n is the index to start searching from *)
let indexOf_char_starting_from exp start_exp {integer_type_widths; location} ~ret:_ inferbo_mem =
let itv = string_len_range_itv exp ~from:(Some (start_exp, integer_type_widths)) inferbo_mem in
of_itv ~itv ~degree_kind:Polynomials.DegreeKind.Linear ~of_function:"String.indexOf" location
(** O(|m|.|n|) where m and n are the given strings *)
let indexOf_str exp index_exp {location} ~ret:_ inferbo_mem =
let itv =
BufferOverrunModels.eval_string_len exp inferbo_mem |> BufferOverrunDomain.Val.get_itv
in
let index_itv =
BufferOverrunModels.eval_string_len index_exp inferbo_mem |> BufferOverrunDomain.Val.get_itv
in
let n =
of_itv ~itv ~degree_kind:Polynomials.DegreeKind.Linear ~of_function:"String.indexOf" location
in
let m =
of_itv ~itv:index_itv ~degree_kind:Polynomials.DegreeKind.Linear
~of_function:"String.indexOf" location
in
BasicCost.mult n m
end
module BoundsOfCollection = BoundsOf (Collection)
@ -93,6 +136,7 @@ module BoundsOfArray = BoundsOf (Array)
module Call = struct
let dispatch : (Tenv.t, model) ProcnameDispatcher.Call.dispatcher =
let open ProcnameDispatcher.Call in
let int_typ = Typ.mk (Typ.Tint Typ.IInt) in
make_dispatcher
[ +PatternMatch.implements_collections
&:: "sort" $ capt_exp
@ -131,11 +175,20 @@ module Call = struct
&:: "shuffle" <>$ capt_exp
$+...$--> BoundsOfCollection.linear_length ~of_function:"Collections.shuffle"
; +PatternMatch.implements_lang "String"
&:: "substring" <>$ capt_exp $+ capt_exp $--> String.substring
&:: "substring" <>$ capt_exp $+ capt_exp $--> JavaString.substring
; +PatternMatch.implements_lang "String"
&:: "indexOf" <>$ capt_exp
$+ capt_exp_of_typ (+PatternMatch.implements_lang "String")
$--> JavaString.indexOf_str
; +PatternMatch.implements_lang "String"
&:: "indexOf" <>$ capt_exp $+ any_arg_of_prim_typ int_typ $+ capt_exp
$--> JavaString.indexOf_char_starting_from
; +PatternMatch.implements_lang "String"
&:: "indexOf" <>$ capt_exp $+ any_arg_of_prim_typ int_typ $--> JavaString.indexOf_char
; +PatternMatch.implements_lang "String"
&:: "substring"
$ any_arg_of_typ (+PatternMatch.implements_lang "String")
$+ capt_exp $+ capt_exp $--> String.substring_no_end
$+ capt_exp $+ capt_exp $--> JavaString.substring_no_end
; +PatternMatch.implements_inject "Provider"
&:: "get"
<>--> modeled ~of_function:"Provider.get" ]

32
infer/tests/codetoanalyze/java/performance/StringTest.java
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@ -0,0 +1,32 @@
/*
* 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.
*/
class StringTest {
String mId;
int indexof_linear(String m) {
return m.indexOf('_');
}
int indexof_from_linear(String m, int j) {
return m.indexOf('_', j);
}
int indexof_quadratic(String m, String n) {
return m.indexOf(n);
}
int indexof_constant(String n) {
String m = "hi";
return m.indexOf('i');
}
public String index_substring_linear() {
int index = indexof_linear(mId);
return mId.substring(0, index);
}
}

4
infer/tests/codetoanalyze/java/performance/issues.exp
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@ -156,6 +156,10 @@ codetoanalyze/java/performance/MapTest.java, MapTest.entrySet_linear(java.util.M
codetoanalyze/java/performance/MapTest.java, MapTest.keySet_linear(java.util.Map):void, 1, EXPENSIVE_EXECUTION_TIME, no_bucket, ERROR, [with estimated cost 7 + 8 ⋅ (map.length - 1) + 3 ⋅ map.length, degree = 1,{map.length},Loop at line 13,{map.length - 1},Loop at line 13]
codetoanalyze/java/performance/MapTest.java, MapTest.putAll_linear(java.util.Map):void, 3, EXPENSIVE_EXECUTION_TIME, no_bucket, ERROR, [with estimated cost 13 + 8 ⋅ (map.length - 1) + 3 ⋅ map.length, degree = 1,{map.length},Loop at line 28,{map.length - 1},Loop at line 28]
codetoanalyze/java/performance/MapTest.java, MapTest.values_linear(java.util.Map):void, 2, EXPENSIVE_EXECUTION_TIME, no_bucket, ERROR, [with estimated cost 13 + 8 ⋅ map.length + 3 ⋅ (map.length + 1), degree = 1,{map.length + 1},Loop at line 22,{map.length},Loop at line 22]
codetoanalyze/java/performance/StringTest.java, StringTest.index_substring_linear():java.lang.String, 1, EXPENSIVE_EXECUTION_TIME, no_bucket, ERROR, [with estimated cost 9 + this.mId.length, degree = 1,{this.mId.length},call to int StringTest.indexof_linear(String),Modeled call to String.indexOf]
codetoanalyze/java/performance/StringTest.java, StringTest.indexof_from_linear(java.lang.String,int):int, 1, EXPENSIVE_EXECUTION_TIME, no_bucket, ERROR, [with estimated cost 3 + (-j + m.length), degree = 1,{-j + m.length},Modeled call to String.indexOf]
codetoanalyze/java/performance/StringTest.java, StringTest.indexof_linear(java.lang.String):int, 1, EXPENSIVE_EXECUTION_TIME, no_bucket, ERROR, [with estimated cost 2 + m.length, degree = 1,{m.length},Modeled call to String.indexOf]
codetoanalyze/java/performance/StringTest.java, StringTest.indexof_quadratic(java.lang.String,java.lang.String):int, 1, EXPENSIVE_EXECUTION_TIME, no_bucket, ERROR, [with estimated cost 3 + m.length × n.length, degree = 2,{n.length},Modeled call to String.indexOf,{m.length},Modeled call to String.indexOf]
codetoanalyze/java/performance/Switch.java, codetoanalyze.java.performance.Switch.test_switch():int, 3, CONDITION_ALWAYS_TRUE, no_bucket, WARNING, [Here]
codetoanalyze/java/performance/Switch.java, codetoanalyze.java.performance.Switch.test_switch():int, 3, EXPENSIVE_EXECUTION_TIME, no_bucket, ERROR, [with estimated cost 798, degree = 0]
codetoanalyze/java/performance/Switch.java, codetoanalyze.java.performance.Switch.vanilla_switch(int):void, 2, CONDITION_ALWAYS_TRUE, no_bucket, WARNING, [Here]

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