File: checkbufferoverrun.cpp

package info (click to toggle)
cppcheck 2.17.1-2
  • links: PTS, VCS
  • area: main
  • in suites: sid, trixie
  • size: 25,384 kB
  • sloc: cpp: 263,341; python: 19,737; ansic: 7,953; sh: 1,018; makefile: 996; xml: 994; cs: 291
file content (1239 lines) | stat: -rw-r--r-- 54,209 bytes parent folder | download
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
/*
 * Cppcheck - A tool for static C/C++ code analysis
 * Copyright (C) 2007-2025 Cppcheck team.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

//---------------------------------------------------------------------------
// Buffer overrun..
//---------------------------------------------------------------------------

#include "checkbufferoverrun.h"

#include "astutils.h"
#include "errorlogger.h"
#include "errortypes.h"
#include "library.h"
#include "mathlib.h"
#include "platform.h"
#include "settings.h"
#include "symboldatabase.h"
#include "token.h"
#include "tokenize.h"
#include "tokenlist.h"
#include "utils.h"
#include "valueflow.h"

#include <algorithm>
#include <cstdlib>
#include <functional>
#include <iterator>
#include <numeric> // std::accumulate
#include <sstream>
#include <utility>

#include "xml.h"

//---------------------------------------------------------------------------

// Register this check class (by creating a static instance of it)
namespace {
    CheckBufferOverrun instance;
}

//---------------------------------------------------------------------------

// CWE ids used:
static const CWE CWE131(131U);  // Incorrect Calculation of Buffer Size
static const CWE CWE170(170U);  // Improper Null Termination
static const CWE CWE_ARGUMENT_SIZE(398U);  // Indicator of Poor Code Quality
static const CWE CWE_ARRAY_INDEX_THEN_CHECK(398U);  // Indicator of Poor Code Quality
static const CWE CWE758(758U);  // Reliance on Undefined, Unspecified, or Implementation-Defined Behavior
static const CWE CWE_POINTER_ARITHMETIC_OVERFLOW(758U); // Reliance on Undefined, Unspecified, or Implementation-Defined Behavior
static const CWE CWE_BUFFER_UNDERRUN(786U);  // Access of Memory Location Before Start of Buffer
static const CWE CWE_BUFFER_OVERRUN(788U);   // Access of Memory Location After End of Buffer

//---------------------------------------------------------------------------

static const ValueFlow::Value *getBufferSizeValue(const Token *tok)
{
    const std::list<ValueFlow::Value> &tokenValues = tok->values();
    const auto it = std::find_if(tokenValues.cbegin(), tokenValues.cend(), std::mem_fn(&ValueFlow::Value::isBufferSizeValue));
    return it == tokenValues.cend() ? nullptr : &*it;
}

static int getMinFormatStringOutputLength(const std::vector<const Token*> &parameters, nonneg int formatStringArgNr)
{
    if (formatStringArgNr <= 0 || formatStringArgNr > parameters.size())
        return 0;
    if (parameters[formatStringArgNr - 1]->tokType() != Token::eString)
        return 0;
    const std::string &formatString = parameters[formatStringArgNr - 1]->str();
    bool percentCharFound = false;
    int outputStringSize = 0;
    bool handleNextParameter = false;
    std::string digits_string;
    bool i_d_x_f_found = false;
    int parameterLength = 0;
    int inputArgNr = formatStringArgNr;
    for (std::size_t i = 1; i + 1 < formatString.length(); ++i) {
        if (formatString[i] == '\\') {
            if (i < formatString.length() - 1 && formatString[i + 1] == '0')
                break;

            ++outputStringSize;
            ++i;
            continue;
        }

        if (percentCharFound) {
            switch (formatString[i]) {
            case 'f':
            case 'x':
            case 'X':
            case 'i':
                i_d_x_f_found = true;
                handleNextParameter = true;
                parameterLength = 1; // TODO
                break;
            case 'c':
            case 'e':
            case 'E':
            case 'g':
            case 'o':
            case 'u':
            case 'p':
            case 'n':
                handleNextParameter = true;
                parameterLength = 1; // TODO
                break;
            case 'd':
                i_d_x_f_found = true;
                parameterLength = 1;
                if (inputArgNr < parameters.size() && parameters[inputArgNr]->hasKnownIntValue())
                    parameterLength = MathLib::toString(parameters[inputArgNr]->getKnownIntValue()).length();

                handleNextParameter = true;
                break;
            case 's':
                parameterLength = 0;
                if (inputArgNr < parameters.size() && parameters[inputArgNr]->tokType() == Token::eString)
                    parameterLength = Token::getStrLength(parameters[inputArgNr]);

                handleNextParameter = true;
                break;
            }
        }

        if (formatString[i] == '%')
            percentCharFound = !percentCharFound;
        else if (percentCharFound) {
            digits_string.append(1, formatString[i]);
        }

        if (!percentCharFound)
            outputStringSize++;

        if (handleNextParameter) {
            // NOLINTNEXTLINE(cert-err34-c) - intentional use
            int tempDigits = std::abs(std::atoi(digits_string.c_str()));
            if (i_d_x_f_found)
                tempDigits = std::max(tempDigits, 1);

            if (digits_string.find('.') != std::string::npos) {
                const std::string endStr = digits_string.substr(digits_string.find('.') + 1);
                // NOLINTNEXTLINE(cert-err34-c) - intentional use
                const int maxLen = std::max(std::abs(std::atoi(endStr.c_str())), 1);

                if (formatString[i] == 's') {
                    // For strings, the length after the dot "%.2s" will limit
                    // the length of the string.
                    parameterLength = std::min(parameterLength, maxLen);
                } else {
                    // For integers, the length after the dot "%.2d" can
                    // increase required length
                    tempDigits = std::max(tempDigits, maxLen);
                }
            }

            if (tempDigits < parameterLength)
                outputStringSize += parameterLength;
            else
                outputStringSize += tempDigits;

            parameterLength = 0;
            digits_string.clear();
            i_d_x_f_found = false;
            percentCharFound = false;
            handleNextParameter = false;
            ++inputArgNr;
        }
    }

    return outputStringSize;
}

//---------------------------------------------------------------------------

static bool getDimensionsEtc(const Token * const arrayToken, const Settings &settings, std::vector<Dimension> &dimensions, ErrorPath &errorPath, bool &mightBeLarger, MathLib::bigint &path)
{
    const Token *array = arrayToken;
    while (Token::Match(array, ".|::"))
        array = array->astOperand2();

    if (array->variable() && array->variable()->isArray() && !array->variable()->dimensions().empty()) {
        dimensions = array->variable()->dimensions();
        if (dimensions[0].num <= 1 || !dimensions[0].tok) {
            visitAstNodes(arrayToken,
                          [&](const Token *child) {
                if (child->originalName() == "->") {
                    mightBeLarger = true;
                    return ChildrenToVisit::none;
                }
                return ChildrenToVisit::op1_and_op2;
            });
        }
    } else if (const Token *stringLiteral = array->getValueTokenMinStrSize(settings, &path)) {
        Dimension dim;
        dim.tok = nullptr;
        dim.num = Token::getStrArraySize(stringLiteral);
        dim.known = array->hasKnownValue();
        dimensions.emplace_back(dim);
    } else if (array->valueType() && array->valueType()->pointer >= 1 && (array->valueType()->isIntegral() || array->valueType()->isFloat())) {
        const ValueFlow::Value *value = getBufferSizeValue(array);
        if (!value)
            return false;
        path = value->path;
        errorPath = value->errorPath;
        Dimension dim;
        dim.known = value->isKnown();
        dim.tok = nullptr;
        const MathLib::bigint typeSize = array->valueType()->typeSize(settings.platform, array->valueType()->pointer > 1);
        if (typeSize == 0)
            return false;
        dim.num = value->intvalue / typeSize;
        dimensions.emplace_back(dim);
    }
    return !dimensions.empty();
}

static ValueFlow::Value makeSizeValue(MathLib::bigint size, MathLib::bigint path)
{
    ValueFlow::Value v(size);
    v.path = path;
    return v;
}

static std::vector<ValueFlow::Value> getOverrunIndexValues(const Token* tok,
                                                           const Token* arrayToken,
                                                           const std::vector<Dimension>& dimensions,
                                                           const std::vector<const Token*>& indexTokens,
                                                           MathLib::bigint path)
{
    const Token *array = arrayToken;
    while (Token::Match(array, ".|::"))
        array = array->astOperand2();

    bool isArrayIndex = tok->str() == "[";
    if (isArrayIndex) {
        const Token* parent = tok;
        while (Token::simpleMatch(parent, "["))
            parent = parent->astParent();
        if (!parent || parent->isUnaryOp("&"))
            isArrayIndex = false;
    }

    bool overflow = false;
    std::vector<ValueFlow::Value> indexValues;
    for (std::size_t i = 0; i < dimensions.size() && i < indexTokens.size(); ++i) {
        MathLib::bigint size = dimensions[i].num;
        if (!isArrayIndex)
            size++;
        const bool zeroArray = array->variable() && array->variable()->isArray() && dimensions[i].num == 0;
        std::vector<ValueFlow::Value> values = !zeroArray
                                                   ? ValueFlow::isOutOfBounds(makeSizeValue(size, path), indexTokens[i])
                                                   : std::vector<ValueFlow::Value>{};
        if (values.empty()) {
            if (indexTokens[i]->hasKnownIntValue())
                indexValues.push_back(indexTokens[i]->values().front());
            else
                indexValues.push_back(ValueFlow::Value::unknown());
            continue;
        }
        overflow = true;
        indexValues.push_back(values.front());
    }
    if (overflow)
        return indexValues;
    return {};
}

void CheckBufferOverrun::arrayIndex()
{
    logChecker("CheckBufferOverrun::arrayIndex");

    for (const Token *tok = mTokenizer->tokens(); tok; tok = tok->next()) {
        if (tok->str() != "[")
            continue;
        const Token *array = tok->astOperand1();
        while (Token::Match(array, ".|::"))
            array = array->astOperand2();
        if (!array || ((!array->variable() || array->variable()->nameToken() == array) && array->tokType() != Token::eString))
            continue;
        if (!array->scope()->isExecutable()) {
            // LHS in non-executable scope => This is just a definition
            const Token *parent = tok;
            while (parent && !Token::simpleMatch(parent->astParent(), "="))
                parent = parent->astParent();
            if (!parent || parent == parent->astParent()->astOperand1())
                continue;
        }

        if (astIsContainer(array))
            continue;

        std::vector<const Token *> indexTokens;
        for (const Token *tok2 = tok; tok2 && tok2->str() == "["; tok2 = tok2->link()->next()) {
            if (!tok2->astOperand2()) {
                indexTokens.clear();
                break;
            }
            indexTokens.emplace_back(tok2->astOperand2());
        }
        if (indexTokens.empty())
            continue;

        std::vector<Dimension> dimensions;
        ErrorPath errorPath;
        bool mightBeLarger = false;
        MathLib::bigint path = 0;
        if (!getDimensionsEtc(tok->astOperand1(), *mSettings, dimensions, errorPath, mightBeLarger, path))
            continue;

        const Variable* const var = array->variable();
        if (var && var->isArgument() && var->scope()) {
            const Token* changeTok = var->scope()->bodyStart;
            bool isChanged = false;
            while ((changeTok = findVariableChanged(changeTok->next(), var->scope()->bodyEnd, /*indirect*/ 0, var->declarationId(),
                                                    /*globalvar*/ false, *mSettings))) {
                if (!Token::simpleMatch(changeTok->astParent(), "[")) {
                    isChanged = true;
                    break;
                }
            }
            if (isChanged)
                continue;
        }

        // Positive index
        if (!mightBeLarger) { // TODO check arrays with dim 1 also
            const std::vector<ValueFlow::Value>& indexValues =
                getOverrunIndexValues(tok, tok->astOperand1(), dimensions, indexTokens, path);
            if (!indexValues.empty())
                arrayIndexError(tok, dimensions, indexValues);
        }

        // Negative index
        bool neg = false;
        std::vector<ValueFlow::Value> negativeIndexes;
        for (const Token * indexToken : indexTokens) {
            const ValueFlow::Value *negativeValue = indexToken->getValueLE(-1, *mSettings);
            if (negativeValue) {
                negativeIndexes.emplace_back(*negativeValue);
                neg = true;
            } else {
                negativeIndexes.emplace_back(ValueFlow::Value::unknown());
            }
        }
        if (neg) {
            negativeIndexError(tok, dimensions, negativeIndexes);
        }
    }
}

static std::string stringifyIndexes(const std::string& array, const std::vector<ValueFlow::Value>& indexValues)
{
    if (indexValues.size() == 1)
        return MathLib::toString(indexValues[0].intvalue);

    std::ostringstream ret;
    ret << array;
    for (const ValueFlow::Value& index : indexValues) {
        ret << "[";
        if (index.isNonValue())
            ret << "*";
        else
            ret << index.intvalue;
        ret << "]";
    }
    return ret.str();
}

static std::string arrayIndexMessage(const Token* tok,
                                     const std::vector<Dimension>& dimensions,
                                     const std::vector<ValueFlow::Value>& indexValues,
                                     const Token* condition)
{
    auto add_dim = [](const std::string &s, const Dimension &dim) {
        return s + "[" + MathLib::toString(dim.num) + "]";
    };
    const std::string array = std::accumulate(dimensions.cbegin(), dimensions.cend(), tok->astOperand1()->expressionString(), std::move(add_dim));

    std::ostringstream errmsg;
    if (condition)
        errmsg << ValueFlow::eitherTheConditionIsRedundant(condition)
               << " or the array '" << array << "' is accessed at index " << stringifyIndexes(tok->astOperand1()->expressionString(), indexValues) << ", which is out of bounds.";
    else
        errmsg << "Array '" << array << "' accessed at index " << stringifyIndexes(tok->astOperand1()->expressionString(), indexValues) <<  ", which is out of bounds.";

    return errmsg.str();
}

void CheckBufferOverrun::arrayIndexError(const Token* tok,
                                         const std::vector<Dimension>& dimensions,
                                         const std::vector<ValueFlow::Value>& indexes)
{
    if (!tok) {
        reportError(tok, Severity::error, "arrayIndexOutOfBounds", "Array 'arr[16]' accessed at index 16, which is out of bounds.", CWE_BUFFER_OVERRUN, Certainty::normal);
        reportError(tok, Severity::warning, "arrayIndexOutOfBoundsCond", "Array 'arr[16]' accessed at index 16, which is out of bounds.", CWE_BUFFER_OVERRUN, Certainty::normal);
        return;
    }

    const Token *condition = nullptr;
    const ValueFlow::Value *index = nullptr;
    for (const ValueFlow::Value& indexValue : indexes) {
        if (!indexValue.errorSeverity() && !mSettings->severity.isEnabled(Severity::warning))
            return;
        if (indexValue.condition)
            condition = indexValue.condition;
        if (!index || !indexValue.errorPath.empty())
            index = &indexValue;
    }

    reportError(getErrorPath(tok, index, "Array index out of bounds"),
                index->errorSeverity() ? Severity::error : Severity::warning,
                index->condition ? "arrayIndexOutOfBoundsCond" : "arrayIndexOutOfBounds",
                arrayIndexMessage(tok, dimensions, indexes, condition),
                CWE_BUFFER_OVERRUN,
                index->isInconclusive() ? Certainty::inconclusive : Certainty::normal);
}

void CheckBufferOverrun::negativeIndexError(const Token* tok,
                                            const std::vector<Dimension>& dimensions,
                                            const std::vector<ValueFlow::Value>& indexes)
{
    if (!tok) {
        reportError(tok, Severity::error, "negativeIndex", "Negative array index", CWE_BUFFER_UNDERRUN, Certainty::normal);
        return;
    }

    const Token *condition = nullptr;
    const ValueFlow::Value *negativeValue = nullptr;
    for (const ValueFlow::Value& indexValue : indexes) {
        if (!indexValue.errorSeverity() && !mSettings->severity.isEnabled(Severity::warning))
            return;
        if (indexValue.condition)
            condition = indexValue.condition;
        if (!negativeValue || !indexValue.errorPath.empty())
            negativeValue = &indexValue;
    }

    reportError(getErrorPath(tok, negativeValue, "Negative array index"),
                negativeValue->errorSeverity() ? Severity::error : Severity::warning,
                "negativeIndex",
                arrayIndexMessage(tok, dimensions, indexes, condition),
                CWE_BUFFER_UNDERRUN,
                negativeValue->isInconclusive() ? Certainty::inconclusive : Certainty::normal);
}

//---------------------------------------------------------------------------

void CheckBufferOverrun::pointerArithmetic()
{
    if (!mSettings->severity.isEnabled(Severity::portability) && !mSettings->isPremiumEnabled("pointerOutOfBounds"))
        return;

    logChecker("CheckBufferOverrun::pointerArithmetic"); // portability

    for (const Token *tok = mTokenizer->tokens(); tok; tok = tok->next()) {
        if (!Token::Match(tok, "+|-"))
            continue;
        if (!tok->valueType() || tok->valueType()->pointer == 0)
            continue;
        if (!tok->isBinaryOp())
            continue;
        if (!tok->astOperand1()->valueType() || !tok->astOperand2()->valueType())
            continue;

        const Token *arrayToken, *indexToken;
        if (tok->astOperand1()->valueType()->pointer > 0) {
            arrayToken = tok->astOperand1();
            indexToken = tok->astOperand2();
        } else {
            arrayToken = tok->astOperand2();
            indexToken = tok->astOperand1();
        }

        if (!indexToken || !indexToken->valueType() || indexToken->valueType()->pointer > 0 || !indexToken->valueType()->isIntegral())
            continue;

        std::vector<Dimension> dimensions;
        ErrorPath errorPath;
        bool mightBeLarger = false;
        MathLib::bigint path = 0;
        if (!getDimensionsEtc(arrayToken, *mSettings, dimensions, errorPath, mightBeLarger, path))
            continue;

        if (tok->str() == "+") {
            // Positive index
            if (!mightBeLarger) { // TODO check arrays with dim 1 also
                const std::vector<const Token *> indexTokens{indexToken};
                const std::vector<ValueFlow::Value>& indexValues =
                    getOverrunIndexValues(tok, arrayToken, dimensions, indexTokens, path);
                if (!indexValues.empty() && !isUnreachableOperand(tok))
                    pointerArithmeticError(tok, indexToken, &indexValues.front());
            }

            if (const ValueFlow::Value *neg = indexToken->getValueLE(-1, *mSettings))
                pointerArithmeticError(tok, indexToken, neg);
        } else if (tok->str() == "-") {
            if (arrayToken->variable() && arrayToken->variable()->isArgument())
                continue;

            const Token *array = arrayToken;
            while (Token::Match(array, ".|::"))
                array = array->astOperand2();
            if (array->variable() && array->variable()->isArray()) {
                const ValueFlow::Value *v = indexToken->getValueGE(1, *mSettings);
                if (v)
                    pointerArithmeticError(tok, indexToken, v);
            }
        }
    }
}

void CheckBufferOverrun::pointerArithmeticError(const Token *tok, const Token *indexToken, const ValueFlow::Value *indexValue)
{
    if (!tok) {
        reportError(tok, Severity::portability, "pointerOutOfBounds", "Pointer arithmetic overflow.", CWE_POINTER_ARITHMETIC_OVERFLOW, Certainty::normal);
        reportError(tok, Severity::portability, "pointerOutOfBoundsCond", "Pointer arithmetic overflow.", CWE_POINTER_ARITHMETIC_OVERFLOW, Certainty::normal);
        return;
    }

    std::string errmsg;
    if (indexValue->condition)
        errmsg = "Undefined behaviour, when '" + indexToken->expressionString() + "' is " + MathLib::toString(indexValue->intvalue) + " the pointer arithmetic '" + tok->expressionString() + "' is out of bounds.";
    else
        errmsg = "Undefined behaviour, pointer arithmetic '" + tok->expressionString() + "' is out of bounds.";

    reportError(getErrorPath(tok, indexValue, "Pointer arithmetic overflow"),
                Severity::portability,
                indexValue->condition ? "pointerOutOfBoundsCond" : "pointerOutOfBounds",
                errmsg,
                CWE_POINTER_ARITHMETIC_OVERFLOW,
                indexValue->isInconclusive() ? Certainty::inconclusive : Certainty::normal);
}

//---------------------------------------------------------------------------

ValueFlow::Value CheckBufferOverrun::getBufferSize(const Token *bufTok) const
{
    if (!bufTok->valueType())
        return ValueFlow::Value(-1);
    const Variable *var = bufTok->variable();

    if (!var || var->dimensions().empty()) {
        const ValueFlow::Value *value = getBufferSizeValue(bufTok);
        if (value)
            return *value;
    }

    if (!var || var->isPointer())
        return ValueFlow::Value(-1);

    const MathLib::bigint dim = std::accumulate(var->dimensions().cbegin(), var->dimensions().cend(), 1LL, [](MathLib::bigint i1, const Dimension &dim) {
        return i1 * dim.num;
    });

    ValueFlow::Value v;
    v.setKnown();
    v.valueType = ValueFlow::Value::ValueType::BUFFER_SIZE;

    if (var->isPointerArray())
        v.intvalue = dim * mSettings->platform.sizeof_pointer;
    else {
        const MathLib::bigint typeSize = bufTok->valueType()->typeSize(mSettings->platform);
        v.intvalue = dim * typeSize;
    }

    return v;
}
//---------------------------------------------------------------------------

static bool checkBufferSize(const Token *ftok, const Library::ArgumentChecks::MinSize &minsize, const std::vector<const Token *> &args, const MathLib::bigint bufferSize, const Settings &settings, const Tokenizer* tokenizer)
{
    const Token * const arg = (minsize.arg > 0 && minsize.arg - 1 < args.size()) ? args[minsize.arg - 1] : nullptr;
    const Token * const arg2 = (minsize.arg2 > 0 && minsize.arg2 - 1 < args.size()) ? args[minsize.arg2 - 1] : nullptr;

    switch (minsize.type) {
    case Library::ArgumentChecks::MinSize::Type::STRLEN:
        if (settings.library.isargformatstr(ftok, minsize.arg)) {
            return getMinFormatStringOutputLength(args, minsize.arg) < bufferSize;
        } else if (arg) {
            const Token *strtoken = arg->getValueTokenMaxStrLength();
            if (strtoken)
                return Token::getStrLength(strtoken) < bufferSize;
        }
        break;
    case Library::ArgumentChecks::MinSize::Type::ARGVALUE: {
        if (arg && arg->hasKnownIntValue()) {
            MathLib::bigint myMinsize = arg->getKnownIntValue();
            const int baseSize = tokenizer->sizeOfType(minsize.baseType);
            if (baseSize != 0)
                myMinsize *= baseSize;
            return myMinsize <= bufferSize;
        }
        break;
    }
    case Library::ArgumentChecks::MinSize::Type::SIZEOF:
        // TODO
        break;
    case Library::ArgumentChecks::MinSize::Type::MUL:
        if (arg && arg2 && arg->hasKnownIntValue() && arg2->hasKnownIntValue())
            return (arg->getKnownIntValue() * arg2->getKnownIntValue()) <= bufferSize;
        break;
    case Library::ArgumentChecks::MinSize::Type::VALUE: {
        MathLib::bigint myMinsize = minsize.value;
        const int baseSize = tokenizer->sizeOfType(minsize.baseType);
        if (baseSize != 0)
            myMinsize *= baseSize;
        return myMinsize <= bufferSize;
    }
    case Library::ArgumentChecks::MinSize::Type::NONE:
        break;
    }
    return true;
}


void CheckBufferOverrun::bufferOverflow()
{
    logChecker("CheckBufferOverrun::bufferOverflow");

    const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
    for (const Scope * scope : symbolDatabase->functionScopes) {
        for (const Token *tok = scope->bodyStart; tok != scope->bodyEnd; tok = tok->next()) {
            if (!Token::Match(tok, "%name% (") || Token::simpleMatch(tok, ") {"))
                continue;
            if (!mSettings->library.hasminsize(tok))
                continue;
            const std::vector<const Token *> args = getArguments(tok);
            for (int argnr = 0; argnr < args.size(); ++argnr) {
                if (!args[argnr]->valueType() || args[argnr]->valueType()->pointer == 0)
                    continue;
                const std::vector<Library::ArgumentChecks::MinSize> *minsizes = mSettings->library.argminsizes(tok, argnr + 1);
                if (!minsizes || minsizes->empty())
                    continue;
                // Get buffer size..
                const Token *argtok = args[argnr];
                while (argtok && argtok->isCast())
                    argtok = argtok->astOperand2() ? argtok->astOperand2() : argtok->astOperand1();
                while (Token::Match(argtok, ".|::"))
                    argtok = argtok->astOperand2();
                if (!argtok || !argtok->variable())
                    continue;
                if (argtok->valueType() && argtok->valueType()->pointer == 0)
                    continue;
                // TODO: strcpy(buf+10, "hello");
                const ValueFlow::Value bufferSize = getBufferSize(argtok);
                if (bufferSize.intvalue <= 0)
                    continue;
                // buffer size == 1 => do not warn for dynamic memory
                if (bufferSize.intvalue == 1 && Token::simpleMatch(argtok->astParent(), ".")) { // TODO: check if parent was allocated dynamically
                    const Token *tok2 = argtok;
                    while (Token::simpleMatch(tok2->astParent(), "."))
                        tok2 = tok2->astParent();
                    while (Token::Match(tok2, "[|."))
                        tok2 = tok2->astOperand1();
                    const Variable *var = tok2 ? tok2->variable() : nullptr;
                    if (var) {
                        if (var->isPointer())
                            continue;
                        if (var->isArgument() && var->isReference())
                            continue;
                    }
                }
                const bool error = std::none_of(minsizes->begin(), minsizes->end(), [&](const Library::ArgumentChecks::MinSize &minsize) {
                    return checkBufferSize(tok, minsize, args, bufferSize.intvalue, *mSettings, mTokenizer);
                });
                if (error)
                    bufferOverflowError(args[argnr], &bufferSize, Certainty::normal);
            }
        }
    }
}

void CheckBufferOverrun::bufferOverflowError(const Token *tok, const ValueFlow::Value *value, Certainty certainty)
{
    reportError(getErrorPath(tok, value, "Buffer overrun"), Severity::error, "bufferAccessOutOfBounds", "Buffer is accessed out of bounds: " + (tok ? tok->expressionString() : "buf"), CWE_BUFFER_OVERRUN, certainty);
}

//---------------------------------------------------------------------------

void CheckBufferOverrun::arrayIndexThenCheck()
{
    if (!mSettings->severity.isEnabled(Severity::portability))
        return;

    logChecker("CheckBufferOverrun::arrayIndexThenCheck");

    const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
    for (const Scope * const scope : symbolDatabase->functionScopes) {
        for (const Token *tok = scope->bodyStart; tok && tok != scope->bodyEnd; tok = tok->next()) {
            if (Token::simpleMatch(tok, "sizeof (")) {
                tok = tok->linkAt(1);
                continue;
            }

            if (Token::Match(tok, "%name% [ %var% ]")) {
                tok = tok->next();

                const int indexID = tok->next()->varId();
                const std::string& indexName(tok->strAt(1));

                // Iterate AST upwards
                const Token* tok2 = tok;
                const Token* tok3 = tok2;
                while (tok2->astParent() && tok2->tokType() != Token::eLogicalOp && tok2->str() != "?") {
                    tok3 = tok2;
                    tok2 = tok2->astParent();
                }

                // Ensure that we ended at a logical operator and that we came from its left side
                if (tok2->tokType() != Token::eLogicalOp || tok2->astOperand1() != tok3)
                    continue;

                // check if array index is ok
                // statement can be closed in parentheses, so "(| " is using
                if (Token::Match(tok2, "&& (| %varid% <|<=", indexID))
                    arrayIndexThenCheckError(tok, indexName);
                else if (Token::Match(tok2, "&& (| %any% >|>= %varid% !!+", indexID))
                    arrayIndexThenCheckError(tok, indexName);
            }
        }
    }
}

void CheckBufferOverrun::arrayIndexThenCheckError(const Token *tok, const std::string &indexName)
{
    reportError(tok, Severity::style, "arrayIndexThenCheck",
                "$symbol:" + indexName + "\n"
                "Array index '$symbol' is used before limits check.\n"
                "Defensive programming: The variable '$symbol' is used as an array index before it "
                "is checked that is within limits. This can mean that the array might be accessed out of bounds. "
                "Reorder conditions such as '(a[i] && i < 10)' to '(i < 10 && a[i])'. That way the array will "
                "not be accessed if the index is out of limits.", CWE_ARRAY_INDEX_THEN_CHECK, Certainty::normal);
}

//---------------------------------------------------------------------------

void CheckBufferOverrun::stringNotZeroTerminated()
{
    // this is currently 'inconclusive'. See TestBufferOverrun::terminateStrncpy3
    if (!mSettings->severity.isEnabled(Severity::warning) || !mSettings->certainty.isEnabled(Certainty::inconclusive))
        return;

    logChecker("CheckBufferOverrun::stringNotZeroTerminated"); // warning,inconclusive

    const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
    for (const Scope * const scope : symbolDatabase->functionScopes) {
        for (const Token *tok = scope->bodyStart; tok && tok != scope->bodyEnd; tok = tok->next()) {
            if (!Token::simpleMatch(tok, "strncpy ("))
                continue;
            const std::vector<const Token *> args = getArguments(tok);
            if (args.size() != 3)
                continue;
            const Token *sizeToken = args[2];
            if (!sizeToken->hasKnownIntValue())
                continue;
            const ValueFlow::Value &bufferSize = getBufferSize(args[0]);
            if (bufferSize.intvalue < 0 || sizeToken->getKnownIntValue() < bufferSize.intvalue)
                continue;
            if (Token::simpleMatch(args[1], "(") && Token::simpleMatch(args[1]->astOperand1(), ". c_str") && args[1]->astOperand1()->astOperand1()) {
                const std::list<ValueFlow::Value>& contValues = args[1]->astOperand1()->astOperand1()->values();
                auto it = std::find_if(contValues.cbegin(), contValues.cend(), [](const ValueFlow::Value& value) {
                    return value.isContainerSizeValue() && !value.isImpossible();
                });
                if (it != contValues.end() && it->intvalue < sizeToken->getKnownIntValue())
                    continue;
            } else {
                const Token* srcValue = args[1]->getValueTokenMaxStrLength();
                if (srcValue && Token::getStrLength(srcValue) < sizeToken->getKnownIntValue())
                    continue;
            }
            // Is the buffer zero terminated after the call?
            bool isZeroTerminated = false;
            for (const Token *tok2 = tok->linkAt(1); tok2 != scope->bodyEnd; tok2 = tok2->next()) {
                if (!Token::simpleMatch(tok2, "] ="))
                    continue;
                const Token *rhs = tok2->next()->astOperand2();
                if (!rhs || !rhs->hasKnownIntValue() || rhs->getKnownIntValue() != 0)
                    continue;
                if (isSameExpression(false, args[0], tok2->link()->astOperand1(), *mSettings, false, false))
                    isZeroTerminated = true;
            }
            if (isZeroTerminated)
                continue;
            // TODO: Locate unsafe string usage..
            terminateStrncpyError(tok, args[0]->expressionString());
        }
    }
}

void CheckBufferOverrun::terminateStrncpyError(const Token *tok, const std::string &varname)
{
    const std::string shortMessage = "The buffer '$symbol' may not be null-terminated after the call to strncpy().";
    reportError(tok, Severity::warning, "terminateStrncpy",
                "$symbol:" + varname + '\n' +
                shortMessage + '\n' +
                shortMessage + ' ' +
                "If the source string's size fits or exceeds the given size, strncpy() does not add a "
                "zero at the end of the buffer. This causes bugs later in the code if the code "
                "assumes buffer is null-terminated.", CWE170, Certainty::inconclusive);
}
//---------------------------------------------------------------------------

void CheckBufferOverrun::argumentSize()
{
    // Check '%type% x[10]' arguments
    if (!mSettings->severity.isEnabled(Severity::warning) && !mSettings->isPremiumEnabled("argumentSize"))
        return;

    logChecker("CheckBufferOverrun::argumentSize"); // warning

    const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
    for (const Scope * const scope : symbolDatabase->functionScopes) {
        for (const Token *tok = scope->bodyStart; tok != scope->bodyEnd; tok = tok->next()) {
            if (!tok->function() || !Token::Match(tok, "%name% ("))
                continue;

            // If argument is '%type% a[num]' then check bounds against num
            const Function *callfunc = tok->function();
            const std::vector<const Token *> callargs = getArguments(tok);
            for (nonneg int paramIndex = 0; paramIndex < callargs.size() && paramIndex < callfunc->argCount(); ++paramIndex) {
                const Variable* const argument = callfunc->getArgumentVar(paramIndex);
                if (!argument || !argument->nameToken() || !argument->isArray())
                    continue;
                if (!argument->valueType() || !callargs[paramIndex]->valueType())
                    continue;
                if (argument->valueType()->type != callargs[paramIndex]->valueType()->type)
                    continue;
                const Token * calldata = callargs[paramIndex];
                while (Token::Match(calldata, "::|."))
                    calldata = calldata->astOperand2();
                if (!calldata->variable() || !calldata->variable()->isArray())
                    continue;
                if (calldata->variable()->dimensions().size() != argument->dimensions().size())
                    continue;
                bool err = false;
                for (std::size_t d = 0; d < argument->dimensions().size(); ++d) {
                    const auto& dim1 = calldata->variable()->dimensions()[d];
                    const auto& dim2 = argument->dimensions()[d];
                    if (!dim1.known || !dim2.known)
                        break;
                    if (dim1.num < dim2.num)
                        err = true;
                }
                if (err)
                    argumentSizeError(tok, tok->str(), paramIndex, callargs[paramIndex]->expressionString(), calldata->variable(), argument);
            }
        }
    }
}

void CheckBufferOverrun::argumentSizeError(const Token *tok, const std::string &functionName, nonneg int paramIndex, const std::string &paramExpression, const Variable *paramVar, const Variable *functionArg)
{
    const std::string strParamNum = std::to_string(paramIndex + 1) + getOrdinalText(paramIndex + 1);
    ErrorPath errorPath;
    errorPath.emplace_back(tok, "Function '" + functionName + "' is called");
    if (functionArg)
        errorPath.emplace_back(functionArg->nameToken(), "Declaration of " + strParamNum + " function argument.");
    if (paramVar)
        errorPath.emplace_back(paramVar->nameToken(), "Passing buffer '" + paramVar->name() + "' to function that is declared here");
    errorPath.emplace_back(tok, "");

    reportError(errorPath, Severity::warning, "argumentSize",
                "$symbol:" + functionName + '\n' +
                "Buffer '" + paramExpression + "' is too small, the function '" + functionName + "' expects a bigger buffer in " + strParamNum + " argument", CWE_ARGUMENT_SIZE, Certainty::normal);
}

//---------------------------------------------------------------------------
// CTU..
//---------------------------------------------------------------------------

// a Clang-built executable will crash when using the anonymous MyFileInfo later on - so put it in a unique namespace for now
// see https://trac.cppcheck.net/ticket/12108 for more details
#ifdef __clang__
inline namespace CheckBufferOverrun_internal
#else
namespace
#endif
{
    /** data for multifile checking */
    class MyFileInfo : public Check::FileInfo {
    public:
        using Check::FileInfo::FileInfo;
        /** unsafe array index usage */
        std::list<CTU::FileInfo::UnsafeUsage> unsafeArrayIndex;

        /** unsafe pointer arithmetics */
        std::list<CTU::FileInfo::UnsafeUsage> unsafePointerArith;

        /** Convert data into xml string */
        std::string toString() const override
        {
            std::string xml;
            if (!unsafeArrayIndex.empty())
                xml = "    <array-index>\n" + CTU::toString(unsafeArrayIndex) + "    </array-index>\n";
            if (!unsafePointerArith.empty())
                xml += "    <pointer-arith>\n" + CTU::toString(unsafePointerArith) + "    </pointer-arith>\n";
            return xml;
        }
    };
}

bool CheckBufferOverrun::isCtuUnsafeBufferUsage(const Settings &settings, const Token *argtok, CTU::FileInfo::Value *offset, int type)
{
    if (!offset)
        return false;
    if (!argtok->valueType() || argtok->valueType()->typeSize(settings.platform) == 0)
        return false;
    const Token *indexTok = nullptr;
    if (type == 1 && Token::Match(argtok, "%name% [") && argtok->astParent() == argtok->next() && !Token::simpleMatch(argtok->linkAt(1), "] ["))
        indexTok = argtok->next()->astOperand2();
    else if (type == 2 && Token::simpleMatch(argtok->astParent(), "+"))
        indexTok = (argtok == argtok->astParent()->astOperand1()) ?
                   argtok->astParent()->astOperand2() :
                   argtok->astParent()->astOperand1();
    if (!indexTok)
        return false;
    if (!indexTok->hasKnownIntValue())
        return false;
    offset->value = indexTok->getKnownIntValue() * argtok->valueType()->typeSize(settings.platform);
    return true;
}

bool CheckBufferOverrun::isCtuUnsafeArrayIndex(const Settings &settings, const Token *argtok, CTU::FileInfo::Value *offset)
{
    return isCtuUnsafeBufferUsage(settings, argtok, offset, 1);
}

bool CheckBufferOverrun::isCtuUnsafePointerArith(const Settings &settings, const Token *argtok, CTU::FileInfo::Value* offset)
{
    return isCtuUnsafeBufferUsage(settings, argtok, offset, 2);
}

/** @brief Parse current TU and extract file info */
Check::FileInfo *CheckBufferOverrun::getFileInfo(const Tokenizer &tokenizer, const Settings &settings) const
{
    const std::list<CTU::FileInfo::UnsafeUsage> &unsafeArrayIndex = CTU::getUnsafeUsage(tokenizer, settings, isCtuUnsafeArrayIndex);
    const std::list<CTU::FileInfo::UnsafeUsage> &unsafePointerArith = CTU::getUnsafeUsage(tokenizer, settings, isCtuUnsafePointerArith);
    if (unsafeArrayIndex.empty() && unsafePointerArith.empty()) {
        return nullptr;
    }
    auto *fileInfo = new MyFileInfo(tokenizer.list.getFiles()[0]);
    fileInfo->unsafeArrayIndex = unsafeArrayIndex;
    fileInfo->unsafePointerArith = unsafePointerArith;
    return fileInfo;
}

Check::FileInfo * CheckBufferOverrun::loadFileInfoFromXml(const tinyxml2::XMLElement *xmlElement) const
{
    // cppcheck-suppress shadowFunction - TODO: fix this
    const std::string arrayIndex("array-index");
    const std::string pointerArith("pointer-arith");

    auto *fileInfo = new MyFileInfo;
    for (const tinyxml2::XMLElement *e = xmlElement->FirstChildElement(); e; e = e->NextSiblingElement()) {
        const char* name = e->Name();
        if (name == arrayIndex)
            fileInfo->unsafeArrayIndex = CTU::loadUnsafeUsageListFromXml(e);
        else if (name == pointerArith)
            fileInfo->unsafePointerArith = CTU::loadUnsafeUsageListFromXml(e);
    }

    if (fileInfo->unsafeArrayIndex.empty() && fileInfo->unsafePointerArith.empty()) {
        delete fileInfo;
        return nullptr;
    }

    return fileInfo;
}

/** @brief Analyse all file infos for all TU */
bool CheckBufferOverrun::analyseWholeProgram(const CTU::FileInfo &ctu, const std::list<Check::FileInfo*> &fileInfo, const Settings& settings, ErrorLogger &errorLogger)
{
    CheckBufferOverrun dummy(nullptr, &settings, &errorLogger);
    dummy.
    logChecker("CheckBufferOverrun::analyseWholeProgram");

    if (fileInfo.empty())
        return false;

    const std::map<std::string, std::list<const CTU::FileInfo::CallBase *>> callsMap = ctu.getCallsMap();

    bool foundErrors = false;

    for (const Check::FileInfo* fi1 : fileInfo) {
        const auto *fi = dynamic_cast<const MyFileInfo*>(fi1);
        if (!fi)
            continue;
        for (const CTU::FileInfo::UnsafeUsage &unsafeUsage : fi->unsafeArrayIndex)
            foundErrors |= analyseWholeProgram1(callsMap, unsafeUsage, 1, errorLogger, settings.maxCtuDepth, fi->file0);
        for (const CTU::FileInfo::UnsafeUsage &unsafeUsage : fi->unsafePointerArith)
            foundErrors |= analyseWholeProgram1(callsMap, unsafeUsage, 2, errorLogger, settings.maxCtuDepth, fi->file0);
    }
    return foundErrors;
}

bool CheckBufferOverrun::analyseWholeProgram1(const std::map<std::string, std::list<const CTU::FileInfo::CallBase *>> &callsMap, const CTU::FileInfo::UnsafeUsage &unsafeUsage,
                                              int type, ErrorLogger &errorLogger, int maxCtuDepth, const std::string& file0)
{
    const CTU::FileInfo::FunctionCall *functionCall = nullptr;

    const std::list<ErrorMessage::FileLocation> &locationList =
        CTU::FileInfo::getErrorPath(CTU::FileInfo::InvalidValueType::bufferOverflow,
                                    unsafeUsage,
                                    callsMap,
                                    "Using argument ARG",
                                    &functionCall,
                                    false,
                                    maxCtuDepth);
    if (locationList.empty())
        return false;

    const char *errorId = nullptr;
    std::string errmsg;
    CWE cwe(0);

    if (type == 1) {
        errorId = "ctuArrayIndex";
        if (unsafeUsage.value > 0)
            errmsg = "Array index out of bounds; '" + unsafeUsage.myArgumentName + "' buffer size is " + MathLib::toString(functionCall->callArgValue.value) + " and it is accessed at offset " + MathLib::toString(unsafeUsage.value) + ".";
        else
            errmsg = "Array index out of bounds; buffer '" + unsafeUsage.myArgumentName + "' is accessed at offset " + MathLib::toString(unsafeUsage.value) + ".";
        cwe = (unsafeUsage.value > 0) ? CWE_BUFFER_OVERRUN : CWE_BUFFER_UNDERRUN;
    } else {
        errorId = "ctuPointerArith";
        errmsg = "Pointer arithmetic overflow; '" + unsafeUsage.myArgumentName + "' buffer size is " + MathLib::toString(functionCall->callArgValue.value);
        cwe = CWE_POINTER_ARITHMETIC_OVERFLOW;
    }

    const ErrorMessage errorMessage(locationList,
                                    file0,
                                    Severity::error,
                                    errmsg,
                                    errorId,
                                    cwe, Certainty::normal);
    errorLogger.reportErr(errorMessage);

    return true;
}

void CheckBufferOverrun::objectIndex()
{
    logChecker("CheckBufferOverrun::objectIndex");
    const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
    for (const Scope *functionScope : symbolDatabase->functionScopes) {
        for (const Token *tok = functionScope->bodyStart; tok != functionScope->bodyEnd; tok = tok->next()) {
            if (!Token::simpleMatch(tok, "["))
                continue;
            const Token *obj = tok->astOperand1();
            const Token *idx = tok->astOperand2();
            if (!idx || !obj)
                continue;
            if (idx->hasKnownIntValue()) {
                if (idx->getKnownIntValue() == 0)
                    continue;
            }
            if (idx->hasKnownIntValue() && idx->getKnownIntValue() == 0)
                continue;

            std::vector<ValueFlow::Value> values = ValueFlow::getLifetimeObjValues(obj, false, -1);
            for (const ValueFlow::Value& v:values) {
                if (v.lifetimeKind != ValueFlow::Value::LifetimeKind::Address)
                    continue;
                const Variable *var = v.tokvalue->variable();
                if (!var)
                    continue;
                if (var->isReference())
                    continue;
                if (var->isRValueReference())
                    continue;
                if (var->isArray())
                    continue;
                if (var->isPointer()) {
                    if (!var->valueType())
                        continue;
                    if (!obj->valueType())
                        continue;
                    if (var->valueType()->pointer > obj->valueType()->pointer)
                        continue;
                }
                if (obj->valueType() && var->valueType() && (obj->isCast() || (obj->isCpp() && isCPPCast(obj)) || obj->valueType()->pointer)) { // allow cast to a different type
                    const auto varSize = var->valueType()->typeSize(mSettings->platform);
                    if (varSize == 0)
                        continue;
                    if (obj->valueType()->type != var->valueType()->type) {
                        if (ValueFlow::isOutOfBounds(makeSizeValue(varSize, v.path), idx).empty())
                            continue;
                    }
                }
                if (v.path != 0) {
                    std::vector<ValueFlow::Value> idxValues;
                    std::copy_if(idx->values().cbegin(),
                                 idx->values().cend(),
                                 std::back_inserter(idxValues),
                                 [&](const ValueFlow::Value& vidx) {
                        if (!vidx.isIntValue())
                            return false;
                        return vidx.path == v.path || vidx.path == 0;
                    });
                    if (std::any_of(idxValues.cbegin(), idxValues.cend(), [&](const ValueFlow::Value& vidx) {
                        if (vidx.isImpossible())
                            return (vidx.intvalue == 0);
                        return (vidx.intvalue != 0);
                    })) {
                        objectIndexError(tok, &v, idx->hasKnownIntValue());
                    }
                } else {
                    objectIndexError(tok, &v, idx->hasKnownIntValue());
                }
            }
        }
    }
}

void CheckBufferOverrun::objectIndexError(const Token *tok, const ValueFlow::Value *v, bool known)
{
    ErrorPath errorPath;
    std::string name;
    if (v) {
        const Token* expr = v->tokvalue;
        while (Token::simpleMatch(expr->astParent(), "."))
            expr = expr->astParent();
        name = expr->expressionString();
        errorPath = v->errorPath;
    }
    errorPath.emplace_back(tok, "");
    std::string verb = known ? "is" : "might be";
    reportError(errorPath,
                known ? Severity::error : Severity::warning,
                "objectIndex",
                "The address of variable '" + name + "' " + verb + " accessed at non-zero index.",
                CWE758,
                Certainty::normal);
}

static bool isVLAIndex(const Token* tok)
{
    if (!tok)
        return false;
    if (tok->varId() != 0U)
        return true;
    if (tok->str() == "?") {
        // this is a VLA index if both expressions around the ":" is VLA index
        return tok->astOperand2() &&
               tok->astOperand2()->str() == ":" &&
               isVLAIndex(tok->astOperand2()->astOperand1()) &&
               isVLAIndex(tok->astOperand2()->astOperand2());
    }
    return isVLAIndex(tok->astOperand1()) || isVLAIndex(tok->astOperand2());
}

void CheckBufferOverrun::negativeArraySize()
{
    logChecker("CheckBufferOverrun::negativeArraySize");
    const SymbolDatabase* symbolDatabase = mTokenizer->getSymbolDatabase();
    for (const Variable* var : symbolDatabase->variableList()) {
        if (!var || !var->isArray())
            continue;
        const Token* const nameToken = var->nameToken();
        if (!Token::Match(nameToken, "%var% [") || !nameToken->next()->astOperand2())
            continue;
        const ValueFlow::Value* sz = nameToken->next()->astOperand2()->getValueLE(-1, *mSettings);
        // don't warn about constant negative index because that is a compiler error
        if (sz && isVLAIndex(nameToken->next()->astOperand2()))
            negativeArraySizeError(nameToken);
    }

    for (const Scope* functionScope : symbolDatabase->functionScopes) {
        for (const Token* tok = functionScope->bodyStart; tok != functionScope->bodyEnd; tok = tok->next()) {
            if (!tok->isKeyword() || tok->str() != "new" || !tok->astOperand1() || tok->astOperand1()->str() != "[")
                continue;
            const Token* valOperand = tok->astOperand1()->astOperand2();
            if (!valOperand)
                continue;
            const ValueFlow::Value* sz = valOperand->getValueLE(-1, *mSettings);
            if (sz)
                negativeMemoryAllocationSizeError(tok, sz);
        }
    }
}

void CheckBufferOverrun::negativeArraySizeError(const Token* tok)
{
    const std::string arrayName = tok ? tok->expressionString() : std::string();
    const std::string line1 = arrayName.empty() ? std::string() : ("$symbol:" + arrayName + '\n');
    reportError(tok, Severity::error, "negativeArraySize",
                line1 +
                "Declaration of array '" + arrayName + "' with negative size is undefined behaviour", CWE758, Certainty::normal);
}

void CheckBufferOverrun::negativeMemoryAllocationSizeError(const Token* tok, const ValueFlow::Value* value)
{
    const std::string msg = "Memory allocation size is negative.";
    const ErrorPath errorPath = getErrorPath(tok, value, msg);
    const bool inconclusive = value != nullptr && !value->isKnown();
    reportError(errorPath, inconclusive ? Severity::warning : Severity::error, "negativeMemoryAllocationSize",
                msg, CWE131, inconclusive ? Certainty::inconclusive : Certainty::normal);
}

void CheckBufferOverrun::runChecks(const Tokenizer &tokenizer, ErrorLogger *errorLogger)
{
    CheckBufferOverrun checkBufferOverrun(&tokenizer, &tokenizer.getSettings(), errorLogger);
    checkBufferOverrun.arrayIndex();
    checkBufferOverrun.pointerArithmetic();
    checkBufferOverrun.bufferOverflow();
    checkBufferOverrun.arrayIndexThenCheck();
    checkBufferOverrun.stringNotZeroTerminated();
    checkBufferOverrun.objectIndex();
    checkBufferOverrun.argumentSize();
    checkBufferOverrun.negativeArraySize();
}

void CheckBufferOverrun::getErrorMessages(ErrorLogger *errorLogger, const Settings *settings) const
{
    CheckBufferOverrun c(nullptr, settings, errorLogger);
    c.arrayIndexError(nullptr, std::vector<Dimension>(), std::vector<ValueFlow::Value>());
    c.pointerArithmeticError(nullptr, nullptr, nullptr);
    c.negativeIndexError(nullptr, std::vector<Dimension>(), std::vector<ValueFlow::Value>());
    c.arrayIndexThenCheckError(nullptr, "i");
    c.bufferOverflowError(nullptr, nullptr, Certainty::normal);
    c.objectIndexError(nullptr, nullptr, true);
    c.argumentSizeError(nullptr, "function", 1, "buffer", nullptr, nullptr);
    c.negativeMemoryAllocationSizeError(nullptr, nullptr);
    c.negativeArraySizeError(nullptr);
}