summaryrefslogtreecommitdiff
path: root/compilerplugins/clang/buriedassign.cxx
blob: 2974f84be998bbedd00e74c128ce343187ec21fb (plain)
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
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
 * This file is part of the LibreOffice project.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */

#include <cassert>
#include <string>
#include <iostream>
#include <unordered_set>

#include "plugin.hxx"
#include "check.hxx"
#include "config_clang.h"
#include "clang/AST/CXXInheritance.h"
#include "clang/AST/StmtVisitor.h"

// This checker aims to pull buried assignments out of complex expressions,
// where they are quite hard to notice amidst the other conditional logic.

namespace
{
class BuriedAssign : public loplugin::FilteringPlugin<BuriedAssign>
{
public:
    explicit BuriedAssign(loplugin::InstantiationData const& data)
        : FilteringPlugin(data)
    {
    }

    virtual void run() override
    {
        std::string fn(handler.getMainFileName());
        loplugin::normalizeDotDotInFilePath(fn);

        // code where I don't have a better alternative
        if (fn == SRCDIR "/sal/osl/unx/profile.cxx")
            return;
        if (fn == SRCDIR "/sal/rtl/uri.cxx")
            return;
        if (fn == SRCDIR "/sal/osl/unx/process.cxx")
            return;
        if (fn == SRCDIR "/sal/rtl/bootstrap.cxx")
            return;
        if (fn == SRCDIR "/i18npool/source/textconversion/genconv_dict.cxx")
            return;
        if (fn == SRCDIR "/soltools/cpp/_macro.c")
            return;
        if (fn == SRCDIR "/stoc/source/inspect/introspection.cxx")
            return;
        if (fn == SRCDIR "/tools/source/fsys/urlobj.cxx")
            return;
        if (fn == SRCDIR "/sax/source/tools/fastserializer.cxx")
            return;
        if (fn == SRCDIR "/svl/source/crypto/cryptosign.cxx")
            return;
        if (fn == SRCDIR "/svl/source/numbers/zforfind.cxx")
            return;
        if (fn == SRCDIR "/svl/source/numbers/zformat.cxx")
            return;
        if (fn == SRCDIR "/svl/source/numbers/zforscan.cxx")
            return;
        if (fn == SRCDIR "/svl/source/numbers/zforlist.cxx")
            return;
        if (fn == SRCDIR "/vcl/source/window/debugevent.cxx")
            return;
        if (fn == SRCDIR "/vcl/source/control/scrbar.cxx")
            return;
        if (fn == SRCDIR "/vcl/source/gdi/bitmap3.cxx")
            return;
        if (fn == SRCDIR "/vcl/source/window/menu.cxx")
            return;
        if (fn == SRCDIR "/vcl/source/fontsubset/sft.cxx")
            return;
        if (fn == SRCDIR "/vcl/unx/generic/print/prtsetup.cxx")
            return;
        if (fn == SRCDIR "/svtools/source/brwbox/brwbox1.cxx")
            return;
        if (fn == SRCDIR "/svtools/source/control/valueset.cxx")
            return;
        if (fn == SRCDIR "/basic/source/runtime/iosys.cxx")
            return;
        if (fn == SRCDIR "/basic/source/runtime/runtime.cxx")
            return;
        if (fn == SRCDIR "/basic/source/sbx/sbxvalue.cxx")
            return;
        if (fn == SRCDIR "/sfx2/source/dialog/templdlg.cxx")
            return;
        if (fn == SRCDIR "/sfx2/source/view/viewfrm.cxx")
            return;
        if (fn == SRCDIR "/connectivity/source/commontools/dbtools.cxx")
            return;
        if (fn == SRCDIR "/xmloff/source/style/xmlnumfi.cxx")
            return;
        if (fn == SRCDIR "/xmloff/source/style/xmlnumfe .cxx")
            return;
        if (fn == SRCDIR "/editeng/source/items/textitem.cxx")
            return;
        if (fn == SRCDIR "/editeng/source/rtf/rtfitem.cxx")
            return;
        if (fn == SRCDIR "/editeng/source/rtf/svxrtf.cxx")
            return;
        if (fn == SRCDIR "/editeng/source/misc/svxacorr.cxx")
            return;
        if (fn == SRCDIR "/svx/source/items/numfmtsh.cxx")
            return;
        if (fn == SRCDIR "/svx/source/dialog/hdft.cxx")
            return;
        if (fn == SRCDIR "/cui/source/dialogs/insdlg.cxx")
            return;
        if (fn == SRCDIR "/cui/source/tabpages/paragrph.cxx")
            return;
        if (fn == SRCDIR "/cui/source/tabpages/page.cxx")
            return;
        if (fn == SRCDIR "/cui/source/tabpages/border.cxx")
            return;
        if (fn == SRCDIR "/cui/source/tabpages/chardlg.cxx")
            return;
        if (fn == SRCDIR "/cui/source/tabpages/numpages.cxx")
            return;
        if (fn == SRCDIR "/cui/source/dialogs/SpellDialog.cxx")
            return;
        if (fn == SRCDIR "/oox/source/drawingml/diagram/diagramlayoutatoms.cxx")
            return;
        if (fn == SRCDIR "/dbaccess/source/core/dataaccess/intercept.cxx")
            return;
        if (fn == SRCDIR "/sw/writerfilter/dmapper/DomainMapper.cxx")
            return;
        if (fn == SRCDIR "/sw/writerfilter/dmapper/DomainMapper_Impl.cxx")
            return;
        if (fn == SRCDIR "/lotuswordpro/source/filter/lwptablelayout.cxx")
            return;
        if (fn == SRCDIR "/i18npool/source/characterclassification/cclass_unicode_parser.cxx")
            return;
        if (fn == SRCDIR "/sd/source/filter/eppt/pptx-animations.cxx")
            return;
        if (fn == SRCDIR "/sc/source/core/tool/address.cxx")
            return;
        if (fn == SRCDIR "/sc/source/core/tool/interpr1.cxx")
            return;
        if (fn == SRCDIR "/sc/source/core/tool/interpr4.cxx")
            return;
        if (fn == SRCDIR "/sc/source/core/tool/interpr5.cxx")
            return;
        if (fn == SRCDIR "/sc/source/core/tool/compiler.cxx")
            return;
        if (fn == SRCDIR "/sc/source/core/data/table4.cxx")
            return;
        if (fn == SRCDIR "/sc/source/ui/drawfunc/fudraw.cxx")
            return;
        if (fn == SRCDIR "/sc/source/filter/xml/xmlcelli.cxx")
            return;
        if (fn == SRCDIR "/sc/source/ui/miscdlgs/crnrdlg.cxx")
            return;
        if (fn == SRCDIR "/sc/source/ui/app/inputwin.cxx")
            return;
        if (fn == SRCDIR "/sc/source/ui/view/viewfun2.cxx")
            return;
        if (fn == SRCDIR "/sc/source/ui/unoobj/docuno.cxx")
            return;
        if (fn == SRCDIR "/sc/source/ui/view/gridwin.cxx")
            return;
        if (fn == SRCDIR "/sw/source/core/crsr/callnk.cxx")
            return;
        if (fn == SRCDIR "/sw/source/core/crsr/findtxt.cxx")
            return;
        if (fn == SRCDIR "/sw/source/core/crsr/crsrsh.cxx")
            return;
        if (fn == SRCDIR "/sw/source/core/crsr/crstrvl.cxx")
            return;
        if (fn == SRCDIR "/sw/source/core/doc/doccomp.cxx")
            return;
        if (fn == SRCDIR "/sw/source/core/doc/docedt.cxx")
            return;
        if (fn == SRCDIR "/sw/source/core/doc/docfly.cxx")
            return;
        if (fn == SRCDIR "/sw/source/core/doc/DocumentRedlineManager.cxx")
            return;
        if (fn == SRCDIR "/sw/source/core/doc/notxtfrm.cxx")
            return;
        if (fn == SRCDIR "/sw/source/core/docnode/node.cxx")
            return;
        if (fn == SRCDIR "/sw/source/core/layout/ftnfrm.cxx")
            return;
        if (fn == SRCDIR "/sw/source/core/table/swtable.cxx")
            return;
        if (fn == SRCDIR "/sw/source/core/unocore/unoframe.cxx")
            return;
        if (fn == SRCDIR "/sw/source/filter/xml/xmlimp.cxx")
            return;
        if (fn == SRCDIR "/sw/source/uibase/docvw/edtwin.cxx")
            return;
        if (fn == SRCDIR "/sw/source/uibase/shells/langhelper.cxx")
            return;
        if (fn == SRCDIR "/sw/source/uibase/shells/tabsh.cxx")
            return;
        if (fn == SRCDIR "/sw/source/uibase/shells/textsh1.cxx")
            return;
        if (fn == SRCDIR "/sw/source/uibase/uiview/view2.cxx")
            return;
        if (fn == SRCDIR "/starmath/source/mathtype.cxx")
            return;
        if (fn == SRCDIR "/starmath/source/mathmlexport.cxx")
            return;
        if (fn == SRCDIR "/starmath/source/view.cxx")
            return;
        if (fn == SRCDIR "/xmlhelp/source/treeview/tvread.cxx")
            return;
        TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
    }

    bool VisitBinaryOperator(BinaryOperator const*);
    bool VisitCXXOperatorCallExpr(CXXOperatorCallExpr const*);
    bool VisitCompoundStmt(CompoundStmt const*);
    bool VisitIfStmt(IfStmt const*);
    bool VisitLabelStmt(LabelStmt const*);
    bool VisitForStmt(ForStmt const*);
    bool VisitCXXForRangeStmt(CXXForRangeStmt const*);
    bool VisitWhileStmt(WhileStmt const*);
    bool VisitDoStmt(DoStmt const*);
    bool VisitCaseStmt(CaseStmt const*);
    bool VisitDefaultStmt(DefaultStmt const*);
    bool VisitVarDecl(VarDecl const*);
    bool VisitCXXFoldExpr(CXXFoldExpr const*);

private:
    void MarkIfAssignment(Stmt const*);
    void MarkAll(Stmt const*);
    void MarkConditionForControlLoops(Expr const*);

    std::unordered_set<const Stmt*> m_handled;
};

static bool isAssignmentOp(clang::BinaryOperatorKind op)
{
    // We ignore BO_ShrAssign i.e. >>= because we use that everywhere for
    // extracting data from css::uno::Any
    return op == BO_Assign || op == BO_MulAssign || op == BO_DivAssign || op == BO_RemAssign
           || op == BO_AddAssign || op == BO_SubAssign || op == BO_ShlAssign || op == BO_AndAssign
           || op == BO_XorAssign || op == BO_OrAssign;
}

static bool isAssignmentOp(clang::OverloadedOperatorKind Opc)
{
    // Same logic as CXXOperatorCallExpr::isAssignmentOp(), which our supported clang
    // doesn't have yet.
    // Except that we ignore OO_GreaterGreaterEqual i.e. >>= because we use that everywhere for
    // extracting data from css::uno::Any
    return Opc == OO_Equal || Opc == OO_StarEqual || Opc == OO_SlashEqual || Opc == OO_PercentEqual
           || Opc == OO_PlusEqual || Opc == OO_MinusEqual || Opc == OO_LessLessEqual
           || Opc == OO_AmpEqual || Opc == OO_CaretEqual || Opc == OO_PipeEqual;
}

static const Expr* IgnoreImplicitAndConversionOperator(const Expr* expr)
{
    expr = expr->IgnoreImplicit();
    if (auto memberCall = dyn_cast<CXXMemberCallExpr>(expr))
    {
        if (auto conversionDecl = dyn_cast_or_null<CXXConversionDecl>(memberCall->getMethodDecl()))
        {
            if (!conversionDecl->isExplicit())
                expr = memberCall->getImplicitObjectArgument()->IgnoreImplicit();
        }
    }
    return expr;
}

bool BuriedAssign::VisitBinaryOperator(BinaryOperator const* binaryOp)
{
    if (ignoreLocation(binaryOp))
        return true;
    if (binaryOp->getBeginLoc().isMacroID())
        return true;
    if (!isAssignmentOp(binaryOp->getOpcode()))
        return true;
    auto expr = IgnoreImplicitAndConversionOperator(binaryOp->getRHS());
    if (auto rhs = dyn_cast<BinaryOperator>(expr))
    {
        // Ignore chained assignment.
        // TODO limit this to only ordinary assignment
        if (isAssignmentOp(rhs->getOpcode()))
            m_handled.insert(rhs);
    }
    else if (auto rhs = dyn_cast<CXXOperatorCallExpr>(expr))
    {
        // Ignore chained assignment.
        // TODO limit this to only ordinary assignment
        if (isAssignmentOp(rhs->getOperator()))
            m_handled.insert(rhs);
    }
    else if (auto cxxConstruct = dyn_cast<CXXConstructExpr>(expr))
    {
        if (cxxConstruct->getNumArgs() == 1)
            MarkIfAssignment(cxxConstruct->getArg(0));
    }
    if (!m_handled.insert(binaryOp).second)
        return true;

    // assignment in constructor
    StringRef aFileName = getFilenameOfLocation(
        compiler.getSourceManager().getSpellingLoc(binaryOp->getBeginLoc()));
    if (loplugin::hasPathnamePrefix(aFileName, SRCDIR "/include/comphelper/flagguard.hxx"))
        return true;

    report(DiagnosticsEngine::Warning, "buried assignment, rather put on own line",
           binaryOp->getBeginLoc())
        << binaryOp->getSourceRange();
    //getParentStmt(getParentStmt(getParentStmt(getParentStmt(getParentStmt(getParentStmt(binaryOp))))))->dump();
    return true;
}

bool BuriedAssign::VisitCXXOperatorCallExpr(CXXOperatorCallExpr const* cxxOper)
{
    if (ignoreLocation(cxxOper))
        return true;
    if (cxxOper->getBeginLoc().isMacroID())
        return true;
    if (!isAssignmentOp(cxxOper->getOperator()))
        return true;
    auto expr = IgnoreImplicitAndConversionOperator(cxxOper->getArg(1));
    if (auto rhs = dyn_cast<BinaryOperator>(expr))
    {
        // Ignore chained assignment.
        // TODO limit this to only ordinary assignment
        if (isAssignmentOp(rhs->getOpcode()))
            m_handled.insert(rhs);
    }
    else if (auto rhs = dyn_cast<CXXOperatorCallExpr>(expr))
    {
        // Ignore chained assignment.
        // TODO limit this to only ordinary assignment
        if (isAssignmentOp(rhs->getOperator()))
            m_handled.insert(rhs);
    }
    else if (auto cxxConstruct = dyn_cast<CXXConstructExpr>(expr))
    {
        if (cxxConstruct->getNumArgs() == 1)
            MarkIfAssignment(cxxConstruct->getArg(0));
    }
    if (!m_handled.insert(cxxOper).second)
        return true;
    report(DiagnosticsEngine::Warning, "buried assignment, rather put on own line",
           cxxOper->getBeginLoc())
        << cxxOper->getSourceRange();
    //getParentStmt(getParentStmt(getParentStmt(getParentStmt(getParentStmt(cxxOper)))))->dump();
    return true;
}

bool BuriedAssign::VisitCompoundStmt(CompoundStmt const* compoundStmt)
{
    if (ignoreLocation(compoundStmt))
        return true;
    for (auto i = compoundStmt->child_begin(); i != compoundStmt->child_end(); ++i)
    {
        if (auto expr = dyn_cast<Expr>(*i))
        {
            expr = expr->IgnoreImplicit();
            if (auto binaryOp = dyn_cast<BinaryOperator>(expr))
            {
                // ignore comma-chained statements at this level
                if (binaryOp->getOpcode() == BO_Comma)
                {
                    MarkIfAssignment(binaryOp->getLHS());
                    MarkIfAssignment(binaryOp->getRHS());
                    continue;
                }
            }
            MarkIfAssignment(expr);
        }
    }
    return true;
}

void BuriedAssign::MarkIfAssignment(Stmt const* stmt)
{
    if (auto expr = dyn_cast_or_null<Expr>(stmt))
    {
        expr = expr->IgnoreImplicit();
        if (auto binaryOp = dyn_cast<BinaryOperator>(expr))
        {
            if (isAssignmentOp(binaryOp->getOpcode()))
            {
                m_handled.insert(expr);
                MarkIfAssignment(binaryOp->getRHS()); // in case it is chained
            }
            else if (binaryOp->getOpcode() == BO_Comma)
            {
                MarkIfAssignment(binaryOp->getLHS());
                MarkIfAssignment(binaryOp->getRHS());
            }
        }
        else if (auto cxxOper = dyn_cast<CXXOperatorCallExpr>(expr))
        {
            if (isAssignmentOp(cxxOper->getOperator()))
            {
                m_handled.insert(expr);
                MarkIfAssignment(cxxOper->getArg(1)); // in case it is chained
            }
        }
    }
}

void BuriedAssign::MarkAll(Stmt const* stmt)
{
    m_handled.insert(stmt);
    for (auto it = stmt->child_begin(); it != stmt->child_end(); ++it)
        MarkAll(*it);
}

/**
 * Restrict this to cases where the buried assignment is part of the first
 * condition inside the if condition. Other cases tend to be too hard
 * too extract (notably in sw/)
 */
bool BuriedAssign::VisitIfStmt(IfStmt const* ifStmt)
{
    if (ignoreLocation(ifStmt))
        return true;
    MarkIfAssignment(ifStmt->getThen());
    MarkIfAssignment(ifStmt->getElse());

    auto expr = ifStmt->getCond();
    expr = IgnoreImplicitAndConversionOperator(expr);
    expr = expr->IgnoreParens();
    expr = IgnoreImplicitAndConversionOperator(expr);
    MarkAll(expr);

    if (auto binaryOp = dyn_cast<BinaryOperator>(expr))
    {
        if (isAssignmentOp(binaryOp->getOpcode()))
        {
            report(DiagnosticsEngine::Warning, "buried assignment, rather put on own line",
                   expr->getBeginLoc())
                << expr->getSourceRange();
        }
        else if (binaryOp->isComparisonOp())
        {
            if (auto binaryOp2
                = dyn_cast<BinaryOperator>(binaryOp->getLHS()->IgnoreParenImpCasts()))
            {
                if (!binaryOp->getRHS()->isValueDependent()
                    && binaryOp->getRHS()->isCXX11ConstantExpr(compiler.getASTContext())
                    && isAssignmentOp(binaryOp2->getOpcode()))
                    report(DiagnosticsEngine::Warning, "buried assignment, rather put on own line",
                           expr->getBeginLoc())
                        << expr->getSourceRange();
            }
            if (auto binaryOp2
                = dyn_cast<BinaryOperator>(binaryOp->getRHS()->IgnoreParenImpCasts()))
            {
                if (!binaryOp->getLHS()->isValueDependent()
                    && binaryOp->getLHS()->isCXX11ConstantExpr(compiler.getASTContext())
                    && isAssignmentOp(binaryOp2->getOpcode()))
                    report(DiagnosticsEngine::Warning, "buried assignment, rather put on own line",
                           expr->getBeginLoc())
                        << expr->getSourceRange();
            }
        }
        else if (binaryOp->isLogicalOp())
        {
            if (auto binaryOp2
                = dyn_cast<BinaryOperator>(binaryOp->getLHS()->IgnoreParenImpCasts()))
            {
                if (isAssignmentOp(binaryOp2->getOpcode()))
                    report(DiagnosticsEngine::Warning, "buried assignment, rather put on own line",
                           expr->getBeginLoc())
                        << expr->getSourceRange();
            }
        }
    }
    else if (auto operCall = dyn_cast<CXXOperatorCallExpr>(expr))
    {
        // Ignore chained assignment.
        // TODO limit this to only ordinary assignment
        if (isAssignmentOp(operCall->getOperator()))
        {
            report(DiagnosticsEngine::Warning, "buried assignment, rather put on own line",
                   expr->getBeginLoc())
                << expr->getSourceRange();
        }
    }

    return true;
}

bool BuriedAssign::VisitCaseStmt(CaseStmt const* stmt)
{
    if (ignoreLocation(stmt))
        return true;
    MarkIfAssignment(stmt->getSubStmt());
    return true;
}

bool BuriedAssign::VisitDefaultStmt(DefaultStmt const* stmt)
{
    if (ignoreLocation(stmt))
        return true;
    MarkIfAssignment(stmt->getSubStmt());
    return true;
}

bool BuriedAssign::VisitWhileStmt(WhileStmt const* stmt)
{
    if (ignoreLocation(stmt))
        return true;
    MarkConditionForControlLoops(stmt->getCond());
    MarkIfAssignment(stmt->getBody());
    return true;
}

bool BuriedAssign::VisitDoStmt(DoStmt const* stmt)
{
    if (ignoreLocation(stmt))
        return true;
    MarkConditionForControlLoops(stmt->getCond());
    MarkIfAssignment(stmt->getBody());
    return true;
}

/** stuff like
 *    while ((x = foo())
 * and
 *    while ((x = foo() < 0)
 * is considered idiomatic.
 */
void BuriedAssign::MarkConditionForControlLoops(Expr const* expr)
{
    if (!expr)
        return;
    expr = expr->IgnoreImplicit();

    if (auto binaryOp = dyn_cast<BinaryOperator>(expr))
    {
        // ignore comma-chained statements at this level
        if (binaryOp->getOpcode() == BO_Comma)
        {
            MarkConditionForControlLoops(binaryOp->getLHS());
            MarkConditionForControlLoops(binaryOp->getRHS());
            return;
        }
    }

    // unwrap conversion to bool
    if (auto memberCall = dyn_cast<CXXMemberCallExpr>(expr))
    {
        if (memberCall->getMethodDecl() && isa<CXXConversionDecl>(memberCall->getMethodDecl()))
        {
            // TODO check that the conversion is converting to bool
            expr = memberCall->getImplicitObjectArgument()->IgnoreImplicit();
        }
    }

    if (auto binaryOp = dyn_cast<BinaryOperator>(expr))
    {
        // handle: ((xxx = foo()) != error)
        if (binaryOp->isComparisonOp())
        {
            MarkIfAssignment(binaryOp->getLHS()->IgnoreImplicit()->IgnoreParens());
            MarkIfAssignment(binaryOp->getRHS()->IgnoreImplicit()->IgnoreParens());
        }
    }
    else if (auto cxxOper = dyn_cast<CXXOperatorCallExpr>(expr))
    {
        // handle: ((xxx = foo()) != error)
        if (cxxOper->isComparisonOp())
        {
            MarkIfAssignment(cxxOper->getArg(0)->IgnoreImplicit()->IgnoreParens());
            MarkIfAssignment(cxxOper->getArg(1)->IgnoreImplicit()->IgnoreParens());
        }
        // handle: (!(xxx = foo()))
        else if (cxxOper->getOperator() == OO_Exclaim)
            MarkIfAssignment(cxxOper->getArg(0)->IgnoreImplicit()->IgnoreParens());
    }
    else if (auto parenExpr = dyn_cast<ParenExpr>(expr))
    {
        // handle: ((xxx = foo()))
        MarkIfAssignment(parenExpr->getSubExpr()->IgnoreImplicit());
    }
    else if (auto unaryOp = dyn_cast<UnaryOperator>(expr))
    {
        // handle: (!(xxx = foo()))
        MarkIfAssignment(unaryOp->getSubExpr()->IgnoreImplicit()->IgnoreParens());
    }
    else
        MarkIfAssignment(expr);
}

bool BuriedAssign::VisitForStmt(ForStmt const* stmt)
{
    if (ignoreLocation(stmt))
        return true;
    MarkIfAssignment(stmt->getInit());
    MarkConditionForControlLoops(stmt->getCond());
    MarkIfAssignment(stmt->getInc());
    MarkIfAssignment(stmt->getBody());
    return true;
}

bool BuriedAssign::VisitCXXForRangeStmt(CXXForRangeStmt const* stmt)
{
    if (ignoreLocation(stmt))
        return true;
    MarkIfAssignment(stmt->getBody());
    return true;
}

bool BuriedAssign::VisitLabelStmt(LabelStmt const* stmt)
{
    if (ignoreLocation(stmt))
        return true;
    MarkIfAssignment(stmt->getSubStmt());
    return true;
}

bool BuriedAssign::VisitVarDecl(VarDecl const* stmt)
{
    if (ignoreLocation(stmt))
        return true;
    if (stmt->getInit())
    {
        auto expr = IgnoreImplicitAndConversionOperator(stmt->getInit());
        MarkIfAssignment(expr);
        if (auto cxxConstruct = dyn_cast<CXXConstructExpr>(expr))
        {
            if (cxxConstruct->getNumArgs() == 1)
                MarkIfAssignment(cxxConstruct->getArg(0));
        }
    }
    return true;
}

bool BuriedAssign::VisitCXXFoldExpr(CXXFoldExpr const* stmt)
{
    if (ignoreLocation(stmt))
        return true;
    MarkConditionForControlLoops(stmt->getLHS());
    MarkConditionForControlLoops(stmt->getRHS());
    return true;
}

// off by default because it uses getParentStmt so it's more expensive to run
loplugin::Plugin::Registration<BuriedAssign> X("buriedassign", false);
}

/* vim:set shiftwidth=4 softtabstop=4 expandtab: */