compilerplugins/clang/buriedassign.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  */
   9
  10 #include <cassert>
  11 #include <string>
  12 #include <iostream>
  13 #include <unordered_set>
  14
  15 #include "plugin.hxx"
  16 #include "check.hxx"
  17 #include "config_clang.h"
  18 #include "clang/AST/CXXInheritance.h"
  19 #include "clang/AST/StmtVisitor.h"
  20
  21 // This checker aims to pull buried assignments out of complex expressions,
  22 // where they are quite hard to notice amidst the other conditional logic.
  23
  24 namespace
  25 {
  26 class BuriedAssign : public loplugin::FilteringPlugin<BuriedAssign>
  27 {
  28 public:
  29     explicit BuriedAssign(loplugin::InstantiationData const& data)
  30         : FilteringPlugin(data)
  31     {
  32     }
  33
  34     virtual void run() override
  35     {
  36         std::string fn(handler.getMainFileName());
  37         loplugin::normalizeDotDotInFilePath(fn);
  38
  39         // code where I don't have a better alternative
  40         if (fn == SRCDIR "/sal/osl/unx/profile.cxx")
  41             return;
  42         if (fn == SRCDIR "/sal/rtl/uri.cxx")
  43             return;
  44         if (fn == SRCDIR "/sal/osl/unx/process.cxx")
  45             return;
  46         if (fn == SRCDIR "/sal/rtl/bootstrap.cxx")
  47             return;
  48         if (fn == SRCDIR "/i18npool/source/textconversion/genconv_dict.cxx")
  49             return;
  50         if (fn == SRCDIR "/soltools/cpp/_macro.c")
  51             return;
  52         if (fn == SRCDIR "/stoc/source/inspect/introspection.cxx")
  53             return;
  54         if (fn == SRCDIR "/tools/source/fsys/urlobj.cxx")
  55             return;
  56         if (fn == SRCDIR "/sax/source/tools/fastserializer.cxx")
  57             return;
  58         if (fn == SRCDIR "/svl/source/crypto/cryptosign.cxx")
  59             return;
  60         if (fn == SRCDIR "/svl/source/numbers/zforfind.cxx")
  61             return;
  62         if (fn == SRCDIR "/svl/source/numbers/zformat.cxx")
  63             return;
  64         if (fn == SRCDIR "/svl/source/numbers/zforscan.cxx")
  65             return;
  66         if (fn == SRCDIR "/svl/source/numbers/zforlist.cxx")
  67             return;
  68         if (fn == SRCDIR "/vcl/source/window/debugevent.cxx")
  69             return;
  70         if (fn == SRCDIR "/vcl/source/control/scrbar.cxx")
  71             return;
  72         if (fn == SRCDIR "/vcl/source/gdi/bitmap3.cxx")
  73             return;
  74         if (fn == SRCDIR "/vcl/source/window/menu.cxx")
  75             return;
  76         if (fn == SRCDIR "/vcl/source/fontsubset/sft.cxx")
  77             return;
  78         if (fn == SRCDIR "/vcl/unx/generic/print/prtsetup.cxx")
  79             return;
  80         if (fn == SRCDIR "/svtools/source/brwbox/brwbox1.cxx")
  81             return;
  82         if (fn == SRCDIR "/svtools/source/control/valueset.cxx")
  83             return;
  84         if (fn == SRCDIR "/basic/source/runtime/iosys.cxx")
  85             return;
  86         if (fn == SRCDIR "/basic/source/runtime/runtime.cxx")
  87             return;
  88         if (fn == SRCDIR "/basic/source/sbx/sbxvalue.cxx")
  89             return;
  90         if (fn == SRCDIR "/basic/source/sbx/sbxvalue.cxx")
  91             return;
  92         if (fn == SRCDIR "/sfx2/source/dialog/templdlg.cxx")
  93             return;
  94         if (fn == SRCDIR "/sfx2/source/view/viewfrm.cxx")
  95             return;
  96         if (fn == SRCDIR "/connectivity/source/commontools/dbtools.cxx")
  97             return;
  98         if (fn == SRCDIR "/xmloff/source/style/xmlnumfi.cxx")
  99             return;
 100         if (fn == SRCDIR "/xmloff/source/style/xmlnumfe .cxx")
 101             return;
 102         if (fn == SRCDIR "/editeng/source/items/textitem.cxx")
 103             return;
 104         if (fn == SRCDIR "/editeng/source/rtf/rtfitem.cxx")
 105             return;
 106         if (fn == SRCDIR "/editeng/source/rtf/svxrtf.cxx")
 107             return;
 108         if (fn == SRCDIR "/editeng/source/misc/svxacorr.cxx")
 109             return;
 110         if (fn == SRCDIR "/svx/source/items/numfmtsh.cxx")
 111             return;
 112         if (fn == SRCDIR "/svx/source/dialog/hdft.cxx")
 113             return;
 114         if (fn == SRCDIR "/cui/source/dialogs/insdlg.cxx")
 115             return;
 116         if (fn == SRCDIR "/cui/source/tabpages/paragrph.cxx")
 117             return;
 118         if (fn == SRCDIR "/cui/source/tabpages/page.cxx")
 119             return;
 120         if (fn == SRCDIR "/cui/source/tabpages/border.cxx")
 121             return;
 122         if (fn == SRCDIR "/cui/source/tabpages/chardlg.cxx")
 123             return;
 124         if (fn == SRCDIR "/cui/source/tabpages/numpages.cxx")
 125             return;
 126         if (fn == SRCDIR "/cui/source/dialogs/SpellDialog.cxx")
 127             return;
 128         if (fn == SRCDIR "/oox/source/drawingml/diagram/diagramlayoutatoms.cxx")
 129             return;
 130         if (fn == SRCDIR "/dbaccess/source/core/dataaccess/intercept.cxx")
 131             return;
 132         if (fn == SRCDIR "/sw/writerfilter/dmapper/DomainMapper.cxx")
 133             return;
 134         if (fn == SRCDIR "/sw/writerfilter/dmapper/DomainMapper_Impl.cxx")
 135             return;
 136         if (fn == SRCDIR "/lotuswordpro/source/filter/lwptablelayout.cxx")
 137             return;
 138         if (fn == SRCDIR "/i18npool/source/characterclassification/cclass_unicode_parser.cxx")
 139             return;
 140         if (fn == SRCDIR "/sd/source/filter/eppt/pptx-animations.cxx")
 141             return;
 142         if (fn == SRCDIR "/sc/source/core/tool/address.cxx")
 143             return;
 144         if (fn == SRCDIR "/sc/source/core/tool/interpr1.cxx")
 145             return;
 146         if (fn == SRCDIR "/sc/source/core/tool/interpr4.cxx")
 147             return;
 148         if (fn == SRCDIR "/sc/source/core/tool/interpr5.cxx")
 149             return;
 150         if (fn == SRCDIR "/sc/source/core/tool/compiler.cxx")
 151             return;
 152         if (fn == SRCDIR "/sc/source/core/data/table4.cxx")
 153             return;
 154         if (fn == SRCDIR "/sc/source/ui/drawfunc/fudraw.cxx")
 155             return;
 156         if (fn == SRCDIR "/sc/source/filter/xml/xmlcelli.cxx")
 157             return;
 158         if (fn == SRCDIR "/sc/source/ui/miscdlgs/crnrdlg.cxx")
 159             return;
 160         if (fn == SRCDIR "/sc/source/ui/app/inputwin.cxx")
 161             return;
 162         if (fn == SRCDIR "/sc/source/ui/view/viewfun2.cxx")
 163             return;
 164         if (fn == SRCDIR "/sc/source/ui/unoobj/docuno.cxx")
 165             return;
 166         if (fn == SRCDIR "/sc/source/ui/view/gridwin.cxx")
 167             return;
 168         if (fn == SRCDIR "/sw/source/core/crsr/callnk.cxx")
 169             return;
 170         if (fn == SRCDIR "/sw/source/core/crsr/findtxt.cxx")
 171             return;
 172         if (fn == SRCDIR "/sw/source/core/crsr/crsrsh.cxx")
 173             return;
 174         if (fn == SRCDIR "/sw/source/core/crsr/crstrvl.cxx")
 175             return;
 176         if (fn == SRCDIR "/sw/source/core/doc/doccomp.cxx")
 177             return;
 178         if (fn == SRCDIR "/sw/source/core/doc/docedt.cxx")
 179             return;
 180         if (fn == SRCDIR "/sw/source/core/doc/docfly.cxx")
 181             return;
 182         if (fn == SRCDIR "/sw/source/core/doc/DocumentRedlineManager.cxx")
 183             return;
 184         if (fn == SRCDIR "/sw/source/core/doc/notxtfrm.cxx")
 185             return;
 186         if (fn == SRCDIR "/sw/source/core/docnode/node.cxx")
 187             return;
 188         if (fn == SRCDIR "/sw/source/core/layout/ftnfrm.cxx")
 189             return;
 190         if (fn == SRCDIR "/sw/source/core/table/swtable.cxx")
 191             return;
 192         if (fn == SRCDIR "/sw/source/core/unocore/unoframe.cxx")
 193             return;
 194         if (fn == SRCDIR "/sw/source/filter/xml/xmlimp.cxx")
 195             return;
 196         if (fn == SRCDIR "/sw/source/uibase/docvw/edtwin.cxx")
 197             return;
 198         if (fn == SRCDIR "/sw/source/uibase/shells/langhelper.cxx")
 199             return;
 200         if (fn == SRCDIR "/sw/source/uibase/shells/tabsh.cxx")
 201             return;
 202         if (fn == SRCDIR "/sw/source/uibase/shells/textsh1.cxx")
 203             return;
 204         if (fn == SRCDIR "/sw/source/uibase/uiview/view2.cxx")
 205             return;
 206         if (fn == SRCDIR "/starmath/source/mathtype.cxx")
 207             return;
 208         if (fn == SRCDIR "/starmath/source/mathmlexport.cxx")
 209             return;
 210         if (fn == SRCDIR "/starmath/source/view.cxx")
 211             return;
 212         if (fn == SRCDIR "/xmlhelp/source/treeview/tvread.cxx")
 213             return;
 214         TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
 215     }
 216
 217     bool VisitBinaryOperator(BinaryOperator const*);
 218     bool VisitCXXOperatorCallExpr(CXXOperatorCallExpr const*);
 219     bool VisitCompoundStmt(CompoundStmt const*);
 220     bool VisitIfStmt(IfStmt const*);
 221     bool VisitLabelStmt(LabelStmt const*);
 222     bool VisitForStmt(ForStmt const*);
 223     bool VisitCXXForRangeStmt(CXXForRangeStmt const*);
 224     bool VisitWhileStmt(WhileStmt const*);
 225     bool VisitDoStmt(DoStmt const*);
 226     bool VisitCaseStmt(CaseStmt const*);
 227     bool VisitDefaultStmt(DefaultStmt const*);
 228     bool VisitVarDecl(VarDecl const*);
 229     bool VisitCXXFoldExpr(CXXFoldExpr const*);
 230
 231 private:
 232     void MarkIfAssignment(Stmt const*);
 233     void MarkAll(Stmt const*);
 234     void MarkConditionForControlLoops(Expr const*);
 235
 236     std::unordered_set<const Stmt*> m_handled;
 237 };
 238
 239 static bool isAssignmentOp(clang::BinaryOperatorKind op)
 240 {
 241     // We ignore BO_ShrAssign i.e. >>= because we use that everywhere for
 242     // extracting data from css::uno::Any
 243     return op == BO_Assign || op == BO_MulAssign || op == BO_DivAssign || op == BO_RemAssign
 244            || op == BO_AddAssign || op == BO_SubAssign || op == BO_ShlAssign || op == BO_AndAssign
 245            || op == BO_XorAssign || op == BO_OrAssign;
 246 }
 247
 248 static bool isAssignmentOp(clang::OverloadedOperatorKind Opc)
 249 {
 250     // Same logic as CXXOperatorCallExpr::isAssignmentOp(), which our supported clang
 251     // doesn't have yet.
 252     // Except that we ignore OO_GreaterGreaterEqual i.e. >>= because we use that everywhere for
 253     // extracting data from css::uno::Any
 254     return Opc == OO_Equal || Opc == OO_StarEqual || Opc == OO_SlashEqual || Opc == OO_PercentEqual
 255            || Opc == OO_PlusEqual || Opc == OO_MinusEqual || Opc == OO_LessLessEqual
 256            || Opc == OO_AmpEqual || Opc == OO_CaretEqual || Opc == OO_PipeEqual;
 257 }
 258
 259 static const Expr* IgnoreImplicitAndConversionOperator(const Expr* expr)
 260 {
 261     expr = expr->IgnoreImplicit();
 262     if (auto memberCall = dyn_cast<CXXMemberCallExpr>(expr))
 263     {
 264         if (auto conversionDecl = dyn_cast_or_null<CXXConversionDecl>(memberCall->getMethodDecl()))
 265         {
 266             if (!conversionDecl->isExplicit())
 267                 expr = memberCall->getImplicitObjectArgument()->IgnoreImplicit();
 268         }
 269     }
 270     return expr;
 271 }
 272
 273 bool BuriedAssign::VisitBinaryOperator(BinaryOperator const* binaryOp)
 274 {
 275     if (ignoreLocation(binaryOp))
 276         return true;
 277     if (binaryOp->getBeginLoc().isMacroID())
 278         return true;
 279     if (!isAssignmentOp(binaryOp->getOpcode()))
 280         return true;
 281     auto expr = IgnoreImplicitAndConversionOperator(binaryOp->getRHS());
 282     if (auto rhs = dyn_cast<BinaryOperator>(expr))
 283     {
 284         // Ignore chained assignment.
 285         // TODO limit this to only ordinary assignment
 286         if (isAssignmentOp(rhs->getOpcode()))
 287             m_handled.insert(rhs);
 288     }
 289     else if (auto rhs = dyn_cast<CXXOperatorCallExpr>(expr))
 290     {
 291         // Ignore chained assignment.
 292         // TODO limit this to only ordinary assignment
 293         if (isAssignmentOp(rhs->getOperator()))
 294             m_handled.insert(rhs);
 295     }
 296     else if (auto cxxConstruct = dyn_cast<CXXConstructExpr>(expr))
 297     {
 298         if (cxxConstruct->getNumArgs() == 1)
 299             MarkIfAssignment(cxxConstruct->getArg(0));
 300     }
 301     if (!m_handled.insert(binaryOp).second)
 302         return true;
 303
 304     // assignment in constructor
 305     StringRef aFileName = getFilenameOfLocation(
 306         compiler.getSourceManager().getSpellingLoc(binaryOp->getBeginLoc()));
 307     if (loplugin::hasPathnamePrefix(aFileName, SRCDIR "/include/comphelper/flagguard.hxx"))
 308         return true;
 309
 310     report(DiagnosticsEngine::Warning, "buried assignment, rather put on own line",
 311            binaryOp->getBeginLoc())
 312         << binaryOp->getSourceRange();
 313     //getParentStmt(getParentStmt(getParentStmt(getParentStmt(getParentStmt(getParentStmt(binaryOp))))))->dump();
 314     return true;
 315 }
 316
 317 bool BuriedAssign::VisitCXXOperatorCallExpr(CXXOperatorCallExpr const* cxxOper)
 318 {
 319     if (ignoreLocation(cxxOper))
 320         return true;
 321     if (cxxOper->getBeginLoc().isMacroID())
 322         return true;
 323     if (!isAssignmentOp(cxxOper->getOperator()))
 324         return true;
 325     auto expr = IgnoreImplicitAndConversionOperator(cxxOper->getArg(1));
 326     if (auto rhs = dyn_cast<BinaryOperator>(expr))
 327     {
 328         // Ignore chained assignment.
 329         // TODO limit this to only ordinary assignment
 330         if (isAssignmentOp(rhs->getOpcode()))
 331             m_handled.insert(rhs);
 332     }
 333     else if (auto rhs = dyn_cast<CXXOperatorCallExpr>(expr))
 334     {
 335         // Ignore chained assignment.
 336         // TODO limit this to only ordinary assignment
 337         if (isAssignmentOp(rhs->getOperator()))
 338             m_handled.insert(rhs);
 339     }
 340     else if (auto cxxConstruct = dyn_cast<CXXConstructExpr>(expr))
 341     {
 342         if (cxxConstruct->getNumArgs() == 1)
 343             MarkIfAssignment(cxxConstruct->getArg(0));
 344     }
 345     if (!m_handled.insert(cxxOper).second)
 346         return true;
 347     report(DiagnosticsEngine::Warning, "buried assignment, rather put on own line",
 348            cxxOper->getBeginLoc())
 349         << cxxOper->getSourceRange();
 350     //getParentStmt(getParentStmt(getParentStmt(getParentStmt(getParentStmt(cxxOper)))))->dump();
 351     return true;
 352 }
 353
 354 bool BuriedAssign::VisitCompoundStmt(CompoundStmt const* compoundStmt)
 355 {
 356     if (ignoreLocation(compoundStmt))
 357         return true;
 358     for (auto i = compoundStmt->child_begin(); i != compoundStmt->child_end(); ++i)
 359     {
 360         if (auto expr = dyn_cast<Expr>(*i))
 361         {
 362             expr = expr->IgnoreImplicit();
 363             if (auto binaryOp = dyn_cast<BinaryOperator>(expr))
 364             {
 365                 // ignore comma-chained statements at this level
 366                 if (binaryOp->getOpcode() == BO_Comma)
 367                 {
 368                     MarkIfAssignment(binaryOp->getLHS());
 369                     MarkIfAssignment(binaryOp->getRHS());
 370                     continue;
 371                 }
 372             }
 373             MarkIfAssignment(expr);
 374         }
 375     }
 376     return true;
 377 }
 378
 379 void BuriedAssign::MarkIfAssignment(Stmt const* stmt)
 380 {
 381     if (auto expr = dyn_cast_or_null<Expr>(stmt))
 382     {
 383         expr = expr->IgnoreImplicit();
 384         if (auto binaryOp = dyn_cast<BinaryOperator>(expr))
 385         {
 386             if (isAssignmentOp(binaryOp->getOpcode()))
 387             {
 388                 m_handled.insert(expr);
 389                 MarkIfAssignment(binaryOp->getRHS()); // in case it is chained
 390             }
 391             else if (binaryOp->getOpcode() == BO_Comma)
 392             {
 393                 MarkIfAssignment(binaryOp->getLHS());
 394                 MarkIfAssignment(binaryOp->getRHS());
 395             }
 396         }
 397         else if (auto cxxOper = dyn_cast<CXXOperatorCallExpr>(expr))
 398         {
 399             if (isAssignmentOp(cxxOper->getOperator()))
 400             {
 401                 m_handled.insert(expr);
 402                 MarkIfAssignment(cxxOper->getArg(1)); // in case it is chained
 403             }
 404         }
 405     }
 406 }
 407
 408 void BuriedAssign::MarkAll(Stmt const* stmt)
 409 {
 410     m_handled.insert(stmt);
 411     for (auto it = stmt->child_begin(); it != stmt->child_end(); ++it)
 412         MarkAll(*it);
 413 }
 414
 415 /**
 416  * Restrict this to cases where the buried assignment is part of the first
 417  * condition inside the if condition. Other cases tend to be too hard
 418  * too extract (notably in sw/)
 419  */
 420 bool BuriedAssign::VisitIfStmt(IfStmt const* ifStmt)
 421 {
 422     if (ignoreLocation(ifStmt))
 423         return true;
 424     MarkIfAssignment(ifStmt->getThen());
 425     MarkIfAssignment(ifStmt->getElse());
 426
 427     auto expr = ifStmt->getCond();
 428     expr = IgnoreImplicitAndConversionOperator(expr);
 429     expr = expr->IgnoreParens();
 430     expr = IgnoreImplicitAndConversionOperator(expr);
 431     MarkAll(expr);
 432
 433     if (auto binaryOp = dyn_cast<BinaryOperator>(expr))
 434     {
 435         if (isAssignmentOp(binaryOp->getOpcode()))
 436         {
 437             report(DiagnosticsEngine::Warning, "buried assignment, rather put on own line",
 438                    expr->getBeginLoc())
 439                 << expr->getSourceRange();
 440         }
 441         else if (binaryOp->isComparisonOp())
 442         {
 443             if (auto binaryOp2
 444                 = dyn_cast<BinaryOperator>(binaryOp->getLHS()->IgnoreParenImpCasts()))
 445             {
 446                 if (!binaryOp->getRHS()->isValueDependent()
 447                     && binaryOp->getRHS()->isCXX11ConstantExpr(compiler.getASTContext())
 448                     && isAssignmentOp(binaryOp2->getOpcode()))
 449                     report(DiagnosticsEngine::Warning, "buried assignment, rather put on own line",
 450                            expr->getBeginLoc())
 451                         << expr->getSourceRange();
 452             }
 453             if (auto binaryOp2
 454                 = dyn_cast<BinaryOperator>(binaryOp->getRHS()->IgnoreParenImpCasts()))
 455             {
 456                 if (!binaryOp->getLHS()->isValueDependent()
 457                     && binaryOp->getLHS()->isCXX11ConstantExpr(compiler.getASTContext())
 458                     && isAssignmentOp(binaryOp2->getOpcode()))
 459                     report(DiagnosticsEngine::Warning, "buried assignment, rather put on own line",
 460                            expr->getBeginLoc())
 461                         << expr->getSourceRange();
 462             }
 463         }
 464         else if (binaryOp->isLogicalOp())
 465         {
 466             if (auto binaryOp2
 467                 = dyn_cast<BinaryOperator>(binaryOp->getLHS()->IgnoreParenImpCasts()))
 468             {
 469                 if (isAssignmentOp(binaryOp2->getOpcode()))
 470                     report(DiagnosticsEngine::Warning, "buried assignment, rather put on own line",
 471                            expr->getBeginLoc())
 472                         << expr->getSourceRange();
 473             }
 474         }
 475     }
 476     else if (auto operCall = dyn_cast<CXXOperatorCallExpr>(expr))
 477     {
 478         // Ignore chained assignment.
 479         // TODO limit this to only ordinary assignment
 480         if (isAssignmentOp(operCall->getOperator()))
 481         {
 482             report(DiagnosticsEngine::Warning, "buried assignment, rather put on own line",
 483                    expr->getBeginLoc())
 484                 << expr->getSourceRange();
 485         }
 486     }
 487
 488     return true;
 489 }
 490
 491 bool BuriedAssign::VisitCaseStmt(CaseStmt const* stmt)
 492 {
 493     if (ignoreLocation(stmt))
 494         return true;
 495     MarkIfAssignment(stmt->getSubStmt());
 496     return true;
 497 }
 498
 499 bool BuriedAssign::VisitDefaultStmt(DefaultStmt const* stmt)
 500 {
 501     if (ignoreLocation(stmt))
 502         return true;
 503     MarkIfAssignment(stmt->getSubStmt());
 504     return true;
 505 }
 506
 507 bool BuriedAssign::VisitWhileStmt(WhileStmt const* stmt)
 508 {
 509     if (ignoreLocation(stmt))
 510         return true;
 511     MarkConditionForControlLoops(stmt->getCond());
 512     MarkIfAssignment(stmt->getBody());
 513     return true;
 514 }
 515
 516 bool BuriedAssign::VisitDoStmt(DoStmt const* stmt)
 517 {
 518     if (ignoreLocation(stmt))
 519         return true;
 520     MarkConditionForControlLoops(stmt->getCond());
 521     MarkIfAssignment(stmt->getBody());
 522     return true;
 523 }
 524
 525 /** stuff like
 526  *    while ((x = foo())
 527  * and
 528  *    while ((x = foo() < 0)
 529  * is considered idiomatic.
 530  */
 531 void BuriedAssign::MarkConditionForControlLoops(Expr const* expr)
 532 {
 533     if (!expr)
 534         return;
 535     expr = expr->IgnoreImplicit();
 536
 537     if (auto binaryOp = dyn_cast<BinaryOperator>(expr))
 538     {
 539         // ignore comma-chained statements at this level
 540         if (binaryOp->getOpcode() == BO_Comma)
 541         {
 542             MarkConditionForControlLoops(binaryOp->getLHS());
 543             MarkConditionForControlLoops(binaryOp->getRHS());
 544             return;
 545         }
 546     }
 547
 548     // unwrap conversion to bool
 549     if (auto memberCall = dyn_cast<CXXMemberCallExpr>(expr))
 550     {
 551         if (memberCall->getMethodDecl() && isa<CXXConversionDecl>(memberCall->getMethodDecl()))
 552         {
 553             // TODO check that the conversion is converting to bool
 554             expr = memberCall->getImplicitObjectArgument()->IgnoreImplicit();
 555         }
 556     }
 557
 558     if (auto binaryOp = dyn_cast<BinaryOperator>(expr))
 559     {
 560         // handle: ((xxx = foo()) != error)
 561         if (binaryOp->isComparisonOp())
 562         {
 563             MarkIfAssignment(binaryOp->getLHS()->IgnoreImplicit()->IgnoreParens());
 564             MarkIfAssignment(binaryOp->getRHS()->IgnoreImplicit()->IgnoreParens());
 565         }
 566     }
 567     else if (auto cxxOper = dyn_cast<CXXOperatorCallExpr>(expr))
 568     {
 569         // handle: ((xxx = foo()) != error)
 570         if (cxxOper->isComparisonOp())
 571         {
 572             MarkIfAssignment(cxxOper->getArg(0)->IgnoreImplicit()->IgnoreParens());
 573             MarkIfAssignment(cxxOper->getArg(1)->IgnoreImplicit()->IgnoreParens());
 574         }
 575         // handle: (!(xxx = foo()))
 576         else if (cxxOper->getOperator() == OO_Exclaim)
 577             MarkIfAssignment(cxxOper->getArg(0)->IgnoreImplicit()->IgnoreParens());
 578     }
 579     else if (auto parenExpr = dyn_cast<ParenExpr>(expr))
 580     {
 581         // handle: ((xxx = foo()))
 582         MarkIfAssignment(parenExpr->getSubExpr()->IgnoreImplicit());
 583     }
 584     else if (auto unaryOp = dyn_cast<UnaryOperator>(expr))
 585     {
 586         // handle: (!(xxx = foo()))
 587         MarkIfAssignment(unaryOp->getSubExpr()->IgnoreImplicit()->IgnoreParens());
 588     }
 589     else
 590         MarkIfAssignment(expr);
 591 }
 592
 593 bool BuriedAssign::VisitForStmt(ForStmt const* stmt)
 594 {
 595     if (ignoreLocation(stmt))
 596         return true;
 597     MarkIfAssignment(stmt->getInit());
 598     MarkConditionForControlLoops(stmt->getCond());
 599     MarkIfAssignment(stmt->getInc());
 600     MarkIfAssignment(stmt->getBody());
 601     return true;
 602 }
 603
 604 bool BuriedAssign::VisitCXXForRangeStmt(CXXForRangeStmt const* stmt)
 605 {
 606     if (ignoreLocation(stmt))
 607         return true;
 608     MarkIfAssignment(stmt->getBody());
 609     return true;
 610 }
 611
 612 bool BuriedAssign::VisitLabelStmt(LabelStmt const* stmt)
 613 {
 614     if (ignoreLocation(stmt))
 615         return true;
 616     MarkIfAssignment(stmt->getSubStmt());
 617     return true;
 618 }
 619
 620 bool BuriedAssign::VisitVarDecl(VarDecl const* stmt)
 621 {
 622     if (ignoreLocation(stmt))
 623         return true;
 624     if (stmt->getInit())
 625     {
 626         auto expr = IgnoreImplicitAndConversionOperator(stmt->getInit());
 627         MarkIfAssignment(expr);
 628         if (auto cxxConstruct = dyn_cast<CXXConstructExpr>(expr))
 629         {
 630             if (cxxConstruct->getNumArgs() == 1)
 631                 MarkIfAssignment(cxxConstruct->getArg(0));
 632         }
 633     }
 634     return true;
 635 }
 636
 637 bool BuriedAssign::VisitCXXFoldExpr(CXXFoldExpr const* stmt)
 638 {
 639     if (ignoreLocation(stmt))
 640         return true;
 641     MarkConditionForControlLoops(stmt->getLHS());
 642     MarkConditionForControlLoops(stmt->getRHS());
 643     return true;
 644 }
 645
 646 // off by default because it uses getParentStmt so it's more expensive to run
 647 loplugin::Plugin::Registration<BuriedAssign> X("buriedassign", false);
 648 }
 649
 650 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */