compilerplugins/clang/vclwidgets.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 <memory>
  11 #include <string>
  12 #include <iostream>
  13
  14 #include "plugin.hxx"
  15 #include "check.hxx"
  16 #include "clang/AST/CXXInheritance.h"
  17
  18 // Final goal: Checker for VCL widget references. Makes sure that VCL Window subclasses are properly referenced counted and dispose()'ed.
  19 //
  20 // But at the moment it just finds subclasses of Window which are not heap-allocated
  21 //
  22 // TODO do I need to check for local and static variables, too ?
  23 // TODO when we have a dispose() method, verify that the dispose() methods releases all of the Window references
  24 // TODO when we have a dispose() method, verify that it calls the super-class dispose() method at some point.
  25
  26 namespace {
  27
  28 class VCLWidgets:
  29     public RecursiveASTVisitor<VCLWidgets>, public loplugin::Plugin
  30 {
  31 public:
  32     explicit VCLWidgets(loplugin::InstantiationData const & data): Plugin(data)
  33     {}
  34
  35     virtual void run() override { TraverseDecl(compiler.getASTContext().getTranslationUnitDecl()); }
  36
  37     bool shouldVisitTemplateInstantiations () const { return true; }
  38
  39     bool VisitVarDecl(const VarDecl *);
  40     bool VisitFieldDecl(const FieldDecl *);
  41     bool VisitParmVarDecl(const ParmVarDecl *);
  42     bool VisitFunctionDecl(const FunctionDecl *);
  43     bool VisitCXXDestructorDecl(const CXXDestructorDecl *);
  44     bool VisitCXXDeleteExpr(const CXXDeleteExpr *);
  45     bool VisitCallExpr(const CallExpr *);
  46     bool VisitDeclRefExpr(const DeclRefExpr *);
  47     bool VisitCXXConstructExpr(const CXXConstructExpr *);
  48     bool VisitBinaryOperator(const BinaryOperator *);
  49 private:
  50     void checkAssignmentForVclPtrToRawConversion(const SourceLocation& sourceLoc, const clang::Type* lhsType, const Expr* rhs);
  51     bool isDisposeCallingSuperclassDispose(const CXXMethodDecl* pMethodDecl);
  52     bool mbCheckingMemcpy = false;
  53 };
  54
  55 #define BASE_REF_COUNTED_CLASS "VclReferenceBase"
  56
  57 bool BaseCheckNotWindowSubclass(const CXXRecordDecl *BaseDefinition) {
  58     return !loplugin::DeclCheck(BaseDefinition).Class(BASE_REF_COUNTED_CLASS)
  59         .GlobalNamespace();
  60 }
  61
  62 bool isDerivedFromVclReferenceBase(const CXXRecordDecl *decl) {
  63     if (!decl)
  64         return false;
  65     if (loplugin::DeclCheck(decl).Class(BASE_REF_COUNTED_CLASS)
  66         .GlobalNamespace())
  67     {
  68         return true;
  69     }
  70     if (!decl->hasDefinition()) {
  71         return false;
  72     }
  73     if (// not sure what hasAnyDependentBases() does,
  74         // but it avoids classes we don't want, e.g. WeakAggComponentImplHelper1
  75         !decl->hasAnyDependentBases() &&
  76         !decl->forallBases(BaseCheckNotWindowSubclass, true)) {
  77         return true;
  78     }
  79     return false;
  80 }
  81
  82 bool containsVclReferenceBaseSubclass(const clang::Type* pType0);
  83
  84 bool containsVclReferenceBaseSubclass(const QualType& qType) {
  85     auto check = loplugin::TypeCheck(qType);
  86     if (check.Class("ScopedVclPtr").GlobalNamespace()
  87         || check.Class("ScopedVclPtrInstance").GlobalNamespace()
  88         || check.Class("VclPtr").GlobalNamespace()
  89         || check.Class("VclPtrInstance").GlobalNamespace())
  90     {
  91         return false;
  92     }
  93     return containsVclReferenceBaseSubclass(qType.getTypePtr());
  94 }
  95
  96 bool containsVclReferenceBaseSubclass(const clang::Type* pType0) {
  97     if (!pType0)
  98         return false;
  99     const clang::Type* pType = pType0->getUnqualifiedDesugaredType();
 100     if (!pType)
 101         return false;
 102     const CXXRecordDecl* pRecordDecl = pType->getAsCXXRecordDecl();
 103     if (pRecordDecl) {
 104         const ClassTemplateSpecializationDecl* pTemplate = dyn_cast<ClassTemplateSpecializationDecl>(pRecordDecl);
 105         if (pTemplate) {
 106             auto check = loplugin::DeclCheck(pTemplate);
 107             if (check.Class("VclStatusListener").GlobalNamespace()) {
 108                 return false;
 109             }
 110             bool link = bool(check.Class("Link").GlobalNamespace());
 111             for(unsigned i=0; i<pTemplate->getTemplateArgs().size(); ++i) {
 112                 const TemplateArgument& rArg = pTemplate->getTemplateArgs()[i];
 113                 if (rArg.getKind() == TemplateArgument::ArgKind::Type &&
 114                     containsVclReferenceBaseSubclass(rArg.getAsType()))
 115                 {
 116                     // OK for first template argument of tools/link.hxx Link
 117                     // to be a Window-derived pointer:
 118                     if (!link || i != 0) {
 119                         return true;
 120                     }
 121                 }
 122             }
 123         }
 124     }
 125     if (pType->isPointerType()) {
 126         QualType pointeeType = pType->getPointeeType();
 127         return containsVclReferenceBaseSubclass(pointeeType);
 128     } else if (pType->isArrayType()) {
 129         const clang::ArrayType* pArrayType = dyn_cast<clang::ArrayType>(pType);
 130         QualType elementType = pArrayType->getElementType();
 131         return containsVclReferenceBaseSubclass(elementType);
 132     } else {
 133         return isDerivedFromVclReferenceBase(pRecordDecl);
 134     }
 135 }
 136
 137 bool VCLWidgets::VisitCXXDestructorDecl(const CXXDestructorDecl* pCXXDestructorDecl)
 138 {
 139     if (ignoreLocation(pCXXDestructorDecl)) {
 140         return true;
 141     }
 142     if (!pCXXDestructorDecl->isThisDeclarationADefinition()) {
 143         return true;
 144     }
 145     const CXXRecordDecl * pRecordDecl = pCXXDestructorDecl->getParent();
 146     // ignore
 147     if (loplugin::DeclCheck(pRecordDecl).Class(BASE_REF_COUNTED_CLASS)
 148         .GlobalNamespace())
 149     {
 150         return true;
 151     }
 152     // check if this class is derived from VclReferenceBase
 153     if (!isDerivedFromVclReferenceBase(pRecordDecl)) {
 154         return true;
 155     }
 156     // check if we have any VclPtr<> fields
 157     bool bFoundVclPtrField = false;
 158     for(auto fieldDecl = pRecordDecl->field_begin();
 159         fieldDecl != pRecordDecl->field_end(); ++fieldDecl)
 160     {
 161         const RecordType *pFieldRecordType = fieldDecl->getType()->getAs<RecordType>();
 162         if (pFieldRecordType) {
 163             if (loplugin::DeclCheck(pFieldRecordType->getDecl())
 164                 .Class("VclPtr").GlobalNamespace())
 165             {
 166                bFoundVclPtrField = true;
 167                break;
 168             }
 169        }
 170     }
 171     // check if there is a dispose() method
 172     bool bFoundDispose = false;
 173     for(auto methodDecl = pRecordDecl->method_begin();
 174         methodDecl != pRecordDecl->method_end(); ++methodDecl)
 175     {
 176         if (methodDecl->isInstance() && methodDecl->param_size()==0
 177             && loplugin::DeclCheck(*methodDecl).Function("dispose"))
 178         {
 179            bFoundDispose = true;
 180            break;
 181         }
 182     }
 183     const CompoundStmt *pCompoundStatement = dyn_cast_or_null<CompoundStmt>(pCXXDestructorDecl->getBody());
 184     // having an empty body and no dispose() method is fine
 185     if (!bFoundVclPtrField && !bFoundDispose && (!pCompoundStatement || pCompoundStatement->size() == 0)) {
 186         return true;
 187     }
 188     if (bFoundVclPtrField && (!pCompoundStatement || pCompoundStatement->size() == 0)) {
 189         report(
 190             DiagnosticsEngine::Warning,
 191             BASE_REF_COUNTED_CLASS " subclass with VclPtr field must call disposeOnce() from its destructor",
 192             pCXXDestructorDecl->getLocStart())
 193           << pCXXDestructorDecl->getSourceRange();
 194         return true;
 195     }
 196     // Check that the destructor for a BASE_REF_COUNTED_CLASS subclass either
 197     // only calls disposeOnce() or, if !bFoundVclPtrField, does nothing at all:
 198     bool bOk = false;
 199     if (pCompoundStatement) {
 200         bool bFoundDisposeOnce = false;
 201         int nNumExtraStatements = 0;
 202         for (auto i = pCompoundStatement->body_begin();
 203              i != pCompoundStatement->body_end(); ++i)
 204         {
 205             //TODO: The below erroneously also skips past entire statements like
 206             //
 207             //  assert(true), ...;
 208             //
 209             auto skip = false;
 210             for (auto loc = (*i)->getLocStart();
 211                  compiler.getSourceManager().isMacroBodyExpansion(loc);
 212                  loc = compiler.getSourceManager().getImmediateMacroCallerLoc(
 213                      loc))
 214             {
 215                 auto const name = Lexer::getImmediateMacroName(
 216                     loc, compiler.getSourceManager(), compiler.getLangOpts());
 217                 if (name == "SAL_DEBUG" || name == "assert") {
 218                     skip = true;
 219                     break;
 220                 }
 221             }
 222             if (skip) {
 223                 continue;
 224             }
 225             if (auto const pCallExpr = dyn_cast<CXXMemberCallExpr>(*i)) {
 226                 if( const FunctionDecl* func = pCallExpr->getDirectCallee()) {
 227                     if( func->getNumParams() == 0 && func->getIdentifier() != NULL
 228                         && ( func->getName() == "disposeOnce" )) {
 229                         bFoundDisposeOnce = true;
 230                         continue;
 231                     }
 232                 }
 233             }
 234             nNumExtraStatements++;
 235         }
 236         bOk = (bFoundDisposeOnce || !bFoundVclPtrField)
 237             && nNumExtraStatements == 0;
 238     }
 239     if (!bOk) {
 240         SourceLocation spellingLocation = compiler.getSourceManager().getSpellingLoc(
 241                               pCXXDestructorDecl->getLocStart());
 242         StringRef filename = compiler.getSourceManager().getFilename(spellingLocation);
 243         if (   !(loplugin::isSamePathname(filename, SRCDIR "/vcl/source/window/window.cxx"))
 244             && !(loplugin::isSamePathname(filename, SRCDIR "/vcl/source/gdi/virdev.cxx"))
 245             && !(loplugin::isSamePathname(filename, SRCDIR "/vcl/qa/cppunit/lifecycle.cxx")) )
 246         {
 247             report(
 248                 DiagnosticsEngine::Warning,
 249                 BASE_REF_COUNTED_CLASS " subclass should have nothing in its destructor but a call to disposeOnce()",
 250                 pCXXDestructorDecl->getLocStart())
 251               << pCXXDestructorDecl->getSourceRange();
 252         }
 253     }
 254     return true;
 255 }
 256
 257 bool VCLWidgets::VisitBinaryOperator(const BinaryOperator * binaryOperator)
 258 {
 259     if (ignoreLocation(binaryOperator)) {
 260         return true;
 261     }
 262     if ( !binaryOperator->isAssignmentOp() ) {
 263         return true;
 264     }
 265     SourceLocation spellingLocation = compiler.getSourceManager().getSpellingLoc(
 266                           binaryOperator->getLocStart());
 267     checkAssignmentForVclPtrToRawConversion(spellingLocation, binaryOperator->getLHS()->getType().getTypePtr(), binaryOperator->getRHS());
 268     return true;
 269 }
 270
 271 // Look for places where we are accidentally assigning a returned-by-value VclPtr<T> to a T*, which generally
 272 // ends up in a use-after-free.
 273 void VCLWidgets::checkAssignmentForVclPtrToRawConversion(const SourceLocation& spellingLocation, const clang::Type* lhsType, const Expr* rhs)
 274 {
 275     if (!lhsType || !isa<clang::PointerType>(lhsType)) {
 276         return;
 277     }
 278     if (!rhs) {
 279         return;
 280     }
 281     StringRef filename = compiler.getSourceManager().getFilename(spellingLocation);
 282     if (loplugin::isSamePathname(filename, SRCDIR "/include/rtl/ref.hxx")) {
 283         return;
 284     }
 285     const CXXRecordDecl* pointeeClass = lhsType->getPointeeType()->getAsCXXRecordDecl();
 286     if (!isDerivedFromVclReferenceBase(pointeeClass)) {
 287         return;
 288     }
 289
 290     // if we have T* on the LHS and VclPtr<T> on the RHS, we expect to see either
 291     // an ImplicitCastExpr
 292     // or a ExprWithCleanups and then an ImplicitCastExpr
 293     if (auto implicitCastExpr = dyn_cast<ImplicitCastExpr>(rhs)) {
 294         if (implicitCastExpr->getCastKind() != CK_UserDefinedConversion) {
 295             return;
 296         }
 297         rhs = rhs->IgnoreCasts();
 298     } else if (auto exprWithCleanups = dyn_cast<ExprWithCleanups>(rhs)) {
 299         if (auto implicitCastExpr = dyn_cast<ImplicitCastExpr>(exprWithCleanups->getSubExpr())) {
 300             if (implicitCastExpr->getCastKind() != CK_UserDefinedConversion) {
 301                 return;
 302             }
 303             rhs = exprWithCleanups->IgnoreCasts();
 304         } else {
 305             return;
 306         }
 307     } else {
 308         return;
 309     }
 310     if (isa<CXXNullPtrLiteralExpr>(rhs)) {
 311         return;
 312     }
 313     if (isa<CXXThisExpr>(rhs)) {
 314         return;
 315     }
 316
 317     // ignore assignments from a member field to a local variable, to avoid unnecessary refcounting traffic
 318     if (auto callExpr = dyn_cast<CXXMemberCallExpr>(rhs)) {
 319         if (auto calleeMemberExpr = dyn_cast<MemberExpr>(callExpr->getCallee())) {
 320             if ((calleeMemberExpr = dyn_cast<MemberExpr>(calleeMemberExpr->getBase()->IgnoreImpCasts()))) {
 321                 if (isa<FieldDecl>(calleeMemberExpr->getMemberDecl())) {
 322                     return;
 323                 }
 324             }
 325         }
 326     }
 327
 328     // ignore assignments from a local variable to a local variable, to avoid unnecessary refcounting traffic
 329     if (auto callExpr = dyn_cast<CXXMemberCallExpr>(rhs)) {
 330         if (auto calleeMemberExpr = dyn_cast<MemberExpr>(callExpr->getCallee())) {
 331             if (auto declRefExpr = dyn_cast<DeclRefExpr>(calleeMemberExpr->getBase()->IgnoreImpCasts())) {
 332                 if (isa<VarDecl>(declRefExpr->getDecl())) {
 333                     return;
 334                 }
 335             }
 336         }
 337     }
 338     if (auto declRefExpr = dyn_cast<DeclRefExpr>(rhs->IgnoreImpCasts())) {
 339         if (isa<VarDecl>(declRefExpr->getDecl())) {
 340              return;
 341         }
 342     }
 343
 344     report(
 345         DiagnosticsEngine::Warning,
 346         "assigning a returned-by-value VclPtr<T> to a T* variable is dodgy, should be assigned to a VclPtr. If you know that the RHS does not return a newly created T, then add a '.get()' to the RHS",
 347          rhs->getSourceRange().getBegin())
 348         << rhs->getSourceRange();
 349 }
 350
 351 bool VCLWidgets::VisitVarDecl(const VarDecl * pVarDecl) {
 352     if (ignoreLocation(pVarDecl)) {
 353         return true;
 354     }
 355     if (isa<ParmVarDecl>(pVarDecl)) {
 356         return true;
 357     }
 358     SourceLocation spellingLocation = compiler.getSourceManager().getSpellingLoc(
 359                           pVarDecl->getLocStart());
 360     if (pVarDecl->getInit()) {
 361         checkAssignmentForVclPtrToRawConversion(spellingLocation, pVarDecl->getType().getTypePtr(), pVarDecl->getInit());
 362     }
 363     StringRef aFileName = compiler.getSourceManager().getFilename(spellingLocation);
 364     if (loplugin::isSamePathname(aFileName, SRCDIR "/include/vcl/vclptr.hxx"))
 365         return true;
 366     if (loplugin::isSamePathname(aFileName, SRCDIR "/vcl/source/window/layout.cxx"))
 367         return true;
 368     // whitelist the valid things that can contain pointers.
 369     // It is containing stuff like std::unique_ptr we get worried
 370     if (pVarDecl->getType()->isArrayType()) {
 371         return true;
 372     }
 373     auto tc = loplugin::TypeCheck(pVarDecl->getType());
 374     if (tc.Pointer()
 375         || tc.Class("map").StdNamespace()
 376         || tc.Class("multimap").StdNamespace()
 377         || tc.Class("vector").StdNamespace()
 378         || tc.Class("list").StdNamespace()
 379         || tc.Class("mem_fun1_t").StdNamespace()
 380           // registration template thing, doesn't actually allocate anything we need to care about
 381         || tc.Class("OMultiInstanceAutoRegistration").Namespace("compmodule").GlobalNamespace())
 382     {
 383         return true;
 384     }
 385     // Apparently I should be doing some kind of lookup for a partial specialisations of std::iterator_traits<T> to see if an
 386     // object is an iterator, but that sounds like too much work
 387     auto t = pVarDecl->getType().getDesugaredType(compiler.getASTContext());
 388     std::string s = t.getAsString();
 389     if (s.find("iterator") != std::string::npos
 390         || loplugin::TypeCheck(t).Class("__wrap_iter").StdNamespace())
 391     {
 392         return true;
 393     }
 394     // std::pair seems to show up in whacky ways in clang's AST. Sometimes it's a class, sometimes it's a typedef, and sometimes
 395     // its an ElaboratedType (whatever that is)
 396     if (s.find("pair") != std::string::npos) {
 397         return true;
 398     }
 399
 400     if (containsVclReferenceBaseSubclass(pVarDecl->getType())) {
 401         report(
 402             DiagnosticsEngine::Warning,
 403             BASE_REF_COUNTED_CLASS " subclass %0 should be wrapped in VclPtr",
 404             pVarDecl->getLocation())
 405             << pVarDecl->getType() << pVarDecl->getSourceRange();
 406         return true;
 407     }
 408     return true;
 409 }
 410
 411 bool VCLWidgets::VisitFieldDecl(const FieldDecl * fieldDecl) {
 412     if (ignoreLocation(fieldDecl)) {
 413         return true;
 414     }
 415     StringRef aFileName = compiler.getSourceManager().getFilename(compiler.getSourceManager().getSpellingLoc(fieldDecl->getLocStart()));
 416     if (loplugin::isSamePathname(aFileName, SRCDIR "/include/vcl/vclptr.hxx"))
 417         return true;
 418     if (loplugin::isSamePathname(aFileName, SRCDIR "/include/rtl/ref.hxx"))
 419         return true;
 420     if (loplugin::isSamePathname(aFileName, SRCDIR "/include/o3tl/enumarray.hxx"))
 421         return true;
 422     if (loplugin::isSamePathname(aFileName, SRCDIR "/vcl/source/window/layout.cxx"))
 423         return true;
 424     if (fieldDecl->isBitField()) {
 425         return true;
 426     }
 427     const CXXRecordDecl *pParentRecordDecl = isa<RecordDecl>(fieldDecl->getDeclContext()) ? dyn_cast<CXXRecordDecl>(fieldDecl->getParent()) : nullptr;
 428     if (loplugin::DeclCheck(pParentRecordDecl).Class("VclPtr")
 429         .GlobalNamespace())
 430     {
 431         return true;
 432     }
 433     if (containsVclReferenceBaseSubclass(fieldDecl->getType())) {
 434         // have to ignore this for now, nasty reverse dependency from tools->vcl
 435         auto check = loplugin::DeclCheck(pParentRecordDecl);
 436         if (!(check.Struct("ImplErrorContext").GlobalNamespace()
 437               || check.Class("ScHFEditPage").GlobalNamespace()))
 438         {
 439             report(
 440                 DiagnosticsEngine::Warning,
 441                 BASE_REF_COUNTED_CLASS " subclass %0 declared as a pointer member, should be wrapped in VclPtr",
 442                 fieldDecl->getLocation())
 443                 << fieldDecl->getType() << fieldDecl->getSourceRange();
 444             if (auto parent = dyn_cast<ClassTemplateSpecializationDecl>(fieldDecl->getParent())) {
 445                 report(
 446                     DiagnosticsEngine::Note,
 447                     "template field here",
 448                     parent->getPointOfInstantiation());
 449             }
 450             return true;
 451         }
 452     }
 453     const RecordType *recordType = fieldDecl->getType()->getAs<RecordType>();
 454     if (recordType == nullptr) {
 455         return true;
 456     }
 457     const CXXRecordDecl *recordDecl = dyn_cast<CXXRecordDecl>(recordType->getDecl());
 458     if (recordDecl == nullptr) {
 459         return true;
 460     }
 461
 462     // check if this field is derived fromVclReferenceBase
 463     if (isDerivedFromVclReferenceBase(recordDecl)) {
 464         report(
 465             DiagnosticsEngine::Warning,
 466             BASE_REF_COUNTED_CLASS " subclass allocated as a class member, should be allocated via VclPtr",
 467             fieldDecl->getLocation())
 468           << fieldDecl->getSourceRange();
 469     }
 470
 471     // If this field is a VclPtr field, then the class MUST have a dispose method
 472     if (pParentRecordDecl && isDerivedFromVclReferenceBase(pParentRecordDecl)
 473         && loplugin::DeclCheck(recordDecl).Class("VclPtr").GlobalNamespace())
 474     {
 475         bool bFoundDispose = false;
 476         for(auto methodDecl = pParentRecordDecl->method_begin();
 477             methodDecl != pParentRecordDecl->method_end(); ++methodDecl)
 478         {
 479             if (methodDecl->isInstance() && methodDecl->param_size()==0
 480                 && loplugin::DeclCheck(*methodDecl).Function("dispose"))
 481             {
 482                bFoundDispose = true;
 483                break;
 484             }
 485         }
 486         if (!bFoundDispose) {
 487             report(
 488                 DiagnosticsEngine::Warning,
 489                 BASE_REF_COUNTED_CLASS " subclass with a VclPtr field MUST override dispose() (and call its superclass dispose() as the last thing it does)",
 490                 fieldDecl->getLocation())
 491               << fieldDecl->getSourceRange();
 492         }
 493         if (!pParentRecordDecl->hasUserDeclaredDestructor()) {
 494             report(
 495                 DiagnosticsEngine::Warning,
 496                 BASE_REF_COUNTED_CLASS " subclass with a VclPtr field MUST have a user-provided destructor (that calls disposeOnce())",
 497                 fieldDecl->getLocation())
 498               << fieldDecl->getSourceRange();
 499         }
 500     }
 501
 502     return true;
 503 }
 504
 505 bool VCLWidgets::VisitParmVarDecl(ParmVarDecl const * pvDecl)
 506 {
 507     if (ignoreLocation(pvDecl)) {
 508         return true;
 509     }
 510     // ignore the stuff in the VclPtr template class
 511     const CXXMethodDecl *pMethodDecl = dyn_cast<CXXMethodDecl>(pvDecl->getDeclContext());
 512     if (loplugin::DeclCheck(pMethodDecl).MemberFunction().Class("VclPtr")
 513         .GlobalNamespace())
 514     {
 515         return true;
 516     }
 517     // we exclude this method in VclBuilder because it's so useful to have it like this
 518     auto check = loplugin::DeclCheck(pMethodDecl).Function("get");
 519     if (check.Class("VclBuilder").GlobalNamespace()
 520         || check.Class("VclBuilderContainer").GlobalNamespace())
 521     {
 522         return true;
 523     }
 524     return true;
 525 }
 526
 527
 528 static void findDisposeAndClearStatements(std::set<const FieldDecl*>& aVclPtrFields, const Stmt *pStmt)
 529 {
 530     if (!pStmt)
 531         return;
 532     if (isa<CompoundStmt>(pStmt)) {
 533         const CompoundStmt *pCompoundStatement = dyn_cast<CompoundStmt>(pStmt);
 534         for (auto i = pCompoundStatement->body_begin();
 535              i != pCompoundStatement->body_end(); ++i)
 536         {
 537             findDisposeAndClearStatements(aVclPtrFields, *i);
 538         }
 539         return;
 540     }
 541     if (isa<ForStmt>(pStmt)) {
 542         findDisposeAndClearStatements(aVclPtrFields, dyn_cast<ForStmt>(pStmt)->getBody());
 543         return;
 544     }
 545     if (isa<IfStmt>(pStmt)) {
 546         findDisposeAndClearStatements(aVclPtrFields, dyn_cast<IfStmt>(pStmt)->getThen());
 547         findDisposeAndClearStatements(aVclPtrFields, dyn_cast<IfStmt>(pStmt)->getElse());
 548         return;
 549     }
 550     if (!isa<CallExpr>(pStmt)) return;
 551     const CallExpr *pCallExpr = dyn_cast<CallExpr>(pStmt);
 552
 553     if (!pCallExpr->getDirectCallee()) return;
 554     if (!isa<CXXMethodDecl>(pCallExpr->getDirectCallee())) return;
 555     auto check = loplugin::DeclCheck(
 556         dyn_cast<CXXMethodDecl>(pCallExpr->getDirectCallee()));
 557     if (!(check.Function("disposeAndClear") || check.Function("clear")))
 558             return;
 559
 560     if (!pCallExpr->getCallee()) return;
 561
 562     if (!isa<MemberExpr>(pCallExpr->getCallee())) return;
 563     const MemberExpr *pCalleeMemberExpr = dyn_cast<MemberExpr>(pCallExpr->getCallee());
 564
 565     if (!pCalleeMemberExpr->getBase()) return;
 566     const MemberExpr *pCalleeMemberExprBase = dyn_cast<MemberExpr>(pCalleeMemberExpr->getBase()->IgnoreImpCasts());
 567     if (pCalleeMemberExprBase == nullptr) return;
 568
 569     const FieldDecl* xxx = dyn_cast_or_null<FieldDecl>(pCalleeMemberExprBase->getMemberDecl());
 570     if (xxx)
 571         aVclPtrFields.erase(xxx);
 572 }
 573
 574
 575 bool VCLWidgets::VisitFunctionDecl( const FunctionDecl* functionDecl )
 576 {
 577     if (ignoreLocation(functionDecl)) {
 578         return true;
 579     }
 580     // ignore the stuff in the VclPtr template class
 581     if (loplugin::DeclCheck(functionDecl).MemberFunction().Class("VclPtr")
 582         .GlobalNamespace())
 583     {
 584         return true;
 585     }
 586     // ignore the BASE_REF_COUNTED_CLASS::dispose() method
 587     if (loplugin::DeclCheck(functionDecl).Function("dispose")
 588         .Class(BASE_REF_COUNTED_CLASS).GlobalNamespace())
 589     {
 590         return true;
 591     }
 592     const CXXMethodDecl *pMethodDecl = dyn_cast<CXXMethodDecl>(functionDecl);
 593     if (functionDecl->hasBody() && pMethodDecl && isDerivedFromVclReferenceBase(pMethodDecl->getParent())) {
 594         // check the last thing that the dispose() method does, is to call into the superclass dispose method
 595         if (loplugin::DeclCheck(functionDecl).Function("dispose")) {
 596             if (!isDisposeCallingSuperclassDispose(pMethodDecl)) {
 597                 report(
 598                     DiagnosticsEngine::Warning,
 599                     BASE_REF_COUNTED_CLASS " subclass dispose() function MUST call dispose() of its superclass as the last thing it does",
 600                     functionDecl->getLocStart())
 601                   << functionDecl->getSourceRange();
 602            }
 603         }
 604     }
 605
 606     // check dispose method to make sure we are actually disposing all of the VclPtr fields
 607     // FIXME this is not exhaustive. We should enable shouldVisitTemplateInstantiations and look deeper inside type declarations
 608     if (pMethodDecl && pMethodDecl->isInstance() && pMethodDecl->getBody()
 609         && pMethodDecl->param_size()==0
 610         && loplugin::DeclCheck(functionDecl).Function("dispose")
 611         && isDerivedFromVclReferenceBase(pMethodDecl->getParent()) )
 612     {
 613         auto check = loplugin::DeclCheck(functionDecl).MemberFunction();
 614         if (check.Class("VirtualDevice").GlobalNamespace()
 615             || check.Class("Breadcrumb").GlobalNamespace())
 616         {
 617             return true;
 618         }
 619
 620         std::set<const FieldDecl*> aVclPtrFields;
 621         for (auto i = pMethodDecl->getParent()->field_begin();
 622              i != pMethodDecl->getParent()->field_end(); ++i)
 623         {
 624             auto const type = loplugin::TypeCheck((*i)->getType());
 625             if (type.Class("VclPtr").GlobalNamespace()) {
 626                aVclPtrFields.insert(*i);
 627             } else if (type.Class("vector").StdNamespace()
 628                        || type.Class("map").StdNamespace()
 629                        || type.Class("list").StdNamespace()
 630                        || type.Class("set").StdNamespace())
 631             {
 632                 const RecordType* recordType = dyn_cast_or_null<RecordType>((*i)->getType()->getUnqualifiedDesugaredType());
 633                 if (recordType) {
 634                     auto d = dyn_cast<ClassTemplateSpecializationDecl>(recordType->getDecl());
 635                     if (d && d->getTemplateArgs().size()>0) {
 636                         auto const type = loplugin::TypeCheck(d->getTemplateArgs()[0].getAsType());
 637                         if (type.Class("VclPtr").GlobalNamespace()) {
 638                             aVclPtrFields.insert(*i);
 639                         }
 640                     }
 641                 }
 642             }
 643         }
 644         if (!aVclPtrFields.empty()) {
 645             findDisposeAndClearStatements( aVclPtrFields, pMethodDecl->getBody() );
 646             if (!aVclPtrFields.empty()) {
 647                 //pMethodDecl->dump();
 648                 std::string aMessage = BASE_REF_COUNTED_CLASS " subclass dispose() method does not call disposeAndClear() or clear() on the following field(s): ";
 649                 for(auto s : aVclPtrFields)
 650                     aMessage += ", " + s->getNameAsString();
 651                 report(
 652                     DiagnosticsEngine::Warning,
 653                     aMessage,
 654                     functionDecl->getLocStart())
 655                   << functionDecl->getSourceRange();
 656            }
 657        }
 658     }
 659
 660     return true;
 661 }
 662
 663 bool VCLWidgets::VisitCXXDeleteExpr(const CXXDeleteExpr *pCXXDeleteExpr)
 664 {
 665     if (ignoreLocation(pCXXDeleteExpr)) {
 666         return true;
 667     }
 668     const CXXRecordDecl *pPointee = pCXXDeleteExpr->getArgument()->getType()->getPointeeCXXRecordDecl();
 669     if (pPointee && isDerivedFromVclReferenceBase(pPointee)) {
 670         SourceLocation spellingLocation = compiler.getSourceManager().getSpellingLoc(
 671                               pCXXDeleteExpr->getLocStart());
 672         StringRef filename = compiler.getSourceManager().getFilename(spellingLocation);
 673         if ( !(loplugin::isSamePathname(filename, SRCDIR "/include/vcl/vclreferencebase.hxx")))
 674         {
 675             report(
 676                 DiagnosticsEngine::Warning,
 677                 "calling delete on instance of " BASE_REF_COUNTED_CLASS " subclass, must rather call disposeAndClear()",
 678                 pCXXDeleteExpr->getLocStart())
 679               << pCXXDeleteExpr->getSourceRange();
 680         }
 681     }
 682     const ImplicitCastExpr* pImplicitCastExpr = dyn_cast<ImplicitCastExpr>(pCXXDeleteExpr->getArgument());
 683     if (!pImplicitCastExpr) {
 684         return true;
 685     }
 686     if (pImplicitCastExpr->getCastKind() != CK_UserDefinedConversion) {
 687         return true;
 688     }
 689     report(
 690         DiagnosticsEngine::Warning,
 691         "calling delete on instance of VclPtr, must rather call disposeAndClear()",
 692         pCXXDeleteExpr->getLocStart())
 693      << pCXXDeleteExpr->getSourceRange();
 694     return true;
 695 }
 696
 697
 698 /**
 699 The AST looks like:
 700 `-CXXMemberCallExpr 0xb06d8b0 'void'
 701   `-MemberExpr 0xb06d868 '<bound member function type>' ->dispose 0x9d34880
 702     `-ImplicitCastExpr 0xb06d8d8 'class SfxTabPage *' <UncheckedDerivedToBase (SfxTabPage)>
 703       `-CXXThisExpr 0xb06d850 'class SfxAcceleratorConfigPage *' this
 704
 705 */
 706 bool VCLWidgets::isDisposeCallingSuperclassDispose(const CXXMethodDecl* pMethodDecl)
 707 {
 708     const CompoundStmt *pCompoundStatement = dyn_cast<CompoundStmt>(pMethodDecl->getBody());
 709     if (!pCompoundStatement) return false;
 710     if (pCompoundStatement->size() == 0) return false;
 711     // find the last statement
 712     const CXXMemberCallExpr *pCallExpr = dyn_cast<CXXMemberCallExpr>(*pCompoundStatement->body_rbegin());
 713     if (!pCallExpr) return false;
 714     const MemberExpr *pMemberExpr = dyn_cast<MemberExpr>(pCallExpr->getCallee());
 715     if (!pMemberExpr) return false;
 716     if (!loplugin::DeclCheck(pMemberExpr->getMemberDecl()).Function("dispose")) return false;
 717     const CXXMethodDecl *pDirectCallee = dyn_cast<CXXMethodDecl>(pCallExpr->getDirectCallee());
 718     if (!pDirectCallee) return false;
 719 /* Not working yet. Partially because sometimes the superclass does not a dispose() method, so it gets passed up the chain.
 720    Need complex checking for that case.
 721     if (pDirectCallee->getParent()->getTypeForDecl() != (*pMethodDecl->getParent()->bases_begin()).getType().getTypePtr()) {
 722         report(
 723             DiagnosticsEngine::Warning,
 724             "dispose() method calling wrong baseclass, calling " + pDirectCallee->getParent()->getQualifiedNameAsString() +
 725             " should be calling " + (*pMethodDecl->getParent()->bases_begin()).getType().getAsString(),
 726             pCallExpr->getLocStart())
 727           << pCallExpr->getSourceRange();
 728         return false;
 729     }*/
 730     return true;
 731 }
 732
 733 bool containsVclPtr(const clang::Type* pType0);
 734
 735 bool containsVclPtr(const QualType& qType) {
 736     auto check = loplugin::TypeCheck(qType);
 737     if (check.Class("ScopedVclPtr").GlobalNamespace()
 738         || check.Class("ScopedVclPtrInstance").GlobalNamespace()
 739         || check.Class("VclPtr").GlobalNamespace()
 740         || check.Class("VclPtrInstance").GlobalNamespace())
 741     {
 742         return true;
 743     }
 744     return containsVclPtr(qType.getTypePtr());
 745 }
 746
 747 bool containsVclPtr(const clang::Type* pType0) {
 748     if (!pType0)
 749         return false;
 750     const clang::Type* pType = pType0->getUnqualifiedDesugaredType();
 751     if (!pType)
 752         return false;
 753     if (pType->isPointerType()) {
 754         return false;
 755     } else if (pType->isArrayType()) {
 756         const clang::ArrayType* pArrayType = dyn_cast<clang::ArrayType>(pType);
 757         QualType elementType = pArrayType->getElementType();
 758         return containsVclPtr(elementType);
 759     } else {
 760         const CXXRecordDecl* pRecordDecl = pType->getAsCXXRecordDecl();
 761         if (pRecordDecl)
 762         {
 763             auto check = loplugin::DeclCheck(pRecordDecl);
 764             if (check.Class("ScopedVclPtr").GlobalNamespace()
 765                 || check.Class("ScopedVclPtrInstance").GlobalNamespace()
 766                 || check.Class("VclPtr").GlobalNamespace()
 767                 || check.Class("VclPtrInstance").GlobalNamespace())
 768             {
 769                 return true;
 770             }
 771             for(auto fieldDecl = pRecordDecl->field_begin();
 772                 fieldDecl != pRecordDecl->field_end(); ++fieldDecl)
 773             {
 774                 const RecordType *pFieldRecordType = fieldDecl->getType()->getAs<RecordType>();
 775                 if (pFieldRecordType && containsVclPtr(pFieldRecordType)) {
 776                     return true;
 777                 }
 778             }
 779             for(auto baseSpecifier = pRecordDecl->bases_begin();
 780                 baseSpecifier != pRecordDecl->bases_end(); ++baseSpecifier)
 781             {
 782                 const RecordType *pFieldRecordType = baseSpecifier->getType()->getAs<RecordType>();
 783                 if (pFieldRecordType && containsVclPtr(pFieldRecordType)) {
 784                     return true;
 785                 }
 786             }
 787         }
 788     }
 789     return false;
 790 }
 791
 792 bool VCLWidgets::VisitCallExpr(const CallExpr* pCallExpr)
 793 {
 794     if (ignoreLocation(pCallExpr)) {
 795         return true;
 796     }
 797     FunctionDecl const * fdecl = pCallExpr->getDirectCallee();
 798     if (fdecl == nullptr) {
 799         return true;
 800     }
 801     std::string qname { fdecl->getQualifiedNameAsString() };
 802     if (qname.find("memcpy") == std::string::npos
 803          && qname.find("bcopy") == std::string::npos
 804          && qname.find("memmove") == std::string::npos
 805          && qname.find("rtl_copy") == std::string::npos) {
 806         return true;
 807     }
 808     mbCheckingMemcpy = true;
 809     Stmt * pStmt = const_cast<Stmt*>(static_cast<const Stmt*>(pCallExpr->getArg(0)));
 810     TraverseStmt(pStmt);
 811     mbCheckingMemcpy = false;
 812     return true;
 813 }
 814
 815 bool VCLWidgets::VisitDeclRefExpr(const DeclRefExpr* pDeclRefExpr)
 816 {
 817     if (!mbCheckingMemcpy) {
 818         return true;
 819     }
 820     if (ignoreLocation(pDeclRefExpr)) {
 821         return true;
 822     }
 823     QualType pType = pDeclRefExpr->getDecl()->getType();
 824     if (pType->isPointerType()) {
 825         pType = pType->getPointeeType();
 826     }
 827     if (!containsVclPtr(pType)) {
 828         return true;
 829     }
 830     report(
 831         DiagnosticsEngine::Warning,
 832         "Calling memcpy on a type which contains a VclPtr",
 833         pDeclRefExpr->getExprLoc());
 834     return true;
 835 }
 836
 837 bool VCLWidgets::VisitCXXConstructExpr( const CXXConstructExpr* constructExpr )
 838 {
 839     if (ignoreLocation(constructExpr)) {
 840         return true;
 841     }
 842     if (constructExpr->getConstructionKind() != CXXConstructExpr::CK_Complete) {
 843         return true;
 844     }
 845     const CXXConstructorDecl* pConstructorDecl = constructExpr->getConstructor();
 846     const CXXRecordDecl* recordDecl = pConstructorDecl->getParent();
 847     if (isDerivedFromVclReferenceBase(recordDecl)) {
 848         StringRef aFileName = compiler.getSourceManager().getFilename(compiler.getSourceManager().getSpellingLoc(constructExpr->getLocStart()));
 849         if (!loplugin::isSamePathname(aFileName, SRCDIR "/include/vcl/vclptr.hxx")) {
 850             report(
 851                 DiagnosticsEngine::Warning,
 852                 "Calling constructor of a VclReferenceBase-derived type directly; all such creation should go via VclPtr<>::Create",
 853                 constructExpr->getExprLoc());
 854         }
 855     }
 856     return true;
 857 }
 858
 859 loplugin::Plugin::Registration< VCLWidgets > X("vclwidgets");
 860
 861 }
 862
 863 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */