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 "compat.hxx"
  17 #include "config_clang.h"
  18 #include "clang/AST/CXXInheritance.h"
  19
  20 // Final goal: Checker for VCL widget references. Makes sure that VCL Window subclasses are properly referenced counted and dispose()'ed.
  21 //
  22 // But at the moment it just finds subclasses of Window which are not heap-allocated
  23 //
  24 // TODO do I need to check for local and static variables, too ?
  25 // TODO when we have a dispose() method, verify that the dispose() methods releases all of the Window references
  26 // TODO when we have a dispose() method, verify that it calls the super-class dispose() method at some point.
  27
  28 namespace {
  29
  30 class VCLWidgets:
  31     public loplugin::FilteringPlugin<VCLWidgets>
  32 {
  33 public:
  34     explicit VCLWidgets(loplugin::InstantiationData const & data): FilteringPlugin(data)
  35     {}
  36
  37     virtual void run() override { TraverseDecl(compiler.getASTContext().getTranslationUnitDecl()); }
  38
  39     bool shouldVisitTemplateInstantiations () const { return true; }
  40
  41     bool VisitVarDecl(const VarDecl *);
  42     bool VisitFieldDecl(const FieldDecl *);
  43     bool VisitParmVarDecl(const ParmVarDecl *);
  44     bool VisitFunctionDecl(const FunctionDecl *);
  45     bool VisitCXXDestructorDecl(const CXXDestructorDecl *);
  46     bool VisitCXXDeleteExpr(const CXXDeleteExpr *);
  47     bool VisitCallExpr(const CallExpr *);
  48     bool VisitDeclRefExpr(const DeclRefExpr *);
  49     bool VisitCXXConstructExpr(const CXXConstructExpr *);
  50     bool VisitBinaryOperator(const BinaryOperator *);
  51 private:
  52     void checkAssignmentForVclPtrToRawConversion(const SourceLocation& sourceLoc, const clang::Type* lhsType, const Expr* rhs);
  53     bool isDisposeCallingSuperclassDispose(const CXXMethodDecl* pMethodDecl);
  54     bool mbCheckingMemcpy = false;
  55 };
  56
  57 #define BASE_REF_COUNTED_CLASS "VclReferenceBase"
  58
  59 bool BaseCheckNotWindowSubclass(const CXXRecordDecl *BaseDefinition) {
  60     return !loplugin::DeclCheck(BaseDefinition).Class(BASE_REF_COUNTED_CLASS)
  61         .GlobalNamespace();
  62 }
  63
  64 bool isDerivedFromVclReferenceBase(const CXXRecordDecl *decl) {
  65     if (!decl)
  66         return false;
  67     if (loplugin::DeclCheck(decl).Class(BASE_REF_COUNTED_CLASS)
  68         .GlobalNamespace())
  69     {
  70         return true;
  71     }
  72     if (!decl->hasDefinition()) {
  73         return false;
  74     }
  75     if (// not sure what hasAnyDependentBases() does,
  76         // but it avoids classes we don't want, e.g. WeakAggComponentImplHelper1
  77         !decl->hasAnyDependentBases() &&
  78         !decl->forallBases(BaseCheckNotWindowSubclass)) {
  79         return true;
  80     }
  81     return false;
  82 }
  83
  84 bool containsVclReferenceBaseSubclass(const clang::Type* pType0);
  85
  86 bool containsVclReferenceBaseSubclass(const QualType& qType) {
  87     auto check = loplugin::TypeCheck(qType);
  88     if (check.Class("ScopedVclPtr").GlobalNamespace()
  89         || check.Class("ScopedVclPtrInstance").GlobalNamespace()
  90         || check.Class("VclPtr").GlobalNamespace()
  91         || check.Class("VclPtrInstance").GlobalNamespace())
  92     {
  93         return false;
  94     }
  95     return containsVclReferenceBaseSubclass(qType.getTypePtr());
  96 }
  97
  98 bool containsVclReferenceBaseSubclass(const clang::Type* pType0) {
  99     if (!pType0)
 100         return false;
 101     const clang::Type* pType = pType0->getUnqualifiedDesugaredType();
 102     if (!pType)
 103         return false;
 104     const CXXRecordDecl* pRecordDecl = pType->getAsCXXRecordDecl();
 105     if (pRecordDecl) {
 106         const ClassTemplateSpecializationDecl* pTemplate = dyn_cast<ClassTemplateSpecializationDecl>(pRecordDecl);
 107         if (pTemplate) {
 108             auto check = loplugin::DeclCheck(pTemplate);
 109             if (check.Class("VclStatusListener").GlobalNamespace()) {
 110                 return false;
 111             }
 112             bool link = bool(check.Class("Link").GlobalNamespace());
 113             for(unsigned i=0; i<pTemplate->getTemplateArgs().size(); ++i) {
 114                 const TemplateArgument& rArg = pTemplate->getTemplateArgs()[i];
 115                 if (rArg.getKind() == TemplateArgument::ArgKind::Type &&
 116                     containsVclReferenceBaseSubclass(rArg.getAsType()))
 117                 {
 118                     // OK for first template argument of tools/link.hxx Link
 119                     // to be a Window-derived pointer:
 120                     if (!link || i != 0) {
 121                         return true;
 122                     }
 123                 }
 124             }
 125         }
 126     }
 127     if (pType->isPointerType()) {
 128         QualType pointeeType = pType->getPointeeType();
 129         return containsVclReferenceBaseSubclass(pointeeType);
 130     } else if (pType->isArrayType()) {
 131         const clang::ArrayType* pArrayType = dyn_cast<clang::ArrayType>(pType);
 132         QualType elementType = pArrayType->getElementType();
 133         return containsVclReferenceBaseSubclass(elementType);
 134     } else {
 135         return isDerivedFromVclReferenceBase(pRecordDecl);
 136     }
 137 }
 138
 139 bool VCLWidgets::VisitCXXDestructorDecl(const CXXDestructorDecl* pCXXDestructorDecl)
 140 {
 141     if (ignoreLocation(pCXXDestructorDecl)) {
 142         return true;
 143     }
 144     if (!pCXXDestructorDecl->isThisDeclarationADefinition()) {
 145         return true;
 146     }
 147     const CXXRecordDecl * pRecordDecl = pCXXDestructorDecl->getParent();
 148     // ignore
 149     if (loplugin::DeclCheck(pRecordDecl).Class(BASE_REF_COUNTED_CLASS)
 150         .GlobalNamespace())
 151     {
 152         return true;
 153     }
 154     // check if this class is derived from VclReferenceBase
 155     if (!isDerivedFromVclReferenceBase(pRecordDecl)) {
 156         return true;
 157     }
 158     // check if we have any VclPtr<> fields
 159     bool bFoundVclPtrField = false;
 160     for(auto fieldDecl = pRecordDecl->field_begin();
 161         fieldDecl != pRecordDecl->field_end(); ++fieldDecl)
 162     {
 163         const RecordType *pFieldRecordType = fieldDecl->getType()->getAs<RecordType>();
 164         if (pFieldRecordType) {
 165             if (loplugin::DeclCheck(pFieldRecordType->getDecl())
 166                 .Class("VclPtr").GlobalNamespace())
 167             {
 168                bFoundVclPtrField = true;
 169                break;
 170             }
 171        }
 172     }
 173     // check if there is a dispose() method
 174     bool bFoundDispose = false;
 175     for(auto methodDecl = pRecordDecl->method_begin();
 176         methodDecl != pRecordDecl->method_end(); ++methodDecl)
 177     {
 178         if (methodDecl->isInstance() && methodDecl->param_size()==0
 179             && loplugin::DeclCheck(*methodDecl).Function("dispose"))
 180         {
 181            bFoundDispose = true;
 182            break;
 183         }
 184     }
 185     const CompoundStmt *pCompoundStatement = dyn_cast_or_null<CompoundStmt>(pCXXDestructorDecl->getBody());
 186     // having an empty body and no dispose() method is fine
 187     if (!bFoundVclPtrField && !bFoundDispose && (!pCompoundStatement || pCompoundStatement->size() == 0)) {
 188         return true;
 189     }
 190     if (bFoundVclPtrField && (!pCompoundStatement || pCompoundStatement->size() == 0)) {
 191         report(
 192             DiagnosticsEngine::Warning,
 193             BASE_REF_COUNTED_CLASS " subclass with VclPtr field must call disposeOnce() from its destructor",
 194             pCXXDestructorDecl->getBeginLoc())
 195           << pCXXDestructorDecl->getSourceRange();
 196         return true;
 197     }
 198     // Check that the destructor for a BASE_REF_COUNTED_CLASS subclass either
 199     // only calls disposeOnce() or, if !bFoundVclPtrField, does nothing at all:
 200     bool bOk = false;
 201     if (pCompoundStatement) {
 202         bool bFoundDisposeOnce = false;
 203         int nNumExtraStatements = 0;
 204         for (auto i = pCompoundStatement->body_begin();
 205              i != pCompoundStatement->body_end(); ++i)
 206         {
 207             //TODO: The below erroneously also skips past entire statements like
 208             //
 209             //  assert(true), ...;
 210             //
 211             auto skip = false;
 212             for (auto loc = (*i)->getBeginLoc();
 213                  compiler.getSourceManager().isMacroBodyExpansion(loc);
 214                  loc = compiler.getSourceManager().getImmediateMacroCallerLoc(
 215                      loc))
 216             {
 217                 auto const name = Lexer::getImmediateMacroName(
 218                     loc, compiler.getSourceManager(), compiler.getLangOpts());
 219                 if (name == "SAL_DEBUG" || name == "assert") {
 220                     skip = true;
 221                     break;
 222                 }
 223             }
 224             if (skip) {
 225                 continue;
 226             }
 227             if (auto const pCallExpr = dyn_cast<CXXMemberCallExpr>(*i)) {
 228                 if( const FunctionDecl* func = pCallExpr->getDirectCallee()) {
 229                     if( func->getNumParams() == 0 && func->getIdentifier() != NULL
 230                         && ( func->getName() == "disposeOnce" )) {
 231                         bFoundDisposeOnce = true;
 232                         continue;
 233                     }
 234                 }
 235             }
 236             nNumExtraStatements++;
 237         }
 238         bOk = (bFoundDisposeOnce || !bFoundVclPtrField)
 239             && nNumExtraStatements == 0;
 240     }
 241     if (!bOk) {
 242         SourceLocation spellingLocation = compiler.getSourceManager().getSpellingLoc(
 243                               pCXXDestructorDecl->getBeginLoc());
 244         StringRef filename = getFilenameOfLocation(spellingLocation);
 245         if (   !(loplugin::isSamePathname(filename, SRCDIR "/vcl/source/window/window.cxx"))
 246             && !(loplugin::isSamePathname(filename, SRCDIR "/vcl/source/gdi/virdev.cxx"))
 247             && !(loplugin::isSamePathname(filename, SRCDIR "/vcl/qa/cppunit/lifecycle.cxx"))
 248             && !(loplugin::isSamePathname(filename, SRCDIR "/sfx2/source/dialog/tabdlg.cxx")) )
 249         {
 250             report(
 251                 DiagnosticsEngine::Warning,
 252                 BASE_REF_COUNTED_CLASS " subclass should have nothing in its destructor but a call to disposeOnce()",
 253                 pCXXDestructorDecl->getBeginLoc())
 254               << pCXXDestructorDecl->getSourceRange();
 255         }
 256     }
 257     return true;
 258 }
 259
 260 bool VCLWidgets::VisitBinaryOperator(const BinaryOperator * binaryOperator)
 261 {
 262     if (ignoreLocation(binaryOperator)) {
 263         return true;
 264     }
 265     if ( !binaryOperator->isAssignmentOp() ) {
 266         return true;
 267     }
 268     SourceLocation spellingLocation = compiler.getSourceManager().getSpellingLoc(
 269                           binaryOperator->getBeginLoc());
 270     checkAssignmentForVclPtrToRawConversion(spellingLocation, binaryOperator->getLHS()->getType().getTypePtr(), binaryOperator->getRHS());
 271     return true;
 272 }
 273
 274 // Look for places where we are accidentally assigning a returned-by-value VclPtr<T> to a T*, which generally
 275 // ends up in a use-after-free.
 276 void VCLWidgets::checkAssignmentForVclPtrToRawConversion(const SourceLocation& spellingLocation, const clang::Type* lhsType, const Expr* rhs)
 277 {
 278     if (!lhsType || !isa<clang::PointerType>(lhsType)) {
 279         return;
 280     }
 281     if (!rhs) {
 282         return;
 283     }
 284     StringRef filename = getFilenameOfLocation(spellingLocation);
 285     if (loplugin::isSamePathname(filename, SRCDIR "/include/rtl/ref.hxx")) {
 286         return;
 287     }
 288     const CXXRecordDecl* pointeeClass = lhsType->getPointeeType()->getAsCXXRecordDecl();
 289     if (!isDerivedFromVclReferenceBase(pointeeClass)) {
 290         return;
 291     }
 292
 293     // if we have T* on the LHS and VclPtr<T> on the RHS, we expect to see either
 294     // an ImplicitCastExpr
 295     // or an ExprWithCleanups and then an ImplicitCastExpr
 296     if (auto implicitCastExpr = dyn_cast<ImplicitCastExpr>(rhs)) {
 297         if (implicitCastExpr->getCastKind() != CK_UserDefinedConversion) {
 298             return;
 299         }
 300         rhs = rhs->IgnoreCasts();
 301     } else if (auto exprWithCleanups = dyn_cast<ExprWithCleanups>(rhs)) {
 302         if (auto implicitCastExpr = dyn_cast<ImplicitCastExpr>(exprWithCleanups->getSubExpr())) {
 303             if (implicitCastExpr->getCastKind() != CK_UserDefinedConversion) {
 304                 return;
 305             }
 306             rhs = exprWithCleanups->IgnoreCasts();
 307         } else {
 308             return;
 309         }
 310     } else {
 311         return;
 312     }
 313     if (isa<CXXNullPtrLiteralExpr>(rhs)) {
 314         return;
 315     }
 316     if (isa<CXXThisExpr>(rhs)) {
 317         return;
 318     }
 319
 320     // ignore assignments from a member field to a local variable, to avoid unnecessary refcounting traffic
 321     if (auto callExpr = dyn_cast<CXXMemberCallExpr>(rhs)) {
 322         if (auto calleeMemberExpr = dyn_cast<MemberExpr>(callExpr->getCallee())) {
 323             if ((calleeMemberExpr = dyn_cast<MemberExpr>(calleeMemberExpr->getBase()->IgnoreImpCasts()))) {
 324                 if (isa<FieldDecl>(calleeMemberExpr->getMemberDecl())) {
 325                     return;
 326                 }
 327             }
 328         }
 329     }
 330
 331     // ignore assignments from a local variable to a local variable, to avoid unnecessary refcounting traffic
 332     if (auto callExpr = dyn_cast<CXXMemberCallExpr>(rhs)) {
 333         if (auto calleeMemberExpr = dyn_cast<MemberExpr>(callExpr->getCallee())) {
 334             if (auto declRefExpr = dyn_cast<DeclRefExpr>(calleeMemberExpr->getBase()->IgnoreImpCasts())) {
 335                 if (isa<VarDecl>(declRefExpr->getDecl())) {
 336                     return;
 337                 }
 338             }
 339         }
 340     }
 341     if (auto declRefExpr = dyn_cast<DeclRefExpr>(rhs->IgnoreImpCasts())) {
 342         if (isa<VarDecl>(declRefExpr->getDecl())) {
 343              return;
 344         }
 345     }
 346
 347     report(
 348         DiagnosticsEngine::Warning,
 349         "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",
 350          rhs->getSourceRange().getBegin())
 351         << rhs->getSourceRange();
 352 }
 353
 354 bool VCLWidgets::VisitVarDecl(const VarDecl * pVarDecl) {
 355     if (ignoreLocation(pVarDecl)) {
 356         return true;
 357     }
 358     if (isa<ParmVarDecl>(pVarDecl)) {
 359         return true;
 360     }
 361     SourceLocation spellingLocation = compiler.getSourceManager().getSpellingLoc(
 362                           pVarDecl->getBeginLoc());
 363     if (pVarDecl->getInit()) {
 364         checkAssignmentForVclPtrToRawConversion(spellingLocation, pVarDecl->getType().getTypePtr(), pVarDecl->getInit());
 365     }
 366     StringRef aFileName = getFilenameOfLocation(spellingLocation);
 367     if (loplugin::isSamePathname(aFileName, SRCDIR "/include/vcl/vclptr.hxx"))
 368         return true;
 369     if (loplugin::isSamePathname(aFileName, SRCDIR "/vcl/source/window/layout.cxx"))
 370         return true;
 371     // allowlist the valid things that can contain pointers.
 372     // It is containing stuff like std::unique_ptr we get worried
 373     if (pVarDecl->getType()->isArrayType()) {
 374         return true;
 375     }
 376     auto tc = loplugin::TypeCheck(pVarDecl->getType());
 377     if (tc.Pointer()
 378         || tc.Class("map").StdNamespace()
 379         || tc.Class("multimap").StdNamespace()
 380         || tc.Class("vector").StdNamespace()
 381         || tc.Class("list").StdNamespace()
 382         || tc.Class("mem_fun1_t").StdNamespace()
 383           // registration template thing, doesn't actually allocate anything we need to care about
 384         || tc.Class("OMultiInstanceAutoRegistration").Namespace("compmodule").GlobalNamespace())
 385     {
 386         return true;
 387     }
 388     // Apparently I should be doing some kind of lookup for a partial specialisations of std::iterator_traits<T> to see if an
 389     // object is an iterator, but that sounds like too much work
 390     auto t = pVarDecl->getType().getDesugaredType(compiler.getASTContext());
 391     std::string s = t.getAsString();
 392     if (s.find("iterator") != std::string::npos
 393         || loplugin::TypeCheck(t).Class("__wrap_iter").StdNamespace())
 394     {
 395         return true;
 396     }
 397     // 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
 398     // it's an ElaboratedType (whatever that is)
 399     if (s.find("pair") != std::string::npos) {
 400         return true;
 401     }
 402
 403     if (containsVclReferenceBaseSubclass(pVarDecl->getType())) {
 404         report(
 405             DiagnosticsEngine::Warning,
 406             BASE_REF_COUNTED_CLASS " subclass %0 should be wrapped in VclPtr",
 407             pVarDecl->getLocation())
 408             << pVarDecl->getType() << pVarDecl->getSourceRange();
 409         return true;
 410     }
 411     return true;
 412 }
 413
 414 bool VCLWidgets::VisitFieldDecl(const FieldDecl * fieldDecl) {
 415     if (ignoreLocation(fieldDecl)) {
 416         return true;
 417     }
 418     StringRef aFileName = getFilenameOfLocation(
 419         compiler.getSourceManager().getSpellingLoc(fieldDecl->getBeginLoc()));
 420     if (loplugin::isSamePathname(aFileName, SRCDIR "/include/vcl/vclptr.hxx"))
 421         return true;
 422     if (loplugin::isSamePathname(aFileName, SRCDIR "/include/rtl/ref.hxx"))
 423         return true;
 424     if (loplugin::isSamePathname(aFileName, SRCDIR "/include/o3tl/enumarray.hxx"))
 425         return true;
 426     if (loplugin::isSamePathname(aFileName, SRCDIR "/vcl/source/window/layout.cxx"))
 427         return true;
 428     if (fieldDecl->isBitField()) {
 429         return true;
 430     }
 431     const CXXRecordDecl *pParentRecordDecl = isa<RecordDecl>(fieldDecl->getDeclContext()) ? dyn_cast<CXXRecordDecl>(fieldDecl->getParent()) : nullptr;
 432     if (loplugin::DeclCheck(pParentRecordDecl).Class("VclPtr")
 433         .GlobalNamespace())
 434     {
 435         return true;
 436     }
 437     if (containsVclReferenceBaseSubclass(fieldDecl->getType())) {
 438         // have to ignore this for now, nasty reverse dependency from tools->vcl
 439         auto check = loplugin::DeclCheck(pParentRecordDecl);
 440         if (!(check.Struct("ImplErrorContext").GlobalNamespace()
 441               || check.Class("ScHFEditPage").GlobalNamespace()))
 442         {
 443             report(
 444                 DiagnosticsEngine::Warning,
 445                 BASE_REF_COUNTED_CLASS " subclass %0 declared as a pointer member, should be wrapped in VclPtr",
 446                 fieldDecl->getLocation())
 447                 << fieldDecl->getType() << fieldDecl->getSourceRange();
 448             if (auto parent = dyn_cast<ClassTemplateSpecializationDecl>(fieldDecl->getParent())) {
 449                 report(
 450                     DiagnosticsEngine::Note,
 451                     "template field here",
 452                     parent->getPointOfInstantiation());
 453             }
 454             return true;
 455         }
 456     }
 457     const RecordType *recordType = fieldDecl->getType()->getAs<RecordType>();
 458     if (recordType == nullptr) {
 459         return true;
 460     }
 461     const CXXRecordDecl *recordDecl = dyn_cast<CXXRecordDecl>(recordType->getDecl());
 462     if (recordDecl == nullptr) {
 463         return true;
 464     }
 465
 466     // check if this field is derived fromVclReferenceBase
 467     if (isDerivedFromVclReferenceBase(recordDecl)) {
 468         report(
 469             DiagnosticsEngine::Warning,
 470             BASE_REF_COUNTED_CLASS " subclass allocated as a class member, should be allocated via VclPtr",
 471             fieldDecl->getLocation())
 472           << fieldDecl->getSourceRange();
 473     }
 474
 475     // If this field is a VclPtr field, then the class MUST have a dispose method
 476     if (pParentRecordDecl && isDerivedFromVclReferenceBase(pParentRecordDecl)
 477         && loplugin::DeclCheck(recordDecl).Class("VclPtr").GlobalNamespace())
 478     {
 479         bool bFoundDispose = false;
 480         for(auto methodDecl = pParentRecordDecl->method_begin();
 481             methodDecl != pParentRecordDecl->method_end(); ++methodDecl)
 482         {
 483             if (methodDecl->isInstance() && methodDecl->param_size()==0
 484                 && loplugin::DeclCheck(*methodDecl).Function("dispose"))
 485             {
 486                bFoundDispose = true;
 487                break;
 488             }
 489         }
 490         if (!bFoundDispose) {
 491             report(
 492                 DiagnosticsEngine::Warning,
 493                 BASE_REF_COUNTED_CLASS " subclass with a VclPtr field MUST override dispose() (and call its superclass dispose() as the last thing it does)",
 494                 fieldDecl->getLocation())
 495               << fieldDecl->getSourceRange();
 496         }
 497         if (!pParentRecordDecl->hasUserDeclaredDestructor()) {
 498             report(
 499                 DiagnosticsEngine::Warning,
 500                 BASE_REF_COUNTED_CLASS " subclass with a VclPtr field MUST have a user-provided destructor (that calls disposeOnce())",
 501                 fieldDecl->getLocation())
 502               << fieldDecl->getSourceRange();
 503         }
 504     }
 505
 506     return true;
 507 }
 508
 509 bool VCLWidgets::VisitParmVarDecl(ParmVarDecl const * pvDecl)
 510 {
 511     if (ignoreLocation(pvDecl)) {
 512         return true;
 513     }
 514     // ignore the stuff in the VclPtr template class
 515     const CXXMethodDecl *pMethodDecl = dyn_cast<CXXMethodDecl>(pvDecl->getDeclContext());
 516     if (loplugin::DeclCheck(pMethodDecl).MemberFunction().Class("VclPtr")
 517         .GlobalNamespace())
 518     {
 519         return true;
 520     }
 521     // we exclude this method in VclBuilder because it's so useful to have it like this
 522     auto check = loplugin::DeclCheck(pMethodDecl).Function("get");
 523     if (check.Class("VclBuilder").GlobalNamespace()
 524         || check.Class("VclBuilderContainer").GlobalNamespace())
 525     {
 526         return true;
 527     }
 528     return true;
 529 }
 530
 531
 532 static void findDisposeAndClearStatements(std::set<const FieldDecl*>& aVclPtrFields, const Stmt *pStmt)
 533 {
 534     if (!pStmt)
 535         return;
 536     if (isa<CompoundStmt>(pStmt)) {
 537         const CompoundStmt *pCompoundStatement = dyn_cast<CompoundStmt>(pStmt);
 538         for (auto i = pCompoundStatement->body_begin();
 539              i != pCompoundStatement->body_end(); ++i)
 540         {
 541             findDisposeAndClearStatements(aVclPtrFields, *i);
 542         }
 543         return;
 544     }
 545     if (isa<ForStmt>(pStmt)) {
 546         findDisposeAndClearStatements(aVclPtrFields, dyn_cast<ForStmt>(pStmt)->getBody());
 547         return;
 548     }
 549     if (isa<IfStmt>(pStmt)) {
 550         findDisposeAndClearStatements(aVclPtrFields, dyn_cast<IfStmt>(pStmt)->getThen());
 551         findDisposeAndClearStatements(aVclPtrFields, dyn_cast<IfStmt>(pStmt)->getElse());
 552         return;
 553     }
 554     if (!isa<CallExpr>(pStmt)) return;
 555     const CallExpr *pCallExpr = dyn_cast<CallExpr>(pStmt);
 556
 557     if (!pCallExpr->getDirectCallee()) return;
 558     if (!isa<CXXMethodDecl>(pCallExpr->getDirectCallee())) return;
 559     auto check = loplugin::DeclCheck(
 560         dyn_cast<CXXMethodDecl>(pCallExpr->getDirectCallee()));
 561     if (!(check.Function("disposeAndClear") || check.Function("clear")))
 562             return;
 563
 564     if (!pCallExpr->getCallee()) return;
 565
 566     if (!isa<MemberExpr>(pCallExpr->getCallee())) return;
 567     const MemberExpr *pCalleeMemberExpr = dyn_cast<MemberExpr>(pCallExpr->getCallee());
 568
 569     if (!pCalleeMemberExpr->getBase()) return;
 570     const MemberExpr *pCalleeMemberExprBase = dyn_cast<MemberExpr>(pCalleeMemberExpr->getBase()->IgnoreImpCasts());
 571     if (pCalleeMemberExprBase == nullptr) return;
 572
 573     const FieldDecl* xxx = dyn_cast_or_null<FieldDecl>(pCalleeMemberExprBase->getMemberDecl());
 574     if (xxx)
 575         aVclPtrFields.erase(xxx);
 576 }
 577
 578
 579 bool VCLWidgets::VisitFunctionDecl( const FunctionDecl* functionDecl )
 580 {
 581     if (ignoreLocation(functionDecl)) {
 582         return true;
 583     }
 584     // ignore the stuff in the VclPtr template class
 585     if (loplugin::DeclCheck(functionDecl).MemberFunction().Class("VclPtr")
 586         .GlobalNamespace())
 587     {
 588         return true;
 589     }
 590     // ignore the BASE_REF_COUNTED_CLASS::dispose() method
 591     if (loplugin::DeclCheck(functionDecl).Function("dispose")
 592         .Class(BASE_REF_COUNTED_CLASS).GlobalNamespace())
 593     {
 594         return true;
 595     }
 596     const CXXMethodDecl *pMethodDecl = dyn_cast<CXXMethodDecl>(functionDecl);
 597     if (functionDecl->hasBody() && pMethodDecl && isDerivedFromVclReferenceBase(pMethodDecl->getParent())) {
 598         // check the last thing that the dispose() method does, is to call into the superclass dispose method
 599         if (loplugin::DeclCheck(functionDecl).Function("dispose")) {
 600             if (!isDisposeCallingSuperclassDispose(pMethodDecl)) {
 601                 // We specifically have to clear a member variable AFTER calling super::dispose() here, unfortunately
 602                 if (!loplugin::DeclCheck(pMethodDecl->getParent()).Class("WindowOutputDevice"))
 603                     report(
 604                         DiagnosticsEngine::Warning,
 605                         BASE_REF_COUNTED_CLASS " subclass dispose() function MUST call dispose() of its superclass as the last thing it does",
 606                         functionDecl->getBeginLoc())
 607                       << functionDecl->getSourceRange();
 608            }
 609         }
 610     }
 611
 612     // check dispose method to make sure we are actually disposing all of the VclPtr fields
 613     // FIXME this is not exhaustive. We should enable shouldVisitTemplateInstantiations and look deeper inside type declarations
 614     if (pMethodDecl && pMethodDecl->isInstance() && pMethodDecl->getBody()
 615         && pMethodDecl->param_size()==0
 616         && loplugin::DeclCheck(functionDecl).Function("dispose")
 617         && isDerivedFromVclReferenceBase(pMethodDecl->getParent()) )
 618     {
 619         auto check = loplugin::DeclCheck(functionDecl).MemberFunction();
 620         if (check.Class("VirtualDevice").GlobalNamespace()
 621             || check.Class("Breadcrumb").GlobalNamespace())
 622         {
 623             return true;
 624         }
 625
 626         std::set<const FieldDecl*> aVclPtrFields;
 627         for (auto i = pMethodDecl->getParent()->field_begin();
 628              i != pMethodDecl->getParent()->field_end(); ++i)
 629         {
 630             auto const type = loplugin::TypeCheck((*i)->getType());
 631             if (type.Class("VclPtr").GlobalNamespace()) {
 632                aVclPtrFields.insert(*i);
 633             } else if (type.Class("vector").StdNamespace()
 634                        || type.Class("map").StdNamespace()
 635                        || type.Class("list").StdNamespace()
 636                        || type.Class("set").StdNamespace())
 637             {
 638                 const RecordType* recordType = dyn_cast_or_null<RecordType>((*i)->getType()->getUnqualifiedDesugaredType());
 639                 if (recordType) {
 640                     auto d = dyn_cast<ClassTemplateSpecializationDecl>(recordType->getDecl());
 641                     if (d && d->getTemplateArgs().size()>0) {
 642                         auto const type = loplugin::TypeCheck(d->getTemplateArgs()[0].getAsType());
 643                         if (type.Class("VclPtr").GlobalNamespace()) {
 644                             aVclPtrFields.insert(*i);
 645                         }
 646                     }
 647                 }
 648             }
 649         }
 650         if (!aVclPtrFields.empty()) {
 651             findDisposeAndClearStatements( aVclPtrFields, pMethodDecl->getBody() );
 652             if (!aVclPtrFields.empty()) {
 653                 //pMethodDecl->dump();
 654                 std::string aMessage = BASE_REF_COUNTED_CLASS " subclass dispose() method does not call disposeAndClear() or clear() on the following field(s): ";
 655                 for(auto s : aVclPtrFields)
 656                     aMessage += ", " + s->getNameAsString();
 657                 report(
 658                     DiagnosticsEngine::Warning,
 659                     aMessage,
 660                     functionDecl->getBeginLoc())
 661                   << functionDecl->getSourceRange();
 662            }
 663        }
 664     }
 665
 666     return true;
 667 }
 668
 669 bool VCLWidgets::VisitCXXDeleteExpr(const CXXDeleteExpr *pCXXDeleteExpr)
 670 {
 671     if (ignoreLocation(pCXXDeleteExpr)) {
 672         return true;
 673     }
 674     const CXXRecordDecl *pPointee = pCXXDeleteExpr->getArgument()->getType()->getPointeeCXXRecordDecl();
 675     if (pPointee && isDerivedFromVclReferenceBase(pPointee)) {
 676         SourceLocation spellingLocation = compiler.getSourceManager().getSpellingLoc(
 677                               pCXXDeleteExpr->getBeginLoc());
 678         StringRef filename = getFilenameOfLocation(spellingLocation);
 679         if ( !(loplugin::isSamePathname(filename, SRCDIR "/include/vcl/vclreferencebase.hxx")))
 680         {
 681             report(
 682                 DiagnosticsEngine::Warning,
 683                 "calling delete on instance of " BASE_REF_COUNTED_CLASS " subclass, must rather call disposeAndClear()",
 684                 pCXXDeleteExpr->getBeginLoc())
 685               << pCXXDeleteExpr->getSourceRange();
 686         }
 687     }
 688     const ImplicitCastExpr* pImplicitCastExpr = dyn_cast<ImplicitCastExpr>(pCXXDeleteExpr->getArgument());
 689     if (!pImplicitCastExpr) {
 690         return true;
 691     }
 692     if (pImplicitCastExpr->getCastKind() != CK_UserDefinedConversion) {
 693         return true;
 694     }
 695     if (!loplugin::TypeCheck(pImplicitCastExpr->getSubExprAsWritten()->getType()).Class("VclPtr")
 696         .GlobalNamespace())
 697     {
 698         return true;
 699     }
 700     report(
 701         DiagnosticsEngine::Warning,
 702         "calling delete on instance of VclPtr, must rather call disposeAndClear()",
 703         pCXXDeleteExpr->getBeginLoc())
 704      << pCXXDeleteExpr->getSourceRange();
 705     return true;
 706 }
 707
 708
 709 /**
 710 The AST looks like:
 711 `-CXXMemberCallExpr 0xb06d8b0 'void'
 712   `-MemberExpr 0xb06d868 '<bound member function type>' ->dispose 0x9d34880
 713     `-ImplicitCastExpr 0xb06d8d8 'class SfxTabPage *' <UncheckedDerivedToBase (SfxTabPage)>
 714       `-CXXThisExpr 0xb06d850 'class SfxAcceleratorConfigPage *' this
 715
 716 */
 717 bool VCLWidgets::isDisposeCallingSuperclassDispose(const CXXMethodDecl* pMethodDecl)
 718 {
 719     const CompoundStmt *pCompoundStatement = dyn_cast<CompoundStmt>(pMethodDecl->getBody());
 720     if (!pCompoundStatement) return false;
 721     if (pCompoundStatement->size() == 0) return false;
 722     // find the last statement
 723     const CXXMemberCallExpr *pCallExpr = dyn_cast<CXXMemberCallExpr>(*pCompoundStatement->body_rbegin());
 724     if (!pCallExpr) return false;
 725     const MemberExpr *pMemberExpr = dyn_cast<MemberExpr>(pCallExpr->getCallee());
 726     if (!pMemberExpr) return false;
 727     if (!loplugin::DeclCheck(pMemberExpr->getMemberDecl()).Function("dispose")) return false;
 728     const CXXMethodDecl *pDirectCallee = dyn_cast<CXXMethodDecl>(pCallExpr->getDirectCallee());
 729     if (!pDirectCallee) return false;
 730 /* Not working yet. Partially because sometimes the superclass does not a dispose() method, so it gets passed up the chain.
 731    Need complex checking for that case.
 732     if (pDirectCallee->getParent()->getTypeForDecl() != (*pMethodDecl->getParent()->bases_begin()).getType().getTypePtr()) {
 733         report(
 734             DiagnosticsEngine::Warning,
 735             "dispose() method calling wrong baseclass, calling " + pDirectCallee->getParent()->getQualifiedNameAsString() +
 736             " should be calling " + (*pMethodDecl->getParent()->bases_begin()).getType().getAsString(),
 737             pCallExpr->getLocStart())
 738           << pCallExpr->getSourceRange();
 739         return false;
 740     }*/
 741     return true;
 742 }
 743
 744 bool containsVclPtr(const clang::Type* pType0);
 745
 746 bool containsVclPtr(const QualType& qType) {
 747     auto check = loplugin::TypeCheck(qType);
 748     if (check.Class("ScopedVclPtr").GlobalNamespace()
 749         || check.Class("ScopedVclPtrInstance").GlobalNamespace()
 750         || check.Class("VclPtr").GlobalNamespace()
 751         || check.Class("VclPtrInstance").GlobalNamespace())
 752     {
 753         return true;
 754     }
 755     return containsVclPtr(qType.getTypePtr());
 756 }
 757
 758 bool containsVclPtr(const clang::Type* pType0) {
 759     if (!pType0)
 760         return false;
 761     const clang::Type* pType = pType0->getUnqualifiedDesugaredType();
 762     if (!pType)
 763         return false;
 764     if (pType->isPointerType()) {
 765         return false;
 766     } else if (pType->isArrayType()) {
 767         const clang::ArrayType* pArrayType = dyn_cast<clang::ArrayType>(pType);
 768         QualType elementType = pArrayType->getElementType();
 769         return containsVclPtr(elementType);
 770     } else {
 771         const CXXRecordDecl* pRecordDecl = pType->getAsCXXRecordDecl();
 772         if (pRecordDecl)
 773         {
 774             auto check = loplugin::DeclCheck(pRecordDecl);
 775             if (check.Class("ScopedVclPtr").GlobalNamespace()
 776                 || check.Class("ScopedVclPtrInstance").GlobalNamespace()
 777                 || check.Class("VclPtr").GlobalNamespace()
 778                 || check.Class("VclPtrInstance").GlobalNamespace())
 779             {
 780                 return true;
 781             }
 782             for(auto fieldDecl = pRecordDecl->field_begin();
 783                 fieldDecl != pRecordDecl->field_end(); ++fieldDecl)
 784             {
 785                 const RecordType *pFieldRecordType = fieldDecl->getType()->getAs<RecordType>();
 786                 if (pFieldRecordType && containsVclPtr(pFieldRecordType)) {
 787                     return true;
 788                 }
 789             }
 790             for(auto baseSpecifier = pRecordDecl->bases_begin();
 791                 baseSpecifier != pRecordDecl->bases_end(); ++baseSpecifier)
 792             {
 793                 const RecordType *pFieldRecordType = baseSpecifier->getType()->getAs<RecordType>();
 794                 if (pFieldRecordType && containsVclPtr(pFieldRecordType)) {
 795                     return true;
 796                 }
 797             }
 798         }
 799     }
 800     return false;
 801 }
 802
 803 bool VCLWidgets::VisitCallExpr(const CallExpr* pCallExpr)
 804 {
 805     if (ignoreLocation(pCallExpr)) {
 806         return true;
 807     }
 808     FunctionDecl const * fdecl = pCallExpr->getDirectCallee();
 809     if (fdecl == nullptr) {
 810         return true;
 811     }
 812     std::string qname { fdecl->getQualifiedNameAsString() };
 813     if (qname.find("memcpy") == std::string::npos
 814          && qname.find("bcopy") == std::string::npos
 815          && qname.find("memmove") == std::string::npos
 816          && qname.find("rtl_copy") == std::string::npos) {
 817         return true;
 818     }
 819     mbCheckingMemcpy = true;
 820     Stmt * pStmt = const_cast<Stmt*>(static_cast<const Stmt*>(pCallExpr->getArg(0)));
 821     TraverseStmt(pStmt);
 822     mbCheckingMemcpy = false;
 823     return true;
 824 }
 825
 826 bool VCLWidgets::VisitDeclRefExpr(const DeclRefExpr* pDeclRefExpr)
 827 {
 828     if (!mbCheckingMemcpy) {
 829         return true;
 830     }
 831     if (ignoreLocation(pDeclRefExpr)) {
 832         return true;
 833     }
 834     QualType pType = pDeclRefExpr->getDecl()->getType();
 835     if (pType->isPointerType()) {
 836         pType = pType->getPointeeType();
 837     }
 838     if (!containsVclPtr(pType)) {
 839         return true;
 840     }
 841     report(
 842         DiagnosticsEngine::Warning,
 843         "Calling memcpy on a type which contains a VclPtr",
 844         pDeclRefExpr->getExprLoc());
 845     return true;
 846 }
 847
 848 bool VCLWidgets::VisitCXXConstructExpr( const CXXConstructExpr* constructExpr )
 849 {
 850     if (ignoreLocation(constructExpr)) {
 851         return true;
 852     }
 853     if (constructExpr->getConstructionKind() != compat::CXXConstructionKind::Complete) {
 854         return true;
 855     }
 856     const CXXConstructorDecl* pConstructorDecl = constructExpr->getConstructor();
 857     const CXXRecordDecl* recordDecl = pConstructorDecl->getParent();
 858     if (isDerivedFromVclReferenceBase(recordDecl)) {
 859         StringRef aFileName = getFilenameOfLocation(
 860             compiler.getSourceManager().getSpellingLoc(constructExpr->getBeginLoc()));
 861         if (!loplugin::isSamePathname(aFileName, SRCDIR "/include/vcl/vclptr.hxx")) {
 862             report(
 863                 DiagnosticsEngine::Warning,
 864                 "Calling constructor of a VclReferenceBase-derived type directly; all such creation should go via VclPtr<>::Create",
 865                 constructExpr->getExprLoc());
 866         }
 867     }
 868     return true;
 869 }
 870
 871 loplugin::Plugin::Registration< VCLWidgets > vclwidgets("vclwidgets");
 872
 873 }
 874
 875 // Cannot be shared, uses TraverseStmt().
 876
 877 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */