compilerplugins/clang/fragiledestructor.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 #ifndef LO_CLANG_SHARED_PLUGINS
  10
  11 #include <string>
  12 #include <iostream>
  13
  14 #include "plugin.hxx"
  15 #include "config_clang.h"
  16 #include "clang/AST/CXXInheritance.h"
  17
  18
  19 // Check for calls to virtual methods from destructors. These are dangerous because intention might be to call
  20 // a method on a subclass, while in actual fact, it only calls the method on the current or super class.
  21 //
  22
  23 namespace {
  24
  25 class FragileDestructor:
  26     public loplugin::FilteringPlugin<FragileDestructor>
  27 {
  28 public:
  29     explicit FragileDestructor(loplugin::InstantiationData const & data):
  30         FilteringPlugin(data) {}
  31
  32     virtual bool preRun() override
  33     {
  34         StringRef fn(handler.getMainFileName());
  35
  36         // TODO, these all need fixing
  37
  38         if (loplugin::isSamePathname(fn, SRCDIR "/comphelper/source/misc/proxyaggregation.cxx"))
  39              return false;
  40         if (loplugin::isSamePathname(fn, SRCDIR "/svx/source/svdraw/svdpntv.cxx")) // ~SdrPaintView calling ClearPageView
  41              return false;
  42         if (loplugin::isSamePathname(fn, SRCDIR "/svx/source/svdraw/svdobj.cxx")) // ~SdrObject calling GetLastBoundRect
  43              return false;
  44         if (loplugin::isSamePathname(fn, SRCDIR "/svx/source/svdraw/svdedxv.cxx")) // ~SdrObjEditView calling SdrEndTextEdit
  45              return false;
  46         if (loplugin::isSamePathname(fn, SRCDIR "/connectivity/source/drivers/file/FStatement.cxx")) // ~OStatement_Base calling disposing
  47              return false;
  48         if (loplugin::isSamePathname(fn, SRCDIR "/sd/source/core/CustomAnimationEffect.cxx")) // ~EffectSequenceHelper calling reset
  49              return false;
  50         if (loplugin::isSamePathname(fn, SRCDIR "/sd/source/ui/view/sdview.cxx")) // ~View calling DeleteWindowFromPaintView
  51              return false;
  52         if (loplugin::isSamePathname(fn, SRCDIR "/sw/source/core/layout/ssfrm.cxx")) // ~SwFrame calling IsDeleteForbidden
  53              return false;
  54         if (loplugin::isSamePathname(fn, SRCDIR "/chart2/source/model/template/CandleStickChartType.cxx")) // to ignore <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100797> "[10/11/12 Regression] using declaration causing virtual call with wrongly adjusted this pointer" workaround
  55              return false;
  56
  57         return true;
  58     }
  59
  60     virtual void run() override
  61     {
  62         if (preRun())
  63             TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
  64     }
  65
  66     bool PreTraverseCXXDestructorDecl(CXXDestructorDecl*);
  67     bool PostTraverseCXXDestructorDecl(CXXDestructorDecl*, bool);
  68     bool TraverseCXXDestructorDecl(CXXDestructorDecl*);
  69     bool VisitCXXMemberCallExpr(const CXXMemberCallExpr *);
  70
  71 private:
  72     std::vector<CXXDestructorDecl*>  m_vDestructors;
  73 };
  74
  75 bool FragileDestructor::PreTraverseCXXDestructorDecl(CXXDestructorDecl* cxxDestructorDecl)
  76 {
  77     if (ignoreLocation(cxxDestructorDecl))
  78         return true;
  79     if (!cxxDestructorDecl->isThisDeclarationADefinition())
  80         return true;
  81     if (cxxDestructorDecl->getParent()->hasAttr<FinalAttr>())
  82         return true;
  83     m_vDestructors.push_back(cxxDestructorDecl);
  84     return true;
  85 }
  86
  87 bool FragileDestructor::PostTraverseCXXDestructorDecl(CXXDestructorDecl* cxxDestructorDecl, bool)
  88 {
  89     if (!m_vDestructors.empty() && m_vDestructors.back() == cxxDestructorDecl)
  90         m_vDestructors.pop_back();
  91     return true;
  92 }
  93
  94 bool FragileDestructor::TraverseCXXDestructorDecl(CXXDestructorDecl* cxxDestructorDecl)
  95 {
  96     PreTraverseCXXDestructorDecl(cxxDestructorDecl);
  97     auto ret = FilteringPlugin::TraverseCXXDestructorDecl(cxxDestructorDecl);
  98     PostTraverseCXXDestructorDecl(cxxDestructorDecl, ret);
  99     return ret;
 100 }
 101
 102 bool FragileDestructor::VisitCXXMemberCallExpr(const CXXMemberCallExpr* callExpr)
 103 {
 104     if (m_vDestructors.empty() || ignoreLocation(callExpr))
 105         return true;
 106     const CXXMethodDecl* methodDecl = callExpr->getMethodDecl();
 107     if (!methodDecl->isVirtual() || methodDecl->hasAttr<FinalAttr>())
 108         return true;
 109     const CXXRecordDecl* parentRecordDecl = methodDecl->getParent();
 110     if (parentRecordDecl->hasAttr<FinalAttr>())
 111         return true;
 112     if (!callExpr->getImplicitObjectArgument()->IgnoreImpCasts()->isImplicitCXXThis())
 113         return true;
 114
 115     // if we see an explicit call to its own method, that's OK
 116     auto s1 = compiler.getSourceManager().getCharacterData(callExpr->getBeginLoc());
 117     auto s2 = compiler.getSourceManager().getCharacterData(callExpr->getEndLoc());
 118     std::string tok(s1, s2-s1);
 119     if (tok.find("::") != std::string::npos)
 120         return true;
 121
 122     // Very common pattern that we call acquire/dispose in destructors of UNO objects
 123     // to make sure they are cleaned up.
 124     if (methodDecl->getName() == "acquire" || methodDecl->getName() == "dispose")
 125         return true;
 126
 127     report(
 128         DiagnosticsEngine::Warning,
 129         "calling virtual method from destructor, either make the virtual method final, or make this class final",
 130         callExpr->getBeginLoc())
 131       << callExpr->getSourceRange();
 132     report(
 133         DiagnosticsEngine::Note,
 134         "callee method here",
 135         methodDecl->getBeginLoc())
 136       << methodDecl->getSourceRange();
 137     return true;
 138 }
 139
 140
 141 loplugin::Plugin::Registration<FragileDestructor> fragiledestructor("fragiledestructor");
 142
 143 }
 144
 145 #endif // LO_CLANG_SHARED_PLUGINS
 146
 147 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */