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
  10 #include <string>
  11 #include <iostream>
  12
  13 #include "plugin.hxx"
  14 #include "compat.hxx"
  15 #include "clang/AST/CXXInheritance.h"
  16
  17
  18 // Check for calls to virtual methods from destructors. These are dangerous because intention might be to call
  19 // a method on a subclass, while in actual fact, it only calls the method on the current or super class.
  20 //
  21
  22 namespace {
  23
  24 class FragileDestructor:
  25     public loplugin::FilteringPlugin<FragileDestructor>
  26 {
  27 public:
  28     explicit FragileDestructor(loplugin::InstantiationData const & data):
  29         FilteringPlugin(data) {}
  30
  31     virtual void run() override { TraverseDecl(compiler.getASTContext().getTranslationUnitDecl()); }
  32
  33     bool TraverseCXXDestructorDecl(CXXDestructorDecl *);
  34
  35     bool VisitCXXMemberCallExpr(const CXXMemberCallExpr *);
  36
  37 private:
  38     bool mbChecking = false;
  39 };
  40
  41 bool FragileDestructor::TraverseCXXDestructorDecl(CXXDestructorDecl* pCXXDestructorDecl)
  42 {
  43     if (ignoreLocation(pCXXDestructorDecl)) {
  44         return RecursiveASTVisitor::TraverseCXXDestructorDecl(pCXXDestructorDecl);
  45     }
  46     if (!pCXXDestructorDecl->isThisDeclarationADefinition()) {
  47         return RecursiveASTVisitor::TraverseCXXDestructorDecl(pCXXDestructorDecl);
  48     }
  49     // ignore this for now, too tricky for me to work out
  50     StringRef aFileName = getFileNameOfSpellingLoc(
  51             compiler.getSourceManager().getSpellingLoc(compat::getBeginLoc(pCXXDestructorDecl)));
  52     if (loplugin::hasPathnamePrefix(aFileName, SRCDIR "/include/comphelper/")
  53         || loplugin::hasPathnamePrefix(aFileName, SRCDIR "/include/cppuhelper/")
  54         || loplugin::hasPathnamePrefix(aFileName, SRCDIR "/cppuhelper/")
  55         || loplugin::hasPathnamePrefix(aFileName, SRCDIR "/comphelper/")
  56         // don't know how to detect this in clang - it is making an explicit call to its own method, so presumably OK
  57         || loplugin::isSamePathname(aFileName, SRCDIR "/basic/source/sbx/sbxvalue.cxx")
  58        )
  59         return RecursiveASTVisitor::TraverseCXXDestructorDecl(pCXXDestructorDecl);
  60     mbChecking = true;
  61     bool ret = RecursiveASTVisitor::TraverseCXXDestructorDecl(pCXXDestructorDecl);
  62     mbChecking = false;
  63     return ret;
  64 }
  65
  66 bool FragileDestructor::VisitCXXMemberCallExpr(const CXXMemberCallExpr* callExpr)
  67 {
  68     if (!mbChecking || ignoreLocation(callExpr)) {
  69         return true;
  70     }
  71     const CXXMethodDecl* methodDecl = callExpr->getMethodDecl();
  72     if (!methodDecl->isVirtual() || methodDecl->hasAttr<FinalAttr>()) {
  73         return true;
  74     }
  75     const CXXRecordDecl* parentRecordDecl = methodDecl->getParent();
  76     if (parentRecordDecl->hasAttr<FinalAttr>()) {
  77         return true;
  78     }
  79     if (!callExpr->getImplicitObjectArgument()->IgnoreImpCasts()->isImplicitCXXThis()) {
  80         return true;
  81     }
  82     // if we see an explicit call to its own method, that's OK
  83     auto s1 = compiler.getSourceManager().getCharacterData(compat::getBeginLoc(callExpr));
  84     auto s2 = compiler.getSourceManager().getCharacterData(compat::getEndLoc(callExpr));
  85     std::string tok(s1, s2-s1);
  86     if (tok.find("::") != std::string::npos) {
  87         return true;
  88     }
  89     // e.g. osl/thread.hxx and cppuhelper/compbase.hxx
  90     StringRef aFileName = getFileNameOfSpellingLoc(
  91         compiler.getSourceManager().getSpellingLoc(compat::getBeginLoc(methodDecl)));
  92     if (loplugin::hasPathnamePrefix(aFileName, SRCDIR "/include/osl/")
  93         || loplugin::hasPathnamePrefix(aFileName, SRCDIR "/include/comphelper/")
  94         || loplugin::hasPathnamePrefix(aFileName, SRCDIR "/include/cppuhelper/"))
  95         return true;
  96     report(
  97         DiagnosticsEngine::Warning,
  98         "calling virtual method from destructor, either make the virtual method final, or make this class final",
  99         compat::getBeginLoc(callExpr))
 100       << callExpr->getSourceRange();
 101     report(
 102         DiagnosticsEngine::Note,
 103         "callee method here",
 104         compat::getBeginLoc(methodDecl))
 105       << methodDecl->getSourceRange();
 106     return true;
 107 }
 108
 109
 110 loplugin::Plugin::Registration< FragileDestructor > X("fragiledestructor", false);
 111
 112 }
 113
 114 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */