compilerplugins/clang/unnecessarylocking.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 <fstream>
  14 #include <set>
  15 #include <unordered_set>
  16
  17 #include <clang/AST/CXXInheritance.h>
  18
  19 #include "config_clang.h"
  20
  21 #include "plugin.hxx"
  22 #include "check.hxx"
  23
  24 /**
  25 Look for methods that are taking a lock at the top of the method, but then not
  26 touching any object-local state. In which case the method might not need locking.
  27
  28 TODO
  29
  30 (*) check if the data being returned is never modified, in which case locking is not necessary
  31
  32 */
  33
  34 namespace
  35 {
  36 class UnnecessaryLocking : public loplugin::FilteringPlugin<UnnecessaryLocking>
  37 {
  38 public:
  39     explicit UnnecessaryLocking(loplugin::InstantiationData const& data)
  40         : FilteringPlugin(data)
  41     {
  42     }
  43
  44     virtual bool preRun() override
  45     {
  46         //        StringRef fn(handler.getMainFileName());
  47         //        if (loplugin::isSamePathname(fn, WORKDIR "/YaccTarget/unoidl/source/sourceprovider-parser.cxx"))
  48         //            return false;
  49         return true;
  50     }
  51     virtual void run() override
  52     {
  53         if (preRun())
  54             TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
  55     }
  56
  57     bool VisitCompoundStmt(const CompoundStmt*);
  58     bool VisitCXXThisExpr(const CXXThisExpr*);
  59     bool VisitCallExpr(const CallExpr*);
  60
  61 private:
  62     bool isSolarMutexLockGuardStmt(const Stmt*);
  63     const CXXThisExpr* isOtherMutexLockGuardStmt(const Stmt*);
  64     std::vector<bool> m_TouchesThis;
  65     // so we ignore the CxxThisEpxr that references the maMutex in the guard expression
  66     std::vector<const CXXThisExpr*> m_IgnoreThis;
  67 };
  68
  69 bool UnnecessaryLocking::VisitCompoundStmt(const CompoundStmt* compoundStmt)
  70 {
  71     if (ignoreLocation(compoundStmt))
  72         return true;
  73     if (compoundStmt->size() < 1)
  74         return true;
  75
  76     const Stmt* firstStmt = *compoundStmt->body_begin();
  77     bool solarMutex = isSolarMutexLockGuardStmt(firstStmt);
  78     const CXXThisExpr* ignoreThisStmt = nullptr;
  79     if (!solarMutex)
  80         ignoreThisStmt = isOtherMutexLockGuardStmt(firstStmt);
  81     if (!solarMutex && ignoreThisStmt == nullptr)
  82         return true;
  83
  84     m_TouchesThis.push_back(false);
  85     m_IgnoreThis.push_back(ignoreThisStmt);
  86
  87     for (const Stmt* stmt : compoundStmt->body())
  88         FilteringPlugin::TraverseStmt(const_cast<Stmt*>(stmt));
  89
  90     if (!m_TouchesThis.back())
  91     {
  92         StringRef fn = getFilenameOfLocation(
  93             compiler.getSourceManager().getSpellingLoc(compoundStmt->getBeginLoc()));
  94         if (
  95             // template magic
  96             !loplugin::isSamePathname(fn, SRCDIR "/include/comphelper/unique_disposing_ptr.hxx")
  97             && !loplugin::isSamePathname(fn, SRCDIR "/sw/inc/unobaseclass.hxx")
  98
  99             // false+
 100             && !loplugin::isSamePathname(fn, SRCDIR "/cppuhelper/source/component_context.cxx")
 101             && !loplugin::isSamePathname(fn, SRCDIR "/toolkit/source/controls/tree/treecontrol.cxx")
 102             && !loplugin::isSamePathname(fn,
 103                                          SRCDIR "/toolkit/source/helper/listenermultiplexer.cxx")
 104             && !loplugin::isSamePathname(fn, SRCDIR "/include/toolkit/helper/macros.hxx")
 105             && !loplugin::isSamePathname(fn, SRCDIR
 106                                          "/chart2/source/controller/main/CommandDispatch.cxx")
 107             && !loplugin::isSamePathname(fn, SRCDIR "/chart2/source/controller/main/ChartView.cxx")
 108             && !loplugin::isSamePathname(fn, SRCDIR
 109                                          "/chart2/source/controller/main/SelectionHelper.cxx")
 110             && !loplugin::isSamePathname(
 111                    fn, SRCDIR "/chart2/source/controller/accessibility/AccessibleChartView.cxx")
 112             && !loplugin::isSamePathname(fn, SRCDIR "/desktop/source/offacc/acceptor.cxx")
 113             && !loplugin::isSamePathname(
 114                    fn, SRCDIR "/desktop/source/deployment/registry/component/dp_component.cxx")
 115             && !loplugin::isSamePathname(fn,
 116                                          SRCDIR "/desktop/source/deployment/gui/dp_gui_dialog2.cxx")
 117             && !loplugin::isSamePathname(fn, SRCDIR "/desktop/source/lib/init.cxx")
 118             && !loplugin::isSamePathname(
 119                    fn, SRCDIR "/sd/source/ui/slidesorter/cache/SlsCacheConfiguration.cxx")
 120
 121             // needs to lock around access to methods in vcl
 122             && !loplugin::isSamePathname(fn, SRCDIR "/basctl/source/basicide/unomodel.cxx")
 123             && !loplugin::isSamePathname(fn, SRCDIR "/cui/source/dialogs/AdditionsDialog.cxx")
 124             && !loplugin::isSamePathname(fn, SRCDIR "/cui/source/dialogs/cuigaldlg.cxx")
 125             && !loplugin::isSamePathname(fn, SRCDIR "/dbaccess/source/ui/browser/unodatbr.cxx")
 126             && !loplugin::isSamePathname(fn, SRCDIR "/dbaccess/source/ui/uno/dbinteraction.cxx")
 127             && !loplugin::isSamePathname(fn, SRCDIR "/dbaccess/source/ui/dlg/DbAdminImpl.cxx")
 128             && !loplugin::isSamePathname(fn, SRCDIR "/dbaccess/source/ui/misc/UITools.cxx")
 129             && !loplugin::isSamePathname(fn, SRCDIR "/desktop/source/lib/lokclipboard.cxx")
 130             && !loplugin::isSamePathname(fn, SRCDIR "/editeng/source/misc/unolingu.cxx")
 131             && !loplugin::isSamePathname(fn, SRCDIR
 132                                          "/framework/source/uielement/popuptoolbarcontroller.cxx")
 133             && !loplugin::isSamePathname(fn,
 134                                          SRCDIR "/framework/source/uielement/newmenucontroller.cxx")
 135             && !loplugin::isSamePathname(fn,
 136                                          SRCDIR "/framework/source/uielement/menubarwrapper.cxx")
 137             && !loplugin::isSamePathname(fn, SRCDIR "/framework/source/services/desktop.cxx")
 138             && !loplugin::isSamePathname(fn,
 139                                          SRCDIR "/framework/source/layoutmanager/layoutmanager.cxx")
 140             && !loplugin::isSamePathname(fn, SRCDIR
 141                                          "/framework/source/layoutmanager/toolbarlayoutmanager.cxx")
 142             && !loplugin::isSamePathname(fn, SRCDIR
 143                                          "/framework/source/fwe/helper/actiontriggerhelper.cxx")
 144             && !loplugin::isSamePathname(fn, SRCDIR "/sc/source/ui/unoobj/unodoc.cxx")
 145             && !loplugin::isSamePathname(fn, SRCDIR "/sc/source/ui/unoobj/filtuno.cxx")
 146             && !loplugin::isSamePathname(fn, SRCDIR "/sc/source/ui/unoobj/funcuno.cxx")
 147             && !loplugin::isSamePathname(fn, SRCDIR "/sc/source/ui/vba/vbaapplication.cxx")
 148             && !loplugin::isSamePathname(fn, SRCDIR "/sd/source/ui/unoidl/unodoc.cxx")
 149             && !loplugin::isSamePathname(fn, SRCDIR "/sd/source/ui/unoidl/unomodule.cxx")
 150             && !loplugin::isSamePathname(fn, SRCDIR "/sd/source/ui/remotecontrol/Receiver.cxx")
 151             && !loplugin::isSamePathname(fn, SRCDIR
 152                                          "/sd/source/ui/slidesorter/controller/SlsClipboard.cxx")
 153             && !loplugin::isSamePathname(fn, SRCDIR "/sfx2/source/appl/fwkhelper.cxx")
 154             && !loplugin::isSamePathname(fn, SRCDIR "/sfx2/source/appl/appinit.cxx")
 155             && !loplugin::isSamePathname(fn, SRCDIR "/sfx2/source/appl/shutdownicon.cxx")
 156             && !loplugin::isSamePathname(fn, SRCDIR "/sfx2/source/dialog/dockwin.cxx")
 157             && !loplugin::isSamePathname(fn, SRCDIR "/sfx2/source/statbar/stbitem.cxx")
 158             && !loplugin::isSamePathname(fn, SRCDIR "/sfx2/source/toolbox/tbxitem.cxx")
 159             && !loplugin::isSamePathname(fn,
 160                                          SRCDIR "/svtools/source/java/javainteractionhandler.cxx")
 161             && !loplugin::isSamePathname(fn,
 162                                          SRCDIR "/svx/source/accessibility/ShapeTypeHandler.cxx")
 163             && !loplugin::isSamePathname(fn,
 164                                          SRCDIR "/svx/source/tbxctrls/tbunosearchcontrollers.cxx")
 165             && !loplugin::isSamePathname(fn, SRCDIR "/svx/source/form/fmscriptingenv.cxx")
 166             && !loplugin::isSamePathname(fn, SRCDIR "/svx/source/fmcomp/fmgridif.cxx")
 167             && !loplugin::isSamePathname(fn, SRCDIR "/toolkit/source/awt/vclxspinbutton.cxx")
 168             && !loplugin::isSamePathname(fn, SRCDIR "/toolkit/source/awt/vclxtoolkit.cxx")
 169             && !loplugin::isSamePathname(fn,
 170                                          SRCDIR "/toolkit/source/controls/tree/treecontrolpeer.cxx")
 171             && !loplugin::isSamePathname(fn, SRCDIR "/ucb/source/ucp/image/ucpimage.cxx")
 172             && !loplugin::hasPathnamePrefix(fn, SRCDIR "/vcl/")
 173
 174             // not sure
 175             && !loplugin::isSamePathname(fn,
 176                                          SRCDIR "/dbaccess/source/ui/browser/AsynchronousLink.cxx")
 177             && !loplugin::isSamePathname(fn, SRCDIR "/framework/source/services/autorecovery.cxx")
 178             && !loplugin::isSamePathname(fn, SRCDIR "/sfx2/source/dialog/filedlghelper.cxx")
 179             && !loplugin::isSamePathname(fn, SRCDIR "/sfx2/source/appl/appdispatchprovider.cxx")
 180             && !loplugin::isSamePathname(fn, SRCDIR "/ucb/source/ucp/tdoc/tdoc_storage.cxx")
 181             && !loplugin::isSamePathname(fn, SRCDIR "/sc/source/core/data/poolhelp.cxx")
 182
 183             // touching shared global data
 184             && !loplugin::isSamePathname(fn, SRCDIR
 185                                          "/framework/source/fwi/classes/protocolhandlercache.cxx")
 186             && !loplugin::isSamePathname(fn,
 187                                          SRCDIR "/basic/source/basmgr/basicmanagerrepository.cxx")
 188             && !loplugin::isSamePathname(fn, SRCDIR "/basic/source/classes/sb.cxx")
 189             && !loplugin::isSamePathname(fn, SRCDIR "/sc/source/ui/unoobj/docuno.cxx")
 190             && !loplugin::isSamePathname(fn, SRCDIR "/sc/source/ui/unoobj/afmtuno.cxx")
 191             && !loplugin::isSamePathname(fn, SRCDIR "/sc/source/ui/unoobj/appluno.cxx")
 192             && !loplugin::isSamePathname(fn, SRCDIR "/sc/source/ui/vba/vbaapplication.cxx")
 193             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/core/access/accdoc.cxx")
 194             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/core/access/acccontext.cxx")
 195             && !loplugin::isSamePathname(fn,
 196                                          SRCDIR "/sw/source/core/bastyp/proofreadingiterator.cxx")
 197             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/core/unocore/unoftn.cxx")
 198             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/core/unocore/unolinebreak.cxx")
 199             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/core/unocore/unoobj.cxx")
 200             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/core/unocore/unorefmk.cxx")
 201             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/core/unocore/unotbl.cxx")
 202             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/core/unocore/unocontentcontrol.cxx")
 203             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/core/unocore/unobkm.cxx")
 204             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/core/unocore/unocoll.cxx")
 205             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/core/unocore/unostyle.cxx")
 206             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/filter/xml/xmltexti.cxx")
 207             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/uibase/uno/dlelstnr.cxx")
 208             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/uibase/uno/unoatxt.cxx")
 209             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/uibase/uno/unodoc.cxx")
 210             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/uibase/uno/unomodule.cxx")
 211             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/uibase/uno/SwXFilterOptions.cxx")
 212             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/uibase/shells/translatehelper.cxx")
 213             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/ui/vba/vbaapplication.cxx")
 214             && !loplugin::isSamePathname(fn, SRCDIR "/unoxml/source/dom/documentbuilder.cxx")
 215             && !loplugin::isSamePathname(
 216                    fn, SRCDIR "/sd/source/ui/accessibility/AccessibleDrawDocumentView.cxx")
 217             && !loplugin::isSamePathname(fn, SRCDIR "/starmath/source/accessibility.cxx")
 218             && !loplugin::isSamePathname(fn,
 219                                          SRCDIR "/starmath/source/AccessibleSmElementsControl.cxx"))
 220         {
 221             report(DiagnosticsEngine::Warning, "unnecessary locking", compoundStmt->getBeginLoc())
 222                 << compoundStmt->getSourceRange();
 223         }
 224     }
 225
 226     m_TouchesThis.pop_back();
 227     m_IgnoreThis.pop_back();
 228
 229     return true;
 230 }
 231
 232 bool UnnecessaryLocking::isSolarMutexLockGuardStmt(const Stmt* stmt)
 233 {
 234     auto declStmt = dyn_cast<DeclStmt>(stmt);
 235     if (!declStmt)
 236         return false;
 237     if (!declStmt->isSingleDecl())
 238         return false;
 239     auto varDecl = dyn_cast<VarDecl>(declStmt->getSingleDecl());
 240     if (!varDecl)
 241         return false;
 242     auto tc = loplugin::TypeCheck(varDecl->getType());
 243     if (!tc.Class("SolarMutexGuard").GlobalNamespace()
 244         && !tc.Class("SolarMutexClearableGuard").GlobalNamespace()
 245         && !tc.Class("SolarMutexResettableGuard").GlobalNamespace()
 246         && !tc.Class("SolarMutexTryAndBuyGuard").GlobalNamespace())
 247         return false;
 248     return true;
 249 }
 250
 251 const CXXThisExpr* UnnecessaryLocking::isOtherMutexLockGuardStmt(const Stmt* stmt)
 252 {
 253     auto declStmt = dyn_cast<DeclStmt>(stmt);
 254     if (!declStmt)
 255         return nullptr;
 256     if (!declStmt->isSingleDecl())
 257         return nullptr;
 258     auto varDecl = dyn_cast<VarDecl>(declStmt->getSingleDecl());
 259     if (!varDecl)
 260         return nullptr;
 261     auto tc = loplugin::TypeCheck(varDecl->getType());
 262     if (!tc.Class("unique_lock").StdNamespace() && !tc.Class("scoped_lock").StdNamespace()
 263         && !tc.Class("Guard") && !tc.Class("ClearableGuard") && !tc.Class("ResettableGuard"))
 264         return nullptr;
 265     auto cxxConstructExpr = dyn_cast<CXXConstructExpr>(varDecl->getInit());
 266     if (!cxxConstructExpr || cxxConstructExpr->getNumArgs() < 1)
 267         return nullptr;
 268     auto arg0 = cxxConstructExpr->getArg(0);
 269     if (auto memberExpr = dyn_cast<MemberExpr>(arg0))
 270     {
 271         const CXXThisExpr* thisStmt
 272             = dyn_cast<CXXThisExpr>(memberExpr->getBase()->IgnoreImplicit());
 273         return thisStmt;
 274     }
 275     else if (auto memberCallExpr = dyn_cast<CXXMemberCallExpr>(arg0))
 276     {
 277         return dyn_cast_or_null<CXXThisExpr>(
 278             memberCallExpr->getImplicitObjectArgument()->IgnoreImplicit());
 279     }
 280     return nullptr;
 281 }
 282
 283 bool UnnecessaryLocking::VisitCXXThisExpr(const CXXThisExpr* cxxThisExpr)
 284 {
 285     if (ignoreLocation(cxxThisExpr))
 286         return true;
 287     // just in case
 288     if (m_TouchesThis.empty())
 289         return true;
 290     // already found something
 291     if (m_TouchesThis.back())
 292         return true;
 293     if (m_IgnoreThis.back() && m_IgnoreThis.back() == cxxThisExpr)
 294         return true;
 295     m_TouchesThis.back() = true;
 296     return true;
 297 }
 298
 299 bool UnnecessaryLocking::VisitCallExpr(const CallExpr* callExpr)
 300 {
 301     if (ignoreLocation(callExpr))
 302         return true;
 303     // just in case
 304     if (m_TouchesThis.empty())
 305         return true;
 306     // already found something
 307     if (m_TouchesThis.back())
 308         return true;
 309     const CXXMethodDecl* callee = dyn_cast_or_null<CXXMethodDecl>(callExpr->getDirectCallee());
 310     if (!callee)
 311         return true;
 312     auto dc = loplugin::DeclCheck(callee->getParent());
 313     if (dc.Class("VCLUnoHelper") || dc.Class("Application"))
 314         m_TouchesThis.back() = true;
 315     return true;
 316 }
 317
 318 /** off by default because each warning needs to be carefully inspected */
 319 loplugin::Plugin::Registration<UnnecessaryLocking> unnecessarylocking("unnecessarylocking", false);
 320 }
 321
 322 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */