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
 119             // needs to lock around access to methods in vcl
 120             && !loplugin::isSamePathname(fn, SRCDIR "/basctl/source/basicide/unomodel.cxx")
 121             && !loplugin::isSamePathname(fn, SRCDIR "/cui/source/dialogs/AdditionsDialog.cxx")
 122             && !loplugin::isSamePathname(fn, SRCDIR "/cui/source/dialogs/cuigaldlg.cxx")
 123             && !loplugin::isSamePathname(fn, SRCDIR "/dbaccess/source/ui/browser/unodatbr.cxx")
 124             && !loplugin::isSamePathname(fn, SRCDIR "/dbaccess/source/ui/uno/dbinteraction.cxx")
 125             && !loplugin::isSamePathname(fn, SRCDIR "/dbaccess/source/ui/dlg/DbAdminImpl.cxx")
 126             && !loplugin::isSamePathname(fn, SRCDIR "/dbaccess/source/ui/misc/UITools.cxx")
 127             && !loplugin::isSamePathname(fn, SRCDIR "/desktop/source/lib/lokclipboard.cxx")
 128             && !loplugin::isSamePathname(fn, SRCDIR "/editeng/source/misc/unolingu.cxx")
 129             && !loplugin::isSamePathname(fn, SRCDIR
 130                                          "/framework/source/uielement/popuptoolbarcontroller.cxx")
 131             && !loplugin::isSamePathname(fn,
 132                                          SRCDIR "/framework/source/uielement/newmenucontroller.cxx")
 133             && !loplugin::isSamePathname(fn,
 134                                          SRCDIR "/framework/source/uielement/menubarwrapper.cxx")
 135             && !loplugin::isSamePathname(fn, SRCDIR "/framework/source/services/desktop.cxx")
 136             && !loplugin::isSamePathname(fn,
 137                                          SRCDIR "/framework/source/layoutmanager/layoutmanager.cxx")
 138             && !loplugin::isSamePathname(fn, SRCDIR
 139                                          "/framework/source/layoutmanager/toolbarlayoutmanager.cxx")
 140             && !loplugin::isSamePathname(fn, SRCDIR
 141                                          "/framework/source/fwe/helper/actiontriggerhelper.cxx")
 142             && !loplugin::isSamePathname(fn, SRCDIR "/sc/source/ui/unoobj/unodoc.cxx")
 143             && !loplugin::isSamePathname(fn, SRCDIR "/sc/source/ui/unoobj/filtuno.cxx")
 144             && !loplugin::isSamePathname(fn, SRCDIR "/sc/source/ui/unoobj/funcuno.cxx")
 145             && !loplugin::isSamePathname(fn, SRCDIR "/sc/source/ui/vba/vbaapplication.cxx")
 146             && !loplugin::isSamePathname(fn, SRCDIR "/sd/source/ui/unoidl/unodoc.cxx")
 147             && !loplugin::isSamePathname(fn, SRCDIR "/sd/source/ui/unoidl/unomodule.cxx")
 148             && !loplugin::isSamePathname(fn, SRCDIR "/sd/source/ui/remotecontrol/Receiver.cxx")
 149             && !loplugin::isSamePathname(fn, SRCDIR
 150                                          "/sd/source/ui/slidesorter/controller/SlsClipboard.cxx")
 151             && !loplugin::isSamePathname(fn, SRCDIR "/sfx2/source/appl/fwkhelper.cxx")
 152             && !loplugin::isSamePathname(fn, SRCDIR "/sfx2/source/appl/appinit.cxx")
 153             && !loplugin::isSamePathname(fn, SRCDIR "/sfx2/source/appl/shutdownicon.cxx")
 154             && !loplugin::isSamePathname(fn, SRCDIR "/sfx2/source/dialog/dockwin.cxx")
 155             && !loplugin::isSamePathname(fn, SRCDIR "/sfx2/source/statbar/stbitem.cxx")
 156             && !loplugin::isSamePathname(fn, SRCDIR "/sfx2/source/toolbox/tbxitem.cxx")
 157             && !loplugin::isSamePathname(fn,
 158                                          SRCDIR "/svtools/source/java/javainteractionhandler.cxx")
 159             && !loplugin::isSamePathname(fn,
 160                                          SRCDIR "/svx/source/accessibility/ShapeTypeHandler.cxx")
 161             && !loplugin::isSamePathname(fn,
 162                                          SRCDIR "/svx/source/tbxctrls/tbunosearchcontrollers.cxx")
 163             && !loplugin::isSamePathname(fn, SRCDIR "/svx/source/form/fmscriptingenv.cxx")
 164             && !loplugin::isSamePathname(fn, SRCDIR "/svx/source/fmcomp/fmgridif.cxx")
 165             && !loplugin::isSamePathname(fn, SRCDIR "/toolkit/source/awt/vclxspinbutton.cxx")
 166             && !loplugin::isSamePathname(fn, SRCDIR "/toolkit/source/awt/vclxtoolkit.cxx")
 167             && !loplugin::isSamePathname(fn,
 168                                          SRCDIR "/toolkit/source/controls/tree/treecontrolpeer.cxx")
 169             && !loplugin::isSamePathname(fn, SRCDIR "/ucb/source/ucp/image/ucpimage.cxx")
 170             && !loplugin::hasPathnamePrefix(fn, SRCDIR "/vcl/")
 171
 172             // not sure
 173             && !loplugin::isSamePathname(fn,
 174                                          SRCDIR "/dbaccess/source/ui/browser/AsynchronousLink.cxx")
 175             && !loplugin::isSamePathname(fn, SRCDIR "/framework/source/services/autorecovery.cxx")
 176             && !loplugin::isSamePathname(fn, SRCDIR "/sfx2/source/dialog/filedlghelper.cxx")
 177             && !loplugin::isSamePathname(fn, SRCDIR "/sfx2/source/appl/appdispatchprovider.cxx")
 178             && !loplugin::isSamePathname(fn, SRCDIR "/ucb/source/ucp/tdoc/tdoc_storage.cxx")
 179             && !loplugin::isSamePathname(fn, SRCDIR "/sc/source/core/data/poolhelp.cxx")
 180
 181             // touching shared global data
 182             && !loplugin::isSamePathname(fn, SRCDIR
 183                                          "/framework/source/fwi/classes/protocolhandlercache.cxx")
 184             && !loplugin::isSamePathname(fn,
 185                                          SRCDIR "/basic/source/basmgr/basicmanagerrepository.cxx")
 186             && !loplugin::isSamePathname(fn, SRCDIR "/basic/source/classes/sb.cxx")
 187             && !loplugin::isSamePathname(fn, SRCDIR "/sc/source/ui/unoobj/docuno.cxx")
 188             && !loplugin::isSamePathname(fn, SRCDIR "/sc/source/ui/unoobj/afmtuno.cxx")
 189             && !loplugin::isSamePathname(fn, SRCDIR "/sc/source/ui/unoobj/appluno.cxx")
 190             && !loplugin::isSamePathname(fn, SRCDIR "/sc/source/ui/vba/vbaapplication.cxx")
 191             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/core/access/accdoc.cxx")
 192             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/core/access/acccontext.cxx")
 193             && !loplugin::isSamePathname(fn,
 194                                          SRCDIR "/sw/source/core/bastyp/proofreadingiterator.cxx")
 195             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/core/unocore/unoftn.cxx")
 196             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/core/unocore/unolinebreak.cxx")
 197             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/core/unocore/unoobj.cxx")
 198             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/core/unocore/unorefmk.cxx")
 199             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/core/unocore/unotbl.cxx")
 200             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/core/unocore/unocontentcontrol.cxx")
 201             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/core/unocore/unobkm.cxx")
 202             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/core/unocore/unocoll.cxx")
 203             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/core/unocore/unostyle.cxx")
 204             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/filter/xml/xmltexti.cxx")
 205             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/uibase/uno/dlelstnr.cxx")
 206             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/uibase/uno/unoatxt.cxx")
 207             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/uibase/uno/unodoc.cxx")
 208             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/uibase/uno/unomodule.cxx")
 209             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/uibase/uno/SwXFilterOptions.cxx")
 210             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/uibase/shells/translatehelper.cxx")
 211             && !loplugin::isSamePathname(fn, SRCDIR "/sw/source/ui/vba/vbaapplication.cxx")
 212             && !loplugin::isSamePathname(fn, SRCDIR "/unoxml/source/dom/documentbuilder.cxx")
 213             && !loplugin::isSamePathname(
 214                    fn, SRCDIR "/sd/source/ui/accessibility/AccessibleDrawDocumentView.cxx")
 215             && !loplugin::isSamePathname(fn, SRCDIR "/starmath/source/accessibility.cxx")
 216             && !loplugin::isSamePathname(fn,
 217                                          SRCDIR "/starmath/source/AccessibleSmElementsControl.cxx"))
 218         {
 219             report(DiagnosticsEngine::Warning, "unnecessary locking", compoundStmt->getBeginLoc())
 220                 << compoundStmt->getSourceRange();
 221         }
 222     }
 223
 224     m_TouchesThis.pop_back();
 225     m_IgnoreThis.pop_back();
 226
 227     return true;
 228 }
 229
 230 bool UnnecessaryLocking::isSolarMutexLockGuardStmt(const Stmt* stmt)
 231 {
 232     auto declStmt = dyn_cast<DeclStmt>(stmt);
 233     if (!declStmt)
 234         return false;
 235     if (!declStmt->isSingleDecl())
 236         return false;
 237     auto varDecl = dyn_cast<VarDecl>(declStmt->getSingleDecl());
 238     if (!varDecl)
 239         return false;
 240     auto tc = loplugin::TypeCheck(varDecl->getType());
 241     if (!tc.Class("SolarMutexGuard").GlobalNamespace()
 242         && !tc.Class("SolarMutexClearableGuard").GlobalNamespace()
 243         && !tc.Class("SolarMutexResettableGuard").GlobalNamespace()
 244         && !tc.Class("SolarMutexTryAndBuyGuard").GlobalNamespace())
 245         return false;
 246     return true;
 247 }
 248
 249 const CXXThisExpr* UnnecessaryLocking::isOtherMutexLockGuardStmt(const Stmt* stmt)
 250 {
 251     auto declStmt = dyn_cast<DeclStmt>(stmt);
 252     if (!declStmt)
 253         return nullptr;
 254     if (!declStmt->isSingleDecl())
 255         return nullptr;
 256     auto varDecl = dyn_cast<VarDecl>(declStmt->getSingleDecl());
 257     if (!varDecl)
 258         return nullptr;
 259     auto tc = loplugin::TypeCheck(varDecl->getType());
 260     if (!tc.Class("unique_lock").StdNamespace() && !tc.Class("scoped_lock").StdNamespace()
 261         && !tc.Class("Guard") && !tc.Class("ClearableGuard") && !tc.Class("ResettableGuard"))
 262         return nullptr;
 263     auto cxxConstructExpr = dyn_cast<CXXConstructExpr>(varDecl->getInit());
 264     if (!cxxConstructExpr || cxxConstructExpr->getNumArgs() < 1)
 265         return nullptr;
 266     auto arg0 = cxxConstructExpr->getArg(0);
 267     if (auto memberExpr = dyn_cast<MemberExpr>(arg0))
 268     {
 269         const CXXThisExpr* thisStmt
 270             = dyn_cast<CXXThisExpr>(memberExpr->getBase()->IgnoreImplicit());
 271         return thisStmt;
 272     }
 273     else if (auto memberCallExpr = dyn_cast<CXXMemberCallExpr>(arg0))
 274     {
 275         return dyn_cast_or_null<CXXThisExpr>(
 276             memberCallExpr->getImplicitObjectArgument()->IgnoreImplicit());
 277     }
 278     return nullptr;
 279 }
 280
 281 bool UnnecessaryLocking::VisitCXXThisExpr(const CXXThisExpr* cxxThisExpr)
 282 {
 283     if (ignoreLocation(cxxThisExpr))
 284         return true;
 285     // just in case
 286     if (m_TouchesThis.empty())
 287         return true;
 288     // already found something
 289     if (m_TouchesThis.back())
 290         return true;
 291     if (m_IgnoreThis.back() && m_IgnoreThis.back() == cxxThisExpr)
 292         return true;
 293     m_TouchesThis.back() = true;
 294     return true;
 295 }
 296
 297 bool UnnecessaryLocking::VisitCallExpr(const CallExpr* callExpr)
 298 {
 299     if (ignoreLocation(callExpr))
 300         return true;
 301     // just in case
 302     if (m_TouchesThis.empty())
 303         return true;
 304     // already found something
 305     if (m_TouchesThis.back())
 306         return true;
 307     const CXXMethodDecl* callee = dyn_cast_or_null<CXXMethodDecl>(callExpr->getDirectCallee());
 308     if (!callee)
 309         return true;
 310     auto dc = loplugin::DeclCheck(callee->getParent());
 311     if (dc.Class("VCLUnoHelper") || dc.Class("Application"))
 312         m_TouchesThis.back() = true;
 313     return true;
 314 }
 315
 316 /** off by default because each warning needs to be carefully inspected */
 317 loplugin::Plugin::Registration<UnnecessaryLocking> unnecessarylocking("unnecessarylocking", false);
 318 }
 319
 320 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */