new loplugin:unusedvariableplus

a particularly aggressive checker, which is why it is off by default

Change-Id: Id5a0faa50b3ecc75e01f4aedc6579c5209e585da
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/91643
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

1 files changed, 510 insertions, 0 deletions

diff --git a/compilerplugins/clang/unusedvariableplus.cxx b/compilerplugins/clang/unusedvariableplus.cxx
new file mode 100644
index 000000000000..fa0e9e3992b1
--- /dev/null
+++ b/compilerplugins/clang/unusedvariableplus.cxx
@@ -0,0 +1,510 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * Based on LLVM/Clang.
+ *
+ * This file is distributed under the University of Illinois Open Source
+ * License. See LICENSE.TXT for details.
+ *
+ */
+
+#ifndef LO_CLANG_SHARED_PLUGINS
+
+#include "plugin.hxx"
+#include <unordered_set>
+
+/*
+ * Very aggressive unused variable checker, we whitelist types that are known
+ * good when unused.
+*/
+
+namespace
+{
+static bool startswith(const std::string& rStr, const char* pSubStr)
+{
+    return rStr.compare(0, strlen(pSubStr), pSubStr) == 0;
+}
+
+class UnusedVariablePlus : public loplugin::FilteringPlugin<UnusedVariablePlus>
+{
+public:
+    explicit UnusedVariablePlus(loplugin::InstantiationData const& data)
+        : FilteringPlugin(data)
+    {
+    }
+
+    virtual bool preRun() override
+    {
+        std::string fn(handler.getMainFileName());
+        loplugin::normalizeDotDotInFilePath(fn);
+        if (loplugin::hasPathnamePrefix(fn, SRCDIR "/canvas/workben/"))
+            return false;
+        if (loplugin::isSamePathname(fn, SRCDIR "/vcl/source/uipreviewer/previewer.cxx"))
+            return false;
+        if (loplugin::hasPathnamePrefix(fn, SRCDIR "/vcl/workben/"))
+            return false;
+        if (loplugin::hasPathnamePrefix(fn, SRCDIR "/vcl/qa/"))
+            return false;
+        if (loplugin::hasPathnamePrefix(fn, SRCDIR "/vcl/backendtest/"))
+            return false;
+        if (loplugin::hasPathnamePrefix(fn, SRCDIR "/lotuswordpro/"))
+            return false;
+        if (loplugin::hasPathnamePrefix(fn, SRCDIR "/salhelper/qa/"))
+            return false;
+        if (loplugin::hasPathnamePrefix(fn, SRCDIR "/sal/qa/"))
+            return false;
+        if (loplugin::isSamePathname(fn, SRCDIR "/idl/source/prj/svidl.cxx"))
+            return false;
+        if (loplugin::isSamePathname(fn, SRCDIR "/sot/source/unoolestorage/xolesimplestorage.cxx"))
+            return false;
+        if (loplugin::isSamePathname(fn, SRCDIR "/sc/source/core/tool/interpr7.cxx"))
+            return false;
+        if (loplugin::isSamePathname(fn, SRCDIR "/sc/source/ui/vba/vbaapplication.cxx"))
+            return false;
+        if (loplugin::isSamePathname(fn, SRCDIR "/sw/source/core/doc/doccomp.cxx"))
+            return false;
+        if (loplugin::isSamePathname(fn, SRCDIR "/sw/source/core/swg/SwXMLTextBlocks.cxx"))
+            return false;
+        if (loplugin::isSamePathname(fn, SRCDIR "/sw/source/filter/ww8/wrtw8esh.cxx"))
+            return false;
+        if (loplugin::isSamePathname(fn, SRCDIR
+                                     "/shell/source/sessioninstall/SyncDbusSessionHelper.cxx"))
+            return false;
+        if (loplugin::isSamePathname(fn, SRCDIR "/svl/qa/unit/items/test_IndexedStyleSheets.cxx"))
+            return false;
+        if (loplugin::isSamePathname(fn, SRCDIR "/sd/qa/unit/export-tests-ooxml2.cxx"))
+            return false;
+        if (loplugin::isSamePathname(fn, SRCDIR "/sc/qa/unit/subsequent_export-test.cxx"))
+            return false;
+        if (loplugin::isSamePathname(fn, SRCDIR "/vcl/skia/SkiaHelper.cxx"))
+            return false;
+        if (loplugin::isSamePathname(fn, SRCDIR "/svx/source/dialog/dlgctrl.cxx"))
+            return false;
+
+        // clang has a bug here, with vars in destructing assignments
+        if (loplugin::hasPathnamePrefix(fn, SRCDIR "/binaryurp/"))
+            return false;
+        if (loplugin::isSamePathname(fn, SRCDIR "/sc/source/filter/excel/xestring.cxx"))
+            return false;
+        return true;
+    }
+
+    virtual void run() override
+    {
+        if (preRun())
+            TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
+    }
+
+    bool VisitVarDecl(const VarDecl* var)
+    {
+        if (ignoreLocation(var))
+            return true;
+        if (var->isReferenced() || var->isUsed())
+            return true;
+        if (var->isDefinedOutsideFunctionOrMethod())
+            return true;
+        if (var->isExceptionVariable()) // not interesting
+            return true;
+
+        auto type = var->getType().getCanonicalType().getUnqualifiedType();
+        auto typeName = type.getAsString();
+        if (typeName.compare(0, 7, "struct ") == 0)
+            typeName = typeName.substr(7);
+        if (typeName.compare(0, 6, "class ") == 0)
+            typeName = typeName.substr(6);
+        if (typeName.compare(0, 2, "::") == 0)
+            typeName = typeName.substr(2);
+        if (typeName.compare(0, 23, "(anonymous namespace)::") == 0)
+            typeName = typeName.substr(23);
+        static std::unordered_set<std::string> ignoreClassNamesSet{
+            "apphelper::NegativeGuard<class osl::Mutex>",
+            "avmedia::gstreamer::(anonymous namespace)::FlagGuard",
+            "BoolEnv_Impl",
+            "BoolResetter",
+            "boost::io::basic_ios_all_saver<char, struct std::char_traits<char> >",
+            "BorderLinesGuard",
+            "BroadcastRecalcOnRefMoveGuard",
+            "CacheLockGuard",
+            "cc_reset",
+            "ViewCallback",
+            "chart::ControllerLockGuard",
+            "chart::ControllerLockGuardUNO",
+            "chart::HiddenUndoContext",
+            "chart::sidebar::(anonymous namespace)::PreventUpdate",
+            "chart::TimerTriggeredControllerLock",
+            "chart::TrueGuard",
+            "ClearableClipRegion",
+            "osl::ClearableGuard<class osl::Mutex>",
+            "rptui::ColorChanger",
+            "SortRefUpdateSetter",
+            "SortRefNoUpdateSetter",
+            "com::sun::star::uno::ContextLayer",
+            "comphelper::FlagGuard",
+            "comphelper::FlagRestorationGuard",
+            "comphelper::ValueRestorationGuard<_Bool>",
+            "comphelper::(anonymous namespace)::ProfileZone",
+            "comphelper::ProfileZone",
+            "comphelper::ORelease<class osl::Mutex>",
+            "comphelper::OStreamSection",
+            "ConfigurationController::Lock",
+            "SortTypeSetter",
+            "SkiaZone",
+            "MockMetadatable",
+            "connectivity::(anonymous namespace)::ForbidQueryName",
+            "connectivity::calc::OCalcConnection::ODocHolder",
+            "connectivity::writer::OWriterConnection::ODocHolder",
+            "connectivity::jdbc::ContextClassLoaderScope",
+            "CurrShell",
+            "dbaccess::ModifyLock",
+            "dbaccess::NameChangeNotifier",
+            "dbaccess::OFilteredContainer::EnsureReset",
+            "dbaccess::OQuery::OAutoActionReset",
+            "dbaccess::OQueryContainer::OAutoActionReset",
+            "dbaccess::(anonymous namespace)::LayoutManagerLock",
+            "dbaccess::(anonymous namespace)::LockModifiable",
+            "dbaccess::(anonymous namespace)::OExecuteImpl",
+            "dbaccess::(anonymous namespace)::PreserveVisualAreaSize",
+            "dbaccess::(anonymous namespace)::ProtectFlag",
+            "dbaui::BrowserViewStatusDisplay",
+            "dbaui::SbaXDataBrowserController::FormErrorHelper",
+            "dbaui::(anonymous namespace)::SelectionGuard",
+            "dbaxml::(anonymous namespace)::FocusWindowWaitGuard",
+            "DBG_Model",
+            "DeactivateUpdateMode",
+            "desktop::Desktop",
+            "desktop::(anonymous namespace)::ConditionSetGuard",
+            "desktop::(anonymous namespace)::RefClearGuard<class "
+            "com::sun::star::uno::Reference<class com::sun::star::frame::XSynchronousDispatch> "
+            ">",
+            "DetachCurrentThread",
+            "DialogReleaseGuard",
+            "DisableCallbackAction",
+            "DisableCallbacks",
+            "DisableGetPivotData",
+            "DispatchMutexLock_Impl",
+            "DocTemplLocker_Impl",
+            "DocumentSettingsGuard",
+            "DocxTableExportContext",
+            "dp_misc::AbortChannel::Chain",
+            "dp_misc::ProgressLevel",
+            "E3DModifySceneSnapRectUpdater",
+            "E3dObjFactory",
+            "ErrorHdlResetter",
+            "EscherExAtom",
+            "EscherExContainer",
+            "ExportDataSaveRestore",
+            "ExtensionRemoveGuard",
+            "frm::(anonymous namespace)::FieldChangeNotifier",
+            "frm::(anonymous namespace)::DocumentModifyGuard",
+            "FieldDeletionModify",
+            "FieldDeletionListener",
+            "FileHandle_Impl::Guard",
+            "FlowFrameJoinLockGuard",
+            "FmXFormShell::SuspendPropertyTracking",
+            "FocusWindowWaitCursor",
+            "formula::(anonymous namespace)::OpCodeList",
+            "formula::(anonymous namespace)::FormulaCompilerRecursionGuard",
+            "FontCacheGuard",
+            "FontLockGuard",
+            "FormatLevel",
+            "FormulaGrammarSwitch",
+            "framework::DocumentUndoGuard",
+            "framework::ShareGuard",
+            "framework::TransactionGuard",
+            "framework::(anonymous namespace)::QuickstartSuppressor",
+            "GalApp",
+            "GalleryProgress",
+            "GlibThreadDefaultMainContextScope",
+            "Guard",
+            "HandleResetAttrAtTextNode",
+            "HandleSetAttrAtTextNode",
+            "HelpParser",
+            "HtmlExport",
+            "HTMLSaveData",
+            "IMapCompat",
+            "jni_uno::JLocalAutoRef",
+            "LoadMediumGuard",
+            "LockGuard",
+            "MacroInterpretIncrementer",
+            "MailMergeExecuteFinalizer",
+            "ModifyBlocker_Impl",
+            "MutexRelease",
+            "MutexType",
+            "NewTextListsHelper",
+            "OAutoRegistration",
+            "rptui::GeometryHandler::OBlocker",
+            "rptui::OXReportControllerObserver::OEnvLock",
+            "oglcanvas::TransformationPreserver",
+            "io_acceptor::(anonymous namespace)::BeingInAccept",
+            "desktop::LibLibreOffice_Impl",
+            "ToolbarUnoDispatcher",
+            "ooo::vba::excel::(anonymous namespace)::PasteCellsWarningReseter",
+            "oox::drawingml::(anonymous namespace)::ActionLockGuard",
+            "oox::dump::IndentGuard",
+            "oox::dump::ItemGuard",
+            "oox::dump::MultiItemsGuard",
+            "oox::dump::TableGuard",
+            "OpenCLInitialZone",
+            "OpenCLZone",
+            "OpenGLVCLContextZone",
+            "OpenGLZone",
+            "osl::MutexGuard",
+            "rptui::OXUndoEnvironment::OUndoMode",
+            "rptui::OXUndoEnvironment::OUndoEnvLock",
+            "PaMIntoCursorShellRing",
+            "ParserCleanup",
+            "BorderTest",
+            "pcr::ComposedUIAutoFireGuard",
+            "writerperfect::(anonymous namespace)::PositionHolder",
+            "pq_sdbc_driver::DisposeGuard",
+            "PropertyChangeNotifier",
+            "ProtectFormulaGroupContext",
+            "PreventUpdate",
+            "pyuno::PyThreadAttach",
+            "pyuno::PyThreadDetach",
+            "pyuno_loader::(anonymous namespace)::PythonInit",
+            "RecursionCounter",
+            "RefGuard",
+            "icu_65::RegexMatcher",
+            "RestoreMapMode",
+            "Runner",
+            "pyuno::Runtime",
+            "salhelper::ConditionModifier",
+            "salhelper::ConditionWaiter",
+            "SaveRunState",
+            "SbiExpression",
+            "sc::AutoCalcSwitch",
+            "sc::DelayFormulaGroupingSwitch",
+            "sc::IdleSwitch",
+            "sc::UndoSwitch",
+            "ScBulkBroadcast",
+            "ScChartLockGuard",
+            "ScCompiler",
+            "ScDocument::NumFmtMergeHandler",
+            "ScDocShellModificator",
+            "ScDocShell::PrepareSaveGuard",
+            "ScExternalRefManager::ApiGuard",
+            "ScFormulaGroupCycleCheckGuard",
+            "ScFormulaGroupDependencyComputeGuard",
+            "SchedulerGuard",
+            "ScMutationDisable",
+            "ScNoteCaptionCreator",
+            "ScValidationRegisteredDlg",
+            "ScopedAntialiasing",
+            "ScRefreshTimerProtector",
+            "ScWaitCursorOff",
+            "ScXMLImport::MutexGuard",
+            "SdIOCompat",
+            "sd::slidesorter::controller::FocusManager::FocusHider",
+            "sd::slidesorter::controller::SlideSorterController::ModelChangeLock",
+            "sd::slidesorter::controller::PageSelector::BroadcastLock",
+            "sd::slidesorter::view::SlideSorterView::DrawLock",
+            "sd::slidesorter::controller::PageSelector::UpdateLock",
+            "sd::ViewShellManager::Implementation::UpdateLock",
+            "sd::(anonymous namespace)::LockUI",
+            "sd::ToolBarManager::UpdateLock",
+            "sd::ViewShellManager::UpdateLock",
+            "sd::OutlineViewPageChangesGuard",
+            "sd::framework::ConfigurationController::Lock",
+            "sd::slidesorter::controller::VisibleAreaManager::TemporaryDisabler",
+            "sd::slidesorter::controller::SelectionObserver::Context",
+            "sd::ToolBarManager::Implementation::UpdateLockImplementation",
+            "sd::OutlineViewModelChangeGuard",
+            "sd::slidesorter::controller::(anonymous "
+            "namespace)::TemporarySlideTrackingDeactivator",
+            "sd::ModifyGuard",
+            "sd::OutlineViewModelChangeGuard",
+            "setFastDocumentHandlerGuard",
+            "SfxErrorContext",
+            "SfxObjectShellLock",
+            "SfxProgress",
+            "SfxSaveGuard",
+            "SfxStack",
+            "ShellMoveCursor",
+            "SkAutoCanvasRestore",
+            "SolarMutexGuard",
+            "SolarMutexReleaser",
+            "StackHack",
+            "std::scoped_lock<class std::mutex>",
+            "std::unique_ptr<class com::sun::star::uno::ContextLayer, struct "
+            "std::default_delete<class com::sun::star::uno::ContextLayer> >",
+            "std::unique_ptr<class weld::WaitObject, struct std::default_delete<class "
+            "weld::WaitObject> >",
+            "std::unique_ptr<class ClearableClipRegion, struct o3tl::default_delete<class "
+            "ClearableClipRegion> >",
+            "std::unique_ptr<class SwDocShell::LockAllViewsGuard, struct "
+            "std::default_delete<class "
+            "SwDocShell::LockAllViewsGuard> >",
+            "std::unique_ptr<class SwSaveFootnoteHeight, struct std::default_delete<class "
+            "SwSaveFootnoteHeight> >",
+            "std::unique_ptr<class SwModelTestBase::Resetter, struct std::default_delete<class "
+            "SwModelTestBase::Resetter> >",
+            "StreamExceptionsEnabler",
+            "SvAddressParser_Impl",
+            "svl::undo::impl::LockGuard",
+            "svt::table::(anonymous namespace)::SuppressCursor",
+            "svx::(anonymous namespace)::FontSwitch",
+            "SvXMLElementExport",
+            "svxform::(anonymous namespace)::QuitGuard",
+            "sw::DrawUndoGuard",
+            "sw::UndoGuard",
+            "sw::GroupUndoGuard",
+            "sw::(anonymous namespace)::CursorGuard",
+            "SwActContext",
+            "SwAutoFormat",
+            "SwCallLink",
+            "SwContentNotify",
+            "SwCursorSaveState",
+            "SwCSS1OutMode",
+            "SwDataChanged",
+            "SwDigitModeModifier",
+            "SwDrawViewSave",
+            "SwDropSave",
+            "SwEnhancedPDFExportHelper",
+            "SwEnterLeave",
+            "SwFieldSlot",
+            "SwFilterOptions",
+            "SwFntAccess",
+            "SwFontSave",
+            "SwFootnoteSave",
+            "SwFrameDeleteGuard",
+            "SwModelTestBase::Resetter",
+            "std::unique_ptr<class ScTokenArray, struct std::default_delete<class "
+            "ScTokenArray> >", // ScCompiler::CompileString has nasty semantics
+            "Resetter",
+            "SwFrameSwapper",
+            "SwFlyNotify",
+            "SwForbidFollowFormat",
+            "SwHandleAnchorNodeChg",
+            "SwHookOut",
+            "SwImplShellAction",
+            "SwKeepConversionDirectionStateContext",
+            "SwLayIdle",
+            "SwLayNotify",
+            "SwLayoutModeModifier",
+            "SwMvContext",
+            "SwNotifyAccAboutInvalidTextSelections",
+            "SwObjPositioningInProgress",
+            "SwParaSelection",
+            "SwPauseThreadStarting",
+            "SwPosNotify",
+            "SwRedlineItr", // ???
+            "SwRegHistory",
+            "SwSaveFootnoteHeight",
+            "SwSaveSetLRUOfst",
+            "SwStyleBase_Impl::ItemSetOverrider",
+            "SwSwapIfNotSwapped",
+            "SwSwapIfSwapped",
+            "SwTableNumFormatMerge",
+            "SwTaggedPDFHelper",
+            "SwTestFormat",
+            "SwTextCursorSave",
+            "SwTextSlot",
+            "SwTrnsfrActionAndUndo",
+            "SwWait",
+            "SwXDispatchProviderInterceptor::DispatchMutexLock_Impl",
+            "TableWait",
+            "TargetStateControl_Impl",
+            "TempErrorHandler",
+            "TemporaryCellGroupMaker",
+            "TemporaryRedlineUpdater",
+            "TextFrameLockGuard",
+            "TimerContext",
+            "TimerTriggeredControllerLock",
+            "ToggleSaveToModule",
+            "toolkit::(anonymous namespace)::ResetFlagOnExit",
+            "TravelSuspension",
+            "TreeUpdateSwitch",
+            "rptui::UndoContext",
+            "rptui::UndoSuppressor",
+            "UndoRedoRedlineGuard",
+            "UnoActionRemoveContext",
+            "UnoActionContext",
+            "UpdateFontsGuard",
+            "utl::CloseableComponent",
+            "utl::DisposableComponent",
+            "ValueCounter_Impl",
+            "VclListenerLock",
+            "vclcanvas::tools::OutDevStateKeeper",
+            "vcl::PaintBufferGuard",
+            "vcl::RoadmapWizardTravelSuspension",
+            "vcl::ScopedAntialiasing",
+            "vcl::WizardTravelSuspension",
+            "VerbExecutionControllerGuard",
+            "VersionCompat",
+            "SlideShowImpl::WaitSymbolLock",
+            "webdav_ucp::NeonHeadRequest",
+            "webdav_ucp::NeonPropFindRequest",
+            "webdav_ucp::NeonUri",
+            "WaitObject",
+            "weld::WaitObject",
+            "writerfilter::ooxml::(anonymous namespace)::StatusIndicatorGuard",
+            "WriterSpecificAutoFormatBlock",
+            "xmloff::OOfficeFormsExport",
+            "xmlscript::(anonymous namespace)::MGuard",
+            "XMLTextCharStyleNamesElementExport",
+        };
+        if (ignoreClassNamesSet.find(typeName) != ignoreClassNamesSet.end())
+            return true;
+        if (startswith(typeName, "comphelper::ScopeGuard<"))
+            return true;
+        if (startswith(typeName, "comphelper::ValueRestorationGuard<"))
+            return true;
+        if (startswith(typeName, "osl::Guard<"))
+            return true;
+        if (startswith(typeName, "dbaui::OMultiInstanceAutoRegistration<"))
+            return true;
+        if (startswith(typeName, "pcr::OAutoRegistration<"))
+            return true;
+
+        if (var->getIdentifier())
+        {
+            auto name = var->getName();
+            if (name == "aBroadcastGuard" || name == "aDeleteRef" || name == "aGuard"
+                || name == "aGuard2" || name == "aHoldSelf" || name == "aKeepDoc"
+                || name == "aAutoRegistration" || name == "aLoadContentIfExists"
+                || name == "aOwnRef" || name == "createImpl" || name == "flyHolder"
+                || name == "guard" || name == "ensureDelete" || name == "s_xTerminateListener"
+                || name == "pThis" || name == "pOldViewShell" || name == "self"
+                || name == "xDocStor" || name == "xDeleteUponLeaving" || name == "xDeleteRef"
+                || name == "xHoldAlive" || name == "xHolder" || name == "xHoldRefForMethodAlive"
+                || name == "xLock" || name == "xMutexGuard" || name == "xKeepAlive"
+                || name == "xKeepContentHolderAlive" || name == "xKeepDocAlive"
+                || name == "xKeepMeAlive" || name == "xKeepProviderAlive"
+                || name == "xOperationHold" || name == "xPreventDelete" || name == "xSelf"
+                || name == "xSelfHold" || name == "xTempHold" || name == "xDisposeAfterNewOne"
+                || name == "xThis" || name == "xThisPackage" || name == "xTriggerInit"
+                || name == "xLifeCycle" || name == "xAnotherLifeCycle")
+                return true;
+        }
+
+        if (isa<ParmVarDecl>(var))
+            return true;
+
+        if (typeName.find("Reference") != std::string::npos && var->getInit())
+        {
+            if (auto cxxConstructExpr
+                = dyn_cast<CXXConstructExpr>(var->getInit()->IgnoreImplicit()))
+                if (cxxConstructExpr->getNumArgs() == 2)
+                    if (auto param1 = dyn_cast<DeclRefExpr>(cxxConstructExpr->getArg(1)))
+                        if (auto enumDecl = dyn_cast<EnumConstantDecl>(param1->getDecl()))
+                            if (enumDecl->getName() == "UNO_QUERY_THROW"
+                                || enumDecl->getName() == "UNO_SET_THROW")
+                                return true;
+        }
+
+        report(DiagnosticsEngine::Warning, "unused variable %0 of type %1", var->getLocation())
+            << var->getDeclName() << typeName;
+
+        return true;
+    }
+};
+
+loplugin::Plugin::Registration<UnusedVariablePlus> unusedvariableplus("unusedvariableplus", false);
+
+} // namespace
+
+#endif // LO_CLANG_SHARED_PLUGINS
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */