new loplugin checkunusedparams

Change-Id: I8f6974e34e686fc97014de97f072b81aa73f969b

1 files changed, 346 insertions, 0 deletions

diff --git a/compilerplugins/clang/checkunusedparams.cxx b/compilerplugins/clang/checkunusedparams.cxx
new file mode 100644
index 000000000000..3fe2d08f7928
--- /dev/null
+++ b/compilerplugins/clang/checkunusedparams.cxx
@@ -0,0 +1,346 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <cassert>
+#include <string>
+#include <set>
+
+#include "plugin.hxx"
+
+/**
+Find parameters that have no name, i.e. they are unused and we're worked around the "unused parameter" warning.
+
+Most of these can be removed.
+
+TODO look for places where we are working around the warning by doing
+    (void) param1;
+ */
+namespace {
+
+class CheckUnusedParams: public RecursiveASTVisitor<CheckUnusedParams>, public loplugin::Plugin {
+public:
+    explicit CheckUnusedParams(InstantiationData const & data): Plugin(data) {}
+    void run() override;
+    bool VisitFunctionDecl(FunctionDecl const * decl);
+    bool VisitDeclRefExpr(DeclRefExpr const *);
+private:
+    std::set<FunctionDecl const *> m_addressOfSet;
+    enum class PluginPhase { FindAddressOf, Warning };
+    PluginPhase m_phase;
+};
+
+void CheckUnusedParams::run()
+{
+    StringRef fn( compiler.getSourceManager().getFileEntryForID(
+                      compiler.getSourceManager().getMainFileID())->getName() );
+    if (fn.startswith(SRCDIR "/sal/"))
+         return;
+    // Taking pointer to function
+    if (fn == SRCDIR "/l10ntools/source/xmlparse.cxx")
+         return;
+    // macro magic which declares something needed by an external library
+    if (fn == SRCDIR "/svl/source/misc/gridprinter.cxx")
+         return;
+
+    // valid test/qa code
+    if (fn.startswith(SRCDIR "/compilerplugins/clang/test/"))
+         return;
+    if (fn == SRCDIR "/cppu/qa/test_reference.cxx")
+         return;
+
+    // leave this alone for now
+    if (fn.startswith(SRCDIR "/libreofficekit/"))
+         return;
+
+    m_phase = PluginPhase::FindAddressOf;
+    TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
+    m_phase = PluginPhase::Warning;
+    TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
+}
+
+bool CheckUnusedParams::VisitDeclRefExpr(DeclRefExpr const * declRef) {
+    if (m_phase != PluginPhase::FindAddressOf)
+        return true;
+    if (ignoreLocation(declRef))
+        return true;
+    if (isInUnoIncludeFile(compiler.getSourceManager().getSpellingLoc(declRef->getLocStart())))
+        return true;
+    auto functionDecl = dyn_cast<FunctionDecl>(declRef->getDecl());
+    if (!functionDecl)
+        return true;
+    m_addressOfSet.insert(functionDecl);
+    return true;
+}
+
+
+static int noFieldsInRecord(RecordType const * recordType) {
+    return std::distance(recordType->getDecl()->field_begin(), recordType->getDecl()->field_end());
+}
+static bool startswith(const std::string& rStr, const char* pSubStr) {
+    return rStr.compare(0, strlen(pSubStr), pSubStr) == 0;
+}
+
+bool CheckUnusedParams::VisitFunctionDecl(FunctionDecl const * decl) {
+    if (m_phase != PluginPhase::Warning)
+        return true;
+    if (m_addressOfSet.find(decl) != m_addressOfSet.end())
+        return true;
+    if (ignoreLocation(decl))
+        return true;
+    if (isInUnoIncludeFile(compiler.getSourceManager().getSpellingLoc(decl->getLocation())))
+        return true;
+
+    auto cxxMethodDecl = dyn_cast<CXXMethodDecl>(decl);
+    if (cxxMethodDecl) {
+        if (cxxMethodDecl->isVirtual())
+            return true;
+        auto cxxConstructorDecl = dyn_cast<CXXConstructorDecl>(cxxMethodDecl);
+        if (cxxConstructorDecl && cxxConstructorDecl->isCopyOrMoveConstructor())
+            return true;
+    }
+    if (!decl->isThisDeclarationADefinition())
+        return true;
+    if (decl->isFunctionTemplateSpecialization())
+        return true;
+    if (decl->isDeleted())
+        return true;
+    if (decl->getTemplatedKind() != clang::FunctionDecl::TK_NonTemplate)
+        return true;
+    if (decl->isOverloadedOperator())
+        return true;
+    if (decl->isExternC())
+        return true;
+
+    //TODO, filtering out any functions relating to class templates for now:
+    CXXRecordDecl const * r = dyn_cast<CXXRecordDecl>(decl->getDeclContext());
+    if (r != nullptr
+        && (r->getTemplateSpecializationKind() != TSK_Undeclared
+            || r->isDependentContext()))
+    {
+        return true;
+    }
+
+    FunctionDecl const * canon = decl->getCanonicalDecl();
+    std::string fqn = canon->getQualifiedNameAsString(); // becuase sometimes clang returns nonsense for the filename of canon
+    if (ignoreLocation(canon))
+        return true;
+    if (isInUnoIncludeFile(compiler.getSourceManager().getSpellingLoc(canon->getLocation())))
+        return true;
+    StringRef fn = compiler.getSourceManager().getFilename(compiler.getSourceManager().getSpellingLoc(canon->getLocStart()));
+    // Some backwards compat magic.
+    // TODO Can probably be removed, but need to do some checking
+    if (fn == SRCDIR "/include/sax/fshelper.hxx")
+         return true;
+    // Platform-specific code
+    if (fn == SRCDIR "/include/svl/svdde.hxx")
+         return true;
+    if (fn == SRCDIR "/include/vcl/svmain.hxx")
+         return true;
+    // passing pointer to function
+    if (fn == SRCDIR "/include/vcl/bitmapaccess.hxx")
+         return true;
+    if (fn == SRCDIR "/vcl/inc/unx/gtk/gtkobject.hxx")
+         return true;
+    if (fn == SRCDIR "/vcl/inc/unx/gtk/gtksalframe.hxx")
+         return true;
+    if (fn == SRCDIR "/vcl/inc/unx/gtk/gtkframe.hxx")
+         return true;
+    if (fn == SRCDIR "/vcl/unx/gtk/fpicker/SalGtkFilePicker.hxx")
+         return true;
+    if (fn == SRCDIR "/extensions/source/propctrlr/propertyeditor.hxx")
+         return true;
+    if (fn == SRCDIR "/forms/source/solar/inc/navtoolbar.hxx")
+         return true;
+    if (fn == SRCDIR "/hwpfilter/source/grammar.cxx")
+         return true;
+    if (fn == SRCDIR "/hwpfilter/source/lexer.cxx")
+         return true;
+    // marked with a TODO/FIXME
+    if (fn == SRCDIR "/vcl/inc/sallayout.hxx")
+         return true;
+    if (fn == SRCDIR "/accessibility/inc/standard/vclxaccessiblelist.hxx")
+         return true;
+    // these are "extern C" but clang doesn't seem to report that accurately
+    if (fn == SRCDIR "/sax/source/fastparser/fastparser.cxx")
+         return true;
+    // these all follow the same pattern, seems a pity to break that
+    if (fn == SRCDIR "/include/vcl/graphicfilter.hxx")
+         return true;
+    // looks like work in progress
+    if (fn == SRCDIR "/vcl/source/filter/ipdf/pdfdocument.cxx")
+         return true;
+    // macro magic
+    if (fn == SRCDIR "/basctl/source/inc/basidesh.hxx")
+         return true;
+    // template magic
+    if (fn.startswith(SRCDIR "/canvas/"))
+         return true;
+    if (fn.startswith(SRCDIR "/include/canvas/"))
+         return true;
+    if (fn == SRCDIR "/include/comphelper/unwrapargs.hxx")
+         return true;
+    // this looks like vaguely useful code (ParseError) that I'm loathe to remove
+    if (fn == SRCDIR "/connectivity/source/inc/RowFunctionParser.hxx")
+         return true;
+    if (fn == SRCDIR "/include/svx/EnhancedCustomShapeFunctionParser.hxx")
+         return true;
+    // TODO marker parameter in constructor, should probably be using an enum
+    if (fn == SRCDIR "/framework/inc/uielement/uicommanddescription.hxx")
+         return true;
+    if (fn == SRCDIR "/sd/source/ui/inc/SlideTransitionPane.hxx")
+         return true;
+    if (fn == SRCDIR "/sd/source/ui/animations/CustomAnimationPane.hxx")
+         return true;
+    if (fn == SRCDIR "/sd/source/ui/table/TableDesignPane.hxx")
+         return true;
+    // debug stuff
+    if (fn == SRCDIR "/sc/source/core/data/column2.cxx")
+         return true;
+    // weird stuff
+    if (fn == SRCDIR "/scaddins/source/analysis/analysishelper.hxx")
+         return true;
+    // SFX_DECL_CHILDWINDOWCONTEXT macro stuff
+    if (fn == SRCDIR "/sd/source/ui/inc/NavigatorChildWindow.hxx")
+         return true;
+    // TODO, need to remove this from the .sdi file too
+    if (fn == SRCDIR "/sd/source/ui/inc/SlideSorterViewShell.hxx")
+         return true;
+    if (fn == SRCDIR "/sd/source/ui/inc/OutlineViewShell.hxx")
+         return true;
+    // SFX_DECL_INTERFACE macro stuff
+    if (fn == SRCDIR "/sd/source/ui/inc/ViewShellBase.hxx")
+         return true;
+    // debug stuff
+    if (fn == SRCDIR "/sd/source/filter/ppt/pptinanimations.hxx")
+         return true;
+    // takes pointer to fn
+    if (fn == SRCDIR "/include/sfx2/shell.hxx")
+         return true;
+    // TODO, need to remove this from the .sdi file too
+    if (fqn == "SfxObjectShell::StateView_Impl")
+         return true;
+    // SFX_DECL_CHILDWINDOW_WITHID macro
+    if (fn == SRCDIR "/include/sfx2/infobar.hxx")
+         return true;
+    // this looks like vaguely useful code (ParseError) that I'm loathe to remove
+    if (fn == SRCDIR "/slideshow/source/inc/slideshowexceptions.hxx")
+         return true;
+    // SFX_DECL_VIEWFACTORY macro
+    if (fn == SRCDIR "/starmath/inc/view.hxx")
+         return true;
+    // debugging
+    if (fqn == "BrowseBox::DoShowCursor" || fqn == "BrowseBox::DoHideCursor")
+         return true;
+    // if I change this one, it then overrides a superclass virtual method
+    if (fqn == "GalleryBrowser2::KeyInput")
+         return true;
+    // takes pointer to function
+    if (fqn == "cmis::AuthProvider::onedriveAuthCodeFallback" || fqn == "cmis::AuthProvider::gdriveAuthCodeFallback")
+         return true;
+    if (fqn == "ooo_mount_operation_ask_password")
+         return true;
+    // TODO tricky to remove because of default params
+    if (fqn == "xmloff::OAttribute2Property::addBooleanProperty")
+         return true;
+    // taking pointer to function
+    if (fqn == "sw::DocumentContentOperationsManager::DeleteAndJoinWithRedlineImpl"
+        || fqn == "sw::DocumentContentOperationsManager::DeleteRangeImpl"
+        || fqn == "SwTableFormula::GetFormulaBoxes"
+        || fqn == "SwFEShell::Drag"
+        || fqn == "GetASCWriter" || fqn == "GetHTMLWriter" || fqn == "GetXMLWriter"
+        || fqn == "SwWrtShell::UpdateLayoutFrame" || fqn == "SwWrtShell::DefaultDrag"
+        || fqn == "SwWrtShell::DefaultEndDrag"
+        || startswith(fqn, "SwWW8ImplReader::Read_"))
+         return true;
+    // WIN32 only
+    if (fqn == "SwFntObj::GuessLeading")
+         return true;
+    // SFX_DECL_CHILDWINDOW_WITHID macro
+    if (fqn == "SwSpellDialogChildWindow::SwSpellDialogChildWindow"
+        || fqn == "SwFieldDlgWrapper::SwFieldDlgWrapper"
+        || fqn == "SwInputChild::SwInputChild")
+         return true;
+    // SFX_DECL_VIEWFACTORY macro
+    if (fqn == "SwSrcView::SwSrcView")
+         return true;
+    // Serves to disambiguate two very similar methods
+    if (fqn == "MSWordStyles::BuildGetSlot")
+         return true;
+    // TODO there are just too many default params to make this worth fixing right now
+    if (fqn == "ScDocument::CopyMultiRangeFromClip")
+        return true;
+    // TODO looks like this needs fixing?
+    if (fqn == "ScTable::ExtendPrintArea")
+        return true;
+    // there is a FIXME in the code
+    if (fqn == "ScRangeUtil::IsAbsTabArea")
+        return true;
+    // SFX_DECL_CHILDWINDOW_WITHID
+    if (fqn == "ScInputWindowWrapper::ScInputWindowWrapper"
+        || fqn == "sc::SearchResultsDlgWrapper::SearchResultsDlgWrapper")
+        return true;
+    // ExecMethod in .sdi file
+    if (fqn == "ScChartShell::ExecuteExportAsGraphic")
+        return true;
+    // bool marker parameter
+    if (fqn == "SvxIconReplacementDialog::SvxIconReplacementDialog")
+        return true;
+
+    // ignore the LINK macros from include/tools/link.hxx
+    if (decl->getLocation().isMacroID())
+        return true;
+
+    for( auto it = decl->param_begin(); it != decl->param_end(); ++it) {
+        auto param = *it;
+        if (param->hasAttr<UnusedAttr>())
+            continue;
+        if (!param->getName().empty())
+            continue;
+        // ignore params which are enum types with only a single enumerator, these are marker/tag types
+        auto paramType = param->getType();
+        if (paramType->isEnumeralType()) {
+            auto enumType = paramType->getAs<EnumType>();
+            int cnt = std::distance(enumType->getDecl()->enumerator_begin(), enumType->getDecl()->enumerator_end());
+            if (cnt == 1)
+                continue;
+        }
+        // ignore params which are a reference to a struct which has no fields.
+        // These are either
+        //  (a) marker/tag types
+        //  (b) selective "friend" access
+        if (paramType->isReferenceType()) {
+            auto referenceType = paramType->getAs<ReferenceType>();
+            if (referenceType->getPointeeType()->isRecordType()) {
+                auto recordType = referenceType->getPointeeType()->getAs<RecordType>();
+                if (noFieldsInRecord(recordType) == 0)
+                    continue;
+            }
+        }
+        else if (paramType->isRecordType()) {
+            if (noFieldsInRecord(paramType->getAs<RecordType>()) == 0)
+                continue;
+        }
+        report( DiagnosticsEngine::Warning,
+                "unused param %0 in %1", decl->getLocation())
+                << decl->getSourceRange()
+                << param->getName()
+                << fqn;
+        if (canon != decl)
+            report( DiagnosticsEngine::Note, "declaration is here",
+                    canon->getLocation())
+                    << canon->getSourceRange();
+    }
+    return true;
+}
+
+loplugin::Plugin::Registration<CheckUnusedParams> X("checkunusedparams", false);
+
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */