compilerplugins/clang/checkunusedparams.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 <set>
  13 #include <iostream>
  14
  15 #include "plugin.hxx"
  16
  17 /**
  18 Find parameters that have no name, i.e. they are unused and we're worked around the "unused parameter" warning.
  19
  20 Most of these can be removed.
  21
  22 TODO look for places where we are working around the warning by doing
  23     (void) param1;
  24  */
  25 namespace {
  26
  27 class CheckUnusedParams: public loplugin::FilteringPlugin<CheckUnusedParams> {
  28 public:
  29     explicit CheckUnusedParams(loplugin::InstantiationData const & data):
  30         FilteringPlugin(data) {}
  31     void run() override;
  32     bool VisitFunctionDecl(FunctionDecl const *);
  33     bool VisitUnaryOperator(UnaryOperator const *);
  34     bool VisitInitListExpr(InitListExpr const *);
  35     bool VisitCallExpr(CallExpr const *);
  36     bool VisitBinaryOperator(BinaryOperator const *);
  37     bool VisitCXXConstructExpr(CXXConstructExpr const *);
  38 private:
  39     void checkForFunctionDecl(Expr const *, bool bCheckOnly = false);
  40     std::set<FunctionDecl const *> m_addressOfSet;
  41     enum class PluginPhase { FindAddressOf, Warning };
  42     PluginPhase m_phase;
  43 };
  44
  45 void CheckUnusedParams::run()
  46 {
  47     StringRef fn(handler.getMainFileName());
  48     if (loplugin::hasPathnamePrefix(fn, SRCDIR "/sal/"))
  49          return;
  50     // Taking pointer to function
  51     if (loplugin::isSamePathname(fn, SRCDIR "/l10ntools/source/xmlparse.cxx"))
  52          return;
  53     // macro magic which declares something needed by an external library
  54     if (loplugin::isSamePathname(fn, SRCDIR "/svl/source/misc/gridprinter.cxx"))
  55          return;
  56
  57     // valid test/qa code
  58     if (loplugin::hasPathnamePrefix(fn, SRCDIR "/compilerplugins/clang/test/"))
  59          return;
  60     if (loplugin::isSamePathname(fn, SRCDIR "/cppu/qa/test_reference.cxx"))
  61          return;
  62
  63     // leave this alone for now
  64     if (loplugin::hasPathnamePrefix(fn, SRCDIR "/libreofficekit/"))
  65          return;
  66     // this has a certain pattern to its code which appears to include lots of unused params
  67     if (loplugin::hasPathnamePrefix(fn, SRCDIR "/xmloff/"))
  68          return;
  69     // I believe someone is busy working on this chunk of code
  70     if (loplugin::isSamePathname(fn, SRCDIR "/sc/source/ui/docshell/dataprovider.cxx"))
  71          return;
  72     // I think erack is working on stuff here
  73     if (loplugin::isSamePathname(fn, SRCDIR "/sc/source/filter/excel/xiformula.cxx"))
  74          return;
  75     // lots of callbacks here
  76     if (loplugin::isSamePathname(fn, SRCDIR "/sc/source/filter/lotus/op.cxx"))
  77          return;
  78     // template magic
  79     if (loplugin::isSamePathname(fn, SRCDIR "/sc/source/filter/html/htmlpars.cxx"))
  80          return;
  81
  82     m_phase = PluginPhase::FindAddressOf;
  83     TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
  84     m_phase = PluginPhase::Warning;
  85     TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
  86 }
  87
  88 bool CheckUnusedParams::VisitUnaryOperator(UnaryOperator const * op) {
  89     if (op->getOpcode() != UO_AddrOf) {
  90         return true;
  91     }
  92     if (m_phase != PluginPhase::FindAddressOf)
  93         return true;
  94     checkForFunctionDecl(op->getSubExpr());
  95     return true;
  96 }
  97
  98 bool CheckUnusedParams::VisitBinaryOperator(BinaryOperator const * binaryOperator) {
  99     if (binaryOperator->getOpcode() != BO_Assign) {
 100         return true;
 101     }
 102     if (m_phase != PluginPhase::FindAddressOf)
 103         return true;
 104     checkForFunctionDecl(binaryOperator->getRHS());
 105     return true;
 106 }
 107
 108 bool CheckUnusedParams::VisitCallExpr(CallExpr const * callExpr) {
 109     if (m_phase != PluginPhase::FindAddressOf)
 110         return true;
 111     for (auto arg : callExpr->arguments())
 112         checkForFunctionDecl(arg);
 113     return true;
 114 }
 115
 116 bool CheckUnusedParams::VisitCXXConstructExpr(CXXConstructExpr const * constructExpr) {
 117     if (m_phase != PluginPhase::FindAddressOf)
 118         return true;
 119     for (auto arg : constructExpr->arguments())
 120         checkForFunctionDecl(arg);
 121     return true;
 122 }
 123
 124 bool CheckUnusedParams::VisitInitListExpr(InitListExpr const * initListExpr) {
 125     if (m_phase != PluginPhase::FindAddressOf)
 126         return true;
 127     for (auto subStmt : *initListExpr)
 128         checkForFunctionDecl(dyn_cast<Expr>(subStmt));
 129     return true;
 130 }
 131
 132 void CheckUnusedParams::checkForFunctionDecl(Expr const * expr, bool bCheckOnly) {
 133     auto e1 = expr->IgnoreParenCasts();
 134     auto declRef = dyn_cast<DeclRefExpr>(e1);
 135     if (!declRef)
 136         return;
 137     auto functionDecl = dyn_cast<FunctionDecl>(declRef->getDecl());
 138     if (!functionDecl)
 139         return;
 140     if (bCheckOnly)
 141         getParentStmt(expr)->dump();
 142     else
 143         m_addressOfSet.insert(functionDecl->getCanonicalDecl());
 144 }
 145
 146 static int noFieldsInRecord(RecordType const * recordType) {
 147     auto recordDecl = recordType->getDecl();
 148     // if it's complicated, lets just assume it has fields
 149     if (isa<ClassTemplateSpecializationDecl>(recordDecl))
 150         return 1;
 151     return std::distance(recordDecl->field_begin(), recordDecl->field_end());
 152 }
 153 static bool startswith(const std::string& rStr, const char* pSubStr) {
 154     return rStr.compare(0, strlen(pSubStr), pSubStr) == 0;
 155 }
 156 static bool endswith(const std::string& rStr, const char* pSubStr) {
 157     auto len = strlen(pSubStr);
 158     if (len > rStr.size())
 159         return false;
 160     return rStr.compare(rStr.size() - len, rStr.size(), pSubStr) == 0;
 161 }
 162
 163 bool CheckUnusedParams::VisitFunctionDecl(FunctionDecl const * decl) {
 164     if (m_phase != PluginPhase::Warning)
 165         return true;
 166     if (m_addressOfSet.find(decl->getCanonicalDecl()) != m_addressOfSet.end())
 167         return true;
 168     if (ignoreLocation(decl))
 169         return true;
 170     if (isInUnoIncludeFile(compiler.getSourceManager().getSpellingLoc(decl->getLocation())))
 171         return true;
 172
 173     auto cxxMethodDecl = dyn_cast<CXXMethodDecl>(decl);
 174     if (cxxMethodDecl) {
 175         if (cxxMethodDecl->isVirtual())
 176             return true;
 177         auto cxxConstructorDecl = dyn_cast<CXXConstructorDecl>(cxxMethodDecl);
 178         if (cxxConstructorDecl && cxxConstructorDecl->isCopyOrMoveConstructor())
 179             return true;
 180     }
 181     if (!decl->isThisDeclarationADefinition())
 182         return true;
 183     if (decl->isFunctionTemplateSpecialization())
 184         return true;
 185     if (decl->isDeleted())
 186         return true;
 187     if (decl->getTemplatedKind() != clang::FunctionDecl::TK_NonTemplate)
 188         return true;
 189     if (decl->isOverloadedOperator())
 190         return true;
 191     if (decl->isExternC())
 192         return true;
 193
 194     //TODO, filtering out any functions relating to class templates for now:
 195     CXXRecordDecl const * r = dyn_cast<CXXRecordDecl>(decl->getDeclContext());
 196     if (r != nullptr
 197         && (r->getTemplateSpecializationKind() != TSK_Undeclared
 198             || r->isDependentContext()))
 199     {
 200         return true;
 201     }
 202     FunctionDecl const * canon = decl->getCanonicalDecl();
 203     std::string fqn = canon->getQualifiedNameAsString(); // because sometimes clang returns nonsense for the filename of canon
 204     if (ignoreLocation(canon))
 205         return true;
 206     if (isInUnoIncludeFile(compiler.getSourceManager().getSpellingLoc(canon->getLocation())))
 207         return true;
 208     StringRef fn = getFilenameOfLocation(compiler.getSourceManager().getSpellingLoc(compat::getBeginLoc(canon)));
 209     // Some backwards compat magic.
 210     // TODO Can probably be removed, but need to do some checking
 211     if (loplugin::isSamePathname(fn, SRCDIR "/include/sax/fshelper.hxx"))
 212          return true;
 213     // Platform-specific code
 214     if (loplugin::isSamePathname(fn, SRCDIR "/include/svl/svdde.hxx"))
 215          return true;
 216     if (loplugin::isSamePathname(fn, SRCDIR "/include/vcl/svmain.hxx"))
 217          return true;
 218     // passing pointer to function
 219     if (loplugin::isSamePathname(fn, SRCDIR "/include/vcl/BitmapReadAccess.hxx"))
 220          return true;
 221     if (loplugin::isSamePathname(fn, SRCDIR "/vcl/inc/unx/gtk/gtkobject.hxx"))
 222          return true;
 223     if (loplugin::isSamePathname(fn, SRCDIR "/vcl/inc/unx/gtk/gtksalframe.hxx"))
 224          return true;
 225     if (loplugin::isSamePathname(fn, SRCDIR "/vcl/inc/unx/gtk/gtkframe.hxx"))
 226          return true;
 227     if (loplugin::isSamePathname(fn, SRCDIR "/vcl/unx/gtk/fpicker/SalGtkFilePicker.hxx"))
 228          return true;
 229     if (loplugin::isSamePathname(fn, SRCDIR "/extensions/source/propctrlr/propertyeditor.hxx"))
 230          return true;
 231     if (loplugin::isSamePathname(fn, SRCDIR "/forms/source/solar/inc/navtoolbar.hxx"))
 232          return true;
 233     if (loplugin::isSamePathname(fn, SRCDIR "/hwpfilter/source/grammar.cxx"))
 234          return true;
 235     if (loplugin::isSamePathname(fn, SRCDIR "/hwpfilter/source/lexer.cxx"))
 236          return true;
 237     // marked with a TODO/FIXME
 238     if (loplugin::isSamePathname(fn, SRCDIR "/vcl/inc/sallayout.hxx"))
 239          return true;
 240     if (loplugin::isSamePathname(fn, SRCDIR "/accessibility/inc/standard/vclxaccessiblelist.hxx"))
 241          return true;
 242     // these are "extern C" but clang doesn't seem to report that accurately
 243     if (loplugin::isSamePathname(fn, SRCDIR "/sax/source/fastparser/fastparser.cxx"))
 244          return true;
 245     // these all follow the same pattern, seems a pity to break that
 246     if (loplugin::isSamePathname(fn, SRCDIR "/include/vcl/graphicfilter.hxx"))
 247          return true;
 248     // looks like work in progress
 249     if (loplugin::isSamePathname(fn, SRCDIR "/vcl/source/filter/ipdf/pdfdocument.cxx"))
 250          return true;
 251     // macro magic
 252     if (loplugin::isSamePathname(fn, SRCDIR "/basctl/source/inc/basidesh.hxx"))
 253          return true;
 254     // template magic
 255     if (loplugin::hasPathnamePrefix(fn, SRCDIR "/canvas/"))
 256          return true;
 257     if (loplugin::hasPathnamePrefix(fn, SRCDIR "/include/canvas/"))
 258          return true;
 259     if (loplugin::isSamePathname(fn, SRCDIR "/include/comphelper/unwrapargs.hxx"))
 260          return true;
 261     // this looks like vaguely useful code (ParseError) that I'm loathe to remove
 262     if (loplugin::isSamePathname(fn, SRCDIR "/connectivity/source/inc/RowFunctionParser.hxx"))
 263          return true;
 264     if (loplugin::isSamePathname(fn, SRCDIR "/include/svx/EnhancedCustomShapeFunctionParser.hxx"))
 265          return true;
 266     // TODO marker parameter in constructor, should probably be using an enum
 267     if (loplugin::isSamePathname(fn, SRCDIR "/framework/inc/uielement/uicommanddescription.hxx"))
 268          return true;
 269     if (loplugin::isSamePathname(fn, SRCDIR "/sd/source/ui/inc/SlideTransitionPane.hxx"))
 270          return true;
 271     if (loplugin::isSamePathname(fn, SRCDIR "/sd/source/ui/animations/CustomAnimationPane.hxx"))
 272          return true;
 273     if (loplugin::isSamePathname(fn, SRCDIR "/sd/source/ui/table/TableDesignPane.hxx"))
 274          return true;
 275     // debug stuff
 276     if (loplugin::isSamePathname(fn, SRCDIR "/sc/source/core/data/column2.cxx"))
 277          return true;
 278     // weird stuff
 279     if (loplugin::isSamePathname(fn, SRCDIR "/scaddins/source/analysis/analysishelper.hxx"))
 280          return true;
 281     // SFX_DECL_CHILDWINDOWCONTEXT macro stuff
 282     if (loplugin::isSamePathname(fn, SRCDIR "/sd/source/ui/inc/NavigatorChildWindow.hxx"))
 283          return true;
 284     // TODO, need to remove this from the .sdi file too
 285     if (loplugin::isSamePathname(fn, SRCDIR "/sd/source/ui/inc/SlideSorterViewShell.hxx"))
 286          return true;
 287     if (loplugin::isSamePathname(fn, SRCDIR "/sd/source/ui/inc/OutlineViewShell.hxx"))
 288          return true;
 289     // SFX_DECL_INTERFACE macro stuff
 290     if (loplugin::isSamePathname(fn, SRCDIR "/sd/source/ui/inc/ViewShellBase.hxx"))
 291          return true;
 292     // debug stuff
 293     if (loplugin::isSamePathname(fn, SRCDIR "/sd/source/filter/ppt/pptinanimations.hxx"))
 294          return true;
 295     // takes pointer to fn
 296     if (loplugin::isSamePathname(fn, SRCDIR "/include/sfx2/shell.hxx"))
 297          return true;
 298     // TODO, need to remove this from the .sdi file too
 299     if (fqn == "SfxObjectShell::StateView_Impl")
 300          return true;
 301     // SFX_DECL_CHILDWINDOW_WITHID macro
 302     if (loplugin::isSamePathname(fn, SRCDIR "/include/sfx2/infobar.hxx"))
 303          return true;
 304     // this looks like vaguely useful code (ParseError) that I'm loathe to remove
 305     if (loplugin::isSamePathname(fn, SRCDIR "/slideshow/source/inc/slideshowexceptions.hxx"))
 306          return true;
 307     // SFX_DECL_VIEWFACTORY macro
 308     if (loplugin::isSamePathname(fn, SRCDIR "/starmath/inc/view.hxx"))
 309          return true;
 310     // debugging
 311     if (fqn == "BrowseBox::DoShowCursor" || fqn == "BrowseBox::DoHideCursor")
 312          return true;
 313     // if I change this one, it then overrides a superclass virtual method
 314     if (fqn == "GalleryBrowser2::KeyInput")
 315          return true;
 316     // takes pointer to function
 317     if (fqn == "cmis::AuthProvider::onedriveAuthCodeFallback" || fqn == "cmis::AuthProvider::gdriveAuthCodeFallback")
 318          return true;
 319     if (fqn == "ooo_mount_operation_ask_password")
 320          return true;
 321     // TODO tricky to remove because of default params
 322     if (fqn == "xmloff::OAttribute2Property::addBooleanProperty")
 323          return true;
 324     // taking pointer to function
 325     if (fqn == "sw::DocumentContentOperationsManager::DeleteAndJoinWithRedlineImpl"
 326         || fqn == "sw::DocumentContentOperationsManager::DeleteRangeImpl"
 327         || fqn == "SwTableFormula::GetFormulaBoxes"
 328         || fqn == "SwFEShell::Drag"
 329         || fqn == "GetASCWriter" || fqn == "GetHTMLWriter" || fqn == "GetXMLWriter"
 330         || fqn == "SwWrtShell::UpdateLayoutFrame" || fqn == "SwWrtShell::DefaultDrag"
 331         || fqn == "SwWrtShell::DefaultEndDrag"
 332         || startswith(fqn, "SwWW8ImplReader::Read_"))
 333          return true;
 334     // WIN32 only
 335     if (fqn == "SwFntObj::GuessLeading")
 336          return true;
 337     // SFX_DECL_CHILDWINDOW_WITHID macro
 338     if (fqn == "SwSpellDialogChildWindow::SwSpellDialogChildWindow"
 339         || fqn == "SwFieldDlgWrapper::SwFieldDlgWrapper"
 340         || fqn == "SwInputChild::SwInputChild")
 341          return true;
 342     // SFX_DECL_VIEWFACTORY macro
 343     if (fqn == "SwSrcView::SwSrcView")
 344          return true;
 345     // Serves to disambiguate two very similar methods
 346     if (fqn == "MSWordStyles::BuildGetSlot")
 347          return true;
 348     // TODO there are just too many default params to make this worth fixing right now
 349     if (fqn == "ScDocument::CopyMultiRangeFromClip")
 350         return true;
 351     // TODO looks like this needs fixing?
 352     if (fqn == "ScTable::ExtendPrintArea")
 353         return true;
 354     // there is a FIXME in the code
 355     if (fqn == "ScRangeUtil::IsAbsTabArea")
 356         return true;
 357     // SFX_DECL_CHILDWINDOW_WITHID
 358     if (fqn == "ScInputWindowWrapper::ScInputWindowWrapper"
 359         || fqn == "sc::SearchResultsDlgWrapper::SearchResultsDlgWrapper")
 360         return true;
 361     // ExecMethod in .sdi file
 362     if (fqn == "ScChartShell::ExecuteExportAsGraphic")
 363         return true;
 364     // bool marker parameter
 365     if (fqn == "SvxIconReplacementDialog::SvxIconReplacementDialog")
 366         return true;
 367     // used as pointer to fn
 368     if (endswith(fqn, "_createInstance"))
 369         return true;
 370     // callback
 371     if (startswith(fqn, "SbRtl_"))
 372         return true;
 373     // takes pointer to fn
 374     if (fqn == "migration::BasicMigration_create" || fqn == "migration::WordbookMigration_create"
 375         || fqn == "comp_CBlankNode::_create" || fqn == "comp_CURI::_create"
 376         || fqn == "comp_CLiteral::_create" || fqn == "CDocumentBuilder::_getInstance"
 377         || fqn == "DOM::CDocumentBuilder::_getInstance"
 378         || fqn == "xml_security::serial_number_adapter::create"
 379         || fqn == "desktop::splash::create" || fqn == "ScannerManager_CreateInstance"
 380         || fqn == "formula::FormulaOpCodeMapperObj::create"
 381         || fqn == "(anonymous namespace)::createInstance"
 382         || fqn == "x_error_handler"
 383         || fqn == "warning_func"
 384         || fqn == "error_func"
 385         || fqn == "ScaDateAddIn_CreateInstance"
 386         || fqn == "ScaPricingAddIn_CreateInstance"
 387         || fqn == "(anonymous namespace)::PDFSigningPKCS7PasswordCallback"
 388         || fqn == "ContextMenuEventLink"
 389         || fqn == "DelayedCloseEventLink"
 390         || fqn == "GDIMetaFile::ImplColMonoFnc"
 391         || fqn == "vcl::getGlyph0"
 392         || fqn == "vcl::getGlyph6"
 393         || fqn == "vcl::getGlyph12"
 394         || fqn == "setPasswordCallback"
 395         || fqn == "VCLExceptionSignal_impl"
 396         || fqn == "getFontTable"
 397         || fqn == "textconversiondlgs::ChineseTranslation_UnoDialog::create"
 398         || fqn == "pcr::DefaultHelpProvider::Create"
 399         || fqn == "pcr::DefaultFormComponentInspectorModel::Create"
 400         || fqn == "pcr::ObjectInspectorModel::Create"
 401         || fqn == "GraphicExportFilter::GraphicExportFilter"
 402         || fqn == "CertificateContainer::CertificateContainer"
 403         || startswith(fqn, "ParseCSS1_")
 404         )
 405          return true;
 406     // TODO
 407     if (fqn == "FontSubsetInfo::CreateFontSubsetFromType1")
 408          return true;
 409     // used in template magic
 410     if (fqn == "MtfRenderer::MtfRenderer" || fqn == "shell::sessioninstall::SyncDbusSessionHelper::SyncDbusSessionHelper"
 411         || fqn == "dp_gui::LicenseDialog::LicenseDialog"
 412         || fqn == "(anonymous namespace)::OGLTransitionFactoryImpl::OGLTransitionFactoryImpl")
 413          return true;
 414     // FIXME
 415     if (fqn == "GtkSalDisplay::filterGdkEvent" || fqn == "SvXMLEmbeddedObjectHelper::ImplReadObject"
 416         || fqn == "chart::CachedDataSequence::CachedDataSequence")
 417          return true;
 418     // used via macro
 419     if (fqn == "framework::MediaTypeDetectionHelper::MediaTypeDetectionHelper"
 420         || fqn == "framework::UriAbbreviation::UriAbbreviation"
 421         || fqn == "framework::DispatchDisabler::DispatchDisabler"
 422         || fqn == "framework::DispatchRecorderSupplier::DispatchRecorderSupplier")
 423          return true;
 424     // TODO Armin Le Grand is still working on this
 425     if (fqn == "svx::frame::CreateDiagFrameBorderPrimitives"
 426         || fqn == "svx::frame::CreateBorderPrimitives")
 427          return true;
 428     // marked with a TODO
 429     if (fqn == "pcr::FormLinkDialog::getExistingRelation"
 430         || fqn == "ooo::vba::DebugHelper::basicexception"
 431         || fqn == "ScPrintFunc::DrawToDev")
 432          return true;
 433     // macros at work
 434     if (fqn == "msfilter::lcl_PrintDigest")
 435          return true;
 436     // TODO something wrong here, the method that calls this (Normal::GenSlidingWindowFunction) cannot be correct
 437     if (fqn == "sc::opencl::OpBase::Gen")
 438          return true;
 439     // Can't change this without conflicting with another constructor with the same signature
 440     if (fqn == "XclExpSupbook::XclExpSupbook")
 441          return true;
 442     // ignore the LINK macros from include/tools/link.hxx
 443     if (decl->getLocation().isMacroID())
 444         return true;
 445     // debug code in sw/
 446     if (fqn == "lcl_dbg_out")
 447          return true;
 448
 449     for( auto it = decl->param_begin(); it != decl->param_end(); ++it) {
 450         auto param = *it;
 451         if (param->hasAttr<UnusedAttr>())
 452             continue;
 453         if (!param->getName().empty())
 454             continue;
 455         // ignore params which are enum types with only a single enumerator, these are marker/tag types
 456         auto paramType = param->getType();
 457         if (paramType->isEnumeralType()) {
 458             auto enumType = paramType->getAs<EnumType>();
 459             int cnt = std::distance(enumType->getDecl()->enumerator_begin(), enumType->getDecl()->enumerator_end());
 460             if (cnt == 1)
 461                 continue;
 462         }
 463         // ignore params which are a reference to a struct which has no fields.
 464         // These are either
 465         //  (a) marker/tag types
 466         //  (b) selective "friend" access
 467         if (paramType->isReferenceType()) {
 468             auto referenceType = paramType->getAs<ReferenceType>();
 469             if (referenceType->getPointeeType()->isRecordType()) {
 470                 auto recordType = referenceType->getPointeeType()->getAs<RecordType>();
 471                 if (noFieldsInRecord(recordType) == 0)
 472                     continue;
 473             }
 474         }
 475         else if (paramType->isRecordType()) {
 476             if (noFieldsInRecord(paramType->getAs<RecordType>()) == 0)
 477                 continue;
 478         }
 479         report( DiagnosticsEngine::Warning,
 480                 "unused param %0 in %1", compat::getBeginLoc(param))
 481                 << param->getSourceRange()
 482                 << param->getName()
 483                 << fqn;
 484         if (canon != decl)
 485         {
 486             unsigned idx = param->getFunctionScopeIndex();
 487             const ParmVarDecl* pOther = canon->getParamDecl(idx);
 488             report( DiagnosticsEngine::Note, "declaration is here",
 489                     compat::getBeginLoc(pOther))
 490                     << pOther->getSourceRange();
 491         }
 492     }
 493     return true;
 494 }
 495
 496 loplugin::Plugin::Registration<CheckUnusedParams> X("checkunusedparams", false);
 497
 498 }
 499
 500 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */