compilerplugins/clang/writeonlyvars.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 #if !defined _WIN32 //TODO, #include <sys/file.h>
  11
  12 #include <cassert>
  13 #include <string>
  14 #include <iostream>
  15 #include <fstream>
  16 #include <unordered_set>
  17 #include <vector>
  18 #include <algorithm>
  19 #include <sys/file.h>
  20 #include <unistd.h>
  21
  22 #include "config_clang.h"
  23
  24 #include "plugin.hxx"
  25 #include "check.hxx"
  26 #include "compat.hxx"
  27
  28 #include "clang/AST/ParentMapContext.h"
  29
  30 /**
  31   Finds variables that are effectively write-only.
  32
  33   Largely the same as the unusedfields.cxx loplugin.
  34 */
  35
  36 namespace
  37 {
  38 struct MyVarInfo
  39 {
  40     const VarDecl* varDecl;
  41     std::string parent;
  42     std::string varName;
  43     std::string varType;
  44     std::string sourceLocation;
  45 };
  46 bool operator<(const MyVarInfo& lhs, const MyVarInfo& rhs)
  47 {
  48     return std::tie(lhs.parent, lhs.varName) < std::tie(rhs.parent, rhs.varName);
  49 }
  50
  51 // try to limit the voluminous output a little
  52 static std::set<MyVarInfo> readFromSet;
  53 static std::set<MyVarInfo> writeToSet;
  54 static std::set<MyVarInfo> definitionSet;
  55
  56 /**
  57  * Wrap the different kinds of callable and callee objects in the clang AST so I can define methods that handle everything.
  58  */
  59 class CallerWrapper
  60 {
  61     const CallExpr* m_callExpr;
  62     const CXXConstructExpr* m_cxxConstructExpr;
  63
  64 public:
  65     CallerWrapper(const CallExpr* callExpr)
  66         : m_callExpr(callExpr)
  67         , m_cxxConstructExpr(nullptr)
  68     {
  69     }
  70     CallerWrapper(const CXXConstructExpr* cxxConstructExpr)
  71         : m_callExpr(nullptr)
  72         , m_cxxConstructExpr(cxxConstructExpr)
  73     {
  74     }
  75     unsigned getNumArgs() const
  76     {
  77         return m_callExpr ? m_callExpr->getNumArgs() : m_cxxConstructExpr->getNumArgs();
  78     }
  79     const Expr* getArg(unsigned i) const
  80     {
  81         return m_callExpr ? m_callExpr->getArg(i) : m_cxxConstructExpr->getArg(i);
  82     }
  83 };
  84 class CalleeWrapper
  85 {
  86     const FunctionDecl* m_calleeFunctionDecl = nullptr;
  87     const CXXConstructorDecl* m_cxxConstructorDecl = nullptr;
  88     const FunctionProtoType* m_functionPrototype = nullptr;
  89
  90 public:
  91     explicit CalleeWrapper(const FunctionDecl* calleeFunctionDecl)
  92         : m_calleeFunctionDecl(calleeFunctionDecl)
  93     {
  94     }
  95     explicit CalleeWrapper(const CXXConstructExpr* cxxConstructExpr)
  96         : m_cxxConstructorDecl(cxxConstructExpr->getConstructor())
  97     {
  98     }
  99     explicit CalleeWrapper(const FunctionProtoType* functionPrototype)
 100         : m_functionPrototype(functionPrototype)
 101     {
 102     }
 103     unsigned getNumParams() const
 104     {
 105         if (m_calleeFunctionDecl)
 106             return m_calleeFunctionDecl->getNumParams();
 107         else if (m_cxxConstructorDecl)
 108             return m_cxxConstructorDecl->getNumParams();
 109         else if (m_functionPrototype->param_type_begin() == m_functionPrototype->param_type_end())
 110             // FunctionProtoType will assert if we call getParamTypes() and it has no params
 111             return 0;
 112         else
 113             return m_functionPrototype->getParamTypes().size();
 114     }
 115     const QualType getParamType(unsigned i) const
 116     {
 117         if (m_calleeFunctionDecl)
 118             return m_calleeFunctionDecl->getParamDecl(i)->getType();
 119         else if (m_cxxConstructorDecl)
 120             return m_cxxConstructorDecl->getParamDecl(i)->getType();
 121         else
 122             return m_functionPrototype->getParamTypes()[i];
 123     }
 124     std::string getNameAsString() const
 125     {
 126         if (m_calleeFunctionDecl)
 127             return m_calleeFunctionDecl->getNameAsString();
 128         else if (m_cxxConstructorDecl)
 129             return m_cxxConstructorDecl->getNameAsString();
 130         else
 131             return "";
 132     }
 133     CXXMethodDecl const* getAsCXXMethodDecl() const
 134     {
 135         if (m_calleeFunctionDecl)
 136             return dyn_cast<CXXMethodDecl>(m_calleeFunctionDecl);
 137         return nullptr;
 138     }
 139 };
 140
 141 class WriteOnlyVars : public loplugin::FilteringPlugin<WriteOnlyVars>
 142 {
 143 public:
 144     explicit WriteOnlyVars(loplugin::InstantiationData const& data)
 145         : FilteringPlugin(data)
 146     {
 147     }
 148
 149     virtual void run() override;
 150
 151     bool shouldVisitTemplateInstantiations() const { return true; }
 152     bool shouldVisitImplicitCode() const { return true; }
 153
 154     bool VisitVarDecl(const VarDecl*);
 155     bool VisitDeclRefExpr(const DeclRefExpr*);
 156     bool TraverseIfStmt(IfStmt*);
 157
 158 private:
 159     MyVarInfo niceName(const VarDecl*);
 160     void checkIfReadFrom(const VarDecl* varDecl, const Expr* memberExpr);
 161     void checkIfWrittenTo(const VarDecl* varDecl, const Expr* memberExpr);
 162     bool checkForWriteWhenUsingCollectionType(const CXXMethodDecl* calleeMethodDecl);
 163     bool IsPassedByNonConst(const VarDecl* varDecl, const Stmt* child, CallerWrapper callExpr,
 164                             CalleeWrapper calleeFunctionDecl);
 165     compat::optional<CalleeWrapper> getCallee(CallExpr const*);
 166
 167     // For reasons I do not understand, parentFunctionDecl() is not reliable, so
 168     // we store the parent function on the way down the AST.
 169     FunctionDecl* insideFunctionDecl = nullptr;
 170     std::vector<VarDecl const*> insideConditionalCheckOfMemberSet;
 171 };
 172
 173 void WriteOnlyVars::run()
 174 {
 175     TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
 176
 177     if (!isUnitTestMode())
 178     {
 179         StringRef fn(handler.getMainFileName());
 180         // playing paging-in games with volatile
 181         if (loplugin::isSamePathname(fn, SRCDIR "/sal/osl/unx/file.cxx"))
 182             return;
 183         // playing paging-in games with volatile
 184         if (loplugin::isSamePathname(fn, SRCDIR "/desktop/unx/source/file_image_unx.c"))
 185             return;
 186         // false+
 187         if (loplugin::isSamePathname(fn, SRCDIR "/store/source/storpage.cxx"))
 188             return;
 189         if (fn.contains("/qa/"))
 190             return;
 191         if (fn.contains("/vcl/workben/"))
 192             return;
 193         // preload
 194         if (loplugin::isSamePathname(fn, SRCDIR "/cppuhelper/source/servicemanager.cxx"))
 195             return;
 196         // doing a "free items outside lock" thing
 197         if (loplugin::isSamePathname(fn, SRCDIR "/unotools/source/config/itemholder1.cxx"))
 198             return;
 199         if (loplugin::isSamePathname(fn, SRCDIR "/svl/source/config/itemholder2.cxx"))
 200             return;
 201         if (loplugin::isSamePathname(fn, SRCDIR "/svtools/source/config/itemholder2.cxx"))
 202             return;
 203         // doing a "keep objects alive" thing
 204         if (loplugin::isSamePathname(fn, SRCDIR "/jvmfwk/source/framework.cxx"))
 205             return;
 206         if (loplugin::isSamePathname(fn, SRCDIR "/jvmfwk/plugins/sunmajor/pluginlib/util.cxx"))
 207             return;
 208         // debug code
 209         if (loplugin::isSamePathname(fn, SRCDIR "/svl/source/items/style.cxx"))
 210             return;
 211         // ok
 212         if (loplugin::isSamePathname(fn, SRCDIR "/stoc/source/inspect/introspection.cxx"))
 213             return;
 214         if (loplugin::isSamePathname(fn, SRCDIR "/package/source/zippackage/ZipPackage.cxx"))
 215             return;
 216         if (loplugin::isSamePathname(fn, SRCDIR "/hwpfilter/source/hwpreader.cxx"))
 217             return;
 218         if (loplugin::isSamePathname(fn, SRCDIR "/vcl/source/treelist/transfer.cxx"))
 219             return;
 220         if (loplugin::isSamePathname(fn, SRCDIR "/vcl/source/app/brand.cxx"))
 221             return;
 222         if (loplugin::isSamePathname(fn, SRCDIR "/vcl/source/filter/igif/gifread.cxx"))
 223             return;
 224         if (loplugin::isSamePathname(fn, SRCDIR "/vcl/source/gdi/metaact.cxx"))
 225             return;
 226         if (loplugin::isSamePathname(fn, SRCDIR "/vcl/source/fontsubset/sft.cxx"))
 227             return;
 228         if (loplugin::isSamePathname(fn, SRCDIR "/vcl/source/filter/ipdf/pdfdocument.cxx"))
 229             return;
 230         if (loplugin::isSamePathname(fn, SRCDIR "/vcl/source/filter/ipdf/pdfdocument2.cxx"))
 231             return;
 232         if (loplugin::isSamePathname(fn, SRCDIR "/vcl/unx/generic/app/sm.cxx"))
 233             return;
 234         if (loplugin::isSamePathname(fn, SRCDIR "/vcl/source/filter/jpeg/JpegWriter.cxx"))
 235             return;
 236         if (loplugin::isSamePathname(fn, SRCDIR "/vcl/unx/generic/dtrans/X11_selection.cxx"))
 237             return;
 238         if (loplugin::isSamePathname(fn, SRCDIR "/vcl/source/filter/jpeg/jpegc.cxx"))
 239             return;
 240         if (loplugin::isSamePathname(fn, SRCDIR "/vcl/unx/generic/window/FWS.cxx"))
 241             return;
 242         if (loplugin::isSamePathname(fn, SRCDIR "/toolkit/source/awt/vclxspinbutton.cxx"))
 243             return;
 244         if (loplugin::isSamePathname(fn, SRCDIR "/toolkit/source/controls/formattedcontrol.cxx"))
 245             return;
 246         if (loplugin::isSamePathname(fn, SRCDIR "/svtools/source/config/helpopt.cxx"))
 247             return;
 248         if (loplugin::isSamePathname(fn, SRCDIR "/svtools/source/filter/SvFilterOptionsDialog.cxx"))
 249             return;
 250         if (loplugin::isSamePathname(fn, SRCDIR "/svtools/source/java/javainteractionhandler.cxx"))
 251             return;
 252         if (loplugin::isSamePathname(fn, SRCDIR "/basic/source/classes/sbunoobj.cxx"))
 253             return;
 254         if (loplugin::isSamePathname(fn,
 255                                      SRCDIR "/accessibility/source/standard/vclxaccessiblebox.cxx"))
 256             return;
 257         if (loplugin::isSamePathname(fn, SRCDIR "/cppcanvas/source/mtfrenderer/implrenderer.cxx"))
 258             return;
 259         if (loplugin::isSamePathname(fn, SRCDIR "/sfx2/source/doc/guisaveas.cxx"))
 260             return;
 261         if (loplugin::isSamePathname(fn, SRCDIR "/sfx2/source/appl/newhelp.cxx"))
 262             return;
 263         if (loplugin::isSamePathname(fn, SRCDIR "/sfx2/source/control/thumbnailview.cxx"))
 264             return;
 265         if (loplugin::isSamePathname(fn, SRCDIR "/sfx2/source/control/recentdocsview.cxx"))
 266             return;
 267         if (loplugin::isSamePathname(fn, SRCDIR "/sfx2/source/view/viewfrm.cxx"))
 268             return;
 269         if (loplugin::isSamePathname(fn, SRCDIR "/framework/source/services/desktop.cxx"))
 270             return;
 271         if (loplugin::isSamePathname(fn, SRCDIR
 272                                      "/framework/source/uielement/generictoolbarcontroller.cxx"))
 273             return;
 274         if (loplugin::isSamePathname(fn, SRCDIR
 275                                      "/framework/source/uielement/complextoolbarcontroller.cxx"))
 276             return;
 277         if (loplugin::isSamePathname(fn,
 278                                      SRCDIR "/framework/source/interaction/quietinteraction.cxx"))
 279             return;
 280         if (loplugin::isSamePathname(fn, SRCDIR "/editeng/source/editeng/editdoc.cxx"))
 281             return;
 282         if (loplugin::isSamePathname(fn, SRCDIR "/editeng/source/editeng/impedit4.cxx"))
 283             return;
 284         if (loplugin::isSamePathname(fn, SRCDIR "/editeng/source/editeng/editobj.cxx"))
 285             return;
 286         if (loplugin::isSamePathname(fn, SRCDIR "/editeng/source/items/frmitems.cxx"))
 287             return;
 288         if (loplugin::isSamePathname(fn, SRCDIR "/binaryurp/source/bridge.cxx"))
 289             return;
 290         if (loplugin::isSamePathname(fn, SRCDIR "/svx/source/tbxctrls/fontworkgallery.cxx"))
 291             return;
 292         if (loplugin::isSamePathname(fn, SRCDIR "/basctl/source/basicide/moduldl2.cxx"))
 293             return;
 294         if (loplugin::isSamePathname(fn, SRCDIR "/canvas/source/cairo/cairo_spritecanvas.cxx"))
 295             return;
 296         if (loplugin::isSamePathname(fn, SRCDIR "/chart2/source/tools/DiagramHelper.cxx"))
 297             return;
 298         if (loplugin::isSamePathname(fn,
 299                                      SRCDIR "/chart2/source/tools/ExplicitCategoriesProvider.cxx"))
 300             return;
 301         if (loplugin::isSamePathname(fn, SRCDIR "/chart2/source/tools/LegendHelper.cxx"))
 302             return;
 303         if (loplugin::isSamePathname(fn, SRCDIR "/chart2/source/tools/OPropertySet.cxx"))
 304             return;
 305         if (loplugin::isSamePathname(fn, SRCDIR "/chart2/source/tools/CommonConverters.cxx"))
 306             return;
 307         if (loplugin::isSamePathname(
 308                 fn,
 309                 SRCDIR "/chart2/source/controller/chartapiwrapper/WrappedNumberFormatProperty.cxx"))
 310             return;
 311         if (loplugin::isSamePathname(fn, SRCDIR "/chart2/source/tools/DataSourceHelper.cxx"))
 312             return;
 313         if (loplugin::isSamePathname(fn, SRCDIR "/oox/source/export/shapes.cxx"))
 314             return;
 315         if (loplugin::isSamePathname(fn, SRCDIR "/oox/source/export/chartexport.cxx"))
 316             return;
 317         if (loplugin::isSamePathname(fn,
 318                                      SRCDIR "/filter/source/storagefilterdetect/filterdetect.cxx"))
 319             return;
 320         if (loplugin::isSamePathname(fn, SRCDIR "/filter/source/pdf/pdfexport.cxx"))
 321             return;
 322         if (loplugin::isSamePathname(fn, SRCDIR "/filter/source/svg/svgexport.cxx"))
 323             return;
 324         if (loplugin::isSamePathname(fn, SRCDIR "/filter/source/msfilter/svdfppt.cxx"))
 325             return;
 326         if (loplugin::isSamePathname(fn, SRCDIR
 327                                      "/dbaccess/source/core/recovery/subcomponentrecovery.cxx"))
 328             return;
 329         if (loplugin::isSamePathname(fn, SRCDIR
 330                                      "/dbaccess/source/core/dataaccess/documentcontainer.cxx"))
 331             return;
 332         if (loplugin::isSamePathname(fn, SRCDIR
 333                                      "/dbaccess/source/core/dataaccess/databasedocument.cxx"))
 334             return;
 335         if (loplugin::isSamePathname(fn,
 336                                      SRCDIR "/dbaccess/source/ui/browser/genericcontroller.cxx"))
 337             return;
 338         if (loplugin::isSamePathname(fn, SRCDIR "/ucb/source/core/ucbcmds.cxx"))
 339             return;
 340         if (loplugin::isSamePathname(fn,
 341                                      SRCDIR "/desktop/source/deployment/manager/dp_manager.cxx"))
 342             return;
 343         if (loplugin::isSamePathname(fn, SRCDIR
 344                                      "/desktop/source/deployment/registry/package/dp_package.cxx"))
 345             return;
 346         if (loplugin::isSamePathname(fn, SRCDIR "/desktop/source/lib/init.cxx"))
 347             return;
 348         if (loplugin::isSamePathname(fn, SRCDIR
 349                                      "/extensions/source/propctrlr/formcomponenthandler.cxx"))
 350             return;
 351         if (loplugin::isSamePathname(fn, SRCDIR "/embeddedobj/source/general/docholder.cxx"))
 352             return;
 353         if (loplugin::isSamePathname(fn, SRCDIR
 354                                      "/extensions/source/propctrlr/stringrepresentation.cxx"))
 355             return;
 356         if (loplugin::isSamePathname(fn, SRCDIR "/lotuswordpro/source/filter/lwpcontent.cxx"))
 357             return;
 358         if (loplugin::isSamePathname(fn, SRCDIR "/lotuswordpro/source/filter/lwpdivinfo.cxx"))
 359             return;
 360         if (loplugin::isSamePathname(fn, SRCDIR "/lotuswordpro/source/filter/lwpdoc.cxx"))
 361             return;
 362         if (loplugin::isSamePathname(fn, SRCDIR "/filter/source/pdf/impdialog.cxx"))
 363             return;
 364         if (loplugin::isSamePathname(fn, SRCDIR "/lotuswordpro/source/filter/lwplayout.cxx"))
 365             return;
 366         if (loplugin::isSamePathname(fn, SRCDIR "/lotuswordpro/source/filter/lwpoleobject.cxx"))
 367             return;
 368         if (loplugin::isSamePathname(fn, SRCDIR "/lotuswordpro/source/filter/lwprowlayout.cxx"))
 369             return;
 370         if (loplugin::isSamePathname(fn, SRCDIR "/lotuswordpro/source/filter/lwpfoundry.cxx"))
 371             return;
 372         if (loplugin::isSamePathname(fn, SRCDIR "/lotuswordpro/source/filter/lwpparastyle.cxx"))
 373             return;
 374         if (loplugin::isSamePathname(fn, SRCDIR "/lotuswordpro/source/filter/lwpnotes.cxx"))
 375             return;
 376         if (loplugin::isSamePathname(fn, SRCDIR "/lotuswordpro/source/filter/lwpfont.cxx"))
 377             return;
 378         if (loplugin::isSamePathname(fn, SRCDIR "/lotuswordpro/source/filter/lwptblcell.cxx"))
 379             return;
 380         if (loplugin::isSamePathname(fn, SRCDIR "/lotuswordpro/source/filter/lwpusrdicts.cxx"))
 381             return;
 382         if (loplugin::isSamePathname(fn, SRCDIR "/lotuswordpro/source/filter/lwpverdocument.cxx"))
 383             return;
 384         if (loplugin::isSamePathname(fn, SRCDIR "/lotuswordpro/source/filter/lwptblformula.cxx"))
 385             return;
 386         if (loplugin::isSamePathname(fn, SRCDIR "/vbahelper/source/vbahelper/vbafontbase.cxx"))
 387             return;
 388         if (loplugin::isSamePathname(fn, SRCDIR "/vbahelper/source/vbahelper/vbadocumentbase.cxx"))
 389             return;
 390         if (loplugin::isSamePathname(fn, SRCDIR "/sc/source/ui/docshell/docsh8.cxx"))
 391             return;
 392         if (loplugin::isSamePathname(fn, SRCDIR "/sc/source/ui/docshell/docsh6.cxx"))
 393             return;
 394         if (loplugin::isSamePathname(fn, SRCDIR "/sc/source/core/data/table3.cxx"))
 395             return;
 396         if (loplugin::isSamePathname(fn, SRCDIR "/sc/source/ui/unoobj/cellsuno.cxx"))
 397             return;
 398         if (loplugin::isSamePathname(fn, SRCDIR "/sc/source/filter/excel/xelink.cxx"))
 399             return;
 400         if (loplugin::isSamePathname(fn, SRCDIR "/sc/source/filter/lotus/lotus.cxx"))
 401             return;
 402         if (loplugin::isSamePathname(fn, SRCDIR "/sc/source/ui/vba/vbaworkbooks.cxx"))
 403             return;
 404         if (loplugin::isSamePathname(fn, SRCDIR "/sc/source/ui/vba/vbaworksheets.cxx"))
 405             return;
 406         if (loplugin::isSamePathname(fn, SRCDIR "/sc/source/ui/vba/vbarange.cxx"))
 407             return;
 408         if (loplugin::isSamePathname(fn, SRCDIR "/sd/source/ui/view/drviews2.cxx"))
 409             return;
 410         if (loplugin::isSamePathname(fn, SRCDIR "/sd/source/filter/ppt/pptin.cxx"))
 411             return;
 412         if (loplugin::isSamePathname(fn, SRCDIR "/sd/source/ui/app/sdxfer.cxx"))
 413             return;
 414         if (loplugin::isSamePathname(fn, SRCDIR "/sd/source/ui/view/drviewsf.cxx"))
 415             return;
 416         if (loplugin::isSamePathname(fn, SRCDIR "/sd/source/filter/xml/sdxmlwrp.cxx"))
 417             return;
 418         if (loplugin::isSamePathname(fn, SRCDIR "/sd/source/filter/html/pubdlg.cxx"))
 419             return;
 420         if (loplugin::isSamePathname(fn, SRCDIR "/sw/source/core/txtnode/thints.cxx"))
 421             return;
 422         if (loplugin::isSamePathname(fn, SRCDIR "/sw/source/core/doc/docbm.cxx"))
 423             return;
 424         if (loplugin::isSamePathname(fn, SRCDIR "/sw/source/core/crsr/crsrsh.cxx"))
 425             return;
 426         if (loplugin::isSamePathname(fn, SRCDIR "/sw/source/filter/xml/swxml.cxx"))
 427             return;
 428         if (loplugin::isSamePathname(fn, SRCDIR "/sw/source/core/doc/docredln.cxx"))
 429             return;
 430         if (loplugin::isSamePathname(fn, SRCDIR "/sw/source/filter/ww8/ww8par2.cxx"))
 431             return;
 432         if (loplugin::isSamePathname(fn, SRCDIR "/sw/source/uibase/shells/drformsh.cxx"))
 433             return;
 434         if (loplugin::isSamePathname(fn, SRCDIR "/sw/source/filter/ww8/ww8par6.cxx"))
 435             return;
 436         if (loplugin::isSamePathname(fn, SRCDIR "/sw/source/ui/dbui/dbinsdlg.cxx"))
 437             return;
 438         if (loplugin::isSamePathname(fn, SRCDIR "/sdext/source/minimizer/impoptimizer.cxx"))
 439             return;
 440         if (loplugin::isSamePathname(fn, SRCDIR "/sdext/source/presenter/PresenterTheme.cxx"))
 441             return;
 442         if (loplugin::isSamePathname(fn, SRCDIR "/sdext/source/pdfimport/wrapper/wrapper.cxx"))
 443             return;
 444         if (loplugin::isSamePathname(fn, SRCDIR
 445                                      "/slideshow/source/engine/animationnodes/generateevent.cxx"))
 446             return;
 447         if (loplugin::isSamePathname(fn, SRCDIR "/starmath/source/mathmlimport.cxx"))
 448             return;
 449         if (loplugin::isSamePathname(fn, SRCDIR "/starmath/source/eqnolefilehdr.cxx"))
 450             return;
 451         if (loplugin::isSamePathname(fn, SRCDIR "/svgio/source/svgreader/svgmarkernode.cxx"))
 452             return;
 453         if (loplugin::isSamePathname(fn, SRCDIR "/uui/source/iahndl-locking.cxx"))
 454             return;
 455         if (loplugin::isSamePathname(fn, SRCDIR
 456                                      "/shell/source/sessioninstall/SyncDbusSessionHelper.cxx"))
 457             return;
 458         if (loplugin::isSamePathname(fn,
 459                                      SRCDIR "/slideshow/source/engine/opengl/TransitionerImpl.cxx"))
 460             return;
 461         if (loplugin::isSamePathname(fn, SRCDIR "/forms/source/component/FormattedField.cxx"))
 462             return;
 463         if (loplugin::isSamePathname(fn, SRCDIR "/forms/source/component/DatabaseForm.cxx"))
 464             return;
 465         if (loplugin::isSamePathname(fn,
 466                                      SRCDIR "/reportdesign/source/ui/report/ReportController.cxx"))
 467             return;
 468         if (loplugin::hasPathnamePrefix(fn, SRCDIR "/test/"))
 469             return;
 470         if (loplugin::isSamePathname(fn, SRCDIR "/i18npool/source/localedata/LocaleNode.cxx"))
 471             return;
 472
 473         // yynerrs?
 474         if (loplugin::isSamePathname(fn, SRCDIR "/hwpfilter/source/grammar.cxx"))
 475             return;
 476
 477         for (MyVarInfo const& v : definitionSet)
 478         {
 479             bool read = readFromSet.find(v) != readFromSet.end();
 480             bool write = writeToSet.find(v) != writeToSet.end();
 481             if (!read && write)
 482                 report(DiagnosticsEngine::Warning, "write-only %0", v.varDecl->getBeginLoc())
 483                     << v.varName;
 484         }
 485     }
 486     else
 487     {
 488         for (const MyVarInfo& s : readFromSet)
 489             report(DiagnosticsEngine::Warning, "read %0", s.varDecl->getBeginLoc()) << s.varName;
 490         for (const MyVarInfo& s : writeToSet)
 491             report(DiagnosticsEngine::Warning, "write %0", s.varDecl->getBeginLoc()) << s.varName;
 492     }
 493 }
 494
 495 MyVarInfo WriteOnlyVars::niceName(const VarDecl* varDecl)
 496 {
 497     MyVarInfo aInfo;
 498
 499     aInfo.varDecl = varDecl->getCanonicalDecl();
 500     aInfo.varName = varDecl->getNameAsString();
 501     // sometimes the name (if it's an anonymous thing) contains the full path of the build folder, which we don't need
 502     size_t idx = aInfo.varName.find(SRCDIR);
 503     if (idx != std::string::npos)
 504     {
 505         aInfo.varName = aInfo.varName.replace(idx, strlen(SRCDIR), "");
 506     }
 507     aInfo.varType = varDecl->getType().getAsString();
 508
 509     SourceLocation expansionLoc
 510         = compiler.getSourceManager().getExpansionLoc(varDecl->getLocation());
 511     StringRef filename = getFilenameOfLocation(expansionLoc);
 512     aInfo.sourceLocation
 513         = std::string(filename.substr(strlen(SRCDIR) + 1)) + ":"
 514           + std::to_string(compiler.getSourceManager().getSpellingLineNumber(expansionLoc));
 515     loplugin::normalizeDotDotInFilePath(aInfo.sourceLocation);
 516     aInfo.parent = filename.str();
 517
 518     return aInfo;
 519 }
 520
 521 static bool contains(std::string const& s, std::string const& needle)
 522 {
 523     return s.find(needle) != std::string::npos;
 524 }
 525
 526 bool WriteOnlyVars::VisitVarDecl(const VarDecl* varDecl)
 527 {
 528     if (varDecl->isImplicit() || varDecl->isExternC() || isa<ParmVarDecl>(varDecl))
 529         return true;
 530     auto tc = loplugin::TypeCheck(varDecl->getType());
 531     if (tc.Pointer() || tc.LvalueReference() || tc.Class("shared_ptr").StdNamespace()
 532         || tc.Class("unique_ptr").StdNamespace())
 533         return true;
 534     if (tc.Typedef("BitmapScopedWriteAccess"))
 535         return true;
 536     std::string typeName = varDecl->getType().getAsString();
 537     if (contains(typeName, "Guard") || contains(typeName, "Reader") || contains(typeName, "Stream")
 538         || contains(typeName, "Parser") || contains(typeName, "Codec")
 539         || contains(typeName, "Exception"))
 540         return true;
 541     varDecl = varDecl->getCanonicalDecl();
 542     if (!varDecl->getLocation().isValid() || ignoreLocation(varDecl))
 543         return true;
 544     if (!compiler.getSourceManager().isInMainFile(varDecl->getLocation()))
 545         return true;
 546     if (compiler.getSourceManager().isMacroBodyExpansion(varDecl->getBeginLoc()))
 547         return true;
 548     if (compiler.getSourceManager().isMacroArgExpansion(varDecl->getBeginLoc()))
 549         return true;
 550     // ignore stuff that forms part of the stable URE interface
 551     if (isInUnoIncludeFile(compiler.getSourceManager().getSpellingLoc(varDecl->getLocation())))
 552         return true;
 553
 554     definitionSet.insert(niceName(varDecl));
 555     return true;
 556 }
 557
 558 static char easytolower(char in)
 559 {
 560     if (in <= 'Z' && in >= 'A')
 561         return in - ('Z' - 'z');
 562     return in;
 563 }
 564
 565 bool startswith(const std::string& rStr, const char* pSubStr)
 566 {
 567     return rStr.compare(0, strlen(pSubStr), pSubStr) == 0;
 568 }
 569
 570 bool WriteOnlyVars::TraverseIfStmt(IfStmt* ifStmt)
 571 {
 572     VarDecl const* varDecl = nullptr;
 573     Expr const* cond = ifStmt->getCond()->IgnoreParenImpCasts();
 574     if (auto declRefExpr = dyn_cast<DeclRefExpr>(cond))
 575     {
 576         if ((varDecl = dyn_cast<VarDecl>(declRefExpr->getDecl())))
 577             insideConditionalCheckOfMemberSet.push_back(varDecl);
 578     }
 579     bool ret = RecursiveASTVisitor::TraverseIfStmt(ifStmt);
 580     if (varDecl)
 581         insideConditionalCheckOfMemberSet.pop_back();
 582     return ret;
 583 }
 584
 585 void WriteOnlyVars::checkIfReadFrom(const VarDecl* varDecl, const Expr* memberExpr)
 586 {
 587     auto parentsRange = compiler.getASTContext().getParents(*memberExpr);
 588     const Stmt* child = memberExpr;
 589     const Stmt* parent
 590         = parentsRange.begin() == parentsRange.end() ? nullptr : parentsRange.begin()->get<Stmt>();
 591     // walk up the tree until we find something interesting
 592     bool bPotentiallyReadFrom = false;
 593     bool bDump = false;
 594     auto walkupUp = [&]() {
 595         child = parent;
 596         auto parentsRange = compiler.getASTContext().getParents(*parent);
 597         parent = parentsRange.begin() == parentsRange.end() ? nullptr
 598                                                             : parentsRange.begin()->get<Stmt>();
 599     };
 600     do
 601     {
 602         if (!parent)
 603         {
 604             // check if we're inside a CXXCtorInitializer or a VarDecl
 605             auto parentsRange = compiler.getASTContext().getParents(*child);
 606             if (parentsRange.begin() != parentsRange.end())
 607             {
 608                 const Decl* decl = parentsRange.begin()->get<Decl>();
 609                 if (decl && (isa<CXXConstructorDecl>(decl) || isa<VarDecl>(decl)))
 610                     bPotentiallyReadFrom = true;
 611             }
 612             if (!bPotentiallyReadFrom)
 613                 return;
 614             break;
 615         }
 616         if (isa<CXXReinterpretCastExpr>(parent))
 617         {
 618             // once we see one of these, there is not much useful we can know
 619             bPotentiallyReadFrom = true;
 620             break;
 621         }
 622         else if (isa<CastExpr>(parent) || isa<MemberExpr>(parent) || isa<ParenExpr>(parent)
 623                  || isa<ParenListExpr>(parent) || isa<ArrayInitLoopExpr>(parent)
 624                  || isa<ExprWithCleanups>(parent))
 625         {
 626             walkupUp();
 627         }
 628         else if (auto unaryOperator = dyn_cast<UnaryOperator>(parent))
 629         {
 630             UnaryOperator::Opcode op = unaryOperator->getOpcode();
 631             if (memberExpr->getType()->isArrayType() && op == UO_Deref)
 632             {
 633                 // ignore, deref'ing an array does not count as a read
 634             }
 635             else if (op == UO_AddrOf || op == UO_Deref || op == UO_Plus || op == UO_Minus
 636                      || op == UO_Not || op == UO_LNot)
 637             {
 638                 bPotentiallyReadFrom = true;
 639                 break;
 640             }
 641             /* The following are technically reads, but from a code-sense they're more of a write/modify, so
 642                 ignore them to find interesting fields that only modified, not usefully read:
 643                 UO_PreInc / UO_PostInc / UO_PreDec / UO_PostDec
 644                 But we still walk up in case the result of the expression is used in a read sense.
 645             */
 646             walkupUp();
 647         }
 648         else if (auto caseStmt = dyn_cast<CaseStmt>(parent))
 649         {
 650             bPotentiallyReadFrom = caseStmt->getLHS() == child || caseStmt->getRHS() == child;
 651             break;
 652         }
 653         else if (auto ifStmt = dyn_cast<IfStmt>(parent))
 654         {
 655             bPotentiallyReadFrom = ifStmt->getCond() == child;
 656             break;
 657         }
 658         else if (auto doStmt = dyn_cast<DoStmt>(parent))
 659         {
 660             bPotentiallyReadFrom = doStmt->getCond() == child;
 661             break;
 662         }
 663         else if (auto arraySubscriptExpr = dyn_cast<ArraySubscriptExpr>(parent))
 664         {
 665             if (arraySubscriptExpr->getIdx() == child)
 666             {
 667                 bPotentiallyReadFrom = true;
 668                 break;
 669             }
 670             walkupUp();
 671         }
 672         else if (auto callExpr = dyn_cast<CXXMemberCallExpr>(parent))
 673         {
 674             // check for calls to ReadXXX() type methods and the operator>>= methods on Any.
 675             auto callee = getCallee(callExpr);
 676             if (callee && *callExpr->child_begin() == child)
 677             {
 678                 // FIXME perhaps a better solution here would be some kind of SAL_PARAM_WRITEONLY attribute
 679                 // which we could scatter around.
 680                 std::string name = callee->getNameAsString();
 681                 std::transform(name.begin(), name.end(), name.begin(), easytolower);
 682                 if (startswith(name, "read"))
 683                     // this is a write-only call
 684                     ;
 685                 else if (startswith(name, "emplace") || name == "insert" || name == "erase"
 686                          || name == "remove" || name == "remove_if" || name == "sort"
 687                          || name == "push_back" || name == "pop_back" || name == "push_front"
 688                          || name == "pop_front" || name == "reserve" || name == "resize"
 689                          || name == "clear" || name == "fill")
 690                     // write-only modifications to collections
 691                     ;
 692                 else if (name.find(">>=") != std::string::npos && callExpr->getArg(1) == child)
 693                     // this is a write-only call
 694                     ;
 695                 else if (name == "dispose" || name == "disposeAndClear" || name == "swap")
 696                     // we're abusing the write-only analysis here to look for vars which don't have anything useful
 697                     // being done to them, so we're ignoring things like std::vector::clear, std::vector::swap,
 698                     // and VclPtr::disposeAndClear
 699                     ;
 700                 else
 701                     bPotentiallyReadFrom = true;
 702             }
 703             else
 704                 bPotentiallyReadFrom = true;
 705             break;
 706         }
 707         else if (auto callExpr = dyn_cast<CallExpr>(parent))
 708         {
 709             // check for calls to ReadXXX() type methods and the operator>>= methods on Any.
 710             auto callee = getCallee(callExpr);
 711             if (callee)
 712             {
 713                 // FIXME perhaps a better solution here would be some kind of SAL_PARAM_WRITEONLY attribute
 714                 // which we could scatter around.
 715                 std::string name = callee->getNameAsString();
 716                 std::transform(name.begin(), name.end(), name.begin(), easytolower);
 717                 if (startswith(name, "read"))
 718                     // this is a write-only call
 719                     ;
 720                 else if (name.find(">>=") != std::string::npos && callExpr->getArg(1) == child)
 721                     // this is a write-only call
 722                     ;
 723                 else
 724                     bPotentiallyReadFrom = true;
 725             }
 726             else
 727                 bPotentiallyReadFrom = true;
 728             break;
 729         }
 730         else if (auto binaryOp = dyn_cast<BinaryOperator>(parent))
 731         {
 732             BinaryOperator::Opcode op = binaryOp->getOpcode();
 733             // If the child is on the LHS and it is an assignment op, we are obviously not reading from it
 734             const bool assignmentOp = op == BO_Assign || op == BO_MulAssign || op == BO_DivAssign
 735                                       || op == BO_RemAssign || op == BO_AddAssign
 736                                       || op == BO_SubAssign || op == BO_ShlAssign
 737                                       || op == BO_ShrAssign || op == BO_AndAssign
 738                                       || op == BO_XorAssign || op == BO_OrAssign;
 739             if (!(binaryOp->getLHS() == child && assignmentOp))
 740             {
 741                 bPotentiallyReadFrom = true;
 742             }
 743             break;
 744         }
 745         else if (isa<ReturnStmt>(parent) || isa<CXXConstructExpr>(parent)
 746                  || isa<ConditionalOperator>(parent) || isa<SwitchStmt>(parent)
 747                  || isa<DeclStmt>(parent) || isa<WhileStmt>(parent) || isa<CXXNewExpr>(parent)
 748                  || isa<ForStmt>(parent) || isa<InitListExpr>(parent)
 749                  || isa<CXXDependentScopeMemberExpr>(parent) || isa<UnresolvedMemberExpr>(parent)
 750                  || isa<MaterializeTemporaryExpr>(parent))
 751         {
 752             bPotentiallyReadFrom = true;
 753             break;
 754         }
 755         else if (isa<CXXDeleteExpr>(parent) || isa<UnaryExprOrTypeTraitExpr>(parent)
 756                  || isa<CXXUnresolvedConstructExpr>(parent) || isa<CompoundStmt>(parent)
 757                  || isa<LabelStmt>(parent) || isa<CXXForRangeStmt>(parent)
 758                  || isa<CXXTypeidExpr>(parent) || isa<DefaultStmt>(parent)
 759                  || isa<GCCAsmStmt>(parent) || isa<VAArgExpr>(parent) || isa<ConstantExpr>(parent)
 760                  || isa<CXXDefaultArgExpr>(parent) || isa<LambdaExpr>(parent))
 761         {
 762             break;
 763         }
 764         else
 765         {
 766             bPotentiallyReadFrom = true;
 767             bDump = true;
 768             break;
 769         }
 770     } while (true);
 771
 772     if (bDump)
 773     {
 774         report(DiagnosticsEngine::Warning, "oh dear, what can the matter be?",
 775                memberExpr->getBeginLoc())
 776             << memberExpr->getSourceRange();
 777         report(DiagnosticsEngine::Note, "parent over here", parent->getBeginLoc())
 778             << parent->getSourceRange();
 779         parent->dump();
 780         memberExpr->dump();
 781     }
 782
 783     MyVarInfo varInfo = niceName(varDecl);
 784     if (bPotentiallyReadFrom)
 785     {
 786         readFromSet.insert(varInfo);
 787     }
 788 }
 789
 790 void WriteOnlyVars::checkIfWrittenTo(const VarDecl* varDecl, const Expr* memberExpr)
 791 {
 792     // if we're inside a block that looks like
 793     //   if (varDecl)
 794     //       ...
 795     // then writes to this var don't matter, because unless we find another write to this var, this var is dead
 796     if (std::find(insideConditionalCheckOfMemberSet.begin(),
 797                   insideConditionalCheckOfMemberSet.end(), varDecl)
 798         != insideConditionalCheckOfMemberSet.end())
 799         return;
 800
 801     auto parentsRange = compiler.getASTContext().getParents(*memberExpr);
 802     const Stmt* child = memberExpr;
 803     const Stmt* parent
 804         = parentsRange.begin() == parentsRange.end() ? nullptr : parentsRange.begin()->get<Stmt>();
 805     // walk up the tree until we find something interesting
 806     bool bPotentiallyWrittenTo = false;
 807     bool bDump = false;
 808     auto walkupUp = [&]() {
 809         child = parent;
 810         auto parentsRange = compiler.getASTContext().getParents(*parent);
 811         parent = parentsRange.begin() == parentsRange.end() ? nullptr
 812                                                             : parentsRange.begin()->get<Stmt>();
 813     };
 814     do
 815     {
 816         if (!parent)
 817         {
 818             // check if we have an expression like
 819             //    int& r = var;
 820             auto parentsRange = compiler.getASTContext().getParents(*child);
 821             if (parentsRange.begin() != parentsRange.end())
 822             {
 823                 auto varDecl = dyn_cast_or_null<VarDecl>(parentsRange.begin()->get<Decl>());
 824                 // The isImplicit() call is to avoid triggering when we see the vardecl which is part of a for-range statement,
 825                 // which is of type 'T&&' and also an l-value-ref ?
 826                 if (varDecl && !varDecl->isImplicit()
 827                     && loplugin::TypeCheck(varDecl->getType()).LvalueReference().NonConst())
 828                 {
 829                     bPotentiallyWrittenTo = true;
 830                 }
 831             }
 832             break;
 833         }
 834         if (isa<CXXReinterpretCastExpr>(parent))
 835         {
 836             // once we see one of these, there is not much useful we can know
 837             bPotentiallyWrittenTo = true;
 838             break;
 839         }
 840         else if (isa<CastExpr>(parent) || isa<MemberExpr>(parent) || isa<ParenExpr>(parent)
 841                  || isa<ParenListExpr>(parent) || isa<ArrayInitLoopExpr>(parent)
 842                  || isa<ExprWithCleanups>(parent))
 843         {
 844             walkupUp();
 845         }
 846         else if (auto unaryOperator = dyn_cast<UnaryOperator>(parent))
 847         {
 848             UnaryOperator::Opcode op = unaryOperator->getOpcode();
 849             if (op == UO_AddrOf || op == UO_PostInc || op == UO_PostDec || op == UO_PreInc
 850                 || op == UO_PreDec)
 851             {
 852                 bPotentiallyWrittenTo = true;
 853             }
 854             break;
 855         }
 856         else if (auto arraySubscriptExpr = dyn_cast<ArraySubscriptExpr>(parent))
 857         {
 858             if (arraySubscriptExpr->getIdx() == child)
 859                 break;
 860             walkupUp();
 861         }
 862         else if (auto operatorCallExpr = dyn_cast<CXXOperatorCallExpr>(parent))
 863         {
 864             auto callee = getCallee(operatorCallExpr);
 865             if (callee)
 866             {
 867                 // if calling a non-const operator on the var
 868                 auto calleeMethodDecl = callee->getAsCXXMethodDecl();
 869                 if (calleeMethodDecl && operatorCallExpr->getArg(0) == child)
 870                 {
 871                     if (!calleeMethodDecl->isConst())
 872                         bPotentiallyWrittenTo
 873                             = checkForWriteWhenUsingCollectionType(calleeMethodDecl);
 874                 }
 875                 else if (IsPassedByNonConst(varDecl, child, operatorCallExpr, *callee))
 876                 {
 877                     bPotentiallyWrittenTo = true;
 878                 }
 879             }
 880             else
 881                 bPotentiallyWrittenTo = true; // conservative, could improve
 882             break;
 883         }
 884         else if (auto cxxMemberCallExpr = dyn_cast<CXXMemberCallExpr>(parent))
 885         {
 886             const CXXMethodDecl* calleeMethodDecl = cxxMemberCallExpr->getMethodDecl();
 887             if (calleeMethodDecl)
 888             {
 889                 // if calling a non-const method on the var
 890                 const Expr* tmp = dyn_cast<Expr>(child);
 891                 if (tmp->isBoundMemberFunction(compiler.getASTContext()))
 892                 {
 893                     tmp = dyn_cast<MemberExpr>(tmp)->getBase();
 894                 }
 895                 if (cxxMemberCallExpr->getImplicitObjectArgument() == tmp)
 896                 {
 897                     if (!calleeMethodDecl->isConst())
 898                         bPotentiallyWrittenTo
 899                             = checkForWriteWhenUsingCollectionType(calleeMethodDecl);
 900                     break;
 901                 }
 902                 else if (IsPassedByNonConst(varDecl, child, cxxMemberCallExpr,
 903                                             CalleeWrapper(calleeMethodDecl)))
 904                     bPotentiallyWrittenTo = true;
 905             }
 906             else
 907                 bPotentiallyWrittenTo = true; // can happen in templates
 908             break;
 909         }
 910         else if (auto cxxConstructExpr = dyn_cast<CXXConstructExpr>(parent))
 911         {
 912             if (IsPassedByNonConst(varDecl, child, cxxConstructExpr,
 913                                    CalleeWrapper(cxxConstructExpr)))
 914                 bPotentiallyWrittenTo = true;
 915             break;
 916         }
 917         else if (auto callExpr = dyn_cast<CallExpr>(parent))
 918         {
 919             auto callee = getCallee(callExpr);
 920             if (callee)
 921             {
 922                 if (IsPassedByNonConst(varDecl, child, callExpr, *callee))
 923                     bPotentiallyWrittenTo = true;
 924             }
 925             else
 926                 bPotentiallyWrittenTo = true; // conservative, could improve
 927             break;
 928         }
 929         else if (auto binaryOp = dyn_cast<BinaryOperator>(parent))
 930         {
 931             BinaryOperator::Opcode op = binaryOp->getOpcode();
 932             const bool assignmentOp = op == BO_Assign || op == BO_MulAssign || op == BO_DivAssign
 933                                       || op == BO_RemAssign || op == BO_AddAssign
 934                                       || op == BO_SubAssign || op == BO_ShlAssign
 935                                       || op == BO_ShrAssign || op == BO_AndAssign
 936                                       || op == BO_XorAssign || op == BO_OrAssign;
 937             if (assignmentOp)
 938             {
 939                 if (binaryOp->getLHS() == child)
 940                     bPotentiallyWrittenTo = true;
 941                 else if (loplugin::TypeCheck(binaryOp->getLHS()->getType())
 942                              .LvalueReference()
 943                              .NonConst())
 944                     // if the LHS is a non-const reference, we could write to the var later on
 945                     bPotentiallyWrittenTo = true;
 946             }
 947             break;
 948         }
 949         else if (isa<ReturnStmt>(parent))
 950         {
 951             if (insideFunctionDecl)
 952             {
 953                 auto tc = loplugin::TypeCheck(insideFunctionDecl->getReturnType());
 954                 if (tc.LvalueReference().NonConst())
 955                     bPotentiallyWrittenTo = true;
 956             }
 957             break;
 958         }
 959         else if (isa<ConditionalOperator>(parent) || isa<SwitchStmt>(parent)
 960                  || isa<DeclStmt>(parent) || isa<WhileStmt>(parent) || isa<CXXNewExpr>(parent)
 961                  || isa<ForStmt>(parent) || isa<InitListExpr>(parent)
 962                  || isa<CXXDependentScopeMemberExpr>(parent) || isa<UnresolvedMemberExpr>(parent)
 963                  || isa<MaterializeTemporaryExpr>(parent) || isa<IfStmt>(parent)
 964                  || isa<DoStmt>(parent) || isa<CXXDeleteExpr>(parent)
 965                  || isa<UnaryExprOrTypeTraitExpr>(parent) || isa<CXXUnresolvedConstructExpr>(parent)
 966                  || isa<CompoundStmt>(parent) || isa<LabelStmt>(parent)
 967                  || isa<CXXForRangeStmt>(parent) || isa<CXXTypeidExpr>(parent)
 968                  || isa<DefaultStmt>(parent) || isa<ConstantExpr>(parent) || isa<GCCAsmStmt>(parent)
 969                  || isa<VAArgExpr>(parent) || isa<CXXDefaultArgExpr>(parent)
 970                  || isa<LambdaExpr>(parent))
 971         {
 972             break;
 973         }
 974         else
 975         {
 976             bPotentiallyWrittenTo = true;
 977             bDump = true;
 978             break;
 979         }
 980     } while (true);
 981
 982     if (bDump)
 983     {
 984         report(DiagnosticsEngine::Warning, "oh dear2, what can the matter be? writtenTo=%0",
 985                memberExpr->getBeginLoc())
 986             << bPotentiallyWrittenTo << memberExpr->getSourceRange();
 987         if (parent)
 988         {
 989             report(DiagnosticsEngine::Note, "parent over here", parent->getBeginLoc())
 990                 << parent->getSourceRange();
 991             parent->dump();
 992         }
 993         memberExpr->dump();
 994         varDecl->getType()->dump();
 995     }
 996
 997     MyVarInfo varInfo = niceName(varDecl);
 998     if (bPotentiallyWrittenTo)
 999     {
1000         writeToSet.insert(varInfo);
1001     }
1002 }
1003
1004 // return true if this not a collection type, or if it is a collection type, and we might be writing to it
1005 bool WriteOnlyVars::checkForWriteWhenUsingCollectionType(const CXXMethodDecl* calleeMethodDecl)
1006 {
1007     auto const tc = loplugin::TypeCheck(calleeMethodDecl->getParent());
1008     bool listLike = false, setLike = false, mapLike = false, cssSequence = false;
1009     if (tc.Class("deque").StdNamespace() || tc.Class("list").StdNamespace()
1010         || tc.Class("queue").StdNamespace() || tc.Class("vector").StdNamespace())
1011     {
1012         listLike = true;
1013     }
1014     else if (tc.Class("set").StdNamespace() || tc.Class("unordered_set").StdNamespace())
1015     {
1016         setLike = true;
1017     }
1018     else if (tc.Class("map").StdNamespace() || tc.Class("unordered_map").StdNamespace())
1019     {
1020         mapLike = true;
1021     }
1022     else if (tc.Class("Sequence")
1023                  .Namespace("uno")
1024                  .Namespace("star")
1025                  .Namespace("sun")
1026                  .Namespace("com")
1027                  .GlobalNamespace())
1028     {
1029         cssSequence = true;
1030     }
1031     else
1032         return true;
1033
1034     if (calleeMethodDecl->isOverloadedOperator())
1035     {
1036         auto oo = calleeMethodDecl->getOverloadedOperator();
1037         if (oo == OO_Equal)
1038             return true;
1039         // This is operator[]. We only care about things that add elements to the collection.
1040         // if nothing modifies the size of the collection, then nothing useful
1041         // is stored in it.
1042         if (listLike)
1043             return false;
1044         return true;
1045     }
1046
1047     auto name = calleeMethodDecl->getName();
1048     if (listLike || setLike || mapLike)
1049     {
1050         if (name == "reserve" || name == "shrink_to_fit" || name == "clear" || name == "erase"
1051             || name == "pop_back" || name == "pop_front" || name == "front" || name == "back"
1052             || name == "data" || name == "remove" || name == "remove_if" || name == "unique"
1053             || name == "sort" || name == "begin" || name == "end" || name == "rbegin"
1054             || name == "rend" || name == "at" || name == "find" || name == "equal_range"
1055             || name == "lower_bound" || name == "upper_bound")
1056             return false;
1057     }
1058     if (cssSequence)
1059     {
1060         if (name == "getArray" || name == "begin" || name == "end")
1061             return false;
1062     }
1063
1064     return true;
1065 }
1066
1067 bool WriteOnlyVars::IsPassedByNonConst(const VarDecl* varDecl, const Stmt* child,
1068                                        CallerWrapper callExpr, CalleeWrapper calleeFunctionDecl)
1069 {
1070     unsigned len = std::min(callExpr.getNumArgs(), calleeFunctionDecl.getNumParams());
1071     // if it's an array, passing it by value to a method typically means the
1072     // callee takes a pointer and can modify the array
1073     if (varDecl->getType()->isConstantArrayType())
1074     {
1075         for (unsigned i = 0; i < len; ++i)
1076             if (callExpr.getArg(i) == child)
1077                 if (loplugin::TypeCheck(calleeFunctionDecl.getParamType(i)).Pointer().NonConst())
1078                     return true;
1079     }
1080     else
1081     {
1082         for (unsigned i = 0; i < len; ++i)
1083             if (callExpr.getArg(i) == child)
1084                 if (loplugin::TypeCheck(calleeFunctionDecl.getParamType(i))
1085                         .LvalueReference()
1086                         .NonConst())
1087                     return true;
1088     }
1089     return false;
1090 }
1091
1092 bool WriteOnlyVars::VisitDeclRefExpr(const DeclRefExpr* declRefExpr)
1093 {
1094     const Decl* decl = declRefExpr->getDecl();
1095     const VarDecl* varDecl = dyn_cast<VarDecl>(decl);
1096     if (!varDecl)
1097         return true;
1098     if (varDecl->isImplicit() || isa<ParmVarDecl>(varDecl))
1099         return true;
1100     varDecl = varDecl->getCanonicalDecl();
1101     if (ignoreLocation(varDecl))
1102         return true;
1103     // ignore stuff that forms part of the stable URE interface
1104     if (isInUnoIncludeFile(compiler.getSourceManager().getSpellingLoc(varDecl->getLocation())))
1105         return true;
1106
1107     checkIfReadFrom(varDecl, declRefExpr);
1108
1109     checkIfWrittenTo(varDecl, declRefExpr);
1110
1111     return true;
1112 }
1113
1114 compat::optional<CalleeWrapper> WriteOnlyVars::getCallee(CallExpr const* callExpr)
1115 {
1116     FunctionDecl const* functionDecl = callExpr->getDirectCallee();
1117     if (functionDecl)
1118         return CalleeWrapper(functionDecl);
1119
1120     // Extract the functionprototype from a type
1121     clang::Type const* calleeType = callExpr->getCallee()->getType().getTypePtr();
1122     if (auto pointerType = calleeType->getUnqualifiedDesugaredType()->getAs<clang::PointerType>())
1123     {
1124         if (auto prototype = pointerType->getPointeeType()
1125                                  ->getUnqualifiedDesugaredType()
1126                                  ->getAs<FunctionProtoType>())
1127         {
1128             return CalleeWrapper(prototype);
1129         }
1130     }
1131
1132     return compat::optional<CalleeWrapper>();
1133 }
1134
1135 loplugin::Plugin::Registration<WriteOnlyVars> X("writeonlyvars", false);
1136 }
1137
1138 #endif
1139
1140 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */