compilerplugins/clang/stringstatic.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 #ifndef LO_CLANG_SHARED_PLUGINS
  11
  12 #include "check.hxx"
  13 #include "compat.hxx"
  14 #include "plugin.hxx"
  15
  16 #include <unordered_set>
  17
  18 /** Look for static O*String and O*String[], they can be more efficiently declared as:
  19
  20         static constexpr OUStringLiteral our_aLBEntryMap[] = {u" ", u", "};
  21         static constexpr OUStringLiteral sName(u"name");
  22
  23     which is more efficient at startup time.
  24  */
  25 namespace {
  26
  27 class StringStatic
  28     : public loplugin::FilteringPlugin<StringStatic>
  29 {
  30
  31 public:
  32     explicit StringStatic(loplugin::InstantiationData const& rData):
  33         FilteringPlugin(rData) {}
  34
  35     void run() override;
  36     bool preRun() override;
  37     void postRun() override;
  38     bool VisitVarDecl(VarDecl const*);
  39     bool VisitReturnStmt(ReturnStmt const*);
  40     bool VisitDeclRefExpr(DeclRefExpr const*);
  41     bool VisitMemberExpr(MemberExpr const*);
  42
  43 private:
  44     std::unordered_set<VarDecl const *> potentialVars;
  45     std::unordered_set<VarDecl const *> excludeVars;
  46 };
  47
  48 void StringStatic::run()
  49 {
  50     if( preRun())
  51         if( TraverseDecl(compiler.getASTContext().getTranslationUnitDecl()))
  52             postRun();
  53 }
  54
  55 bool StringStatic::preRun()
  56 {
  57     StringRef fn(handler.getMainFileName());
  58     // passing around pointers to global OUString
  59     if (loplugin::hasPathnamePrefix(fn, SRCDIR "/filter/source/svg/"))
  60          return false;
  61     // has a mix of literals and refs to external OUStrings
  62     if (loplugin::isSamePathname(fn, SRCDIR "/ucb/source/ucp/webdav-neon/ContentProperties.cxx"))
  63          return false;
  64     return true;
  65 }
  66
  67 void StringStatic::postRun()
  68 {
  69     for (auto const & pVarDecl : excludeVars) {
  70         potentialVars.erase(pVarDecl);
  71     }
  72     for (auto const & varDecl : potentialVars) {
  73         report(DiagnosticsEngine::Warning,
  74                 "rather declare this using OUStringLiteral/OStringLiteral/char[]",
  75                 varDecl->getLocation())
  76             << varDecl->getSourceRange();
  77     }
  78 }
  79
  80 bool StringStatic::VisitVarDecl(VarDecl const* varDecl)
  81 {
  82     if (ignoreLocation(varDecl))
  83         return true;
  84     QualType qt = varDecl->getType();
  85     if (!varDecl->hasGlobalStorage())
  86         return true;
  87     if (varDecl->hasGlobalStorage() && !varDecl->isStaticLocal()) {
  88         //TODO: For a non-public static member variable from an included file, we could still
  89         // examine it further if all its uses must be seen in that included file:
  90         if (!compiler.getSourceManager().isInMainFile(varDecl->getLocation())) {
  91             return true;
  92         }
  93     }
  94     if (!varDecl->isThisDeclarationADefinition()
  95         || !qt.isConstQualified())
  96         return true;
  97     if (qt->isArrayType())
  98         qt = qt->getAsArrayTypeUnsafe()->getElementType();
  99
 100     auto tc = loplugin::TypeCheck(qt);
 101     if (!tc.Class("OUString").Namespace("rtl").GlobalNamespace()
 102         && !tc.Class("OString").Namespace("rtl").GlobalNamespace())
 103         return true;
 104     if (varDecl->hasInit())
 105     {
 106         Expr const * expr = varDecl->getInit();
 107         while (true) {
 108             if (ExprWithCleanups const * exprWithCleanups = dyn_cast<ExprWithCleanups>(expr)) {
 109                 expr = exprWithCleanups->getSubExpr();
 110             }
 111             else if (CastExpr const * castExpr = dyn_cast<CastExpr>(expr)) {
 112                 expr = castExpr->getSubExpr();
 113             }
 114             else if (MaterializeTemporaryExpr const * materializeExpr = dyn_cast<MaterializeTemporaryExpr>(expr)) {
 115                 expr = compat::getSubExpr(materializeExpr);
 116             }
 117             else if (CXXBindTemporaryExpr const * bindExpr = dyn_cast<CXXBindTemporaryExpr>(expr)) {
 118                 expr = bindExpr->getSubExpr();
 119             }
 120             else if (CXXConstructExpr const * constructExpr = dyn_cast<CXXConstructExpr>(expr)) {
 121                 if (constructExpr->getNumArgs() == 0) {
 122                     return true;
 123                 }
 124                 expr = constructExpr->getArg(0);
 125             } else if (isa<CallExpr>(expr)) {
 126                 return true;
 127             } else {
 128                 break;
 129             }
 130         }
 131     }
 132     potentialVars.insert(varDecl);
 133
 134     return true;
 135 }
 136
 137 bool StringStatic::VisitReturnStmt(ReturnStmt const * returnStmt)
 138 {
 139     if (ignoreLocation(returnStmt)) {
 140         return true;
 141     }
 142     if (!returnStmt->getRetValue()) {
 143         return true;
 144     }
 145     DeclRefExpr const * declRef = dyn_cast<DeclRefExpr>(returnStmt->getRetValue());
 146     if (!declRef) {
 147         return true;
 148     }
 149     VarDecl const * varDecl = dyn_cast<VarDecl>(declRef->getDecl());
 150     if (varDecl) {
 151         excludeVars.insert(varDecl);
 152     }
 153     return true;
 154 }
 155
 156 bool StringStatic::VisitDeclRefExpr(DeclRefExpr const * declRef)
 157 {
 158     if (ignoreLocation(declRef))
 159         return true;
 160     VarDecl const * varDecl = dyn_cast<VarDecl>(declRef->getDecl());
 161     if (!varDecl)
 162         return true;
 163     if (potentialVars.count(varDecl) == 0)
 164         return true;
 165     // ignore globals that are used in CPPUNIT_ASSERT expressions, otherwise we can end up
 166     // trying to compare an OUStringLiteral and an OUString, and CPPUNIT can't handle that
 167     auto loc = compat::getBeginLoc(declRef);
 168     if (compiler.getSourceManager().isMacroArgExpansion(loc))
 169     {
 170         StringRef name { Lexer::getImmediateMacroName(loc, compiler.getSourceManager(), compiler.getLangOpts()) };
 171         if (name.startswith("CPPUNIT_ASSERT"))
 172             excludeVars.insert(varDecl);
 173     }
 174     return true;
 175 }
 176
 177 bool StringStatic::VisitMemberExpr(MemberExpr const * expr)
 178 {
 179     if (ignoreLocation(expr))
 180         return true;
 181     auto const declRef = dyn_cast<DeclRefExpr>(expr->getBase());
 182     if (declRef == nullptr) {
 183         return true;
 184     }
 185     VarDecl const * varDecl = dyn_cast<VarDecl>(declRef->getDecl());
 186     if (!varDecl)
 187         return true;
 188     if (potentialVars.count(varDecl) == 0)
 189         return true;
 190     auto const id = expr->getMemberDecl()->getIdentifier();
 191     if (id == nullptr || id->getName() != "pData") {
 192         return true;
 193     }
 194     excludeVars.insert(varDecl);
 195     return true;
 196 }
 197
 198 loplugin::Plugin::Registration<StringStatic> stringstatic("stringstatic");
 199
 200 } // namespace
 201
 202 #endif // LO_CLANG_SHARED_PLUGINS
 203
 204 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */