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 #include <set>
  11
  12 #include "check.hxx"
  13 #include "plugin.hxx"
  14
  15 /** Look for static OUString and OUString[], they can be more efficiently declared as:
  16
  17         static const OUStringLiteral our_aLBEntryMap[] = {" ", ", "};
  18         static const OUStringLiteral sName("name");
  19
  20     which is more efficient at startup time.
  21  */
  22 namespace {
  23
  24 class StringStatic
  25     : public clang::RecursiveASTVisitor<StringStatic>
  26     , public loplugin::Plugin
  27 {
  28
  29 public:
  30     explicit StringStatic(loplugin::InstantiationData const& rData):
  31         Plugin(rData) {}
  32
  33     void run() override;
  34     bool VisitVarDecl(VarDecl const*);
  35     bool VisitReturnStmt(ReturnStmt const*);
  36 private:
  37     std::set<VarDecl const *> potentialVars;
  38     std::set<VarDecl const *> excludeVars;
  39 };
  40
  41 void StringStatic::run()
  42 {
  43     StringRef fn( compiler.getSourceManager().getFileEntryForID(
  44                       compiler.getSourceManager().getMainFileID())->getName() );
  45     // passing around pointers to global OUString
  46     if (loplugin::hasPathnamePrefix(fn, SRCDIR "/filter/source/svg/"))
  47          return;
  48     // has a mix of literals and refs to external OUStrings
  49     if (loplugin::isSamePathname(fn, SRCDIR "/ucb/source/ucp/webdav-neon/ContentProperties.cxx"))
  50          return;
  51
  52     TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
  53
  54     for (auto const & pVarDecl : excludeVars) {
  55         potentialVars.erase(pVarDecl);
  56     }
  57     for (auto const & varDecl : potentialVars) {
  58         report(DiagnosticsEngine::Warning,
  59                 "rather declare this using OUStringLiteral or char[]",
  60                 varDecl->getLocation())
  61             << varDecl->getSourceRange();
  62     }
  63 }
  64
  65 bool StringStatic::VisitVarDecl(VarDecl const* varDecl)
  66 {
  67     if (ignoreLocation(varDecl)) {
  68         return true;
  69     }
  70     QualType qt = varDecl->getType();
  71     if (!varDecl->hasGlobalStorage()
  72         || !varDecl->isThisDeclarationADefinition()
  73         || !qt.isConstQualified()) {
  74         return true;
  75     }
  76     if (qt->isArrayType()) {
  77         qt = qt->getAsArrayTypeUnsafe()->getElementType();
  78     }
  79     if (!loplugin::TypeCheck(qt).Class("OUString").Namespace("rtl").GlobalNamespace()) {
  80         return true;
  81     }
  82     if (varDecl->hasInit()) {
  83         Expr const * expr = varDecl->getInit();
  84         while (true) {
  85             if (ExprWithCleanups const * exprWithCleanups = dyn_cast<ExprWithCleanups>(expr)) {
  86                 expr = exprWithCleanups->getSubExpr();
  87             }
  88             else if (CastExpr const * castExpr = dyn_cast<CastExpr>(expr)) {
  89                 expr = castExpr->getSubExpr();
  90             }
  91             else if (MaterializeTemporaryExpr const * materializeExpr = dyn_cast<MaterializeTemporaryExpr>(expr)) {
  92                 expr = materializeExpr->GetTemporaryExpr();
  93             }
  94             else if (CXXBindTemporaryExpr const * bindExpr = dyn_cast<CXXBindTemporaryExpr>(expr)) {
  95                 expr = bindExpr->getSubExpr();
  96             }
  97             else if (CXXConstructExpr const * constructExpr = dyn_cast<CXXConstructExpr>(expr)) {
  98                 if (constructExpr->getNumArgs() != 1) {
  99                     return true;
 100                 }
 101                 expr = constructExpr->getArg(0);
 102             } else if (isa<CallExpr>(expr)) {
 103                 return true;
 104             } else {
 105                 break;
 106             }
 107         }
 108     }
 109     potentialVars.insert(varDecl);
 110
 111     return true;
 112 }
 113
 114 bool StringStatic::VisitReturnStmt(ReturnStmt const * returnStmt)
 115 {
 116     if (ignoreLocation(returnStmt)) {
 117         return true;
 118     }
 119     if (!returnStmt->getRetValue()) {
 120         return true;
 121     }
 122     DeclRefExpr const * declRef = dyn_cast<DeclRefExpr>(returnStmt->getRetValue());
 123     if (!declRef) {
 124         return true;
 125     }
 126     VarDecl const * varDecl = dyn_cast<VarDecl>(declRef->getDecl());
 127     if (varDecl) {
 128         excludeVars.insert(varDecl);
 129     }
 130     return true;
 131 }
 132
 133 loplugin::Plugin::Registration<StringStatic> X("stringstatic");
 134
 135 } // namespace
 136
 137 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */