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 <set>
  13
  14 #include "check.hxx"
  15 #include "plugin.hxx"
  16
  17 /** Look for static OUString and OUString[], they can be more efficiently declared as:
  18
  19         static const OUStringLiteral our_aLBEntryMap[] = {" ", ", "};
  20         static const OUStringLiteral sName("name");
  21
  22     which is more efficient at startup time.
  23  */
  24 namespace {
  25
  26 class StringStatic
  27     : public loplugin::FilteringPlugin<StringStatic>
  28 {
  29
  30 public:
  31     explicit StringStatic(loplugin::InstantiationData const& rData):
  32         FilteringPlugin(rData) {}
  33
  34     void run() override;
  35     bool preRun() override;
  36     void postRun() override;
  37     bool VisitVarDecl(VarDecl const*);
  38     bool VisitReturnStmt(ReturnStmt const*);
  39 private:
  40     std::set<VarDecl const *> potentialVars;
  41     std::set<VarDecl const *> excludeVars;
  42 };
  43
  44 void StringStatic::run()
  45 {
  46     if( preRun())
  47         if( TraverseDecl(compiler.getASTContext().getTranslationUnitDecl()))
  48             postRun();
  49 }
  50
  51 bool StringStatic::preRun()
  52 {
  53     StringRef fn(handler.getMainFileName());
  54     // passing around pointers to global OUString
  55     if (loplugin::hasPathnamePrefix(fn, SRCDIR "/filter/source/svg/"))
  56          return false;
  57     // has a mix of literals and refs to external OUStrings
  58     if (loplugin::isSamePathname(fn, SRCDIR "/ucb/source/ucp/webdav-neon/ContentProperties.cxx"))
  59          return false;
  60     return true;
  61 }
  62
  63 void StringStatic::postRun()
  64 {
  65     for (auto const & pVarDecl : excludeVars) {
  66         potentialVars.erase(pVarDecl);
  67     }
  68     for (auto const & varDecl : potentialVars) {
  69         report(DiagnosticsEngine::Warning,
  70                 "rather declare this using OUStringLiteral or char[]",
  71                 varDecl->getLocation())
  72             << varDecl->getSourceRange();
  73     }
  74 }
  75
  76 bool StringStatic::VisitVarDecl(VarDecl const* varDecl)
  77 {
  78     if (ignoreLocation(varDecl)) {
  79         return true;
  80     }
  81     QualType qt = varDecl->getType();
  82     if (!varDecl->hasGlobalStorage()
  83         || !varDecl->isThisDeclarationADefinition()
  84         || !qt.isConstQualified()) {
  85         return true;
  86     }
  87     if (qt->isArrayType()) {
  88         qt = qt->getAsArrayTypeUnsafe()->getElementType();
  89     }
  90     if (!loplugin::TypeCheck(qt).Class("OUString").Namespace("rtl").GlobalNamespace()) {
  91         return true;
  92     }
  93     if (varDecl->hasInit()) {
  94         Expr const * expr = varDecl->getInit();
  95         while (true) {
  96             if (ExprWithCleanups const * exprWithCleanups = dyn_cast<ExprWithCleanups>(expr)) {
  97                 expr = exprWithCleanups->getSubExpr();
  98             }
  99             else if (CastExpr const * castExpr = dyn_cast<CastExpr>(expr)) {
 100                 expr = castExpr->getSubExpr();
 101             }
 102             else if (MaterializeTemporaryExpr const * materializeExpr = dyn_cast<MaterializeTemporaryExpr>(expr)) {
 103                 expr = materializeExpr->GetTemporaryExpr();
 104             }
 105             else if (CXXBindTemporaryExpr const * bindExpr = dyn_cast<CXXBindTemporaryExpr>(expr)) {
 106                 expr = bindExpr->getSubExpr();
 107             }
 108             else if (CXXConstructExpr const * constructExpr = dyn_cast<CXXConstructExpr>(expr)) {
 109                 if (constructExpr->getNumArgs() != 1) {
 110                     return true;
 111                 }
 112                 expr = constructExpr->getArg(0);
 113             } else if (isa<CallExpr>(expr)) {
 114                 return true;
 115             } else {
 116                 break;
 117             }
 118         }
 119     }
 120     potentialVars.insert(varDecl);
 121
 122     return true;
 123 }
 124
 125 bool StringStatic::VisitReturnStmt(ReturnStmt const * returnStmt)
 126 {
 127     if (ignoreLocation(returnStmt)) {
 128         return true;
 129     }
 130     if (!returnStmt->getRetValue()) {
 131         return true;
 132     }
 133     DeclRefExpr const * declRef = dyn_cast<DeclRefExpr>(returnStmt->getRetValue());
 134     if (!declRef) {
 135         return true;
 136     }
 137     VarDecl const * varDecl = dyn_cast<VarDecl>(declRef->getDecl());
 138     if (varDecl) {
 139         excludeVars.insert(varDecl);
 140     }
 141     return true;
 142 }
 143
 144 loplugin::Plugin::Registration<StringStatic> stringstatic("stringstatic");
 145
 146 } // namespace
 147
 148 #endif // LO_CLANG_SHARED_PLUGINS
 149
 150 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */