compilerplugins/clang/stringconcatliterals.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 "plugin.hxx"
  13 #include "check.hxx"
  14
  15 namespace {
  16
  17 Expr const * stripCtor(Expr const * expr) {
  18     auto e1 = expr;
  19     if (auto const e = dyn_cast<CXXFunctionalCastExpr>(e1)) {
  20         e1 = e->getSubExpr()->IgnoreParenImpCasts();
  21     }
  22     if (auto const e = dyn_cast<CXXBindTemporaryExpr>(e1)) {
  23         e1 = e->getSubExpr()->IgnoreParenImpCasts();
  24     }
  25     auto const e2 = dyn_cast<CXXConstructExpr>(e1);
  26     if (e2 == nullptr) {
  27         return expr;
  28     }
  29     auto qt = loplugin::DeclCheck(e2->getConstructor());
  30     if (qt.MemberFunction().Struct("OStringLiteral").Namespace("rtl").GlobalNamespace()) {
  31         if (e2->getNumArgs() == 1) {
  32             return e2->getArg(0)->IgnoreParenImpCasts();
  33         }
  34         return expr;
  35     }
  36     if (!((qt.MemberFunction().Class("OString").Namespace("rtl")
  37            .GlobalNamespace())
  38           || (qt.MemberFunction().Class("OUString").Namespace("rtl")
  39               .GlobalNamespace())
  40           || qt.MemberFunction().Struct("OUStringLiteral").Namespace("rtl").GlobalNamespace()))
  41     {
  42         return expr;
  43     }
  44     if (e2->getNumArgs() != 2) {
  45         return expr;
  46     }
  47     return e2->getArg(0)->IgnoreParenImpCasts();
  48 }
  49
  50 class StringConcatLiterals:
  51     public loplugin::FilteringPlugin<StringConcatLiterals>
  52 {
  53 public:
  54     explicit StringConcatLiterals(loplugin::InstantiationData const & data):
  55         FilteringPlugin(data) {}
  56
  57     void run() override
  58     { TraverseDecl(compiler.getASTContext().getTranslationUnitDecl()); }
  59
  60     bool VisitCallExpr(CallExpr const * expr);
  61
  62 private:
  63     bool isStringLiteral(Expr const * expr);
  64 };
  65
  66 bool StringConcatLiterals::VisitCallExpr(CallExpr const * expr) {
  67     if (ignoreLocation(expr)) {
  68         return true;
  69     }
  70     FunctionDecl const * fdecl = expr->getDirectCallee();
  71     if (fdecl == nullptr) {
  72         return true;
  73     }
  74     OverloadedOperatorKind oo = fdecl->getOverloadedOperator();
  75     if ((oo != OverloadedOperatorKind::OO_Plus
  76          && oo != OverloadedOperatorKind::OO_LessLess)
  77         || fdecl->getNumParams() != 2 || expr->getNumArgs() != 2
  78         || !isStringLiteral(expr->getArg(1)->IgnoreParenImpCasts()))
  79     {
  80         return true;
  81     }
  82     SourceLocation leftLoc;
  83     auto const leftExpr = expr->getArg(0)->IgnoreParenImpCasts();
  84     if (isStringLiteral(leftExpr)) {
  85         leftLoc = compat::getBeginLoc(leftExpr);
  86     } else {
  87         CallExpr const * left = dyn_cast<CallExpr>(leftExpr);
  88         if (left == nullptr) {
  89             return true;
  90         }
  91         FunctionDecl const * ldecl = left->getDirectCallee();
  92         if (ldecl == nullptr) {
  93             return true;
  94         }
  95         OverloadedOperatorKind loo = ldecl->getOverloadedOperator();
  96         if ((loo != OverloadedOperatorKind::OO_Plus
  97              && loo != OverloadedOperatorKind::OO_LessLess)
  98             || ldecl->getNumParams() != 2 || left->getNumArgs() != 2
  99             || !isStringLiteral(left->getArg(1)->IgnoreParenImpCasts()))
 100         {
 101             return true;
 102         }
 103         leftLoc = compat::getBeginLoc(left->getArg(1));
 104     }
 105
 106     // We add an extra " " in the TOOLS_WARN_EXCEPTION macro, which triggers this plugin
 107     if (loplugin::isSamePathname(
 108             getFilenameOfLocation(
 109                 compiler.getSourceManager().getSpellingLoc(
 110                     compiler.getSourceManager().getImmediateMacroCallerLoc(
 111                         compiler.getSourceManager().getImmediateMacroCallerLoc(
 112                             compat::getBeginLoc(expr))))),
 113             SRCDIR "/include/tools/diagnose_ex.h"))
 114         return true;
 115
 116     StringRef name {
 117         getFilenameOfLocation(
 118             compiler.getSourceManager().getSpellingLoc(compat::getBeginLoc(expr))) };
 119     if (loplugin::isSamePathname(
 120             name, SRCDIR "/sal/qa/rtl/oustringbuffer/test_oustringbuffer_assign.cxx")
 121         || loplugin::isSamePathname(
 122             name, SRCDIR "/sal/qa/rtl/strings/test_ostring_concat.cxx")
 123         || loplugin::isSamePathname(
 124             name, SRCDIR "/sal/qa/rtl/strings/test_oustring_concat.cxx"))
 125     {
 126         return true;
 127     }
 128     CXXOperatorCallExpr const * op = dyn_cast<CXXOperatorCallExpr>(expr);
 129     report(
 130         DiagnosticsEngine::Warning,
 131         "replace '%0' between string literals with juxtaposition",
 132         op == nullptr ? expr->getExprLoc() : op->getOperatorLoc())
 133         << (oo == OverloadedOperatorKind::OO_Plus ? "+" : "<<")
 134         << SourceRange(leftLoc, compat::getEndLoc(expr->getArg(1)));
 135     return true;
 136 }
 137
 138 bool StringConcatLiterals::isStringLiteral(Expr const * expr) {
 139     expr = stripCtor(expr);
 140     if (!isa<clang::StringLiteral>(expr)) {
 141         return false;
 142     }
 143     // OSL_THIS_FUNC may be defined as "" in include/osl/diagnose.h, so don't
 144     // warn about expressions like 'SAL_INFO(..., OSL_THIS_FUNC << ":")' or
 145     // 'OUString(OSL_THIS_FUNC) + ":"':
 146     auto loc = compat::getBeginLoc(expr);
 147     while (compiler.getSourceManager().isMacroArgExpansion(loc)) {
 148         loc = compiler.getSourceManager().getImmediateMacroCallerLoc(loc);
 149     }
 150     return !compiler.getSourceManager().isMacroBodyExpansion(loc)
 151         || (Lexer::getImmediateMacroName(
 152                 loc, compiler.getSourceManager(), compiler.getLangOpts())
 153             != "OSL_THIS_FUNC");
 154 }
 155
 156 loplugin::Plugin::Registration<StringConcatLiterals> stringconcatliterals("stringconcatliterals");
 157
 158 } // namespace
 159
 160 #endif // LO_CLANG_SHARED_PLUGINS
 161
 162 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */