compilerplugins/clang/charrightshift.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
   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 "check.hxx"
  11 #include "plugin.hxx"
  12
  13 namespace {
  14
  15 class CharRightShift:
  16     public RecursiveASTVisitor<CharRightShift>, public loplugin::Plugin
  17 {
  18 public:
  19     explicit CharRightShift(loplugin::InstantiationData const & data):
  20         Plugin(data) {}
  21
  22     void run() override
  23     { TraverseDecl(compiler.getASTContext().getTranslationUnitDecl()); }
  24
  25     bool VisitBinShr(BinaryOperator const * expr) {
  26         if (ignoreLocation(expr)) {
  27             return true;
  28         }
  29         auto t = expr->getLHS()->IgnoreParenImpCasts()->getType();
  30         if (!loplugin::TypeCheck(t).Char()) {
  31             return true;
  32         }
  33         if (!expr->getRHS()->getType()->isBuiltinType()) {
  34             //TODO: in which case the expression should be an
  35             // CXXOperatorCallExpr instead of a BinaryOperator? but at least
  36             // recent Clang trunk reports
  37             //
  38             //  '(' >> orExpression
  39             //
  40             // (connectivity/source/commontools/RowFunctionParser.cxx, the RHS
  41             // being of type boost::spirit::rule<ScannerT>) here
  42             return true;
  43         }
  44         report(
  45             DiagnosticsEngine::Warning,
  46             ("right shift of %0 is implementation-defined when 'char' is signed"
  47              " and value is negative"),
  48             expr->getLHS()->getExprLoc())
  49             << t << expr->getSourceRange();
  50         return true;
  51     }
  52 };
  53
  54 loplugin::Plugin::Registration<CharRightShift> X("charrightshift");
  55
  56 }
  57
  58 /* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */