compilerplugins/clang/redundantpointerops.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 <cassert>
  11 #include <string>
  12 #include <iostream>
  13 #include <fstream>
  14 #include <set>
  15
  16 #include <clang/AST/CXXInheritance.h>
  17 #include "compat.hxx"
  18 #include "plugin.hxx"
  19
  20 /**
  21  * Look for:
  22  *     (&x)->y
  23  * which can be transformed to:
  24  *      x.y
  25  * And
  26  *    &*x
  27  * which can be:
  28  *    x
  29  *
  30  * @TODO
  31  *    (*x).y
  32  *  which can be:
  33  *    x->y
  34  */
  35
  36 namespace {
  37
  38 class RedundantPointerOps:
  39     public RecursiveASTVisitor<RedundantPointerOps>, public loplugin::Plugin
  40 {
  41 public:
  42     explicit RedundantPointerOps(loplugin::InstantiationData const & data): Plugin(data) {}
  43
  44     virtual void run() override
  45     {
  46         TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
  47     }
  48
  49     bool VisitFunctionDecl(FunctionDecl const *);
  50     bool VisitMemberExpr(MemberExpr const *);
  51     bool VisitUnaryOperator(UnaryOperator const *);
  52 };
  53
  54 bool RedundantPointerOps::VisitFunctionDecl(FunctionDecl const * functionDecl)
  55 {
  56     if (ignoreLocation(functionDecl))
  57         return true;
  58     //functionDecl->dump();
  59     return true;
  60 }
  61
  62 bool RedundantPointerOps::VisitMemberExpr(MemberExpr const * memberExpr)
  63 {
  64     if (ignoreLocation(memberExpr))
  65         return true;
  66     if (memberExpr->getLocStart().isMacroID())
  67         return true;
  68     auto base = memberExpr->getBase()->IgnoreParenImpCasts();
  69             //parentStmt(parentStmt(memberExpr))->dump();
  70     if (memberExpr->isArrow())
  71     {
  72         if (auto unaryOp = dyn_cast<UnaryOperator>(base))
  73         {
  74             if (unaryOp->getOpcode() == UO_AddrOf)
  75                 report(
  76                     DiagnosticsEngine::Warning, "'&' followed by '->', rather use '.'",
  77                     memberExpr->getLocStart())
  78                     << memberExpr->getSourceRange();
  79
  80         }
  81         else if (auto operatorCallExpr = dyn_cast<CXXOperatorCallExpr>(base))
  82         {
  83             if (operatorCallExpr->getOperator() == OO_Amp)
  84                 report(
  85                     DiagnosticsEngine::Warning, "'&' followed by '->', rather use '.'",
  86                     memberExpr->getLocStart())
  87                     << memberExpr->getSourceRange();
  88
  89         }
  90     }
  91 //    else
  92 //    {
  93 //        if (auto unaryOp = dyn_cast<UnaryOperator>(base))
  94 //        {
  95 //            if (unaryOp->getOpcode() == UO_Deref)
  96 //                report(
  97 //                    DiagnosticsEngine::Warning, "'*' followed by '.', rather use '->'",
  98 //                    memberExpr->getLocStart())
  99 //                    << memberExpr->getSourceRange();
 100 //
 101 //        }
 102 //    }
 103     return true;
 104 }
 105
 106 bool RedundantPointerOps::VisitUnaryOperator(UnaryOperator const * unaryOperator)
 107 {
 108     if (ignoreLocation(unaryOperator))
 109         return true;
 110     if (unaryOperator->getLocStart().isMacroID())
 111         return true;
 112     if (unaryOperator->getOpcode() != UO_Deref)
 113         return true;
 114     auto innerOp = dyn_cast<UnaryOperator>(unaryOperator->getSubExpr()->IgnoreParenImpCasts());
 115     if (!innerOp || innerOp->getOpcode() != UO_AddrOf)
 116         return true;
 117
 118     report(
 119         DiagnosticsEngine::Warning, "'&' followed by '*', rather use '.'",
 120         unaryOperator->getLocStart())
 121         << unaryOperator->getSourceRange();
 122     return true;
 123 }
 124
 125 loplugin::Plugin::Registration< RedundantPointerOps > X("redundantpointerops");
 126
 127 }
 128
 129 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */