compilerplugins/clang/constmove.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 // Find occurrences of std::move on const-qualified types.  While there might theoretically be
  11 // legitimate uses for such (for which this plugin would generate false positives and would need to
  12 // be updated), in practice they tend to point at suspicious code that should be cleaned up in some
  13 // way.
  14
  15 #ifndef LO_CLANG_SHARED_PLUGINS
  16
  17 #include "check.hxx"
  18 #include "plugin.hxx"
  19
  20 namespace
  21 {
  22 class ConstMove final : public loplugin::FilteringPlugin<ConstMove>
  23 {
  24 public:
  25     explicit ConstMove(loplugin::InstantiationData const& data)
  26         : FilteringPlugin(data)
  27     {
  28     }
  29
  30     bool preRun() override { return compiler.getLangOpts().CPlusPlus; }
  31
  32     void run() override
  33     {
  34         if (preRun())
  35         {
  36             TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
  37         }
  38     }
  39
  40     bool VisitCallExpr(CallExpr const* expr)
  41     {
  42         if (ignoreLocation(expr))
  43         {
  44             return true;
  45         }
  46         auto const t = expr->getType();
  47         if (!t.isConstQualified())
  48         {
  49             return true;
  50         }
  51         auto const d = expr->getDirectCallee();
  52         if (d == nullptr)
  53         {
  54             return true;
  55         }
  56         if (!loplugin::DeclCheck(d).Function("move").StdNamespace())
  57         {
  58             return true;
  59         }
  60         switch (expr->getNumArgs())
  61         {
  62             case 0:
  63                 return true;
  64             case 1:
  65                 break;
  66             default:
  67                 if (!isa<CXXDefaultArgExpr>(expr->getArg(1)))
  68                 {
  69                     return true;
  70                 }
  71                 break;
  72         }
  73         report(DiagnosticsEngine::Warning, "suspicious 'std::move' from %0 to const-qualified %1",
  74                expr->getExprLoc())
  75             << expr->getArg(0)->IgnoreImplicit()->getType() << t << expr->getSourceRange();
  76         return true;
  77     }
  78 };
  79
  80 static loplugin::Plugin::Registration<ConstMove> constmove("constmove");
  81 }
  82
  83 #endif
  84
  85 /* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */