compilerplugins/clang/data.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 #ifndef LO_CLANG_SHARED_PLUGINS
  10
  11 #include "check.hxx"
  12 #include "compat.hxx"
  13 #include "plugin.hxx"
  14
  15 // For std::array or std::vector x, replace &x[0] with x.data().
  16
  17 namespace
  18 {
  19 class Data final : public loplugin::FilteringPlugin<Data>
  20 {
  21 public:
  22     explicit Data(loplugin::InstantiationData const& data)
  23         : FilteringPlugin(data)
  24     {
  25     }
  26
  27     bool VisitUnaryOperator(UnaryOperator const* expr)
  28     {
  29         if (ignoreLocation(expr))
  30         {
  31             return true;
  32         }
  33         if (expr->getOpcode() != UO_AddrOf)
  34         {
  35             return true;
  36         }
  37         auto const e1 = dyn_cast<CXXOperatorCallExpr>(expr->getSubExpr()->IgnoreParenImpCasts());
  38         if (e1 == nullptr)
  39         {
  40             return true;
  41         }
  42         if (e1->getOperator() != OO_Subscript)
  43         {
  44             return true;
  45         }
  46         auto const t = e1->getArg(0)->getType();
  47         auto const chk = loplugin::TypeCheck(t);
  48         if (!(chk.Class("array").StdNamespace() || chk.Class("vector").StdNamespace()))
  49         {
  50             return true;
  51         }
  52         auto const e2 = e1->getArg(1);
  53         if (e2->isValueDependent())
  54         {
  55             return true;
  56         }
  57         APSInt v;
  58         if (!compat::EvaluateAsInt(e2, v, compiler.getASTContext()))
  59         {
  60             return true;
  61         }
  62         if (v != 0)
  63         {
  64             return true;
  65         }
  66         report(DiagnosticsEngine::Warning,
  67                "use 'data' member function to access first element of %0", expr->getExprLoc())
  68             << t << expr->getSourceRange();
  69         return true;
  70     }
  71
  72     bool preRun() override { return compiler.getLangOpts().CPlusPlus; }
  73
  74     void run() override
  75     {
  76         if (preRun())
  77         {
  78             TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
  79         }
  80     }
  81 };
  82
  83 static loplugin::Plugin::Registration<Data> data("data");
  84
  85 } // namespace
  86
  87 #endif // LO_CLANG_SHARED_PLUGINS
  88
  89 /* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */