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