compilerplugins/clang/subtlezeroinit.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 #ifndef LO_CLANG_SHARED_PLUGINS
  11
  12 #include "plugin.hxx"
  13
  14 // Find occurrences of 'new T()' where the instance is zero-initialized upfront
  15 // since C++11.  For one, in many cases this may be unnecessary and unintended,
  16 // as the code was written before C++11.  For another, the zero-initialization
  17 // would go away when T gets a user-provided default constructor, for example,
  18 // so better make any necessary initialization more explicit in the code.
  19
  20 namespace {
  21
  22 class SubtleZeroInit final:
  23     public loplugin::FilteringPlugin<SubtleZeroInit>
  24 {
  25 public:
  26     explicit SubtleZeroInit(loplugin::InstantiationData const & data):
  27         FilteringPlugin(data) {}
  28
  29     bool VisitCXXNewExpr(CXXNewExpr const * expr) {
  30         if (ignoreLocation(expr)) {
  31             return true;
  32         }
  33         auto ce = expr->getConstructExpr();
  34         if (ce == nullptr) {
  35             return true;
  36         }
  37         if (!ce->requiresZeroInitialization()) {
  38             return true;
  39         }
  40         report(
  41             DiagnosticsEngine::Warning,
  42             ("if zero-initialization of %0 is intentional here, better make"
  43              " that more explicit (e.g., assigning to members, default"
  44              " constructor, default member initializers, std::memset)"),
  45             expr->getExprLoc())
  46             << ce->getType() << expr->getSourceRange();
  47         return true;
  48     }
  49
  50     virtual bool preRun() override {
  51         return compiler.getLangOpts().CPlusPlus;
  52     }
  53
  54     virtual void run() override {
  55         if (preRun()) {
  56             TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
  57         }
  58     }
  59 };
  60
  61 static loplugin::Plugin::Registration<SubtleZeroInit> subtlezeroinit("subtlezeroinit");
  62
  63 }
  64
  65 #endif // LO_CLANG_SHARED_PLUGINS
  66
  67 /* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */