compilerplugins/clang/store/returnunique.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 // Find places where a std::unique_ptr is release()'ed and returned as a raw
  11 // pointer.  Some occurrences of that might better be rewritten to return the
  12 // unique_ptr is returned directly.  (But other occurrences might be fine the
  13 // way they are, hence place this plugin into store/).
  14
  15 #include <memory>
  16 #include "plugin.hxx"
  17
  18 namespace {
  19
  20 class ReturnUnique:
  21     public loplugin::FilteringPlugin<ReturnUnique>
  22 {
  23 public:
  24     explicit ReturnUnique(InstantiationData const & data): FilteringPlugin(data) {}
  25
  26     void run() override {
  27         if (compiler.getLangOpts().CPlusPlus) {
  28             TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
  29         }
  30     }
  31
  32     bool VisitReturnStmt(ReturnStmt const * stmt);
  33 };
  34
  35 bool ReturnUnique::VisitReturnStmt(ReturnStmt const * stmt) {
  36     if (ignoreLocation(stmt)) {
  37         return true;
  38     }
  39     auto const e1 = stmt->getRetValue();
  40     if (e1 == nullptr) {
  41         return true;
  42     }
  43     auto const e2 = dyn_cast<CXXMemberCallExpr>(e1->IgnoreParenImpCasts());
  44     if (e2 == nullptr) {
  45         return true;
  46     }
  47     auto const d1 = e2->getMethodDecl();
  48     if (d1 == nullptr) { // call via ptr to member
  49         return true;
  50     }
  51     auto const d2 = d1->getParent();
  52     assert(d2 != nullptr);
  53     assert(d2->getParent() != nullptr);
  54     auto const d3 = dyn_cast<NamespaceDecl>(d2->getParent());
  55     if (d3 == nullptr
  56         /* || dyn_cast<TranslationUnitDecl>(d3->getParent()) == nullptr */)
  57     {
  58         return true;
  59     }
  60     auto const id3 = d3->getIdentifier();
  61     if (id3 == nullptr /* || id3->getName() != "std" */) {
  62         return true;
  63     }
  64     auto const id2 = d2->getIdentifier();
  65     if (id2 == nullptr || id2->getName() != "unique_ptr") {
  66         return true;
  67     }
  68     auto const id1 = d1->getIdentifier();
  69     if (id1 == nullptr || id1->getName() != "release") {
  70         return true;
  71     }
  72     report(
  73         DiagnosticsEngine::Warning, "return std::unique_ptr::release",
  74         e2->getLocStart())
  75         << stmt->getSourceRange();
  76     return true;
  77 }
  78
  79 loplugin::Plugin::Registration<ReturnUnique> X("returnunique");
  80
  81 }
  82
  83 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */