compilerplugins/clang/externandnotdefined.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 #include <string>
  11
  12 #include "plugin.hxx"
  13
  14 // Having an extern prototype for a method in a module and not actually declaring that method is dodgy.
  15 //
  16
  17 namespace {
  18
  19 class ExternAndNotDefined:
  20     public RecursiveASTVisitor<ExternAndNotDefined>, public loplugin::Plugin
  21 {
  22 public:
  23     explicit ExternAndNotDefined(loplugin::InstantiationData const & data): Plugin(data) {}
  24
  25     virtual void run() override { TraverseDecl(compiler.getASTContext().getTranslationUnitDecl()); }
  26
  27     bool VisitFunctionDecl(const FunctionDecl * decl);
  28 };
  29
  30 bool ExternAndNotDefined::VisitFunctionDecl(const FunctionDecl * functionDecl) {
  31     if (ignoreLocation(functionDecl)) {
  32         return true;
  33     }
  34     if (functionDecl->isDefined() || functionDecl->isPure()
  35       || (functionDecl->getLinkageAndVisibility().getLinkage()
  36           != ExternalLinkage)) {
  37         return true;
  38     }
  39     //TODO, filtering out anything template for now:
  40     if (functionDecl->isDependentContext()) {
  41         return true;
  42     }
  43     CXXRecordDecl const * r = dyn_cast<CXXRecordDecl>(functionDecl->getDeclContext());
  44     if (r != nullptr && r->getTemplateSpecializationKind() != TSK_Undeclared) {
  45         return true;
  46     }
  47     // this is the bison/flex C API, it has to be defined this way
  48     std::string functionName = functionDecl->getNameAsString();
  49     if (functionName == "yyerror" || functionName == "YYWarning" || functionName == "yyparse" || functionName == "yylex") {
  50         return true;
  51     }
  52     // see vcl/unx/gtk/app/gtksys.cxx, typename conflicts prevent using the right include
  53     if (functionName == "gdk_x11_screen_get_screen_number") {
  54         return true;
  55     }
  56     if (!compiler.getSourceManager().isInMainFile(functionDecl->getLocation()))
  57     {
  58         return true;
  59     }
  60     StringRef fileName { compiler.getSourceManager().getFilename(functionDecl->getLocation()) };
  61     // the filters use some kind of dynamic loading stunt
  62     if (loplugin::hasPathnamePrefix(fileName, SRCDIR "/filter/qa/")) {
  63         return true;
  64     }
  65     report(
  66         DiagnosticsEngine::Warning,
  67         "extern prototype in main file without definition",
  68         functionDecl->getLocation())
  69       << functionDecl->getSourceRange();
  70     return true;
  71 }
  72
  73
  74 loplugin::Plugin::Registration< ExternAndNotDefined > X("externandnotdefined");
  75
  76 }
  77
  78 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */