compilerplugins/clang/staticaccess.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 <cassert>
  11
  12 #include "plugin.hxx"
  13
  14 namespace {
  15
  16 bool isStatic(ValueDecl const * decl, bool * memberEnumerator) {
  17     assert(memberEnumerator != nullptr);
  18     // clang::MemberExpr::getMemberDecl is documented to return either a
  19     // FieldDecl or a CXXMethodDecl, but can apparently also return a VarDecl
  20     // (as C++ static data members are modeled by VarDecl, not FieldDecl) or an
  21     // EnumConstantDecl (struct { enum {E}; } s; s.E;), see
  22     // <https://reviews.llvm.org/D23907> "Fix documentation of
  23     // MemberExpr::getMemberDecl":
  24     auto fd = dyn_cast<FieldDecl>(decl);
  25     if (fd != nullptr) {
  26         *memberEnumerator = false;
  27         return false;
  28     }
  29     auto vd = dyn_cast<VarDecl>(decl);
  30     if (vd != nullptr) {
  31         *memberEnumerator = false;
  32         assert(vd->isStaticDataMember());
  33         return true;
  34     }
  35     auto md = dyn_cast<CXXMethodDecl>(decl);
  36     if (md != nullptr) {
  37         *memberEnumerator = false;
  38         return md->isStatic();
  39     }
  40     assert(dyn_cast<EnumConstantDecl>(decl) != nullptr);
  41     *memberEnumerator = true;
  42     return true;
  43 }
  44
  45 class StaticAccess:
  46     public loplugin::FilteringPlugin<StaticAccess>
  47 {
  48 public:
  49     explicit StaticAccess(loplugin::InstantiationData const & data):
  50         FilteringPlugin(data) {}
  51
  52     void run() override
  53     { TraverseDecl(compiler.getASTContext().getTranslationUnitDecl()); }
  54
  55     bool VisitMemberExpr(MemberExpr const * expr);
  56 };
  57
  58 bool StaticAccess::VisitMemberExpr(MemberExpr const * expr) {
  59     if (ignoreLocation(expr)) {
  60         return true;
  61     }
  62     auto decl = expr->getMemberDecl();
  63     bool me;
  64     if (!isStatic(decl, &me)) {
  65         return true;
  66     }
  67     auto const loc = expr->getExprLoc();
  68     if (compiler.getSourceManager().isMacroBodyExpansion(loc)) {
  69         auto const name = Lexer::getImmediateMacroName(
  70             loc, compiler.getSourceManager(), compiler.getLangOpts());
  71         if (name == "BEGIN_COM_MAP" || name == "DEFAULT_REFLECTION_HANDLER") {
  72             // .../VC/Tools/MSVC/14.14.26428/atlmfc/include\atlcom.h(2226,10):  note: expanded from
  73             //   macro 'BEGIN_COM_MAP'
  74             //     return this->InternalQueryInterface(this, _GetEntries(), iid, ppvObject);
  75             //            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
  76             // .../VC/Tools/MSVC/14.14.26428/atlmfc/include\atlwin.h(2890,5):  note: expanded from
  77             //   macro 'DEFAULT_REFLECTION_HANDLER'
  78             //     if(this->DefaultReflectionHandler(hWnd, uMsg, wParam, lParam, lResult))
  79             //        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  80             return true;
  81         }
  82     }
  83     report(
  84         DiagnosticsEngine::Warning,
  85         ("accessing %select{static class member|member enumerator}0 through"
  86          " class member access syntax, use a qualified name like '%1' instead"),
  87         compat::getBeginLoc(expr))
  88         << me << decl->getQualifiedNameAsString() << expr->getSourceRange();
  89     return true;
  90 }
  91
  92 loplugin::Plugin::Registration<StaticAccess> X("staticaccess");
  93
  94 }
  95
  96 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */