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 #ifndef LO_CLANG_SHARED_PLUGINS
  11
  12 #include <cassert>
  13
  14 #include "plugin.hxx"
  15
  16 namespace {
  17
  18 bool isStatic(ValueDecl const * decl, bool * memberEnumerator) {
  19     assert(memberEnumerator != nullptr);
  20     // clang::MemberExpr::getMemberDecl is documented to return either a
  21     // FieldDecl or a CXXMethodDecl, but can apparently also return a VarDecl
  22     // (as C++ static data members are modeled by VarDecl, not FieldDecl) or an
  23     // EnumConstantDecl (struct { enum {E}; } s; s.E;), see
  24     // <https://reviews.llvm.org/D23907> "Fix documentation of
  25     // MemberExpr::getMemberDecl":
  26     auto fd = dyn_cast<FieldDecl>(decl);
  27     if (fd != nullptr) {
  28         *memberEnumerator = false;
  29         return false;
  30     }
  31     auto vd = dyn_cast<VarDecl>(decl);
  32     if (vd != nullptr) {
  33         *memberEnumerator = false;
  34         assert(vd->isStaticDataMember());
  35         return true;
  36     }
  37     auto md = dyn_cast<CXXMethodDecl>(decl);
  38     if (md != nullptr) {
  39         *memberEnumerator = false;
  40         return md->isStatic();
  41     }
  42     assert(dyn_cast<EnumConstantDecl>(decl) != nullptr);
  43     *memberEnumerator = true;
  44     return true;
  45 }
  46
  47 class StaticAccess:
  48     public loplugin::FilteringPlugin<StaticAccess>
  49 {
  50 public:
  51     explicit StaticAccess(loplugin::InstantiationData const & data):
  52         FilteringPlugin(data) {}
  53
  54     void run() override
  55     { TraverseDecl(compiler.getASTContext().getTranslationUnitDecl()); }
  56
  57     bool VisitMemberExpr(MemberExpr const * expr);
  58 };
  59
  60 bool StaticAccess::VisitMemberExpr(MemberExpr const * expr) {
  61     if (ignoreLocation(expr)) {
  62         return true;
  63     }
  64     auto decl = expr->getMemberDecl();
  65     bool me;
  66     if (!isStatic(decl, &me)) {
  67         return true;
  68     }
  69     auto const loc = expr->getExprLoc();
  70     if (compiler.getSourceManager().isMacroBodyExpansion(loc)) {
  71         auto const name = Lexer::getImmediateMacroName(
  72             loc, compiler.getSourceManager(), compiler.getLangOpts());
  73         if (name == "BEGIN_COM_MAP" || name == "DEFAULT_REFLECTION_HANDLER") {
  74             // .../VC/Tools/MSVC/14.14.26428/atlmfc/include\atlcom.h(2226,10):  note: expanded from
  75             //   macro 'BEGIN_COM_MAP'
  76             //     return this->InternalQueryInterface(this, _GetEntries(), iid, ppvObject);
  77             //            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
  78             // .../VC/Tools/MSVC/14.14.26428/atlmfc/include\atlwin.h(2890,5):  note: expanded from
  79             //   macro 'DEFAULT_REFLECTION_HANDLER'
  80             //     if(this->DefaultReflectionHandler(hWnd, uMsg, wParam, lParam, lResult))
  81             //        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  82             return true;
  83         }
  84     }
  85     report(
  86         DiagnosticsEngine::Warning,
  87         ("accessing %select{static class member|member enumerator}0 through"
  88          " class member access syntax, use a qualified name like '%1' instead"),
  89         expr->getBeginLoc())
  90         << me << decl->getQualifiedNameAsString() << expr->getSourceRange();
  91     return true;
  92 }
  93
  94 loplugin::Plugin::Registration<StaticAccess> staticaccess("staticaccess");
  95
  96 } // namespace
  97
  98 #endif // LO_CLANG_SHARED_PLUGINS
  99
 100 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */