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 RecursiveASTVisitor<StaticAccess>, public loplugin::Plugin
  47 {
  48 public:
  49     explicit StaticAccess(InstantiationData const & data): Plugin(data) {}
  50
  51     void run() override
  52     { TraverseDecl(compiler.getASTContext().getTranslationUnitDecl()); }
  53
  54     bool VisitMemberExpr(MemberExpr const * expr);
  55 };
  56
  57 bool StaticAccess::VisitMemberExpr(MemberExpr const * expr) {
  58     if (ignoreLocation(expr)) {
  59         return true;
  60     }
  61     auto decl = expr->getMemberDecl();
  62     bool me;
  63     if (!isStatic(decl, &me)) {
  64         return true;
  65     }
  66     report(
  67         DiagnosticsEngine::Warning,
  68         ("accessing %select{static class member|member enumerator}0 through"
  69          " class member access syntax, use a qualified name like '%1' instead"),
  70         expr->getLocStart())
  71         << me << decl->getQualifiedNameAsString() << expr->getSourceRange();
  72     return true;
  73 }
  74
  75 loplugin::Plugin::Registration<StaticAccess> X("staticaccess");
  76
  77 }
  78
  79 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */