build/clang-plugin/NoDuplicateRefCntMemberChecker.cpp

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 #include "NoDuplicateRefCntMemberChecker.h"
   6 #include "CustomMatchers.h"
   7
   8 void NoDuplicateRefCntMemberChecker::registerMatchers(MatchFinder *AstMatcher) {
   9   AstMatcher->addMatcher(cxxRecordDecl().bind("decl"), this);
  10 }
  11
  12 void NoDuplicateRefCntMemberChecker::check(
  13     const MatchFinder::MatchResult &Result) {
  14   const CXXRecordDecl *D = Result.Nodes.getNodeAs<CXXRecordDecl>("decl");
  15   const FieldDecl *RefCntMember = getClassRefCntMember(D);
  16   const FieldDecl *FoundRefCntBase = nullptr;
  17
  18   if (!D->hasDefinition())
  19     return;
  20   D = D->getDefinition();
  21
  22   // If we don't have an mRefCnt member, and we have less than 2 superclasses,
  23   // we don't have to run this loop, as neither case will ever apply.
  24   if (!RefCntMember && D->getNumBases() < 2) {
  25     return;
  26   }
  27
  28   // Check every superclass for whether it has a base with a refcnt member, and
  29   // warn for those which do
  30   for (auto &Base : D->bases()) {
  31     // Determine if this base class has an mRefCnt member
  32     const FieldDecl *BaseRefCntMember = getBaseRefCntMember(Base.getType());
  33
  34     if (BaseRefCntMember) {
  35       if (RefCntMember) {
  36         // We have an mRefCnt, and superclass has an mRefCnt
  37         const char *Error = "Refcounted record %0 has multiple mRefCnt members";
  38         const char *Note1 = "Superclass %0 also has an mRefCnt member";
  39         const char *Note2 =
  40             "Consider using the _INHERITED macros for AddRef and Release here";
  41
  42         diag(D->getBeginLoc(), Error, DiagnosticIDs::Error) << D;
  43         diag(BaseRefCntMember->getBeginLoc(), Note1, DiagnosticIDs::Note)
  44             << BaseRefCntMember->getParent();
  45         diag(RefCntMember->getBeginLoc(), Note2, DiagnosticIDs::Note);
  46       }
  47
  48       if (FoundRefCntBase) {
  49         const char *Error = "Refcounted record %0 has multiple superclasses "
  50                             "with mRefCnt members";
  51         const char *Note = "Superclass %0 has an mRefCnt member";
  52
  53         // superclass has mRefCnt, and another superclass also has an mRefCnt
  54         diag(D->getBeginLoc(), Error, DiagnosticIDs::Error) << D;
  55         diag(BaseRefCntMember->getBeginLoc(), Note, DiagnosticIDs::Note)
  56             << BaseRefCntMember->getParent();
  57         diag(FoundRefCntBase->getBeginLoc(), Note, DiagnosticIDs::Note)
  58             << FoundRefCntBase->getParent();
  59       }
  60
  61       // Record that we've found a base with a mRefCnt member
  62       FoundRefCntBase = BaseRefCntMember;
  63     }
  64   }
  65 }