================ @@ -0,0 +1,177 @@ +//===--- CrtpConstructorAccessibilityCheck.cpp - clang-tidy +//---------------------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// + +#include "CrtpConstructorAccessibilityCheck.h" +#include "../utils/LexerUtils.h" +#include "clang/ASTMatchers/ASTMatchFinder.h" + +using namespace clang::ast_matchers; + +namespace clang::tidy::bugprone { + +static bool hasPrivateConstructor(const CXXRecordDecl *RD) { + return llvm::any_of(RD->ctors(), [](const CXXConstructorDecl *Ctor) { + return Ctor->getAccess() == AS_private; + }); +} + +static bool isDerivedParameterBefriended(const CXXRecordDecl *CRTP, + const NamedDecl *Param) { + return llvm::any_of(CRTP->friends(), [&](const FriendDecl *Friend) { + const auto *TTPT = + dyn_cast<TemplateTypeParmType>(Friend->getFriendType()->getType()); + + return TTPT && TTPT->getDecl() == Param; + }); +} + +static bool isDerivedClassBefriended(const CXXRecordDecl *CRTP, + const CXXRecordDecl *Derived) { + return llvm::any_of(CRTP->friends(), [&](const FriendDecl *Friend) { + return Friend->getFriendType()->getType()->getAsCXXRecordDecl() == Derived; + }); +} + +static const NamedDecl * +getDerivedParameter(const ClassTemplateSpecializationDecl *CRTP, + const CXXRecordDecl *Derived) { + size_t Idx = 0; + const bool AnyOf = llvm::any_of( + CRTP->getTemplateArgs().asArray(), [&](const TemplateArgument &Arg) { + ++Idx; + return Arg.getKind() == TemplateArgument::Type && + Arg.getAsType()->getAsCXXRecordDecl() == Derived; + }); + + return AnyOf ? CRTP->getSpecializedTemplate() + ->getTemplateParameters() + ->getParam(Idx - 1) + : nullptr; +} + +static std::vector<FixItHint> +hintMakeCtorPrivate(const CXXConstructorDecl *Ctor, + const std::string &OriginalAccess) { + std::vector<FixItHint> Hints; + + Hints.emplace_back(FixItHint::CreateInsertion( + Ctor->getBeginLoc().getLocWithOffset(-1), "private:\n")); + + const ASTContext &ASTCtx = Ctor->getASTContext(); + const SourceLocation CtorEndLoc = + Ctor->isExplicitlyDefaulted() + ? utils::lexer::findNextTerminator(Ctor->getEndLoc(), + ASTCtx.getSourceManager(), + ASTCtx.getLangOpts()) + : Ctor->getEndLoc(); + Hints.emplace_back(FixItHint::CreateInsertion( + CtorEndLoc.getLocWithOffset(1), '\n' + OriginalAccess + ':' + '\n')); + + return Hints; +} + +void CrtpConstructorAccessibilityCheck::registerMatchers(MatchFinder *Finder) { + Finder->addMatcher( + classTemplateSpecializationDecl( + decl().bind("crtp"), + hasAnyTemplateArgument(refersToType(recordType(hasDeclaration( + cxxRecordDecl( + isDerivedFrom(cxxRecordDecl(equalsBoundNode("crtp")))) + .bind("derived")))))), + this); +} + +void CrtpConstructorAccessibilityCheck::check( + const MatchFinder::MatchResult &Result) { + const auto *CRTPInstantiation = + Result.Nodes.getNodeAs<ClassTemplateSpecializationDecl>("crtp"); + const auto *DerivedRecord = Result.Nodes.getNodeAs<CXXRecordDecl>("derived"); + const CXXRecordDecl *CRTPDeclaration = + CRTPInstantiation->getSpecializedTemplate()->getTemplatedDecl(); + + const auto *DerivedTemplateParameter = + getDerivedParameter(CRTPInstantiation, DerivedRecord); + + assert(DerivedTemplateParameter && + "No template parameter corresponds to the derived class of the CRTP."); + + bool NeedsFriend = !isDerivedParameterBefriended(CRTPDeclaration, + DerivedTemplateParameter) && + !isDerivedClassBefriended(CRTPDeclaration, DerivedRecord); + + const FixItHint HintFriend = FixItHint::CreateInsertion( + CRTPDeclaration->getBraceRange().getEnd(), + "friend " + DerivedTemplateParameter->getNameAsString() + ';' + '\n'); + + if (hasPrivateConstructor(CRTPDeclaration) && NeedsFriend) { + diag(CRTPDeclaration->getLocation(), + "the CRTP cannot be constructed from the derived class") + << CRTPDeclaration << HintFriend; + diag(CRTPDeclaration->getLocation(), + "consider declaring the derived class as friend", DiagnosticIDs::Note); + } + + auto DiagNoteFriendPrivate = [&](const SourceLocation &Loc, bool Friend) { + return diag(Loc, + "consider making it private%select{| and declaring the " + "derived class " + "as friend}0", + DiagnosticIDs::Note) + << Friend; + }; + + auto WithFriendHintIfNeeded = [&](DiagnosticBuilder Diag, bool NeedsFriend) { + if (NeedsFriend) + Diag << HintFriend; + + return Diag; ---------------- PiotrZSL wrote:
this return value isn't used, just return void, you can take Diag as && https://github.com/llvm/llvm-project/pull/82403 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
