10#include "../utils/LexerUtils.h"
11#include "clang/ASTMatchers/ASTMatchFinder.h"
18 return llvm::any_of(RD->ctors(), [](
const CXXConstructorDecl *Ctor) {
19 return Ctor->getAccess() == AS_private;
24 const NamedDecl *Param) {
25 return llvm::any_of(CRTP->friends(), [&](
const FriendDecl *Friend) {
26 const TypeSourceInfo *const FriendType = Friend->getFriendType();
31 const auto *
const TTPT =
32 dyn_cast<TemplateTypeParmType>(FriendType->getType());
34 return TTPT && TTPT->getDecl() == Param;
39 const CXXRecordDecl *Derived) {
40 return llvm::any_of(CRTP->friends(), [&](
const FriendDecl *Friend) {
41 const TypeSourceInfo *const FriendType = Friend->getFriendType();
46 return FriendType->getType()->getAsCXXRecordDecl() == Derived;
50static const NamedDecl *
52 const CXXRecordDecl *Derived) {
54 const bool AnyOf = llvm::any_of(
55 CRTP->getTemplateArgs().asArray(), [&](
const TemplateArgument &Arg) {
57 return Arg.getKind() == TemplateArgument::Type &&
58 Arg.getAsType()->getAsCXXRecordDecl() == Derived;
61 return AnyOf ? CRTP->getSpecializedTemplate()
62 ->getTemplateParameters()
67static std::vector<FixItHint>
69 const std::string &OriginalAccess) {
70 std::vector<FixItHint>
Hints;
72 Hints.emplace_back(FixItHint::CreateInsertion(
73 Ctor->getBeginLoc().getLocWithOffset(-1),
"private:\n"));
75 const ASTContext &ASTCtx = Ctor->getASTContext();
76 const SourceLocation CtorEndLoc =
77 Ctor->isExplicitlyDefaulted()
78 ? utils::lexer::findNextTerminator(Ctor->getEndLoc(),
79 ASTCtx.getSourceManager(),
82 Hints.emplace_back(FixItHint::CreateInsertion(
83 CtorEndLoc.getLocWithOffset(1),
'\n' + OriginalAccess +
':' +
'\n'));
88void CrtpConstructorAccessibilityCheck::registerMatchers(MatchFinder *Finder) {
90 classTemplateSpecializationDecl(
92 hasAnyTemplateArgument(refersToType(recordType(hasDeclaration(
94 isDerivedFrom(cxxRecordDecl(equalsBoundNode(
"crtp"))))
95 .bind(
"derived")))))),
99void CrtpConstructorAccessibilityCheck::check(
100 const MatchFinder::MatchResult &Result) {
101 const auto *CRTPInstantiation =
102 Result.Nodes.getNodeAs<ClassTemplateSpecializationDecl>(
"crtp");
103 const auto *DerivedRecord = Result.Nodes.getNodeAs<CXXRecordDecl>(
"derived");
104 const CXXRecordDecl *CRTPDeclaration =
105 CRTPInstantiation->getSpecializedTemplate()->getTemplatedDecl();
107 if (!CRTPDeclaration->hasDefinition()) {
111 const auto *DerivedTemplateParameter =
114 assert(DerivedTemplateParameter &&
115 "No template parameter corresponds to the derived class of the CRTP.");
118 DerivedTemplateParameter) &&
121 const FixItHint HintFriend = FixItHint::CreateInsertion(
122 CRTPDeclaration->getBraceRange().getEnd(),
123 "friend " + DerivedTemplateParameter->getNameAsString() +
';' +
'\n');
126 diag(CRTPDeclaration->getLocation(),
127 "the CRTP cannot be constructed from the derived class; consider "
128 "declaring the derived class as friend")
132 auto WithFriendHintIfNeeded =
133 [&](
const DiagnosticBuilder &Diag,
134 bool NeedsFriend) ->
const DiagnosticBuilder & {
141 if (!CRTPDeclaration->hasUserDeclaredConstructor()) {
142 const bool IsStruct = CRTPDeclaration->isStruct();
144 WithFriendHintIfNeeded(
145 diag(CRTPDeclaration->getLocation(),
146 "the implicit default constructor of the CRTP is publicly "
147 "accessible; consider making it private%select{| and declaring "
148 "the derived class as friend}0")
150 << FixItHint::CreateInsertion(
151 CRTPDeclaration->getBraceRange().getBegin().getLocWithOffset(
153 (IsStruct ?
"\nprivate:\n" :
"\n") +
154 CRTPDeclaration->getNameAsString() +
"() = default;\n" +
155 (IsStruct ?
"public:\n" :
"")),
159 for (
auto &&Ctor : CRTPDeclaration->ctors()) {
160 if (Ctor->getAccess() == AS_private)
163 const bool IsPublic = Ctor->getAccess() == AS_public;
164 const std::string Access = IsPublic ?
"public" :
"protected";
166 WithFriendHintIfNeeded(
167 diag(Ctor->getLocation(),
168 "%0 constructor allows the CRTP to be %select{inherited "
169 "from|constructed}1 as a regular template class; consider making "
170 "it private%select{| and declaring the derived class as friend}2")
171 << Access << IsPublic << NeedsFriend
177bool CrtpConstructorAccessibilityCheck::isLanguageVersionSupported(
178 const LangOptions &LangOpts)
const {
179 return LangOpts.CPlusPlus11;
std::vector< FixItHint > Hints
static bool hasPrivateConstructor(const CXXRecordDecl *RD)
static std::vector< FixItHint > hintMakeCtorPrivate(const CXXConstructorDecl *Ctor, const std::string &OriginalAccess)
static bool isDerivedParameterBefriended(const CXXRecordDecl *CRTP, const NamedDecl *Param)
static bool isDerivedClassBefriended(const CXXRecordDecl *CRTP, const CXXRecordDecl *Derived)
static const NamedDecl * getDerivedParameter(const ClassTemplateSpecializationDecl *CRTP, const CXXRecordDecl *Derived)