11 #include "clang/ASTMatchers/ASTMatchFinder.h"
12 #include "clang/Lex/Lexer.h"
14 using namespace clang::ast_matchers;
18 namespace readability {
21 internal::Matcher<Expr> callToGet(
const internal::Matcher<Decl> &OnClass) {
22 return cxxMemberCallExpr(
23 on(expr(anyOf(hasType(OnClass),
25 pointsTo(decl(OnClass).bind(
"ptr_to_ptr"))))))
26 .bind(
"smart_pointer")),
27 unless(callee(memberExpr(hasObjectExpression(cxxThisExpr())))),
30 returns(qualType(pointsTo(type().bind(
"getType")))))))
31 .bind(
"redundant_get");
34 void registerMatchersForGetArrowStart(MatchFinder *
Finder,
35 MatchFinder::MatchCallback *Callback) {
36 const auto QuacksLikeASmartptr = recordDecl(
37 recordDecl().bind(
"duck_typing"),
38 has(cxxMethodDecl(hasName(
"operator->"),
39 returns(qualType(pointsTo(type().bind(
"op->Type")))))),
40 has(cxxMethodDecl(hasName(
"operator*"), returns(qualType(references(
41 type().bind(
"op*Type")))))));
44 Finder->addMatcher(memberExpr(expr().bind(
"memberExpr"), isArrow(),
45 hasObjectExpression(ignoringImpCasts(
46 callToGet(QuacksLikeASmartptr)))),
51 unaryOperator(hasOperatorName(
"*"),
52 hasUnaryOperand(callToGet(QuacksLikeASmartptr))),
56 void registerMatchersForGetEquals(MatchFinder *Finder,
57 MatchFinder::MatchCallback *Callback) {
63 const auto IsAKnownSmartptr =
64 recordDecl(hasAnyName(
"::std::unique_ptr",
"::std::shared_ptr"));
68 binaryOperator(anyOf(hasOperatorName(
"=="), hasOperatorName(
"!=")),
69 hasEitherOperand(ignoringImpCasts(
70 anyOf(cxxNullPtrLiteralExpr(), gnuNullExpr(),
71 integerLiteral(equals(0))))),
72 hasEitherOperand(callToGet(IsAKnownSmartptr))),
77 ifStmt(hasCondition(ignoringImpCasts(callToGet(IsAKnownSmartptr)))),
85 void RedundantSmartptrGetCheck::registerMatchers(MatchFinder *Finder) {
88 if (!getLangOpts().CPlusPlus)
91 registerMatchersForGetArrowStart(Finder,
this);
92 registerMatchersForGetEquals(Finder,
this);
96 bool allReturnTypesMatch(
const MatchFinder::MatchResult &Result) {
97 if (Result.Nodes.getNodeAs<Decl>(
"duck_typing") ==
nullptr)
103 const Type *OpArrowType =
104 Result.Nodes.getNodeAs<Type>(
"op->Type")->getUnqualifiedDesugaredType();
105 const Type *OpStarType =
106 Result.Nodes.getNodeAs<Type>(
"op*Type")->getUnqualifiedDesugaredType();
107 const Type *GetType =
108 Result.Nodes.getNodeAs<Type>(
"getType")->getUnqualifiedDesugaredType();
109 return OpArrowType == OpStarType && OpArrowType == GetType;
113 void RedundantSmartptrGetCheck::check(
const MatchFinder::MatchResult &Result) {
114 if (!allReturnTypesMatch(Result))
117 bool IsPtrToPtr = Result.Nodes.getNodeAs<Decl>(
"ptr_to_ptr") !=
nullptr;
118 bool IsMemberExpr = Result.Nodes.getNodeAs<Expr>(
"memberExpr") !=
nullptr;
119 const auto *GetCall = Result.Nodes.getNodeAs<Expr>(
"redundant_get");
120 const auto *Smartptr = Result.Nodes.getNodeAs<Expr>(
"smart_pointer");
122 if (IsPtrToPtr && IsMemberExpr) {
127 StringRef SmartptrText = Lexer::getSourceText(
128 CharSourceRange::getTokenRange(Smartptr->getSourceRange()),
129 *Result.SourceManager, getLangOpts());
131 std::string Replacement = Twine(IsPtrToPtr ?
"*" :
"", SmartptrText).str();
132 diag(GetCall->getLocStart(),
"redundant get() call on smart pointer")
133 << FixItHint::CreateReplacement(GetCall->getSourceRange(), Replacement);
std::unique_ptr< ast_matchers::MatchFinder > Finder