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 = recordDecl(
64 anyOf(hasName(
"::std::unique_ptr"), hasName(
"::std::shared_ptr")));
69 anyOf(hasOperatorName(
"=="), hasOperatorName(
"!=")),
70 hasEitherOperand(ignoringImpCasts(cxxNullPtrLiteralExpr())),
71 hasEitherOperand(callToGet(IsAKnownSmartptr))),
79 void RedundantSmartptrGetCheck::registerMatchers(MatchFinder *Finder) {
82 if (!getLangOpts().CPlusPlus)
85 registerMatchersForGetArrowStart(Finder,
this);
86 registerMatchersForGetEquals(Finder,
this);
90 bool allReturnTypesMatch(
const MatchFinder::MatchResult &
Result) {
91 if (Result.Nodes.getNodeAs<Decl>(
"duck_typing") ==
nullptr)
97 const Type *OpArrowType =
98 Result.Nodes.getNodeAs<Type>(
"op->Type")->getUnqualifiedDesugaredType();
99 const Type *OpStarType =
100 Result.Nodes.getNodeAs<Type>(
"op*Type")->getUnqualifiedDesugaredType();
101 const Type *GetType =
102 Result.Nodes.getNodeAs<Type>(
"getType")->getUnqualifiedDesugaredType();
103 return OpArrowType == OpStarType && OpArrowType == GetType;
107 void RedundantSmartptrGetCheck::check(
const MatchFinder::MatchResult &
Result) {
108 if (!allReturnTypesMatch(Result))
return;
110 bool IsPtrToPtr = Result.Nodes.getNodeAs<Decl>(
"ptr_to_ptr") !=
nullptr;
111 bool IsMemberExpr = Result.Nodes.getNodeAs<Expr>(
"memberExpr") !=
nullptr;
112 const Expr *GetCall = Result.Nodes.getNodeAs<Expr>(
"redundant_get");
113 const Expr *Smartptr = Result.Nodes.getNodeAs<Expr>(
"smart_pointer");
115 if (IsPtrToPtr && IsMemberExpr) {
120 StringRef SmartptrText = Lexer::getSourceText(
121 CharSourceRange::getTokenRange(Smartptr->getSourceRange()),
122 *Result.SourceManager, Result.Context->getLangOpts());
124 std::string Replacement = Twine(IsPtrToPtr ?
"*" :
"", SmartptrText).str();
125 diag(GetCall->getLocStart(),
"redundant get() call on smart pointer")
126 << FixItHint::CreateReplacement(GetCall->getSourceRange(), Replacement);
std::unique_ptr< ast_matchers::MatchFinder > Finder