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Fixed: Duck-typing in readability-redundant-smartptr-get didn't catch…
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… MSVC STL smart pointers.

Differential Revision: https://reviews.llvm.org/D61209

llvm-svn: 359801
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Florian Gross committed May 2, 2019
1 parent a558ee8 commit e25a0e9
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Showing 2 changed files with 110 additions and 13 deletions.
Expand Up @@ -30,6 +30,10 @@ internal::Matcher<Expr> callToGet(const internal::Matcher<Decl> &OnClass) {
.bind("redundant_get");
}

internal::Matcher<Decl> knownSmartptr() {
return recordDecl(hasAnyName("::std::unique_ptr", "::std::shared_ptr"));
}

void registerMatchersForGetArrowStart(MatchFinder *Finder,
MatchFinder::MatchCallback *Callback) {
const auto QuacksLikeASmartptr = recordDecl(
Expand All @@ -39,21 +43,23 @@ void registerMatchersForGetArrowStart(MatchFinder *Finder,
has(cxxMethodDecl(hasName("operator*"), returns(qualType(references(
type().bind("op*Type")))))));

// Make sure we are not missing the known standard types.
const auto Smartptr = anyOf(knownSmartptr(), QuacksLikeASmartptr);

// Catch 'ptr.get()->Foo()'
Finder->addMatcher(memberExpr(expr().bind("memberExpr"), isArrow(),
hasObjectExpression(ignoringImpCasts(
callToGet(QuacksLikeASmartptr)))),
Callback);
Finder->addMatcher(
memberExpr(expr().bind("memberExpr"), isArrow(),
hasObjectExpression(ignoringImpCasts(callToGet(Smartptr)))),
Callback);

// Catch '*ptr.get()' or '*ptr->get()'
Finder->addMatcher(
unaryOperator(hasOperatorName("*"),
hasUnaryOperand(callToGet(QuacksLikeASmartptr))),
unaryOperator(hasOperatorName("*"), hasUnaryOperand(callToGet(Smartptr))),
Callback);

// Catch '!ptr.get()'
const auto CallToGetAsBool = ignoringParenImpCasts(callToGet(recordDecl(
QuacksLikeASmartptr, has(cxxConversionDecl(returns(booleanType()))))));
const auto CallToGetAsBool = ignoringParenImpCasts(callToGet(
recordDecl(Smartptr, has(cxxConversionDecl(returns(booleanType()))))));
Finder->addMatcher(
unaryOperator(hasOperatorName("!"), hasUnaryOperand(CallToGetAsBool)),
Callback);
Expand All @@ -71,18 +77,15 @@ void registerMatchersForGetEquals(MatchFinder *Finder,
// This one is harder to do with duck typing.
// The operator==/!= that we are looking for might be member or non-member,
// might be on global namespace or found by ADL, might be a template, etc.
// For now, lets keep a list of known standard types.

const auto IsAKnownSmartptr =
recordDecl(hasAnyName("::std::unique_ptr", "::std::shared_ptr"));
// For now, lets keep it to the known standard types.

// Matches against nullptr.
Finder->addMatcher(
binaryOperator(anyOf(hasOperatorName("=="), hasOperatorName("!=")),
hasEitherOperand(ignoringImpCasts(
anyOf(cxxNullPtrLiteralExpr(), gnuNullExpr(),
integerLiteral(equals(0))))),
hasEitherOperand(callToGet(IsAKnownSmartptr))),
hasEitherOperand(callToGet(knownSmartptr()))),
Callback);

// FIXME: Match and fix if (l.get() == r.get()).
Expand Down
@@ -0,0 +1,94 @@
// RUN: %check_clang_tidy %s readability-redundant-smartptr-get %t

#define NULL __null

namespace std {

// MSVC headers define operator templates instead of plain operators.

template <typename T>
struct unique_ptr {
template <typename T2 = T>
T2& operator*() const;
template <typename T2 = T>
T2* operator->() const;
T* get() const;
explicit operator bool() const noexcept;
};

template <typename T>
struct shared_ptr {
template <typename T2 = T>
T2& operator*() const;
template <typename T2 = T>
T2* operator->() const;
T* get() const;
explicit operator bool() const noexcept;
};

} // namespace std

struct Bar {
void Do();
void ConstDo() const;
};

void Positive() {
std::unique_ptr<Bar>* up;
(*up->get()).Do();
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: redundant get() call
// CHECK-MESSAGES: (*up->get()).Do();
// CHECK-FIXES: (**up).Do();

std::unique_ptr<int> uu;
std::shared_ptr<double> *ss;
bool bb = uu.get() == nullptr;
// CHECK-MESSAGES: :[[@LINE-1]]:13: warning: redundant get() call
// CHECK-MESSAGES: uu.get() == nullptr;
// CHECK-FIXES: bool bb = uu == nullptr;

if (up->get());
// CHECK-MESSAGES: :[[@LINE-1]]:7: warning: redundant get() call
// CHECK-MESSAGES: if (up->get());
// CHECK-FIXES: if (*up);
if ((uu.get()));
// CHECK-MESSAGES: :[[@LINE-1]]:8: warning: redundant get() call
// CHECK-MESSAGES: if ((uu.get()));
// CHECK-FIXES: if ((uu));
bb = !ss->get();
// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: redundant get() call
// CHECK-MESSAGES: bb = !ss->get();
// CHECK-FIXES: bb = !*ss;

bb = nullptr != ss->get();
// CHECK-MESSAGES: :[[@LINE-1]]:19: warning: redundant get() call
// CHECK-MESSAGES: nullptr != ss->get();
// CHECK-FIXES: bb = nullptr != *ss;

bb = std::unique_ptr<int>().get() == NULL;
// CHECK-MESSAGES: :[[@LINE-1]]:8: warning: redundant get() call
// CHECK-MESSAGES: bb = std::unique_ptr<int>().get() == NULL;
// CHECK-FIXES: bb = std::unique_ptr<int>() == NULL;
bb = ss->get() == NULL;
// CHECK-MESSAGES: :[[@LINE-1]]:8: warning: redundant get() call
// CHECK-MESSAGES: bb = ss->get() == NULL;
// CHECK-FIXES: bb = *ss == NULL;

std::unique_ptr<int> x, y;
if (x.get() == nullptr);
// CHECK-MESSAGES: :[[@LINE-1]]:7: warning: redundant get() call
// CHECK-MESSAGES: if (x.get() == nullptr);
// CHECK-FIXES: if (x == nullptr);
if (nullptr == y.get());
// CHECK-MESSAGES: :[[@LINE-1]]:18: warning: redundant get() call
// CHECK-MESSAGES: if (nullptr == y.get());
// CHECK-FIXES: if (nullptr == y);
if (x.get() == NULL);
// CHECK-MESSAGES: :[[@LINE-1]]:7: warning: redundant get() call
// CHECK-MESSAGES: if (x.get() == NULL);
// CHECK-FIXES: if (x == NULL);
if (NULL == x.get());
// CHECK-MESSAGES: :[[@LINE-1]]:15: warning: redundant get() call
// CHECK-MESSAGES: if (NULL == x.get());
// CHECK-FIXES: if (NULL == x);
}

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