void StrCatAppendCheck::registerMatchers(MatchFinder *Finder) {
if (!getLangOpts().CPlusPlus)
return;
const auto StrCat = functionDecl(hasName("::absl::StrCat"));
// The arguments of absl::StrCat are implicitly converted to AlphaNum. This
// matches to the arguments because of that behavior.
const auto AlphaNum = IgnoringTemporaries(cxxConstructExpr(
argumentCountIs(1), hasType(cxxRecordDecl(hasName("::absl::AlphaNum"))),
hasArgument(0, ignoringImpCasts(declRefExpr(to(equalsBoundNode("LHS")),
expr().bind("Arg0"))))));
const auto HasAnotherReferenceToLhs =
callExpr(hasAnyArgument(expr(hasDescendant(declRefExpr(
to(equalsBoundNode("LHS")), unless(equalsBoundNode("Arg0")))))));
// Now look for calls to operator= with an object on the LHS and a call to
// StrCat on the RHS. The first argument of the StrCat call should be the same
// as the LHS. Ignore calls from template instantiations.
Finder->addMatcher(
cxxOperatorCallExpr(
unless(isInTemplateInstantiation()), hasOverloadedOperatorName("="),
hasArgument(0, declRefExpr(to(decl().bind("LHS")))),
hasArgument(1, IgnoringTemporaries(
callExpr(callee(StrCat), hasArgument(0, AlphaNum),
unless(HasAnotherReferenceToLhs))
.bind("Call"))))
.bind("Op"),
this);
}
void MakeSmartPtrCheck::registerMatchers(ast_matchers::MatchFinder *Finder) {
if (!isLanguageVersionSupported(getLangOpts()))
return;
// Calling make_smart_ptr from within a member function of a type with a
// private or protected constructor would be ill-formed.
auto CanCallCtor = unless(has(ignoringImpCasts(
cxxConstructExpr(hasDeclaration(decl(unless(isPublic())))))));
Finder->addMatcher(
cxxBindTemporaryExpr(has(ignoringParenImpCasts(
cxxConstructExpr(
hasType(getSmartPointerTypeMatcher()), argumentCountIs(1),
hasArgument(0,
cxxNewExpr(hasType(pointsTo(qualType(hasCanonicalType(
equalsBoundNode(PointerType))))),
CanCallCtor)
.bind(NewExpression)),
unless(isInTemplateInstantiation()))
.bind(ConstructorCall)))),
this);
Finder->addMatcher(
cxxMemberCallExpr(
thisPointerType(getSmartPointerTypeMatcher()),
callee(cxxMethodDecl(hasName("reset"))),
hasArgument(0, cxxNewExpr(CanCallCtor).bind(NewExpression)),
unless(isInTemplateInstantiation()))
.bind(ResetCall),
this);
}
void AssignOperatorSignatureCheck::registerMatchers(
ast_matchers::MatchFinder *Finder) {
// Only register the matchers for C++; the functionality currently does not
// provide any benefit to other languages, despite being benign.
if (getLangOpts().CPlusPlus) {
const auto HasGoodReturnType = methodDecl(returns(lValueReferenceType(
pointee(unless(isConstQualified()),
hasDeclaration(equalsBoundNode("class"))))));
const auto IsSelf = qualType(anyOf(
hasDeclaration(equalsBoundNode("class")),
referenceType(pointee(hasDeclaration(equalsBoundNode("class"))))));
const auto IsSelfAssign =
methodDecl(unless(anyOf(isDeleted(), isPrivate(), isImplicit())),
hasName("operator="), ofClass(recordDecl().bind("class")),
hasParameter(0, parmVarDecl(hasType(IsSelf))))
.bind("method");
Finder->addMatcher(
methodDecl(IsSelfAssign, unless(HasGoodReturnType)).bind("ReturnType"),
this);
const auto BadSelf = referenceType(
anyOf(lValueReferenceType(pointee(unless(isConstQualified()))),
rValueReferenceType(pointee(isConstQualified()))));
Finder->addMatcher(
methodDecl(IsSelfAssign, hasParameter(0, parmVarDecl(hasType(BadSelf))))
.bind("ArgumentType"),
this);
Finder->addMatcher(methodDecl(IsSelfAssign, isConst()).bind("Const"), this);
}
}
void SuspiciousEnumUsageCheck::registerMatchers(MatchFinder *Finder) {
const auto enumExpr = [](StringRef RefName, StringRef DeclName) {
return allOf(ignoringImpCasts(expr().bind(RefName)),
ignoringImpCasts(hasType(enumDecl().bind(DeclName))));
};
Finder->addMatcher(
binaryOperator(hasOperatorName("|"), hasLHS(enumExpr("", "enumDecl")),
hasRHS(allOf(enumExpr("", "otherEnumDecl"),
ignoringImpCasts(hasType(enumDecl(
unless(equalsBoundNode("enumDecl"))))))))
.bind("diffEnumOp"),
this);
Finder->addMatcher(
binaryOperator(anyOf(hasOperatorName("+"), hasOperatorName("|")),
hasLHS(enumExpr("lhsExpr", "enumDecl")),
hasRHS(allOf(enumExpr("rhsExpr", ""),
ignoringImpCasts(hasType(enumDecl(
equalsBoundNode("enumDecl"))))))),
this);
Finder->addMatcher(
binaryOperator(anyOf(hasOperatorName("+"), hasOperatorName("|")),
hasEitherOperand(
allOf(hasType(isInteger()), unless(enumExpr("", "")))),
hasEitherOperand(enumExpr("enumExpr", "enumDecl"))),
this);
Finder->addMatcher(
binaryOperator(anyOf(hasOperatorName("|="), hasOperatorName("+=")),
hasRHS(enumExpr("enumExpr", "enumDecl"))),
this);
}
void ShrinkToFitCheck::registerMatchers(MatchFinder *Finder) {
// Swap as a function need not to be considered, because rvalue can not
// be bound to a non-const reference.
const auto ShrinkableAsMember =
memberExpr(member(valueDecl().bind("ContainerDecl")));
const auto ShrinkableAsDecl =
declRefExpr(hasDeclaration(valueDecl().bind("ContainerDecl")));
const auto CopyCtorCall = constructExpr(
hasArgument(0, anyOf(ShrinkableAsMember, ShrinkableAsDecl,
unaryOperator(has(ShrinkableAsMember)),
unaryOperator(has(ShrinkableAsDecl)))));
const auto SwapParam = expr(anyOf(
memberExpr(member(equalsBoundNode("ContainerDecl"))),
declRefExpr(hasDeclaration(equalsBoundNode("ContainerDecl"))),
unaryOperator(has(memberExpr(member(equalsBoundNode("ContainerDecl"))))),
unaryOperator(
has(declRefExpr(hasDeclaration(equalsBoundNode("ContainerDecl")))))));
Finder->addMatcher(
memberCallExpr(on(hasType(namedDecl(stlShrinkableContainer()))),
callee(methodDecl(hasName("swap"))),
has(memberExpr(hasDescendant(CopyCtorCall))),
hasArgument(0, SwapParam.bind("ContainerToShrink")),
unless(isInTemplateInstantiation()))
.bind("CopyAndSwapTrick"),
this);
}
void DeleteNullPointerCheck::registerMatchers(MatchFinder *Finder) {
const auto DeleteExpr =
cxxDeleteExpr(has(castExpr(has(declRefExpr(
to(decl(equalsBoundNode("deletedPointer"))))))))
.bind("deleteExpr");
const auto DeleteMemberExpr =
cxxDeleteExpr(has(castExpr(has(memberExpr(hasDeclaration(
fieldDecl(equalsBoundNode("deletedMemberPointer"))))))))
.bind("deleteMemberExpr");
const auto PointerExpr = ignoringImpCasts(anyOf(
declRefExpr(to(decl().bind("deletedPointer"))),
memberExpr(hasDeclaration(fieldDecl().bind("deletedMemberPointer")))));
const auto PointerCondition = castExpr(hasCastKind(CK_PointerToBoolean),
hasSourceExpression(PointerExpr));
const auto BinaryPointerCheckCondition =
binaryOperator(hasEitherOperand(castExpr(hasCastKind(CK_NullToPointer))),
hasEitherOperand(PointerExpr));
Finder->addMatcher(
ifStmt(hasCondition(anyOf(PointerCondition, BinaryPointerCheckCondition)),
hasThen(anyOf(
DeleteExpr, DeleteMemberExpr,
compoundStmt(anyOf(has(DeleteExpr), has(DeleteMemberExpr)),
statementCountIs(1))
.bind("compound"))))
.bind("ifWithDelete"),
this);
}
void UnconventionalAssignOperatorCheck::registerMatchers(
ast_matchers::MatchFinder *Finder) {
// Only register the matchers for C++; the functionality currently does not
// provide any benefit to other languages, despite being benign.
if (!getLangOpts().CPlusPlus)
return;
const auto HasGoodReturnType = cxxMethodDecl(returns(lValueReferenceType(
pointee(unless(isConstQualified()),
anyOf(autoType(), hasDeclaration(equalsBoundNode("class")))))));
const auto IsSelf = qualType(
anyOf(hasDeclaration(equalsBoundNode("class")),
referenceType(pointee(hasDeclaration(equalsBoundNode("class"))))));
const auto IsAssign =
cxxMethodDecl(unless(anyOf(isDeleted(), isPrivate(), isImplicit())),
hasName("operator="), ofClass(recordDecl().bind("class")))
.bind("method");
const auto IsSelfAssign =
cxxMethodDecl(IsAssign, hasParameter(0, parmVarDecl(hasType(IsSelf))))
.bind("method");
Finder->addMatcher(
cxxMethodDecl(IsAssign, unless(HasGoodReturnType)).bind("ReturnType"),
this);
const auto BadSelf = referenceType(
anyOf(lValueReferenceType(pointee(unless(isConstQualified()))),
rValueReferenceType(pointee(isConstQualified()))));
Finder->addMatcher(
cxxMethodDecl(IsSelfAssign,
hasParameter(0, parmVarDecl(hasType(BadSelf))))
.bind("ArgumentType"),
this);
Finder->addMatcher(
cxxMethodDecl(IsSelfAssign, anyOf(isConst(), isVirtual())).bind("cv"),
this);
const auto IsBadReturnStatement = returnStmt(unless(has(ignoringParenImpCasts(
anyOf(unaryOperator(hasOperatorName("*"), hasUnaryOperand(cxxThisExpr())),
cxxOperatorCallExpr(argumentCountIs(1),
callee(unresolvedLookupExpr()),
hasArgument(0, cxxThisExpr())))))));
const auto IsGoodAssign = cxxMethodDecl(IsAssign, HasGoodReturnType);
Finder->addMatcher(returnStmt(IsBadReturnStatement, forFunction(IsGoodAssign))
.bind("returnStmt"),
this);
}
void SlicingCheck::registerMatchers(MatchFinder *Finder) {
// When we see:
// class B : public A { ... };
// A a;
// B b;
// a = b;
// The assignment is OK if:
// - the assignment operator is defined as taking a B as second parameter,
// or
// - B does not define any additional members (either variables or
// overrides) wrt A.
//
// The same holds for copy ctor calls. This also captures stuff like:
// void f(A a);
// f(b);
// Helpers.
const auto OfBaseClass = ofClass(cxxRecordDecl().bind("BaseDecl"));
const auto IsDerivedFromBaseDecl =
cxxRecordDecl(isDerivedFrom(equalsBoundNode("BaseDecl")))
.bind("DerivedDecl");
const auto HasTypeDerivedFromBaseDecl =
anyOf(hasType(IsDerivedFromBaseDecl),
hasType(references(IsDerivedFromBaseDecl)));
const auto IsWithinDerivedCtor =
hasParent(cxxConstructorDecl(ofClass(equalsBoundNode("DerivedDecl"))));
// Assignement slicing: "a = b;" and "a = std::move(b);" variants.
const auto SlicesObjectInAssignment =
callExpr(callee(cxxMethodDecl(anyOf(isCopyAssignmentOperator(),
isMoveAssignmentOperator()),
OfBaseClass)),
hasArgument(1, HasTypeDerivedFromBaseDecl));
// Construction slicing: "A a{b};" and "f(b);" variants. Note that in case of
// slicing the letter will create a temporary and therefore call a ctor.
const auto SlicesObjectInCtor = cxxConstructExpr(
hasDeclaration(cxxConstructorDecl(
anyOf(isCopyConstructor(), isMoveConstructor()), OfBaseClass)),
hasArgument(0, HasTypeDerivedFromBaseDecl),
// We need to disable matching on the call to the base copy/move
// constructor in DerivedDecl's constructors.
unless(IsWithinDerivedCtor));
Finder->addMatcher(
expr(anyOf(SlicesObjectInAssignment, SlicesObjectInCtor)).bind("Call"),
this);
}
void InefficientAlgorithmCheck::registerMatchers(MatchFinder *Finder) {
// Only register the matchers for C++; the functionality currently does not
// provide any benefit to other languages, despite being benign.
if (!getLangOpts().CPlusPlus)
return;
const std::string Algorithms =
"^::std::(find|count|equal_range|lower_bound|upper_bound)$";
const auto ContainerMatcher = classTemplateSpecializationDecl(
matchesName("^::std::(unordered_)?(multi)?(set|map)$"));
const auto Matcher =
callExpr(
callee(functionDecl(matchesName(Algorithms))),
hasArgument(
0, constructExpr(has(memberCallExpr(
callee(methodDecl(hasName("begin"))),
on(declRefExpr(
hasDeclaration(decl().bind("IneffContObj")),
anyOf(hasType(ContainerMatcher.bind("IneffCont")),
hasType(pointsTo(
ContainerMatcher.bind("IneffContPtr")))))
.bind("IneffContExpr")))))),
hasArgument(1, constructExpr(has(memberCallExpr(
callee(methodDecl(hasName("end"))),
on(declRefExpr(hasDeclaration(
equalsBoundNode("IneffContObj")))))))),
hasArgument(2, expr().bind("AlgParam")),
unless(isInTemplateInstantiation()))
.bind("IneffAlg");
Finder->addMatcher(Matcher, this);
}
void SizeofContainerCheck::registerMatchers(MatchFinder *Finder) {
Finder->addMatcher(
expr(unless(isInTemplateInstantiation()),
expr(sizeOfExpr(has(ignoringParenImpCasts(
expr(hasType(hasCanonicalType(hasDeclaration(cxxRecordDecl(
matchesName("^(::std::|::string)"),
unless(matchesName("^::std::(bitset|array)$")),
hasMethod(cxxMethodDecl(hasName("size"), isPublic(),
isConst())))))))))))
.bind("sizeof"),
// Ignore ARRAYSIZE(<array of containers>) pattern.
unless(hasAncestor(binaryOperator(
anyOf(hasOperatorName("/"), hasOperatorName("%")),
hasLHS(ignoringParenCasts(sizeOfExpr(expr()))),
hasRHS(ignoringParenCasts(equalsBoundNode("sizeof"))))))),
this);
}
void InefficientStringConcatenationCheck::registerMatchers(
MatchFinder *Finder) {
if (!getLangOpts().CPlusPlus)
return;
const auto BasicStringType =
hasType(qualType(hasUnqualifiedDesugaredType(recordType(
hasDeclaration(cxxRecordDecl(hasName("::std::basic_string")))))));
const auto BasicStringPlusOperator = cxxOperatorCallExpr(
hasOverloadedOperatorName("+"),
hasAnyArgument(ignoringImpCasts(declRefExpr(BasicStringType))));
const auto PlusOperator =
cxxOperatorCallExpr(
hasOverloadedOperatorName("+"),
hasAnyArgument(ignoringImpCasts(declRefExpr(BasicStringType))),
hasDescendant(BasicStringPlusOperator))
.bind("plusOperator");
const auto AssignOperator = cxxOperatorCallExpr(
hasOverloadedOperatorName("="),
hasArgument(0, declRefExpr(BasicStringType,
hasDeclaration(decl().bind("lhsStrT")))
.bind("lhsStr")),
hasArgument(1, stmt(hasDescendant(declRefExpr(
hasDeclaration(decl(equalsBoundNode("lhsStrT"))))))),
hasDescendant(BasicStringPlusOperator));
if (StrictMode) {
Finder->addMatcher(cxxOperatorCallExpr(anyOf(AssignOperator, PlusOperator)),
this);
} else {
Finder->addMatcher(
cxxOperatorCallExpr(anyOf(AssignOperator, PlusOperator),
hasAncestor(stmt(anyOf(cxxForRangeStmt(),
whileStmt(), forStmt())))),
this);
}
}
