10 #include "clang/Frontend/CompilerInstance.h"
11 #include "clang/Lex/Lexer.h"
22 bool protoTypeHasNoParms(QualType QT) {
23 if (
auto PT = QT->getAs<PointerType>()) {
24 QT = PT->getPointeeType();
26 if (
auto *MPT = QT->getAs<MemberPointerType>()) {
27 QT = MPT->getPointeeType();
29 if (
auto FP = QT->getAs<FunctionProtoType>()) {
30 return FP->getNumParams() == 0;
35 const char FunctionId[] =
"function";
36 const char TypedefId[] =
"typedef";
38 const char VarId[] =
"var";
39 const char NamedCastId[] =
"named-cast";
40 const char CStyleCastId[] =
"c-style-cast";
41 const char ExplicitCastId[] =
"explicit-cast";
42 const char LambdaId[] =
"lambda";
46 void RedundantVoidArgCheck::registerMatchers(MatchFinder *Finder) {
47 Finder->addMatcher(functionDecl(parameterCountIs(0), unless(isImplicit()),
48 unless(isInstantiated()), unless(isExternC()))
51 Finder->addMatcher(typedefNameDecl().bind(TypedefId),
this);
52 auto ParenFunctionType = parenType(innerType(functionType()));
53 auto PointerToFunctionType = pointee(ParenFunctionType);
54 auto FunctionOrMemberPointer =
55 anyOf(hasType(pointerType(PointerToFunctionType)),
56 hasType(memberPointerType(PointerToFunctionType)));
57 Finder->addMatcher(fieldDecl(FunctionOrMemberPointer).bind(
FieldId),
this);
58 Finder->addMatcher(varDecl(FunctionOrMemberPointer).bind(VarId),
this);
59 auto CastDestinationIsFunction =
60 hasDestinationType(pointsTo(ParenFunctionType));
62 cStyleCastExpr(CastDestinationIsFunction).bind(CStyleCastId),
this);
64 cxxStaticCastExpr(CastDestinationIsFunction).bind(NamedCastId),
this);
66 cxxReinterpretCastExpr(CastDestinationIsFunction).bind(NamedCastId),
69 cxxConstCastExpr(CastDestinationIsFunction).bind(NamedCastId),
this);
70 Finder->addMatcher(lambdaExpr().bind(LambdaId),
this);
73 void RedundantVoidArgCheck::check(
const MatchFinder::MatchResult &Result) {
74 const BoundNodes &Nodes = Result.Nodes;
75 if (
const auto *Function = Nodes.getNodeAs<FunctionDecl>(FunctionId)) {
76 processFunctionDecl(Result, Function);
77 }
else if (
const auto *TypedefName =
78 Nodes.getNodeAs<TypedefNameDecl>(TypedefId)) {
79 processTypedefNameDecl(Result, TypedefName);
80 }
else if (
const auto *Member = Nodes.getNodeAs<FieldDecl>(
FieldId)) {
81 processFieldDecl(Result, Member);
82 }
else if (
const auto *Var = Nodes.getNodeAs<VarDecl>(VarId)) {
83 processVarDecl(Result, Var);
84 }
else if (
const auto *NamedCast =
85 Nodes.getNodeAs<CXXNamedCastExpr>(NamedCastId)) {
86 processNamedCastExpr(Result, NamedCast);
87 }
else if (
const auto *CStyleCast =
88 Nodes.getNodeAs<CStyleCastExpr>(CStyleCastId)) {
89 processExplicitCastExpr(Result, CStyleCast);
90 }
else if (
const auto *ExplicitCast =
91 Nodes.getNodeAs<ExplicitCastExpr>(ExplicitCastId)) {
92 processExplicitCastExpr(Result, ExplicitCast);
93 }
else if (
const auto *Lambda = Nodes.getNodeAs<LambdaExpr>(LambdaId)) {
94 processLambdaExpr(Result, Lambda);
98 void RedundantVoidArgCheck::processFunctionDecl(
99 const MatchFinder::MatchResult &Result,
const FunctionDecl *Function) {
100 if (Function->isThisDeclarationADefinition()) {
101 SourceLocation Start = Function->getBeginLoc();
102 SourceLocation End = Function->getEndLoc();
103 if (
const Stmt *Body = Function->getBody()) {
104 End = Body->getBeginLoc();
105 if (End.isMacroID() &&
106 Result.SourceManager->isAtStartOfImmediateMacroExpansion(End))
107 End = Result.SourceManager->getExpansionLoc(End);
108 End = End.getLocWithOffset(-1);
110 removeVoidArgumentTokens(Result, SourceRange(Start, End),
111 "function definition");
113 removeVoidArgumentTokens(Result, Function->getSourceRange(),
114 "function declaration");
118 void RedundantVoidArgCheck::removeVoidArgumentTokens(
119 const ast_matchers::MatchFinder::MatchResult &Result, SourceRange
Range,
120 StringRef GrammarLocation) {
121 CharSourceRange CharRange =
122 Lexer::makeFileCharRange(CharSourceRange::getTokenRange(
Range),
123 *Result.SourceManager, getLangOpts());
125 std::string DeclText =
126 Lexer::getSourceText(CharRange, *Result.SourceManager, getLangOpts())
128 Lexer PrototypeLexer(CharRange.getBegin(), getLangOpts(), DeclText.data(),
129 DeclText.data(), DeclText.data() + DeclText.size());
135 TokenState State = NothingYet;
139 (
"redundant void argument list in " + GrammarLocation).str();
141 while (!PrototypeLexer.LexFromRawLexer(ProtoToken)) {
144 if (ProtoToken.is(tok::TokenKind::l_paren)) {
145 State = SawLeftParen;
149 if (ProtoToken.is(tok::TokenKind::raw_identifier) &&
150 ProtoToken.getRawIdentifier() ==
"void") {
152 VoidToken = ProtoToken;
153 }
else if (ProtoToken.is(tok::TokenKind::l_paren)) {
154 State = SawLeftParen;
161 if (ProtoToken.is(tok::TokenKind::r_paren)) {
163 }
else if (ProtoToken.is(tok::TokenKind::l_paren)) {
164 State = SawLeftParen;
170 if (State == SawVoid && ProtoToken.is(tok::TokenKind::r_paren)) {
175 void RedundantVoidArgCheck::removeVoidToken(Token VoidToken,
177 SourceLocation VoidLoc = VoidToken.getLocation();
178 diag(VoidLoc,
Diagnostic) << FixItHint::CreateRemoval(VoidLoc);
181 void RedundantVoidArgCheck::processTypedefNameDecl(
182 const MatchFinder::MatchResult &Result,
183 const TypedefNameDecl *TypedefName) {
184 if (protoTypeHasNoParms(TypedefName->getUnderlyingType())) {
185 removeVoidArgumentTokens(Result, TypedefName->getSourceRange(),
186 isa<TypedefDecl>(TypedefName) ?
"typedef"
191 void RedundantVoidArgCheck::processFieldDecl(
192 const MatchFinder::MatchResult &Result,
const FieldDecl *Member) {
193 if (protoTypeHasNoParms(Member->getType())) {
194 removeVoidArgumentTokens(Result, Member->getSourceRange(),
195 "field declaration");
199 void RedundantVoidArgCheck::processVarDecl(
200 const MatchFinder::MatchResult &Result,
const VarDecl *Var) {
201 if (protoTypeHasNoParms(Var->getType())) {
202 SourceLocation Begin = Var->getBeginLoc();
203 if (Var->hasInit()) {
204 SourceLocation InitStart =
205 Result.SourceManager->getExpansionLoc(Var->getInit()->getBeginLoc())
206 .getLocWithOffset(-1);
207 removeVoidArgumentTokens(Result, SourceRange(Begin, InitStart),
208 "variable declaration with initializer");
210 removeVoidArgumentTokens(Result, Var->getSourceRange(),
211 "variable declaration");
216 void RedundantVoidArgCheck::processNamedCastExpr(
217 const MatchFinder::MatchResult &Result,
const CXXNamedCastExpr *NamedCast) {
218 if (protoTypeHasNoParms(NamedCast->getTypeAsWritten())) {
219 removeVoidArgumentTokens(
221 NamedCast->getTypeInfoAsWritten()->getTypeLoc().getSourceRange(),
226 void RedundantVoidArgCheck::processExplicitCastExpr(
227 const MatchFinder::MatchResult &Result,
228 const ExplicitCastExpr *ExplicitCast) {
229 if (protoTypeHasNoParms(ExplicitCast->getTypeAsWritten())) {
230 removeVoidArgumentTokens(Result, ExplicitCast->getSourceRange(),
235 void RedundantVoidArgCheck::processLambdaExpr(
236 const MatchFinder::MatchResult &Result,
const LambdaExpr *Lambda) {
237 if (Lambda->getLambdaClass()->getLambdaCallOperator()->getNumParams() == 0 &&
238 Lambda->hasExplicitParameters()) {
239 SourceManager *SM = Result.SourceManager;
240 TypeLoc TL = Lambda->getLambdaClass()->getLambdaTypeInfo()->getTypeLoc();
241 removeVoidArgumentTokens(Result,
242 {SM->getSpellingLoc(TL.getBeginLoc()),
243 SM->getSpellingLoc(TL.getEndLoc())},
244 "lambda expression");