11 #include "clang/Frontend/CompilerInstance.h"
12 #include "clang/Lex/Lexer.h"
14 using namespace clang::ast_matchers;
21 bool protoTypeHasNoParms(QualType QT) {
23 QT = PT->getPointeeType();
25 if (
auto *MPT = QT->getAs<MemberPointerType>()) {
26 QT = MPT->getPointeeType();
28 if (
auto FP = QT->getAs<FunctionProtoType>()) {
29 return FP->getNumParams() == 0;
34 const char FunctionId[] =
"function";
35 const char TypedefId[] =
"typedef";
36 const char FieldId[] =
"field";
37 const char VarId[] =
"var";
38 const char NamedCastId[] =
"named-cast";
39 const char CStyleCastId[] =
"c-style-cast";
40 const char ExplicitCastId[] =
"explicit-cast";
41 const char LambdaId[] =
"lambda";
48 void RedundantVoidArgCheck::registerMatchers(MatchFinder *
Finder) {
49 Finder->addMatcher(functionDecl(isExpansionInMainFile(), parameterCountIs(0),
50 unless(isImplicit()), unless(isExternC()))
53 Finder->addMatcher(typedefDecl(isExpansionInMainFile()).bind(TypedefId),
55 auto ParenFunctionType = parenType(innerType(functionType()));
56 auto PointerToFunctionType = pointee(ParenFunctionType);
57 auto FunctionOrMemberPointer =
58 anyOf(hasType(pointerType(PointerToFunctionType)),
59 hasType(memberPointerType(PointerToFunctionType)));
61 fieldDecl(isExpansionInMainFile(), FunctionOrMemberPointer).bind(FieldId),
64 varDecl(isExpansionInMainFile(), FunctionOrMemberPointer).bind(VarId),
66 auto CastDestinationIsFunction =
67 hasDestinationType(pointsTo(ParenFunctionType));
69 cStyleCastExpr(isExpansionInMainFile(), CastDestinationIsFunction)
73 cxxStaticCastExpr(isExpansionInMainFile(), CastDestinationIsFunction)
77 cxxReinterpretCastExpr(isExpansionInMainFile(), CastDestinationIsFunction)
81 cxxConstCastExpr(isExpansionInMainFile(), CastDestinationIsFunction)
84 Finder->addMatcher(lambdaExpr(isExpansionInMainFile()).bind(LambdaId),
this);
87 void RedundantVoidArgCheck::check(
const MatchFinder::MatchResult &
Result) {
88 if (!Result.Context->getLangOpts().CPlusPlus) {
92 const BoundNodes &Nodes = Result.Nodes;
93 if (
const auto *Function = Nodes.getNodeAs<FunctionDecl>(FunctionId)) {
94 processFunctionDecl(Result, Function);
95 }
else if (
const auto *Typedef = Nodes.getNodeAs<TypedefDecl>(TypedefId)) {
96 processTypedefDecl(Result, Typedef);
97 }
else if (
const auto *Member = Nodes.getNodeAs<FieldDecl>(FieldId)) {
98 processFieldDecl(Result, Member);
99 }
else if (
const auto *Var = Nodes.getNodeAs<VarDecl>(VarId)) {
100 processVarDecl(Result, Var);
101 }
else if (
const auto *NamedCast =
102 Nodes.getNodeAs<CXXNamedCastExpr>(NamedCastId)) {
103 processNamedCastExpr(Result, NamedCast);
104 }
else if (
const auto *CStyleCast =
105 Nodes.getNodeAs<CStyleCastExpr>(CStyleCastId)) {
106 processExplicitCastExpr(Result, CStyleCast);
107 }
else if (
const auto *ExplicitCast =
108 Nodes.getNodeAs<ExplicitCastExpr>(ExplicitCastId)) {
109 processExplicitCastExpr(Result, ExplicitCast);
110 }
else if (
const auto *Lambda = Nodes.getNodeAs<LambdaExpr>(LambdaId)) {
111 processLambdaExpr(Result, Lambda);
115 void RedundantVoidArgCheck::processFunctionDecl(
116 const MatchFinder::MatchResult &
Result,
const FunctionDecl *Function) {
117 SourceLocation Start = Function->getLocStart();
118 if (Function->isThisDeclarationADefinition()) {
120 if (Function->hasBody())
121 End = Function->getBody()->getLocStart().getLocWithOffset(-1);
123 End = Function->getLocEnd();
124 removeVoidArgumentTokens(Result, SourceRange(Start, End),
125 "function definition");
127 removeVoidArgumentTokens(Result, Function->getSourceRange(),
128 "function declaration");
132 void RedundantVoidArgCheck::removeVoidArgumentTokens(
133 const ast_matchers::MatchFinder::MatchResult &Result, SourceRange
Range,
134 StringRef GrammarLocation) {
135 CharSourceRange CharRange = Lexer::makeFileCharRange(
136 CharSourceRange::getTokenRange(Range), *Result.SourceManager,
137 Result.Context->getLangOpts());
139 std::string DeclText = Lexer::getSourceText(CharRange, *Result.SourceManager,
140 Result.Context->getLangOpts())
142 Lexer PrototypeLexer(CharRange.getBegin(), Result.Context->getLangOpts(),
143 DeclText.data(), DeclText.data(),
144 DeclText.data() + DeclText.size());
150 TokenState State = NothingYet;
153 std::string Diagnostic =
154 (
"redundant void argument list in " + GrammarLocation).str();
156 while (!PrototypeLexer.LexFromRawLexer(ProtoToken)) {
159 if (ProtoToken.is(tok::TokenKind::l_paren)) {
160 State = SawLeftParen;
164 if (ProtoToken.is(tok::TokenKind::raw_identifier) &&
165 ProtoToken.getRawIdentifier() ==
"void") {
167 VoidToken = ProtoToken;
174 if (ProtoToken.is(tok::TokenKind::r_paren)) {
175 removeVoidToken(VoidToken, Diagnostic);
176 }
else if (ProtoToken.is(tok::TokenKind::l_paren)) {
177 State = SawLeftParen;
183 if (State == SawVoid && ProtoToken.is(tok::TokenKind::r_paren)) {
184 removeVoidToken(VoidToken, Diagnostic);
188 void RedundantVoidArgCheck::removeVoidToken(Token VoidToken,
189 StringRef Diagnostic) {
190 SourceLocation VoidLoc(VoidToken.getLocation());
192 CharSourceRange::getTokenRange(VoidLoc, VoidLoc.getLocWithOffset(3));
193 diag(VoidLoc, Diagnostic) << FixItHint::CreateRemoval(VoidRange);
196 void RedundantVoidArgCheck::processTypedefDecl(
197 const MatchFinder::MatchResult &Result,
const TypedefDecl *Typedef) {
198 if (protoTypeHasNoParms(Typedef->getUnderlyingType())) {
199 removeVoidArgumentTokens(Result, Typedef->getSourceRange(),
"typedef");
203 void RedundantVoidArgCheck::processFieldDecl(
204 const MatchFinder::MatchResult &Result,
const FieldDecl *Member) {
205 if (protoTypeHasNoParms(Member->getType())) {
206 removeVoidArgumentTokens(Result, Member->getSourceRange(),
207 "field declaration");
211 void RedundantVoidArgCheck::processVarDecl(
212 const MatchFinder::MatchResult &Result,
const VarDecl *Var) {
213 if (protoTypeHasNoParms(Var->getType())) {
214 SourceLocation Begin = Var->getLocStart();
215 if (Var->hasInit()) {
216 SourceLocation InitStart =
217 Result.SourceManager->getExpansionLoc(Var->getInit()->getLocStart())
218 .getLocWithOffset(-1);
219 removeVoidArgumentTokens(Result, SourceRange(Begin, InitStart),
220 "variable declaration with initializer");
222 removeVoidArgumentTokens(Result, Var->getSourceRange(),
223 "variable declaration");
228 void RedundantVoidArgCheck::processNamedCastExpr(
229 const MatchFinder::MatchResult &Result,
const CXXNamedCastExpr *NamedCast) {
230 if (protoTypeHasNoParms(NamedCast->getTypeAsWritten())) {
231 removeVoidArgumentTokens(
233 NamedCast->getTypeInfoAsWritten()->getTypeLoc().getSourceRange(),
238 void RedundantVoidArgCheck::processExplicitCastExpr(
239 const MatchFinder::MatchResult &Result,
240 const ExplicitCastExpr *ExplicitCast) {
241 if (protoTypeHasNoParms(ExplicitCast->getTypeAsWritten())) {
242 removeVoidArgumentTokens(Result, ExplicitCast->getSourceRange(),
247 void RedundantVoidArgCheck::processLambdaExpr(
248 const MatchFinder::MatchResult &Result,
const LambdaExpr *Lambda) {
249 if (Lambda->getLambdaClass()->getLambdaCallOperator()->getNumParams() == 0 &&
250 Lambda->hasExplicitParameters()) {
251 SourceLocation Begin =
252 Lambda->getIntroducerRange().getEnd().getLocWithOffset(1);
253 SourceLocation End = Lambda->getBody()->getLocStart().getLocWithOffset(-1);
254 removeVoidArgumentTokens(Result, SourceRange(Begin, End),
255 "lambda expression");
std::unique_ptr< ast_matchers::MatchFinder > Finder
static const char PointerType[]
CharSourceRange Range
SourceRange for the file name.