11 #include "clang/Lex/Lexer.h" 12 #include "llvm/Support/raw_ostream.h" 23 const ParmVarDecl *ParmVar,
24 const TemplateTypeParmDecl *TypeParmDecl,
25 DiagnosticBuilder &Diag,
26 const ASTContext &Context) {
27 const SourceManager &SM = Context.getSourceManager();
28 const LangOptions &LangOpts = Context.getLangOpts();
30 CharSourceRange CallRange =
31 Lexer::makeFileCharRange(CharSourceRange::getTokenRange(
32 Callee->getLocStart(), Callee->getLocEnd()),
35 if (CallRange.isValid()) {
36 const std::string TypeName =
37 TypeParmDecl->getIdentifier()
38 ? TypeParmDecl->getName().str()
39 : (llvm::Twine(
"decltype(") + ParmVar->getName() +
")").str();
41 const std::string ForwardName =
42 (llvm::Twine(
"forward<") + TypeName +
">").str();
48 NestedNameSpecifier *NNS = Callee->getQualifier();
53 Diag << FixItHint::CreateReplacement(CallRange,
"std::" + ForwardName);
54 }
else if (
const NamespaceDecl *Namespace = NNS->getAsNamespace()) {
55 if (Namespace->getName() ==
"std") {
56 if (!NNS->getPrefix()) {
58 Diag << FixItHint::CreateReplacement(CallRange,
59 "std::" + ForwardName);
60 }
else if (NNS->getPrefix()->getKind() == NestedNameSpecifier::Global) {
62 Diag << FixItHint::CreateReplacement(CallRange,
63 "::std::" + ForwardName);
70 void MoveForwardingReferenceCheck::registerMatchers(MatchFinder *Finder) {
71 if (!getLangOpts().CPlusPlus11)
76 auto ForwardingReferenceParmMatcher =
78 hasType(qualType(rValueReferenceType(),
79 references(templateTypeParmType(hasDeclaration(
80 templateTypeParmDecl().bind(
"type-parm-decl")))),
81 unless(references(qualType(isConstQualified()))))))
85 callExpr(callee(unresolvedLookupExpr(
86 hasAnyDeclaration(namedDecl(
87 hasUnderlyingDecl(hasName(
"::std::move")))))
90 hasArgument(0, ignoringParenImpCasts(declRefExpr(
91 to(ForwardingReferenceParmMatcher)))))
96 void MoveForwardingReferenceCheck::check(
97 const MatchFinder::MatchResult &Result) {
98 const auto *CallMove = Result.Nodes.getNodeAs<CallExpr>(
"call-move");
99 const auto *UnresolvedLookup =
100 Result.Nodes.getNodeAs<UnresolvedLookupExpr>(
"lookup");
101 const auto *ParmVar = Result.Nodes.getNodeAs<ParmVarDecl>(
"parm-var");
102 const auto *TypeParmDecl =
103 Result.Nodes.getNodeAs<TemplateTypeParmDecl>(
"type-parm-decl");
107 const auto *FuncForParam = dyn_cast<FunctionDecl>(ParmVar->getDeclContext());
110 const FunctionTemplateDecl *FuncTemplate =
111 FuncForParam->getDescribedFunctionTemplate();
118 const TemplateParameterList *Params = FuncTemplate->getTemplateParameters();
119 if (!std::count(Params->begin(), Params->end(), TypeParmDecl))
122 auto Diag = diag(CallMove->getExprLoc(),
123 "forwarding reference passed to std::move(), which may " 124 "unexpectedly cause lvalues to be moved; use " 125 "std::forward() instead");
static void replaceMoveWithForward(const UnresolvedLookupExpr *Callee, const ParmVarDecl *ParmVar, const TemplateTypeParmDecl *TypeParmDecl, DiagnosticBuilder &Diag, const ASTContext &Context)