6550 static void checkDLLAttributeRedeclaration(Sema &S, NamedDecl *OldDecl,  in checkDLLAttributeRedeclaration()  argument
6554   if (OldDecl->isInvalidDecl() || NewDecl->isInvalidDecl())  in checkDLLAttributeRedeclaration()
6558   if (TemplateDecl *OldTD = dyn_cast<TemplateDecl>(OldDecl)) {  in checkDLLAttributeRedeclaration()
6559     OldDecl = OldTD->getTemplatedDecl();  in checkDLLAttributeRedeclaration()
6569   if (!OldDecl || !NewDecl)  in checkDLLAttributeRedeclaration()
6572   const DLLImportAttr *OldImportAttr = OldDecl->getAttr<DLLImportAttr>();  in checkDLLAttributeRedeclaration()
6573   const DLLExportAttr *OldExportAttr = OldDecl->getAttr<DLLExportAttr>();  in checkDLLAttributeRedeclaration()
6588   if (AddsAttr && !IsSpecialization && !OldDecl->isImplicit()) {  in checkDLLAttributeRedeclaration()
6591     if (!OldDecl->isCXXClassMember()) {  in checkDLLAttributeRedeclaration()
6592       auto *VD = dyn_cast<VarDecl>(OldDecl);  in checkDLLAttributeRedeclaration()
6595       auto *FD = dyn_cast<FunctionDecl>(OldDecl);  in checkDLLAttributeRedeclaration()
6603     if (OldDecl->isUsed())  in checkDLLAttributeRedeclaration()
6604       if (!isa<FunctionDecl>(OldDecl) || !NewImportAttr)  in checkDLLAttributeRedeclaration()
6612     S.Diag(OldDecl->getLocation(), diag::note_previous_declaration);  in checkDLLAttributeRedeclaration()
6645       S.Diag(OldDecl->getLocation(), diag::note_previous_declaration);  in checkDLLAttributeRedeclaration()
6653       S.Diag(OldDecl->getLocation(), diag::note_previous_declaration);  in checkDLLAttributeRedeclaration()
6655       OldDecl->dropAttr<DLLImportAttr>();  in checkDLLAttributeRedeclaration()
6661     OldDecl->dropAttr<DLLImportAttr>();  in checkDLLAttributeRedeclaration()
10480     bool &Redeclaration, NamedDecl *&OldDecl, bool &MergeTypeWithPrevious,  in CheckTargetCausesMultiVersioning()  argument
10515     OldDecl = OldFD;  in CheckTargetCausesMultiVersioning()
10554   OldDecl = nullptr;  in CheckTargetCausesMultiVersioning()
10565     bool &Redeclaration, NamedDecl *&OldDecl, bool &MergeTypeWithPrevious,  in CheckMultiVersionAdditionalDecl()  argument
10603         OldDecl = ND;  in CheckMultiVersionAdditionalDecl()
10631           OldDecl = ND;  in CheckMultiVersionAdditionalDecl()
10652           OldDecl = ND;  in CheckMultiVersionAdditionalDecl()
10694     OldDecl = OldFD;  in CheckMultiVersionAdditionalDecl()
10701   OldDecl = nullptr;  in CheckMultiVersionAdditionalDecl()
10714                                       bool &Redeclaration, NamedDecl *&OldDecl,  in CheckMultiVersionFunction()  argument
10744   if (!OldDecl || !OldDecl->getAsFunction() ||  in CheckMultiVersionFunction()
10745       OldDecl->getDeclContext()->getRedeclContext() !=  in CheckMultiVersionFunction()
10754   FunctionDecl *OldFD = OldDecl->getAsFunction();  in CheckMultiVersionFunction()
10769                                             Redeclaration, OldDecl,  in CheckMultiVersionFunction()
10777       OldDecl, MergeTypeWithPrevious, Previous);  in CheckMultiVersionFunction()
10810   NamedDecl *OldDecl = nullptr;  in CheckFunctionDeclaration()  local
10824         OldDecl = Candidate;  in CheckFunctionDeclaration()
10828       switch (CheckOverload(S, NewFD, Previous, OldDecl,  in CheckFunctionDeclaration()
10852       OldDecl = Previous.getFoundDecl();  in CheckFunctionDeclaration()
10856       if (OldDecl->hasAttr<OverloadableAttr>() ||  in CheckFunctionDeclaration()
10858         if (IsOverload(NewFD, cast<FunctionDecl>(OldDecl), false)) {  in CheckFunctionDeclaration()
10861           OldDecl = nullptr;  in CheckFunctionDeclaration()
10867   if (CheckMultiVersionFunction(*this, NewFD, Redeclaration, OldDecl,  in CheckFunctionDeclaration()
10891     if (OldDecl)  in CheckFunctionDeclaration()
10892       OldMD = dyn_cast_or_null<CXXMethodDecl>(OldDecl->getAsFunction());  in CheckFunctionDeclaration()
10918     if (MergeFunctionDecl(NewFD, OldDecl, S, MergeTypeWithPrevious)) {  in CheckFunctionDeclaration()
10924     Previous.addDecl(OldDecl);  in CheckFunctionDeclaration()
10927             dyn_cast<FunctionTemplateDecl>(OldDecl)) {  in CheckFunctionDeclaration()
10961       if (shouldLinkDependentDeclWithPrevious(NewFD, OldDecl)) {  in CheckFunctionDeclaration()
10962         auto *OldFD = cast<FunctionDecl>(OldDecl);  in CheckFunctionDeclaration()