Author: sepavloff Date: Thu Jun 9 23:39:07 2016 New Revision: 272366 URL: http://llvm.org/viewvc/llvm-project?rev=272366&view=rev Log: Fix recognition of shadowed template parameter
Crash reported in PR28023 is caused by the fact that non-type template parameters are found by tag name lookup. In the code provided in that PR: template<int V> struct A { struct B { template <int> friend struct V; }; }; the template parameter V is found when lookup for redeclarations of 'struct V' is made. Latter on the error about shadowing of 'V' is emitted but the semantic context of 'struct V' is already determined wrong: 'struct A' instead of translation unit. The fix moves the check for shadowing toward the beginning of the method and thus prevents from wrong context calculations. This change fixes PR28023. Modified: cfe/trunk/lib/Sema/SemaTemplate.cpp cfe/trunk/test/CXX/temp/temp.res/temp.local/p6.cpp Modified: cfe/trunk/lib/Sema/SemaTemplate.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaTemplate.cpp?rev=272366&r1=272365&r2=272366&view=diff ============================================================================== --- cfe/trunk/lib/Sema/SemaTemplate.cpp (original) +++ cfe/trunk/lib/Sema/SemaTemplate.cpp Thu Jun 9 23:39:07 2016 @@ -929,6 +929,13 @@ Sema::CheckClassTemplate(Scope *S, unsig if (Previous.begin() != Previous.end()) PrevDecl = (*Previous.begin())->getUnderlyingDecl(); + if (PrevDecl && PrevDecl->isTemplateParameter()) { + // Maybe we will complain about the shadowed template parameter. + DiagnoseTemplateParameterShadow(NameLoc, PrevDecl); + // Just pretend that we didn't see the previous declaration. + PrevDecl = nullptr; + } + // If there is a previous declaration with the same name, check // whether this is a valid redeclaration. ClassTemplateDecl *PrevClassTemplate @@ -1054,12 +1061,7 @@ Sema::CheckClassTemplate(Scope *S, unsig // definition, as part of error recovery? return true; } - } - } else if (PrevDecl && PrevDecl->isTemplateParameter()) { - // Maybe we will complain about the shadowed template parameter. - DiagnoseTemplateParameterShadow(NameLoc, PrevDecl); - // Just pretend that we didn't see the previous declaration. - PrevDecl = nullptr; + } } else if (PrevDecl) { // C++ [temp]p5: // A class template shall not have the same name as any other Modified: cfe/trunk/test/CXX/temp/temp.res/temp.local/p6.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/temp/temp.res/temp.local/p6.cpp?rev=272366&r1=272365&r2=272366&view=diff ============================================================================== --- cfe/trunk/test/CXX/temp/temp.res/temp.local/p6.cpp (original) +++ cfe/trunk/test/CXX/temp/temp.res/temp.local/p6.cpp Thu Jun 9 23:39:07 2016 @@ -5,11 +5,11 @@ namespace N {} template<typename T, // expected-note {{declared here}} typename T> struct X {}; // expected-error {{declaration of 'T' shadows template parameter}} -template<typename T> struct Y { // expected-note 17{{declared here}} +template<typename T> struct Y { // expected-note 18{{declared here}} template<typename T> struct A {}; // expected-error {{declaration of 'T' shadows template parameter}} struct B { - template<typename> struct T {}; // FIXME: desired-error {{declaration of 'T' shadows template parameter}} + template<typename> struct T {}; // expected-error {{declaration of 'T' shadows template parameter}} }; struct C { template<typename> void T(); // expected-error {{declaration of 'T' shadows template parameter}} @@ -65,11 +65,11 @@ template<typename T> struct Y { // expec friend struct T; // expected-error {{declaration of 'T' shadows template parameter}} }; -template<int T> struct Z { // expected-note 15{{declared here}} +template<int T> struct Z { // expected-note 16{{declared here}} template<typename T> struct A {}; // expected-error {{declaration of 'T' shadows template parameter}} struct B { - template<typename> struct T {}; // FIXME: desired-error {{declaration of 'T' shadows template parameter}} + template<typename> struct T {}; // expected-error {{declaration of 'T' shadows template parameter}} }; struct C { template<typename> void T(); // expected-error {{declaration of 'T' shadows template parameter}} @@ -129,7 +129,8 @@ void f(int T) {} // expected-error {{dec // FIXME: These are ill-formed: a template-parameter shall not have the same name as the template name. namespace A { - template<typename T> struct T {}; + template<typename T> struct T {}; // expected-error{{declaration of 'T' shadows template parameter}} + // expected-note@-1{{template parameter is declared here}} } namespace B { template<typename T> void T() {} @@ -137,3 +138,13 @@ namespace B { namespace C { template<typename T> int T; } + +namespace PR28023 { +template<int V> // expected-note{{template parameter is declared here}} +struct A { + struct B { + template <int> friend struct V; // expected-error{{declaration of 'V' shadows template parameter}} + }; +}; +A<0>::B a; +} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits