Author: rnk Date: Thu Sep 12 11:26:34 2019 New Revision: 371753 URL: http://llvm.org/viewvc/llvm-project?rev=371753&view=rev Log: [MS] Warn when shadowing template parameters under -fms-compatibility
Summary: C++ does not allow shadowing template parameters, but previously we allowed it under -fms-extensions. Now this behavior is controlled by -fms-compatibility, and we emit a -Wmicrosoft-template warning when it happens. Fixes PR43265 Reviewers: thakis, hans Subscribers: amccarth, rsmith, STL_MSFT, cfe-commits Tags: #clang Differential Revision: https://reviews.llvm.org/D67463 Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td cfe/trunk/lib/Sema/SemaTemplate.cpp cfe/trunk/test/Parser/DelayedTemplateParsing.cpp cfe/trunk/test/SemaCXX/MicrosoftCompatibility.cpp Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=371753&r1=371752&r2=371753&view=diff ============================================================================== --- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original) +++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Thu Sep 12 11:26:34 2019 @@ -4000,6 +4000,8 @@ def err_ovl_no_viable_literal_operator : // C++ Template Declarations def err_template_param_shadow : Error< "declaration of %0 shadows template parameter">; +def ext_template_param_shadow : ExtWarn< + err_template_param_shadow.Text>, InGroup<MicrosoftTemplate>; def note_template_param_here : Note<"template parameter is declared here">; def warn_template_export_unsupported : Warning< "exported templates are unsupported">; Modified: cfe/trunk/lib/Sema/SemaTemplate.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaTemplate.cpp?rev=371753&r1=371752&r2=371753&view=diff ============================================================================== --- cfe/trunk/lib/Sema/SemaTemplate.cpp (original) +++ cfe/trunk/lib/Sema/SemaTemplate.cpp Thu Sep 12 11:26:34 2019 @@ -849,15 +849,14 @@ bool Sema::DiagnoseUninstantiableTemplat void Sema::DiagnoseTemplateParameterShadow(SourceLocation Loc, Decl *PrevDecl) { assert(PrevDecl->isTemplateParameter() && "Not a template parameter"); - // Microsoft Visual C++ permits template parameters to be shadowed. - if (getLangOpts().MicrosoftExt) - return; - // C++ [temp.local]p4: // A template-parameter shall not be redeclared within its // scope (including nested scopes). - Diag(Loc, diag::err_template_param_shadow) - << cast<NamedDecl>(PrevDecl)->getDeclName(); + // + // Make this a warning when MSVC compatibility is requested. + unsigned DiagId = getLangOpts().MSVCCompat ? diag::ext_template_param_shadow + : diag::err_template_param_shadow; + Diag(Loc, DiagId) << cast<NamedDecl>(PrevDecl)->getDeclName(); Diag(PrevDecl->getLocation(), diag::note_template_param_here); } Modified: cfe/trunk/test/Parser/DelayedTemplateParsing.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Parser/DelayedTemplateParsing.cpp?rev=371753&r1=371752&r2=371753&view=diff ============================================================================== --- cfe/trunk/test/Parser/DelayedTemplateParsing.cpp (original) +++ cfe/trunk/test/Parser/DelayedTemplateParsing.cpp Thu Sep 12 11:26:34 2019 @@ -48,22 +48,6 @@ template <class T> void foo5() {} // exp -namespace Inner_Outer_same_template_param_name { - -template <class T> -class Outmost { -public: - template <class T> - class Inner { - public: - void f() { - T* var; - } - }; -}; - -} - namespace PR11931 { Modified: cfe/trunk/test/SemaCXX/MicrosoftCompatibility.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/MicrosoftCompatibility.cpp?rev=371753&r1=371752&r2=371753&view=diff ============================================================================== --- cfe/trunk/test/SemaCXX/MicrosoftCompatibility.cpp (original) +++ cfe/trunk/test/SemaCXX/MicrosoftCompatibility.cpp Thu Sep 12 11:26:34 2019 @@ -366,3 +366,21 @@ struct S { int S::fn() { return 0; } // expected-warning {{is missing exception specification}} } +namespace PR43265 { +template <int N> // expected-note {{template parameter is declared here}} +struct Foo { + static const int N = 42; // expected-warning {{declaration of 'N' shadows template parameter}} +}; +} + +namespace Inner_Outer_same_template_param_name { +template <typename T> // expected-note {{template parameter is declared here}} +struct Outmost { + template <typename T> // expected-warning {{declaration of 'T' shadows template parameter}} + struct Inner { + void f() { + T *var; + } + }; +}; +} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
