From 0e97d13b38a758e532850f7ec154befe6032d974 Mon Sep 17 00:00:00 2001 From: Benjamin Kramer Date: Fri, 27 Mar 2015 13:58:31 +0000 Subject: [PATCH] [Sema] Diagnose default argument on a parameter pack. This is ill-formed (and cannot be used anyways). PR23028. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@233376 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/clang/Basic/DiagnosticSemaKinds.td | 2 ++ lib/Sema/SemaDeclCXX.cpp | 13 +++++++++++-- .../CXX/dcl.decl/dcl.meaning/dcl.fct.default/p3.cpp | 3 +++ 3 files changed, 16 insertions(+), 2 deletions(-) diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td index 388069f848..9fa66db139 100644 --- a/include/clang/Basic/DiagnosticSemaKinds.td +++ b/include/clang/Basic/DiagnosticSemaKinds.td @@ -2808,6 +2808,8 @@ def err_param_default_argument_member_template_redecl : Error< "default arguments cannot be added to an out-of-line definition of a member " "of a %select{class template|class template partial specialization|nested " "class in a template}0">; +def err_param_default_argument_on_parameter_pack : Error< + "parameter pack cannot have a default argument">; def err_uninitialized_member_for_assign : Error< "cannot define the implicit copy assignment operator for %0, because " "non-static %select{reference|const}1 member %2 can't use copy " diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp index f7183bc2c4..bb7ba943c6 100644 --- a/lib/Sema/SemaDeclCXX.cpp +++ b/lib/Sema/SemaDeclCXX.cpp @@ -316,8 +316,17 @@ Sema::ActOnParamDefaultArgument(Decl *param, SourceLocation EqualLoc, if (DiagnoseUnexpandedParameterPack(DefaultArg, UPPC_DefaultArgument)) { Param->setInvalidDecl(); return; - } - + } + + // C++11 [dcl.fct.default]p3 + // A default argument expression [...] shall not be specified for a + // parameter pack. + if (Param->isParameterPack()) { + Diag(EqualLoc, diag::err_param_default_argument_on_parameter_pack) + << DefaultArg->getSourceRange(); + return; + } + // Check that the default argument is well-formed CheckDefaultArgumentVisitor DefaultArgChecker(DefaultArg, this); if (DefaultArgChecker.Visit(DefaultArg)) { diff --git a/test/CXX/dcl.decl/dcl.meaning/dcl.fct.default/p3.cpp b/test/CXX/dcl.decl/dcl.meaning/dcl.fct.default/p3.cpp index e03c2164ba..11c17f3272 100644 --- a/test/CXX/dcl.decl/dcl.meaning/dcl.fct.default/p3.cpp +++ b/test/CXX/dcl.decl/dcl.meaning/dcl.fct.default/p3.cpp @@ -14,3 +14,6 @@ struct X0 { void mem8(int (*fp)(int) = (int (*)(int = 17))0); // expected-error{{default arguments can only be specified for parameters in a function declaration}} }; + +template +void defaultpack(Ts... = 0) {} // expected-error{{parameter pack cannot have a default argument}} -- 2.40.0