From 506bd56484a5969c91a7ea93a04142274d15c0d4 Mon Sep 17 00:00:00 2001 From: Douglas Gregor Date: Mon, 13 Dec 2010 22:49:22 +0000 Subject: Variadic templates: extend Type, NestedNameSpecifier, TemplateName, and TemplateArgument with an operation that determines whether there are any unexpanded parameter packs within that construct. Use this information to diagnose the appearance of the names of parameter packs that have not been expanded (C++ [temp.variadic]p5). Since this property is checked often (every declaration, ever expression statement, etc.), we extend Type and Expr with a bit storing the result of this computation, rather than walking the AST each time to determine whether any unexpanded parameter packs occur. This commit is deficient in several ways, which will be remedied with future commits: - Expr has a bit to store the presence of an unexpanded parameter pack, but it is never set. - The error messages don't point out where the unexpanded parameter packs were named in the type/expression, but they should. - We don't check for unexpanded parameter packs in all of the places where we should. - Testing is sparse, pending the resolution of the above three issues. llvm-svn: 121724 --- clang/lib/Sema/SemaTemplate.cpp | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) (limited to 'clang/lib/Sema/SemaTemplate.cpp') diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp index 53a02a98864..141c41618d8 100644 --- a/clang/lib/Sema/SemaTemplate.cpp +++ b/clang/lib/Sema/SemaTemplate.cpp @@ -5954,3 +5954,33 @@ Sema::getTemplateArgumentBindingsText(const TemplateParameterList *Params, Result += ']'; return Result; } + +bool Sema::DiagnoseUnexpandedParameterPack(SourceLocation Loc, + TypeSourceInfo *T, + UnexpandedParameterPackContext UPPC) { + // C++0x [temp.variadic]p5: + // An appearance of a name of a parameter pack that is not expanded is + // ill-formed. + if (!T->getType()->containsUnexpandedParameterPack()) + return false; + + // FIXME: Provide the names and locations of the unexpanded parameter packs. + Diag(Loc, diag::err_unexpanded_parameter_pack) + << (int)UPPC << T->getTypeLoc().getSourceRange(); + return true; +} + +bool Sema::DiagnoseUnexpandedParameterPack(Expr *E, + UnexpandedParameterPackContext UPPC) { + // C++0x [temp.variadic]p5: + // An appearance of a name of a parameter pack that is not expanded is + // ill-formed. + if (!E->containsUnexpandedParameterPack()) + return false; + + // FIXME: Provide the names and locations of the unexpanded parameter packs. + Diag(E->getSourceRange().getBegin(), diag::err_unexpanded_parameter_pack) + << (int)UPPC << E->getSourceRange(); + return true; +} + -- cgit v1.2.3