Implement support for template template parameter packs, e.g.,
template<template<class> class ...Metafunctions>
struct apply_to_each;
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@122874 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
index 419f59d..a0c89f0 100644
--- a/lib/Sema/SemaTemplate.cpp
+++ b/lib/Sema/SemaTemplate.cpp
@@ -522,6 +522,14 @@
IdResolver.AddDecl(Param);
}
+ // C++0x [temp.param]p9:
+ // A default template-argument may be specified for any kind of
+ // template-parameter that is not a template parameter pack.
+ if (DefaultArg && Ellipsis) {
+ Diag(EqualLoc, diag::err_template_param_pack_default_arg);
+ DefaultArg = ParsedType();
+ }
+
// Handle the default argument, if provided.
if (DefaultArg) {
TypeSourceInfo *DefaultTInfo;
@@ -529,14 +537,6 @@
assert(DefaultTInfo && "expected source information for type");
- // C++0x [temp.param]p9:
- // A default template-argument may be specified for any kind of
- // template-parameter that is not a template parameter pack.
- if (Ellipsis) {
- Diag(EqualLoc, diag::err_template_param_pack_default_arg);
- return Param;
- }
-
// Check for unexpanded parameter packs.
if (DiagnoseUnexpandedParameterPack(Loc, DefaultTInfo,
UPPC_DefaultArgument))
@@ -647,16 +647,16 @@
IdResolver.AddDecl(Param);
}
+ // C++0x [temp.param]p9:
+ // A default template-argument may be specified for any kind of
+ // template-parameter that is not a template parameter pack.
+ if (Default && IsParameterPack) {
+ Diag(EqualLoc, diag::err_template_param_pack_default_arg);
+ Default = 0;
+ }
+
// Check the well-formedness of the default template argument, if provided.
if (Default) {
- // C++0x [temp.param]p9:
- // A default template-argument may be specified for any kind of
- // template-parameter that is not a template parameter pack.
- if (IsParameterPack) {
- Diag(EqualLoc, diag::err_template_param_pack_default_arg);
- return Param;
- }
-
// Check for unexpanded parameter packs.
if (DiagnoseUnexpandedParameterPack(Default, UPPC_DefaultArgument))
return Param;
@@ -679,21 +679,24 @@
Decl *Sema::ActOnTemplateTemplateParameter(Scope* S,
SourceLocation TmpLoc,
TemplateParamsTy *Params,
+ SourceLocation EllipsisLoc,
IdentifierInfo *Name,
SourceLocation NameLoc,
unsigned Depth,
unsigned Position,
SourceLocation EqualLoc,
- const ParsedTemplateArgument &Default) {
+ ParsedTemplateArgument Default) {
assert(S->isTemplateParamScope() &&
"Template template parameter not in template parameter scope!");
// Construct the parameter object.
+ bool IsParameterPack = EllipsisLoc.isValid();
+ // FIXME: Pack-ness is dropped
TemplateTemplateParmDecl *Param =
TemplateTemplateParmDecl::Create(Context, Context.getTranslationUnitDecl(),
NameLoc.isInvalid()? TmpLoc : NameLoc,
- Depth, Position, Name,
- Params);
+ Depth, Position, IsParameterPack,
+ Name, Params);
// If the template template parameter has a name, then link the identifier
// into the scope and lookup mechanisms.
@@ -708,6 +711,14 @@
Param->setInvalidDecl();
}
+ // C++0x [temp.param]p9:
+ // A default template-argument may be specified for any kind of
+ // template-parameter that is not a template parameter pack.
+ if (IsParameterPack && !Default.isInvalid()) {
+ Diag(EqualLoc, diag::err_template_param_pack_default_arg);
+ Default = ParsedTemplateArgument();
+ }
+
if (!Default.isInvalid()) {
// Check only that we have a template template argument. We don't want to
// try to check well-formedness now, because our template template parameter
@@ -1212,7 +1223,7 @@
// new declaration.
SawDefaultArgument = true;
// FIXME: We need to create a new kind of "default argument"
- // expression that points to a previous template template
+ // expression that points to a previous non-type template
// parameter.
NewNonTypeParm->setDefaultArgument(
OldNonTypeParm->getDefaultArgument(),
diff --git a/lib/Sema/SemaTemplateInstantiate.cpp b/lib/Sema/SemaTemplateInstantiate.cpp
index 5d724f3..a256537 100644
--- a/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/lib/Sema/SemaTemplateInstantiate.cpp
@@ -697,9 +697,22 @@
TTP->getPosition()))
return D;
- // FIXME: Variadic templates index substitution.
- TemplateName Template
- = TemplateArgs(TTP->getDepth(), TTP->getPosition()).getAsTemplate();
+ TemplateArgument Arg = TemplateArgs(TTP->getDepth(), TTP->getPosition());
+
+ if (TTP->isParameterPack()) {
+ assert(Arg.getKind() == TemplateArgument::Pack &&
+ "Missing argument pack");
+
+ if (getSema().ArgumentPackSubstitutionIndex == -1) {
+ // FIXME: Variadic templates fun case.
+ getSema().Diag(Loc, diag::err_pack_expansion_mismatch_unsupported);
+ return 0;
+ }
+
+ Arg = Arg.pack_begin()[getSema().ArgumentPackSubstitutionIndex];
+ }
+
+ TemplateName Template = Arg.getAsTemplate();
assert(!Template.isNull() && Template.getAsTemplateDecl() &&
"Wrong kind of template template argument");
return Template.getAsTemplateDecl();
diff --git a/lib/Sema/SemaTemplateInstantiateDecl.cpp b/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 60a942a..92521ae 100644
--- a/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -1542,8 +1542,8 @@
TemplateTemplateParmDecl *Param
= TemplateTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
D->getDepth() - TemplateArgs.getNumLevels(),
- D->getPosition(), D->getIdentifier(),
- InstParams);
+ D->getPosition(), D->isParameterPack(),
+ D->getIdentifier(), InstParams);
Param->setDefaultArgument(D->getDefaultArgument(), false);
// Introduce this template parameter's instantiation into the instantiation
diff --git a/lib/Sema/SemaTemplateVariadic.cpp b/lib/Sema/SemaTemplateVariadic.cpp
index 4e01ec2..acb7314 100644
--- a/lib/Sema/SemaTemplateVariadic.cpp
+++ b/lib/Sema/SemaTemplateVariadic.cpp
@@ -78,7 +78,16 @@
return true;
}
- // FIXME: Record occurrences of template template parameter packs.
+ /// \brief Record occurrences of template template parameter packs.
+ bool TraverseTemplateName(TemplateName Template) {
+ if (TemplateTemplateParmDecl *TTP
+ = dyn_cast_or_null<TemplateTemplateParmDecl>(
+ Template.getAsTemplateDecl()))
+ if (TTP->isParameterPack())
+ Unexpanded.push_back(std::make_pair(TTP, SourceLocation()));
+
+ return inherited::TraverseTemplateName(Template);
+ }
//------------------------------------------------------------------------
// Pruning the search for unexpanded parameter packs.
@@ -556,7 +565,6 @@
SourceLocation RParenLoc) {
// C++0x [expr.sizeof]p5:
// The identifier in a sizeof... expression shall name a parameter pack.
-
LookupResult R(*this, &Name, NameLoc, LookupOrdinaryName);
LookupName(R, S);