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Add semantic analysis for the creation of and an AST representation 

for template template argument pack expansions. This allows fun such
as: 

  template<template<class> class ...> struct apply_impl { /*...*/ };
  template<template<class> class ...Metafunctions> struct apply {
    typedef typename apply_impl<Metafunctions...>::type type;
  };

However, neither template argument deduction nor template
instantiation is implemented for template template argument packs, so
this functionality isn't useful yet.

I'll probably replace the encoding of template template
argument pack expansions in TemplateArgument so that it's harder to
accidentally forget about the expansion. However, this is a step in
the right general direction.

llvm-svn: 122890
This commit is contained in:
Douglas Gregor 2011-01-05 17:40:24 +00:00
parent 07fd1efcfa
commit eb29d18e5d
10 changed files with 159 additions and 61 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

47
clang/include/clang/AST/TemplateBase.h
View File

@ -77,6 +77,10 @@ private:
TemplateArgument *Args;
unsigned NumArgs;
} Args;
struct {
void *Template;
bool PackExpansion;
} TemplateArg;
};
public:
@ -104,14 +108,21 @@ public:
Integer.Type = Type.getAsOpaquePtr();
}
/// \brief Construct a template argument that is a template.
/// \brief Construct a template argument that is a template or a pack
/// expansion of templates.
///
/// This form of template argument is generally used for template template
/// parameters. However, the template name could be a dependent template
/// name that ends up being instantiated to a function template whose address
/// is taken.
TemplateArgument(TemplateName Name) : Kind(Template) {
TypeOrValue = reinterpret_cast<uintptr_t>(Name.getAsVoidPointer());
///
/// \param Name The template name.
/// \param PackExpansion Whether this template argument is a pack expansion.
TemplateArgument(TemplateName Name, bool PackExpansion = false)
: Kind(Template)
{
TemplateArg.Template = Name.getAsVoidPointer();
TemplateArg.PackExpansion = PackExpansion;
}
/// \brief Construct a template argument that is an expression.
@ -142,8 +153,9 @@ public:
} else if (Kind == Pack) {
Args.NumArgs = Other.Args.NumArgs;
Args.Args = Other.Args.Args;
}
else
} else if (Kind == Template) {
TemplateArg = Other.TemplateArg;
} else
TypeOrValue = Other.TypeOrValue;
}
@ -169,6 +181,8 @@ public:
} else if (Other.Kind == Pack) {
Args.NumArgs = Other.Args.NumArgs;
Args.Args = Other.Args.Args;
} else if (Other.Kind == Template) {
TemplateArg = Other.TemplateArg;
} else {
TypeOrValue = Other.TypeOrValue;
}
@ -220,8 +234,7 @@ public:
if (Kind != Template)
return TemplateName();
return TemplateName::getFromVoidPointer(
reinterpret_cast<void *> (TypeOrValue));
return TemplateName::getFromVoidPointer(TemplateArg.Template);
}
/// \brief Retrieve the template argument as an integral value.
@ -307,6 +320,7 @@ private:
struct {
unsigned QualifierRange[2];
unsigned TemplateNameLoc;
unsigned EllipsisLoc;
} Template;
};
@ -318,11 +332,13 @@ public:
TemplateArgumentLocInfo(Expr *E) : Expression(E) {}
TemplateArgumentLocInfo(SourceRange QualifierRange,
SourceLocation TemplateNameLoc)
SourceLocation TemplateNameLoc,
SourceLocation EllipsisLoc)
{
Template.QualifierRange[0] = QualifierRange.getBegin().getRawEncoding();
Template.QualifierRange[1] = QualifierRange.getEnd().getRawEncoding();
Template.TemplateNameLoc = TemplateNameLoc.getRawEncoding();
Template.EllipsisLoc = EllipsisLoc.getRawEncoding();
}
TypeSourceInfo *getAsTypeSourceInfo() const {
@ -342,6 +358,10 @@ public:
SourceLocation getTemplateNameLoc() const {
return SourceLocation::getFromRawEncoding(Template.TemplateNameLoc);
}
SourceLocation getTemplateEllipsisLoc() const {
return SourceLocation::getFromRawEncoding(Template.EllipsisLoc);
}
};
/// Location wrapper for a TemplateArgument. TemplateArgument is to
@ -370,8 +390,10 @@ public:
TemplateArgumentLoc(const TemplateArgument &Argument,
SourceRange QualifierRange,
SourceLocation TemplateNameLoc)
: Argument(Argument), LocInfo(QualifierRange, TemplateNameLoc) {
SourceLocation TemplateNameLoc,
SourceLocation EllipsisLoc = SourceLocation())
: Argument(Argument),
LocInfo(QualifierRange, TemplateNameLoc, EllipsisLoc) {
assert(Argument.getKind() == TemplateArgument::Template);
}
@ -419,6 +441,11 @@ public:
return LocInfo.getTemplateNameLoc();
}
SourceLocation getTemplateEllipsisLoc() const {
assert(Argument.getKind() == TemplateArgument::Template);
return LocInfo.getTemplateEllipsisLoc();
}
/// \brief When the template argument is a pack expansion, returns
/// the pattern of the pack expansion.
///

21
clang/include/clang/Sema/ParsedTemplate.h
View File

@ -58,7 +58,7 @@ namespace clang {
SourceLocation TemplateLoc)
: Kind(ParsedTemplateArgument::Template),
Arg(Template.getAsOpaquePtr()),
Loc(TemplateLoc), SS(SS) { }
Loc(TemplateLoc), SS(SS), EllipsisLoc() { }
/// \brief Determine whether the given template argument is invalid.
bool isInvalid() const { return Arg == 0; }
@ -95,6 +95,21 @@ namespace clang {
return SS;
}
/// \brief Retrieve the location of the ellipsis that makes a template
/// template argument into a pack expansion.
SourceLocation getEllipsisLoc() const {
assert(Kind == Template &&
"Only template template arguments can have an ellipsis");
return EllipsisLoc;
}
/// \brief Retrieve a pack expansion of the given template template
/// argument.
///
/// \param EllipsisLoc The location of the ellipsis.
ParsedTemplateArgument getTemplatePackExpansion(
SourceLocation EllipsisLoc) const;
private:
KindType Kind;
@ -109,6 +124,10 @@ namespace clang {
/// \brief The nested-name-specifier that can accompany a template template
/// argument.
CXXScopeSpec SS;
/// \brief The ellipsis location that can accompany a template template
/// argument (turning it into a template template argument expansion).
SourceLocation EllipsisLoc;
};
/// \brief Information about a template-id annotation

3
clang/lib/AST/DeclTemplate.cpp
View File

@ -335,8 +335,7 @@ ClassTemplateDecl::getInjectedClassNameSpecialization() {
Arg = TemplateArgument(E);
} else {
TemplateTemplateParmDecl *TTP = cast<TemplateTemplateParmDecl>(*Param);
// FIXME: Variadic templates.
Arg = TemplateArgument(TemplateName(TTP));
Arg = TemplateArgument(TemplateName(TTP), TTP->isParameterPack());
}
if ((*Param)->isTemplateParameterPack()) {

72
clang/lib/AST/TemplateBase.cpp
View File

@ -76,8 +76,7 @@ bool TemplateArgument::isPackExpansion() const {
return isa<PackExpansionType>(getAsType());
case Template:
// FIXME: Template template pack expansions.
break;
return TemplateArg.PackExpansion;
case Expression:
return isa<PackExpansionExpr>(getAsExpr());
@ -99,7 +98,8 @@ bool TemplateArgument::containsUnexpandedParameterPack() const {
break;
case Template:
if (getAsTemplate().containsUnexpandedParameterPack())
if (!TemplateArg.PackExpansion &&
getAsTemplate().containsUnexpandedParameterPack())
return true;
break;
@ -135,12 +135,14 @@ void TemplateArgument::Profile(llvm::FoldingSetNodeID &ID,
break;
case Template:
ID.AddBoolean(TemplateArg.PackExpansion);
if (TemplateTemplateParmDecl *TTP
= dyn_cast_or_null<TemplateTemplateParmDecl>(
getAsTemplate().getAsTemplateDecl())) {
ID.AddBoolean(true);
ID.AddInteger(TTP->getDepth());
ID.AddInteger(TTP->getPosition());
ID.AddBoolean(TTP->isParameterPack());
} else {
ID.AddBoolean(false);
ID.AddPointer(Context.getCanonicalTemplateName(getAsTemplate())
@ -171,10 +173,13 @@ bool TemplateArgument::structurallyEquals(const TemplateArgument &Other) const {
case Null:
case Type:
case Declaration:
case Template:
case Expression:
return TypeOrValue == Other.TypeOrValue;
case Template:
return TemplateArg.Template == Other.TemplateArg.Template &&
TemplateArg.PackExpansion == Other.TemplateArg.PackExpansion;
case Integral:
return getIntegralType() == Other.getIntegralType() &&
*getAsIntegral() == *Other.getAsIntegral();
@ -195,21 +200,20 @@ TemplateArgument TemplateArgument::getPackExpansionPattern() const {
assert(isPackExpansion());
switch (getKind()) {
case Type:
return getAsType()->getAs<PackExpansionType>()->getPattern();
case Expression:
return cast<PackExpansionExpr>(getAsExpr())->getPattern();
case Template:
// FIXME: Variadic templates.
llvm_unreachable("Template pack expansions unsupported");
case Declaration:
case Integral:
case Pack:
case Null:
return TemplateArgument();
case Type:
return getAsType()->getAs<PackExpansionType>()->getPattern();
case Expression:
return cast<PackExpansionExpr>(getAsExpr())->getPattern();
case Template:
return TemplateArgument(getAsTemplate(), false);
case Declaration:
case Integral:
case Pack:
case Null:
return TemplateArgument();
}
return TemplateArgument();
@ -246,6 +250,8 @@ void TemplateArgument::print(const PrintingPolicy &Policy,
case Template: {
getAsTemplate().print(Out, Policy);
if (TemplateArg.PackExpansion)
Out << "...";
break;
}
@ -254,12 +260,9 @@ void TemplateArgument::print(const PrintingPolicy &Policy,
break;
}
case Expression: {
// FIXME: This is non-optimal, since we're regurgitating the
// expression we were given.
case Expression:
getAsExpr()->printPretty(Out, 0, Policy);
break;
}
case Pack:
Out << "<";
@ -296,12 +299,15 @@ SourceRange TemplateArgumentLoc::getSourceRange() const {
else
return SourceRange();
case TemplateArgument::Template:
case TemplateArgument::Template: {
SourceLocation End = getTemplateNameLoc();
if (getTemplateEllipsisLoc().isValid())
End = getTemplateEllipsisLoc();
if (getTemplateQualifierRange().isValid())
return SourceRange(getTemplateQualifierRange().getBegin(),
getTemplateNameLoc());
return SourceRange(getTemplateNameLoc());
return SourceRange(getTemplateQualifierRange().getBegin(), End);
return SourceRange(getTemplateNameLoc(), End);
}
case TemplateArgument::Integral:
case TemplateArgument::Pack:
case TemplateArgument::Null:
@ -351,8 +357,9 @@ TemplateArgumentLoc::getPackExpansionPattern(SourceLocation &Ellipsis,
}
case TemplateArgument::Template:
// FIXME: Variadic templates.
llvm_unreachable("Template pack expansions unsupported");
return TemplateArgumentLoc(Argument.getPackExpansionPattern(),
getTemplateQualifierRange(),
getTemplateNameLoc());
case TemplateArgument::Declaration:
case TemplateArgument::Integral:
@ -382,7 +389,10 @@ const DiagnosticBuilder &clang::operator<<(const DiagnosticBuilder &DB,
return DB << Arg.getAsIntegral()->toString(10);
case TemplateArgument::Template:
return DB << Arg.getAsTemplate();
DB << Arg.getAsTemplate();
if (Arg.isPackExpansion())
DB << "...";
return DB;
case TemplateArgument::Expression: {
// This shouldn't actually ever happen, so it's okay that we're

17
clang/lib/Sema/SemaTemplate.cpp
View File

@ -437,6 +437,17 @@ TemplateDecl *Sema::AdjustDeclIfTemplate(Decl *&D) {
return 0;
}
ParsedTemplateArgument ParsedTemplateArgument::getTemplatePackExpansion(
SourceLocation EllipsisLoc) const {
assert(Kind == Template &&
"Only template template arguments can be pack expansions here");
assert(getAsTemplate().get().containsUnexpandedParameterPack() &&
"Template template argument pack expansion without packs");
ParsedTemplateArgument Result(*this);
Result.EllipsisLoc = EllipsisLoc;
return Result;
}
static TemplateArgumentLoc translateTemplateArgument(Sema &SemaRef,
const ParsedTemplateArgument &Arg) {
@ -456,9 +467,11 @@ static TemplateArgumentLoc translateTemplateArgument(Sema &SemaRef,
case ParsedTemplateArgument::Template: {
TemplateName Template = Arg.getAsTemplate().get();
return TemplateArgumentLoc(TemplateArgument(Template),
return TemplateArgumentLoc(TemplateArgument(Template,
Arg.getEllipsisLoc().isValid()),
Arg.getScopeSpec().getRange(),
Arg.getLocation());
Arg.getLocation(),
Arg.getEllipsisLoc());
}
}

7
clang/lib/Sema/SemaTemplateDeduction.cpp
View File

@ -1344,19 +1344,20 @@ getTrivialTemplateArgumentLoc(Sema &S,
case TemplateArgument::Declaration: {
Expr *E
= S.BuildExpressionFromDeclTemplateArgument(Arg, NTTPType, Loc)
= S.BuildExpressionFromDeclTemplateArgument(Arg, NTTPType, Loc)
.takeAs<Expr>();
return TemplateArgumentLoc(TemplateArgument(E), E);
}
case TemplateArgument::Integral: {
Expr *E
= S.BuildExpressionFromIntegralTemplateArgument(Arg, Loc).takeAs<Expr>();
= S.BuildExpressionFromIntegralTemplateArgument(Arg, Loc).takeAs<Expr>();
return TemplateArgumentLoc(TemplateArgument(E), E);
}
case TemplateArgument::Template:
return TemplateArgumentLoc(Arg, SourceRange(), Loc);
return TemplateArgumentLoc(Arg, SourceRange(), Loc,
Arg.isPackExpansion()? Loc : SourceLocation());
case TemplateArgument::Expression:
return TemplateArgumentLoc(Arg, Arg.getAsExpr());

28
clang/lib/Sema/SemaTemplateVariadic.cpp
View File

@ -130,6 +130,22 @@ namespace {
return true;
}
/// \brief Suppress traversal of template argument pack expansions.
bool TraverseTemplateArgument(const TemplateArgument &Arg) {
if (Arg.isPackExpansion())
return true;
return inherited::TraverseTemplateArgument(Arg);
}
/// \brief Suppress traversal of template argument pack expansions.
bool TraverseTemplateArgumentLoc(const TemplateArgumentLoc &ArgLoc) {
if (ArgLoc.getArgument().isPackExpansion())
return true;
return inherited::TraverseTemplateArgumentLoc(ArgLoc);
}
};
}
@ -335,8 +351,16 @@ Sema::ActOnPackExpansion(const ParsedTemplateArgument &Arg,
}
case ParsedTemplateArgument::Template:
Diag(EllipsisLoc, diag::err_pack_expansion_unsupported);
return ParsedTemplateArgument();
if (!Arg.getAsTemplate().get().containsUnexpandedParameterPack()) {
SourceRange R(Arg.getLocation());
if (Arg.getScopeSpec().isValid())
R.setBegin(Arg.getScopeSpec().getBeginLoc());
Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
<< R;
return ParsedTemplateArgument();
}
return Arg.getTemplatePackExpansion(EllipsisLoc);
}
llvm_unreachable("Unhandled template argument kind?");
return ParsedTemplateArgument();

11
clang/lib/Serialization/ASTReader.cpp
View File

@ -3381,7 +3381,9 @@ ASTReader::GetTemplateArgumentLocInfo(PerFileData &F,
case TemplateArgument::Template: {
SourceRange QualifierRange = ReadSourceRange(F, Record, Index);
SourceLocation TemplateNameLoc = ReadSourceLocation(F, Record, Index);
return TemplateArgumentLocInfo(QualifierRange, TemplateNameLoc);
SourceLocation EllipsisLoc = ReadSourceLocation(F, Record, Index);
return TemplateArgumentLocInfo(QualifierRange, TemplateNameLoc,
EllipsisLoc);
}
case TemplateArgument::Null:
case TemplateArgument::Integral:
@ -4226,8 +4228,11 @@ ASTReader::ReadTemplateArgument(PerFileData &F,
QualType T = GetType(Record[Idx++]);
return TemplateArgument(Value, T);
}
case TemplateArgument::Template:
return TemplateArgument(ReadTemplateName(Record, Idx));
case TemplateArgument::Template: {
TemplateName Name = ReadTemplateName(Record, Idx);
bool IsPackExpansion = Record[Idx++];
return TemplateArgument(Name, IsPackExpansion);
}
case TemplateArgument::Expression:
return TemplateArgument(ReadExpr(F));
case TemplateArgument::Pack: {

2
clang/lib/Serialization/ASTWriter.cpp
View File

@ -2889,6 +2889,7 @@ void ASTWriter::AddTemplateArgumentLocInfo(TemplateArgument::ArgKind Kind,
case TemplateArgument::Template:
AddSourceRange(Arg.getTemplateQualifierRange(), Record);
AddSourceLocation(Arg.getTemplateNameLoc(), Record);
AddSourceLocation(Arg.getTemplateEllipsisLoc(), Record);
break;
case TemplateArgument::Null:
case TemplateArgument::Integral:
@ -3176,6 +3177,7 @@ void ASTWriter::AddTemplateArgument(const TemplateArgument &Arg,
break;
case TemplateArgument::Template:
AddTemplateName(Arg.getAsTemplate(), Record);
Record.push_back(Arg.isPackExpansion());
break;
case TemplateArgument::Expression:
AddStmt(Arg.getAsExpr());

12
clang/test/CXX/temp/temp.param/p11-0x.cpp
View File

@ -34,10 +34,9 @@ template<typename ...Types, typename T> struct X1t<T, Types...> { };
template<int... Values> struct X1nt;
template<int ...Values, int V> struct X1nt<V, Values...> { };
// FIXME: Need template template argument packs!
// template<template<int> class... Meta> struct X1tt;
// template<template<int> class... Meta, template<int> class M>
// struct X1tt<M, Meta...> { };
template<template<int> class... Meta> struct X1tt;
template<template<int> class... Meta, template<int> class M>
struct X1tt<M, Meta...> { };
template<typename ...Types, typename T>
void f1t(X1t<T, Types...>);
@ -45,6 +44,5 @@ void f1t(X1t<T, Types...>);
template<int ...Values, int V>
void f1nt(X1nt<V, Values...>);
// FIXME: Need template template argument packs!
// template<template<int> class... Meta, template<int> class M>
// void f1tt(X1tt<M, Meta...>);
template<template<int> class... Meta, template<int> class M>
void f1tt(X1tt<M, Meta...>);