/// ParseTemplateArgumentList - Parse a C++ template-argument-list
/// (C++ [temp.names]). Returns true if there was an error.
///
/// template-argument-list: [C++ 14.2]
/// template-argument
/// template-argument-list ',' template-argument
bool
Parser::ParseTemplateArgumentList(TemplateArgList &TemplateArgs) {
while (true) {
ParsedTemplateArgument Arg = ParseTemplateArgument();
if (Tok.is(tok::ellipsis)) {
SourceLocation EllipsisLoc = ConsumeToken();
Arg = Actions.ActOnPackExpansion(Arg, EllipsisLoc);
}
if (Arg.isInvalid()) {
SkipUntil(tok::comma, tok::greater, true, true);
return true;
}
// Save this template argument.
TemplateArgs.push_back(Arg);
// If the next token is a comma, consume it and keep reading
// arguments.
if (Tok.isNot(tok::comma)) break;
// Consume the comma.
ConsumeToken();
}
return false;
}
/// ParseTemplateArgument - Parse a C++ template argument (C++ [temp.names]).
///
/// template-argument: [C++ 14.2]
/// constant-expression
/// type-id
/// id-expression
ParsedTemplateArgument Parser::ParseTemplateArgument() {
// C++ [temp.arg]p2:
// In a template-argument, an ambiguity between a type-id and an
// expression is resolved to a type-id, regardless of the form of
// the corresponding template-parameter.
//
// Therefore, we initially try to parse a type-id.
if (isCXXTypeId(TypeIdAsTemplateArgument)) {
SourceLocation Loc = Tok.getLocation();
TypeResult TypeArg = ParseTypeName(/*Range=*/0,
Declarator::TemplateTypeArgContext);
if (TypeArg.isInvalid())
return ParsedTemplateArgument();
return ParsedTemplateArgument(ParsedTemplateArgument::Type,
TypeArg.get().getAsOpaquePtr(),
Loc);
}
// Try to parse a template template argument.
{
TentativeParsingAction TPA(*this);
ParsedTemplateArgument TemplateTemplateArgument
= ParseTemplateTemplateArgument();
if (!TemplateTemplateArgument.isInvalid()) {
TPA.Commit();
return TemplateTemplateArgument;
}
// Revert this tentative parse to parse a non-type template argument.
TPA.Revert();
}
// Parse a non-type template argument.
SourceLocation Loc = Tok.getLocation();
ExprResult ExprArg = ParseConstantExpression();
if (ExprArg.isInvalid() || !ExprArg.get())
return ParsedTemplateArgument();
return ParsedTemplateArgument(ParsedTemplateArgument::NonType,
ExprArg.release(), Loc);
}
ParsedTemplateArgument
Sema::ActOnPackExpansion(const ParsedTemplateArgument &Arg,
SourceLocation EllipsisLoc) {
if (Arg.isInvalid())
return Arg;
switch (Arg.getKind()) {
case ParsedTemplateArgument::Type: {
TypeResult Result = ActOnPackExpansion(Arg.getAsType(), EllipsisLoc);
if (Result.isInvalid())
return ParsedTemplateArgument();
return ParsedTemplateArgument(Arg.getKind(), Result.get().getAsOpaquePtr(),
Arg.getLocation());
}
case ParsedTemplateArgument::NonType: {
ExprResult Result = ActOnPackExpansion(Arg.getAsExpr(), EllipsisLoc);
if (Result.isInvalid())
return ParsedTemplateArgument();
return ParsedTemplateArgument(Arg.getKind(), Result.get(),
Arg.getLocation());
}
case ParsedTemplateArgument::Template:
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?");
}
/// \brief Parse a C++ template template argument.
ParsedTemplateArgument Parser::ParseTemplateTemplateArgument() {
if (!Tok.is(tok::identifier) && !Tok.is(tok::coloncolon) &&
!Tok.is(tok::annot_cxxscope))
return ParsedTemplateArgument();
// C++0x [temp.arg.template]p1:
// A template-argument for a template template-parameter shall be the name
// of a class template or a template alias, expressed as id-expression.
//
// We parse an id-expression that refers to a class template or template
// alias. The grammar we parse is:
//
// nested-name-specifier[opt] template[opt] identifier ...[opt]
//
// followed by a token that terminates a template argument, such as ',',
// '>', or (in some cases) '>>'.
CXXScopeSpec SS; // nested-name-specifier, if present
ParseOptionalCXXScopeSpecifier(SS, ParsedType(),
/*EnteringContext=*/false);
ParsedTemplateArgument Result;
SourceLocation EllipsisLoc;
if (SS.isSet() && Tok.is(tok::kw_template)) {
// Parse the optional 'template' keyword following the
// nested-name-specifier.
SourceLocation TemplateLoc = ConsumeToken();
if (Tok.is(tok::identifier)) {
// We appear to have a dependent template name.
UnqualifiedId Name;
Name.setIdentifier(Tok.getIdentifierInfo(), Tok.getLocation());
ConsumeToken(); // the identifier
// Parse the ellipsis.
if (Tok.is(tok::ellipsis))
EllipsisLoc = ConsumeToken();
// If the next token signals the end of a template argument,
// then we have a dependent template name that could be a template
// template argument.
TemplateTy Template;
if (isEndOfTemplateArgument(Tok) &&
Actions.ActOnDependentTemplateName(getCurScope(), TemplateLoc,
SS, Name,
/*ObjectType=*/ ParsedType(),
/*EnteringContext=*/false,
Template))
Result = ParsedTemplateArgument(SS, Template, Name.StartLocation);
}
} else if (Tok.is(tok::identifier)) {
// We may have a (non-dependent) template name.
TemplateTy Template;
UnqualifiedId Name;
Name.setIdentifier(Tok.getIdentifierInfo(), Tok.getLocation());
ConsumeToken(); // the identifier
// Parse the ellipsis.
if (Tok.is(tok::ellipsis))
EllipsisLoc = ConsumeToken();
if (isEndOfTemplateArgument(Tok)) {
bool MemberOfUnknownSpecialization;
TemplateNameKind TNK = Actions.isTemplateName(getCurScope(), SS,
/*hasTemplateKeyword=*/false,
Name,
/*ObjectType=*/ ParsedType(),
/*EnteringContext=*/false,
Template,
MemberOfUnknownSpecialization);
if (TNK == TNK_Dependent_template_name || TNK == TNK_Type_template) {
// We have an id-expression that refers to a class template or
// (C++0x) template alias.
Result = ParsedTemplateArgument(SS, Template, Name.StartLocation);
}
}
}
// If this is a pack expansion, build it as such.
if (EllipsisLoc.isValid() && !Result.isInvalid())
Result = Actions.ActOnPackExpansion(Result, EllipsisLoc);
return Result;
}
/// ParseTemplateTemplateParameter - Handle the parsing of template
/// template parameters.
///
/// type-parameter: [C++ temp.param]
/// 'template' '<' template-parameter-list '>' 'class'
/// ...[opt] identifier[opt]
/// 'template' '<' template-parameter-list '>' 'class' identifier[opt]
/// = id-expression
Decl *
Parser::ParseTemplateTemplateParameter(unsigned Depth, unsigned Position) {
assert(Tok.is(tok::kw_template) && "Expected 'template' keyword");
// Handle the template <...> part.
SourceLocation TemplateLoc = ConsumeToken();
llvm::SmallVector<Decl*,8> TemplateParams;
SourceLocation LAngleLoc, RAngleLoc;
{
ParseScope TemplateParmScope(this, Scope::TemplateParamScope);
if (ParseTemplateParameters(Depth + 1, TemplateParams, LAngleLoc,
RAngleLoc)) {
return 0;
}
}
// Generate a meaningful error if the user forgot to put class before the
// identifier, comma, or greater.
if (!Tok.is(tok::kw_class)) {
Diag(Tok.getLocation(), diag::err_expected_class_before)
<< PP.getSpelling(Tok);
return 0;
}
ConsumeToken();
// Parse the ellipsis, if given.
SourceLocation EllipsisLoc;
if (Tok.is(tok::ellipsis)) {
EllipsisLoc = ConsumeToken();
if (!getLang().CPlusPlus0x)
Diag(EllipsisLoc, diag::ext_variadic_templates);
}
// Get the identifier, if given.
SourceLocation NameLoc;
IdentifierInfo* ParamName = 0;
if (Tok.is(tok::identifier)) {
ParamName = Tok.getIdentifierInfo();
NameLoc = ConsumeToken();
} else if (Tok.is(tok::equal) || Tok.is(tok::comma) || Tok.is(tok::greater)) {
// Unnamed template parameter. Don't have to do anything here, just
// don't consume this token.
} else {
Diag(Tok.getLocation(), diag::err_expected_ident);
return 0;
}
TemplateParamsTy *ParamList =
Actions.ActOnTemplateParameterList(Depth, SourceLocation(),
TemplateLoc, LAngleLoc,
TemplateParams.data(),
TemplateParams.size(),
RAngleLoc);
// Grab a default argument (if available).
// Per C++0x [basic.scope.pdecl]p9, we parse the default argument before
// we introduce the template parameter into the local scope.
SourceLocation EqualLoc;
ParsedTemplateArgument DefaultArg;
if (Tok.is(tok::equal)) {
EqualLoc = ConsumeToken();
DefaultArg = ParseTemplateTemplateArgument();
if (DefaultArg.isInvalid()) {
Diag(Tok.getLocation(),
diag::err_default_template_template_parameter_not_template);
static const tok::TokenKind EndToks[] = {
tok::comma, tok::greater, tok::greatergreater
};
SkipUntil(EndToks, 3, true, true);
}
}
return Actions.ActOnTemplateTemplateParameter(getCurScope(), TemplateLoc,
ParamList, EllipsisLoc,
ParamName, NameLoc, Depth,
Position, EqualLoc, DefaultArg);
}
/// ParseTemplateTemplateParameter - Handle the parsing of template
/// template parameters.
///
/// type-parameter: [C++ temp.param]
/// 'template' '<' template-parameter-list '>' 'class'
/// ...[opt] identifier[opt]
/// 'template' '<' template-parameter-list '>' 'class' identifier[opt]
/// = id-expression
Decl *
Parser::ParseTemplateTemplateParameter(unsigned Depth, unsigned Position) {
assert(Tok.is(tok::kw_template) && "Expected 'template' keyword");
// Handle the template <...> part.
SourceLocation TemplateLoc = ConsumeToken();
SmallVector<Decl*,8> TemplateParams;
SourceLocation LAngleLoc, RAngleLoc;
{
ParseScope TemplateParmScope(this, Scope::TemplateParamScope);
if (ParseTemplateParameters(Depth + 1, TemplateParams, LAngleLoc,
RAngleLoc)) {
return 0;
}
}
// Generate a meaningful error if the user forgot to put class before the
// identifier, comma, or greater. Provide a fixit if the identifier, comma,
// or greater appear immediately or after 'typename' or 'struct'. In the
// latter case, replace the keyword with 'class'.
if (!Tok.is(tok::kw_class)) {
bool Replace = Tok.is(tok::kw_typename) || Tok.is(tok::kw_struct);
const Token& Next = Replace ? NextToken() : Tok;
if (Next.is(tok::identifier) || Next.is(tok::comma) ||
Next.is(tok::greater) || Next.is(tok::greatergreater) ||
Next.is(tok::ellipsis))
Diag(Tok.getLocation(), diag::err_class_on_template_template_param)
<< (Replace ? FixItHint::CreateReplacement(Tok.getLocation(), "class")
: FixItHint::CreateInsertion(Tok.getLocation(), "class "));
else
Diag(Tok.getLocation(), diag::err_class_on_template_template_param);
if (Replace)
ConsumeToken();
} else
ConsumeToken();
// Parse the ellipsis, if given.
SourceLocation EllipsisLoc;
if (Tok.is(tok::ellipsis)) {
EllipsisLoc = ConsumeToken();
Diag(EllipsisLoc,
getLangOpts().CPlusPlus0x
? diag::warn_cxx98_compat_variadic_templates
: diag::ext_variadic_templates);
}
// Get the identifier, if given.
SourceLocation NameLoc;
IdentifierInfo* ParamName = 0;
if (Tok.is(tok::identifier)) {
ParamName = Tok.getIdentifierInfo();
NameLoc = ConsumeToken();
} else if (Tok.is(tok::equal) || Tok.is(tok::comma) ||
Tok.is(tok::greater) || Tok.is(tok::greatergreater)) {
// Unnamed template parameter. Don't have to do anything here, just
// don't consume this token.
} else {
Diag(Tok.getLocation(), diag::err_expected_ident);
return 0;
}
TemplateParameterList *ParamList =
Actions.ActOnTemplateParameterList(Depth, SourceLocation(),
TemplateLoc, LAngleLoc,
TemplateParams.data(),
TemplateParams.size(),
RAngleLoc);
// Grab a default argument (if available).
// Per C++0x [basic.scope.pdecl]p9, we parse the default argument before
// we introduce the template parameter into the local scope.
SourceLocation EqualLoc;
ParsedTemplateArgument DefaultArg;
if (Tok.is(tok::equal)) {
EqualLoc = ConsumeToken();
DefaultArg = ParseTemplateTemplateArgument();
if (DefaultArg.isInvalid()) {
Diag(Tok.getLocation(),
diag::err_default_template_template_parameter_not_template);
SkipUntil(tok::comma, tok::greater, tok::greatergreater, true, true);
}
}
return Actions.ActOnTemplateTemplateParameter(getCurScope(), TemplateLoc,
ParamList, EllipsisLoc,
ParamName, NameLoc, Depth,
Position, EqualLoc, DefaultArg);
}
