[cfe-commits] r149697 - in /cfe/trunk: include/clang/AST/Type.h include/clang/Sema/Sema.h lib/AST/ASTContext.cpp lib/AST/Type.cpp lib/Sema/SemaTemplate.cpp test/CXX/temp/temp.decls/temp.variadic/fixed-expansion.cpp test/CodeGenCXX/mangle-alias-template.cpp
Douglas Gregor
dgregor at apple.com
Fri Feb 3 09:16:23 PST 2012
Author: dgregor
Date: Fri Feb 3 11:16:23 2012
New Revision: 149697
URL: http://llvm.org/viewvc/llvm-project?rev=149697&view=rev
Log:
When a pack expansion occurs in the template argument list of an alias
template without a corresponding parameter pack, don't immediately
substitute the alias template. This is under discussion in the C++
committee, and may become ill-formed, but for now we match GCC.
Modified:
cfe/trunk/include/clang/AST/Type.h
cfe/trunk/include/clang/Sema/Sema.h
cfe/trunk/lib/AST/ASTContext.cpp
cfe/trunk/lib/AST/Type.cpp
cfe/trunk/lib/Sema/SemaTemplate.cpp
cfe/trunk/test/CXX/temp/temp.decls/temp.variadic/fixed-expansion.cpp
cfe/trunk/test/CodeGenCXX/mangle-alias-template.cpp
Modified: cfe/trunk/include/clang/AST/Type.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/AST/Type.h?rev=149697&r1=149696&r2=149697&view=diff
==============================================================================
--- cfe/trunk/include/clang/AST/Type.h (original)
+++ cfe/trunk/include/clang/AST/Type.h Fri Feb 3 11:16:23 2012
@@ -3484,8 +3484,12 @@
/// \brief - The number of template arguments named in this class
/// template specialization.
- unsigned NumArgs;
+ unsigned NumArgs : 31;
+ /// \brief Whether this template specialization type is a substituted
+ /// type alias.
+ bool TypeAlias : 1;
+
TemplateSpecializationType(TemplateName T,
const TemplateArgument *Args,
unsigned NumArgs, QualType Canon,
@@ -3527,9 +3531,23 @@
return isa<InjectedClassNameType>(getCanonicalTypeInternal());
}
- /// True if this template specialization type is for a type alias
- /// template.
- bool isTypeAlias() const;
+ /// \brief Determine if this template specialization type is for a type alias
+ /// template that has been substituted.
+ ///
+ /// Nearly every template specialization type whose template is an alias
+ /// template will be substituted. However, this is not the case when
+ /// the specialization contains a pack expansion but the template alias
+ /// does not have a corresponding parameter pack, e.g.,
+ ///
+ /// \code
+ /// template<typename T, typename U, typename V> struct S;
+ /// template<typename T, typename U> using A = S<T, int, U>;
+ /// template<typename... Ts> struct X {
+ /// typedef A<Ts...> type; // not a type alias
+ /// };
+ /// \endcode
+ bool isTypeAlias() const { return TypeAlias; }
+
/// Get the aliased type, if this is a specialization of a type alias
/// template.
QualType getAliasedType() const {
Modified: cfe/trunk/include/clang/Sema/Sema.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Sema/Sema.h?rev=149697&r1=149696&r2=149697&view=diff
==============================================================================
--- cfe/trunk/include/clang/Sema/Sema.h (original)
+++ cfe/trunk/include/clang/Sema/Sema.h Fri Feb 3 11:16:23 2012
@@ -4133,12 +4133,18 @@
/// \param Converted Will receive the converted, canonicalized template
/// arguments.
///
+ ///
+ /// \param ExpansionIntoFixedList If non-NULL, will be set true to indicate
+ /// when the template arguments contain a pack expansion that is being
+ /// expanded into a fixed parameter list.
+ ///
/// \returns True if an error occurred, false otherwise.
bool CheckTemplateArgumentList(TemplateDecl *Template,
SourceLocation TemplateLoc,
TemplateArgumentListInfo &TemplateArgs,
bool PartialTemplateArgs,
- SmallVectorImpl<TemplateArgument> &Converted);
+ SmallVectorImpl<TemplateArgument> &Converted,
+ bool *ExpansionIntoFixedList = 0);
bool CheckTemplateTypeArgument(TemplateTypeParmDecl *Param,
const TemplateArgumentLoc &Arg,
Modified: cfe/trunk/lib/AST/ASTContext.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ASTContext.cpp?rev=149697&r1=149696&r2=149697&view=diff
==============================================================================
--- cfe/trunk/lib/AST/ASTContext.cpp (original)
+++ cfe/trunk/lib/AST/ASTContext.cpp Fri Feb 3 11:16:23 2012
@@ -2450,6 +2450,17 @@
Underlying);
}
+#ifndef NDEBUG
+static bool hasAnyPackExpansions(const TemplateArgument *Args,
+ unsigned NumArgs) {
+ for (unsigned I = 0; I != NumArgs; ++I)
+ if (Args[I].isPackExpansion())
+ return true;
+
+ return true;
+}
+#endif
+
QualType
ASTContext::getTemplateSpecializationType(TemplateName Template,
const TemplateArgument *Args,
@@ -2461,16 +2472,18 @@
if (QualifiedTemplateName *QTN = Template.getAsQualifiedTemplateName())
Template = TemplateName(QTN->getTemplateDecl());
- bool isTypeAlias =
+ bool IsTypeAlias =
Template.getAsTemplateDecl() &&
isa<TypeAliasTemplateDecl>(Template.getAsTemplateDecl());
-
QualType CanonType;
if (!Underlying.isNull())
CanonType = getCanonicalType(Underlying);
else {
- assert(!isTypeAlias &&
- "Underlying type for template alias must be computed by caller");
+ // We can get here with an alias template when the specialization contains
+ // a pack expansion that does not match up with a parameter pack.
+ assert((!IsTypeAlias || hasAnyPackExpansions(Args, NumArgs)) &&
+ "Caller must compute aliased type");
+ IsTypeAlias = false;
CanonType = getCanonicalTemplateSpecializationType(Template, Args,
NumArgs);
}
@@ -2480,13 +2493,11 @@
// we don't unique and don't want to lose.
void *Mem = Allocate(sizeof(TemplateSpecializationType) +
sizeof(TemplateArgument) * NumArgs +
- (isTypeAlias ? sizeof(QualType) : 0),
+ (IsTypeAlias? sizeof(QualType) : 0),
TypeAlignment);
TemplateSpecializationType *Spec
- = new (Mem) TemplateSpecializationType(Template,
- Args, NumArgs,
- CanonType,
- isTypeAlias ? Underlying : QualType());
+ = new (Mem) TemplateSpecializationType(Template, Args, NumArgs, CanonType,
+ IsTypeAlias ? Underlying : QualType());
Types.push_back(Spec);
return QualType(Spec, 0);
@@ -2498,9 +2509,6 @@
unsigned NumArgs) const {
assert(!Template.getAsDependentTemplateName() &&
"No dependent template names here!");
- assert((!Template.getAsTemplateDecl() ||
- !isa<TypeAliasTemplateDecl>(Template.getAsTemplateDecl())) &&
- "Underlying type for template alias must be computed by caller");
// Look through qualified template names.
if (QualifiedTemplateName *QTN = Template.getAsQualifiedTemplateName())
Modified: cfe/trunk/lib/AST/Type.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/Type.cpp?rev=149697&r1=149696&r2=149697&view=diff
==============================================================================
--- cfe/trunk/lib/AST/Type.cpp (original)
+++ cfe/trunk/lib/AST/Type.cpp Fri Feb 3 11:16:23 2012
@@ -1884,7 +1884,7 @@
false,
Canon.isNull()? T.containsUnexpandedParameterPack()
: Canon->containsUnexpandedParameterPack()),
- Template(T), NumArgs(NumArgs) {
+ Template(T), NumArgs(NumArgs), TypeAlias(!AliasedType.isNull()) {
assert(!T.getAsDependentTemplateName() &&
"Use DependentTemplateSpecializationType for dependent template-name");
assert((T.getKind() == TemplateName::Template ||
@@ -1923,10 +1923,7 @@
}
// Store the aliased type if this is a type alias template specialization.
- bool IsTypeAlias = !AliasedType.isNull();
- assert(IsTypeAlias == isTypeAlias() &&
- "allocated wrong size for type alias");
- if (IsTypeAlias) {
+ if (TypeAlias) {
TemplateArgument *Begin = reinterpret_cast<TemplateArgument *>(this + 1);
*reinterpret_cast<QualType*>(Begin + getNumArgs()) = AliasedType;
}
@@ -1943,11 +1940,6 @@
Args[Idx].Profile(ID, Context);
}
-bool TemplateSpecializationType::isTypeAlias() const {
- TemplateDecl *D = Template.getAsTemplateDecl();
- return D && isa<TypeAliasTemplateDecl>(D);
-}
-
QualType
QualifierCollector::apply(const ASTContext &Context, QualType QT) const {
if (!hasNonFastQualifiers())
Modified: cfe/trunk/lib/Sema/SemaTemplate.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaTemplate.cpp?rev=149697&r1=149696&r2=149697&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaTemplate.cpp (original)
+++ cfe/trunk/lib/Sema/SemaTemplate.cpp Fri Feb 3 11:16:23 2012
@@ -1918,15 +1918,17 @@
// Check that the template argument list is well-formed for this
// template.
SmallVector<TemplateArgument, 4> Converted;
+ bool ExpansionIntoFixedList = false;
if (CheckTemplateArgumentList(Template, TemplateLoc, TemplateArgs,
- false, Converted))
+ false, Converted, &ExpansionIntoFixedList))
return QualType();
QualType CanonType;
bool InstantiationDependent = false;
- if (TypeAliasTemplateDecl *AliasTemplate
- = dyn_cast<TypeAliasTemplateDecl>(Template)) {
+ TypeAliasTemplateDecl *AliasTemplate = 0;
+ if (!ExpansionIntoFixedList &&
+ (AliasTemplate = dyn_cast<TypeAliasTemplateDecl>(Template))) {
// Find the canonical type for this type alias template specialization.
TypeAliasDecl *Pattern = AliasTemplate->getTemplatedDecl();
if (Pattern->isInvalidDecl())
@@ -2891,7 +2893,11 @@
SourceLocation TemplateLoc,
TemplateArgumentListInfo &TemplateArgs,
bool PartialTemplateArgs,
- SmallVectorImpl<TemplateArgument> &Converted) {
+ SmallVectorImpl<TemplateArgument> &Converted,
+ bool *ExpansionIntoFixedList) {
+ if (ExpansionIntoFixedList)
+ *ExpansionIntoFixedList = false;
+
TemplateParameterList *Params = Template->getTemplateParameters();
unsigned NumParams = Params->size();
unsigned NumArgs = TemplateArgs.size();
@@ -2901,7 +2907,7 @@
bool HasParameterPack =
NumParams > 0 && Params->getParam(NumParams - 1)->isTemplateParameterPack();
-
+
// C++ [temp.arg]p1:
// [...] The type and form of each template-argument specified in
// a template-id shall match the type and form specified for the
@@ -3088,6 +3094,9 @@
ArgumentPack.size()));
ArgumentPack.clear();
}
+ } else if (ExpansionIntoFixedList) {
+ // We have expanded a pack into a fixed list.
+ *ExpansionIntoFixedList = true;
}
return Invalid;
Modified: cfe/trunk/test/CXX/temp/temp.decls/temp.variadic/fixed-expansion.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/temp/temp.decls/temp.variadic/fixed-expansion.cpp?rev=149697&r1=149696&r2=149697&view=diff
==============================================================================
--- cfe/trunk/test/CXX/temp/temp.decls/temp.variadic/fixed-expansion.cpp (original)
+++ cfe/trunk/test/CXX/temp/temp.decls/temp.variadic/fixed-expansion.cpp Fri Feb 3 11:16:23 2012
@@ -118,3 +118,10 @@
X0<int, float> x0if;
X0<int, float, double> x0ifd;
}
+
+namespace FixedAliasTemplate {
+ template<typename,typename,typename> struct S {};
+ template<typename T, typename U> using U = S<T, int, U>;
+ template<typename...Ts> U<Ts...> &f(U<Ts...>, Ts...);
+ S<int, int, double> &s1 = f({}, 0, 0.0);
+}
Modified: cfe/trunk/test/CodeGenCXX/mangle-alias-template.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/mangle-alias-template.cpp?rev=149697&r1=149696&r2=149697&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/mangle-alias-template.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/mangle-alias-template.cpp Fri Feb 3 11:16:23 2012
@@ -11,6 +11,10 @@
template<template<typename> class F> void h(F<int>);
+template<typename,typename,typename> struct S {};
+template<typename T, typename U> using U = S<T, int, U>;
+template<typename...Ts> void h(U<Ts...>, Ts...);
+
// CHECK: define void @_Z1zv(
void z() {
vector<int> VI;
@@ -38,4 +42,7 @@
Vec<Vec<int>> VVI;
g(VVI);
// CHECK: call void @_Z1gI6vectorIS0_Ii5allocIiEES1_IS3_EEEvT_(
+
+ // CHECK: call void @_Z1hIJidEEv1UIDpT_ES2_
+ h({}, 0, 0.0);
}
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