//===------- SemaTemplateInstantiate.cpp - C++ Template Instantiation ------===/
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//===----------------------------------------------------------------------===/
//
// This file implements C++ template instantiation.
//
//===----------------------------------------------------------------------===/
#include "Sema.h"
#include "TreeTransform.h"
#include "clang/AST/ASTConsumer.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Expr.h"
#include "clang/AST/DeclTemplate.h"
#include "clang/Parse/DeclSpec.h"
#include "clang/Basic/LangOptions.h"
#include "llvm/Support/Compiler.h"
using namespace clang;
//===----------------------------------------------------------------------===/
// Template Instantiation Support
//===----------------------------------------------------------------------===/
/// \brief Retrieve the template argument list(s) that should be used to
/// instantiate the definition of the given declaration.
MultiLevelTemplateArgumentList
Sema::getTemplateInstantiationArgs(NamedDecl *D) {
// Accumulate the set of template argument lists in this structure.
MultiLevelTemplateArgumentList Result;
DeclContext *Ctx = dyn_cast<DeclContext>(D);
if (!Ctx)
Ctx = D->getDeclContext();
while (!Ctx->isFileContext()) {
// Add template arguments from a class template instantiation.
if (ClassTemplateSpecializationDecl *Spec
= dyn_cast<ClassTemplateSpecializationDecl>(Ctx)) {
// We're done when we hit an explicit specialization.
if (Spec->getSpecializationKind() == TSK_ExplicitSpecialization)
break;
Result.addOuterTemplateArguments(&Spec->getTemplateInstantiationArgs());
// If this class template specialization was instantiated from a
// specialized member that is a class template, we're done.
assert(Spec->getSpecializedTemplate() && "No class template?");
if (Spec->getSpecializedTemplate()->isMemberSpecialization())
break;
}
// Add template arguments from a function template specialization.
else if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Ctx)) {
if (Function->getTemplateSpecializationKind()
== TSK_ExplicitSpecialization)
break;
if (const TemplateArgumentList *TemplateArgs
= Function->getTemplateSpecializationArgs()) {
// Add the template arguments for this specialization.
Result.addOuterTemplateArguments(TemplateArgs);
// If this function was instantiated from a specialized member that is
// a function template, we're done.
assert(Function->getPrimaryTemplate() && "No function template?");
if (Function->getPrimaryTemplate()->isMemberSpecialization())
break;
}
// If this is a friend declaration and it declares an entity at
// namespace scope, take arguments from its lexical parent
// instead of its semantic parent.
if (Function->getFriendObjectKind() &&
Function->getDeclContext()->isFileContext()) {
Ctx = Function->getLexicalDeclContext();
continue;
}
}
Ctx = Ctx->getParent();
}
return Result;
}
Sema::InstantiatingTemplate::
InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
Decl *Entity,
SourceRange InstantiationRange)
: SemaRef(SemaRef) {
Invalid = CheckInstantiationDepth(PointOfInstantiation,
InstantiationRange);
if (!Invalid) {
ActiveTemplateInstantiation Inst;
Inst.Kind = ActiveTemplateInstantiation::TemplateInstantiation;
Inst.PointOfInstantiation = PointOfInstantiation;
Inst.Entity = reinterpret_cast<uintptr_t>(Entity);
Inst.TemplateArgs = 0;
Inst.NumTemplateArgs = 0;
Inst.InstantiationRange = InstantiationRange;
SemaRef.ActiveTemplateInstantiations.push_back(Inst);
Invalid = false;
}
}
Sema::InstantiatingTemplate::InstantiatingTemplate(Sema &SemaRef,
SourceLocation PointOfInstantiation,
TemplateDecl *Template,
const TemplateArgument *TemplateArgs,
unsigned NumTemplateArgs,
SourceRange InstantiationRange)
: SemaRef(SemaRef) {
Invalid = CheckInstantiationDepth(PointOfInstantiation,
InstantiationRange);
if (!Invalid) {
ActiveTemplateInstantiation Inst;
Inst.Kind
= ActiveTemplateInstantiation::DefaultTemplateArgumentInstantiation;
Inst.PointOfInstantiation = PointOfInstantiation;
Inst.Entity = reinterpret_cast<uintptr_t>(Template);
Inst.TemplateArgs = TemplateArgs;
Inst.NumTemplateArgs = NumTemplateArgs;
Inst.InstantiationRange = InstantiationRange;
SemaRef.ActiveTemplateInstantiations.push_back(Inst);
Invalid = false;
}
}
Sema::InstantiatingTemplate::InstantiatingTemplate(Sema &SemaRef,
SourceLocation PointOfInstantiation,
FunctionTemplateDecl *FunctionTemplate,
const TemplateArgument *TemplateArgs,
unsigned NumTemplateArgs,
ActiveTemplateInstantiation::InstantiationKind Kind,
SourceRange InstantiationRange)
: SemaRef(SemaRef) {
Invalid = CheckInstantiationDepth(PointOfInstantiation,
InstantiationRange);
if (!Invalid) {
ActiveTemplateInstantiation Inst;
Inst.Kind = Kind;
Inst.PointOfInstantiation = PointOfInstantiation;
Inst.Entity = reinterpret_cast<uintptr_t>(FunctionTemplate);
Inst.TemplateArgs = TemplateArgs;
Inst.NumTemplateArgs = NumTemplateArgs;
Inst.InstantiationRange = InstantiationRange;
SemaRef.ActiveTemplateInstantiations.push_back(Inst);
Invalid = false;
}
}
Sema::InstantiatingTemplate::InstantiatingTemplate(Sema &SemaRef,
SourceLocation PointOfInstantiation,
ClassTemplatePartialSpecializationDecl *PartialSpec,
const TemplateArgument *TemplateArgs,
unsigned NumTemplateArgs,
SourceRange InstantiationRange)
: SemaRef(SemaRef) {
Invalid = CheckInstantiationDepth(PointOfInstantiation,
InstantiationRange);
if (!Invalid) {
ActiveTemplateInstantiation Inst;
Inst.Kind
= ActiveTemplateInstantiation::DeducedTemplateArgumentSubstitution;
Inst.PointOfInstantiation = PointOfInstantiation;
Inst.Entity = reinterpret_cast<uintptr_t>(PartialSpec);
Inst.TemplateArgs = TemplateArgs;
Inst.NumTemplateArgs = NumTemplateArgs;
Inst.InstantiationRange = InstantiationRange;
SemaRef.ActiveTemplateInstantiations.push_back(Inst);
Invalid = false;
}
}
Sema::InstantiatingTemplate::InstantiatingTemplate(Sema &SemaRef,
SourceLocation PointOfInstantation,
ParmVarDecl *Param,
const TemplateArgument *TemplateArgs,
unsigned NumTemplateArgs,
SourceRange InstantiationRange)
: SemaRef(SemaRef) {
Invalid = CheckInstantiationDepth(PointOfInstantation, InstantiationRange);
if (!Invalid) {
ActiveTemplateInstantiation Inst;
Inst.Kind
= ActiveTemplateInstantiation::DefaultFunctionArgumentInstantiation;
Inst.PointOfInstantiation = PointOfInstantation;
Inst.Entity = reinterpret_cast<uintptr_t>(Param);
Inst.TemplateArgs = TemplateArgs;
Inst.NumTemplateArgs = NumTemplateArgs;
Inst.InstantiationRange = InstantiationRange;
SemaRef.ActiveTemplateInstantiations.push_back(Inst);
Invalid = false;
}
}
void Sema::InstantiatingTemplate::Clear() {
if (!Invalid) {
SemaRef.ActiveTemplateInstantiations.pop_back();
Invalid = true;
}
}
bool Sema::InstantiatingTemplate::CheckInstantiationDepth(
SourceLocation PointOfInstantiation,
SourceRange InstantiationRange) {
if (SemaRef.ActiveTemplateInstantiations.size()
<= SemaRef.getLangOptions().InstantiationDepth)
return false;
SemaRef.Diag(PointOfInstantiation,
diag::err_template_recursion_depth_exceeded)
<< SemaRef.getLangOptions().InstantiationDepth
<< InstantiationRange;
SemaRef.Diag(PointOfInstantiation, diag::note_template_recursion_depth)
<< SemaRef.getLangOptions().InstantiationDepth;
return true;
}
/// \brief Prints the current instantiation stack through a series of
/// notes.
void Sema::PrintInstantiationStack() {
// FIXME: In all of these cases, we need to show the template arguments
for (llvm::SmallVector<ActiveTemplateInstantiation, 16>::reverse_iterator
Active = ActiveTemplateInstantiations.rbegin(),
ActiveEnd = ActiveTemplateInstantiations.rend();
Active != ActiveEnd;
++Active) {
switch (Active->Kind) {
case ActiveTemplateInstantiation::TemplateInstantiation: {
Decl *D = reinterpret_cast<Decl *>(Active->Entity);
if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
unsigned DiagID = diag::note_template_member_class_here;
if (isa<ClassTemplateSpecializationDecl>(Record))
DiagID = diag::note_template_class_instantiation_here;
Diags.Report(FullSourceLoc(Active->PointOfInstantiation, SourceMgr),
DiagID)
<< Context.getTypeDeclType(Record)
<< Active->InstantiationRange;
} else if (FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) {
unsigned DiagID;
if (Function->getPrimaryTemplate())
DiagID = diag::note_function_template_spec_here;
else
DiagID = diag::note_template_member_function_here;
Diags.Report(FullSourceLoc(Active->PointOfInstantiation, SourceMgr),
DiagID)
<< Function
<< Active->InstantiationRange;
} else {
Diags.Report(FullSourceLoc(Active->PointOfInstantiation, SourceMgr),
diag::note_template_static_data_member_def_here)
<< cast<VarDecl>(D)
<< Active->InstantiationRange;
}
break;
}
case ActiveTemplateInstantiation::DefaultTemplateArgumentInstantiation: {
TemplateDecl *Template = cast<TemplateDecl>((Decl *)Active->Entity);
std::string TemplateArgsStr
= TemplateSpecializationType::PrintTemplateArgumentList(
Active->TemplateArgs,
Active->NumTemplateArgs,
Context.PrintingPolicy);
Diags.Report(FullSourceLoc(Active->PointOfInstantiation, SourceMgr),
diag::note_default_arg_instantiation_here)
<< (Template->getNameAsString() + TemplateArgsStr)
<< Active->InstantiationRange;
break;
}
case ActiveTemplateInstantiation::ExplicitTemplateArgumentSubstitution: {
FunctionTemplateDecl *FnTmpl
= cast<FunctionTemplateDecl>((Decl *)Active->Entity);
Diags.Report(FullSourceLoc(Active->PointOfInstantiation, SourceMgr),
diag::note_explicit_template_arg_substitution_here)
<< FnTmpl << Active->InstantiationRange;
break;
}
case ActiveTemplateInstantiation::DeducedTemplateArgumentSubstitution:
if (ClassTemplatePartialSpecializationDecl *PartialSpec
= dyn_cast<ClassTemplatePartialSpecializationDecl>(
(Decl *)Active->Entity)) {
Diags.Report(FullSourceLoc(Active->PointOfInstantiation, SourceMgr),
diag::note_partial_spec_deduct_instantiation_here)
<< Context.getTypeDeclType(PartialSpec)
<< Active->InstantiationRange;
} else {
FunctionTemplateDecl *FnTmpl
= cast<FunctionTemplateDecl>((Decl *)Active->Entity);
Diags.Report(FullSourceLoc(Active->PointOfInstantiation, SourceMgr),
diag::note_function_template_deduction_instantiation_here)
<< FnTmpl << Active->InstantiationRange;
}
break;
case ActiveTemplateInstantiation::DefaultFunctionArgumentInstantiation: {
ParmVarDecl *Param = cast<ParmVarDecl>((Decl *)Active->Entity);
FunctionDecl *FD = cast<FunctionDecl>(Param->getDeclContext());
std::string TemplateArgsStr
= TemplateSpecializationType::PrintTemplateArgumentList(
Active->TemplateArgs,
Active->NumTemplateArgs,
Context.PrintingPolicy);
Diags.Report(FullSourceLoc(Active->PointOfInstantiation, SourceMgr),
diag::note_default_function_arg_instantiation_here)
<< (FD->getNameAsString() + TemplateArgsStr)
<< Active->InstantiationRange;
break;
}
}
}
}
bool Sema::isSFINAEContext() const {
using llvm::SmallVector;
for (SmallVector<ActiveTemplateInstantiation, 16>::const_reverse_iterator
Active = ActiveTemplateInstantiations.rbegin(),
ActiveEnd = ActiveTemplateInstantiations.rend();
Active != ActiveEnd;
++Active) {
switch(Active->Kind) {
case ActiveTemplateInstantiation::TemplateInstantiation:
case ActiveTemplateInstantiation::DefaultFunctionArgumentInstantiation:
// This is a template instantiation, so there is no SFINAE.
return false;
case ActiveTemplateInstantiation::DefaultTemplateArgumentInstantiation:
// A default template argument instantiation may or may not be a
// SFINAE context; look further up the stack.
break;
case ActiveTemplateInstantiation::ExplicitTemplateArgumentSubstitution:
case ActiveTemplateInstantiation::DeducedTemplateArgumentSubstitution:
// We're either substitution explicitly-specified template arguments
// or deduced template arguments, so SFINAE applies.
return true;
}
}
return false;
}
//===----------------------------------------------------------------------===/
// Template Instantiation for Types
//===----------------------------------------------------------------------===/
namespace {
class VISIBILITY_HIDDEN TemplateInstantiator
: public TreeTransform<TemplateInstantiator> {
const MultiLevelTemplateArgumentList &TemplateArgs;
SourceLocation Loc;
DeclarationName Entity;
public:
typedef TreeTransform<TemplateInstantiator> inherited;
TemplateInstantiator(Sema &SemaRef,
const MultiLevelTemplateArgumentList &TemplateArgs,
SourceLocation Loc,
DeclarationName Entity)
: inherited(SemaRef), TemplateArgs(TemplateArgs), Loc(Loc),
Entity(Entity) { }
/// \brief Determine whether the given type \p T has already been
/// transformed.
///
/// For the purposes of template instantiation, a type has already been
/// transformed if it is NULL or if it is not dependent.
bool AlreadyTransformed(QualType T) {
return T.isNull() || !T->isDependentType();
}
/// \brief Returns the location of the entity being instantiated, if known.
SourceLocation getBaseLocation() { return Loc; }
/// \brief Returns the name of the entity being instantiated, if any.
DeclarationName getBaseEntity() { return Entity; }
/// \brief Transform the given declaration by instantiating a reference to
/// this declaration.
Decl *TransformDecl(Decl *D);
/// \brief Transform the definition of the given declaration by
/// instantiating it.
Decl *TransformDefinition(Decl *D);
/// \bried Transform the first qualifier within a scope by instantiating the
/// declaration.
NamedDecl *TransformFirstQualifierInScope(NamedDecl *D, SourceLocation Loc);
/// \brief Rebuild the exception declaration and register the declaration
/// as an instantiated local.
VarDecl *RebuildExceptionDecl(VarDecl *ExceptionDecl, QualType T,
DeclaratorInfo *Declarator,
IdentifierInfo *Name,
SourceLocation Loc, SourceRange TypeRange);
/// \brief Check for tag mismatches when instantiating an
/// elaborated type.
QualType RebuildElaboratedType(QualType T, ElaboratedType::TagKind Tag);
Sema::OwningExprResult TransformPredefinedExpr(PredefinedExpr *E);
Sema::OwningExprResult TransformDeclRefExpr(DeclRefExpr *E);
/// \brief Transforms a template type parameter type by performing
/// substitution of the corresponding template type argument.
QualType TransformTemplateTypeParmType(TypeLocBuilder &TLB,
TemplateTypeParmTypeLoc TL);
};
}
Decl *TemplateInstantiator::TransformDecl(Decl *D) {
if (!D)
return 0;
if (TemplateTemplateParmDecl *TTP = dyn_cast<TemplateTemplateParmDecl>(D)) {
if (TTP->getDepth() < TemplateArgs.getNumLevels()) {
assert(TemplateArgs(TTP->getDepth(), TTP->getPosition()).getAsDecl() &&
"Wrong kind of template template argument");
return cast<TemplateDecl>(TemplateArgs(TTP->getDepth(),
TTP->getPosition()).getAsDecl());
}
// If the corresponding template argument is NULL or non-existent, it's
// because we are performing instantiation from explicitly-specified
// template arguments in a function template, but there were some
// arguments left unspecified.
if (!TemplateArgs.hasTemplateArgument(TTP->getDepth(),
TTP->getPosition()))
return D;
// FIXME: Implement depth reduction of template template parameters
assert(false &&
"Reducing depth of template template parameters is not yet implemented");
}
return SemaRef.FindInstantiatedDecl(cast<NamedDecl>(D), TemplateArgs);
}
Decl *TemplateInstantiator::TransformDefinition(Decl *D) {
Decl *Inst = getSema().SubstDecl(D, getSema().CurContext, TemplateArgs);
if (!Inst)
return 0;
getSema().CurrentInstantiationScope->InstantiatedLocal(D, Inst);
return Inst;
}
NamedDecl *
TemplateInstantiator::TransformFirstQualifierInScope(NamedDecl *D,
SourceLocation Loc) {
// If the first part of the nested-name-specifier was a template type
// parameter, instantiate that type parameter down to a tag type.
if (TemplateTypeParmDecl *TTPD = dyn_cast_or_null<TemplateTypeParmDecl>(D)) {
const TemplateTypeParmType *TTP
= cast<TemplateTypeParmType>(getSema().Context.getTypeDeclType(TTPD));
if (TTP->getDepth() < TemplateArgs.getNumLevels()) {
QualType T = TemplateArgs(TTP->getDepth(), TTP->getIndex()).getAsType();
if (T.isNull())
return cast_or_null<NamedDecl>(TransformDecl(D));
if (const TagType *Tag = T->getAs<TagType>())
return Tag->getDecl();
// The resulting type is not a tag; complain.
getSema().Diag(Loc, diag::err_nested_name_spec_non_tag) << T;
return 0;
}
}
return cast_or_null<NamedDecl>(TransformDecl(D));
}
VarDecl *
TemplateInstantiator::RebuildExceptionDecl(VarDecl *ExceptionDecl,
QualType T,
DeclaratorInfo *Declarator,
IdentifierInfo *Name,
SourceLocation Loc,
SourceRange TypeRange) {
VarDecl *Var = inherited::RebuildExceptionDecl(ExceptionDecl, T, Declarator,
Name, Loc, TypeRange);
if (Var && !Var->isInvalidDecl())
getSema().CurrentInstantiationScope->InstantiatedLocal(ExceptionDecl, Var);
return Var;
}
QualType
TemplateInstantiator::RebuildElaboratedType(QualType T,
ElaboratedType::TagKind Tag) {
if (const TagType *TT = T->getAs<TagType>()) {
TagDecl* TD = TT->getDecl();
// FIXME: this location is very wrong; we really need typelocs.
SourceLocation TagLocation = TD->getTagKeywordLoc();
// FIXME: type might be anonymous.
IdentifierInfo *Id = TD->getIdentifier();
// TODO: should we even warn on struct/class mismatches for this? Seems
// like it's likely to produce a lot of spurious errors.
if (!SemaRef.isAcceptableTagRedeclaration(TD, Tag, TagLocation, *Id)) {
SemaRef.Diag(TagLocation, diag::err_use_with_wrong_tag)
<< Id
<< CodeModificationHint::CreateReplacement(SourceRange(TagLocation),
TD->getKindName());
SemaRef.Diag(TD->getLocation(), diag::note_previous_use);
}
}
return TreeTransform<TemplateInstantiator>::RebuildElaboratedType(T, Tag);
}
Sema::OwningExprResult
TemplateInstantiator::TransformPredefinedExpr(PredefinedExpr *E) {
if (!E->isTypeDependent())
return SemaRef.Owned(E->Retain());
FunctionDecl *currentDecl = getSema().getCurFunctionDecl();
assert(currentDecl && "Must have current function declaration when "
"instantiating.");
PredefinedExpr::IdentType IT = E->getIdentType();
unsigned Length =
PredefinedExpr::ComputeName(getSema().Context, IT, currentDecl).length();
llvm::APInt LengthI(32, Length + 1);
QualType ResTy = getSema().Context.CharTy.withConst();
ResTy = getSema().Context.getConstantArrayType(ResTy, LengthI,
ArrayType::Normal, 0);
PredefinedExpr *PE =
new (getSema().Context) PredefinedExpr(E->getLocation(), ResTy, IT);
return getSema().Owned(PE);
}
Sema::OwningExprResult
TemplateInstantiator::TransformDeclRefExpr(DeclRefExpr *E) {
// FIXME: Clean this up a bit
NamedDecl *D = E->getDecl();
if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(D)) {
if (NTTP->getDepth() >= TemplateArgs.getNumLevels()) {
assert(false && "Cannot reduce non-type template parameter depth yet");
return getSema().ExprError();
}
// If the corresponding template argument is NULL or non-existent, it's
// because we are performing instantiation from explicitly-specified
// template arguments in a function template, but there were some
// arguments left unspecified.
if (!TemplateArgs.hasTemplateArgument(NTTP->getDepth(),
NTTP->getPosition()))
return SemaRef.Owned(E->Retain());
const TemplateArgument &Arg = TemplateArgs(NTTP->getDepth(),
NTTP->getPosition());
// The template argument itself might be an expression, in which
// case we just return that expression.
if (Arg.getKind() == TemplateArgument::Expression)
return SemaRef.Owned(Arg.getAsExpr()->Retain());
if (Arg.getKind() == TemplateArgument::Declaration) {
ValueDecl *VD = cast<ValueDecl>(Arg.getAsDecl());
VD = cast_or_null<ValueDecl>(
getSema().FindInstantiatedDecl(VD, TemplateArgs));
if (!VD)
return SemaRef.ExprError();
return SemaRef.BuildDeclRefExpr(VD, VD->getType(), E->getLocation(),
/*FIXME:*/false, /*FIXME:*/false);
}
assert(Arg.getKind() == TemplateArgument::Integral);
QualType T = Arg.getIntegralType();
if (T->isCharType() || T->isWideCharType())
return SemaRef.Owned(new (SemaRef.Context) CharacterLiteral(
Arg.getAsIntegral()->getZExtValue(),
T->isWideCharType(),
T,
E->getSourceRange().getBegin()));
if (T->isBooleanType())
return SemaRef.Owned(new (SemaRef.Context) CXXBoolLiteralExpr(
Arg.getAsIntegral()->getBoolValue(),
T,
E->getSourceRange().getBegin()));
assert(Arg.getAsIntegral()->getBitWidth() == SemaRef.Context.getIntWidth(T));
return SemaRef.Owned(new (SemaRef.Context) IntegerLiteral(
*Arg.getAsIntegral(),
T,
E->getSourceRange().getBegin()));
}
NamedDecl *InstD = SemaRef.FindInstantiatedDecl(D, TemplateArgs);
if (!InstD)
return SemaRef.ExprError();
// If we instantiated an UnresolvedUsingDecl and got back an UsingDecl,
// we need to get the underlying decl.
// FIXME: Is this correct? Maybe FindInstantiatedDecl should do this?
InstD = InstD->getUnderlyingDecl();
// FIXME: nested-name-specifier for QualifiedDeclRefExpr
return SemaRef.BuildDeclarationNameExpr(E->getLocation(), InstD,
/*FIXME:*/false,
/*FIXME:*/0,
/*FIXME:*/false);
}
QualType
TemplateInstantiator::TransformTemplateTypeParmType(TypeLocBuilder &TLB,
TemplateTypeParmTypeLoc TL) {
TemplateTypeParmType *T = TL.getTypePtr();
if (T->getDepth() < TemplateArgs.getNumLevels()) {
// Replace the template type parameter with its corresponding
// template argument.
// If the corresponding template argument is NULL or doesn't exist, it's
// because we are performing instantiation from explicitly-specified
// template arguments in a function template class, but there were some
// arguments left unspecified.
if (!TemplateArgs.hasTemplateArgument(T->getDepth(), T->getIndex())) {
TemplateTypeParmTypeLoc NewTL
= TLB.push<TemplateTypeParmTypeLoc>(TL.getType());
NewTL.setNameLoc(TL.getNameLoc());
return TL.getType();
}
assert(TemplateArgs(T->getDepth(), T->getIndex()).getKind()
== TemplateArgument::Type &&
"Template argument kind mismatch");
QualType Replacement
= TemplateArgs(T->getDepth(), T->getIndex()).getAsType();
// TODO: only do this uniquing once, at the start of instantiation.
QualType Result
= getSema().Context.getSubstTemplateTypeParmType(T, Replacement);
SubstTemplateTypeParmTypeLoc NewTL
= TLB.push<SubstTemplateTypeParmTypeLoc>(Result);
NewTL.setNameLoc(TL.getNameLoc());
return Result;
}
// The template type parameter comes from an inner template (e.g.,
// the template parameter list of a member template inside the
// template we are instantiating). Create a new template type
// parameter with the template "level" reduced by one.
QualType Result
= getSema().Context.getTemplateTypeParmType(T->getDepth()
- TemplateArgs.getNumLevels(),
T->getIndex(),
T->isParameterPack(),
T->getName());
TemplateTypeParmTypeLoc NewTL = TLB.push<TemplateTypeParmTypeLoc>(Result);
NewTL.setNameLoc(TL.getNameLoc());
return Result;
}
/// \brief Perform substitution on the type T with a given set of template
/// arguments.
///
/// This routine substitutes the given template arguments into the
/// type T and produces the instantiated type.
///
/// \param T the type into which the template arguments will be
/// substituted. If this type is not dependent, it will be returned
/// immediately.
///
/// \param TemplateArgs the template arguments that will be
/// substituted for the top-level template parameters within T.
///
/// \param Loc the location in the source code where this substitution
/// is being performed. It will typically be the location of the
/// declarator (if we're instantiating the type of some declaration)
/// or the location of the type in the source code (if, e.g., we're
/// instantiating the type of a cast expression).
///
/// \param Entity the name of the entity associated with a declaration
/// being instantiated (if any). May be empty to indicate that there
/// is no such entity (if, e.g., this is a type that occurs as part of
/// a cast expression) or that the entity has no name (e.g., an
/// unnamed function parameter).
///
/// \returns If the instantiation succeeds, the instantiated
/// type. Otherwise, produces diagnostics and returns a NULL type.
DeclaratorInfo *Sema::SubstType(DeclaratorInfo *T,
const MultiLevelTemplateArgumentList &Args,
SourceLocation Loc,
DeclarationName Entity) {
assert(!ActiveTemplateInstantiations.empty() &&
"Cannot perform an instantiation without some context on the "
"instantiation stack");
if (!T->getType()->isDependentType())
return T;
TemplateInstantiator Instantiator(*this, Args, Loc, Entity);
return Instantiator.TransformType(T);
}
/// Deprecated form of the above.
QualType Sema::SubstType(QualType T,
const MultiLevelTemplateArgumentList &TemplateArgs,
SourceLocation Loc, DeclarationName Entity) {
assert(!ActiveTemplateInstantiations.empty() &&
"Cannot perform an instantiation without some context on the "
"instantiation stack");
// If T is not a dependent type, there is nothing to do.
if (!T->isDependentType())
return T;
TemplateInstantiator Instantiator(*this, TemplateArgs, Loc, Entity);
return Instantiator.TransformType(T);
}
/// \brief Perform substitution on the base class specifiers of the
/// given class template specialization.
///
/// Produces a diagnostic and returns true on error, returns false and
/// attaches the instantiated base classes to the class template
/// specialization if successful.
bool
Sema::SubstBaseSpecifiers(CXXRecordDecl *Instantiation,
CXXRecordDecl *Pattern,
const MultiLevelTemplateArgumentList &TemplateArgs) {
bool Invalid = false;
llvm::SmallVector<CXXBaseSpecifier*, 4> InstantiatedBases;
for (ClassTemplateSpecializationDecl::base_class_iterator
Base = Pattern->bases_begin(), BaseEnd = Pattern->bases_end();
Base != BaseEnd; ++Base) {
if (!Base->getType()->isDependentType()) {
InstantiatedBases.push_back(new (Context) CXXBaseSpecifier(*Base));
continue;
}
QualType BaseType = SubstType(Base->getType(),
TemplateArgs,
Base->getSourceRange().getBegin(),
DeclarationName());
if (BaseType.isNull()) {
Invalid = true;
continue;
}
if (CXXBaseSpecifier *InstantiatedBase
= CheckBaseSpecifier(Instantiation,
Base->getSourceRange(),
Base->isVirtual(),
Base->getAccessSpecifierAsWritten(),
BaseType,
/*FIXME: Not totally accurate */
Base->getSourceRange().getBegin()))
InstantiatedBases.push_back(InstantiatedBase);
else
Invalid = true;
}
if (!Invalid &&
AttachBaseSpecifiers(Instantiation, InstantiatedBases.data(),
InstantiatedBases.size()))
Invalid = true;
return Invalid;
}
/// \brief Instantiate the definition of a class from a given pattern.
///
/// \param PointOfInstantiation The point of instantiation within the
/// source code.
///
/// \param Instantiation is the declaration whose definition is being
/// instantiated. This will be either a class template specialization
/// or a member class of a class template specialization.
///
/// \param Pattern is the pattern from which the instantiation
/// occurs. This will be either the declaration of a class template or
/// the declaration of a member class of a class template.
///
/// \param TemplateArgs The template arguments to be substituted into
/// the pattern.
///
/// \param TSK the kind of implicit or explicit instantiation to perform.
///
/// \param Complain whether to complain if the class cannot be instantiated due
/// to the lack of a definition.
///
/// \returns true if an error occurred, false otherwise.
bool
Sema::InstantiateClass(SourceLocation PointOfInstantiation,
CXXRecordDecl *Instantiation, CXXRecordDecl *Pattern,
const MultiLevelTemplateArgumentList &TemplateArgs,
TemplateSpecializationKind TSK,
bool Complain) {
bool Invalid = false;
CXXRecordDecl *PatternDef
= cast_or_null<CXXRecordDecl>(Pattern->getDefinition(Context));
if (!PatternDef) {
if (!Complain) {
// Say nothing
} else if (Pattern == Instantiation->getInstantiatedFromMemberClass()) {
Diag(PointOfInstantiation,
diag::err_implicit_instantiate_member_undefined)
<< Context.getTypeDeclType(Instantiation);
Diag(Pattern->getLocation(), diag::note_member_of_template_here);
} else {
Diag(PointOfInstantiation, diag::err_template_instantiate_undefined)
<< (TSK != TSK_ImplicitInstantiation)
<< Context.getTypeDeclType(Instantiation);
Diag(Pattern->getLocation(), diag::note_template_decl_here);
}
return true;
}
Pattern = PatternDef;
// \brief Record the point of instantiation.
if (MemberSpecializationInfo *MSInfo
= Instantiation->getMemberSpecializationInfo()) {
MSInfo->setTemplateSpecializationKind(TSK);
MSInfo->setPointOfInstantiation(PointOfInstantiation);
}
InstantiatingTemplate Inst(*this, PointOfInstantiation, Instantiation);
if (Inst)
return true;
// Enter the scope of this instantiation. We don't use
// PushDeclContext because we don't have a scope.
DeclContext *PreviousContext = CurContext;
CurContext = Instantiation;
// Start the definition of this instantiation.
Instantiation->startDefinition();
// Do substitution on the base class specifiers.
if (SubstBaseSpecifiers(Instantiation, Pattern, TemplateArgs))
Invalid = true;
llvm::SmallVector<DeclPtrTy, 4> Fields;
for (RecordDecl::decl_iterator Member = Pattern->decls_begin(),
MemberEnd = Pattern->decls_end();
Member != MemberEnd; ++Member) {
Decl *NewMember = SubstDecl(*Member, Instantiation, TemplateArgs);
if (NewMember) {
if (NewMember->isInvalidDecl())
Invalid = true;
else if (FieldDecl *Field = dyn_cast<FieldDecl>(NewMember))
Fields.push_back(DeclPtrTy::make(Field));
else if (UsingDecl *UD = dyn_cast<UsingDecl>(NewMember))
Instantiation->addDecl(UD);
} else {
// FIXME: Eventually, a NULL return will mean that one of the
// instantiations was a semantic disaster, and we'll want to set Invalid =
// true. For now, we expect to skip some members that we can't yet handle.
}
}
// Finish checking fields.
ActOnFields(0, Instantiation->getLocation(), DeclPtrTy::make(Instantiation),
Fields.data(), Fields.size(), SourceLocation(), SourceLocation(),
0);
if (Instantiation->isInvalidDecl())
Invalid = true;
// Add any implicitly-declared members that we might need.
if (!Invalid)
AddImplicitlyDeclaredMembersToClass(Instantiation);
// Exit the scope of this instantiation.
CurContext = PreviousContext;
if (!Invalid)
Consumer.HandleTagDeclDefinition(Instantiation);
// If this is an explicit instantiation, instantiate our members, too.
if (!Invalid && TSK != TSK_ImplicitInstantiation) {
Inst.Clear();
InstantiateClassMembers(PointOfInstantiation, Instantiation, TemplateArgs,
TSK);
}
return Invalid;
}
bool
Sema::InstantiateClassTemplateSpecialization(
ClassTemplateSpecializationDecl *ClassTemplateSpec,
TemplateSpecializationKind TSK,
bool Complain) {
// Perform the actual instantiation on the canonical declaration.
ClassTemplateSpec = cast<ClassTemplateSpecializationDecl>(
ClassTemplateSpec->getCanonicalDecl());
// Check whether we have already instantiated or specialized this class
// template specialization.
if (ClassTemplateSpec->getSpecializationKind() != TSK_Undeclared) {
if (ClassTemplateSpec->getSpecializationKind() ==
TSK_ExplicitInstantiationDeclaration &&
TSK == TSK_ExplicitInstantiationDefinition) {
// An explicit instantiation definition follows an explicit instantiation
// declaration (C++0x [temp.explicit]p10); go ahead and perform the
// explicit instantiation.
ClassTemplateSpec->setSpecializationKind(TSK);
InstantiateClassTemplateSpecializationMembers(
/*FIXME?*/ClassTemplateSpec->getPointOfInstantiation(),
ClassTemplateSpec,
TSK);
return false;
}
// We can only instantiate something that hasn't already been
// instantiated or specialized. Fail without any diagnostics: our
// caller will provide an error message.
return true;
}
if (ClassTemplateSpec->isInvalidDecl())
return true;
ClassTemplateDecl *Template = ClassTemplateSpec->getSpecializedTemplate();
CXXRecordDecl *Pattern = 0;
// C++ [temp.class.spec.match]p1:
// When a class template is used in a context that requires an
// instantiation of the class, it is necessary to determine
// whether the instantiation is to be generated using the primary
// template or one of the partial specializations. This is done by
// matching the template arguments of the class template
// specialization with the template argument lists of the partial
// specializations.
typedef std::pair<ClassTemplatePartialSpecializationDecl *,
TemplateArgumentList *> MatchResult;
llvm::SmallVector<MatchResult, 4> Matched;
for (llvm::FoldingSet<ClassTemplatePartialSpecializationDecl>::iterator
Partial = Template->getPartialSpecializations().begin(),
PartialEnd = Template->getPartialSpecializations().end();
Partial != PartialEnd;
++Partial) {
TemplateDeductionInfo Info(Context);
if (TemplateDeductionResult Result
= DeduceTemplateArguments(&*Partial,
ClassTemplateSpec->getTemplateArgs(),
Info)) {
// FIXME: Store the failed-deduction information for use in
// diagnostics, later.
(void)Result;
} else {
Matched.push_back(std::make_pair(&*Partial, Info.take()));
}
}
if (Matched.size() == 1) {
// -- If exactly one matching specialization is found, the
// instantiation is generated from that specialization.
Pattern = Matched[0].first;
ClassTemplateSpec->setInstantiationOf(Matched[0].first, Matched[0].second);
} else if (Matched.size() > 1) {
// -- If more than one matching specialization is found, the
// partial order rules (14.5.4.2) are used to determine
// whether one of the specializations is more specialized
// than the others. If none of the specializations is more
// specialized than all of the other matching
// specializations, then the use of the class template is
// ambiguous and the program is ill-formed.
llvm::SmallVector<MatchResult, 4>::iterator Best = Matched.begin();
for (llvm::SmallVector<MatchResult, 4>::iterator P = Best + 1,
PEnd = Matched.end();
P != PEnd; ++P) {
if (getMoreSpecializedPartialSpecialization(P->first, Best->first)
== P->first)
Best = P;
}
// Determine if the best partial specialization is more specialized than
// the others.
bool Ambiguous = false;
for (llvm::SmallVector<MatchResult, 4>::iterator P = Matched.begin(),
PEnd = Matched.end();
P != PEnd; ++P) {
if (P != Best &&
getMoreSpecializedPartialSpecialization(P->first, Best->first)
!= Best->first) {
Ambiguous = true;
break;
}
}
if (Ambiguous) {
// Partial ordering did not produce a clear winner. Complain.
ClassTemplateSpec->setInvalidDecl();
Diag(ClassTemplateSpec->getPointOfInstantiation(),
diag::err_partial_spec_ordering_ambiguous)
<< ClassTemplateSpec;
// Print the matching partial specializations.
for (llvm::SmallVector<MatchResult, 4>::iterator P = Matched.begin(),
PEnd = Matched.end();
P != PEnd; ++P)
Diag(P->first->getLocation(), diag::note_partial_spec_match)
<< getTemplateArgumentBindingsText(P->first->getTemplateParameters(),
*P->second);
return true;
}
// Instantiate using the best class template partial specialization.
Pattern = Best->first;
ClassTemplateSpec->setInstantiationOf(Best->first, Best->second);
} else {
// -- If no matches are found, the instantiation is generated
// from the primary template.
ClassTemplateDecl *OrigTemplate = Template;
while (OrigTemplate->getInstantiatedFromMemberTemplate()) {
// If we've found an explicit specialization of this class template,
// stop here and use that as the pattern.
if (OrigTemplate->isMemberSpecialization())
break;
OrigTemplate = OrigTemplate->getInstantiatedFromMemberTemplate();
}
Pattern = OrigTemplate->getTemplatedDecl();
}
// Note that this is an instantiation.
ClassTemplateSpec->setSpecializationKind(TSK);
bool Result = InstantiateClass(ClassTemplateSpec->getPointOfInstantiation(),
ClassTemplateSpec, Pattern,
getTemplateInstantiationArgs(ClassTemplateSpec),
TSK,
Complain);
for (unsigned I = 0, N = Matched.size(); I != N; ++I) {
// FIXME: Implement TemplateArgumentList::Destroy!
// if (Matched[I].first != Pattern)
// Matched[I].second->Destroy(Context);
}
return Result;
}
/// \brief Instantiates the definitions of all of the member
/// of the given class, which is an instantiation of a class template
/// or a member class of a template.
void
Sema::InstantiateClassMembers(SourceLocation PointOfInstantiation,
CXXRecordDecl *Instantiation,
const MultiLevelTemplateArgumentList &TemplateArgs,
TemplateSpecializationKind TSK) {
for (DeclContext::decl_iterator D = Instantiation->decls_begin(),
DEnd = Instantiation->decls_end();
D != DEnd; ++D) {
if (FunctionDecl *Function = dyn_cast<FunctionDecl>(*D)) {
if (Function->getInstantiatedFromMemberFunction()) {
// If this member was explicitly specialized, do nothing.
if (Function->getTemplateSpecializationKind() ==
TSK_ExplicitSpecialization)
continue;
Function->setTemplateSpecializationKind(TSK, PointOfInstantiation);
}
if (!Function->getBody() && TSK == TSK_ExplicitInstantiationDefinition)
InstantiateFunctionDefinition(PointOfInstantiation, Function);
} else if (VarDecl *Var = dyn_cast<VarDecl>(*D)) {
if (Var->isStaticDataMember()) {
// If this member was explicitly specialized, do nothing.
if (Var->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
continue;
Var->setTemplateSpecializationKind(TSK, PointOfInstantiation);
if (TSK == TSK_ExplicitInstantiationDefinition)
InstantiateStaticDataMemberDefinition(PointOfInstantiation, Var);
}
} else if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(*D)) {
if (Record->isInjectedClassName())
continue;
assert(Record->getInstantiatedFromMemberClass() &&
"Missing instantiated-from-template information");
// If this member was explicitly specialized, do nothing.
if (Record->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
continue;
if (!Record->getDefinition(Context))
InstantiateClass(PointOfInstantiation, Record,
Record->getInstantiatedFromMemberClass(),
TemplateArgs,
TSK);
InstantiateClassMembers(PointOfInstantiation, Record, TemplateArgs,
TSK);
}
}
}
/// \brief Instantiate the definitions of all of the members of the
/// given class template specialization, which was named as part of an
/// explicit instantiation.
void
Sema::InstantiateClassTemplateSpecializationMembers(
SourceLocation PointOfInstantiation,
ClassTemplateSpecializationDecl *ClassTemplateSpec,
TemplateSpecializationKind TSK) {
// C++0x [temp.explicit]p7:
// An explicit instantiation that names a class template
// specialization is an explicit instantion of the same kind
// (declaration or definition) of each of its members (not
// including members inherited from base classes) that has not
// been previously explicitly specialized in the translation unit
// containing the explicit instantiation, except as described
// below.
InstantiateClassMembers(PointOfInstantiation, ClassTemplateSpec,
getTemplateInstantiationArgs(ClassTemplateSpec),
TSK);
}
Sema::OwningStmtResult
Sema::SubstStmt(Stmt *S, const MultiLevelTemplateArgumentList &TemplateArgs) {
if (!S)
return Owned(S);
TemplateInstantiator Instantiator(*this, TemplateArgs,
SourceLocation(),
DeclarationName());
return Instantiator.TransformStmt(S);
}
Sema::OwningExprResult
Sema::SubstExpr(Expr *E, const MultiLevelTemplateArgumentList &TemplateArgs) {
if (!E)
return Owned(E);
TemplateInstantiator Instantiator(*this, TemplateArgs,
SourceLocation(),
DeclarationName());
return Instantiator.TransformExpr(E);
}
/// \brief Do template substitution on a nested-name-specifier.
NestedNameSpecifier *
Sema::SubstNestedNameSpecifier(NestedNameSpecifier *NNS,
SourceRange Range,
const MultiLevelTemplateArgumentList &TemplateArgs) {
TemplateInstantiator Instantiator(*this, TemplateArgs, Range.getBegin(),
DeclarationName());
return Instantiator.TransformNestedNameSpecifier(NNS, Range);
}
TemplateName
Sema::SubstTemplateName(TemplateName Name, SourceLocation Loc,
const MultiLevelTemplateArgumentList &TemplateArgs) {
TemplateInstantiator Instantiator(*this, TemplateArgs, Loc,
DeclarationName());
return Instantiator.TransformTemplateName(Name);
}
TemplateArgument Sema::Subst(TemplateArgument Arg,
const MultiLevelTemplateArgumentList &TemplateArgs) {
TemplateInstantiator Instantiator(*this, TemplateArgs, SourceLocation(),
DeclarationName());
return Instantiator.TransformTemplateArgument(Arg);
}