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//===------- SemaTemplateInstantiate.cpp - C++ Template Instantiation ------===/
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//===----------------------------------------------------------------------===/
//
// This file implements C++ template instantiation.
//
//===----------------------------------------------------------------------===/
#include "clang/Sema/SemaInternal.h"
#include "TreeTransform.h"
#include "clang/AST/ASTConsumer.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/ASTLambda.h"
#include "clang/AST/ASTMutationListener.h"
#include "clang/AST/DeclTemplate.h"
#include "clang/AST/Expr.h"
#include "clang/AST/PrettyDeclStackTrace.h"
#include "clang/Basic/LangOptions.h"
#include "clang/Sema/DeclSpec.h"
#include "clang/Sema/Initialization.h"
#include "clang/Sema/Lookup.h"
#include "clang/Sema/Template.h"
#include "clang/Sema/TemplateDeduction.h"
#include "clang/Sema/TemplateInstCallback.h"
#include "llvm/Support/TimeProfiler.h"
using namespace clang;
using namespace sema;
//===----------------------------------------------------------------------===/
// Template Instantiation Support
//===----------------------------------------------------------------------===/
/// Retrieve the template argument list(s) that should be used to
/// instantiate the definition of the given declaration.
///
/// \param D the declaration for which we are computing template instantiation
/// arguments.
///
/// \param Innermost if non-NULL, the innermost template argument list.
///
/// \param RelativeToPrimary true if we should get the template
/// arguments relative to the primary template, even when we're
/// dealing with a specialization. This is only relevant for function
/// template specializations.
///
/// \param Pattern If non-NULL, indicates the pattern from which we will be
/// instantiating the definition of the given declaration, \p D. This is
/// used to determine the proper set of template instantiation arguments for
/// friend function template specializations.
MultiLevelTemplateArgumentList
Sema::getTemplateInstantiationArgs(NamedDecl *D,
const TemplateArgumentList *Innermost,
bool RelativeToPrimary,
const FunctionDecl *Pattern) {
// Accumulate the set of template argument lists in this structure.
MultiLevelTemplateArgumentList Result;
if (Innermost)
Result.addOuterTemplateArguments(Innermost);
DeclContext *Ctx = dyn_cast<DeclContext>(D);
if (!Ctx) {
Ctx = D->getDeclContext();
// Add template arguments from a variable template instantiation. For a
// class-scope explicit specialization, there are no template arguments
// at this level, but there may be enclosing template arguments.
VarTemplateSpecializationDecl *Spec =
dyn_cast<VarTemplateSpecializationDecl>(D);
if (Spec && !Spec->isClassScopeExplicitSpecialization()) {
// We're done when we hit an explicit specialization.
if (Spec->getSpecializationKind() == TSK_ExplicitSpecialization &&
!isa<VarTemplatePartialSpecializationDecl>(Spec))
return Result;
Result.addOuterTemplateArguments(&Spec->getTemplateInstantiationArgs());
// If this variable template specialization was instantiated from a
// specialized member that is a variable template, we're done.
assert(Spec->getSpecializedTemplate() && "No variable template?");
llvm::PointerUnion<VarTemplateDecl*,
VarTemplatePartialSpecializationDecl*> Specialized
= Spec->getSpecializedTemplateOrPartial();
if (VarTemplatePartialSpecializationDecl *Partial =
Specialized.dyn_cast<VarTemplatePartialSpecializationDecl *>()) {
if (Partial->isMemberSpecialization())
return Result;
} else {
VarTemplateDecl *Tmpl = Specialized.get<VarTemplateDecl *>();
if (Tmpl->isMemberSpecialization())
return Result;
}
}
// If we have a template template parameter with translation unit context,
// then we're performing substitution into a default template argument of
// this template template parameter before we've constructed the template
// that will own this template template parameter. In this case, we
// use empty template parameter lists for all of the outer templates
// to avoid performing any substitutions.
if (Ctx->isTranslationUnit()) {
if (TemplateTemplateParmDecl *TTP
= dyn_cast<TemplateTemplateParmDecl>(D)) {
for (unsigned I = 0, N = TTP->getDepth() + 1; I != N; ++I)
Result.addOuterTemplateArguments(None);
return Result;
}
}
}
while (!Ctx->isFileContext()) {
// Add template arguments from a class template instantiation.
ClassTemplateSpecializationDecl *Spec
= dyn_cast<ClassTemplateSpecializationDecl>(Ctx);
if (Spec && !Spec->isClassScopeExplicitSpecialization()) {
// We're done when we hit an explicit specialization.
if (Spec->getSpecializationKind() == TSK_ExplicitSpecialization &&
!isa<ClassTemplatePartialSpecializationDecl>(Spec))
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 (!RelativeToPrimary &&
Function->getTemplateSpecializationKindForInstantiation() ==
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 function is a generic lambda specialization, we are done.
if (isGenericLambdaCallOperatorSpecialization(Function))
break;
} else if (FunctionTemplateDecl *FunTmpl
= Function->getDescribedFunctionTemplate()) {
// Add the "injected" template arguments.
Result.addOuterTemplateArguments(FunTmpl->getInjectedTemplateArgs());
}
// 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, unless of course the pattern we're
// instantiating actually comes from the file's context!
if (Function->getFriendObjectKind() &&
Function->getDeclContext()->isFileContext() &&
(!Pattern || !Pattern->getLexicalDeclContext()->isFileContext())) {
Ctx = Function->getLexicalDeclContext();
RelativeToPrimary = false;
continue;
}
} else if (CXXRecordDecl *Rec = dyn_cast<CXXRecordDecl>(Ctx)) {
if (ClassTemplateDecl *ClassTemplate = Rec->getDescribedClassTemplate()) {
QualType T = ClassTemplate->getInjectedClassNameSpecialization();
const TemplateSpecializationType *TST =
cast<TemplateSpecializationType>(Context.getCanonicalType(T));
Result.addOuterTemplateArguments(
llvm::makeArrayRef(TST->getArgs(), TST->getNumArgs()));
if (ClassTemplate->isMemberSpecialization())
break;
}
}
Ctx = Ctx->getParent();
RelativeToPrimary = false;
}
return Result;
}
bool Sema::CodeSynthesisContext::isInstantiationRecord() const {
switch (Kind) {
case TemplateInstantiation:
case ExceptionSpecInstantiation:
case DefaultTemplateArgumentInstantiation:
case DefaultFunctionArgumentInstantiation:
case ExplicitTemplateArgumentSubstitution:
case DeducedTemplateArgumentSubstitution:
case PriorTemplateArgumentSubstitution:
return true;
case DefaultTemplateArgumentChecking:
case DeclaringSpecialMember:
case DefiningSynthesizedFunction:
case ExceptionSpecEvaluation:
return false;
// This function should never be called when Kind's value is Memoization.
case Memoization:
break;
}
llvm_unreachable("Invalid SynthesisKind!");
}
Sema::InstantiatingTemplate::InstantiatingTemplate(
Sema &SemaRef, CodeSynthesisContext::SynthesisKind Kind,
SourceLocation PointOfInstantiation, SourceRange InstantiationRange,
Decl *Entity, NamedDecl *Template, ArrayRef<TemplateArgument> TemplateArgs,
sema::TemplateDeductionInfo *DeductionInfo)
: SemaRef(SemaRef) {
// Don't allow further instantiation if a fatal error and an uncompilable
// error have occurred. Any diagnostics we might have raised will not be
// visible, and we do not need to construct a correct AST.
if (SemaRef.Diags.hasFatalErrorOccurred() &&
SemaRef.Diags.hasUncompilableErrorOccurred()) {
Invalid = true;
return;
}
Invalid = CheckInstantiationDepth(PointOfInstantiation, InstantiationRange);
if (!Invalid) {
CodeSynthesisContext Inst;
Inst.Kind = Kind;
Inst.PointOfInstantiation = PointOfInstantiation;
Inst.Entity = Entity;
Inst.Template = Template;
Inst.TemplateArgs = TemplateArgs.data();
Inst.NumTemplateArgs = TemplateArgs.size();
Inst.DeductionInfo = DeductionInfo;
Inst.InstantiationRange = InstantiationRange;
SemaRef.pushCodeSynthesisContext(Inst);
AlreadyInstantiating =
!SemaRef.InstantiatingSpecializations
.insert(std::make_pair(Inst.Entity->getCanonicalDecl(), Inst.Kind))
.second;
atTemplateBegin(SemaRef.TemplateInstCallbacks, SemaRef, Inst);
}
}
Sema::InstantiatingTemplate::InstantiatingTemplate(
Sema &SemaRef, SourceLocation PointOfInstantiation, Decl *Entity,
SourceRange InstantiationRange)
: InstantiatingTemplate(SemaRef,
CodeSynthesisContext::TemplateInstantiation,
PointOfInstantiation, InstantiationRange, Entity) {}
Sema::InstantiatingTemplate::InstantiatingTemplate(
Sema &SemaRef, SourceLocation PointOfInstantiation, FunctionDecl *Entity,
ExceptionSpecification, SourceRange InstantiationRange)
: InstantiatingTemplate(
SemaRef, CodeSynthesisContext::ExceptionSpecInstantiation,
PointOfInstantiation, InstantiationRange, Entity) {}
Sema::InstantiatingTemplate::InstantiatingTemplate(
Sema &SemaRef, SourceLocation PointOfInstantiation, TemplateParameter Param,
TemplateDecl *Template, ArrayRef<TemplateArgument> TemplateArgs,
SourceRange InstantiationRange)
: InstantiatingTemplate(
SemaRef,
CodeSynthesisContext::DefaultTemplateArgumentInstantiation,
PointOfInstantiation, InstantiationRange, getAsNamedDecl(Param),
Template, TemplateArgs) {}
Sema::InstantiatingTemplate::InstantiatingTemplate(
Sema &SemaRef, SourceLocation PointOfInstantiation,
FunctionTemplateDecl *FunctionTemplate,
ArrayRef<TemplateArgument> TemplateArgs,
CodeSynthesisContext::SynthesisKind Kind,
sema::TemplateDeductionInfo &DeductionInfo, SourceRange InstantiationRange)
: InstantiatingTemplate(SemaRef, Kind, PointOfInstantiation,
InstantiationRange, FunctionTemplate, nullptr,
TemplateArgs, &DeductionInfo) {
assert(
Kind == CodeSynthesisContext::ExplicitTemplateArgumentSubstitution ||
Kind == CodeSynthesisContext::DeducedTemplateArgumentSubstitution);
}
Sema::InstantiatingTemplate::InstantiatingTemplate(
Sema &SemaRef, SourceLocation PointOfInstantiation,
TemplateDecl *Template,
ArrayRef<TemplateArgument> TemplateArgs,
sema::TemplateDeductionInfo &DeductionInfo, SourceRange InstantiationRange)
: InstantiatingTemplate(
SemaRef,
CodeSynthesisContext::DeducedTemplateArgumentSubstitution,
PointOfInstantiation, InstantiationRange, Template, nullptr,
TemplateArgs, &DeductionInfo) {}
Sema::InstantiatingTemplate::InstantiatingTemplate(
Sema &SemaRef, SourceLocation PointOfInstantiation,
ClassTemplatePartialSpecializationDecl *PartialSpec,
ArrayRef<TemplateArgument> TemplateArgs,
sema::TemplateDeductionInfo &DeductionInfo, SourceRange InstantiationRange)
: InstantiatingTemplate(
SemaRef,
CodeSynthesisContext::DeducedTemplateArgumentSubstitution,
PointOfInstantiation, InstantiationRange, PartialSpec, nullptr,
TemplateArgs, &DeductionInfo) {}
Sema::InstantiatingTemplate::InstantiatingTemplate(
Sema &SemaRef, SourceLocation PointOfInstantiation,
VarTemplatePartialSpecializationDecl *PartialSpec,
ArrayRef<TemplateArgument> TemplateArgs,
sema::TemplateDeductionInfo &DeductionInfo, SourceRange InstantiationRange)
: InstantiatingTemplate(
SemaRef,
CodeSynthesisContext::DeducedTemplateArgumentSubstitution,
PointOfInstantiation, InstantiationRange, PartialSpec, nullptr,
TemplateArgs, &DeductionInfo) {}
Sema::InstantiatingTemplate::InstantiatingTemplate(
Sema &SemaRef, SourceLocation PointOfInstantiation, ParmVarDecl *Param,
ArrayRef<TemplateArgument> TemplateArgs, SourceRange InstantiationRange)
: InstantiatingTemplate(
SemaRef,
CodeSynthesisContext::DefaultFunctionArgumentInstantiation,
PointOfInstantiation, InstantiationRange, Param, nullptr,
TemplateArgs) {}
Sema::InstantiatingTemplate::InstantiatingTemplate(
Sema &SemaRef, SourceLocation PointOfInstantiation, NamedDecl *Template,
NonTypeTemplateParmDecl *Param, ArrayRef<TemplateArgument> TemplateArgs,
SourceRange InstantiationRange)
: InstantiatingTemplate(
SemaRef,
CodeSynthesisContext::PriorTemplateArgumentSubstitution,
PointOfInstantiation, InstantiationRange, Param, Template,
TemplateArgs) {}
Sema::InstantiatingTemplate::InstantiatingTemplate(
Sema &SemaRef, SourceLocation PointOfInstantiation, NamedDecl *Template,
TemplateTemplateParmDecl *Param, ArrayRef<TemplateArgument> TemplateArgs,
SourceRange InstantiationRange)
: InstantiatingTemplate(
SemaRef,
CodeSynthesisContext::PriorTemplateArgumentSubstitution,
PointOfInstantiation, InstantiationRange, Param, Template,
TemplateArgs) {}
Sema::InstantiatingTemplate::InstantiatingTemplate(
Sema &SemaRef, SourceLocation PointOfInstantiation, TemplateDecl *Template,
NamedDecl *Param, ArrayRef<TemplateArgument> TemplateArgs,
SourceRange InstantiationRange)
: InstantiatingTemplate(
SemaRef, CodeSynthesisContext::DefaultTemplateArgumentChecking,
PointOfInstantiation, InstantiationRange, Param, Template,
TemplateArgs) {}
void Sema::pushCodeSynthesisContext(CodeSynthesisContext Ctx) {
Ctx.SavedInNonInstantiationSFINAEContext = InNonInstantiationSFINAEContext;
InNonInstantiationSFINAEContext = false;
CodeSynthesisContexts.push_back(Ctx);
if (!Ctx.isInstantiationRecord())
++NonInstantiationEntries;
}
void Sema::popCodeSynthesisContext() {
auto &Active = CodeSynthesisContexts.back();
if (!Active.isInstantiationRecord()) {
assert(NonInstantiationEntries > 0);
--NonInstantiationEntries;
}
InNonInstantiationSFINAEContext = Active.SavedInNonInstantiationSFINAEContext;
// Name lookup no longer looks in this template's defining module.
assert(CodeSynthesisContexts.size() >=
CodeSynthesisContextLookupModules.size() &&
"forgot to remove a lookup module for a template instantiation");
if (CodeSynthesisContexts.size() ==
CodeSynthesisContextLookupModules.size()) {
if (Module *M = CodeSynthesisContextLookupModules.back())
LookupModulesCache.erase(M);
CodeSynthesisContextLookupModules.pop_back();
}
// If we've left the code synthesis context for the current context stack,
// stop remembering that we've emitted that stack.
if (CodeSynthesisContexts.size() ==
LastEmittedCodeSynthesisContextDepth)
LastEmittedCodeSynthesisContextDepth = 0;
CodeSynthesisContexts.pop_back();
}
void Sema::InstantiatingTemplate::Clear() {
if (!Invalid) {
if (!AlreadyInstantiating) {
auto &Active = SemaRef.CodeSynthesisContexts.back();
SemaRef.InstantiatingSpecializations.erase(
std::make_pair(Active.Entity, Active.Kind));
}
atTemplateEnd(SemaRef.TemplateInstCallbacks, SemaRef,
SemaRef.CodeSynthesisContexts.back());
SemaRef.popCodeSynthesisContext();
Invalid = true;
}
}
bool Sema::InstantiatingTemplate::CheckInstantiationDepth(
SourceLocation PointOfInstantiation,
SourceRange InstantiationRange) {
assert(SemaRef.NonInstantiationEntries <=
SemaRef.CodeSynthesisContexts.size());
if ((SemaRef.CodeSynthesisContexts.size() -
SemaRef.NonInstantiationEntries)
<= SemaRef.getLangOpts().InstantiationDepth)
return false;
SemaRef.Diag(PointOfInstantiation,
diag::err_template_recursion_depth_exceeded)
<< SemaRef.getLangOpts().InstantiationDepth
<< InstantiationRange;
SemaRef.Diag(PointOfInstantiation, diag::note_template_recursion_depth)
<< SemaRef.getLangOpts().InstantiationDepth;
return true;
}
/// Prints the current instantiation stack through a series of
/// notes.
void Sema::PrintInstantiationStack() {
// Determine which template instantiations to skip, if any.
unsigned SkipStart = CodeSynthesisContexts.size(), SkipEnd = SkipStart;
unsigned Limit = Diags.getTemplateBacktraceLimit();
if (Limit && Limit < CodeSynthesisContexts.size()) {
SkipStart = Limit / 2 + Limit % 2;
SkipEnd = CodeSynthesisContexts.size() - Limit / 2;
}
// FIXME: In all of these cases, we need to show the template arguments
unsigned InstantiationIdx = 0;
for (SmallVectorImpl<CodeSynthesisContext>::reverse_iterator
Active = CodeSynthesisContexts.rbegin(),
ActiveEnd = CodeSynthesisContexts.rend();
Active != ActiveEnd;
++Active, ++InstantiationIdx) {
// Skip this instantiation?
if (InstantiationIdx >= SkipStart && InstantiationIdx < SkipEnd) {
if (InstantiationIdx == SkipStart) {
// Note that we're skipping instantiations.
Diags.Report(Active->PointOfInstantiation,
diag::note_instantiation_contexts_suppressed)
<< unsigned(CodeSynthesisContexts.size() - Limit);
}
continue;
}
switch (Active->Kind) {
case CodeSynthesisContext::TemplateInstantiation: {
Decl *D = 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(Active->PointOfInstantiation, DiagID)
<< 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(Active->PointOfInstantiation, DiagID)
<< Function
<< Active->InstantiationRange;
} else if (VarDecl *VD = dyn_cast<VarDecl>(D)) {
Diags.Report(Active->PointOfInstantiation,
VD->isStaticDataMember()?
diag::note_template_static_data_member_def_here
: diag::note_template_variable_def_here)
<< VD
<< Active->InstantiationRange;
} else if (EnumDecl *ED = dyn_cast<EnumDecl>(D)) {
Diags.Report(Active->PointOfInstantiation,
diag::note_template_enum_def_here)
<< ED
<< Active->InstantiationRange;
} else if (FieldDecl *FD = dyn_cast<FieldDecl>(D)) {
Diags.Report(Active->PointOfInstantiation,
diag::note_template_nsdmi_here)
<< FD << Active->InstantiationRange;
} else {
Diags.Report(Active->PointOfInstantiation,
diag::note_template_type_alias_instantiation_here)
<< cast<TypeAliasTemplateDecl>(D)
<< Active->InstantiationRange;
}
break;
}
case CodeSynthesisContext::DefaultTemplateArgumentInstantiation: {
TemplateDecl *Template = cast<TemplateDecl>(Active->Template);
SmallVector<char, 128> TemplateArgsStr;
llvm::raw_svector_ostream OS(TemplateArgsStr);
Template->printName(OS);
printTemplateArgumentList(OS, Active->template_arguments(),
getPrintingPolicy());
Diags.Report(Active->PointOfInstantiation,
diag::note_default_arg_instantiation_here)
<< OS.str()
<< Active->InstantiationRange;
break;
}
case CodeSynthesisContext::ExplicitTemplateArgumentSubstitution: {
FunctionTemplateDecl *FnTmpl = cast<FunctionTemplateDecl>(Active->Entity);
Diags.Report(Active->PointOfInstantiation,
diag::note_explicit_template_arg_substitution_here)
<< FnTmpl
<< getTemplateArgumentBindingsText(FnTmpl->getTemplateParameters(),
Active->TemplateArgs,
Active->NumTemplateArgs)
<< Active->InstantiationRange;
break;
}
case CodeSynthesisContext::DeducedTemplateArgumentSubstitution: {
if (FunctionTemplateDecl *FnTmpl =
dyn_cast<FunctionTemplateDecl>(Active->Entity)) {
Diags.Report(Active->PointOfInstantiation,
diag::note_function_template_deduction_instantiation_here)
<< FnTmpl
<< getTemplateArgumentBindingsText(FnTmpl->getTemplateParameters(),
Active->TemplateArgs,
Active->NumTemplateArgs)
<< Active->InstantiationRange;
} else {
bool IsVar = isa<VarTemplateDecl>(Active->Entity) ||
isa<VarTemplateSpecializationDecl>(Active->Entity);
bool IsTemplate = false;
TemplateParameterList *Params;
if (auto *D = dyn_cast<TemplateDecl>(Active->Entity)) {
IsTemplate = true;
Params = D->getTemplateParameters();
} else if (auto *D = dyn_cast<ClassTemplatePartialSpecializationDecl>(
Active->Entity)) {
Params = D->getTemplateParameters();
} else if (auto *D = dyn_cast<VarTemplatePartialSpecializationDecl>(
Active->Entity)) {
Params = D->getTemplateParameters();
} else {
llvm_unreachable("unexpected template kind");
}
Diags.Report(Active->PointOfInstantiation,
diag::note_deduced_template_arg_substitution_here)
<< IsVar << IsTemplate << cast<NamedDecl>(Active->Entity)
<< getTemplateArgumentBindingsText(Params, Active->TemplateArgs,
Active->NumTemplateArgs)
<< Active->InstantiationRange;
}
break;
}
case CodeSynthesisContext::DefaultFunctionArgumentInstantiation: {
ParmVarDecl *Param = cast<ParmVarDecl>(Active->Entity);
FunctionDecl *FD = cast<FunctionDecl>(Param->getDeclContext());
SmallVector<char, 128> TemplateArgsStr;
llvm::raw_svector_ostream OS(TemplateArgsStr);
FD->printName(OS);
printTemplateArgumentList(OS, Active->template_arguments(),
getPrintingPolicy());
Diags.Report(Active->PointOfInstantiation,
diag::note_default_function_arg_instantiation_here)
<< OS.str()
<< Active->InstantiationRange;
break;
}
case CodeSynthesisContext::PriorTemplateArgumentSubstitution: {
NamedDecl *Parm = cast<NamedDecl>(Active->Entity);
std::string Name;
if (!Parm->getName().empty())
Name = std::string(" '") + Parm->getName().str() + "'";
TemplateParameterList *TemplateParams = nullptr;
if (TemplateDecl *Template = dyn_cast<TemplateDecl>(Active->Template))
TemplateParams = Template->getTemplateParameters();
else
TemplateParams =
cast<ClassTemplatePartialSpecializationDecl>(Active->Template)
->getTemplateParameters();
Diags.Report(Active->PointOfInstantiation,
diag::note_prior_template_arg_substitution)
<< isa<TemplateTemplateParmDecl>(Parm)
<< Name
<< getTemplateArgumentBindingsText(TemplateParams,
Active->TemplateArgs,
Active->NumTemplateArgs)
<< Active->InstantiationRange;
break;
}
case CodeSynthesisContext::DefaultTemplateArgumentChecking: {
TemplateParameterList *TemplateParams = nullptr;
if (TemplateDecl *Template = dyn_cast<TemplateDecl>(Active->Template))
TemplateParams = Template->getTemplateParameters();
else
TemplateParams =
cast<ClassTemplatePartialSpecializationDecl>(Active->Template)
->getTemplateParameters();
Diags.Report(Active->PointOfInstantiation,
diag::note_template_default_arg_checking)
<< getTemplateArgumentBindingsText(TemplateParams,
Active->TemplateArgs,
Active->NumTemplateArgs)
<< Active->InstantiationRange;
break;
}
case CodeSynthesisContext::ExceptionSpecEvaluation:
Diags.Report(Active->PointOfInstantiation,
diag::note_evaluating_exception_spec_here)
<< cast<FunctionDecl>(Active->Entity);
break;
case CodeSynthesisContext::ExceptionSpecInstantiation:
Diags.Report(Active->PointOfInstantiation,
diag::note_template_exception_spec_instantiation_here)
<< cast<FunctionDecl>(Active->Entity)
<< Active->InstantiationRange;
break;
case CodeSynthesisContext::DeclaringSpecialMember:
Diags.Report(Active->PointOfInstantiation,
diag::note_in_declaration_of_implicit_special_member)
<< cast<CXXRecordDecl>(Active->Entity) << Active->SpecialMember;
break;
case CodeSynthesisContext::DefiningSynthesizedFunction: {
// FIXME: For synthesized members other than special members, produce a note.
auto *MD = dyn_cast<CXXMethodDecl>(Active->Entity);
auto CSM = MD ? getSpecialMember(MD) : CXXInvalid;
if (CSM != CXXInvalid) {
Diags.Report(Active->PointOfInstantiation,
diag::note_member_synthesized_at)
<< CSM << Context.getTagDeclType(MD->getParent());
}
break;
}
case CodeSynthesisContext::Memoization:
break;
}
}
}
Optional<TemplateDeductionInfo *> Sema::isSFINAEContext() const {
if (InNonInstantiationSFINAEContext)
return Optional<TemplateDeductionInfo *>(nullptr);
for (SmallVectorImpl<CodeSynthesisContext>::const_reverse_iterator
Active = CodeSynthesisContexts.rbegin(),
ActiveEnd = CodeSynthesisContexts.rend();
Active != ActiveEnd;
++Active)
{
switch (Active->Kind) {
case CodeSynthesisContext::TemplateInstantiation:
// An instantiation of an alias template may or may not be a SFINAE
// context, depending on what else is on the stack.
if (isa<TypeAliasTemplateDecl>(Active->Entity))
break;
LLVM_FALLTHROUGH;
case CodeSynthesisContext::DefaultFunctionArgumentInstantiation:
case CodeSynthesisContext::ExceptionSpecInstantiation:
// This is a template instantiation, so there is no SFINAE.
return None;
case CodeSynthesisContext::DefaultTemplateArgumentInstantiation:
case CodeSynthesisContext::PriorTemplateArgumentSubstitution:
case CodeSynthesisContext::DefaultTemplateArgumentChecking:
// A default template argument instantiation and substitution into
// template parameters with arguments for prior parameters may or may
// not be a SFINAE context; look further up the stack.
break;
case CodeSynthesisContext::ExplicitTemplateArgumentSubstitution:
case CodeSynthesisContext::DeducedTemplateArgumentSubstitution:
// We're either substitution explicitly-specified template arguments
// or deduced template arguments, so SFINAE applies.
assert(Active->DeductionInfo && "Missing deduction info pointer");
return Active->DeductionInfo;
case CodeSynthesisContext::DeclaringSpecialMember:
case CodeSynthesisContext::DefiningSynthesizedFunction:
// This happens in a context unrelated to template instantiation, so
// there is no SFINAE.
return None;
case CodeSynthesisContext::ExceptionSpecEvaluation:
// FIXME: This should not be treated as a SFINAE context, because
// we will cache an incorrect exception specification. However, clang
// bootstrap relies this! See PR31692.
break;
case CodeSynthesisContext::Memoization:
break;
}
// The inner context was transparent for SFINAE. If it occurred within a
// non-instantiation SFINAE context, then SFINAE applies.
if (Active->SavedInNonInstantiationSFINAEContext)
return Optional<TemplateDeductionInfo *>(nullptr);
}
return None;
}
//===----------------------------------------------------------------------===/
// Template Instantiation for Types
//===----------------------------------------------------------------------===/
namespace {
class 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) { }
/// 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);
/// Returns the location of the entity being instantiated, if known.
SourceLocation getBaseLocation() { return Loc; }
/// Returns the name of the entity being instantiated, if any.
DeclarationName getBaseEntity() { return Entity; }
/// Sets the "base" location and entity when that
/// information is known based on another transformation.
void setBase(SourceLocation Loc, DeclarationName Entity) {
this->Loc = Loc;
this->Entity = Entity;
}
bool TryExpandParameterPacks(SourceLocation EllipsisLoc,
SourceRange PatternRange,
ArrayRef<UnexpandedParameterPack> Unexpanded,
bool &ShouldExpand, bool &RetainExpansion,
Optional<unsigned> &NumExpansions) {
return getSema().CheckParameterPacksForExpansion(EllipsisLoc,
PatternRange, Unexpanded,
TemplateArgs,
ShouldExpand,
RetainExpansion,
NumExpansions);
}
void ExpandingFunctionParameterPack(ParmVarDecl *Pack) {
SemaRef.CurrentInstantiationScope->MakeInstantiatedLocalArgPack(Pack);
}
TemplateArgument ForgetPartiallySubstitutedPack() {
TemplateArgument Result;
if (NamedDecl *PartialPack
= SemaRef.CurrentInstantiationScope->getPartiallySubstitutedPack()){
MultiLevelTemplateArgumentList &TemplateArgs
= const_cast<MultiLevelTemplateArgumentList &>(this->TemplateArgs);
unsigned Depth, Index;
std::tie(Depth, Index) = getDepthAndIndex(PartialPack);
if (TemplateArgs.hasTemplateArgument(Depth, Index)) {
Result = TemplateArgs(Depth, Index);
TemplateArgs.setArgument(Depth, Index, TemplateArgument());
}
}
return Result;
}
void RememberPartiallySubstitutedPack(TemplateArgument Arg) {
if (Arg.isNull())
return;
if (NamedDecl *PartialPack
= SemaRef.CurrentInstantiationScope->getPartiallySubstitutedPack()){
MultiLevelTemplateArgumentList &TemplateArgs
= const_cast<MultiLevelTemplateArgumentList &>(this->TemplateArgs);
unsigned Depth, Index;
std::tie(Depth, Index) = getDepthAndIndex(PartialPack);
TemplateArgs.setArgument(Depth, Index, Arg);
}
}
/// Transform the given declaration by instantiating a reference to
/// this declaration.
Decl *TransformDecl(SourceLocation Loc, Decl *D);
void transformAttrs(Decl *Old, Decl *New) {
SemaRef.InstantiateAttrs(TemplateArgs, Old, New);
}
void transformedLocalDecl(Decl *Old, Decl *New) {
// If we've instantiated the call operator of a lambda or the call
// operator template of a generic lambda, update the "instantiation of"
// information.
auto *NewMD = dyn_cast<CXXMethodDecl>(New);
if (NewMD && isLambdaCallOperator(NewMD)) {
auto *OldMD = dyn_cast<CXXMethodDecl>(Old);
if (auto *NewTD = NewMD->getDescribedFunctionTemplate())
NewTD->setInstantiatedFromMemberTemplate(
OldMD->getDescribedFunctionTemplate());
else
NewMD->setInstantiationOfMemberFunction(OldMD,
TSK_ImplicitInstantiation);
}
SemaRef.CurrentInstantiationScope->InstantiatedLocal(Old, New);
// We recreated a local declaration, but not by instantiating it. There
// may be pending dependent diagnostics to produce.
if (auto *DC = dyn_cast<DeclContext>(Old))
SemaRef.PerformDependentDiagnostics(DC, TemplateArgs);
}
/// Transform the definition of the given declaration by
/// instantiating it.
Decl *TransformDefinition(SourceLocation Loc, Decl *D);
/// Transform the first qualifier within a scope by instantiating the
/// declaration.
NamedDecl *TransformFirstQualifierInScope(NamedDecl *D, SourceLocation Loc);
/// Rebuild the exception declaration and register the declaration
/// as an instantiated local.
VarDecl *RebuildExceptionDecl(VarDecl *ExceptionDecl,
TypeSourceInfo *Declarator,
SourceLocation StartLoc,
SourceLocation NameLoc,
IdentifierInfo *Name);
/// Rebuild the Objective-C exception declaration and register the
/// declaration as an instantiated local.
VarDecl *RebuildObjCExceptionDecl(VarDecl *ExceptionDecl,
TypeSourceInfo *TSInfo, QualType T);
/// Check for tag mismatches when instantiating an
/// elaborated type.
QualType RebuildElaboratedType(SourceLocation KeywordLoc,
ElaboratedTypeKeyword Keyword,
NestedNameSpecifierLoc QualifierLoc,
QualType T);
TemplateName
TransformTemplateName(CXXScopeSpec &SS, TemplateName Name,
SourceLocation NameLoc,
QualType ObjectType = QualType(),
NamedDecl *FirstQualifierInScope = nullptr,
bool AllowInjectedClassName = false);
const LoopHintAttr *TransformLoopHintAttr(const LoopHintAttr *LH);
ExprResult TransformPredefinedExpr(PredefinedExpr *E);
ExprResult TransformDeclRefExpr(DeclRefExpr *E);
ExprResult TransformCXXDefaultArgExpr(CXXDefaultArgExpr *E);
ExprResult TransformTemplateParmRefExpr(DeclRefExpr *E,
NonTypeTemplateParmDecl *D);
ExprResult TransformSubstNonTypeTemplateParmPackExpr(
SubstNonTypeTemplateParmPackExpr *E);
/// Rebuild a DeclRefExpr for a ParmVarDecl reference.
ExprResult RebuildParmVarDeclRefExpr(ParmVarDecl *PD, SourceLocation Loc);
/// Transform a reference to a function parameter pack.
ExprResult TransformFunctionParmPackRefExpr(DeclRefExpr *E,
ParmVarDecl *PD);
/// Transform a FunctionParmPackExpr which was built when we couldn't
/// expand a function parameter pack reference which refers to an expanded
/// pack.
ExprResult TransformFunctionParmPackExpr(FunctionParmPackExpr *E);
QualType TransformFunctionProtoType(TypeLocBuilder &TLB,
FunctionProtoTypeLoc TL) {
// Call the base version; it will forward to our overridden version below.
return inherited::TransformFunctionProtoType(TLB, TL);
}
template<typename Fn>
QualType TransformFunctionProtoType(TypeLocBuilder &TLB,
FunctionProtoTypeLoc TL,
CXXRecordDecl *ThisContext,
Qualifiers ThisTypeQuals,
Fn TransformExceptionSpec);
ParmVarDecl *TransformFunctionTypeParam(ParmVarDecl *OldParm,
int indexAdjustment,
Optional<unsigned> NumExpansions,
bool ExpectParameterPack);
/// Transforms a template type parameter type by performing
/// substitution of the corresponding template type argument.
QualType TransformTemplateTypeParmType(TypeLocBuilder &TLB,
TemplateTypeParmTypeLoc TL);
/// Transforms an already-substituted template type parameter pack
/// into either itself (if we aren't substituting into its pack expansion)
/// or the appropriate substituted argument.
QualType TransformSubstTemplateTypeParmPackType(TypeLocBuilder &TLB,
SubstTemplateTypeParmPackTypeLoc TL);
ExprResult TransformLambdaExpr(LambdaExpr *E) {
LocalInstantiationScope Scope(SemaRef, /*CombineWithOuterScope=*/true);
return TreeTransform<TemplateInstantiator>::TransformLambdaExpr(E);
}
TemplateParameterList *TransformTemplateParameterList(
TemplateParameterList *OrigTPL) {
if (!OrigTPL || !OrigTPL->size()) return OrigTPL;
DeclContext *Owner = OrigTPL->getParam(0)->getDeclContext();
TemplateDeclInstantiator DeclInstantiator(getSema(),
/* DeclContext *Owner */ Owner, TemplateArgs);
return DeclInstantiator.SubstTemplateParams(OrigTPL);
}
private:
ExprResult transformNonTypeTemplateParmRef(NonTypeTemplateParmDecl *parm,
SourceLocation loc,
TemplateArgument arg);
};
}
bool TemplateInstantiator::AlreadyTransformed(QualType T) {
if (T.isNull())
return true;
if (T->isInstantiationDependentType() || T->isVariablyModifiedType())
return false;
getSema().MarkDeclarationsReferencedInType(Loc, T);
return true;
}
static TemplateArgument
getPackSubstitutedTemplateArgument(Sema &S, TemplateArgument Arg) {
assert(S.ArgumentPackSubstitutionIndex >= 0);
assert(S.ArgumentPackSubstitutionIndex < (int)Arg.pack_size());
Arg = Arg.pack_begin()[S.ArgumentPackSubstitutionIndex];
if (Arg.isPackExpansion())
Arg = Arg.getPackExpansionPattern();
return Arg;
}
Decl *TemplateInstantiator::TransformDecl(SourceLocation Loc, Decl *D) {
if (!D)
return nullptr;
if (TemplateTemplateParmDecl *TTP = dyn_cast<TemplateTemplateParmDecl>(D)) {
if (TTP->getDepth() < TemplateArgs.getNumLevels()) {
// 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;
TemplateArgument Arg = TemplateArgs(TTP->getDepth(), TTP->getPosition());
if (TTP->isParameterPack()) {
assert(Arg.getKind() == TemplateArgument::Pack &&
"Missing argument pack");
Arg = getPackSubstitutedTemplateArgument(getSema(), Arg);
}
TemplateName Template = Arg.getAsTemplate().getNameToSubstitute();
assert(!Template.isNull() && Template.getAsTemplateDecl() &&
"Wrong kind of template template argument");
return Template.getAsTemplateDecl();
}
// Fall through to find the instantiated declaration for this template
// template parameter.
}
return SemaRef.FindInstantiatedDecl(Loc, cast<NamedDecl>(D), TemplateArgs);
}
Decl *TemplateInstantiator::TransformDefinition(SourceLocation Loc, Decl *D) {
Decl *Inst = getSema().SubstDecl(D, getSema().CurContext, TemplateArgs);
if (!Inst)
return nullptr;
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()) {
// FIXME: This needs testing w/ member access expressions.
TemplateArgument Arg = TemplateArgs(TTP->getDepth(), TTP->getIndex());
if (TTP->isParameterPack()) {
assert(Arg.getKind() == TemplateArgument::Pack &&
"Missing argument pack");
if (getSema().ArgumentPackSubstitutionIndex == -1)
return nullptr;
Arg = getPackSubstitutedTemplateArgument(getSema(), Arg);
}
QualType T = Arg.getAsType();
if (T.isNull())
return cast_or_null<NamedDecl>(TransformDecl(Loc, 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 nullptr;
}
}
return cast_or_null<NamedDecl>(TransformDecl(Loc, D));
}
VarDecl *
TemplateInstantiator::RebuildExceptionDecl(VarDecl *ExceptionDecl,
TypeSourceInfo *Declarator,
SourceLocation StartLoc,
SourceLocation NameLoc,
IdentifierInfo *Name) {
VarDecl *Var = inherited::RebuildExceptionDecl(ExceptionDecl, Declarator,
StartLoc, NameLoc, Name);
if (Var)
getSema().CurrentInstantiationScope->InstantiatedLocal(ExceptionDecl, Var);
return Var;
}
VarDecl *TemplateInstantiator::RebuildObjCExceptionDecl(VarDecl *ExceptionDecl,
TypeSourceInfo *TSInfo,
QualType T) {
VarDecl *Var = inherited::RebuildObjCExceptionDecl(ExceptionDecl, TSInfo, T);
if (Var)
getSema().CurrentInstantiationScope->InstantiatedLocal(ExceptionDecl, Var);
return Var;
}
QualType
TemplateInstantiator::RebuildElaboratedType(SourceLocation KeywordLoc,
ElaboratedTypeKeyword Keyword,
NestedNameSpecifierLoc QualifierLoc,
QualType T) {
if (const TagType *TT = T->getAs<TagType>()) {
TagDecl* TD = TT->getDecl();
SourceLocation TagLocation = KeywordLoc;
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 (Id && Keyword != ETK_None && Keyword != ETK_Typename) {
TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForKeyword(Keyword);
if (!SemaRef.isAcceptableTagRedeclaration(TD, Kind, /*isDefinition*/false,
TagLocation, Id)) {
SemaRef.Diag(TagLocation, diag::err_use_with_wrong_tag)
<< Id
<< FixItHint::CreateReplacement(SourceRange(TagLocation),
TD->getKindName());
SemaRef.Diag(TD->getLocation(), diag::note_previous_use);
}
}
}
return TreeTransform<TemplateInstantiator>::RebuildElaboratedType(KeywordLoc,
Keyword,
QualifierLoc,
T);
}
TemplateName TemplateInstantiator::TransformTemplateName(
CXXScopeSpec &SS, TemplateName Name, SourceLocation NameLoc,
QualType ObjectType, NamedDecl *FirstQualifierInScope,
bool AllowInjectedClassName) {
if (TemplateTemplateParmDecl *TTP
= dyn_cast_or_null<TemplateTemplateParmDecl>(Name.getAsTemplateDecl())) {
if (TTP->getDepth() < TemplateArgs.getNumLevels()) {
// 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 Name;
TemplateArgument Arg = TemplateArgs(TTP->getDepth(), TTP->getPosition());
if (TTP->isParameterPack()) {
assert(Arg.getKind() == TemplateArgument::Pack &&
"Missing argument pack");
if (getSema().ArgumentPackSubstitutionIndex == -1) {
// We have the template argument pack to substitute, but we're not
// actually expanding the enclosing pack expansion yet. So, just
// keep the entire argument pack.
return getSema().Context.getSubstTemplateTemplateParmPack(TTP, Arg);
}
Arg = getPackSubstitutedTemplateArgument(getSema(), Arg);
}
TemplateName Template = Arg.getAsTemplate().getNameToSubstitute();
assert(!Template.isNull() && "Null template template argument");
assert(!Template.getAsQualifiedTemplateName() &&
"template decl to substitute is qualified?");
Template = getSema().Context.getSubstTemplateTemplateParm(TTP, Template);
return Template;
}
}
if (SubstTemplateTemplateParmPackStorage *SubstPack
= Name.getAsSubstTemplateTemplateParmPack()) {
if (getSema().ArgumentPackSubstitutionIndex == -1)
return Name;
TemplateArgument Arg = SubstPack->getArgumentPack();
Arg = getPackSubstitutedTemplateArgument(getSema(), Arg);
return Arg.getAsTemplate().getNameToSubstitute();
}
return inherited::TransformTemplateName(SS, Name, NameLoc, ObjectType,
FirstQualifierInScope,
AllowInjectedClassName);
}
ExprResult
TemplateInstantiator::TransformPredefinedExpr(PredefinedExpr *E) {
if (!E->isTypeDependent())
return E;
return getSema().BuildPredefinedExpr(E->getLocation(), E->getIdentKind());
}
ExprResult
TemplateInstantiator::TransformTemplateParmRefExpr(DeclRefExpr *E,
NonTypeTemplateParmDecl *NTTP) {
// 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 E;
TemplateArgument Arg = TemplateArgs(NTTP->getDepth(), NTTP->getPosition());
if (TemplateArgs.getNumLevels() != TemplateArgs.getNumSubstitutedLevels()) {
// We're performing a partial substitution, so the substituted argument
// could be dependent. As a result we can't create a SubstNonType*Expr
// node now, since that represents a fully-substituted argument.
// FIXME: We should have some AST representation for this.
if (Arg.getKind() == TemplateArgument::Pack) {
// FIXME: This won't work for alias templates.
assert(Arg.pack_size() == 1 && Arg.pack_begin()->isPackExpansion() &&
"unexpected pack arguments in partial substitution");
Arg = Arg.pack_begin()->getPackExpansionPattern();
}
assert(Arg.getKind() == TemplateArgument::Expression &&
"unexpected nontype template argument kind in partial substitution");
return Arg.getAsExpr();
}
if (NTTP->isParameterPack()) {
assert(Arg.getKind() == TemplateArgument::Pack &&
"Missing argument pack");
if (getSema().ArgumentPackSubstitutionIndex == -1) {
// We have an argument pack, but we can't select a particular argument
// out of it yet. Therefore, we'll build an expression to hold on to that
// argument pack.
QualType TargetType = SemaRef.SubstType(NTTP->getType(), TemplateArgs,
E->getLocation(),
NTTP->getDeclName());
if (TargetType.isNull())
return ExprError();
return new (SemaRef.Context) SubstNonTypeTemplateParmPackExpr(
TargetType.getNonLValueExprType(SemaRef.Context),
TargetType->isReferenceType() ? VK_LValue : VK_RValue, NTTP,
E->getLocation(), Arg);
}
Arg = getPackSubstitutedTemplateArgument(getSema(), Arg);
}
return transformNonTypeTemplateParmRef(NTTP, E->getLocation(), Arg);
}
const LoopHintAttr *
TemplateInstantiator::TransformLoopHintAttr(const LoopHintAttr *LH) {
Expr *TransformedExpr = getDerived().TransformExpr(LH->getValue()).get();
if (TransformedExpr == LH->getValue())
return LH;
// Generate error if there is a problem with the value.
if (getSema().CheckLoopHintExpr(TransformedExpr, LH->getLocation()))
return LH;
// Create new LoopHintValueAttr with integral expression in place of the
// non-type template parameter.
return LoopHintAttr::CreateImplicit(
getSema().Context, LH->getSemanticSpelling(), LH->getOption(),
LH->getState(), TransformedExpr, LH->getRange());
}
ExprResult TemplateInstantiator::transformNonTypeTemplateParmRef(
NonTypeTemplateParmDecl *parm,
SourceLocation loc,
TemplateArgument arg) {
ExprResult result;
QualType type;
// The template argument itself might be an expression, in which
// case we just return that expression.
if (arg.getKind() == TemplateArgument::Expression) {
Expr *argExpr = arg.getAsExpr();
result = argExpr;
type = argExpr->getType();
} else if (arg.getKind() == TemplateArgument::Declaration ||
arg.getKind() == TemplateArgument::NullPtr) {
ValueDecl *VD;
if (arg.getKind() == TemplateArgument::Declaration) {
VD = arg.getAsDecl();
// Find the instantiation of the template argument. This is
// required for nested templates.
VD = cast_or_null<ValueDecl>(
getSema().FindInstantiatedDecl(loc, VD, TemplateArgs));
if (!VD)
return ExprError();
} else {
// Propagate NULL template argument.
VD = nullptr;
}
// Derive the type we want the substituted decl to have. This had
// better be non-dependent, or these checks will have serious problems.
if (parm->isExpandedParameterPack()) {
type = parm->getExpansionType(SemaRef.ArgumentPackSubstitutionIndex);
} else if (parm->isParameterPack() &&
isa<PackExpansionType>(parm->getType())) {
type = SemaRef.SubstType(
cast<PackExpansionType>(parm->getType())->getPattern(),
TemplateArgs, loc, parm->getDeclName());
} else {
type = SemaRef.SubstType(VD ? arg.getParamTypeForDecl() : arg.getNullPtrType(),
TemplateArgs, loc, parm->getDeclName());
}
assert(!type.isNull() && "type substitution failed for param type");
assert(!type->isDependentType() && "param type still dependent");
result = SemaRef.BuildExpressionFromDeclTemplateArgument(arg, type, loc);
if (!result.isInvalid()) type = result.get()->getType();
} else {
result = SemaRef.BuildExpressionFromIntegralTemplateArgument(arg, loc);
// Note that this type can be different from the type of 'result',
// e.g. if it's an enum type.
type = arg.getIntegralType();
}
if (result.isInvalid()) return ExprError();
Expr *resultExpr = result.get();
return new (SemaRef.Context) SubstNonTypeTemplateParmExpr(
type, resultExpr->getValueKind(), loc, parm, resultExpr);
}
ExprResult
TemplateInstantiator::TransformSubstNonTypeTemplateParmPackExpr(
SubstNonTypeTemplateParmPackExpr *E) {
if (getSema().ArgumentPackSubstitutionIndex == -1) {
// We aren't expanding the parameter pack, so just return ourselves.
return E;
}
TemplateArgument Arg = E->getArgumentPack();
Arg = getPackSubstitutedTemplateArgument(getSema(), Arg);
return transformNonTypeTemplateParmRef(E->getParameterPack(),
E->getParameterPackLocation(),
Arg);
}
ExprResult
TemplateInstantiator::RebuildParmVarDeclRefExpr(ParmVarDecl *PD,
SourceLocation Loc) {
DeclarationNameInfo NameInfo(PD->getDeclName(), Loc);
return getSema().BuildDeclarationNameExpr(CXXScopeSpec(), NameInfo, PD);
}
ExprResult
TemplateInstantiator::TransformFunctionParmPackExpr(FunctionParmPackExpr *E) {
if (getSema().ArgumentPackSubstitutionIndex != -1) {
// We can expand this parameter pack now.
ParmVarDecl *D = E->getExpansion(getSema().ArgumentPackSubstitutionIndex);
ValueDecl *VD = cast_or_null<ValueDecl>(TransformDecl(E->getExprLoc(), D));
if (!VD)
return ExprError();
return RebuildParmVarDeclRefExpr(cast<ParmVarDecl>(VD), E->getExprLoc());
}
QualType T = TransformType(E->getType());
if (T.isNull())
return ExprError();
// Transform each of the parameter expansions into the corresponding
// parameters in the instantiation of the function decl.
SmallVector<ParmVarDecl *, 8> Parms;
Parms.reserve(E->getNumExpansions());
for (FunctionParmPackExpr::iterator I = E->begin(), End = E->end();
I != End; ++I) {
ParmVarDecl *D =
cast_or_null<ParmVarDecl>(TransformDecl(E->getExprLoc(), *I));
if (!D)
return ExprError();
Parms.push_back(D);
}
return FunctionParmPackExpr::Create(getSema().Context, T,
E->getParameterPack(),
E->getParameterPackLocation(), Parms);
}
ExprResult
TemplateInstantiator::TransformFunctionParmPackRefExpr(DeclRefExpr *E,
ParmVarDecl *PD) {
typedef LocalInstantiationScope::DeclArgumentPack DeclArgumentPack;
llvm::PointerUnion<Decl *, DeclArgumentPack *> *Found
= getSema().CurrentInstantiationScope->findInstantiationOf(PD);
assert(Found && "no instantiation for parameter pack");
Decl *TransformedDecl;
if (DeclArgumentPack *Pack = Found->dyn_cast<DeclArgumentPack *>()) {
// If this is a reference to a function parameter pack which we can
// substitute but can't yet expand, build a FunctionParmPackExpr for it.
if (getSema().ArgumentPackSubstitutionIndex == -1) {
QualType T = TransformType(E->getType());
if (T.isNull())
return ExprError();
return FunctionParmPackExpr::Create(getSema().Context, T, PD,
E->getExprLoc(), *Pack);
}
TransformedDecl = (*Pack)[getSema().ArgumentPackSubstitutionIndex];
} else {
TransformedDecl = Found->get<Decl*>();
}
// We have either an unexpanded pack or a specific expansion.
return RebuildParmVarDeclRefExpr(cast<ParmVarDecl>(TransformedDecl),
E->getExprLoc());
}
ExprResult
TemplateInstantiator::TransformDeclRefExpr(DeclRefExpr *E) {
NamedDecl *D = E->getDecl();
// Handle references to non-type template parameters and non-type template
// parameter packs.
if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(D)) {
if (NTTP->getDepth() < TemplateArgs.getNumLevels())
return TransformTemplateParmRefExpr(E, NTTP);
// We have a non-type template parameter that isn't fully substituted;
// FindInstantiatedDecl will find it in the local instantiation scope.
}
// Handle references to function parameter packs.
if (ParmVarDecl *PD = dyn_cast<ParmVarDecl>(D))
if (PD->isParameterPack())
return TransformFunctionParmPackRefExpr(E, PD);
return TreeTransform<TemplateInstantiator>::TransformDeclRefExpr(E);
}
ExprResult TemplateInstantiator::TransformCXXDefaultArgExpr(
CXXDefaultArgExpr *E) {
assert(!cast<FunctionDecl>(E->getParam()->getDeclContext())->
getDescribedFunctionTemplate() &&
"Default arg expressions are never formed in dependent cases.");
return SemaRef.BuildCXXDefaultArgExpr(E->getUsedLocation(),
cast<FunctionDecl>(E->getParam()->getDeclContext()),
E->getParam());
}
template<typename Fn>
QualType TemplateInstantiator::TransformFunctionProtoType(TypeLocBuilder &TLB,
FunctionProtoTypeLoc TL,
CXXRecordDecl *ThisContext,
Qualifiers ThisTypeQuals,
Fn TransformExceptionSpec) {
// We need a local instantiation scope for this function prototype.
LocalInstantiationScope Scope(SemaRef, /*CombineWithOuterScope=*/true);
return inherited::TransformFunctionProtoType(
TLB, TL, ThisContext, ThisTypeQuals, TransformExceptionSpec);
}
ParmVarDecl *
TemplateInstantiator::TransformFunctionTypeParam(ParmVarDecl *OldParm,
int indexAdjustment,
Optional<unsigned> NumExpansions,
bool ExpectParameterPack) {
return SemaRef.SubstParmVarDecl(OldParm, TemplateArgs, indexAdjustment,
NumExpansions, ExpectParameterPack);
}
QualType
TemplateInstantiator::TransformTemplateTypeParmType(TypeLocBuilder &TLB,
TemplateTypeParmTypeLoc TL) {
const 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();
}
TemplateArgument Arg = TemplateArgs(T->getDepth(), T->getIndex());
if (T->isParameterPack()) {
assert(Arg.getKind() == TemplateArgument::Pack &&
"Missing argument pack");
if (getSema().ArgumentPackSubstitutionIndex == -1) {
// We have the template argument pack, but we're not expanding the
// enclosing pack expansion yet. Just save the template argument
// pack for later substitution.
QualType Result
= getSema().Context.getSubstTemplateTypeParmPackType(T, Arg);
SubstTemplateTypeParmPackTypeLoc NewTL
= TLB.push<SubstTemplateTypeParmPackTypeLoc>(Result);
NewTL.setNameLoc(TL.getNameLoc());
return Result;
}
Arg = getPackSubstitutedTemplateArgument(getSema(), Arg);
}
assert(Arg.getKind() == TemplateArgument::Type &&
"Template argument kind mismatch");
QualType Replacement = Arg.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.
TemplateTypeParmDecl *NewTTPDecl = nullptr;
if (TemplateTypeParmDecl *OldTTPDecl = T->getDecl())
NewTTPDecl = cast_or_null<TemplateTypeParmDecl>(
TransformDecl(TL.getNameLoc(), OldTTPDecl));
QualType Result = getSema().Context.getTemplateTypeParmType(
T->getDepth() - TemplateArgs.getNumSubstitutedLevels(), T->getIndex(),
T->isParameterPack(), NewTTPDecl);
TemplateTypeParmTypeLoc NewTL = TLB.push<TemplateTypeParmTypeLoc>(Result);
NewTL.setNameLoc(TL.getNameLoc());
return Result;
}
QualType
TemplateInstantiator::TransformSubstTemplateTypeParmPackType(
TypeLocBuilder &TLB,
SubstTemplateTypeParmPackTypeLoc TL) {
if (getSema().ArgumentPackSubstitutionIndex == -1) {
// We aren't expanding the parameter pack, so just return ourselves.
SubstTemplateTypeParmPackTypeLoc NewTL
= TLB.push<SubstTemplateTypeParmPackTypeLoc>(TL.getType());
NewTL.setNameLoc(TL.getNameLoc());
return TL.getType();
}
TemplateArgument Arg = TL.getTypePtr()->getArgumentPack();
Arg = getPackSubstitutedTemplateArgument(getSema(), Arg);
QualType Result = Arg.getAsType();
Result = getSema().Context.getSubstTemplateTypeParmType(
TL.getTypePtr()->getReplacedParameter(),
Result);
SubstTemplateTypeParmTypeLoc NewTL
= TLB.push<SubstTemplateTypeParmTypeLoc>(Result);
NewTL.setNameLoc(TL.getNameLoc());
return Result;
}
/// 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 Args 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).
///
/// \param AllowDeducedTST Whether a DeducedTemplateSpecializationType is
/// acceptable as the top level type of the result.
///
/// \returns If the instantiation succeeds, the instantiated
/// type. Otherwise, produces diagnostics and returns a NULL type.
TypeSourceInfo *Sema::SubstType(TypeSourceInfo *T,
const MultiLevelTemplateArgumentList &Args,
SourceLocation Loc,
DeclarationName Entity,
bool AllowDeducedTST) {
assert(!CodeSynthesisContexts.empty() &&
"Cannot perform an instantiation without some context on the "
"instantiation stack");
if (!T->getType()->isInstantiationDependentType() &&
!T->getType()->isVariablyModifiedType())
return T;
TemplateInstantiator Instantiator(*this, Args, Loc, Entity);
return AllowDeducedTST ? Instantiator.TransformTypeWithDeducedTST(T)
: Instantiator.TransformType(T);
}
TypeSourceInfo *Sema::SubstType(TypeLoc TL,
const MultiLevelTemplateArgumentList &Args,
SourceLocation Loc,
DeclarationName Entity) {
assert(!CodeSynthesisContexts.empty() &&
"Cannot perform an instantiation without some context on the "
"instantiation stack");
if (TL.getType().isNull())
return nullptr;
if (!TL.getType()->isInstantiationDependentType() &&
!TL.getType()->isVariablyModifiedType()) {
// FIXME: Make a copy of the TypeLoc data here, so that we can
// return a new TypeSourceInfo. Inefficient!
TypeLocBuilder TLB;
TLB.pushFullCopy(TL);
return TLB.getTypeSourceInfo(Context, TL.getType());
}
TemplateInstantiator Instantiator(*this, Args, Loc, Entity);
TypeLocBuilder TLB;
TLB.reserve(TL.getFullDataSize());
QualType Result = Instantiator.TransformType(TLB, TL);
if (Result.isNull())
return nullptr;
return TLB.getTypeSourceInfo(Context, Result);
}
/// Deprecated form of the above.
QualType Sema::SubstType(QualType T,
const MultiLevelTemplateArgumentList &TemplateArgs,
SourceLocation Loc, DeclarationName Entity) {
assert(!CodeSynthesisContexts.empty() &&
"Cannot perform an instantiation without some context on the "
"instantiation stack");
// If T is not a dependent type or a variably-modified type, there
// is nothing to do.
if (!T->isInstantiationDependentType() && !T->isVariablyModifiedType())
return T;
TemplateInstantiator Instantiator(*this, TemplateArgs, Loc, Entity);
return Instantiator.TransformType(T);
}
static bool NeedsInstantiationAsFunctionType(TypeSourceInfo *T) {
if (T->getType()->isInstantiationDependentType() ||
T->getType()->isVariablyModifiedType())
return true;
TypeLoc TL = T->getTypeLoc().IgnoreParens();
if (!TL.getAs<FunctionProtoTypeLoc>())
return false;
FunctionProtoTypeLoc FP = TL.castAs<FunctionProtoTypeLoc>();
for (ParmVarDecl *P : FP.getParams()) {
// This must be synthesized from a typedef.
if (!P) continue;
// If there are any parameters, a new TypeSourceInfo that refers to the
// instantiated parameters must be built.
return true;
}
return false;
}
/// A form of SubstType intended specifically for instantiating the
/// type of a FunctionDecl. Its purpose is solely to force the
/// instantiation of default-argument expressions and to avoid
/// instantiating an exception-specification.
TypeSourceInfo *Sema::SubstFunctionDeclType(TypeSourceInfo *T,
const MultiLevelTemplateArgumentList &Args,
SourceLocation Loc,
DeclarationName Entity,
CXXRecordDecl *ThisContext,
Qualifiers ThisTypeQuals) {
assert(!CodeSynthesisContexts.empty() &&
"Cannot perform an instantiation without some context on the "
"instantiation stack");
if (!NeedsInstantiationAsFunctionType(T))
return T;
TemplateInstantiator Instantiator(*this, Args, Loc, Entity);
TypeLocBuilder TLB;
TypeLoc TL = T->getTypeLoc();
TLB.reserve(TL.getFullDataSize());
QualType Result;
if (FunctionProtoTypeLoc Proto =
TL.IgnoreParens().getAs<FunctionProtoTypeLoc>()) {
// Instantiate the type, other than its exception specification. The
// exception specification is instantiated in InitFunctionInstantiation
// once we've built the FunctionDecl.
// FIXME: Set the exception specification to EST_Uninstantiated here,
// instead of rebuilding the function type again later.
Result = Instantiator.TransformFunctionProtoType(
TLB, Proto, ThisContext, ThisTypeQuals,
[](FunctionProtoType::ExceptionSpecInfo &ESI,
bool &Changed) { return false; });
} else {
Result = Instantiator.TransformType(TLB, TL);
}
if (Result.isNull())
return nullptr;
return TLB.getTypeSourceInfo(Context, Result);
}
bool Sema::SubstExceptionSpec(SourceLocation Loc,
FunctionProtoType::ExceptionSpecInfo &ESI,
SmallVectorImpl<QualType> &ExceptionStorage,
const MultiLevelTemplateArgumentList &Args) {
assert(ESI.Type != EST_Uninstantiated);
bool Changed = false;
TemplateInstantiator Instantiator(*this, Args, Loc, DeclarationName());
return Instantiator.TransformExceptionSpec(Loc, ESI, ExceptionStorage,
Changed);
}
void Sema::SubstExceptionSpec(FunctionDecl *New, const FunctionProtoType *Proto,
const MultiLevelTemplateArgumentList &Args) {
FunctionProtoType::ExceptionSpecInfo ESI =
Proto->getExtProtoInfo().ExceptionSpec;
SmallVector<QualType, 4> ExceptionStorage;
if (SubstExceptionSpec(New->getTypeSourceInfo()->getTypeLoc().getEndLoc(),
ESI, ExceptionStorage, Args))
// On error, recover by dropping the exception specification.
ESI.Type = EST_None;
UpdateExceptionSpec(New, ESI);
}
ParmVarDecl *Sema::SubstParmVarDecl(ParmVarDecl *OldParm,
const MultiLevelTemplateArgumentList &TemplateArgs,
int indexAdjustment,
Optional<unsigned> NumExpansions,
bool ExpectParameterPack) {
TypeSourceInfo *OldDI = OldParm->getTypeSourceInfo();
TypeSourceInfo *NewDI = nullptr;
TypeLoc OldTL = OldDI->getTypeLoc();
if (PackExpansionTypeLoc ExpansionTL = OldTL.getAs<PackExpansionTypeLoc>()) {
// We have a function parameter pack. Substitute into the pattern of the
// expansion.
NewDI = SubstType(ExpansionTL.getPatternLoc(), TemplateArgs,
OldParm->getLocation(), OldParm->getDeclName());
if (!NewDI)
return nullptr;
if (NewDI->getType()->containsUnexpandedParameterPack()) {
// We still have unexpanded parameter packs, which means that
// our function parameter is still a function parameter pack.
// Therefore, make its type a pack expansion type.
NewDI = CheckPackExpansion(NewDI, ExpansionTL.getEllipsisLoc(),
NumExpansions);
} else if (ExpectParameterPack) {
// We expected to get a parameter pack but didn't (because the type
// itself is not a pack expansion type), so complain. This can occur when
// the substitution goes through an alias template that "loses" the
// pack expansion.
Diag(OldParm->getLocation(),
diag::err_function_parameter_pack_without_parameter_packs)
<< NewDI->getType();
return nullptr;
}
} else {
NewDI = SubstType(OldDI, TemplateArgs, OldParm->getLocation(),
OldParm->getDeclName());
}
if (!NewDI)
return nullptr;
if (NewDI->getType()->isVoidType()) {
Diag(OldParm->getLocation(), diag::err_param_with_void_type);
return nullptr;
}
ParmVarDecl *NewParm = CheckParameter(Context.getTranslationUnitDecl(),
OldParm->getInnerLocStart(),
OldParm->getLocation(),
OldParm->getIdentifier(),
NewDI->getType(), NewDI,
OldParm->getStorageClass());
if (!NewParm)
return nullptr;
// Mark the (new) default argument as uninstantiated (if any).
if (OldParm->hasUninstantiatedDefaultArg()) {
Expr *Arg = OldParm->getUninstantiatedDefaultArg();
NewParm->setUninstantiatedDefaultArg(Arg);
} else if (OldParm->hasUnparsedDefaultArg()) {
NewParm->setUnparsedDefaultArg();
UnparsedDefaultArgInstantiations[OldParm].push_back(NewParm);
} else if (Expr *Arg = OldParm->getDefaultArg()) {
FunctionDecl *OwningFunc = cast<FunctionDecl>(OldParm->getDeclContext());
if (OwningFunc->isLexicallyWithinFunctionOrMethod()) {
// Instantiate default arguments for methods of local classes (DR1484)
// and non-defining declarations.
Sema::ContextRAII SavedContext(*this, OwningFunc);
LocalInstantiationScope Local(*this, true);
ExprResult NewArg = SubstExpr(Arg, TemplateArgs);
if (NewArg.isUsable()) {
// It would be nice if we still had this.
SourceLocation EqualLoc = NewArg.get()->getBeginLoc();
SetParamDefaultArgument(NewParm, NewArg.get(), EqualLoc);
}
} else {
// FIXME: if we non-lazily instantiated non-dependent default args for
// non-dependent parameter types we could remove a bunch of duplicate
// conversion warnings for such arguments.
NewParm->setUninstantiatedDefaultArg(Arg);
}
}
NewParm->setHasInheritedDefaultArg(OldParm->hasInheritedDefaultArg());
if (OldParm->isParameterPack() && !NewParm->isParameterPack()) {
// Add the new parameter to the instantiated parameter pack.
CurrentInstantiationScope->InstantiatedLocalPackArg(OldParm, NewParm);
} else {
// Introduce an Old -> New mapping
CurrentInstantiationScope->InstantiatedLocal(OldParm, NewParm);
}
// FIXME: OldParm may come from a FunctionProtoType, in which case CurContext
// can be anything, is this right ?
NewParm->setDeclContext(CurContext);
NewParm->setScopeInfo(OldParm->getFunctionScopeDepth(),
OldParm->getFunctionScopeIndex() + indexAdjustment);
InstantiateAttrs(TemplateArgs, OldParm, NewParm);
return NewParm;
}
/// Substitute the given template arguments into the given set of
/// parameters, producing the set of parameter types that would be generated
/// from such a substitution.
bool Sema::SubstParmTypes(
SourceLocation Loc, ArrayRef<ParmVarDecl *> Params,
const FunctionProtoType::ExtParameterInfo *ExtParamInfos,
const MultiLevelTemplateArgumentList &TemplateArgs,
SmallVectorImpl<QualType> &ParamTypes,
SmallVectorImpl<ParmVarDecl *> *OutParams,
ExtParameterInfoBuilder &ParamInfos) {
assert(!CodeSynthesisContexts.empty() &&
"Cannot perform an instantiation without some context on the "
"instantiation stack");
TemplateInstantiator Instantiator(*this, TemplateArgs, Loc,
DeclarationName());
return Instantiator.TransformFunctionTypeParams(
Loc, Params, nullptr, ExtParamInfos, ParamTypes, OutParams, ParamInfos);
}
/// 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;
SmallVector<CXXBaseSpecifier*, 4> InstantiatedBases;
for (const auto &Base : Pattern->bases()) {
if (!Base.getType()->isDependentType()) {
if (const CXXRecordDecl *RD = Base.getType()->getAsCXXRecordDecl()) {
if (RD->isInvalidDecl())
Instantiation->setInvalidDecl();
}
InstantiatedBases.push_back(new (Context) CXXBaseSpecifier(Base));
continue;
}
SourceLocation EllipsisLoc;
TypeSourceInfo *BaseTypeLoc;
if (Base.isPackExpansion()) {
// This is a pack expansion. See whether we should expand it now, or
// wait until later.
SmallVector<UnexpandedParameterPack, 2> Unexpanded;
collectUnexpandedParameterPacks(Base.getTypeSourceInfo()->getTypeLoc(),
Unexpanded);
bool ShouldExpand = false;
bool RetainExpansion = false;
Optional<unsigned> NumExpansions;
if (CheckParameterPacksForExpansion(Base.getEllipsisLoc(),
Base.getSourceRange(),
Unexpanded,
TemplateArgs, ShouldExpand,
RetainExpansion,
NumExpansions)) {
Invalid = true;
continue;
}
// If we should expand this pack expansion now, do so.
if (ShouldExpand) {
for (unsigned I = 0; I != *NumExpansions; ++I) {
Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(*this, I);
TypeSourceInfo *BaseTypeLoc = SubstType(Base.getTypeSourceInfo(),
TemplateArgs,
Base.getSourceRange().getBegin(),
DeclarationName());
if (!BaseTypeLoc) {
Invalid = true;
continue;
}
if (CXXBaseSpecifier *InstantiatedBase
= CheckBaseSpecifier(Instantiation,
Base.getSourceRange(),
Base.isVirtual(),
Base.getAccessSpecifierAsWritten(),
BaseTypeLoc,
SourceLocation()))
InstantiatedBases.push_back(InstantiatedBase);
else
Invalid = true;
}
continue;
}
// The resulting base specifier will (still) be a pack expansion.
EllipsisLoc = Base.getEllipsisLoc();
Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(*this, -1);
BaseTypeLoc = SubstType(Base.getTypeSourceInfo(),
TemplateArgs,
Base.getSourceRange().getBegin(),
DeclarationName());
} else {
BaseTypeLoc = SubstType(Base.getTypeSourceInfo(),
TemplateArgs,
Base.getSourceRange().getBegin(),
DeclarationName());
}
if (!BaseTypeLoc) {
Invalid = true;
continue;
}
if (CXXBaseSpecifier *InstantiatedBase
= CheckBaseSpecifier(Instantiation,
Base.getSourceRange(),
Base.isVirtual(),
Base.getAccessSpecifierAsWritten(),
BaseTypeLoc,
EllipsisLoc))
InstantiatedBases.push_back(InstantiatedBase);
else
Invalid = true;
}
if (!Invalid && AttachBaseSpecifiers(Instantiation, InstantiatedBases))
Invalid = true;
return Invalid;
}
// Defined via #include from SemaTemplateInstantiateDecl.cpp
namespace clang {
namespace sema {
Attr *instantiateTemplateAttribute(const Attr *At, ASTContext &C, Sema &S,
const MultiLevelTemplateArgumentList &TemplateArgs);
Attr *instantiateTemplateAttributeForDecl(
const Attr *At, ASTContext &C, Sema &S,
const MultiLevelTemplateArgumentList &TemplateArgs);
}
}
/// 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) {
CXXRecordDecl *PatternDef
= cast_or_null<CXXRecordDecl>(Pattern->getDefinition());
if (DiagnoseUninstantiableTemplate(PointOfInstantiation, Instantiation,
Instantiation->getInstantiatedFromMemberClass(),
Pattern, PatternDef, TSK, Complain))
return true;
llvm::TimeTraceScope TimeScope("InstantiateClass", [&]() {
std::string Name;
llvm::raw_string_ostream OS(Name);
Instantiation->getNameForDiagnostic(OS, getPrintingPolicy(),
/*Qualified=*/true);
return Name;
});
Pattern = PatternDef;
// Record the point of instantiation.
if (MemberSpecializationInfo *MSInfo
= Instantiation->getMemberSpecializationInfo()) {
MSInfo->setTemplateSpecializationKind(TSK);
MSInfo->setPointOfInstantiation(PointOfInstantiation);
} else if (ClassTemplateSpecializationDecl *Spec
= dyn_cast<ClassTemplateSpecializationDecl>(Instantiation)) {
Spec->setTemplateSpecializationKind(TSK);
Spec->setPointOfInstantiation(PointOfInstantiation);
}
InstantiatingTemplate Inst(*this, PointOfInstantiation, Instantiation);
if (Inst.isInvalid())
return true;
assert(!Inst.isAlreadyInstantiating() && "should have been caught by caller");
PrettyDeclStackTraceEntry CrashInfo(Context, Instantiation, SourceLocation(),
"instantiating class definition");
// Enter the scope of this instantiation. We don't use
// PushDeclContext because we don't have a scope.
ContextRAII SavedContext(*this, Instantiation);
EnterExpressionEvaluationContext EvalContext(
*this, Sema::ExpressionEvaluationContext::PotentiallyEvaluated);
// If this is an instantiation of a local class, merge this local
// instantiation scope with the enclosing scope. Otherwise, every
// instantiation of a class has its own local instantiation scope.
bool MergeWithParentScope = !Instantiation->isDefinedOutsideFunctionOrMethod();
LocalInstantiationScope Scope(*this, MergeWithParentScope);
// Some class state isn't processed immediately but delayed till class
// instantiation completes. We may not be ready to handle any delayed state
// already on the stack as it might correspond to a different class, so save
// it now and put it back later.
SavePendingParsedClassStateRAII SavedPendingParsedClassState(*this);
// Pull attributes from the pattern onto the instantiation.
InstantiateAttrs(TemplateArgs, Pattern, Instantiation);
// Start the definition of this instantiation.
Instantiation->startDefinition();
// The instantiation is visible here, even if it was first declared in an
// unimported module.
Instantiation->setVisibleDespiteOwningModule();
// FIXME: This loses the as-written tag kind for an explicit instantiation.
Instantiation->setTagKind(Pattern->getTagKind());
// Do substitution on the base class specifiers.
if (SubstBaseSpecifiers(Instantiation, Pattern, TemplateArgs))
Instantiation->setInvalidDecl();
TemplateDeclInstantiator Instantiator(*this, Instantiation, TemplateArgs);
SmallVector<Decl*, 4> Fields;
// Delay instantiation of late parsed attributes.
LateInstantiatedAttrVec LateAttrs;
Instantiator.enableLateAttributeInstantiation(&LateAttrs);
bool MightHaveConstexprVirtualFunctions = false;
for (auto *Member : Pattern->decls()) {
// Don't instantiate members not belonging in this semantic context.
// e.g. for:
// @code
// template <int i> class A {
// class B *g;
// };
// @endcode
// 'class B' has the template as lexical context but semantically it is
// introduced in namespace scope.
if (Member->getDeclContext() != Pattern)
continue;
// BlockDecls can appear in a default-member-initializer. They must be the
// child of a BlockExpr, so we only know how to instantiate them from there.
if (isa<BlockDecl>(Member))
continue;
if (Member->isInvalidDecl()) {
Instantiation->setInvalidDecl();
continue;
}
Decl *NewMember = Instantiator.Visit(Member);
if (NewMember) {
if (FieldDecl *Field = dyn_cast<FieldDecl>(NewMember)) {
Fields.push_back(Field);
} else if (EnumDecl *Enum = dyn_cast<EnumDecl>(NewMember)) {
// C++11 [temp.inst]p1: The implicit instantiation of a class template
// specialization causes the implicit instantiation of the definitions
// of unscoped member enumerations.
// Record a point of instantiation for this implicit instantiation.
if (TSK == TSK_ImplicitInstantiation && !Enum->isScoped() &&
Enum->isCompleteDefinition()) {
MemberSpecializationInfo *MSInfo =Enum->getMemberSpecializationInfo();
assert(MSInfo && "no spec info for member enum specialization");
MSInfo->setTemplateSpecializationKind(TSK_ImplicitInstantiation);
MSInfo->setPointOfInstantiation(PointOfInstantiation);
}
} else if (StaticAssertDecl *SA = dyn_cast<StaticAssertDecl>(NewMember)) {
if (SA->isFailed()) {
// A static_assert failed. Bail out; instantiating this
// class is probably not meaningful.
Instantiation->setInvalidDecl();
break;
}
} else if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewMember)) {
if (MD->isConstexpr() && !MD->getFriendObjectKind() &&
(MD->isVirtualAsWritten() || Instantiation->getNumBases()))
MightHaveConstexprVirtualFunctions = true;
}
if (NewMember->isInvalidDecl())
Instantiation->setInvalidDecl();
} else {
// FIXME: Eventually, a NULL return will mean that one of the
// instantiations was a semantic disaster, and we'll want to mark the
// declaration invalid.
// For now, we expect to skip some members that we can't yet handle.
}
}
// Finish checking fields.
ActOnFields(nullptr, Instantiation->getLocation(), Instantiation, Fields,
SourceLocation(), SourceLocation(), ParsedAttributesView());
CheckCompletedCXXClass(Instantiation);
// Default arguments are parsed, if not instantiated. We can go instantiate
// default arg exprs for default constructors if necessary now.
ActOnFinishCXXNonNestedClass(Instantiation);
// Instantiate late parsed attributes, and attach them to their decls.
// See Sema::InstantiateAttrs
for (LateInstantiatedAttrVec::iterator I = LateAttrs.begin(),
E = LateAttrs.end(); I != E; ++I) {
assert(CurrentInstantiationScope == Instantiator.getStartingScope());
CurrentInstantiationScope = I->Scope;
// Allow 'this' within late-parsed attributes.
NamedDecl *ND = dyn_cast<NamedDecl>(I->NewDecl);
CXXRecordDecl *ThisContext =
dyn_cast_or_null<CXXRecordDecl>(ND->getDeclContext());
CXXThisScopeRAII ThisScope(*this, ThisContext, Qualifiers(),
ND && ND->isCXXInstanceMember());
Attr *NewAttr =
instantiateTemplateAttribute(I->TmplAttr, Context, *this, TemplateArgs);
I->NewDecl->addAttr(NewAttr);
LocalInstantiationScope::deleteScopes(I->Scope,
Instantiator.getStartingScope());
}
Instantiator.disableLateAttributeInstantiation();
LateAttrs.clear();
ActOnFinishDelayedMemberInitializers(Instantiation);
// FIXME: We should do something similar for explicit instantiations so they
// end up in the right module.
if (TSK == TSK_ImplicitInstantiation) {
Instantiation->setLocation(Pattern->getLocation());
Instantiation->setLocStart(Pattern->getInnerLocStart());
Instantiation->setBraceRange(Pattern->getBraceRange());
}
if (!Instantiation->isInvalidDecl()) {
// Perform any dependent diagnostics from the pattern.
PerformDependentDiagnostics(Pattern, TemplateArgs);
// Instantiate any out-of-line class template partial
// specializations now.
for (TemplateDeclInstantiator::delayed_partial_spec_iterator
P = Instantiator.delayed_partial_spec_begin(),
PEnd = Instantiator.delayed_partial_spec_end();
P != PEnd; ++P) {
if (!Instantiator.InstantiateClassTemplatePartialSpecialization(
P->first, P->second)) {
Instantiation->setInvalidDecl();
break;
}
}
// Instantiate any out-of-line variable template partial
// specializations now.
for (TemplateDeclInstantiator::delayed_var_partial_spec_iterator
P = Instantiator.delayed_var_partial_spec_begin(),
PEnd = Instantiator.delayed_var_partial_spec_end();
P != PEnd; ++P) {
if (!Instantiator.InstantiateVarTemplatePartialSpecialization(
P->first, P->second)) {
Instantiation->setInvalidDecl();
break;
}
}
}
// Exit the scope of this instantiation.
SavedContext.pop();
if (!Instantiation->isInvalidDecl()) {
Consumer.HandleTagDeclDefinition(Instantiation);
// Always emit the vtable for an explicit instantiation definition
// of a polymorphic class template specialization. Otherwise, eagerly
// instantiate only constexpr virtual functions in preparation for their use
// in constant evaluation.
if (TSK == TSK_ExplicitInstantiationDefinition)
MarkVTableUsed(PointOfInstantiation, Instantiation, true);
else if (MightHaveConstexprVirtualFunctions)
MarkVirtualMembersReferenced(PointOfInstantiation, Instantiation,
/*ConstexprOnly*/ true);
}
return Instantiation->isInvalidDecl();
}
/// Instantiate the definition of an enum 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 a member enumeration of a class
/// temploid specialization, or a local enumeration within a
/// function temploid specialization.
/// \param Pattern The templated declaration from which the instantiation
/// occurs.
/// \param TemplateArgs The template arguments to be substituted into
/// the pattern.
/// \param TSK The kind of implicit or explicit instantiation to perform.
///
/// \return \c true if an error occurred, \c false otherwise.
bool Sema::InstantiateEnum(SourceLocation PointOfInstantiation,
EnumDecl *Instantiation, EnumDecl *Pattern,
const MultiLevelTemplateArgumentList &TemplateArgs,
TemplateSpecializationKind TSK) {
EnumDecl *PatternDef = Pattern->getDefinition();
if (DiagnoseUninstantiableTemplate(PointOfInstantiation, Instantiation,
Instantiation->getInstantiatedFromMemberEnum(),
Pattern, PatternDef, TSK,/*Complain*/true))
return true;
Pattern = PatternDef;
// Record the point of instantiation.
if (MemberSpecializationInfo *MSInfo
= Instantiation->getMemberSpecializationInfo()) {
MSInfo->setTemplateSpecializationKind(TSK);
MSInfo->setPointOfInstantiation(PointOfInstantiation);
}
InstantiatingTemplate Inst(*this, PointOfInstantiation, Instantiation);
if (Inst.isInvalid())
return true;
if (Inst.isAlreadyInstantiating())
return false;
PrettyDeclStackTraceEntry CrashInfo(Context, Instantiation, SourceLocation(),
"instantiating enum definition");
// The instantiation is visible here, even if it was first declared in an
// unimported module.
Instantiation->setVisibleDespiteOwningModule();
// Enter the scope of this instantiation. We don't use
// PushDeclContext because we don't have a scope.
ContextRAII SavedContext(*this, Instantiation);
EnterExpressionEvaluationContext EvalContext(
*this, Sema::ExpressionEvaluationContext::PotentiallyEvaluated);
LocalInstantiationScope Scope(*this, /*MergeWithParentScope*/true);
// Pull attributes from the pattern onto the instantiation.
InstantiateAttrs(TemplateArgs, Pattern, Instantiation);
TemplateDeclInstantiator Instantiator(*this, Instantiation, TemplateArgs);
Instantiator.InstantiateEnumDefinition(Instantiation, Pattern);
// Exit the scope of this instantiation.
SavedContext.pop();
return Instantiation->isInvalidDecl();
}
/// Instantiate the definition of a field from the 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 a class of a class temploid
/// specialization, or a local enumeration within a function temploid
/// specialization.
/// \param Pattern The templated declaration from which the instantiation
/// occurs.
/// \param TemplateArgs The template arguments to be substituted into
/// the pattern.
///
/// \return \c true if an error occurred, \c false otherwise.
bool Sema::InstantiateInClassInitializer(
SourceLocation PointOfInstantiation, FieldDecl *Instantiation,
FieldDecl *Pattern, const MultiLevelTemplateArgumentList &TemplateArgs) {
// If there is no initializer, we don't need to do anything.
if (!Pattern->hasInClassInitializer())
return false;
assert(Instantiation->getInClassInitStyle() ==
Pattern->getInClassInitStyle() &&
"pattern and instantiation disagree about init style");
// Error out if we haven't parsed the initializer of the pattern yet because
// we are waiting for the closing brace of the outer class.
Expr *OldInit = Pattern->getInClassInitializer();
if (!OldInit) {
RecordDecl *PatternRD = Pattern->getParent();
RecordDecl *OutermostClass = PatternRD->getOuterLexicalRecordContext();
Diag(PointOfInstantiation,
diag::err_in_class_initializer_not_yet_parsed)
<< OutermostClass << Pattern;
Diag(Pattern->getEndLoc(), diag::note_in_class_initializer_not_yet_parsed);
Instantiation->setInvalidDecl();
return true;
}
InstantiatingTemplate Inst(*this, PointOfInstantiation, Instantiation);
if (Inst.isInvalid())
return true;
if (Inst.isAlreadyInstantiating()) {
// Error out if we hit an instantiation cycle for this initializer.
Diag(PointOfInstantiation, diag::err_in_class_initializer_cycle)
<< Instantiation;
return true;
}
PrettyDeclStackTraceEntry CrashInfo(Context, Instantiation, SourceLocation(),
"instantiating default member init");
// Enter the scope of this instantiation. We don't use PushDeclContext because
// we don't have a scope.
ContextRAII SavedContext(*this, Instantiation->getParent());
EnterExpressionEvaluationContext EvalContext(
*this, Sema::ExpressionEvaluationContext::PotentiallyEvaluated);
LocalInstantiationScope Scope(*this, true);
// Instantiate the initializer.
ActOnStartCXXInClassMemberInitializer();
CXXThisScopeRAII ThisScope(*this, Instantiation->getParent(), Qualifiers());
ExprResult NewInit = SubstInitializer(OldInit, TemplateArgs,
/*CXXDirectInit=*/false);
Expr *Init = NewInit.get();
assert((!Init || !isa<ParenListExpr>(Init)) && "call-style init in class");
ActOnFinishCXXInClassMemberInitializer(
Instantiation, Init ? Init->getBeginLoc() : SourceLocation(), Init);
if (auto *L = getASTMutationListener())
L->DefaultMemberInitializerInstantiated(Instantiation);
// Return true if the in-class initializer is still missing.
return !Instantiation->getInClassInitializer();
}
namespace {
/// A partial specialization whose template arguments have matched
/// a given template-id.
struct PartialSpecMatchResult {
ClassTemplatePartialSpecializationDecl *Partial;
TemplateArgumentList *Args;
};
}
bool Sema::usesPartialOrExplicitSpecialization(
SourceLocation Loc, ClassTemplateSpecializationDecl *ClassTemplateSpec) {
if (ClassTemplateSpec->getTemplateSpecializationKind() ==
TSK_ExplicitSpecialization)
return true;
SmallVector<ClassTemplatePartialSpecializationDecl *, 4> PartialSpecs;
ClassTemplateSpec->getSpecializedTemplate()
->getPartialSpecializations(PartialSpecs);
for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I) {
TemplateDeductionInfo Info(Loc);
if (!DeduceTemplateArguments(PartialSpecs[I],
ClassTemplateSpec->getTemplateArgs(), Info))
return true;
}
return false;
}
/// Get the instantiation pattern to use to instantiate the definition of a
/// given ClassTemplateSpecializationDecl (either the pattern of the primary
/// template or of a partial specialization).
static CXXRecordDecl *
getPatternForClassTemplateSpecialization(
Sema &S, SourceLocation PointOfInstantiation,
ClassTemplateSpecializationDecl *ClassTemplateSpec,
TemplateSpecializationKind TSK, bool Complain) {
Sema::InstantiatingTemplate Inst(S, PointOfInstantiation, ClassTemplateSpec);
if (Inst.isInvalid() || Inst.isAlreadyInstantiating())
return nullptr;
llvm::PointerUnion<ClassTemplateDecl *,
ClassTemplatePartialSpecializationDecl *>
Specialized = ClassTemplateSpec->getSpecializedTemplateOrPartial();
if (!Specialized.is<ClassTemplatePartialSpecializationDecl *>()) {
// Find best matching specialization.
ClassTemplateDecl *Template = ClassTemplateSpec->getSpecializedTemplate();
// 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 PartialSpecMatchResult MatchResult;
SmallVector<MatchResult, 4> Matched;
SmallVector<ClassTemplatePartialSpecializationDecl *, 4> PartialSpecs;
Template->getPartialSpecializations(PartialSpecs);
TemplateSpecCandidateSet FailedCandidates(PointOfInstantiation);
for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I) {
ClassTemplatePartialSpecializationDecl *Partial = PartialSpecs[I];
TemplateDeductionInfo Info(FailedCandidates.getLocation());
if (Sema::TemplateDeductionResult Result = S.DeduceTemplateArguments(
Partial, ClassTemplateSpec->getTemplateArgs(), Info)) {
// Store the failed-deduction information for use in diagnostics, later.
// TODO: Actually use the failed-deduction info?
FailedCandidates.addCandidate().set(
DeclAccessPair::make(Template, AS_public), Partial,
MakeDeductionFailureInfo(S.Context, Result, Info));
(void)Result;
} else {
Matched.push_back(PartialSpecMatchResult());
Matched.back().Partial = Partial;
Matched.back().Args = Info.take();
}
}
// If we're dealing with a member template where the template parameters
// have been instantiated, this provides the original template parameters
// from which the member template's parameters were instantiated.
if (Matched.size() >= 1) {
SmallVectorImpl<MatchResult>::iterator Best = Matched.begin();
if (Matched.size() == 1) {
// -- If exactly one matching specialization is found, the
// instantiation is generated from that specialization.
// We don't need to do anything for this.
} else {
// -- 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.
for (SmallVectorImpl<MatchResult>::iterator P = Best + 1,
PEnd = Matched.end();
P != PEnd; ++P) {
if (S.getMoreSpecializedPartialSpecialization(
P->Partial, Best->Partial, PointOfInstantiation) ==
P->Partial)
Best = P;
}
// Determine if the best partial specialization is more specialized than
// the others.
bool Ambiguous = false;
for (SmallVectorImpl<MatchResult>::iterator P = Matched.begin(),
PEnd = Matched.end();
P != PEnd; ++P) {
if (P != Best && S.getMoreSpecializedPartialSpecialization(
P->Partial, Best->Partial,
PointOfInstantiation) != Best->Partial) {
Ambiguous = true;
break;
}
}
if (Ambiguous) {
// Partial ordering did not produce a clear winner. Complain.
Inst.Clear();
ClassTemplateSpec->setInvalidDecl();
S.Diag(PointOfInstantiation,
diag::err_partial_spec_ordering_ambiguous)
<< ClassTemplateSpec;
// Print the matching partial specializations.
for (SmallVectorImpl<MatchResult>::iterator P = Matched.begin(),
PEnd = Matched.end();
P != PEnd; ++P)
S.Diag(P->Partial->getLocation(), diag::note_partial_spec_match)
<< S.getTemplateArgumentBindingsText(
P->Partial->getTemplateParameters(), *P->Args);
return nullptr;
}
}
ClassTemplateSpec->setInstantiationOf(Best->Partial, Best->Args);
} else {
// -- If no matches are found, the instantiation is generated
// from the primary template.
}
}
CXXRecordDecl *Pattern = nullptr;
Specialized = ClassTemplateSpec->getSpecializedTemplateOrPartial();
if (auto *PartialSpec =
Specialized.dyn_cast<ClassTemplatePartialSpecializationDecl *>()) {
// Instantiate using the best class template partial specialization.