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//===--- SemaTemplateInstantiateDecl.cpp - C++ Template Decl 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 for declarations.
//
//===----------------------------------------------------------------------===/
#include "clang/Sema/SemaInternal.h"
#include "clang/AST/ASTConsumer.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/ASTMutationListener.h"
#include "clang/AST/DeclTemplate.h"
#include "clang/AST/DeclVisitor.h"
#include "clang/AST/DependentDiagnostic.h"
#include "clang/AST/Expr.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/PrettyDeclStackTrace.h"
#include "clang/AST/TypeLoc.h"
#include "clang/Sema/Initialization.h"
#include "clang/Sema/Lookup.h"
#include "clang/Sema/Template.h"
#include "clang/Sema/TemplateInstCallback.h"
#include "llvm/Support/TimeProfiler.h"
using namespace clang;
static bool isDeclWithinFunction(const Decl *D) {
const DeclContext *DC = D->getDeclContext();
if (DC->isFunctionOrMethod())
return true;
if (DC->isRecord())
return cast<CXXRecordDecl>(DC)->isLocalClass();
return false;
}
template<typename DeclT>
static bool SubstQualifier(Sema &SemaRef, const DeclT *OldDecl, DeclT *NewDecl,
const MultiLevelTemplateArgumentList &TemplateArgs) {
if (!OldDecl->getQualifierLoc())
return false;
assert((NewDecl->getFriendObjectKind() ||
!OldDecl->getLexicalDeclContext()->isDependentContext()) &&
"non-friend with qualified name defined in dependent context");
Sema::ContextRAII SavedContext(
SemaRef,
const_cast<DeclContext *>(NewDecl->getFriendObjectKind()
? NewDecl->getLexicalDeclContext()
: OldDecl->getLexicalDeclContext()));
NestedNameSpecifierLoc NewQualifierLoc
= SemaRef.SubstNestedNameSpecifierLoc(OldDecl->getQualifierLoc(),
TemplateArgs);
if (!NewQualifierLoc)
return true;
NewDecl->setQualifierInfo(NewQualifierLoc);
return false;
}
bool TemplateDeclInstantiator::SubstQualifier(const DeclaratorDecl *OldDecl,
DeclaratorDecl *NewDecl) {
return ::SubstQualifier(SemaRef, OldDecl, NewDecl, TemplateArgs);
}
bool TemplateDeclInstantiator::SubstQualifier(const TagDecl *OldDecl,
TagDecl *NewDecl) {
return ::SubstQualifier(SemaRef, OldDecl, NewDecl, TemplateArgs);
}
// Include attribute instantiation code.
#include "clang/Sema/AttrTemplateInstantiate.inc"
static void instantiateDependentAlignedAttr(
Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
const AlignedAttr *Aligned, Decl *New, bool IsPackExpansion) {
if (Aligned->isAlignmentExpr()) {
// The alignment expression is a constant expression.
EnterExpressionEvaluationContext Unevaluated(
S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
ExprResult Result = S.SubstExpr(Aligned->getAlignmentExpr(), TemplateArgs);
if (!Result.isInvalid())
S.AddAlignedAttr(New, *Aligned, Result.getAs<Expr>(), IsPackExpansion);
} else {
TypeSourceInfo *Result = S.SubstType(Aligned->getAlignmentType(),
TemplateArgs, Aligned->getLocation(),
DeclarationName());
if (Result)
S.AddAlignedAttr(New, *Aligned, Result, IsPackExpansion);
}
}
static void instantiateDependentAlignedAttr(
Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
const AlignedAttr *Aligned, Decl *New) {
if (!Aligned->isPackExpansion()) {
instantiateDependentAlignedAttr(S, TemplateArgs, Aligned, New, false);
return;
}
SmallVector<UnexpandedParameterPack, 2> Unexpanded;
if (Aligned->isAlignmentExpr())
S.collectUnexpandedParameterPacks(Aligned->getAlignmentExpr(),
Unexpanded);
else
S.collectUnexpandedParameterPacks(Aligned->getAlignmentType()->getTypeLoc(),
Unexpanded);
assert(!Unexpanded.empty() && "Pack expansion without parameter packs?");
// Determine whether we can expand this attribute pack yet.
bool Expand = true, RetainExpansion = false;
Optional<unsigned> NumExpansions;
// FIXME: Use the actual location of the ellipsis.
SourceLocation EllipsisLoc = Aligned->getLocation();
if (S.CheckParameterPacksForExpansion(EllipsisLoc, Aligned->getRange(),
Unexpanded, TemplateArgs, Expand,
RetainExpansion, NumExpansions))
return;
if (!Expand) {
Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(S, -1);
instantiateDependentAlignedAttr(S, TemplateArgs, Aligned, New, true);
} else {
for (unsigned I = 0; I != *NumExpansions; ++I) {
Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(S, I);
instantiateDependentAlignedAttr(S, TemplateArgs, Aligned, New, false);
}
}
}
static void instantiateDependentAssumeAlignedAttr(
Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
const AssumeAlignedAttr *Aligned, Decl *New) {
// The alignment expression is a constant expression.
EnterExpressionEvaluationContext Unevaluated(
S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
Expr *E, *OE = nullptr;
ExprResult Result = S.SubstExpr(Aligned->getAlignment(), TemplateArgs);
if (Result.isInvalid())
return;
E = Result.getAs<Expr>();
if (Aligned->getOffset()) {
Result = S.SubstExpr(Aligned->getOffset(), TemplateArgs);
if (Result.isInvalid())
return;
OE = Result.getAs<Expr>();
}
S.AddAssumeAlignedAttr(New, *Aligned, E, OE);
}
static void instantiateDependentAlignValueAttr(
Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
const AlignValueAttr *Aligned, Decl *New) {
// The alignment expression is a constant expression.
EnterExpressionEvaluationContext Unevaluated(
S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
ExprResult Result = S.SubstExpr(Aligned->getAlignment(), TemplateArgs);
if (!Result.isInvalid())
S.AddAlignValueAttr(New, *Aligned, Result.getAs<Expr>());
}
static void instantiateDependentAllocAlignAttr(
Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
const AllocAlignAttr *Align, Decl *New) {
Expr *Param = IntegerLiteral::Create(
S.getASTContext(),
llvm::APInt(64, Align->getParamIndex().getSourceIndex()),
S.getASTContext().UnsignedLongLongTy, Align->getLocation());
S.AddAllocAlignAttr(New, *Align, Param);
}
static Expr *instantiateDependentFunctionAttrCondition(
Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
const Attr *A, Expr *OldCond, const Decl *Tmpl, FunctionDecl *New) {
Expr *Cond = nullptr;
{
Sema::ContextRAII SwitchContext(S, New);
EnterExpressionEvaluationContext Unevaluated(
S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
ExprResult Result = S.SubstExpr(OldCond, TemplateArgs);
if (Result.isInvalid())
return nullptr;
Cond = Result.getAs<Expr>();
}
if (!Cond->isTypeDependent()) {
ExprResult Converted = S.PerformContextuallyConvertToBool(Cond);
if (Converted.isInvalid())
return nullptr;
Cond = Converted.get();
}
SmallVector<PartialDiagnosticAt, 8> Diags;
if (OldCond->isValueDependent() && !Cond->isValueDependent() &&
!Expr::isPotentialConstantExprUnevaluated(Cond, New, Diags)) {
S.Diag(A->getLocation(), diag::err_attr_cond_never_constant_expr) << A;
for (const auto &P : Diags)
S.Diag(P.first, P.second);
return nullptr;
}
return Cond;
}
static void instantiateDependentEnableIfAttr(
Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
const EnableIfAttr *EIA, const Decl *Tmpl, FunctionDecl *New) {
Expr *Cond = instantiateDependentFunctionAttrCondition(
S, TemplateArgs, EIA, EIA->getCond(), Tmpl, New);
if (Cond)
New->addAttr(new (S.getASTContext()) EnableIfAttr(S.getASTContext(), *EIA,
Cond, EIA->getMessage()));
}
static void instantiateDependentDiagnoseIfAttr(
Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
const DiagnoseIfAttr *DIA, const Decl *Tmpl, FunctionDecl *New) {
Expr *Cond = instantiateDependentFunctionAttrCondition(
S, TemplateArgs, DIA, DIA->getCond(), Tmpl, New);
if (Cond)
New->addAttr(new (S.getASTContext()) DiagnoseIfAttr(
S.getASTContext(), *DIA, Cond, DIA->getMessage(),
DIA->getDiagnosticType(), DIA->getArgDependent(), New));
}
// Constructs and adds to New a new instance of CUDALaunchBoundsAttr using
// template A as the base and arguments from TemplateArgs.
static void instantiateDependentCUDALaunchBoundsAttr(
Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
const CUDALaunchBoundsAttr &Attr, Decl *New) {
// The alignment expression is a constant expression.
EnterExpressionEvaluationContext Unevaluated(
S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
ExprResult Result = S.SubstExpr(Attr.getMaxThreads(), TemplateArgs);
if (Result.isInvalid())
return;
Expr *MaxThreads = Result.getAs<Expr>();
Expr *MinBlocks = nullptr;
if (Attr.getMinBlocks()) {
Result = S.SubstExpr(Attr.getMinBlocks(), TemplateArgs);
if (Result.isInvalid())
return;
MinBlocks = Result.getAs<Expr>();
}
S.AddLaunchBoundsAttr(New, Attr, MaxThreads, MinBlocks);
}
static void
instantiateDependentModeAttr(Sema &S,
const MultiLevelTemplateArgumentList &TemplateArgs,
const ModeAttr &Attr, Decl *New) {
S.AddModeAttr(New, Attr, Attr.getMode(),
/*InInstantiation=*/true);
}
/// Instantiation of 'declare simd' attribute and its arguments.
static void instantiateOMPDeclareSimdDeclAttr(
Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
const OMPDeclareSimdDeclAttr &Attr, Decl *New) {
// Allow 'this' in clauses with varlists.
if (auto *FTD = dyn_cast<FunctionTemplateDecl>(New))
New = FTD->getTemplatedDecl();
auto *FD = cast<FunctionDecl>(New);
auto *ThisContext = dyn_cast_or_null<CXXRecordDecl>(FD->getDeclContext());
SmallVector<Expr *, 4> Uniforms, Aligneds, Alignments, Linears, Steps;
SmallVector<unsigned, 4> LinModifiers;
auto SubstExpr = [&](Expr *E) -> ExprResult {
if (auto *DRE = dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts()))
if (auto *PVD = dyn_cast<ParmVarDecl>(DRE->getDecl())) {
Sema::ContextRAII SavedContext(S, FD);
LocalInstantiationScope Local(S);
if (FD->getNumParams() > PVD->getFunctionScopeIndex())
Local.InstantiatedLocal(
PVD, FD->getParamDecl(PVD->getFunctionScopeIndex()));
return S.SubstExpr(E, TemplateArgs);
}
Sema::CXXThisScopeRAII ThisScope(S, ThisContext, Qualifiers(),
FD->isCXXInstanceMember());
return S.SubstExpr(E, TemplateArgs);
};
// Substitute a single OpenMP clause, which is a potentially-evaluated
// full-expression.
auto Subst = [&](Expr *E) -> ExprResult {
EnterExpressionEvaluationContext Evaluated(
S, Sema::ExpressionEvaluationContext::PotentiallyEvaluated);
ExprResult Res = SubstExpr(E);
if (Res.isInvalid())
return Res;
return S.ActOnFinishFullExpr(Res.get(), false);
};
ExprResult Simdlen;
if (auto *E = Attr.getSimdlen())
Simdlen = Subst(E);
if (Attr.uniforms_size() > 0) {
for(auto *E : Attr.uniforms()) {
ExprResult Inst = Subst(E);
if (Inst.isInvalid())
continue;
Uniforms.push_back(Inst.get());
}
}
auto AI = Attr.alignments_begin();
for (auto *E : Attr.aligneds()) {
ExprResult Inst = Subst(E);
if (Inst.isInvalid())
continue;
Aligneds.push_back(Inst.get());
Inst = ExprEmpty();
if (*AI)
Inst = S.SubstExpr(*AI, TemplateArgs);
Alignments.push_back(Inst.get());
++AI;
}
auto SI = Attr.steps_begin();
for (auto *E : Attr.linears()) {
ExprResult Inst = Subst(E);
if (Inst.isInvalid())
continue;
Linears.push_back(Inst.get());
Inst = ExprEmpty();
if (*SI)
Inst = S.SubstExpr(*SI, TemplateArgs);
Steps.push_back(Inst.get());
++SI;
}
LinModifiers.append(Attr.modifiers_begin(), Attr.modifiers_end());
(void)S.ActOnOpenMPDeclareSimdDirective(
S.ConvertDeclToDeclGroup(New), Attr.getBranchState(), Simdlen.get(),
Uniforms, Aligneds, Alignments, Linears, LinModifiers, Steps,
Attr.getRange());
}
/// Instantiation of 'declare variant' attribute and its arguments.
static void instantiateOMPDeclareVariantAttr(
Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
const OMPDeclareVariantAttr &Attr, Decl *New) {
// Allow 'this' in clauses with varlists.
if (auto *FTD = dyn_cast<FunctionTemplateDecl>(New))
New = FTD->getTemplatedDecl();
auto *FD = cast<FunctionDecl>(New);
auto *ThisContext = dyn_cast_or_null<CXXRecordDecl>(FD->getDeclContext());
auto &&SubstExpr = [FD, ThisContext, &S, &TemplateArgs](Expr *E) {
if (auto *DRE = dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts()))
if (auto *PVD = dyn_cast<ParmVarDecl>(DRE->getDecl())) {
Sema::ContextRAII SavedContext(S, FD);
LocalInstantiationScope Local(S);
if (FD->getNumParams() > PVD->getFunctionScopeIndex())
Local.InstantiatedLocal(
PVD, FD->getParamDecl(PVD->getFunctionScopeIndex()));
return S.SubstExpr(E, TemplateArgs);
}
Sema::CXXThisScopeRAII ThisScope(S, ThisContext, Qualifiers(),
FD->isCXXInstanceMember());
return S.SubstExpr(E, TemplateArgs);
};
// Substitute a single OpenMP clause, which is a potentially-evaluated
// full-expression.
auto &&Subst = [&SubstExpr, &S](Expr *E) {
EnterExpressionEvaluationContext Evaluated(
S, Sema::ExpressionEvaluationContext::PotentiallyEvaluated);
ExprResult Res = SubstExpr(E);
if (Res.isInvalid())
return Res;
return S.ActOnFinishFullExpr(Res.get(), false);
};
ExprResult VariantFuncRef;
if (Expr *E = Attr.getVariantFuncRef())
VariantFuncRef = Subst(E);
ExprResult Score;
if (Expr *E = Attr.getScore())
Score = Subst(E);
// Check function/variant ref.
Optional<std::pair<FunctionDecl *, Expr *>> DeclVarData =
S.checkOpenMPDeclareVariantFunction(
S.ConvertDeclToDeclGroup(New), VariantFuncRef.get(), Attr.getRange());
if (!DeclVarData)
return;
// Instantiate the attribute.
Sema::OpenMPDeclareVariantCtsSelectorData Data(
Attr.getCtxSelectorSet(), Attr.getCtxSelector(),
llvm::makeMutableArrayRef(Attr.implVendors_begin(),
Attr.implVendors_size()),
Score);
S.ActOnOpenMPDeclareVariantDirective(DeclVarData.getValue().first,
DeclVarData.getValue().second,
Attr.getRange(), Data);
}
static void instantiateDependentAMDGPUFlatWorkGroupSizeAttr(
Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
const AMDGPUFlatWorkGroupSizeAttr &Attr, Decl *New) {
// Both min and max expression are constant expressions.
EnterExpressionEvaluationContext Unevaluated(
S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
ExprResult Result = S.SubstExpr(Attr.getMin(), TemplateArgs);
if (Result.isInvalid())
return;
Expr *MinExpr = Result.getAs<Expr>();
Result = S.SubstExpr(Attr.getMax(), TemplateArgs);
if (Result.isInvalid())
return;
Expr *MaxExpr = Result.getAs<Expr>();
S.addAMDGPUFlatWorkGroupSizeAttr(New, Attr, MinExpr, MaxExpr);
}
static ExplicitSpecifier
instantiateExplicitSpecifier(Sema &S,
const MultiLevelTemplateArgumentList &TemplateArgs,
ExplicitSpecifier ES, FunctionDecl *New) {
if (!ES.getExpr())
return ES;
Expr *OldCond = ES.getExpr();
Expr *Cond = nullptr;
{
EnterExpressionEvaluationContext Unevaluated(
S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
ExprResult SubstResult = S.SubstExpr(OldCond, TemplateArgs);
if (SubstResult.isInvalid()) {
return ExplicitSpecifier::Invalid();
}
Cond = SubstResult.get();
}
ExplicitSpecifier Result(Cond, ES.getKind());
if (!Cond->isTypeDependent())
S.tryResolveExplicitSpecifier(Result);
return Result;
}
static void instantiateDependentAMDGPUWavesPerEUAttr(
Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
const AMDGPUWavesPerEUAttr &Attr, Decl *New) {
// Both min and max expression are constant expressions.
EnterExpressionEvaluationContext Unevaluated(
S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
ExprResult Result = S.SubstExpr(Attr.getMin(), TemplateArgs);
if (Result.isInvalid())
return;
Expr *MinExpr = Result.getAs<Expr>();
Expr *MaxExpr = nullptr;
if (auto Max = Attr.getMax()) {
Result = S.SubstExpr(Max, TemplateArgs);
if (Result.isInvalid())
return;
MaxExpr = Result.getAs<Expr>();
}
S.addAMDGPUWavesPerEUAttr(New, Attr, MinExpr, MaxExpr);
}
void Sema::InstantiateAttrsForDecl(
const MultiLevelTemplateArgumentList &TemplateArgs, const Decl *Tmpl,
Decl *New, LateInstantiatedAttrVec *LateAttrs,
LocalInstantiationScope *OuterMostScope) {
if (NamedDecl *ND = dyn_cast<NamedDecl>(New)) {
for (const auto *TmplAttr : Tmpl->attrs()) {
// FIXME: If any of the special case versions from InstantiateAttrs become
// applicable to template declaration, we'll need to add them here.
CXXThisScopeRAII ThisScope(
*this, dyn_cast_or_null<CXXRecordDecl>(ND->getDeclContext()),
Qualifiers(), ND->isCXXInstanceMember());
Attr *NewAttr = sema::instantiateTemplateAttributeForDecl(
TmplAttr, Context, *this, TemplateArgs);
if (NewAttr)
New->addAttr(NewAttr);
}
}
}
static Sema::RetainOwnershipKind
attrToRetainOwnershipKind(const Attr *A) {
switch (A->getKind()) {
case clang::attr::CFConsumed:
return Sema::RetainOwnershipKind::CF;
case clang::attr::OSConsumed:
return Sema::RetainOwnershipKind::OS;
case clang::attr::NSConsumed:
return Sema::RetainOwnershipKind::NS;
default:
llvm_unreachable("Wrong argument supplied");
}
}
void Sema::InstantiateAttrs(const MultiLevelTemplateArgumentList &TemplateArgs,
const Decl *Tmpl, Decl *New,
LateInstantiatedAttrVec *LateAttrs,
LocalInstantiationScope *OuterMostScope) {
for (const auto *TmplAttr : Tmpl->attrs()) {
// FIXME: This should be generalized to more than just the AlignedAttr.
const AlignedAttr *Aligned = dyn_cast<AlignedAttr>(TmplAttr);
if (Aligned && Aligned->isAlignmentDependent()) {
instantiateDependentAlignedAttr(*this, TemplateArgs, Aligned, New);
continue;
}
if (const auto *AssumeAligned = dyn_cast<AssumeAlignedAttr>(TmplAttr)) {
instantiateDependentAssumeAlignedAttr(*this, TemplateArgs, AssumeAligned, New);
continue;
}
if (const auto *AlignValue = dyn_cast<AlignValueAttr>(TmplAttr)) {
instantiateDependentAlignValueAttr(*this, TemplateArgs, AlignValue, New);
continue;
}
if (const auto *AllocAlign = dyn_cast<AllocAlignAttr>(TmplAttr)) {
instantiateDependentAllocAlignAttr(*this, TemplateArgs, AllocAlign, New);
continue;
}
if (const auto *EnableIf = dyn_cast<EnableIfAttr>(TmplAttr)) {
instantiateDependentEnableIfAttr(*this, TemplateArgs, EnableIf, Tmpl,
cast<FunctionDecl>(New));
continue;
}
if (const auto *DiagnoseIf = dyn_cast<DiagnoseIfAttr>(TmplAttr)) {
instantiateDependentDiagnoseIfAttr(*this, TemplateArgs, DiagnoseIf, Tmpl,
cast<FunctionDecl>(New));
continue;
}
if (const auto *CUDALaunchBounds =
dyn_cast<CUDALaunchBoundsAttr>(TmplAttr)) {
instantiateDependentCUDALaunchBoundsAttr(*this, TemplateArgs,
*CUDALaunchBounds, New);
continue;
}
if (const auto *Mode = dyn_cast<ModeAttr>(TmplAttr)) {
instantiateDependentModeAttr(*this, TemplateArgs, *Mode, New);
continue;
}
if (const auto *OMPAttr = dyn_cast<OMPDeclareSimdDeclAttr>(TmplAttr)) {
instantiateOMPDeclareSimdDeclAttr(*this, TemplateArgs, *OMPAttr, New);
continue;
}
if (const auto *OMPAttr = dyn_cast<OMPDeclareVariantAttr>(TmplAttr)) {
instantiateOMPDeclareVariantAttr(*this, TemplateArgs, *OMPAttr, New);
continue;
}
if (const auto *AMDGPUFlatWorkGroupSize =
dyn_cast<AMDGPUFlatWorkGroupSizeAttr>(TmplAttr)) {
instantiateDependentAMDGPUFlatWorkGroupSizeAttr(
*this, TemplateArgs, *AMDGPUFlatWorkGroupSize, New);
}
if (const auto *AMDGPUFlatWorkGroupSize =
dyn_cast<AMDGPUWavesPerEUAttr>(TmplAttr)) {
instantiateDependentAMDGPUWavesPerEUAttr(*this, TemplateArgs,
*AMDGPUFlatWorkGroupSize, New);
}
// Existing DLL attribute on the instantiation takes precedence.
if (TmplAttr->getKind() == attr::DLLExport ||
TmplAttr->getKind() == attr::DLLImport) {
if (New->hasAttr<DLLExportAttr>() || New->hasAttr<DLLImportAttr>()) {
continue;
}
}
if (const auto *ABIAttr = dyn_cast<ParameterABIAttr>(TmplAttr)) {
AddParameterABIAttr(New, *ABIAttr, ABIAttr->getABI());
continue;
}
if (isa<NSConsumedAttr>(TmplAttr) || isa<OSConsumedAttr>(TmplAttr) ||
isa<CFConsumedAttr>(TmplAttr)) {
AddXConsumedAttr(New, *TmplAttr, attrToRetainOwnershipKind(TmplAttr),
/*template instantiation=*/true);
continue;
}
if (auto *A = dyn_cast<PointerAttr>(TmplAttr)) {
if (!New->hasAttr<PointerAttr>())
New->addAttr(A->clone(Context));
continue;
}
if (auto *A = dyn_cast<OwnerAttr>(TmplAttr)) {
if (!New->hasAttr<OwnerAttr>())
New->addAttr(A->clone(Context));
continue;
}
assert(!TmplAttr->isPackExpansion());
if (TmplAttr->isLateParsed() && LateAttrs) {
// Late parsed attributes must be instantiated and attached after the
// enclosing class has been instantiated. See Sema::InstantiateClass.
LocalInstantiationScope *Saved = nullptr;
if (CurrentInstantiationScope)
Saved = CurrentInstantiationScope->cloneScopes(OuterMostScope);
LateAttrs->push_back(LateInstantiatedAttribute(TmplAttr, Saved, New));
} else {
// Allow 'this' within late-parsed attributes.
NamedDecl *ND = dyn_cast<NamedDecl>(New);
CXXRecordDecl *ThisContext =
dyn_cast_or_null<CXXRecordDecl>(ND->getDeclContext());
CXXThisScopeRAII ThisScope(*this, ThisContext, Qualifiers(),
ND && ND->isCXXInstanceMember());
Attr *NewAttr = sema::instantiateTemplateAttribute(TmplAttr, Context,
*this, TemplateArgs);
if (NewAttr)
New->addAttr(NewAttr);
}
}
}
/// Get the previous declaration of a declaration for the purposes of template
/// instantiation. If this finds a previous declaration, then the previous
/// declaration of the instantiation of D should be an instantiation of the
/// result of this function.
template<typename DeclT>
static DeclT *getPreviousDeclForInstantiation(DeclT *D) {
DeclT *Result = D->getPreviousDecl();
// If the declaration is within a class, and the previous declaration was
// merged from a different definition of that class, then we don't have a
// previous declaration for the purpose of template instantiation.
if (Result && isa<CXXRecordDecl>(D->getDeclContext()) &&
D->getLexicalDeclContext() != Result->getLexicalDeclContext())
return nullptr;
return Result;
}
Decl *
TemplateDeclInstantiator::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
llvm_unreachable("Translation units cannot be instantiated");
}
Decl *
TemplateDeclInstantiator::VisitPragmaCommentDecl(PragmaCommentDecl *D) {
llvm_unreachable("pragma comment cannot be instantiated");
}
Decl *TemplateDeclInstantiator::VisitPragmaDetectMismatchDecl(
PragmaDetectMismatchDecl *D) {
llvm_unreachable("pragma comment cannot be instantiated");
}
Decl *
TemplateDeclInstantiator::VisitExternCContextDecl(ExternCContextDecl *D) {
llvm_unreachable("extern \"C\" context cannot be instantiated");
}
Decl *
TemplateDeclInstantiator::VisitLabelDecl(LabelDecl *D) {
LabelDecl *Inst = LabelDecl::Create(SemaRef.Context, Owner, D->getLocation(),
D->getIdentifier());
Owner->addDecl(Inst);
return Inst;
}
Decl *
TemplateDeclInstantiator::VisitNamespaceDecl(NamespaceDecl *D) {
llvm_unreachable("Namespaces cannot be instantiated");
}
Decl *
TemplateDeclInstantiator::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
NamespaceAliasDecl *Inst
= NamespaceAliasDecl::Create(SemaRef.Context, Owner,
D->getNamespaceLoc(),
D->getAliasLoc(),
D->getIdentifier(),
D->getQualifierLoc(),
D->getTargetNameLoc(),
D->getNamespace());
Owner->addDecl(Inst);
return Inst;
}
Decl *TemplateDeclInstantiator::InstantiateTypedefNameDecl(TypedefNameDecl *D,
bool IsTypeAlias) {
bool Invalid = false;
TypeSourceInfo *DI = D->getTypeSourceInfo();
if (DI->getType()->isInstantiationDependentType() ||
DI->getType()->isVariablyModifiedType()) {
DI = SemaRef.SubstType(DI, TemplateArgs,
D->getLocation(), D->getDeclName());
if (!DI) {
Invalid = true;
DI = SemaRef.Context.getTrivialTypeSourceInfo(SemaRef.Context.IntTy);
}
} else {
SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
}
// HACK: g++ has a bug where it gets the value kind of ?: wrong.
// libstdc++ relies upon this bug in its implementation of common_type.
// If we happen to be processing that implementation, fake up the g++ ?:
// semantics. See LWG issue 2141 for more information on the bug.
const DecltypeType *DT = DI->getType()->getAs<DecltypeType>();
CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D->getDeclContext());
if (DT && RD && isa<ConditionalOperator>(DT->getUnderlyingExpr()) &&
DT->isReferenceType() &&
RD->getEnclosingNamespaceContext() == SemaRef.getStdNamespace() &&
RD->getIdentifier() && RD->getIdentifier()->isStr("common_type") &&
D->getIdentifier() && D->getIdentifier()->isStr("type") &&
SemaRef.getSourceManager().isInSystemHeader(D->getBeginLoc()))
// Fold it to the (non-reference) type which g++ would have produced.
DI = SemaRef.Context.getTrivialTypeSourceInfo(
DI->getType().getNonReferenceType());
// Create the new typedef
TypedefNameDecl *Typedef;
if (IsTypeAlias)
Typedef = TypeAliasDecl::Create(SemaRef.Context, Owner, D->getBeginLoc(),
D->getLocation(), D->getIdentifier(), DI);
else
Typedef = TypedefDecl::Create(SemaRef.Context, Owner, D->getBeginLoc(),
D->getLocation(), D->getIdentifier(), DI);
if (Invalid)
Typedef->setInvalidDecl();
// If the old typedef was the name for linkage purposes of an anonymous
// tag decl, re-establish that relationship for the new typedef.
if (const TagType *oldTagType = D->getUnderlyingType()->getAs<TagType>()) {
TagDecl *oldTag = oldTagType->getDecl();
if (oldTag->getTypedefNameForAnonDecl() == D && !Invalid) {
TagDecl *newTag = DI->getType()->castAs<TagType>()->getDecl();
assert(!newTag->hasNameForLinkage());
newTag->setTypedefNameForAnonDecl(Typedef);
}
}
if (TypedefNameDecl *Prev = getPreviousDeclForInstantiation(D)) {
NamedDecl *InstPrev = SemaRef.FindInstantiatedDecl(D->getLocation(), Prev,
TemplateArgs);
if (!InstPrev)
return nullptr;
TypedefNameDecl *InstPrevTypedef = cast<TypedefNameDecl>(InstPrev);
// If the typedef types are not identical, reject them.
SemaRef.isIncompatibleTypedef(InstPrevTypedef, Typedef);
Typedef->setPreviousDecl(InstPrevTypedef);
}
SemaRef.InstantiateAttrs(TemplateArgs, D, Typedef);
if (D->getUnderlyingType()->getAs<DependentNameType>())
SemaRef.inferGslPointerAttribute(Typedef);
Typedef->setAccess(D->getAccess());
return Typedef;
}
Decl *TemplateDeclInstantiator::VisitTypedefDecl(TypedefDecl *D) {
Decl *Typedef = InstantiateTypedefNameDecl(D, /*IsTypeAlias=*/false);
if (Typedef)
Owner->addDecl(Typedef);
return Typedef;
}
Decl *TemplateDeclInstantiator::VisitTypeAliasDecl(TypeAliasDecl *D) {
Decl *Typedef = InstantiateTypedefNameDecl(D, /*IsTypeAlias=*/true);
if (Typedef)
Owner->addDecl(Typedef);
return Typedef;
}
Decl *
TemplateDeclInstantiator::VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D) {
// Create a local instantiation scope for this type alias template, which
// will contain the instantiations of the template parameters.
LocalInstantiationScope Scope(SemaRef);
TemplateParameterList *TempParams = D->getTemplateParameters();
TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
if (!InstParams)
return nullptr;
TypeAliasDecl *Pattern = D->getTemplatedDecl();
TypeAliasTemplateDecl *PrevAliasTemplate = nullptr;
if (getPreviousDeclForInstantiation<TypedefNameDecl>(Pattern)) {
DeclContext::lookup_result Found = Owner->lookup(Pattern->getDeclName());
if (!Found.empty()) {
PrevAliasTemplate = dyn_cast<TypeAliasTemplateDecl>(Found.front());
}
}
TypeAliasDecl *AliasInst = cast_or_null<TypeAliasDecl>(
InstantiateTypedefNameDecl(Pattern, /*IsTypeAlias=*/true));
if (!AliasInst)
return nullptr;
TypeAliasTemplateDecl *Inst
= TypeAliasTemplateDecl::Create(SemaRef.Context, Owner, D->getLocation(),
D->getDeclName(), InstParams, AliasInst);
AliasInst->setDescribedAliasTemplate(Inst);
if (PrevAliasTemplate)
Inst->setPreviousDecl(PrevAliasTemplate);
Inst->setAccess(D->getAccess());
if (!PrevAliasTemplate)
Inst->setInstantiatedFromMemberTemplate(D);
Owner->addDecl(Inst);
return Inst;
}
Decl *TemplateDeclInstantiator::VisitBindingDecl(BindingDecl *D) {
auto *NewBD = BindingDecl::Create(SemaRef.Context, Owner, D->getLocation(),
D->getIdentifier());
NewBD->setReferenced(D->isReferenced());
SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, NewBD);
return NewBD;
}
Decl *TemplateDeclInstantiator::VisitDecompositionDecl(DecompositionDecl *D) {
// Transform the bindings first.
SmallVector<BindingDecl*, 16> NewBindings;
for (auto *OldBD : D->bindings())
NewBindings.push_back(cast<BindingDecl>(VisitBindingDecl(OldBD)));
ArrayRef<BindingDecl*> NewBindingArray = NewBindings;
auto *NewDD = cast_or_null<DecompositionDecl>(
VisitVarDecl(D, /*InstantiatingVarTemplate=*/false, &NewBindingArray));
if (!NewDD || NewDD->isInvalidDecl())
for (auto *NewBD : NewBindings)
NewBD->setInvalidDecl();
return NewDD;
}
Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D) {
return VisitVarDecl(D, /*InstantiatingVarTemplate=*/false);
}
Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D,
bool InstantiatingVarTemplate,
ArrayRef<BindingDecl*> *Bindings) {
// Do substitution on the type of the declaration
TypeSourceInfo *DI = SemaRef.SubstType(
D->getTypeSourceInfo(), TemplateArgs, D->getTypeSpecStartLoc(),
D->getDeclName(), /*AllowDeducedTST*/true);
if (!DI)
return nullptr;
if (DI->getType()->isFunctionType()) {
SemaRef.Diag(D->getLocation(), diag::err_variable_instantiates_to_function)
<< D->isStaticDataMember() << DI->getType();
return nullptr;
}
DeclContext *DC = Owner;
if (D->isLocalExternDecl())
SemaRef.adjustContextForLocalExternDecl(DC);
// Build the instantiated declaration.
VarDecl *Var;
if (Bindings)
Var = DecompositionDecl::Create(SemaRef.Context, DC, D->getInnerLocStart(),
D->getLocation(), DI->getType(), DI,
D->getStorageClass(), *Bindings);
else
Var = VarDecl::Create(SemaRef.Context, DC, D->getInnerLocStart(),
D->getLocation(), D->getIdentifier(), DI->getType(),
DI, D->getStorageClass());
// In ARC, infer 'retaining' for variables of retainable type.
if (SemaRef.getLangOpts().ObjCAutoRefCount &&
SemaRef.inferObjCARCLifetime(Var))
Var->setInvalidDecl();
// Substitute the nested name specifier, if any.
if (SubstQualifier(D, Var))
return nullptr;
SemaRef.BuildVariableInstantiation(Var, D, TemplateArgs, LateAttrs, Owner,
StartingScope, InstantiatingVarTemplate);
if (D->isNRVOVariable()) {
QualType ReturnType = cast<FunctionDecl>(DC)->getReturnType();
if (SemaRef.isCopyElisionCandidate(ReturnType, Var, Sema::CES_Strict))
Var->setNRVOVariable(true);
}
Var->setImplicit(D->isImplicit());
if (Var->isStaticLocal())
SemaRef.CheckStaticLocalForDllExport(Var);
return Var;
}
Decl *TemplateDeclInstantiator::VisitAccessSpecDecl(AccessSpecDecl *D) {
AccessSpecDecl* AD
= AccessSpecDecl::Create(SemaRef.Context, D->getAccess(), Owner,
D->getAccessSpecifierLoc(), D->getColonLoc());
Owner->addHiddenDecl(AD);
return AD;
}
Decl *TemplateDeclInstantiator::VisitFieldDecl(FieldDecl *D) {
bool Invalid = false;
TypeSourceInfo *DI = D->getTypeSourceInfo();
if (DI->getType()->isInstantiationDependentType() ||
DI->getType()->isVariablyModifiedType()) {
DI = SemaRef.SubstType(DI, TemplateArgs,
D->getLocation(), D->getDeclName());
if (!DI) {
DI = D->getTypeSourceInfo();
Invalid = true;
} else if (DI->getType()->isFunctionType()) {
// C++ [temp.arg.type]p3:
// If a declaration acquires a function type through a type
// dependent on a template-parameter and this causes a
// declaration that does not use the syntactic form of a
// function declarator to have function type, the program is
// ill-formed.
SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
<< DI->getType();
Invalid = true;
}
} else {
SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
}
Expr *BitWidth = D->getBitWidth();
if (Invalid)
BitWidth = nullptr;
else if (BitWidth) {
// The bit-width expression is a constant expression.
EnterExpressionEvaluationContext Unevaluated(
SemaRef, Sema::ExpressionEvaluationContext::ConstantEvaluated);
ExprResult InstantiatedBitWidth
= SemaRef.SubstExpr(BitWidth, TemplateArgs);
if (InstantiatedBitWidth.isInvalid()) {
Invalid = true;
BitWidth = nullptr;
} else
BitWidth = InstantiatedBitWidth.getAs<Expr>();
}
FieldDecl *Field = SemaRef.CheckFieldDecl(D->getDeclName(),
DI->getType(), DI,
cast<RecordDecl>(Owner),
D->getLocation(),
D->isMutable(),
BitWidth,
D->getInClassInitStyle(),
D->getInnerLocStart(),
D->getAccess(),
nullptr);
if (!Field) {
cast<Decl>(Owner)->setInvalidDecl();
return nullptr;
}
SemaRef.InstantiateAttrs(TemplateArgs, D, Field, LateAttrs, StartingScope);
if (Field->hasAttrs())
SemaRef.CheckAlignasUnderalignment(Field);
if (Invalid)
Field->setInvalidDecl();
if (!Field->getDeclName()) {
// Keep track of where this decl came from.
SemaRef.Context.setInstantiatedFromUnnamedFieldDecl(Field, D);
}
if (CXXRecordDecl *Parent= dyn_cast<CXXRecordDecl>(Field->getDeclContext())) {
if (Parent->isAnonymousStructOrUnion() &&
Parent->getRedeclContext()->isFunctionOrMethod())
SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Field);
}
Field->setImplicit(D->isImplicit());
Field->setAccess(D->getAccess());
Owner->addDecl(Field);
return Field;
}
Decl *TemplateDeclInstantiator::VisitMSPropertyDecl(MSPropertyDecl *D) {
bool Invalid = false;
TypeSourceInfo *DI = D->getTypeSourceInfo();
if (DI->getType()->isVariablyModifiedType()) {
SemaRef.Diag(D->getLocation(), diag::err_property_is_variably_modified)
<< D;
Invalid = true;
} else if (DI->getType()->isInstantiationDependentType()) {
DI = SemaRef.SubstType(DI, TemplateArgs,
D->getLocation(), D->getDeclName());
if (!DI) {
DI = D->getTypeSourceInfo();
Invalid = true;
} else if (DI->getType()->isFunctionType()) {
// C++ [temp.arg.type]p3:
// If a declaration acquires a function type through a type
// dependent on a template-parameter and this causes a
// declaration that does not use the syntactic form of a
// function declarator to have function type, the program is
// ill-formed.
SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
<< DI->getType();
Invalid = true;
}
} else {
SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
}
MSPropertyDecl *Property = MSPropertyDecl::Create(
SemaRef.Context, Owner, D->getLocation(), D->getDeclName(), DI->getType(),
DI, D->getBeginLoc(), D->getGetterId(), D->getSetterId());
SemaRef.InstantiateAttrs(TemplateArgs, D, Property, LateAttrs,
StartingScope);
if (Invalid)
Property->setInvalidDecl();
Property->setAccess(D->getAccess());
Owner->addDecl(Property);
return Property;
}
Decl *TemplateDeclInstantiator::VisitIndirectFieldDecl(IndirectFieldDecl *D) {
NamedDecl **NamedChain =
new (SemaRef.Context)NamedDecl*[D->getChainingSize()];
int i = 0;
for (auto *PI : D->chain()) {
NamedDecl *Next = SemaRef.FindInstantiatedDecl(D->getLocation(), PI,
TemplateArgs);
if (!Next)
return nullptr;
NamedChain[i++] = Next;
}
QualType T = cast<FieldDecl>(NamedChain[i-1])->getType();
IndirectFieldDecl *IndirectField = IndirectFieldDecl::Create(
SemaRef.Context, Owner, D->getLocation(), D->getIdentifier(), T,
{NamedChain, D->getChainingSize()});
for (const auto *Attr : D->attrs())
IndirectField->addAttr(Attr->clone(SemaRef.Context));
IndirectField->setImplicit(D->isImplicit());
IndirectField->setAccess(D->getAccess());
Owner->addDecl(IndirectField);
return IndirectField;
}
Decl *TemplateDeclInstantiator::VisitFriendDecl(FriendDecl *D) {
// Handle friend type expressions by simply substituting template
// parameters into the pattern type and checking the result.
if (TypeSourceInfo *Ty = D->getFriendType()) {
TypeSourceInfo *InstTy;
// If this is an unsupported friend, don't bother substituting template
// arguments into it. The actual type referred to won't be used by any
// parts of Clang, and may not be valid for instantiating. Just use the
// same info for the instantiated friend.
if (D->isUnsupportedFriend()) {
InstTy = Ty;
} else {
InstTy = SemaRef.SubstType(Ty, TemplateArgs,
D->getLocation(), DeclarationName());
}
if (!InstTy)
return nullptr;
FriendDecl *FD = SemaRef.CheckFriendTypeDecl(D->getBeginLoc(),
D->getFriendLoc(), InstTy);
if (!FD)
return nullptr;
FD->setAccess(AS_public);
FD->setUnsupportedFriend(D->isUnsupportedFriend());
Owner->addDecl(FD);
return FD;
}
NamedDecl *ND = D->getFriendDecl();
assert(ND && "friend decl must be a decl or a type!");
// All of the Visit implementations for the various potential friend
// declarations have to be carefully written to work for friend
// objects, with the most important detail being that the target
// decl should almost certainly not be placed in Owner.
Decl *NewND = Visit(ND);
if (!NewND) return nullptr;
FriendDecl *FD =
FriendDecl::Create(SemaRef.Context, Owner, D->getLocation(),
cast<NamedDecl>(NewND), D->getFriendLoc());
FD->setAccess(AS_public);
FD->setUnsupportedFriend(D->isUnsupportedFriend());
Owner->addDecl(FD);
return FD;
}
Decl *TemplateDeclInstantiator::VisitStaticAssertDecl(StaticAssertDecl *D) {
Expr *AssertExpr = D->getAssertExpr();
// The expression in a static assertion is a constant expression.
EnterExpressionEvaluationContext Unevaluated(
SemaRef, Sema::ExpressionEvaluationContext::ConstantEvaluated);
ExprResult InstantiatedAssertExpr
= SemaRef.SubstExpr(AssertExpr, TemplateArgs);
if (InstantiatedAssertExpr.isInvalid())
return nullptr;
return SemaRef.BuildStaticAssertDeclaration(D->getLocation(),
InstantiatedAssertExpr.get(),
D->getMessage(),
D->getRParenLoc(),
D->isFailed());
}
Decl *TemplateDeclInstantiator::VisitEnumDecl(EnumDecl *D) {
EnumDecl *PrevDecl = nullptr;
if (EnumDecl *PatternPrev = getPreviousDeclForInstantiation(D)) {
NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(),
PatternPrev,
TemplateArgs);
if (!Prev) return nullptr;
PrevDecl = cast<EnumDecl>(Prev);
}
EnumDecl *Enum =
EnumDecl::Create(SemaRef.Context, Owner, D->getBeginLoc(),
D->getLocation(), D->getIdentifier(), PrevDecl,
D->isScoped(), D->isScopedUsingClassTag(), D->isFixed());
if (D->isFixed()) {
if (TypeSourceInfo *TI = D->getIntegerTypeSourceInfo()) {
// If we have type source information for the underlying type, it means it
// has been explicitly set by the user. Perform substitution on it before
// moving on.
SourceLocation UnderlyingLoc = TI->getTypeLoc().getBeginLoc();
TypeSourceInfo *NewTI = SemaRef.SubstType(TI, TemplateArgs, UnderlyingLoc,
DeclarationName());
if (!NewTI || SemaRef.CheckEnumUnderlyingType(NewTI))
Enum->setIntegerType(SemaRef.Context.IntTy);
else
Enum->setIntegerTypeSourceInfo(NewTI);
} else {
assert(!D->getIntegerType()->isDependentType()
&& "Dependent type without type source info");
Enum->setIntegerType(D->getIntegerType());
}
}
SemaRef.InstantiateAttrs(TemplateArgs, D, Enum);
Enum->setInstantiationOfMemberEnum(D, TSK_ImplicitInstantiation);
Enum->setAccess(D->getAccess());
// Forward the mangling number from the template to the instantiated decl.
SemaRef.Context.setManglingNumber(Enum, SemaRef.Context.getManglingNumber(D));
// See if the old tag was defined along with a declarator.
// If it did, mark the new tag as being associated with that declarator.
if (DeclaratorDecl *DD = SemaRef.Context.getDeclaratorForUnnamedTagDecl(D))
SemaRef.Context.addDeclaratorForUnnamedTagDecl(Enum, DD);
// See if the old tag was defined along with a typedef.
// If it did, mark the new tag as being associated with that typedef.
if (TypedefNameDecl *TND = SemaRef.Context.getTypedefNameForUnnamedTagDecl(D))
SemaRef.Context.addTypedefNameForUnnamedTagDecl(Enum, TND);
if (SubstQualifier(D, Enum)) return nullptr;
Owner->addDecl(Enum);
EnumDecl *Def = D->getDefinition();
if (Def && Def != D) {
// If this is an out-of-line definition of an enum member template, check
// that the underlying types match in the instantiation of both
// declarations.
if (TypeSourceInfo *TI = Def->getIntegerTypeSourceInfo()) {
SourceLocation UnderlyingLoc = TI->getTypeLoc().getBeginLoc();
QualType DefnUnderlying =
SemaRef.SubstType(TI->getType(), TemplateArgs,
UnderlyingLoc, DeclarationName());
SemaRef.CheckEnumRedeclaration(Def->getLocation(), Def->isScoped(),
DefnUnderlying, /*IsFixed=*/true, Enum);
}
}
// C++11 [temp.inst]p1: The implicit instantiation of a class template
// specialization causes the implicit instantiation of the declarations, but
// not the definitions of scoped member enumerations.
//
// DR1484 clarifies that enumeration definitions inside of a template
// declaration aren't considered entities that can be separately instantiated
// from the rest of the entity they are declared inside of.
if (isDeclWithinFunction(D) ? D == Def : Def && !Enum->isScoped()) {
SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Enum);
InstantiateEnumDefinition(Enum, Def);
}
return Enum;
}
void TemplateDeclInstantiator::InstantiateEnumDefinition(
EnumDecl *Enum, EnumDecl *Pattern) {
Enum->startDefinition();
// Update the location to refer to the definition.
Enum->setLocation(Pattern->getLocation());
SmallVector<Decl*, 4> Enumerators;
EnumConstantDecl *LastEnumConst = nullptr;
for (auto *EC : Pattern->enumerators()) {
// The specified value for the enumerator.
ExprResult Value((Expr *)nullptr);
if (Expr *UninstValue = EC->getInitExpr()) {
// The enumerator's value expression is a constant expression.
EnterExpressionEvaluationContext Unevaluated(
SemaRef, Sema::ExpressionEvaluationContext::ConstantEvaluated);
Value = SemaRef.SubstExpr(UninstValue, TemplateArgs);
}
// Drop the initial value and continue.
bool isInvalid = false;
if (Value.isInvalid()) {
Value = nullptr;
isInvalid = true;
}
EnumConstantDecl *EnumConst
= SemaRef.CheckEnumConstant(Enum, LastEnumConst,
EC->getLocation(), EC->getIdentifier(),
Value.get());
if (isInvalid) {
if (EnumConst)
EnumConst->setInvalidDecl();
Enum->setInvalidDecl();
}
if (EnumConst) {
SemaRef.InstantiateAttrs(TemplateArgs, EC, EnumConst);
EnumConst->setAccess(Enum->getAccess());
Enum->addDecl(EnumConst);
Enumerators.push_back(EnumConst);
LastEnumConst = EnumConst;
if (Pattern->getDeclContext()->isFunctionOrMethod() &&
!Enum->isScoped()) {
// If the enumeration is within a function or method, record the enum
// constant as a local.
SemaRef.CurrentInstantiationScope->InstantiatedLocal(EC, EnumConst);
}
}
}
SemaRef.ActOnEnumBody(Enum->getLocation(), Enum->getBraceRange(), Enum,
Enumerators, nullptr, ParsedAttributesView());
}
Decl *TemplateDeclInstantiator::VisitEnumConstantDecl(EnumConstantDecl *D) {
llvm_unreachable("EnumConstantDecls can only occur within EnumDecls.");
}
Decl *
TemplateDeclInstantiator::VisitBuiltinTemplateDecl(BuiltinTemplateDecl *D) {
llvm_unreachable("BuiltinTemplateDecls cannot be instantiated.");
}
Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
bool isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
// Create a local instantiation scope for this class template, which
// will contain the instantiations of the template parameters.
LocalInstantiationScope Scope(SemaRef);
TemplateParameterList *TempParams = D->getTemplateParameters();
TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
if (!InstParams)
return nullptr;
CXXRecordDecl *Pattern = D->getTemplatedDecl();
// Instantiate the qualifier. We have to do this first in case
// we're a friend declaration, because if we are then we need to put
// the new declaration in the appropriate context.
NestedNameSpecifierLoc QualifierLoc = Pattern->getQualifierLoc();
if (QualifierLoc) {
QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc,
TemplateArgs);
if (!QualifierLoc)
return nullptr;
}
CXXRecordDecl *PrevDecl = nullptr;
ClassTemplateDecl *PrevClassTemplate = nullptr;
if (!isFriend && getPreviousDeclForInstantiation(Pattern)) {
DeclContext::lookup_result Found = Owner->lookup(Pattern->getDeclName());
if (!Found.empty()) {
PrevClassTemplate = dyn_cast<ClassTemplateDecl>(Found.front());
if (PrevClassTemplate)
PrevDecl = PrevClassTemplate->getTemplatedDecl();
}
}
// If this isn't a friend, then it's a member template, in which
// case we just want to build the instantiation in the
// specialization. If it is a friend, we want to build it in
// the appropriate context.
DeclContext *DC = Owner;
if (isFriend) {
if (QualifierLoc) {
CXXScopeSpec SS;
SS.Adopt(QualifierLoc);
DC = SemaRef.computeDeclContext(SS);
if (!DC) return nullptr;
} else {
DC = SemaRef.FindInstantiatedContext(Pattern->getLocation(),
Pattern->getDeclContext(),
TemplateArgs);
}
// Look for a previous declaration of the template in the owning
// context.
LookupResult R(SemaRef, Pattern->getDeclName(), Pattern->getLocation(),
Sema::LookupOrdinaryName,
SemaRef.forRedeclarationInCurContext());
SemaRef.LookupQualifiedName(R, DC);
if (R.isSingleResult()) {
PrevClassTemplate = R.getAsSingle<ClassTemplateDecl>();
if (PrevClassTemplate)
PrevDecl = PrevClassTemplate->getTemplatedDecl();
}
if (!PrevClassTemplate && QualifierLoc) {
SemaRef.Diag(Pattern->getLocation(), diag::err_not_tag_in_scope)
<< D->getTemplatedDecl()->getTagKind() << Pattern->getDeclName() << DC
<< QualifierLoc.getSourceRange();
return nullptr;
}
bool AdoptedPreviousTemplateParams = false;
if (PrevClassTemplate) {
bool Complain = true;
// HACK: libstdc++ 4.2.1 contains an ill-formed friend class
// template for struct std::tr1::__detail::_Map_base, where the
// template parameters of the friend declaration don't match the
// template parameters of the original declaration. In this one
// case, we don't complain about the ill-formed friend
// declaration.
if (isFriend && Pattern->getIdentifier() &&
Pattern->getIdentifier()->isStr("_Map_base") &&
DC->isNamespace() &&
cast<NamespaceDecl>(DC)->getIdentifier() &&
cast<NamespaceDecl>(DC)->getIdentifier()->isStr("__detail")) {
DeclContext *DCParent = DC->getParent();
if (DCParent->isNamespace() &&
cast<NamespaceDecl>(DCParent)->getIdentifier() &&
cast<NamespaceDecl>(DCParent)->getIdentifier()->isStr("tr1")) {
if (cast<Decl>(DCParent)->isInStdNamespace())
Complain = false;
}
}
TemplateParameterList *PrevParams
= PrevClassTemplate->getMostRecentDecl()->getTemplateParameters();
// Make sure the parameter lists match.
if (!SemaRef.TemplateParameterListsAreEqual(InstParams, PrevParams,
Complain,
Sema::TPL_TemplateMatch)) {
if (Complain)
return nullptr;
AdoptedPreviousTemplateParams = true;
InstParams = PrevParams;
}
// Do some additional validation, then merge default arguments
// from the existing declarations.
if (!AdoptedPreviousTemplateParams &&
SemaRef.CheckTemplateParameterList(InstParams, PrevParams,
Sema::TPC_ClassTemplate))
return nullptr;
}
}
CXXRecordDecl *RecordInst = CXXRecordDecl::Create(
SemaRef.Context, Pattern->getTagKind(), DC, Pattern->getBeginLoc(),
Pattern->getLocation(), Pattern->getIdentifier(), PrevDecl,
/*DelayTypeCreation=*/true);
if (QualifierLoc)
RecordInst->setQualifierInfo(QualifierLoc);
SemaRef.InstantiateAttrsForDecl(TemplateArgs, Pattern, RecordInst, LateAttrs,
StartingScope);
ClassTemplateDecl *Inst
= ClassTemplateDecl::Create(SemaRef.Context, DC, D->getLocation(),
D->getIdentifier(), InstParams, RecordInst);
assert(!(isFriend && Owner->isDependentContext()));
Inst->setPreviousDecl(PrevClassTemplate);
RecordInst->setDescribedClassTemplate(Inst);
if (isFriend) {
if (PrevClassTemplate)
Inst->setAccess(PrevClassTemplate->getAccess());
else
Inst->setAccess(D->getAccess());
Inst->setObjectOfFriendDecl();
// TODO: do we want to track the instantiation progeny of this
// friend target decl?
} else {
Inst->setAccess(D->getAccess());
if (!PrevClassTemplate)
Inst->setInstantiatedFromMemberTemplate(D);
}
// Trigger creation of the type for the instantiation.
SemaRef.Context.getInjectedClassNameType(RecordInst,
Inst->getInjectedClassNameSpecialization());
// Finish handling of friends.
if (isFriend) {
DC->makeDeclVisibleInContext(Inst);
Inst->setLexicalDeclContext(Owner);
RecordInst->setLexicalDeclContext(Owner);
return Inst;
}
if (D->isOutOfLine()) {
Inst->setLexicalDeclContext(D->getLexicalDeclContext());
RecordInst->setLexicalDeclContext(D->getLexicalDeclContext());
}
Owner->addDecl(Inst);
if (!PrevClassTemplate) {
// Queue up any out-of-line partial specializations of this member
// class template; the client will force their instantiation once
// the enclosing class has been instantiated.
SmallVector<ClassTemplatePartialSpecializationDecl *, 4> PartialSpecs;
D->getPartialSpecializations(PartialSpecs);
for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
if (PartialSpecs[I]->getFirstDecl()->isOutOfLine())
OutOfLinePartialSpecs.push_back(std::make_pair(Inst, PartialSpecs[I]));
}
return Inst;
}
Decl *
TemplateDeclInstantiator::VisitClassTemplatePartialSpecializationDecl(
ClassTemplatePartialSpecializationDecl *D) {
ClassTemplateDecl *ClassTemplate = D->getSpecializedTemplate();
// Lookup the already-instantiated declaration in the instantiation
// of the class template and return that.
DeclContext::lookup_result Found
= Owner->lookup(ClassTemplate->getDeclName());
if (Found.empty())
return nullptr;
ClassTemplateDecl *InstClassTemplate
= dyn_cast<ClassTemplateDecl>(Found.front());
if (!InstClassTemplate)
return nullptr;
if (ClassTemplatePartialSpecializationDecl *Result
= InstClassTemplate->findPartialSpecInstantiatedFromMember(D))
return Result;
return InstantiateClassTemplatePartialSpecialization(InstClassTemplate, D);
}
Decl *TemplateDeclInstantiator::VisitVarTemplateDecl(VarTemplateDecl *D) {
assert(D->getTemplatedDecl()->isStaticDataMember() &&
"Only static data member templates are allowed.");
// Create a local instantiation scope for this variable template, which
// will contain the instantiations of the template parameters.
LocalInstantiationScope Scope(SemaRef);
TemplateParameterList *TempParams = D->getTemplateParameters();
TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
if (!InstParams)
return nullptr;
VarDecl *Pattern = D->getTemplatedDecl();
VarTemplateDecl *PrevVarTemplate = nullptr;
if (getPreviousDeclForInstantiation(Pattern)) {
DeclContext::lookup_result Found = Owner->lookup(Pattern->getDeclName());
if (!Found.empty())
PrevVarTemplate = dyn_cast<VarTemplateDecl>(Found.front());
}
VarDecl *VarInst =
cast_or_null<VarDecl>(VisitVarDecl(Pattern,
/*InstantiatingVarTemplate=*/true));
if (!VarInst) return nullptr;
DeclContext *DC = Owner;
VarTemplateDecl *Inst = VarTemplateDecl::Create(
SemaRef.Context, DC, D->getLocation(), D->getIdentifier(), InstParams,
VarInst);
VarInst->setDescribedVarTemplate(Inst);
Inst->setPreviousDecl(PrevVarTemplate);
Inst->setAccess(D->getAccess());
if (!PrevVarTemplate)
Inst->setInstantiatedFromMemberTemplate(D);
if (D->isOutOfLine()) {
Inst->setLexicalDeclContext(D->getLexicalDeclContext());
VarInst->setLexicalDeclContext(D->getLexicalDeclContext());
}
Owner->addDecl(Inst);
if (!PrevVarTemplate) {
// Queue up any out-of-line partial specializations of this member
// variable template; the client will force their instantiation once
// the enclosing class has been instantiated.
SmallVector<VarTemplatePartialSpecializationDecl *, 4> PartialSpecs;
D->getPartialSpecializations(PartialSpecs);
for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
if (PartialSpecs[I]->getFirstDecl()->isOutOfLine())
OutOfLineVarPartialSpecs.push_back(
std::make_pair(Inst, PartialSpecs[I]));
}
return Inst;
}
Decl *TemplateDeclInstantiator::VisitVarTemplatePartialSpecializationDecl(
VarTemplatePartialSpecializationDecl *D) {
assert(D->isStaticDataMember() &&
"Only static data member templates are allowed.");
VarTemplateDecl *VarTemplate = D->getSpecializedTemplate();
// Lookup the already-instantiated declaration and return that.
DeclContext::lookup_result Found = Owner->lookup(VarTemplate->getDeclName());
assert(!Found.empty() && "Instantiation found nothing?");
VarTemplateDecl *InstVarTemplate = dyn_cast<VarTemplateDecl>(Found.front());
assert(InstVarTemplate && "Instantiation did not find a variable template?");
if (VarTemplatePartialSpecializationDecl *Result =
InstVarTemplate->findPartialSpecInstantiatedFromMember(D))
return Result;
return InstantiateVarTemplatePartialSpecialization(InstVarTemplate, D);
}
Decl *
TemplateDeclInstantiator::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
// Create a local instantiation scope for this function template, which
// will contain the instantiations of the template parameters and then get
// merged with the local instantiation scope for the function template
// itself.
LocalInstantiationScope Scope(SemaRef);
TemplateParameterList *TempParams = D->getTemplateParameters();
TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
if (!InstParams)
return nullptr;
FunctionDecl *Instantiated = nullptr;
if (CXXMethodDecl *DMethod = dyn_cast<CXXMethodDecl>(D->getTemplatedDecl()))
Instantiated = cast_or_null<FunctionDecl>(VisitCXXMethodDecl(DMethod,
InstParams));
else
Instantiated = cast_or_null<FunctionDecl>(VisitFunctionDecl(
D->getTemplatedDecl(),
InstParams));
if (!Instantiated)
return nullptr;
// Link the instantiated function template declaration to the function
// template from which it was instantiated.
FunctionTemplateDecl *InstTemplate
= Instantiated->getDescribedFunctionTemplate();
InstTemplate->setAccess(D->getAccess());
assert(InstTemplate &&
"VisitFunctionDecl/CXXMethodDecl didn't create a template!");
bool isFriend = (InstTemplate->getFriendObjectKind() != Decl::FOK_None);
// Link the instantiation back to the pattern *unless* this is a
// non-definition friend declaration.
if (!InstTemplate->getInstantiatedFromMemberTemplate() &&
!(isFriend && !D->getTemplatedDecl()->isThisDeclarationADefinition()))
InstTemplate->setInstantiatedFromMemberTemplate(D);
// Make declarations visible in the appropriate context.
if (!isFriend) {
Owner->addDecl(InstTemplate);
} else if (InstTemplate->getDeclContext()->isRecord() &&
!getPreviousDeclForInstantiation(D)) {
SemaRef.CheckFriendAccess(InstTemplate);
}
return InstTemplate;
}
Decl *TemplateDeclInstantiator::VisitCXXRecordDecl(CXXRecordDecl *D) {
CXXRecordDecl *PrevDecl = nullptr;
if (D->isInjectedClassName())
PrevDecl = cast<CXXRecordDecl>(Owner);
else if (CXXRecordDecl *PatternPrev = getPreviousDeclForInstantiation(D)) {
NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(),
PatternPrev,
TemplateArgs);
if (!Prev) return nullptr;
PrevDecl = cast<CXXRecordDecl>(Prev);
}
CXXRecordDecl *Record = CXXRecordDecl::Create(
SemaRef.Context, D->getTagKind(), Owner, D->getBeginLoc(),
D->getLocation(), D->getIdentifier(), PrevDecl);
// Substitute the nested name specifier, if any.
if (SubstQualifier(D, Record))
return nullptr;
SemaRef.InstantiateAttrsForDecl(TemplateArgs, D, Record, LateAttrs,
StartingScope);
Record->setImplicit(D->isImplicit());
// FIXME: Check against AS_none is an ugly hack to work around the issue that
// the tag decls introduced by friend class declarations don't have an access
// specifier. Remove once this area of the code gets sorted out.
if (D->getAccess() != AS_none)
Record->setAccess(D->getAccess());
if (!D->isInjectedClassName())
Record->setInstantiationOfMemberClass(D, TSK_ImplicitInstantiation);
// If the original function was part of a friend declaration,
// inherit its namespace state.
if (D->getFriendObjectKind())
Record->setObjectOfFriendDecl();
// Make sure that anonymous structs and unions are recorded.
if (D->isAnonymousStructOrUnion())
Record->setAnonymousStructOrUnion(true);
if (D->isLocalClass())
SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Record);
// Forward the mangling number from the template to the instantiated decl.
SemaRef.Context.setManglingNumber(Record,
SemaRef.Context.getManglingNumber(D));
// See if the old tag was defined along with a declarator.
// If it did, mark the new tag as being associated with that declarator.
if (DeclaratorDecl *DD = SemaRef.Context.getDeclaratorForUnnamedTagDecl(D))
SemaRef.Context.addDeclaratorForUnnamedTagDecl(Record, DD);
// See if the old tag was defined along with a typedef.
// If it did, mark the new tag as being associated with that typedef.
if (TypedefNameDecl *TND = SemaRef.Context.getTypedefNameForUnnamedTagDecl(D))
SemaRef.Context.addTypedefNameForUnnamedTagDecl(Record, TND);
Owner->addDecl(Record);
// DR1484 clarifies that the members of a local class are instantiated as part
// of the instantiation of their enclosing entity.
if (D->isCompleteDefinition() && D->isLocalClass()) {
Sema::LocalEagerInstantiationScope LocalInstantiations(SemaRef);
SemaRef.InstantiateClass(D->getLocation(), Record, D, TemplateArgs,
TSK_ImplicitInstantiation,
/*Complain=*/true);
// For nested local classes, we will instantiate the members when we
// reach the end of the outermost (non-nested) local class.
if (!D->isCXXClassMember())
SemaRef.InstantiateClassMembers(D->getLocation(), Record, TemplateArgs,
TSK_ImplicitInstantiation);
// This class may have local implicit instantiations that need to be
// performed within this scope.
LocalInstantiations.perform();
}
SemaRef.DiagnoseUnusedNestedTypedefs(Record);
return Record;
}
/// Adjust the given function type for an instantiation of the
/// given declaration, to cope with modifications to the function's type that
/// aren't reflected in the type-source information.
///
/// \param D The declaration we're instantiating.
/// \param TInfo The already-instantiated type.
static QualType adjustFunctionTypeForInstantiation(ASTContext &Context,
FunctionDecl *D,
TypeSourceInfo *TInfo) {
const FunctionProtoType *OrigFunc
= D->getType()->castAs<FunctionProtoType>();
const FunctionProtoType *NewFunc
= TInfo->getType()->castAs<FunctionProtoType>();
if (OrigFunc->getExtInfo() == NewFunc->getExtInfo())
return TInfo->getType();
FunctionProtoType::ExtProtoInfo NewEPI = NewFunc->getExtProtoInfo();
NewEPI.ExtInfo = OrigFunc->getExtInfo();
return Context.getFunctionType(NewFunc->getReturnType(),
NewFunc->getParamTypes(), NewEPI);
}
/// Normal class members are of more specific types and therefore
/// don't make it here. This function serves three purposes:
/// 1) instantiating function templates
/// 2) substituting friend declarations
/// 3) substituting deduction guide declarations for nested class templates
Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D,
TemplateParameterList *TemplateParams) {
// Check whether there is already a function template specialization for
// this declaration.
FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
if (FunctionTemplate && !TemplateParams) {
ArrayRef<TemplateArgument> Innermost = TemplateArgs.getInnermost();
void *InsertPos = nullptr;
FunctionDecl *SpecFunc
= FunctionTemplate->findSpecialization(Innermost, InsertPos);
// If we already have a function template specialization, return it.
if (SpecFunc)
return SpecFunc;
}
bool isFriend;
if (FunctionTemplate)
isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
else
isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
bool MergeWithParentScope = (TemplateParams != nullptr) ||
Owner->isFunctionOrMethod() ||
!(isa<Decl>(Owner) &&
cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
ExplicitSpecifier InstantiatedExplicitSpecifier;
if (auto *DGuide = dyn_cast<CXXDeductionGuideDecl>(D)) {
InstantiatedExplicitSpecifier = instantiateExplicitSpecifier(
SemaRef, TemplateArgs, DGuide->getExplicitSpecifier(), DGuide);
if (InstantiatedExplicitSpecifier.isInvalid())
return nullptr;
}
SmallVector<ParmVarDecl *, 4> Params;
TypeSourceInfo *TInfo = SubstFunctionType(D, Params);
if (!TInfo)
return nullptr;
QualType T = adjustFunctionTypeForInstantiation(SemaRef.Context, D, TInfo);
NestedNameSpecifierLoc QualifierLoc = D->getQualifierLoc();
if (QualifierLoc) {
QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc,
TemplateArgs);
if (!QualifierLoc)
return nullptr;
}
// If we're instantiating a local function declaration, put the result
// in the enclosing namespace; otherwise we need to find the instantiated
// context.
DeclContext *DC;
if (D->isLocalExternDecl()) {
DC = Owner;
SemaRef.adjustContextForLocalExternDecl(DC);
} else if (isFriend && QualifierLoc) {
CXXScopeSpec SS;
SS.Adopt(QualifierLoc);
DC = SemaRef.computeDeclContext(SS);
if (!DC) return nullptr;
} else {
DC = SemaRef.FindInstantiatedContext(D->getLocation(), D->getDeclContext(),
TemplateArgs);
}
DeclarationNameInfo NameInfo
= SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
FunctionDecl *Function;
if (auto *DGuide = dyn_cast<CXXDeductionGuideDecl>(D)) {
Function = CXXDeductionGuideDecl::Create(
SemaRef.Context, DC, D->getInnerLocStart(),
InstantiatedExplicitSpecifier, NameInfo, T, TInfo,
D->getSourceRange().getEnd());
if (DGuide->isCopyDeductionCandidate())
cast<CXXDeductionGuideDecl>(Function)->setIsCopyDeductionCandidate();
Function->setAccess(D->getAccess());
} else {
Function = FunctionDecl::Create(
SemaRef.Context, DC, D->getInnerLocStart(), NameInfo, T, TInfo,
D->getCanonicalDecl()->getStorageClass(), D->isInlineSpecified(),
D->hasWrittenPrototype(), D->getConstexprKind());
Function->setRangeEnd(D->getSourceRange().getEnd());
}
if (D->isInlined())
Function->setImplicitlyInline();
if (QualifierLoc)
Function->setQualifierInfo(QualifierLoc);
if (D->isLocalExternDecl())
Function->setLocalExternDecl();
DeclContext *LexicalDC = Owner;
if (!isFriend && D->isOutOfLine() && !D->isLocalExternDecl()) {
assert(D->getDeclContext()->isFileContext());
LexicalDC = D->getDeclContext();
}
Function->setLexicalDeclContext(LexicalDC);
// Attach the parameters
for (unsigned P = 0; P < Params.size(); ++P)
if (Params[P])
Params[P]->setOwningFunction(Function);
Function->setParams(Params);
if (TemplateParams) {
// Our resulting instantiation is actually a function template, since we
// are substituting only the outer template parameters. For example, given
//
// template<typename T>
// struct X {
// template<typename U> friend void f(T, U);
// };
//
// X<int> x;
//
// We are instantiating the friend function template "f" within X<int>,
// which means substituting int for T, but leaving "f" as a friend function
// template.
// Build the function template itself.
FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, DC,
Function->getLocation(),
Function->getDeclName(),
TemplateParams, Function);
Function->setDescribedFunctionTemplate(FunctionTemplate);
FunctionTemplate->setLexicalDeclContext(LexicalDC);
if (isFriend && D->isThisDeclarationADefinition()) {
FunctionTemplate->setInstantiatedFromMemberTemplate(
D->getDescribedFunctionTemplate());
}
} else if (FunctionTemplate) {
// Record this function template specialization.
ArrayRef<TemplateArgument> Innermost = TemplateArgs.getInnermost();
Function->setFunctionTemplateSpecialization(FunctionTemplate,
TemplateArgumentList::CreateCopy(SemaRef.Context,
Innermost),
/*InsertPos=*/nullptr);
} else if (isFriend && D->isThisDeclarationADefinition()) {
// Do not connect the friend to the template unless it's actually a
// definition. We don't want non-template functions to be marked as being
// template instantiations.
Function->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
}
if (isFriend)
Function->setObjectOfFriendDecl();
if (InitFunctionInstantiation(Function, D))
Function->setInvalidDecl();
bool IsExplicitSpecialization = false;
LookupResult Previous(
SemaRef, Function->getDeclName(), SourceLocation(),
D->isLocalExternDecl() ? Sema::LookupRedeclarationWithLinkage
: Sema::LookupOrdinaryName,
D->isLocalExternDecl() ? Sema::ForExternalRedeclaration
: SemaRef.forRedeclarationInCurContext());
if (DependentFunctionTemplateSpecializationInfo *Info
= D->getDependentSpecializationInfo()) {
assert(isFriend && "non-friend has dependent specialization info?");
// Instantiate the explicit template arguments.
TemplateArgumentListInfo ExplicitArgs(Info->getLAngleLoc(),
Info->getRAngleLoc());
if (SemaRef.Subst(Info->getTemplateArgs(), Info->getNumTemplateArgs(),
ExplicitArgs, TemplateArgs))
return nullptr;
// Map the candidate templates to their instantiations.
for (unsigned I = 0, E = Info->getNumTemplates(); I != E; ++I) {
Decl *Temp = SemaRef.FindInstantiatedDecl(D->getLocation(),
Info->getTemplate(I),
TemplateArgs);
if (!Temp) return nullptr;
Previous.addDecl(cast<FunctionTemplateDecl>(Temp));
}
if (SemaRef.CheckFunctionTemplateSpecialization(Function,
&ExplicitArgs,
Previous))
Function->setInvalidDecl();
IsExplicitSpecialization = true;
} else if (const ASTTemplateArgumentListInfo *Info =
D->getTemplateSpecializationArgsAsWritten()) {
// The name of this function was written as a template-id.
SemaRef.LookupQualifiedName(Previous, DC);
// Instantiate the explicit template arguments.
TemplateArgumentListInfo ExplicitArgs(Info->getLAngleLoc(),
Info->getRAngleLoc());
if (SemaRef.Subst(Info->getTemplateArgs(), Info->getNumTemplateArgs(),
ExplicitArgs, TemplateArgs))
return nullptr;
if (SemaRef.CheckFunctionTemplateSpecialization(Function,
&ExplicitArgs,
Previous))
Function->setInvalidDecl();
IsExplicitSpecialization = true;
} else if (TemplateParams || !FunctionTemplate) {
// Look only into the namespace where the friend would be declared to
// find a previous declaration. This is the innermost enclosing namespace,
// as described in ActOnFriendFunctionDecl.
SemaRef.LookupQualifiedName(Previous, DC);
// In C++, the previous declaration we find might be a tag type
// (class or enum). In this case, the new declaration will hide the
// tag type. Note that this does does not apply if we're declaring a
// typedef (C++ [dcl.typedef]p4).
if (Previous.isSingleTagDecl())
Previous.clear();
}
SemaRef.CheckFunctionDeclaration(/*Scope*/ nullptr, Function, Previous,
IsExplicitSpecialization);
NamedDecl *PrincipalDecl = (TemplateParams
? cast<NamedDecl>(FunctionTemplate)
: Function);
// If the original function was part of a friend declaration,
// inherit its namespace state and add it to the owner.
if (isFriend) {
Function->setObjectOfFriendDecl();
if (FunctionTemplateDecl *FT = Function->getDescribedFunctionTemplate())
FT->setObjectOfFriendDecl();
DC->makeDeclVisibleInContext(PrincipalDecl);
bool QueuedInstantiation = false;
// C++11 [temp.friend]p4 (DR329):
// When a function is defined in a friend function declaration in a class
// template, the function is instantiated when the function is odr-used.
// The same restrictions on multiple declarations and definitions that
// apply to non-template function declarations and definitions also apply
// to these implicit definitions.
if (D->isThisDeclarationADefinition()) {
SemaRef.CheckForFunctionRedefinition(Function);
if (!Function->isInvalidDecl()) {
for (auto R : Function->redecls()) {
if (R == Function)
continue;
// If some prior declaration of this function has been used, we need
// to instantiate its definition.
if (!QueuedInstantiation && R->isUsed(false)) {
if (MemberSpecializationInfo *MSInfo =
Function->getMemberSpecializationInfo()) {
if (MSInfo->getPointOfInstantiation().isInvalid()) {
SourceLocation Loc = R->getLocation(); // FIXME
MSInfo->setPointOfInstantiation(Loc);
SemaRef.PendingLocalImplicitInstantiations.push_back(
std::make_pair(Function, Loc));
QueuedInstantiation = true;
}
}
}
}
}
}
// Check the template parameter list against the previous declaration. The
// goal here is to pick up default arguments added since the friend was
// declared; we know the template parameter lists match, since otherwise
// we would not have picked this template as the previous declaration.
if (TemplateParams && FunctionTemplate->getPreviousDecl()) {
SemaRef.CheckTemplateParameterList(
TemplateParams,
FunctionTemplate->getPreviousDecl()->getTemplateParameters(),
Function->isThisDeclarationADefinition()
? Sema::TPC_FriendFunctionTemplateDefinition
: Sema::TPC_FriendFunctionTemplate);
}
}
if (Function->isLocalExternDecl() && !Function->getPreviousDecl())
DC->makeDeclVisibleInContext(PrincipalDecl);
if (Function->isOverloadedOperator() && !DC->isRecord() &&
PrincipalDecl->isInIdentifierNamespace(Decl::IDNS_Ordinary))
PrincipalDecl->setNonMemberOperator();
assert(!D->isDefaulted() && "only methods should be defaulted");
return Function;
}
Decl *TemplateDeclInstantiator::VisitCXXMethodDecl(
CXXMethodDecl *D, TemplateParameterList *TemplateParams,
Optional<const ASTTemplateArgumentListInfo *>
ClassScopeSpecializationArgs) {
FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
if (FunctionTemplate && !TemplateParams) {
// We are creating a function template specialization from a function
// template. Check whether there is already a function template
// specialization for this particular set of template arguments.
ArrayRef<TemplateArgument> Innermost = TemplateArgs.getInnermost();
void *InsertPos = nullptr;
FunctionDecl *SpecFunc
= FunctionTemplate->findSpecialization(Innermost, InsertPos);
// If we already have a function template specialization, return it.
if (SpecFunc)
return SpecFunc;
}
bool isFriend;
if (FunctionTemplate)
isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
else
isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
bool MergeWithParentScope = (TemplateParams != nullptr) ||
!(isa<Decl>(Owner) &&
cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
// Instantiate enclosing template arguments for friends.
SmallVector<TemplateParameterList *, 4> TempParamLists;
unsigned NumTempParamLists = 0;
if (isFriend && (NumTempParamLists = D->getNumTemplateParameterLists())) {
TempParamLists.resize(NumTempParamLists);
for (unsigned I = 0; I != NumTempParamLists; ++I) {
TemplateParameterList *TempParams = D->getTemplateParameterList(I);
TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
if (!InstParams)
return nullptr;
TempParamLists[I] = InstParams;
}
}
ExplicitSpecifier InstantiatedExplicitSpecifier =
instantiateExplicitSpecifier(SemaRef, TemplateArgs,
ExplicitSpecifier::getFromDecl(D), D);
if (InstantiatedExplicitSpecifier.isInvalid())
return nullptr;
SmallVector<ParmVarDecl *, 4> Params;
TypeSourceInfo *TInfo = SubstFunctionType(D, Params);
if (!TInfo)
return nullptr;
QualType T = adjustFunctionTypeForInstantiation(SemaRef.Context, D, TInfo);
NestedNameSpecifierLoc QualifierLoc = D->getQualifierLoc();
if (QualifierLoc) {
QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc,
TemplateArgs);
if (!QualifierLoc)
return nullptr;
}
DeclContext *DC = Owner;
if (isFriend) {
if (QualifierLoc) {
CXXScopeSpec SS;
SS.Adopt(QualifierLoc);
DC = SemaRef.computeDeclContext(SS);
if (DC && SemaRef.RequireCompleteDeclContext(SS, DC))
return nullptr;
} else {
DC = SemaRef.FindInstantiatedContext(D->getLocation(),
D->getDeclContext(),
TemplateArgs);
}
if (!DC) return nullptr;
}
// Build the instantiated method declaration.
CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
CXXMethodDecl *Method = nullptr;
SourceLocation StartLoc = D->getInnerLocStart();
DeclarationNameInfo NameInfo
= SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
Method = CXXConstructorDecl::Create(
SemaRef.Context, Record, StartLoc, NameInfo, T, TInfo,
InstantiatedExplicitSpecifier, Constructor->isInlineSpecified(), false,
Constructor->getConstexprKind());
Method->setRangeEnd(Constructor->getEndLoc());
} else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) {
Method = CXXDestructorDecl::Create(
SemaRef.Context, Record, StartLoc, NameInfo, T, TInfo,
Destructor->isInlineSpecified(), false, Destructor->getConstexprKind());
Method->setRangeEnd(Destructor->getEndLoc());
} else if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(D)) {
Method = CXXConversionDecl::Create(
SemaRef.Context, Record, StartLoc, NameInfo, T, TInfo,
Conversion->isInlineSpecified(), InstantiatedExplicitSpecifier,
Conversion->getConstexprKind(), Conversion->getEndLoc());
} else {
StorageClass SC = D->isStatic() ? SC_Static : SC_None;
Method = CXXMethodDecl::Create(SemaRef.Context, Record, StartLoc, NameInfo,
T, TInfo, SC, D->isInlineSpecified(),
D->getConstexprKind(), D->getEndLoc());
}
if (D->isInlined())
Method->setImplicitlyInline();
if (QualifierLoc)
Method->setQualifierInfo(QualifierLoc);
if (TemplateParams) {
// Our resulting instantiation is actually a function template, since we
// are substituting only the outer template parameters. For example, given
//
// template<typename T>
// struct X {
// template<typename U> void f(T, U);
// };
//
// X<int> x;
//
// We are instantiating the member template "f" within X<int>, which means
// substituting int for T, but leaving "f" as a member function template.
// Build the function template itself.
FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, Record,
Method->getLocation(),
Method->getDeclName(),
TemplateParams, Method);
if (isFriend) {
FunctionTemplate->setLexicalDeclContext(Owner);
FunctionTemplate->setObjectOfFriendDecl();
} else if (D->isOutOfLine())
FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext());
Method->setDescribedFunctionTemplate(FunctionTemplate);
} else if (FunctionTemplate) {
// Record this function template specialization.
ArrayRef<TemplateArgument> Innermost = TemplateArgs.getInnermost();
Method->setFunctionTemplateSpecialization(FunctionTemplate,
TemplateArgumentList::CreateCopy(SemaRef.Context,
Innermost),
/*InsertPos=*/nullptr);
} else if (!isFriend) {
// Record that this is an instantiation of a member function.
Method->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
}
// If we are instantiating a member function defined
// out-of-line, the instantiation will have the same lexical
// context (which will be a namespace scope) as the template.
if (isFriend) {
if (NumTempParamLists)
Method->setTemplateParameterListsInfo(
SemaRef.Context,
llvm::makeArrayRef(TempParamLists.data(), NumTempParamLists));
Method->setLexicalDeclContext(Owner);
Method->setObjectOfFriendDecl();
} else if (D->isOutOfLine())
Method->setLexicalDeclContext(D->getLexicalDeclContext());
// Attach the parameters
for (unsigned P = 0; P < Params.size(); ++P)
Params[P]->setOwningFunction(Method);
Method->setParams(Params);
if (InitMethodInstantiation(Method, D))
Method->setInvalidDecl();
LookupResult Previous(SemaRef, NameInfo, Sema::LookupOrdinaryName,
Sema::ForExternalRedeclaration);
bool IsExplicitSpecialization = false;
// If the name of this function was written as a template-id, instantiate
// the explicit template arguments.
if (DependentFunctionTemplateSpecializationInfo *Info
= D->getDependentSpecializationInfo()) {
assert(isFriend && "non-friend has dependent specialization info?");
// Instantiate the explicit template arguments.
TemplateArgumentListInfo ExplicitArgs(Info->getLAngleLoc(),
Info->getRAngleLoc());
if (SemaRef.Subst(Info->getTemplateArgs(), Info->getNumTemplateArgs(),
ExplicitArgs, TemplateArgs))
return nullptr;
// Map the candidate templates to their instantiations.
for (unsigned I = 0, E = Info->getNumTemplates(); I != E; ++I) {
Decl *Temp = SemaRef.FindInstantiatedDecl(D->getLocation(),
Info->getTemplate(I),
TemplateArgs);
if (!Temp) return nullptr;
Previous.addDecl(cast<FunctionTemplateDecl>(Temp));
}
if (SemaRef.CheckFunctionTemplateSpecialization(Method,
&ExplicitArgs,
Previous))
Method->setInvalidDecl();
IsExplicitSpecialization = true;
} else if (const ASTTemplateArgumentListInfo *Info =
ClassScopeSpecializationArgs.getValueOr(
D->getTemplateSpecializationArgsAsWritten())) {
SemaRef.LookupQualifiedName(Previous, DC);
TemplateArgumentListInfo ExplicitArgs(Info->getLAngleLoc(),
Info->getRAngleLoc());
if (SemaRef.Subst(Info->getTemplateArgs(), Info->getNumTemplateArgs(),
ExplicitArgs, TemplateArgs))
return nullptr;
if (SemaRef.CheckFunctionTemplateSpecialization(Method,
&ExplicitArgs,
Previous))
Method->setInvalidDecl();
IsExplicitSpecialization = true;
} else if (ClassScopeSpecializationArgs) {
// Class-scope explicit specialization written without explicit template
// arguments.
SemaRef.LookupQualifiedName(Previous, DC);
if (SemaRef.CheckFunctionTemplateSpecialization(Method, nullptr, Previous))
Method->setInvalidDecl();
IsExplicitSpecialization = true;
} else if (!FunctionTemplate || TemplateParams || isFriend) {
SemaRef.LookupQualifiedName(Previous, Record);
// In C++, the previous declaration we find might be a tag type
// (class or enum). In this case, the new declaration will hide the
// tag type. Note that this does does not apply if we're declaring a
// typedef (C++ [dcl.typedef]p4).
if (Previous.isSingleTagDecl())
Previous.clear();
}
SemaRef.CheckFunctionDeclaration(nullptr, Method, Previous,
IsExplicitSpecialization);
if (D->isPure())
SemaRef.CheckPureMethod(Method, SourceRange());
// Propagate access. For a non-friend declaration, the access is
// whatever we're propagating from. For a friend, it should be the
// previous declaration we just found.
if (isFriend && Method->getPreviousDecl())
Method->setAccess(Method->getPreviousDecl()->getAccess());
else
Method->setAccess(D->getAccess());
if (FunctionTemplate)
FunctionTemplate->setAccess(Method->getAccess());
SemaRef.CheckOverrideControl(Method);
// If a function is defined as defaulted or deleted, mark it as such now.
if (D->isExplicitlyDefaulted())
SemaRef.SetDeclDefaulted(Method, Method->getLocation());
if (D->isDeletedAsWritten())
SemaRef.SetDeclDeleted(Method, Method->getLocation());
// If this is an explicit specialization, mark the implicitly-instantiated
// template specialization as being an explicit specialization too.
// FIXME: Is this necessary?
if (IsExplicitSpecialization && !isFriend)
SemaRef.CompleteMemberSpecialization(Method, Previous);
// If there's a function template, let our caller handle it.
if (FunctionTemplate) {
// do nothing
// Don't hide a (potentially) valid declaration with an invalid one.
} else if (Method->isInvalidDecl() && !Previous.empty()) {
// do nothing
// Otherwise, check access to friends and make them visible.
} else if (isFriend) {
// We only need to re-check access for methods which we didn't
// manage to match during parsing.
if (!D->getPreviousDecl())
SemaRef.CheckFriendAccess(Method);
Record->makeDeclVisibleInContext(Method);
// Otherwise, add the declaration. We don't need to do this for
// class-scope specializations because we'll have matched them with
// the appropriate template.
} else {
Owner->addDecl(Method);
}
// PR17480: Honor the used attribute to instantiate member function
// definitions
if (Method->hasAttr<UsedAttr>()) {
if (const auto *A = dyn_cast<CXXRecordDecl>(Owner)) {
SourceLocation Loc;
if (const MemberSpecializationInfo *MSInfo =
A->getMemberSpecializationInfo())
Loc = MSInfo->getPointOfInstantiation();
else if (const auto *Spec = dyn_cast<ClassTemplateSpecializationDecl>(A))
Loc = Spec->getPointOfInstantiation();
SemaRef.MarkFunctionReferenced(Loc, Method);
}
}
return Method;
}
Decl *TemplateDeclInstantiator::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
return VisitCXXMethodDecl(D);
}
Decl *TemplateDeclInstantiator::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
return VisitCXXMethodDecl(D);
}
Decl *TemplateDeclInstantiator::VisitCXXConversionDecl(CXXConversionDecl *D) {
return VisitCXXMethodDecl(D);
}
Decl *TemplateDeclInstantiator::VisitParmVarDecl(ParmVarDecl *D) {
return SemaRef.SubstParmVarDecl(D, TemplateArgs, /*indexAdjustment*/ 0, None,
/*ExpectParameterPack=*/ false);
}
Decl *TemplateDeclInstantiator::VisitTemplateTypeParmDecl(
TemplateTypeParmDecl *D) {
// TODO: don't always clone when decls are refcounted.
assert(D->getTypeForDecl()->isTemplateTypeParmType());
TemplateTypeParmDecl *Inst = TemplateTypeParmDecl::Create(
SemaRef.Context, Owner, D->getBeginLoc(), D->getLocation(),
D->getDepth() - TemplateArgs.getNumSubstitutedLevels(), D->getIndex(),
D->getIdentifier(), D->wasDeclaredWithTypename(), D->isParameterPack());
Inst->setAccess(AS_public);
Inst->setImplicit(D->isImplicit());
if (D->hasDefaultArgument() && !D->defaultArgumentWasInherited()) {
TypeSourceInfo *InstantiatedDefaultArg =
SemaRef.SubstType(D->getDefaultArgumentInfo(), TemplateArgs,
D->getDefaultArgumentLoc(), D->getDeclName());
if (InstantiatedDefaultArg)
Inst->setDefaultArgument(InstantiatedDefaultArg);
}
// Introduce this template parameter's instantiation into the instantiation
// scope.
SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Inst);
return Inst;
}
Decl *TemplateDeclInstantiator::VisitNonTypeTemplateParmDecl(
NonTypeTemplateParmDecl *D) {
// Substitute into the type of the non-type template parameter.
TypeLoc TL = D->getTypeSourceInfo()->getTypeLoc();
SmallVector<TypeSourceInfo *, 4> ExpandedParameterPackTypesAsWritten;
SmallVector<QualType, 4> ExpandedParameterPackTypes;
bool IsExpandedParameterPack = false;
TypeSourceInfo *DI;
QualType T;
bool Invalid = false;
if (D->isExpandedParameterPack()) {
// The non-type template parameter pack is an already-expanded pack
// expansion of types. Substitute into each of the expanded types.
ExpandedParameterPackTypes.reserve(D->getNumExpansionTypes());
ExpandedParameterPackTypesAsWritten.reserve(D->getNumExpansionTypes());
for (unsigned I = 0, N = D->getNumExpansionTypes(); I != N; ++I) {
TypeSourceInfo *NewDI =
SemaRef.SubstType(D->getExpansionTypeSourceInfo(I), TemplateArgs,
D->getLocation(), D->getDeclName());
if (!NewDI)
return nullptr;
QualType NewT =
SemaRef.CheckNonTypeTemplateParameterType(NewDI, D->getLocation());
if (NewT.isNull())
return nullptr;
ExpandedParameterPackTypesAsWritten.push_back(NewDI);
ExpandedParameterPackTypes.push_back(NewT);
}
IsExpandedParameterPack = true;
DI = D->getTypeSourceInfo();
T = DI->getType();
} else if (D->isPackExpansion()) {
// The non-type template parameter pack's type is a pack expansion of types.
// Determine whether we need to expand this parameter pack into separate
// types.
PackExpansionTypeLoc Expansion = TL.castAs<PackExpansionTypeLoc>();
TypeLoc Pattern = Expansion.getPatternLoc();
SmallVector<UnexpandedParameterPack, 2> Unexpanded;
SemaRef.collectUnexpandedParameterPacks(Pattern, Unexpanded);
// Determine whether the set of unexpanded parameter packs can and should
// be expanded.
bool Expand = true;
bool RetainExpansion = false;
Optional<unsigned> OrigNumExpansions
= Expansion.getTypePtr()->getNumExpansions();
Optional<unsigned> NumExpansions = OrigNumExpansions;
if (SemaRef.CheckParameterPacksForExpansion(Expansion.getEllipsisLoc(),
Pattern.getSourceRange(),
Unexpanded,
TemplateArgs,
Expand, RetainExpansion,
NumExpansions))
return nullptr;
if (Expand) {
for (unsigned I = 0; I != *NumExpansions; ++I) {
Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, I);
TypeSourceInfo *NewDI = SemaRef.SubstType(Pattern, TemplateArgs,
D->getLocation(),
D->getDeclName());
if (!NewDI)
return nullptr;
QualType NewT =
SemaRef.CheckNonTypeTemplateParameterType(NewDI, D->getLocation());
if (NewT.isNull())
return nullptr;
ExpandedParameterPackTypesAsWritten.push_back(NewDI);
ExpandedParameterPackTypes.push_back(NewT);
}
// Note that we have an expanded parameter pack. The "type" of this
// expanded parameter pack is the original expansion type, but callers
// will end up using the expanded parameter pack types for type-checking.
IsExpandedParameterPack = true;
DI = D->getTypeSourceInfo();
T = DI->getType();
} else {
// We cannot fully expand the pack expansion now, so substitute into the
// pattern and create a new pack expansion type.
Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, -1);
TypeSourceInfo *NewPattern = SemaRef.SubstType(Pattern, TemplateArgs,
D->getLocation(),
D->getDeclName());
if (!NewPattern)
return nullptr;
SemaRef.CheckNonTypeTemplateParameterType(NewPattern, D->getLocation());
DI = SemaRef.CheckPackExpansion(NewPattern, Expansion.getEllipsisLoc(),
NumExpansions);
if (!DI)
return nullptr;
T = DI->getType();
}
} else {
// Simple case: substitution into a parameter that is not a parameter pack.
DI = SemaRef.SubstType(D->getTypeSourceInfo(), TemplateArgs,
D->getLocation(), D->getDeclName());
if (!DI)
return nullptr;
// Check that this type is acceptable for a non-type template parameter.
T = SemaRef.CheckNonTypeTemplateParameterType(DI, D->getLocation());
if (T.isNull()) {
T = SemaRef.Context.IntTy;
Invalid = true;
}
}
NonTypeTemplateParmDecl *Param;
if (IsExpandedParameterPack)
Param = NonTypeTemplateParmDecl::Create(
SemaRef.Context, Owner, D->getInnerLocStart(), D->getLocation(),
D->getDepth() - TemplateArgs.getNumSubstitutedLevels(),
D->getPosition(), D->getIdentifier(), T, DI, ExpandedParameterPackTypes,
ExpandedParameterPackTypesAsWritten);
else
Param = NonTypeTemplateParmDecl::Create(
SemaRef.Context, Owner, D->getInnerLocStart(), D->getLocation(),
D->getDepth() - TemplateArgs.getNumSubstitutedLevels(),
D->getPosition(), D->getIdentifier(), T, D->isParameterPack(), DI);
Param->setAccess(AS_public);
Param->setImplicit(D->isImplicit());
if (Invalid)
Param->setInvalidDecl();
if (D->hasDefaultArgument() && !D->defaultArgumentWasInherited()) {
EnterExpressionEvaluationContext ConstantEvaluated(
SemaRef, Sema::ExpressionEvaluationContext::ConstantEvaluated);
ExprResult Value = SemaRef.SubstExpr(D->getDefaultArgument(), TemplateArgs);
if (!Value.isInvalid())
Param->setDefaultArgument(Value.get());
}
// Introduce this template parameter's instantiation into the instantiation
// scope.
SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
return Param;
}
static void collectUnexpandedParameterPacks(
Sema &S,
TemplateParameterList *Params,
SmallVectorImpl<UnexpandedParameterPack> &Unexpanded) {
for (const auto &P : *Params) {
if (P->isTemplateParameterPack())
continue;
if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(P))
S.collectUnexpandedParameterPacks(NTTP->getTypeSourceInfo()->getTypeLoc(),
Unexpanded);
if (TemplateTemplateParmDecl *TTP = dyn_cast<TemplateTemplateParmDecl>(P))
collectUnexpandedParameterPacks(S, TTP->getTemplateParameters(),
Unexpanded);
}
}
Decl *
TemplateDeclInstantiator::VisitTemplateTemplateParmDecl(
TemplateTemplateParmDecl *D) {
// Instantiate the template parameter list of the template template parameter.
TemplateParameterList *TempParams = D->getTemplateParameters();
TemplateParameterList *InstParams;
SmallVector<TemplateParameterList*, 8> ExpandedParams;
bool IsExpandedParameterPack = false;
if (D->isExpandedParameterPack()) {
// The template template parameter pack is an already-expanded pack
// expansion of template parameters. Substitute into each of the expanded
// parameters.
ExpandedParams.reserve(D->getNumExpansionTemplateParameters());
for (unsigned I = 0, N = D->getNumExpansionTemplateParameters();
I != N; ++I) {
LocalInstantiationScope Scope(SemaRef);
TemplateParameterList *Expansion =
SubstTemplateParams(D->getExpansionTemplateParameters(I));
if (!Expansion)
return nullptr;
ExpandedParams.push_back(Expansion);
}
IsExpandedParameterPack = true;
InstParams = TempParams;
} else if (D->isPackExpansion()) {
// The template template parameter pack expands to a pack of template
// template parameters. Determine whether we need to expand this parameter
// pack into separate parameters.
SmallVector<UnexpandedParameterPack, 2> Unexpanded;
collectUnexpandedParameterPacks(SemaRef, D->getTemplateParameters(),
Unexpanded);
// Determine whether the set of unexpanded parameter packs can and should
// be expanded.
bool Expand = true;
bool RetainExpansion = false;
Optional<unsigned> NumExpansions;
if (SemaRef.CheckParameterPacksForExpansion(D->getLocation(),
TempParams->getSourceRange(),
Unexpanded,
TemplateArgs,
Expand, RetainExpansion,
NumExpansions))
return nullptr;
if (Expand) {
for (unsigned I = 0; I != *NumExpansions; ++I) {
Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, I);
LocalInstantiationScope Scope(SemaRef);
TemplateParameterList *Expansion = SubstTemplateParams(TempParams);
if (!Expansion)
return nullptr;
ExpandedParams.push_back(Expansion);
}
// Note that we have an expanded parameter pack. The "type" of this
// expanded parameter pack is the original expansion type, but callers
// will end up using the expanded parameter pack types for type-checking.
IsExpandedParameterPack = true;
InstParams = TempParams;
} else {
// We cannot fully expand the pack expansion now, so just substitute
// into the pattern.
Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, -1);
LocalInstantiationScope Scope(SemaRef);
InstParams = SubstTemplateParams(TempParams);
if (!InstParams)
return nullptr;
}
} else {
// Perform the actual substitution of template parameters within a new,
// local instantiation scope.
LocalInstantiationScope Scope(SemaRef);
InstParams = SubstTemplateParams(TempParams);
if (!InstParams)
return nullptr;
}
// Build the template template parameter.
TemplateTemplateParmDecl *Param;
if (IsExpandedParameterPack)
Param = TemplateTemplateParmDecl::Create(
SemaRef.Context, Owner, D->getLocation(),
D->getDepth() - TemplateArgs.getNumSubstitutedLevels(),
D->getPosition(), D->getIdentifier(), InstParams, ExpandedParams);
else
Param = TemplateTemplateParmDecl::Create(
SemaRef.Context, Owner, D->getLocation(),
D->getDepth() - TemplateArgs.getNumSubstitutedLevels(),
D->getPosition(), D->isParameterPack(), D->getIdentifier(), InstParams);
if (D->hasDefaultArgument() && !D->defaultArgumentWasInherited()) {
NestedNameSpecifierLoc QualifierLoc =
D->getDefaultArgument().getTemplateQualifierLoc();
QualifierLoc =
SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc, TemplateArgs);
TemplateName TName = SemaRef.SubstTemplateName(
QualifierLoc, D->getDefaultArgument().getArgument().getAsTemplate(),
D->getDefaultArgument().getTemplateNameLoc(), TemplateArgs);