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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 "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/AST/TypeVisitor.h"
#include "clang/Basic/LangOptions.h"
#include "clang/Basic/Stack.h"
#include "clang/Basic/TargetInfo.h"
#include "clang/Sema/DeclSpec.h"
#include "clang/Sema/Initialization.h"
#include "clang/Sema/Lookup.h"
#include "clang/Sema/SemaConcept.h"
#include "clang/Sema/SemaInternal.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 (!RelativeToPrimary && Function->getTemplateSpecializationKind() ==
TSK_ExplicitSpecialization) {
// This is an implicit instantiation of an explicit specialization. We
// don't get any template arguments from this function but might get
// some from an enclosing template.
} else 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 (isGenericLambdaCallOperatorOrStaticInvokerSpecialization(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:
case ConstraintsCheck:
case NestedRequirementConstraintsCheck:
return true;
case RequirementInstantiation:
case DefaultTemplateArgumentChecking:
case DeclaringSpecialMember:
case DeclaringImplicitEqualityComparison:
case DefiningSynthesizedFunction:
case ExceptionSpecEvaluation:
case ConstraintSubstitution:
case ParameterMappingSubstitution:
case ConstraintNormalization:
case RewritingOperatorAsSpaceship:
case InitializingStructuredBinding:
case MarkingClassDllexported:
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.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 = !Inst.Entity ? false :
!SemaRef.InstantiatingSpecializations
.insert({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) {}
Sema::InstantiatingTemplate::InstantiatingTemplate(
Sema &SemaRef, SourceLocation PointOfInstantiation,
concepts::Requirement *Req, sema::TemplateDeductionInfo &DeductionInfo,
SourceRange InstantiationRange)
: InstantiatingTemplate(
SemaRef, CodeSynthesisContext::RequirementInstantiation,
PointOfInstantiation, InstantiationRange, /*Entity=*/nullptr,
/*Template=*/nullptr, /*TemplateArgs=*/None, &DeductionInfo) {}
Sema::InstantiatingTemplate::InstantiatingTemplate(
Sema &SemaRef, SourceLocation PointOfInstantiation,
concepts::NestedRequirement *Req, ConstraintsCheck,
SourceRange InstantiationRange)
: InstantiatingTemplate(
SemaRef, CodeSynthesisContext::NestedRequirementConstraintsCheck,
PointOfInstantiation, InstantiationRange, /*Entity=*/nullptr,
/*Template=*/nullptr, /*TemplateArgs=*/None) {}
Sema::InstantiatingTemplate::InstantiatingTemplate(
Sema &SemaRef, SourceLocation PointOfInstantiation,
ConstraintsCheck, NamedDecl *Template,
ArrayRef<TemplateArgument> TemplateArgs, SourceRange InstantiationRange)
: InstantiatingTemplate(
SemaRef, CodeSynthesisContext::ConstraintsCheck,
PointOfInstantiation, InstantiationRange, Template, nullptr,
TemplateArgs) {}
Sema::InstantiatingTemplate::InstantiatingTemplate(
Sema &SemaRef, SourceLocation PointOfInstantiation,
ConstraintSubstitution, NamedDecl *Template,
sema::TemplateDeductionInfo &DeductionInfo, SourceRange InstantiationRange)
: InstantiatingTemplate(
SemaRef, CodeSynthesisContext::ConstraintSubstitution,
PointOfInstantiation, InstantiationRange, Template, nullptr,
{}, &DeductionInfo) {}
Sema::InstantiatingTemplate::InstantiatingTemplate(
Sema &SemaRef, SourceLocation PointOfInstantiation,
ConstraintNormalization, NamedDecl *Template,
SourceRange InstantiationRange)
: InstantiatingTemplate(
SemaRef, CodeSynthesisContext::ConstraintNormalization,
PointOfInstantiation, InstantiationRange, Template) {}
Sema::InstantiatingTemplate::InstantiatingTemplate(
Sema &SemaRef, SourceLocation PointOfInstantiation,
ParameterMappingSubstitution, NamedDecl *Template,
SourceRange InstantiationRange)
: InstantiatingTemplate(
SemaRef, CodeSynthesisContext::ParameterMappingSubstitution,
PointOfInstantiation, InstantiationRange, Template) {}
void Sema::pushCodeSynthesisContext(CodeSynthesisContext Ctx) {
Ctx.SavedInNonInstantiationSFINAEContext = InNonInstantiationSFINAEContext;
InNonInstantiationSFINAEContext = false;
CodeSynthesisContexts.push_back(Ctx);
if (!Ctx.isInstantiationRecord())
++NonInstantiationEntries;
// Check to see if we're low on stack space. We can't do anything about this
// from here, but we can at least warn the user.
if (isStackNearlyExhausted())
warnStackExhausted(Ctx.PointOfInstantiation);
}
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();
if (Active.Entity)
SemaRef.InstantiatingSpecializations.erase(
{Active.Entity->getCanonicalDecl(), 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);
SmallString<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());
SmallString<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::RequirementInstantiation:
Diags.Report(Active->PointOfInstantiation,
diag::note_template_requirement_instantiation_here)
<< Active->InstantiationRange;
break;
case CodeSynthesisContext::NestedRequirementConstraintsCheck:
Diags.Report(Active->PointOfInstantiation,
diag::note_nested_requirement_here)
<< 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::DeclaringImplicitEqualityComparison:
Diags.Report(Active->Entity->getLocation(),
diag::note_in_declaration_of_implicit_equality_comparison);
break;
case CodeSynthesisContext::DefiningSynthesizedFunction: {
// FIXME: For synthesized functions that are not defaulted,
// produce a note.
auto *FD = dyn_cast<FunctionDecl>(Active->Entity);
DefaultedFunctionKind DFK =
FD ? getDefaultedFunctionKind(FD) : DefaultedFunctionKind();
if (DFK.isSpecialMember()) {
auto *MD = cast<CXXMethodDecl>(FD);
Diags.Report(Active->PointOfInstantiation,
diag::note_member_synthesized_at)
<< MD->isExplicitlyDefaulted() << DFK.asSpecialMember()
<< Context.getTagDeclType(MD->getParent());
} else if (DFK.isComparison()) {
Diags.Report(Active->PointOfInstantiation,
diag::note_comparison_synthesized_at)
<< (int)DFK.asComparison()
<< Context.getTagDeclType(
cast<CXXRecordDecl>(FD->getLexicalDeclContext()));
}
break;
}
case CodeSynthesisContext::RewritingOperatorAsSpaceship:
Diags.Report(Active->Entity->getLocation(),
diag::note_rewriting_operator_as_spaceship);
break;
case CodeSynthesisContext::InitializingStructuredBinding:
Diags.Report(Active->PointOfInstantiation,
diag::note_in_binding_decl_init)
<< cast<BindingDecl>(Active->Entity);
break;
case CodeSynthesisContext::MarkingClassDllexported:
Diags.Report(Active->PointOfInstantiation,
diag::note_due_to_dllexported_class)
<< cast<CXXRecordDecl>(Active->Entity) << !getLangOpts().CPlusPlus11;
break;
case CodeSynthesisContext::Memoization:
break;
case CodeSynthesisContext::ConstraintsCheck: {
unsigned DiagID = 0;
if (!Active->Entity) {
Diags.Report(Active->PointOfInstantiation,
diag::note_nested_requirement_here)
<< Active->InstantiationRange;
break;
}
if (isa<ConceptDecl>(Active->Entity))
DiagID = diag::note_concept_specialization_here;
else if (isa<TemplateDecl>(Active->Entity))
DiagID = diag::note_checking_constraints_for_template_id_here;
else if (isa<VarTemplatePartialSpecializationDecl>(Active->Entity))
DiagID = diag::note_checking_constraints_for_var_spec_id_here;
else if (isa<ClassTemplatePartialSpecializationDecl>(Active->Entity))
DiagID = diag::note_checking_constraints_for_class_spec_id_here;
else {
assert(isa<FunctionDecl>(Active->Entity));
DiagID = diag::note_checking_constraints_for_function_here;
}
SmallString<128> TemplateArgsStr;
llvm::raw_svector_ostream OS(TemplateArgsStr);
cast<NamedDecl>(Active->Entity)->printName(OS);
if (!isa<FunctionDecl>(Active->Entity))
printTemplateArgumentList(OS, Active->template_arguments(),
getPrintingPolicy());
Diags.Report(Active->PointOfInstantiation, DiagID) << OS.str()
<< Active->InstantiationRange;
break;
}
case CodeSynthesisContext::ConstraintSubstitution:
Diags.Report(Active->PointOfInstantiation,
diag::note_constraint_substitution_here)
<< Active->InstantiationRange;
break;
case CodeSynthesisContext::ConstraintNormalization:
Diags.Report(Active->PointOfInstantiation,
diag::note_constraint_normalization_here)
<< cast<NamedDecl>(Active->Entity)->getName()
<< Active->InstantiationRange;
break;
case CodeSynthesisContext::ParameterMappingSubstitution:
Diags.Report(Active->PointOfInstantiation,
diag::note_parameter_mapping_substitution_here)
<< Active->InstantiationRange;
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:
case CodeSynthesisContext::ConstraintsCheck:
case CodeSynthesisContext::ParameterMappingSubstitution:
case CodeSynthesisContext::ConstraintNormalization:
case CodeSynthesisContext::NestedRequirementConstraintsCheck:
// This is a template instantiation, so there is no SFINAE.
return None;
case CodeSynthesisContext::DefaultTemplateArgumentInstantiation:
case CodeSynthesisContext::PriorTemplateArgumentSubstitution:
case CodeSynthesisContext::DefaultTemplateArgumentChecking:
case CodeSynthesisContext::RewritingOperatorAsSpaceship:
// 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:
case CodeSynthesisContext::ConstraintSubstitution:
case CodeSynthesisContext::RequirementInstantiation:
// We're either substituting explicitly-specified template arguments,
// deduced template arguments, a constraint expression or a requirement
// in a requires expression, so SFINAE applies.
assert(Active->DeductionInfo && "Missing deduction info pointer");
return Active->DeductionInfo;
case CodeSynthesisContext::DeclaringSpecialMember:
case CodeSynthesisContext::DeclaringImplicitEqualityComparison:
case CodeSynthesisContext::DefiningSynthesizedFunction:
case CodeSynthesisContext::InitializingStructuredBinding:
case CodeSynthesisContext::MarkingClassDllexported:
// 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;
}
unsigned TransformTemplateDepth(unsigned Depth) {
return TemplateArgs.getNewDepth(Depth);
}
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, ArrayRef<Decl *> NewDecls) {
if (Old->isParameterPack()) {
SemaRef.CurrentInstantiationScope->MakeInstantiatedLocalArgPack(Old);
for (auto *New : NewDecls)
SemaRef.CurrentInstantiationScope->InstantiatedLocalPackArg(
Old, cast<VarDecl>(New));
return;
}
assert(NewDecls.size() == 1 &&
"should only have multiple expansions for a pack");
Decl *New = NewDecls.front();
// 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);
ExprResult TransformSubstNonTypeTemplateParmExpr(
SubstNonTypeTemplateParmExpr *E);
/// Rebuild a DeclRefExpr for a VarDecl reference.
ExprResult RebuildVarDeclRefExpr(VarDecl *PD, SourceLocation Loc);
/// Transform a reference to a function or init-capture parameter pack.
ExprResult TransformFunctionParmPackRefExpr(DeclRefExpr *E, VarDecl *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);
}
ExprResult TransformRequiresExpr(RequiresExpr *E) {
LocalInstantiationScope Scope(SemaRef, /*CombineWithOuterScope=*/true);
return TreeTransform<TemplateInstantiator>::TransformRequiresExpr(E);
}
bool TransformRequiresExprRequirements(
ArrayRef<concepts::Requirement *> Reqs,
SmallVectorImpl<concepts::Requirement *> &Transformed) {
bool SatisfactionDetermined = false;
for (concepts::Requirement *Req : Reqs) {
concepts::Requirement *TransReq = nullptr;
if (!SatisfactionDetermined) {
if (auto *TypeReq = dyn_cast<concepts::TypeRequirement>(Req))
TransReq = TransformTypeRequirement(TypeReq);
else if (auto *ExprReq = dyn_cast<concepts::ExprRequirement>(Req))
TransReq = TransformExprRequirement(ExprReq);
else
TransReq = TransformNestedRequirement(
cast<concepts::NestedRequirement>(Req));
if (!TransReq)
return true;
if (!TransReq->isDependent() && !TransReq->isSatisfied())
// [expr.prim.req]p6
// [...] The substitution and semantic constraint checking
// proceeds in lexical order and stops when a condition that
// determines the result of the requires-expression is
// encountered. [..]
SatisfactionDetermined = true;
} else
TransReq = Req;
Transformed.push_back(TransReq);
}
return false;
}
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);
}
concepts::TypeRequirement *
TransformTypeRequirement(concepts::TypeRequirement *Req);
concepts::ExprRequirement *
TransformExprRequirement(concepts::ExprRequirement *Req);
concepts::NestedRequirement *
TransformNestedRequirement(concepts::NestedRequirement *Req);
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 (TemplateArgs.isRewrite()) {
// We're rewriting the template parameter as a reference to another
// template parameter.
if (Arg.getKind() == TemplateArgument::Pack) {
assert(Arg.pack_size() == 1 && Arg.pack_begin()->isPackExpansion() &&
"unexpected pack arguments in template rewrite");
Arg = Arg.pack_begin()->getPackExpansionPattern();
}
assert(Arg.getKind() == TemplateArgument::Template &&
"unexpected nontype template argument kind in template rewrite");
return Arg.getAsTemplate();
}
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.isRewrite()) {
// We're rewriting the template parameter as a reference to another
// template parameter.
if (Arg.getKind() == TemplateArgument::Pack) {
assert(Arg.pack_size() == 1 && Arg.pack_begin()->isPackExpansion() &&
"unexpected pack arguments in template rewrite");
Arg = Arg.pack_begin()->getPackExpansionPattern();
}
assert(Arg.getKind() == TemplateArgument::Expression &&
"unexpected nontype template argument kind in template rewrite");
// FIXME: This can lead to the same subexpression appearing multiple times
// in a complete expression.
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();
QualType ExprType = TargetType.getNonLValueExprType(SemaRef.Context);
if (TargetType->isRecordType())
ExprType.addConst();
return new (SemaRef.Context) SubstNonTypeTemplateParmPackExpr(
ExprType, 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->getOption(),
LH->getState(), TransformedExpr, *LH);
}
ExprResult TemplateInstantiator::transformNonTypeTemplateParmRef(
NonTypeTemplateParmDecl *parm,
SourceLocation loc,
TemplateArgument arg) {
ExprResult result;
// Determine the substituted parameter type. We can usually infer this from
// the template argument, but not always.
auto SubstParamType = [&] {
QualType T;
if (parm->isExpandedParameterPack())
T = parm->getExpansionType(SemaRef.ArgumentPackSubstitutionIndex);
else
T = parm->getType();
if (parm->isParameterPack() && isa<PackExpansionType>(T))
T = cast<PackExpansionType>(T)->getPattern();
return SemaRef.SubstType(T, TemplateArgs, loc, parm->getDeclName());
};
bool refParam = false;
// The template argument itself might be an expression, in which case we just
// return that expression. This happens when substituting into an alias
// template.
if (arg.getKind() == TemplateArgument::Expression) {
Expr *argExpr = arg.getAsExpr();
result = argExpr;
if (argExpr->isLValue()) {
if (argExpr->getType()->isRecordType()) {
// Check whether the parameter was actually a reference.
QualType paramType = SubstParamType();
if (paramType.isNull())
return ExprError();
refParam = paramType->isReferenceType();
} else {
refParam = true;
}
}
} 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;
}
QualType paramType = VD ? arg.getParamTypeForDecl() : arg.getNullPtrType();
assert(!paramType.isNull() && "type substitution failed for param type");
assert(!paramType->isDependentType() && "param type still dependent");
result = SemaRef.BuildExpressionFromDeclTemplateArgument(arg, paramType, loc);
refParam = paramType->isReferenceType();
} else {
result = SemaRef.BuildExpressionFromIntegralTemplateArgument(arg, loc);
assert(result.isInvalid() ||
SemaRef.Context.hasSameType(result.get()->getType(),
arg.getIntegralType()));
}
if (result.isInvalid())
return ExprError();
Expr *resultExpr = result.get();
return new (SemaRef.Context) SubstNonTypeTemplateParmExpr(
resultExpr->getType(), resultExpr->getValueKind(), loc, parm, refParam,
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::TransformSubstNonTypeTemplateParmExpr(
SubstNonTypeTemplateParmExpr *E) {
ExprResult SubstReplacement = E->getReplacement();
if (!isa<ConstantExpr>(SubstReplacement.get()))
SubstReplacement = TransformExpr(E->getReplacement());
if (SubstReplacement.isInvalid())
return true;
QualType SubstType = TransformType(E->getParameterType(getSema().Context));
if (SubstType.isNull())
return true;
// The type may have been previously dependent and not now, which means we
// might have to implicit cast the argument to the new type, for example:
// template<auto T, decltype(T) U>
// concept C = sizeof(U) == 4;
// void foo() requires C<2, 'a'> { }
// When normalizing foo(), we first form the normalized constraints of C:
// AtomicExpr(sizeof(U) == 4,
// U=SubstNonTypeTemplateParmExpr(Param=U,
// Expr=DeclRef(U),
// Type=decltype(T)))
// Then we substitute T = 2, U = 'a' into the parameter mapping, and need to
// produce:
// AtomicExpr(sizeof(U) == 4,
// U=SubstNonTypeTemplateParmExpr(Param=U,
// Expr=ImpCast(
// decltype(2),
// SubstNTTPE(Param=U, Expr='a',
// Type=char)),
// Type=decltype(2)))
// The call to CheckTemplateArgument here produces the ImpCast.
TemplateArgument Converted;
if (SemaRef.CheckTemplateArgument(E->getParameter(), SubstType,
SubstReplacement.get(),
Converted).isInvalid())
return true;
return transformNonTypeTemplateParmRef(E->getParameter(),
E->getExprLoc(), Converted);
}
ExprResult TemplateInstantiator::RebuildVarDeclRefExpr(VarDecl *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.
VarDecl *D = E->getExpansion(getSema().ArgumentPackSubstitutionIndex);
VarDecl *VD = cast_or_null<VarDecl>(TransformDecl(E->getExprLoc(), D));
if (!VD)
return ExprError();
return RebuildVarDeclRefExpr(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<VarDecl *, 8> Vars;
Vars.reserve(E->getNumExpansions());
for (FunctionParmPackExpr::iterator I = E->begin(), End = E->end();
I != End; ++I) {
VarDecl *D = cast_or_null<VarDecl>(TransformDecl(E->getExprLoc(), *I));
if (!D)
return ExprError();
Vars.push_back(D);
}
auto *PackExpr =
FunctionParmPackExpr::Create(getSema().Context, T, E->getParameterPack(),
E->getParameterPackLocation(), Vars);
getSema().MarkFunctionParmPackReferenced(PackExpr);
return PackExpr;
}
ExprResult
TemplateInstantiator::TransformFunctionParmPackRefExpr(DeclRefExpr *E,
VarDecl *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();
auto *PackExpr = FunctionParmPackExpr::Create(getSema().Context, T, PD,
E->getExprLoc(), *Pack);
getSema().MarkFunctionParmPackReferenced(PackExpr);
return PackExpr;
}
TransformedDecl = (*Pack)[getSema().ArgumentPackSubstitutionIndex];
} else {
TransformedDecl = Found->get<Decl*>();
}
// We have either an unexpanded pack or a specific expansion.
return RebuildVarDeclRefExpr(cast<VarDecl>(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 (VarDecl *PD = dyn_cast<VarDecl>(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) {
auto NewParm =
SemaRef.SubstParmVarDecl(OldParm, TemplateArgs, indexAdjustment,
NumExpansions, ExpectParameterPack);
if (NewParm && SemaRef.getLangOpts().OpenCL)
SemaRef.deduceOpenCLAddressSpace(NewParm);
return NewParm;
}
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 (TemplateArgs.isRewrite()) {
// We're rewriting the template parameter as a reference to another
// template parameter.
if (Arg.getKind() == TemplateArgument::Pack) {
assert(Arg.pack_size() == 1 && Arg.pack_begin()->isPackExpansion() &&
"unexpected pack arguments in template rewrite");
Arg = Arg.pack_begin()->getPackExpansionPattern();
}
assert(Arg.getKind() == TemplateArgument::Type &&
"unexpected nontype template argument kind in template rewrite");
QualType NewT = Arg.getAsType();
assert(isa<TemplateTypeParmType>(NewT) &&
"type parm not rewritten to type parm");
auto NewTL = TLB.push<TemplateTypeParmTypeLoc>(NewT);
NewTL.setNameLoc(TL.getNameLoc());
return NewT;
}
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;
}
template<typename EntityPrinter>
static concepts::Requirement::SubstitutionDiagnostic *
createSubstDiag(Sema &S, TemplateDeductionInfo &Info, EntityPrinter Printer) {
SmallString<128> Message;
SourceLocation ErrorLoc;
if (Info.hasSFINAEDiagnostic()) {
PartialDiagnosticAt PDA(SourceLocation(),
PartialDiagnostic::NullDiagnostic{});
Info.takeSFINAEDiagnostic(PDA);
PDA.second.EmitToString(S.getDiagnostics(), Message);
ErrorLoc = PDA.first;
} else {
ErrorLoc = Info.getLocation();
}
char *MessageBuf = new (S.Context) char[Message.size()];
std::copy(Message.begin(), Message.end(), MessageBuf);
SmallString<128> Entity;
llvm::raw_svector_ostream OS(Entity);
Printer(OS);
char *EntityBuf = new (S.Context) char[Entity.size()];
std::copy(Entity.begin(), Entity.end(), EntityBuf);
return new (S.Context) concepts::Requirement::SubstitutionDiagnostic{
StringRef(EntityBuf, Entity.size()), ErrorLoc,
StringRef(MessageBuf, Message.size())};
}
concepts::TypeRequirement *
TemplateInstantiator::TransformTypeRequirement(concepts::TypeRequirement *Req) {
if (!Req->isDependent() && !AlwaysRebuild())
return Req;
if (Req->isSubstitutionFailure()) {
if (AlwaysRebuild())
return RebuildTypeRequirement(
Req->getSubstitutionDiagnostic());
return Req;
}
Sema::SFINAETrap Trap(SemaRef);
TemplateDeductionInfo Info(Req->getType()->getTypeLoc().getBeginLoc());
Sema::InstantiatingTemplate TypeInst(SemaRef,
Req->getType()->getTypeLoc().getBeginLoc(), Req, Info,
Req->getType()->getTypeLoc().getSourceRange());
if (TypeInst.isInvalid())
return nullptr;
TypeSourceInfo *TransType = TransformType(Req->getType());
if (!TransType || Trap.hasErrorOccurred())
return RebuildTypeRequirement(createSubstDiag(SemaRef, Info,
[&] (llvm::raw_ostream& OS) {
Req->getType()->getType().print(OS, SemaRef.getPrintingPolicy());
}));
return RebuildTypeRequirement(TransType);
}
concepts::ExprRequirement *
TemplateInstantiator::TransformExprRequirement(concepts::ExprRequirement *Req) {
if (!Req->isDependent() && !AlwaysRebuild())
return Req;
Sema::SFINAETrap Trap(SemaRef);
TemplateDeductionInfo Info(Req->getExpr()->getBeginLoc());
llvm::PointerUnion<Expr *, concepts::Requirement::SubstitutionDiagnostic *>
TransExpr;
if (Req->isExprSubstitutionFailure())
TransExpr = Req->getExprSubstitutionDiagnostic();
else {
Sema::InstantiatingTemplate ExprInst(SemaRef, Req->getExpr()->getBeginLoc(),
Req, Info,
Req->getExpr()->getSourceRange());
if (ExprInst.isInvalid())
return nullptr;
ExprResult TransExprRes = TransformExpr(Req->getExpr());
if (TransExprRes.isInvalid() || Trap.hasErrorOccurred())
TransExpr = createSubstDiag(SemaRef, Info,
[&] (llvm::raw_ostream& OS) {
Req->getExpr()->printPretty(OS, nullptr,
SemaRef.getPrintingPolicy());
});
else
TransExpr = TransExprRes.get();
}
llvm::Optional<concepts::ExprRequirement::ReturnTypeRequirement> TransRetReq;
const auto &RetReq = Req->getReturnTypeRequirement();
if (RetReq.isEmpty())
TransRetReq.emplace();
else if (RetReq.isSubstitutionFailure())
TransRetReq.emplace(RetReq.getSubstitutionDiagnostic());
else if (RetReq.isTypeConstraint()) {
TemplateParameterList *OrigTPL =
RetReq.getTypeConstraintTemplateParameterList();
Sema::InstantiatingTemplate TPLInst(SemaRef, OrigTPL->getTemplateLoc(),
Req, Info, OrigTPL->getSourceRange());
if (TPLInst.isInvalid())
return nullptr;
TemplateParameterList *TPL =
TransformTemplateParameterList(OrigTPL);
if (!TPL)
TransRetReq.emplace(createSubstDiag(SemaRef, Info,
[&] (llvm::raw_ostream& OS) {
RetReq.getTypeConstraint()->getImmediatelyDeclaredConstraint()
->printPretty(OS, nullptr, SemaRef.getPrintingPolicy());
}));
else {
TPLInst.Clear();
TransRetReq.emplace(TPL);
}
}
assert(TransRetReq.hasValue() &&
"All code paths leading here must set TransRetReq");
if (Expr *E = TransExpr.dyn_cast<Expr *>())
return RebuildExprRequirement(E, Req->isSimple(), Req->getNoexceptLoc(),
std::move(*TransRetReq));
return RebuildExprRequirement(
TransExpr.get<concepts::Requirement::SubstitutionDiagnostic *>(),
Req->isSimple(), Req->getNoexceptLoc(), std::move(*TransRetReq));
}
concepts::NestedRequirement *
TemplateInstantiator::TransformNestedRequirement(
concepts::NestedRequirement *Req) {
if (!Req->isDependent() && !AlwaysRebuild())
return Req;
if (Req->isSubstitutionFailure()) {
if (AlwaysRebuild())
return RebuildNestedRequirement(
Req->getSubstitutionDiagnostic());
return Req;
}
Sema::InstantiatingTemplate ReqInst(SemaRef,
Req->getConstraintExpr()->getBeginLoc(), Req,
Sema::InstantiatingTemplate::ConstraintsCheck{},
Req->getConstraintExpr()->getSourceRange());
ExprResult TransConstraint;
TemplateDeductionInfo Info(Req->getConstraintExpr()->getBeginLoc());
{
EnterExpressionEvaluationContext ContextRAII(
SemaRef, Sema::ExpressionEvaluationContext::ConstantEvaluated);
Sema::SFINAETrap Trap(SemaRef);
Sema::InstantiatingTemplate ConstrInst(SemaRef,
Req->getConstraintExpr()->getBeginLoc(), Req, Info,
Req->getConstraintExpr()->getSourceRange());
if (ConstrInst.isInvalid())
return nullptr;
TransConstraint = TransformExpr(Req->getConstraintExpr());
if (TransConstraint.isInvalid() || Trap.hasErrorOccurred())
return RebuildNestedRequirement(createSubstDiag(SemaRef, Info,
[&] (llvm::raw_ostream& OS) {
Req->getConstraintExpr()->printPretty(OS, nullptr,
SemaRef.getPrintingPolicy());
}));
}
return RebuildNestedRequirement(TransConstraint.get());
}
/// 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);
}
namespace {
struct GetContainedInventedTypeParmVisitor :
public TypeVisitor<GetContainedInventedTypeParmVisitor,
TemplateTypeParmDecl *> {
using TypeVisitor<GetContainedInventedTypeParmVisitor,
TemplateTypeParmDecl *>::Visit;
TemplateTypeParmDecl *Visit(QualType T) {
if (T.isNull())
return nullptr;
return Visit(T.getTypePtr());
}
// The deduced type itself.
TemplateTypeParmDecl *VisitTemplateTypeParmType(
const TemplateTypeParmType *T) {
if (!T->getDecl() || !T->getDecl()->isImplicit())
return nullptr;
return T->getDecl();
}
// Only these types can contain 'auto' types, and subsequently be replaced
// by references to invented parameters.
TemplateTypeParmDecl *VisitElaboratedType(const ElaboratedType *T) {
return Visit(T->getNamedType());
}
TemplateTypeParmDecl *VisitPointerType(const PointerType *T) {
return Visit(T->getPointeeType());
}
TemplateTypeParmDecl *VisitBlockPointerType(const BlockPointerType *T) {
return Visit(T->getPointeeType());
}
TemplateTypeParmDecl *VisitReferenceType(const ReferenceType *T) {
return Visit(T->getPointeeTypeAsWritten());
}
TemplateTypeParmDecl *VisitMemberPointerType(const MemberPointerType *T) {
return Visit(T->getPointeeType());
}
TemplateTypeParmDecl *VisitArrayType(const ArrayType *T) {
return Visit(T->getElementType());
}
TemplateTypeParmDecl *VisitDependentSizedExtVectorType(
const DependentSizedExtVectorType *T) {
return Visit(T->getElementType());
}
TemplateTypeParmDecl *VisitVectorType(const VectorType *T) {
return Visit(T->getElementType());
}
TemplateTypeParmDecl *VisitFunctionProtoType(const FunctionProtoType *T) {
return VisitFunctionType(T);
}
TemplateTypeParmDecl *VisitFunctionType(const FunctionType *T) {
return Visit(T->getReturnType());
}
TemplateTypeParmDecl *VisitParenType(const ParenType *T) {
return Visit(T->getInnerType());
}
TemplateTypeParmDecl *VisitAttributedType(const AttributedType *T) {
return Visit(T->getModifiedType());
}
TemplateTypeParmDecl *VisitMacroQualifiedType(const MacroQualifiedType *T) {
return Visit(T->getUnderlyingType());
}
TemplateTypeParmDecl *VisitAdjustedType(const AdjustedType *T) {
return Visit(T->getOriginalType());
}
TemplateTypeParmDecl *VisitPackExpansionType(const PackExpansionType *T) {
return Visit(T->getPattern());
}
};
} // namespace
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;
}
// In abbreviated templates, TemplateTypeParmDecls with possible
// TypeConstraints are created when the parameter list is originally parsed.
// The TypeConstraints can therefore reference other functions parameters in
// the abbreviated function template, which is why we must instantiate them
// here, when the instantiated versions of those referenced parameters are in
// scope.
if (TemplateTypeParmDecl *TTP =
GetContainedInventedTypeParmVisitor().Visit(OldDI->getType())) {
if (const TypeConstraint *TC = TTP->getTypeConstraint()) {
auto *Inst = cast_or_null<TemplateTypeParmDecl>(
FindInstantiatedDecl(TTP->getLocation(), TTP, TemplateArgs));
// We will first get here when instantiating the abbreviated function
// template's described function, but we might also get here later.
// Make sure we do not instantiate the TypeConstraint more than once.
if (Inst && !Inst->getTypeConstraint()) {
// TODO: Concepts: do not instantiate the constraint (delayed constraint
// substitution)
const ASTTemplateArgumentListInfo *TemplArgInfo
= TC->getTemplateArgsAsWritten();
TemplateArgumentListInfo InstArgs;
if (TemplArgInfo) {
InstArgs.setLAngleLoc(TemplArgInfo->LAngleLoc);
InstArgs.setRAngleLoc(TemplArgInfo->RAngleLoc);
if (Subst(TemplArgInfo->getTemplateArgs(),
TemplArgInfo->NumTemplateArgs, InstArgs, TemplateArgs))
return nullptr;
}
if (AttachTypeConstraint(
TC->getNestedNameSpecifierLoc(), TC->getConceptNameInfo(),
TC->getNamedConcept(), &InstArgs, Inst,
TTP->isParameterPack()
? cast<CXXFoldExpr>(TC->getImmediatelyDeclaredConstraint())
->getEllipsisLoc()
: SourceLocation()))
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->isInLocalScopeForInstantiation()) {
// 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();
ExprResult Result =
ConvertParamDefaultArgument(NewParm, NewArg.get(), EqualLoc);
if (Result.isInvalid())
return nullptr;
SetParamDefaultArgument(NewParm, Result.getAs<Expr>(), 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.
///
/// Pro