llvm-project/clang/lib/AST/DeclBase.cpp

1553 lines
48 KiB
C++

//===--- DeclBase.cpp - Declaration AST Node Implementation ---------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the Decl and DeclContext classes.
//
//===----------------------------------------------------------------------===//
#include "clang/AST/DeclBase.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/ASTMutationListener.h"
#include "clang/AST/Attr.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/DeclContextInternals.h"
#include "clang/AST/DeclFriend.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/DeclOpenMP.h"
#include "clang/AST/DeclTemplate.h"
#include "clang/AST/DependentDiagnostic.h"
#include "clang/AST/ExternalASTSource.h"
#include "clang/AST/Stmt.h"
#include "clang/AST/StmtCXX.h"
#include "clang/AST/Type.h"
#include "clang/Basic/TargetInfo.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
using namespace clang;
//===----------------------------------------------------------------------===//
// Statistics
//===----------------------------------------------------------------------===//
#define DECL(DERIVED, BASE) static int n##DERIVED##s = 0;
#define ABSTRACT_DECL(DECL)
#include "clang/AST/DeclNodes.inc"
void Decl::updateOutOfDate(IdentifierInfo &II) const {
getASTContext().getExternalSource()->updateOutOfDateIdentifier(II);
}
void *Decl::AllocateDeserializedDecl(const ASTContext &Context,
unsigned ID,
unsigned Size) {
// Allocate an extra 8 bytes worth of storage, which ensures that the
// resulting pointer will still be 8-byte aligned.
void *Start = Context.Allocate(Size + 8);
void *Result = (char*)Start + 8;
unsigned *PrefixPtr = (unsigned *)Result - 2;
// Zero out the first 4 bytes; this is used to store the owning module ID.
PrefixPtr[0] = 0;
// Store the global declaration ID in the second 4 bytes.
PrefixPtr[1] = ID;
return Result;
}
Module *Decl::getOwningModuleSlow() const {
assert(isFromASTFile() && "Not from AST file?");
return getASTContext().getExternalSource()->getModule(getOwningModuleID());
}
const char *Decl::getDeclKindName() const {
switch (DeclKind) {
default: llvm_unreachable("Declaration not in DeclNodes.inc!");
#define DECL(DERIVED, BASE) case DERIVED: return #DERIVED;
#define ABSTRACT_DECL(DECL)
#include "clang/AST/DeclNodes.inc"
}
}
void Decl::setInvalidDecl(bool Invalid) {
InvalidDecl = Invalid;
if (Invalid && !isa<ParmVarDecl>(this)) {
// Defensive maneuver for ill-formed code: we're likely not to make it to
// a point where we set the access specifier, so default it to "public"
// to avoid triggering asserts elsewhere in the front end.
setAccess(AS_public);
}
}
const char *DeclContext::getDeclKindName() const {
switch (DeclKind) {
default: llvm_unreachable("Declaration context not in DeclNodes.inc!");
#define DECL(DERIVED, BASE) case Decl::DERIVED: return #DERIVED;
#define ABSTRACT_DECL(DECL)
#include "clang/AST/DeclNodes.inc"
}
}
bool Decl::StatisticsEnabled = false;
void Decl::EnableStatistics() {
StatisticsEnabled = true;
}
void Decl::PrintStats() {
llvm::errs() << "\n*** Decl Stats:\n";
int totalDecls = 0;
#define DECL(DERIVED, BASE) totalDecls += n##DERIVED##s;
#define ABSTRACT_DECL(DECL)
#include "clang/AST/DeclNodes.inc"
llvm::errs() << " " << totalDecls << " decls total.\n";
int totalBytes = 0;
#define DECL(DERIVED, BASE) \
if (n##DERIVED##s > 0) { \
totalBytes += (int)(n##DERIVED##s * sizeof(DERIVED##Decl)); \
llvm::errs() << " " << n##DERIVED##s << " " #DERIVED " decls, " \
<< sizeof(DERIVED##Decl) << " each (" \
<< n##DERIVED##s * sizeof(DERIVED##Decl) \
<< " bytes)\n"; \
}
#define ABSTRACT_DECL(DECL)
#include "clang/AST/DeclNodes.inc"
llvm::errs() << "Total bytes = " << totalBytes << "\n";
}
void Decl::add(Kind k) {
switch (k) {
#define DECL(DERIVED, BASE) case DERIVED: ++n##DERIVED##s; break;
#define ABSTRACT_DECL(DECL)
#include "clang/AST/DeclNodes.inc"
}
}
bool Decl::isTemplateParameterPack() const {
if (const TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(this))
return TTP->isParameterPack();
if (const NonTypeTemplateParmDecl *NTTP
= dyn_cast<NonTypeTemplateParmDecl>(this))
return NTTP->isParameterPack();
if (const TemplateTemplateParmDecl *TTP
= dyn_cast<TemplateTemplateParmDecl>(this))
return TTP->isParameterPack();
return false;
}
bool Decl::isParameterPack() const {
if (const ParmVarDecl *Parm = dyn_cast<ParmVarDecl>(this))
return Parm->isParameterPack();
return isTemplateParameterPack();
}
bool Decl::isFunctionOrFunctionTemplate() const {
if (const UsingShadowDecl *UD = dyn_cast<UsingShadowDecl>(this))
return UD->getTargetDecl()->isFunctionOrFunctionTemplate();
return isa<FunctionDecl>(this) || isa<FunctionTemplateDecl>(this);
}
bool Decl::isTemplateDecl() const {
return isa<TemplateDecl>(this);
}
const DeclContext *Decl::getParentFunctionOrMethod() const {
for (const DeclContext *DC = getDeclContext();
DC && !DC->isTranslationUnit() && !DC->isNamespace();
DC = DC->getParent())
if (DC->isFunctionOrMethod())
return DC;
return 0;
}
//===----------------------------------------------------------------------===//
// PrettyStackTraceDecl Implementation
//===----------------------------------------------------------------------===//
void PrettyStackTraceDecl::print(raw_ostream &OS) const {
SourceLocation TheLoc = Loc;
if (TheLoc.isInvalid() && TheDecl)
TheLoc = TheDecl->getLocation();
if (TheLoc.isValid()) {
TheLoc.print(OS, SM);
OS << ": ";
}
OS << Message;
if (const NamedDecl *DN = dyn_cast_or_null<NamedDecl>(TheDecl)) {
OS << " '";
DN->printQualifiedName(OS);
OS << '\'';
}
OS << '\n';
}
//===----------------------------------------------------------------------===//
// Decl Implementation
//===----------------------------------------------------------------------===//
// Out-of-line virtual method providing a home for Decl.
Decl::~Decl() { }
void Decl::setDeclContext(DeclContext *DC) {
DeclCtx = DC;
}
void Decl::setLexicalDeclContext(DeclContext *DC) {
if (DC == getLexicalDeclContext())
return;
if (isInSemaDC()) {
setDeclContextsImpl(getDeclContext(), DC, getASTContext());
} else {
getMultipleDC()->LexicalDC = DC;
}
}
void Decl::setDeclContextsImpl(DeclContext *SemaDC, DeclContext *LexicalDC,
ASTContext &Ctx) {
if (SemaDC == LexicalDC) {
DeclCtx = SemaDC;
} else {
Decl::MultipleDC *MDC = new (Ctx) Decl::MultipleDC();
MDC->SemanticDC = SemaDC;
MDC->LexicalDC = LexicalDC;
DeclCtx = MDC;
}
}
bool Decl::isInAnonymousNamespace() const {
const DeclContext *DC = getDeclContext();
do {
if (const NamespaceDecl *ND = dyn_cast<NamespaceDecl>(DC))
if (ND->isAnonymousNamespace())
return true;
} while ((DC = DC->getParent()));
return false;
}
TranslationUnitDecl *Decl::getTranslationUnitDecl() {
if (TranslationUnitDecl *TUD = dyn_cast<TranslationUnitDecl>(this))
return TUD;
DeclContext *DC = getDeclContext();
assert(DC && "This decl is not contained in a translation unit!");
while (!DC->isTranslationUnit()) {
DC = DC->getParent();
assert(DC && "This decl is not contained in a translation unit!");
}
return cast<TranslationUnitDecl>(DC);
}
ASTContext &Decl::getASTContext() const {
return getTranslationUnitDecl()->getASTContext();
}
ASTMutationListener *Decl::getASTMutationListener() const {
return getASTContext().getASTMutationListener();
}
unsigned Decl::getMaxAlignment() const {
if (!hasAttrs())
return 0;
unsigned Align = 0;
const AttrVec &V = getAttrs();
ASTContext &Ctx = getASTContext();
specific_attr_iterator<AlignedAttr> I(V.begin()), E(V.end());
for (; I != E; ++I)
Align = std::max(Align, I->getAlignment(Ctx));
return Align;
}
bool Decl::isUsed(bool CheckUsedAttr) const {
if (Used)
return true;
// Check for used attribute.
if (CheckUsedAttr && hasAttr<UsedAttr>())
return true;
return false;
}
bool Decl::isReferenced() const {
if (Referenced)
return true;
// Check redeclarations.
for (redecl_iterator I = redecls_begin(), E = redecls_end(); I != E; ++I)
if (I->Referenced)
return true;
return false;
}
/// \brief Determine the availability of the given declaration based on
/// the target platform.
///
/// When it returns an availability result other than \c AR_Available,
/// if the \p Message parameter is non-NULL, it will be set to a
/// string describing why the entity is unavailable.
///
/// FIXME: Make these strings localizable, since they end up in
/// diagnostics.
static AvailabilityResult CheckAvailability(ASTContext &Context,
const AvailabilityAttr *A,
std::string *Message) {
StringRef TargetPlatform = Context.getTargetInfo().getPlatformName();
StringRef PrettyPlatformName
= AvailabilityAttr::getPrettyPlatformName(TargetPlatform);
if (PrettyPlatformName.empty())
PrettyPlatformName = TargetPlatform;
VersionTuple TargetMinVersion = Context.getTargetInfo().getPlatformMinVersion();
if (TargetMinVersion.empty())
return AR_Available;
// Match the platform name.
if (A->getPlatform()->getName() != TargetPlatform)
return AR_Available;
std::string HintMessage;
if (!A->getMessage().empty()) {
HintMessage = " - ";
HintMessage += A->getMessage();
}
// Make sure that this declaration has not been marked 'unavailable'.
if (A->getUnavailable()) {
if (Message) {
Message->clear();
llvm::raw_string_ostream Out(*Message);
Out << "not available on " << PrettyPlatformName
<< HintMessage;
}
return AR_Unavailable;
}
// Make sure that this declaration has already been introduced.
if (!A->getIntroduced().empty() &&
TargetMinVersion < A->getIntroduced()) {
if (Message) {
Message->clear();
llvm::raw_string_ostream Out(*Message);
Out << "introduced in " << PrettyPlatformName << ' '
<< A->getIntroduced() << HintMessage;
}
return AR_NotYetIntroduced;
}
// Make sure that this declaration hasn't been obsoleted.
if (!A->getObsoleted().empty() && TargetMinVersion >= A->getObsoleted()) {
if (Message) {
Message->clear();
llvm::raw_string_ostream Out(*Message);
Out << "obsoleted in " << PrettyPlatformName << ' '
<< A->getObsoleted() << HintMessage;
}
return AR_Unavailable;
}
// Make sure that this declaration hasn't been deprecated.
if (!A->getDeprecated().empty() && TargetMinVersion >= A->getDeprecated()) {
if (Message) {
Message->clear();
llvm::raw_string_ostream Out(*Message);
Out << "first deprecated in " << PrettyPlatformName << ' '
<< A->getDeprecated() << HintMessage;
}
return AR_Deprecated;
}
return AR_Available;
}
AvailabilityResult Decl::getAvailability(std::string *Message) const {
AvailabilityResult Result = AR_Available;
std::string ResultMessage;
for (attr_iterator A = attr_begin(), AEnd = attr_end(); A != AEnd; ++A) {
if (DeprecatedAttr *Deprecated = dyn_cast<DeprecatedAttr>(*A)) {
if (Result >= AR_Deprecated)
continue;
if (Message)
ResultMessage = Deprecated->getMessage();
Result = AR_Deprecated;
continue;
}
if (UnavailableAttr *Unavailable = dyn_cast<UnavailableAttr>(*A)) {
if (Message)
*Message = Unavailable->getMessage();
return AR_Unavailable;
}
if (AvailabilityAttr *Availability = dyn_cast<AvailabilityAttr>(*A)) {
AvailabilityResult AR = CheckAvailability(getASTContext(), Availability,
Message);
if (AR == AR_Unavailable)
return AR_Unavailable;
if (AR > Result) {
Result = AR;
if (Message)
ResultMessage.swap(*Message);
}
continue;
}
}
if (Message)
Message->swap(ResultMessage);
return Result;
}
bool Decl::canBeWeakImported(bool &IsDefinition) const {
IsDefinition = false;
// Variables, if they aren't definitions.
if (const VarDecl *Var = dyn_cast<VarDecl>(this)) {
if (Var->isThisDeclarationADefinition()) {
IsDefinition = true;
return false;
}
return true;
// Functions, if they aren't definitions.
} else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(this)) {
if (FD->hasBody()) {
IsDefinition = true;
return false;
}
return true;
// Objective-C classes, if this is the non-fragile runtime.
} else if (isa<ObjCInterfaceDecl>(this) &&
getASTContext().getLangOpts().ObjCRuntime.hasWeakClassImport()) {
return true;
// Nothing else.
} else {
return false;
}
}
bool Decl::isWeakImported() const {
bool IsDefinition;
if (!canBeWeakImported(IsDefinition))
return false;
for (attr_iterator A = attr_begin(), AEnd = attr_end(); A != AEnd; ++A) {
if (isa<WeakImportAttr>(*A))
return true;
if (AvailabilityAttr *Availability = dyn_cast<AvailabilityAttr>(*A)) {
if (CheckAvailability(getASTContext(), Availability, 0)
== AR_NotYetIntroduced)
return true;
}
}
return false;
}
unsigned Decl::getIdentifierNamespaceForKind(Kind DeclKind) {
switch (DeclKind) {
case Function:
case CXXMethod:
case CXXConstructor:
case CXXDestructor:
case CXXConversion:
case EnumConstant:
case Var:
case ImplicitParam:
case ParmVar:
case NonTypeTemplateParm:
case ObjCMethod:
case ObjCProperty:
case MSProperty:
return IDNS_Ordinary;
case Label:
return IDNS_Label;
case IndirectField:
return IDNS_Ordinary | IDNS_Member;
case ObjCCompatibleAlias:
case ObjCInterface:
return IDNS_Ordinary | IDNS_Type;
case Typedef:
case TypeAlias:
case TypeAliasTemplate:
case UnresolvedUsingTypename:
case TemplateTypeParm:
return IDNS_Ordinary | IDNS_Type;
case UsingShadow:
return 0; // we'll actually overwrite this later
case UnresolvedUsingValue:
return IDNS_Ordinary | IDNS_Using;
case Using:
return IDNS_Using;
case ObjCProtocol:
return IDNS_ObjCProtocol;
case Field:
case ObjCAtDefsField:
case ObjCIvar:
return IDNS_Member;
case Record:
case CXXRecord:
case Enum:
return IDNS_Tag | IDNS_Type;
case Namespace:
case NamespaceAlias:
return IDNS_Namespace;
case FunctionTemplate:
return IDNS_Ordinary;
case ClassTemplate:
case TemplateTemplateParm:
return IDNS_Ordinary | IDNS_Tag | IDNS_Type;
// Never have names.
case Friend:
case FriendTemplate:
case AccessSpec:
case LinkageSpec:
case FileScopeAsm:
case StaticAssert:
case ObjCPropertyImpl:
case Block:
case Captured:
case TranslationUnit:
case UsingDirective:
case ClassTemplateSpecialization:
case ClassTemplatePartialSpecialization:
case ClassScopeFunctionSpecialization:
case ObjCImplementation:
case ObjCCategory:
case ObjCCategoryImpl:
case Import:
case OMPThreadPrivate:
case Empty:
// Never looked up by name.
return 0;
}
llvm_unreachable("Invalid DeclKind!");
}
void Decl::setAttrsImpl(const AttrVec &attrs, ASTContext &Ctx) {
assert(!HasAttrs && "Decl already contains attrs.");
AttrVec &AttrBlank = Ctx.getDeclAttrs(this);
assert(AttrBlank.empty() && "HasAttrs was wrong?");
AttrBlank = attrs;
HasAttrs = true;
}
void Decl::dropAttrs() {
if (!HasAttrs) return;
HasAttrs = false;
getASTContext().eraseDeclAttrs(this);
}
const AttrVec &Decl::getAttrs() const {
assert(HasAttrs && "No attrs to get!");
return getASTContext().getDeclAttrs(this);
}
Decl *Decl::castFromDeclContext (const DeclContext *D) {
Decl::Kind DK = D->getDeclKind();
switch(DK) {
#define DECL(NAME, BASE)
#define DECL_CONTEXT(NAME) \
case Decl::NAME: \
return static_cast<NAME##Decl*>(const_cast<DeclContext*>(D));
#define DECL_CONTEXT_BASE(NAME)
#include "clang/AST/DeclNodes.inc"
default:
#define DECL(NAME, BASE)
#define DECL_CONTEXT_BASE(NAME) \
if (DK >= first##NAME && DK <= last##NAME) \
return static_cast<NAME##Decl*>(const_cast<DeclContext*>(D));
#include "clang/AST/DeclNodes.inc"
llvm_unreachable("a decl that inherits DeclContext isn't handled");
}
}
DeclContext *Decl::castToDeclContext(const Decl *D) {
Decl::Kind DK = D->getKind();
switch(DK) {
#define DECL(NAME, BASE)
#define DECL_CONTEXT(NAME) \
case Decl::NAME: \
return static_cast<NAME##Decl*>(const_cast<Decl*>(D));
#define DECL_CONTEXT_BASE(NAME)
#include "clang/AST/DeclNodes.inc"
default:
#define DECL(NAME, BASE)
#define DECL_CONTEXT_BASE(NAME) \
if (DK >= first##NAME && DK <= last##NAME) \
return static_cast<NAME##Decl*>(const_cast<Decl*>(D));
#include "clang/AST/DeclNodes.inc"
llvm_unreachable("a decl that inherits DeclContext isn't handled");
}
}
SourceLocation Decl::getBodyRBrace() const {
// Special handling of FunctionDecl to avoid de-serializing the body from PCH.
// FunctionDecl stores EndRangeLoc for this purpose.
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(this)) {
const FunctionDecl *Definition;
if (FD->hasBody(Definition))
return Definition->getSourceRange().getEnd();
return SourceLocation();
}
if (Stmt *Body = getBody())
return Body->getSourceRange().getEnd();
return SourceLocation();
}
void Decl::CheckAccessDeclContext() const {
#ifndef NDEBUG
// Suppress this check if any of the following hold:
// 1. this is the translation unit (and thus has no parent)
// 2. this is a template parameter (and thus doesn't belong to its context)
// 3. this is a non-type template parameter
// 4. the context is not a record
// 5. it's invalid
// 6. it's a C++0x static_assert.
if (isa<TranslationUnitDecl>(this) ||
isa<TemplateTypeParmDecl>(this) ||
isa<NonTypeTemplateParmDecl>(this) ||
!isa<CXXRecordDecl>(getDeclContext()) ||
isInvalidDecl() ||
isa<StaticAssertDecl>(this) ||
// FIXME: a ParmVarDecl can have ClassTemplateSpecialization
// as DeclContext (?).
isa<ParmVarDecl>(this) ||
// FIXME: a ClassTemplateSpecialization or CXXRecordDecl can have
// AS_none as access specifier.
isa<CXXRecordDecl>(this) ||
isa<ClassScopeFunctionSpecializationDecl>(this))
return;
assert(Access != AS_none &&
"Access specifier is AS_none inside a record decl");
#endif
}
static Decl::Kind getKind(const Decl *D) { return D->getKind(); }
static Decl::Kind getKind(const DeclContext *DC) { return DC->getDeclKind(); }
/// Starting at a given context (a Decl or DeclContext), look for a
/// code context that is not a closure (a lambda, block, etc.).
template <class T> static Decl *getNonClosureContext(T *D) {
if (getKind(D) == Decl::CXXMethod) {
CXXMethodDecl *MD = cast<CXXMethodDecl>(D);
if (MD->getOverloadedOperator() == OO_Call &&
MD->getParent()->isLambda())
return getNonClosureContext(MD->getParent()->getParent());
return MD;
} else if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
return FD;
} else if (ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) {
return MD;
} else if (BlockDecl *BD = dyn_cast<BlockDecl>(D)) {
return getNonClosureContext(BD->getParent());
} else if (CapturedDecl *CD = dyn_cast<CapturedDecl>(D)) {
return getNonClosureContext(CD->getParent());
} else {
return 0;
}
}
Decl *Decl::getNonClosureContext() {
return ::getNonClosureContext(this);
}
Decl *DeclContext::getNonClosureAncestor() {
return ::getNonClosureContext(this);
}
//===----------------------------------------------------------------------===//
// DeclContext Implementation
//===----------------------------------------------------------------------===//
bool DeclContext::classof(const Decl *D) {
switch (D->getKind()) {
#define DECL(NAME, BASE)
#define DECL_CONTEXT(NAME) case Decl::NAME:
#define DECL_CONTEXT_BASE(NAME)
#include "clang/AST/DeclNodes.inc"
return true;
default:
#define DECL(NAME, BASE)
#define DECL_CONTEXT_BASE(NAME) \
if (D->getKind() >= Decl::first##NAME && \
D->getKind() <= Decl::last##NAME) \
return true;
#include "clang/AST/DeclNodes.inc"
return false;
}
}
DeclContext::~DeclContext() { }
/// \brief Find the parent context of this context that will be
/// used for unqualified name lookup.
///
/// Generally, the parent lookup context is the semantic context. However, for
/// a friend function the parent lookup context is the lexical context, which
/// is the class in which the friend is declared.
DeclContext *DeclContext::getLookupParent() {
// FIXME: Find a better way to identify friends
if (isa<FunctionDecl>(this))
if (getParent()->getRedeclContext()->isFileContext() &&
getLexicalParent()->getRedeclContext()->isRecord())
return getLexicalParent();
return getParent();
}
bool DeclContext::isInlineNamespace() const {
return isNamespace() &&
cast<NamespaceDecl>(this)->isInline();
}
bool DeclContext::isDependentContext() const {
if (isFileContext())
return false;
if (isa<ClassTemplatePartialSpecializationDecl>(this))
return true;
if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(this)) {
if (Record->getDescribedClassTemplate())
return true;
if (Record->isDependentLambda())
return true;
}
if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(this)) {
if (Function->getDescribedFunctionTemplate())
return true;
// Friend function declarations are dependent if their *lexical*
// context is dependent.
if (cast<Decl>(this)->getFriendObjectKind())
return getLexicalParent()->isDependentContext();
}
return getParent() && getParent()->isDependentContext();
}
bool DeclContext::isTransparentContext() const {
if (DeclKind == Decl::Enum)
return !cast<EnumDecl>(this)->isScoped();
else if (DeclKind == Decl::LinkageSpec)
return true;
return false;
}
bool DeclContext::Encloses(const DeclContext *DC) const {
if (getPrimaryContext() != this)
return getPrimaryContext()->Encloses(DC);
for (; DC; DC = DC->getParent())
if (DC->getPrimaryContext() == this)
return true;
return false;
}
DeclContext *DeclContext::getPrimaryContext() {
switch (DeclKind) {
case Decl::TranslationUnit:
case Decl::LinkageSpec:
case Decl::Block:
case Decl::Captured:
// There is only one DeclContext for these entities.
return this;
case Decl::Namespace:
// The original namespace is our primary context.
return static_cast<NamespaceDecl*>(this)->getOriginalNamespace();
case Decl::ObjCMethod:
return this;
case Decl::ObjCInterface:
if (ObjCInterfaceDecl *Def = cast<ObjCInterfaceDecl>(this)->getDefinition())
return Def;
return this;
case Decl::ObjCProtocol:
if (ObjCProtocolDecl *Def = cast<ObjCProtocolDecl>(this)->getDefinition())
return Def;
return this;
case Decl::ObjCCategory:
return this;
case Decl::ObjCImplementation:
case Decl::ObjCCategoryImpl:
return this;
default:
if (DeclKind >= Decl::firstTag && DeclKind <= Decl::lastTag) {
// If this is a tag type that has a definition or is currently
// being defined, that definition is our primary context.
TagDecl *Tag = cast<TagDecl>(this);
assert(isa<TagType>(Tag->TypeForDecl) ||
isa<InjectedClassNameType>(Tag->TypeForDecl));
if (TagDecl *Def = Tag->getDefinition())
return Def;
if (!isa<InjectedClassNameType>(Tag->TypeForDecl)) {
const TagType *TagTy = cast<TagType>(Tag->TypeForDecl);
if (TagTy->isBeingDefined())
// FIXME: is it necessarily being defined in the decl
// that owns the type?
return TagTy->getDecl();
}
return Tag;
}
assert(DeclKind >= Decl::firstFunction && DeclKind <= Decl::lastFunction &&
"Unknown DeclContext kind");
return this;
}
}
void
DeclContext::collectAllContexts(SmallVectorImpl<DeclContext *> &Contexts){
Contexts.clear();
if (DeclKind != Decl::Namespace) {
Contexts.push_back(this);
return;
}
NamespaceDecl *Self = static_cast<NamespaceDecl *>(this);
for (NamespaceDecl *N = Self->getMostRecentDecl(); N;
N = N->getPreviousDecl())
Contexts.push_back(N);
std::reverse(Contexts.begin(), Contexts.end());
}
std::pair<Decl *, Decl *>
DeclContext::BuildDeclChain(ArrayRef<Decl*> Decls,
bool FieldsAlreadyLoaded) {
// Build up a chain of declarations via the Decl::NextInContextAndBits field.
Decl *FirstNewDecl = 0;
Decl *PrevDecl = 0;
for (unsigned I = 0, N = Decls.size(); I != N; ++I) {
if (FieldsAlreadyLoaded && isa<FieldDecl>(Decls[I]))
continue;
Decl *D = Decls[I];
if (PrevDecl)
PrevDecl->NextInContextAndBits.setPointer(D);
else
FirstNewDecl = D;
PrevDecl = D;
}
return std::make_pair(FirstNewDecl, PrevDecl);
}
/// \brief We have just acquired external visible storage, and we already have
/// built a lookup map. For every name in the map, pull in the new names from
/// the external storage.
void DeclContext::reconcileExternalVisibleStorage() {
assert(NeedToReconcileExternalVisibleStorage && LookupPtr.getPointer());
NeedToReconcileExternalVisibleStorage = false;
StoredDeclsMap &Map = *LookupPtr.getPointer();
ExternalASTSource *Source = getParentASTContext().getExternalSource();
for (StoredDeclsMap::iterator I = Map.begin(); I != Map.end(); ++I) {
I->second.removeExternalDecls();
Source->FindExternalVisibleDeclsByName(this, I->first);
}
}
/// \brief Load the declarations within this lexical storage from an
/// external source.
void
DeclContext::LoadLexicalDeclsFromExternalStorage() const {
ExternalASTSource *Source = getParentASTContext().getExternalSource();
assert(hasExternalLexicalStorage() && Source && "No external storage?");
// Notify that we have a DeclContext that is initializing.
ExternalASTSource::Deserializing ADeclContext(Source);
// Load the external declarations, if any.
SmallVector<Decl*, 64> Decls;
ExternalLexicalStorage = false;
switch (Source->FindExternalLexicalDecls(this, Decls)) {
case ELR_Success:
break;
case ELR_Failure:
case ELR_AlreadyLoaded:
return;
}
if (Decls.empty())
return;
// We may have already loaded just the fields of this record, in which case
// we need to ignore them.
bool FieldsAlreadyLoaded = false;
if (const RecordDecl *RD = dyn_cast<RecordDecl>(this))
FieldsAlreadyLoaded = RD->LoadedFieldsFromExternalStorage;
// Splice the newly-read declarations into the beginning of the list
// of declarations.
Decl *ExternalFirst, *ExternalLast;
llvm::tie(ExternalFirst, ExternalLast) = BuildDeclChain(Decls,
FieldsAlreadyLoaded);
ExternalLast->NextInContextAndBits.setPointer(FirstDecl);
FirstDecl = ExternalFirst;
if (!LastDecl)
LastDecl = ExternalLast;
}
DeclContext::lookup_result
ExternalASTSource::SetNoExternalVisibleDeclsForName(const DeclContext *DC,
DeclarationName Name) {
ASTContext &Context = DC->getParentASTContext();
StoredDeclsMap *Map;
if (!(Map = DC->LookupPtr.getPointer()))
Map = DC->CreateStoredDeclsMap(Context);
// Add an entry to the map for this name, if it's not already present.
(*Map)[Name];
return DeclContext::lookup_result();
}
DeclContext::lookup_result
ExternalASTSource::SetExternalVisibleDeclsForName(const DeclContext *DC,
DeclarationName Name,
ArrayRef<NamedDecl*> Decls) {
ASTContext &Context = DC->getParentASTContext();
StoredDeclsMap *Map;
if (!(Map = DC->LookupPtr.getPointer()))
Map = DC->CreateStoredDeclsMap(Context);
StoredDeclsList &List = (*Map)[Name];
// Clear out any old external visible declarations, to avoid quadratic
// performance in the redeclaration checks below.
List.removeExternalDecls();
if (!List.isNull()) {
// We have both existing declarations and new declarations for this name.
// Some of the declarations may simply replace existing ones. Handle those
// first.
llvm::SmallVector<unsigned, 8> Skip;
for (unsigned I = 0, N = Decls.size(); I != N; ++I)
if (List.HandleRedeclaration(Decls[I]))
Skip.push_back(I);
Skip.push_back(Decls.size());
// Add in any new declarations.
unsigned SkipPos = 0;
for (unsigned I = 0, N = Decls.size(); I != N; ++I) {
if (I == Skip[SkipPos])
++SkipPos;
else
List.AddSubsequentDecl(Decls[I]);
}
} else {
// Convert the array to a StoredDeclsList.
for (ArrayRef<NamedDecl*>::iterator
I = Decls.begin(), E = Decls.end(); I != E; ++I) {
if (List.isNull())
List.setOnlyValue(*I);
else
List.AddSubsequentDecl(*I);
}
}
return List.getLookupResult();
}
DeclContext::decl_iterator DeclContext::noload_decls_begin() const {
return decl_iterator(FirstDecl);
}
DeclContext::decl_iterator DeclContext::decls_begin() const {
if (hasExternalLexicalStorage())
LoadLexicalDeclsFromExternalStorage();
return decl_iterator(FirstDecl);
}
bool DeclContext::decls_empty() const {
if (hasExternalLexicalStorage())
LoadLexicalDeclsFromExternalStorage();
return !FirstDecl;
}
bool DeclContext::containsDecl(Decl *D) const {
return (D->getLexicalDeclContext() == this &&
(D->NextInContextAndBits.getPointer() || D == LastDecl));
}
void DeclContext::removeDecl(Decl *D) {
assert(D->getLexicalDeclContext() == this &&
"decl being removed from non-lexical context");
assert((D->NextInContextAndBits.getPointer() || D == LastDecl) &&
"decl is not in decls list");
// Remove D from the decl chain. This is O(n) but hopefully rare.
if (D == FirstDecl) {
if (D == LastDecl)
FirstDecl = LastDecl = 0;
else
FirstDecl = D->NextInContextAndBits.getPointer();
} else {
for (Decl *I = FirstDecl; true; I = I->NextInContextAndBits.getPointer()) {
assert(I && "decl not found in linked list");
if (I->NextInContextAndBits.getPointer() == D) {
I->NextInContextAndBits.setPointer(D->NextInContextAndBits.getPointer());
if (D == LastDecl) LastDecl = I;
break;
}
}
}
// Mark that D is no longer in the decl chain.
D->NextInContextAndBits.setPointer(0);
// Remove D from the lookup table if necessary.
if (isa<NamedDecl>(D)) {
NamedDecl *ND = cast<NamedDecl>(D);
// Remove only decls that have a name
if (!ND->getDeclName()) return;
StoredDeclsMap *Map = getPrimaryContext()->LookupPtr.getPointer();
if (!Map) return;
StoredDeclsMap::iterator Pos = Map->find(ND->getDeclName());
assert(Pos != Map->end() && "no lookup entry for decl");
if (Pos->second.getAsVector() || Pos->second.getAsDecl() == ND)
Pos->second.remove(ND);
}
}
void DeclContext::addHiddenDecl(Decl *D) {
assert(D->getLexicalDeclContext() == this &&
"Decl inserted into wrong lexical context");
assert(!D->getNextDeclInContext() && D != LastDecl &&
"Decl already inserted into a DeclContext");
if (FirstDecl) {
LastDecl->NextInContextAndBits.setPointer(D);
LastDecl = D;
} else {
FirstDecl = LastDecl = D;
}
// Notify a C++ record declaration that we've added a member, so it can
// update it's class-specific state.
if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(this))
Record->addedMember(D);
// If this is a newly-created (not de-serialized) import declaration, wire
// it in to the list of local import declarations.
if (!D->isFromASTFile()) {
if (ImportDecl *Import = dyn_cast<ImportDecl>(D))
D->getASTContext().addedLocalImportDecl(Import);
}
}
void DeclContext::addDecl(Decl *D) {
addHiddenDecl(D);
if (NamedDecl *ND = dyn_cast<NamedDecl>(D))
ND->getDeclContext()->getPrimaryContext()->
makeDeclVisibleInContextWithFlags(ND, false, true);
}
void DeclContext::addDeclInternal(Decl *D) {
addHiddenDecl(D);
if (NamedDecl *ND = dyn_cast<NamedDecl>(D))
ND->getDeclContext()->getPrimaryContext()->
makeDeclVisibleInContextWithFlags(ND, true, true);
}
/// shouldBeHidden - Determine whether a declaration which was declared
/// within its semantic context should be invisible to qualified name lookup.
static bool shouldBeHidden(NamedDecl *D) {
// Skip unnamed declarations.
if (!D->getDeclName())
return true;
// Skip entities that can't be found by name lookup into a particular
// context.
if ((D->getIdentifierNamespace() == 0 && !isa<UsingDirectiveDecl>(D)) ||
D->isTemplateParameter())
return true;
// Skip template specializations.
// FIXME: This feels like a hack. Should DeclarationName support
// template-ids, or is there a better way to keep specializations
// from being visible?
if (isa<ClassTemplateSpecializationDecl>(D))
return true;
if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
if (FD->isFunctionTemplateSpecialization())
return true;
return false;
}
/// buildLookup - Build the lookup data structure with all of the
/// declarations in this DeclContext (and any other contexts linked
/// to it or transparent contexts nested within it) and return it.
StoredDeclsMap *DeclContext::buildLookup() {
assert(this == getPrimaryContext() && "buildLookup called on non-primary DC");
// FIXME: Should we keep going if hasExternalVisibleStorage?
if (!LookupPtr.getInt())
return LookupPtr.getPointer();
SmallVector<DeclContext *, 2> Contexts;
collectAllContexts(Contexts);
for (unsigned I = 0, N = Contexts.size(); I != N; ++I)
buildLookupImpl<&DeclContext::decls_begin,
&DeclContext::decls_end>(Contexts[I]);
// We no longer have any lazy decls.
LookupPtr.setInt(false);
NeedToReconcileExternalVisibleStorage = false;
return LookupPtr.getPointer();
}
/// buildLookupImpl - Build part of the lookup data structure for the
/// declarations contained within DCtx, which will either be this
/// DeclContext, a DeclContext linked to it, or a transparent context
/// nested within it.
template<DeclContext::decl_iterator (DeclContext::*Begin)() const,
DeclContext::decl_iterator (DeclContext::*End)() const>
void DeclContext::buildLookupImpl(DeclContext *DCtx) {
for (decl_iterator I = (DCtx->*Begin)(), E = (DCtx->*End)();
I != E; ++I) {
Decl *D = *I;
// Insert this declaration into the lookup structure, but only if
// it's semantically within its decl context. Any other decls which
// should be found in this context are added eagerly.
//
// If it's from an AST file, don't add it now. It'll get handled by
// FindExternalVisibleDeclsByName if needed. Exception: if we're not
// in C++, we do not track external visible decls for the TU, so in
// that case we need to collect them all here.
if (NamedDecl *ND = dyn_cast<NamedDecl>(D))
if (ND->getDeclContext() == DCtx && !shouldBeHidden(ND) &&
(!ND->isFromASTFile() ||
(isTranslationUnit() &&
!getParentASTContext().getLangOpts().CPlusPlus)))
makeDeclVisibleInContextImpl(ND, false);
// If this declaration is itself a transparent declaration context
// or inline namespace, add the members of this declaration of that
// context (recursively).
if (DeclContext *InnerCtx = dyn_cast<DeclContext>(D))
if (InnerCtx->isTransparentContext() || InnerCtx->isInlineNamespace())
buildLookupImpl<Begin, End>(InnerCtx);
}
}
DeclContext::lookup_result
DeclContext::lookup(DeclarationName Name) {
assert(DeclKind != Decl::LinkageSpec &&
"Should not perform lookups into linkage specs!");
DeclContext *PrimaryContext = getPrimaryContext();
if (PrimaryContext != this)
return PrimaryContext->lookup(Name);
if (hasExternalVisibleStorage()) {
StoredDeclsMap *Map = LookupPtr.getPointer();
if (LookupPtr.getInt())
Map = buildLookup();
else if (NeedToReconcileExternalVisibleStorage)
reconcileExternalVisibleStorage();
if (!Map)
Map = CreateStoredDeclsMap(getParentASTContext());
// If a PCH/module has a result for this name, and we have a local
// declaration, we will have imported the PCH/module result when adding the
// local declaration or when reconciling the module.
std::pair<StoredDeclsMap::iterator, bool> R =
Map->insert(std::make_pair(Name, StoredDeclsList()));
if (!R.second)
return R.first->second.getLookupResult();
ExternalASTSource *Source = getParentASTContext().getExternalSource();
if (Source->FindExternalVisibleDeclsByName(this, Name)) {
if (StoredDeclsMap *Map = LookupPtr.getPointer()) {
StoredDeclsMap::iterator I = Map->find(Name);
if (I != Map->end())
return I->second.getLookupResult();
}
}
return lookup_result(lookup_iterator(0), lookup_iterator(0));
}
StoredDeclsMap *Map = LookupPtr.getPointer();
if (LookupPtr.getInt())
Map = buildLookup();
if (!Map)
return lookup_result(lookup_iterator(0), lookup_iterator(0));
StoredDeclsMap::iterator I = Map->find(Name);
if (I == Map->end())
return lookup_result(lookup_iterator(0), lookup_iterator(0));
return I->second.getLookupResult();
}
DeclContext::lookup_result
DeclContext::noload_lookup(DeclarationName Name) {
assert(DeclKind != Decl::LinkageSpec &&
"Should not perform lookups into linkage specs!");
if (!hasExternalVisibleStorage())
return lookup(Name);
DeclContext *PrimaryContext = getPrimaryContext();
if (PrimaryContext != this)
return PrimaryContext->noload_lookup(Name);
StoredDeclsMap *Map = LookupPtr.getPointer();
if (LookupPtr.getInt()) {
// Carefully build the lookup map, without deserializing anything.
SmallVector<DeclContext *, 2> Contexts;
collectAllContexts(Contexts);
for (unsigned I = 0, N = Contexts.size(); I != N; ++I)
buildLookupImpl<&DeclContext::noload_decls_begin,
&DeclContext::noload_decls_end>(Contexts[I]);
// We no longer have any lazy decls.
LookupPtr.setInt(false);
// There may now be names for which we have local decls but are
// missing the external decls.
NeedToReconcileExternalVisibleStorage = true;
Map = LookupPtr.getPointer();
}
if (!Map)
return lookup_result(lookup_iterator(0), lookup_iterator(0));
StoredDeclsMap::iterator I = Map->find(Name);
return I != Map->end()
? I->second.getLookupResult()
: lookup_result(lookup_iterator(0), lookup_iterator(0));
}
void DeclContext::localUncachedLookup(DeclarationName Name,
SmallVectorImpl<NamedDecl *> &Results) {
Results.clear();
// If there's no external storage, just perform a normal lookup and copy
// the results.
if (!hasExternalVisibleStorage() && !hasExternalLexicalStorage() && Name) {
lookup_result LookupResults = lookup(Name);
Results.insert(Results.end(), LookupResults.begin(), LookupResults.end());
return;
}
// If we have a lookup table, check there first. Maybe we'll get lucky.
if (Name && !LookupPtr.getInt()) {
if (StoredDeclsMap *Map = LookupPtr.getPointer()) {
StoredDeclsMap::iterator Pos = Map->find(Name);
if (Pos != Map->end()) {
Results.insert(Results.end(),
Pos->second.getLookupResult().begin(),
Pos->second.getLookupResult().end());
return;
}
}
}
// Slow case: grovel through the declarations in our chain looking for
// matches.
for (Decl *D = FirstDecl; D; D = D->getNextDeclInContext()) {
if (NamedDecl *ND = dyn_cast<NamedDecl>(D))
if (ND->getDeclName() == Name)
Results.push_back(ND);
}
}
DeclContext *DeclContext::getRedeclContext() {
DeclContext *Ctx = this;
// Skip through transparent contexts.
while (Ctx->isTransparentContext())
Ctx = Ctx->getParent();
return Ctx;
}
DeclContext *DeclContext::getEnclosingNamespaceContext() {
DeclContext *Ctx = this;
// Skip through non-namespace, non-translation-unit contexts.
while (!Ctx->isFileContext())
Ctx = Ctx->getParent();
return Ctx->getPrimaryContext();
}
bool DeclContext::InEnclosingNamespaceSetOf(const DeclContext *O) const {
// For non-file contexts, this is equivalent to Equals.
if (!isFileContext())
return O->Equals(this);
do {
if (O->Equals(this))
return true;
const NamespaceDecl *NS = dyn_cast<NamespaceDecl>(O);
if (!NS || !NS->isInline())
break;
O = NS->getParent();
} while (O);
return false;
}
void DeclContext::makeDeclVisibleInContext(NamedDecl *D) {
DeclContext *PrimaryDC = this->getPrimaryContext();
DeclContext *DeclDC = D->getDeclContext()->getPrimaryContext();
// If the decl is being added outside of its semantic decl context, we
// need to ensure that we eagerly build the lookup information for it.
PrimaryDC->makeDeclVisibleInContextWithFlags(D, false, PrimaryDC == DeclDC);
}
void DeclContext::makeDeclVisibleInContextWithFlags(NamedDecl *D, bool Internal,
bool Recoverable) {
assert(this == getPrimaryContext() && "expected a primary DC");
// Skip declarations within functions.
// FIXME: We shouldn't need to build lookup tables for function declarations
// ever, and we can't do so correctly because we can't model the nesting of
// scopes which occurs within functions. We use "qualified" lookup into
// function declarations when handling friend declarations inside nested
// classes, and consequently accept the following invalid code:
//
// void f() { void g(); { int g; struct S { friend void g(); }; } }
if (isFunctionOrMethod() && !isa<FunctionDecl>(D))
return;
// Skip declarations which should be invisible to name lookup.
if (shouldBeHidden(D))
return;
// If we already have a lookup data structure, perform the insertion into
// it. If we might have externally-stored decls with this name, look them
// up and perform the insertion. If this decl was declared outside its
// semantic context, buildLookup won't add it, so add it now.
//
// FIXME: As a performance hack, don't add such decls into the translation
// unit unless we're in C++, since qualified lookup into the TU is never
// performed.
if (LookupPtr.getPointer() || hasExternalVisibleStorage() ||
((!Recoverable || D->getDeclContext() != D->getLexicalDeclContext()) &&
(getParentASTContext().getLangOpts().CPlusPlus ||
!isTranslationUnit()))) {
// If we have lazily omitted any decls, they might have the same name as
// the decl which we are adding, so build a full lookup table before adding
// this decl.
buildLookup();
makeDeclVisibleInContextImpl(D, Internal);
} else {
LookupPtr.setInt(true);
}
// If we are a transparent context or inline namespace, insert into our
// parent context, too. This operation is recursive.
if (isTransparentContext() || isInlineNamespace())
getParent()->getPrimaryContext()->
makeDeclVisibleInContextWithFlags(D, Internal, Recoverable);
Decl *DCAsDecl = cast<Decl>(this);
// Notify that a decl was made visible unless we are a Tag being defined.
if (!(isa<TagDecl>(DCAsDecl) && cast<TagDecl>(DCAsDecl)->isBeingDefined()))
if (ASTMutationListener *L = DCAsDecl->getASTMutationListener())
L->AddedVisibleDecl(this, D);
}
void DeclContext::makeDeclVisibleInContextImpl(NamedDecl *D, bool Internal) {
// Find or create the stored declaration map.
StoredDeclsMap *Map = LookupPtr.getPointer();
if (!Map) {
ASTContext *C = &getParentASTContext();
Map = CreateStoredDeclsMap(*C);
}
// If there is an external AST source, load any declarations it knows about
// with this declaration's name.
// If the lookup table contains an entry about this name it means that we
// have already checked the external source.
if (!Internal)
if (ExternalASTSource *Source = getParentASTContext().getExternalSource())
if (hasExternalVisibleStorage() &&
Map->find(D->getDeclName()) == Map->end())
Source->FindExternalVisibleDeclsByName(this, D->getDeclName());
// Insert this declaration into the map.
StoredDeclsList &DeclNameEntries = (*Map)[D->getDeclName()];
if (DeclNameEntries.isNull()) {
DeclNameEntries.setOnlyValue(D);
return;
}
if (DeclNameEntries.HandleRedeclaration(D)) {
// This declaration has replaced an existing one for which
// declarationReplaces returns true.
return;
}
// Put this declaration into the appropriate slot.
DeclNameEntries.AddSubsequentDecl(D);
}
/// Returns iterator range [First, Last) of UsingDirectiveDecls stored within
/// this context.
DeclContext::udir_iterator_range
DeclContext::getUsingDirectives() const {
// FIXME: Use something more efficient than normal lookup for using
// directives. In C++, using directives are looked up more than anything else.
lookup_const_result Result = lookup(UsingDirectiveDecl::getName());
return udir_iterator_range(reinterpret_cast<udir_iterator>(Result.begin()),
reinterpret_cast<udir_iterator>(Result.end()));
}
//===----------------------------------------------------------------------===//
// Creation and Destruction of StoredDeclsMaps. //
//===----------------------------------------------------------------------===//
StoredDeclsMap *DeclContext::CreateStoredDeclsMap(ASTContext &C) const {
assert(!LookupPtr.getPointer() && "context already has a decls map");
assert(getPrimaryContext() == this &&
"creating decls map on non-primary context");
StoredDeclsMap *M;
bool Dependent = isDependentContext();
if (Dependent)
M = new DependentStoredDeclsMap();
else
M = new StoredDeclsMap();
M->Previous = C.LastSDM;
C.LastSDM = llvm::PointerIntPair<StoredDeclsMap*,1>(M, Dependent);
LookupPtr.setPointer(M);
return M;
}
void ASTContext::ReleaseDeclContextMaps() {
// It's okay to delete DependentStoredDeclsMaps via a StoredDeclsMap
// pointer because the subclass doesn't add anything that needs to
// be deleted.
StoredDeclsMap::DestroyAll(LastSDM.getPointer(), LastSDM.getInt());
}
void StoredDeclsMap::DestroyAll(StoredDeclsMap *Map, bool Dependent) {
while (Map) {
// Advance the iteration before we invalidate memory.
llvm::PointerIntPair<StoredDeclsMap*,1> Next = Map->Previous;
if (Dependent)
delete static_cast<DependentStoredDeclsMap*>(Map);
else
delete Map;
Map = Next.getPointer();
Dependent = Next.getInt();
}
}
DependentDiagnostic *DependentDiagnostic::Create(ASTContext &C,
DeclContext *Parent,
const PartialDiagnostic &PDiag) {
assert(Parent->isDependentContext()
&& "cannot iterate dependent diagnostics of non-dependent context");
Parent = Parent->getPrimaryContext();
if (!Parent->LookupPtr.getPointer())
Parent->CreateStoredDeclsMap(C);
DependentStoredDeclsMap *Map
= static_cast<DependentStoredDeclsMap*>(Parent->LookupPtr.getPointer());
// Allocate the copy of the PartialDiagnostic via the ASTContext's
// BumpPtrAllocator, rather than the ASTContext itself.
PartialDiagnostic::Storage *DiagStorage = 0;
if (PDiag.hasStorage())
DiagStorage = new (C) PartialDiagnostic::Storage;
DependentDiagnostic *DD = new (C) DependentDiagnostic(PDiag, DiagStorage);
// TODO: Maybe we shouldn't reverse the order during insertion.
DD->NextDiagnostic = Map->FirstDiagnostic;
Map->FirstDiagnostic = DD;
return DD;
}