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//===- NestedNameSpecifier.cpp - C++ nested name specifiers ---------------===//
//
// 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 defines the NestedNameSpecifier class, which represents
// a C++ nested-name-specifier.
//
//===----------------------------------------------------------------------===//
#include "clang/AST/NestedNameSpecifier.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/DeclTemplate.h"
#include "clang/AST/PrettyPrinter.h"
#include "clang/AST/TemplateName.h"
#include "clang/AST/Type.h"
#include "clang/AST/TypeLoc.h"
#include "clang/Basic/LLVM.h"
#include "clang/Basic/LangOptions.h"
#include "clang/Basic/SourceLocation.h"
#include "llvm/ADT/FoldingSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <cassert>
#include <cstdlib>
#include <cstring>
using namespace clang;
NestedNameSpecifier *
NestedNameSpecifier::FindOrInsert(const ASTContext &Context,
const NestedNameSpecifier &Mockup) {
llvm::FoldingSetNodeID ID;
Mockup.Profile(ID);
void *InsertPos = nullptr;
NestedNameSpecifier *NNS
= Context.NestedNameSpecifiers.FindNodeOrInsertPos(ID, InsertPos);
if (!NNS) {
NNS =
new (Context, alignof(NestedNameSpecifier)) NestedNameSpecifier(Mockup);
Context.NestedNameSpecifiers.InsertNode(NNS, InsertPos);
}
return NNS;
}
NestedNameSpecifier *
NestedNameSpecifier::Create(const ASTContext &Context,
NestedNameSpecifier *Prefix, IdentifierInfo *II) {
assert(II && "Identifier cannot be NULL");
assert((!Prefix || Prefix->isDependent()) && "Prefix must be dependent");
NestedNameSpecifier Mockup;
Mockup.Prefix.setPointer(Prefix);
Mockup.Prefix.setInt(StoredIdentifier);
Mockup.Specifier = II;
return FindOrInsert(Context, Mockup);
}
NestedNameSpecifier *
NestedNameSpecifier::Create(const ASTContext &Context,
NestedNameSpecifier *Prefix,
const NamespaceDecl *NS) {
assert(NS && "Namespace cannot be NULL");
assert((!Prefix ||
(Prefix->getAsType() == nullptr &&
Prefix->getAsIdentifier() == nullptr)) &&
"Broken nested name specifier");
NestedNameSpecifier Mockup;
Mockup.Prefix.setPointer(Prefix);
Mockup.Prefix.setInt(StoredDecl);
Mockup.Specifier = const_cast<NamespaceDecl *>(NS);
return FindOrInsert(Context, Mockup);
}
NestedNameSpecifier *
NestedNameSpecifier::Create(const ASTContext &Context,
NestedNameSpecifier *Prefix,
NamespaceAliasDecl *Alias) {
assert(Alias && "Namespace alias cannot be NULL");
assert((!Prefix ||
(Prefix->getAsType() == nullptr &&
Prefix->getAsIdentifier() == nullptr)) &&
"Broken nested name specifier");
NestedNameSpecifier Mockup;
Mockup.Prefix.setPointer(Prefix);
Mockup.Prefix.setInt(StoredDecl);
Mockup.Specifier = Alias;
return FindOrInsert(Context, Mockup);
}
NestedNameSpecifier *
NestedNameSpecifier::Create(const ASTContext &Context,
NestedNameSpecifier *Prefix,
bool Template, const Type *T) {
assert(T && "Type cannot be NULL");
NestedNameSpecifier Mockup;
Mockup.Prefix.setPointer(Prefix);
Mockup.Prefix.setInt(Template? StoredTypeSpecWithTemplate : StoredTypeSpec);
Mockup.Specifier = const_cast<Type*>(T);
return FindOrInsert(Context, Mockup);
}
NestedNameSpecifier *
NestedNameSpecifier::Create(const ASTContext &Context, IdentifierInfo *II) {
assert(II && "Identifier cannot be NULL");
NestedNameSpecifier Mockup;
Mockup.Prefix.setPointer(nullptr);
Mockup.Prefix.setInt(StoredIdentifier);
Mockup.Specifier = II;
return FindOrInsert(Context, Mockup);
}
NestedNameSpecifier *
NestedNameSpecifier::GlobalSpecifier(const ASTContext &Context) {
if (!Context.GlobalNestedNameSpecifier)
Context.GlobalNestedNameSpecifier =
new (Context, alignof(NestedNameSpecifier)) NestedNameSpecifier();
return Context.GlobalNestedNameSpecifier;
}
NestedNameSpecifier *
NestedNameSpecifier::SuperSpecifier(const ASTContext &Context,
CXXRecordDecl *RD) {
NestedNameSpecifier Mockup;
Mockup.Prefix.setPointer(nullptr);
Mockup.Prefix.setInt(StoredDecl);
Mockup.Specifier = RD;
return FindOrInsert(Context, Mockup);
}
NestedNameSpecifier::SpecifierKind NestedNameSpecifier::getKind() const {
if (!Specifier)
return Global;
switch (Prefix.getInt()) {
case StoredIdentifier:
return Identifier;
case StoredDecl: {
NamedDecl *ND = static_cast<NamedDecl *>(Specifier);
if (isa<CXXRecordDecl>(ND))
return Super;
return isa<NamespaceDecl>(ND) ? Namespace : NamespaceAlias;
}
case StoredTypeSpec:
return TypeSpec;
case StoredTypeSpecWithTemplate:
return TypeSpecWithTemplate;
}
llvm_unreachable("Invalid NNS Kind!");
}
/// Retrieve the namespace stored in this nested name specifier.
NamespaceDecl *NestedNameSpecifier::getAsNamespace() const {
if (Prefix.getInt() == StoredDecl)
return dyn_cast<NamespaceDecl>(static_cast<NamedDecl *>(Specifier));
return nullptr;
}
/// Retrieve the namespace alias stored in this nested name specifier.
NamespaceAliasDecl *NestedNameSpecifier::getAsNamespaceAlias() const {
if (Prefix.getInt() == StoredDecl)
return dyn_cast<NamespaceAliasDecl>(static_cast<NamedDecl *>(Specifier));
return nullptr;
}
/// Retrieve the record declaration stored in this nested name specifier.
CXXRecordDecl *NestedNameSpecifier::getAsRecordDecl() const {
switch (Prefix.getInt()) {
case StoredIdentifier:
return nullptr;
case StoredDecl:
return dyn_cast<CXXRecordDecl>(static_cast<NamedDecl *>(Specifier));
case StoredTypeSpec:
case StoredTypeSpecWithTemplate:
return getAsType()->getAsCXXRecordDecl();
}
llvm_unreachable("Invalid NNS Kind!");
}
/// Whether this nested name specifier refers to a dependent
/// type or not.
bool NestedNameSpecifier::isDependent() const {
switch (getKind()) {
case Identifier:
// Identifier specifiers always represent dependent types
return true;
case Namespace:
case NamespaceAlias:
case Global:
return false;
case Super: {
CXXRecordDecl *RD = static_cast<CXXRecordDecl *>(Specifier);
for (const auto &Base : RD->bases())
if (Base.getType()->isDependentType())
return true;
return false;
}
case TypeSpec:
case TypeSpecWithTemplate:
return getAsType()->isDependentType();
}
llvm_unreachable("Invalid NNS Kind!");
}
/// Whether this nested name specifier refers to a dependent
/// type or not.
bool NestedNameSpecifier::isInstantiationDependent() const {
switch (getKind()) {
case Identifier:
// Identifier specifiers always represent dependent types
return true;
case Namespace:
case NamespaceAlias:
case Global:
case Super:
return false;
case TypeSpec:
case TypeSpecWithTemplate:
return getAsType()->isInstantiationDependentType();
}
llvm_unreachable("Invalid NNS Kind!");
}
bool NestedNameSpecifier::containsUnexpandedParameterPack() const {
switch (getKind()) {
case Identifier:
return getPrefix() && getPrefix()->containsUnexpandedParameterPack();
case Namespace:
case NamespaceAlias:
case Global:
case Super:
return false;
case TypeSpec:
case TypeSpecWithTemplate:
return getAsType()->containsUnexpandedParameterPack();
}
llvm_unreachable("Invalid NNS Kind!");
}
/// Print this nested name specifier to the given output
/// stream.
void NestedNameSpecifier::print(raw_ostream &OS, const PrintingPolicy &Policy,
bool ResolveTemplateArguments) const {
if (getPrefix())
getPrefix()->print(OS, Policy);
switch (getKind()) {
case Identifier:
OS << getAsIdentifier()->getName();
break;
case Namespace:
if (getAsNamespace()->isAnonymousNamespace())
return;
OS << getAsNamespace()->getName();
break;
case NamespaceAlias:
OS << getAsNamespaceAlias()->getName();
break;
case Global:
break;
case Super:
OS << "__super";
break;
case TypeSpecWithTemplate:
OS << "template ";
// Fall through to print the type.
LLVM_FALLTHROUGH;
case TypeSpec: {
const auto *Record =
dyn_cast_or_null<ClassTemplateSpecializationDecl>(getAsRecordDecl());
if (ResolveTemplateArguments && Record) {
// Print the type trait with resolved template parameters.
Record->printName(OS);
printTemplateArgumentList(OS, Record->getTemplateArgs().asArray(),
Policy);
break;
}
const Type *T = getAsType();
PrintingPolicy InnerPolicy(Policy);
InnerPolicy.SuppressScope = true;
// Nested-name-specifiers are intended to contain minimally-qualified
// types. An actual ElaboratedType will not occur, since we'll store
// just the type that is referred to in the nested-name-specifier (e.g.,
// a TypedefType, TagType, etc.). However, when we are dealing with
// dependent template-id types (e.g., Outer<T>::template Inner<U>),
// the type requires its own nested-name-specifier for uniqueness, so we
// suppress that nested-name-specifier during printing.
assert(!isa<ElaboratedType>(T) &&
"Elaborated type in nested-name-specifier");
if (const TemplateSpecializationType *SpecType
= dyn_cast<TemplateSpecializationType>(T)) {
// Print the template name without its corresponding
// nested-name-specifier.
SpecType->getTemplateName().print(OS, InnerPolicy, true);
// Print the template argument list.
printTemplateArgumentList(OS, SpecType->template_arguments(),
InnerPolicy);
} else {
// Print the type normally
QualType(T, 0).print(OS, InnerPolicy);
}
break;
}
}
OS << "::";
}
LLVM_DUMP_METHOD void NestedNameSpecifier::dump(const LangOptions &LO) const {
dump(llvm::errs(), LO);
}
LLVM_DUMP_METHOD void NestedNameSpecifier::dump() const { dump(llvm::errs()); }
LLVM_DUMP_METHOD void NestedNameSpecifier::dump(llvm::raw_ostream &OS) const {
LangOptions LO;
dump(OS, LO);
}
LLVM_DUMP_METHOD void NestedNameSpecifier::dump(llvm::raw_ostream &OS,
const LangOptions &LO) const {
print(OS, PrintingPolicy(LO));
}
unsigned
NestedNameSpecifierLoc::getLocalDataLength(NestedNameSpecifier *Qualifier) {
assert(Qualifier && "Expected a non-NULL qualifier");
// Location of the trailing '::'.
unsigned Length = sizeof(unsigned);
switch (Qualifier->getKind()) {
case NestedNameSpecifier::Global:
// Nothing more to add.
break;
case NestedNameSpecifier::Identifier:
case NestedNameSpecifier::Namespace:
case NestedNameSpecifier::NamespaceAlias:
case NestedNameSpecifier::Super:
// The location of the identifier or namespace name.
Length += sizeof(unsigned);
break;
case NestedNameSpecifier::TypeSpecWithTemplate:
case NestedNameSpecifier::TypeSpec:
// The "void*" that points at the TypeLoc data.
// Note: the 'template' keyword is part of the TypeLoc.
Length += sizeof(void *);
break;
}
return Length;
}
unsigned
NestedNameSpecifierLoc::getDataLength(NestedNameSpecifier *Qualifier) {
unsigned Length = 0;
for (; Qualifier; Qualifier = Qualifier->getPrefix())
Length += getLocalDataLength(Qualifier);
return Length;
}
/// Load a (possibly unaligned) source location from a given address
/// and offset.
static SourceLocation LoadSourceLocation(void *Data, unsigned Offset) {
unsigned Raw;
memcpy(&Raw, static_cast<char *>(Data) + Offset, sizeof(unsigned));
return SourceLocation::getFromRawEncoding(Raw);
}
/// Load a (possibly unaligned) pointer from a given address and
/// offset.
static void *LoadPointer(void *Data, unsigned Offset) {
void *Result;
memcpy(&Result, static_cast<char *>(Data) + Offset, sizeof(void*));
return Result;
}
SourceRange NestedNameSpecifierLoc::getSourceRange() const {
if (!Qualifier)
return SourceRange();
NestedNameSpecifierLoc First = *this;
while (NestedNameSpecifierLoc Prefix = First.getPrefix())
First = Prefix;
return SourceRange(First.getLocalSourceRange().getBegin(),
getLocalSourceRange().getEnd());
}
SourceRange NestedNameSpecifierLoc::getLocalSourceRange() const {
if (!Qualifier)
return SourceRange();
unsigned Offset = getDataLength(Qualifier->getPrefix());
switch (Qualifier->getKind()) {
case NestedNameSpecifier::Global:
return LoadSourceLocation(Data, Offset);
case NestedNameSpecifier::Identifier:
case NestedNameSpecifier::Namespace:
case NestedNameSpecifier::NamespaceAlias:
case NestedNameSpecifier::Super:
return SourceRange(LoadSourceLocation(Data, Offset),
LoadSourceLocation(Data, Offset + sizeof(unsigned)));
case NestedNameSpecifier::TypeSpecWithTemplate:
case NestedNameSpecifier::TypeSpec: {
// The "void*" that points at the TypeLoc data.
// Note: the 'template' keyword is part of the TypeLoc.
void *TypeData = LoadPointer(Data, Offset);
TypeLoc TL(Qualifier->getAsType(), TypeData);
return SourceRange(TL.getBeginLoc(),
LoadSourceLocation(Data, Offset + sizeof(void*)));
}
}
llvm_unreachable("Invalid NNS Kind!");
}
TypeLoc NestedNameSpecifierLoc::getTypeLoc() const {
if (Qualifier->getKind() != NestedNameSpecifier::TypeSpec &&
Qualifier->getKind() != NestedNameSpecifier::TypeSpecWithTemplate)
return TypeLoc();
// The "void*" that points at the TypeLoc data.
unsigned Offset = getDataLength(Qualifier->getPrefix());
void *TypeData = LoadPointer(Data, Offset);
return TypeLoc(Qualifier->getAsType(), TypeData);
}
static void Append(char *Start, char *End, char *&Buffer, unsigned &BufferSize,
unsigned &BufferCapacity) {
if (Start == End)
return;
if (BufferSize + (End - Start) > BufferCapacity) {
// Reallocate the buffer.
unsigned NewCapacity = std::max(
(unsigned)(BufferCapacity ? BufferCapacity * 2 : sizeof(void *) * 2),
(unsigned)(BufferSize + (End - Start)));
char *NewBuffer = static_cast<char *>(llvm::safe_malloc(NewCapacity));
if (BufferCapacity) {
memcpy(NewBuffer, Buffer, BufferSize);
free(Buffer);
}
Buffer = NewBuffer;
BufferCapacity = NewCapacity;
}
memcpy(Buffer + BufferSize, Start, End - Start);
BufferSize += End-Start;
}
/// Save a source location to the given buffer.
static void SaveSourceLocation(SourceLocation Loc, char *&Buffer,
unsigned &BufferSize, unsigned &BufferCapacity) {
unsigned Raw = Loc.getRawEncoding();
Append(reinterpret_cast<char *>(&Raw),
reinterpret_cast<char *>(&Raw) + sizeof(unsigned),
Buffer, BufferSize, BufferCapacity);
}
/// Save a pointer to the given buffer.
static void SavePointer(void *Ptr, char *&Buffer, unsigned &BufferSize,
unsigned &BufferCapacity) {
Append(reinterpret_cast<char *>(&Ptr),
reinterpret_cast<char *>(&Ptr) + sizeof(void *),
Buffer, BufferSize, BufferCapacity);
}
NestedNameSpecifierLocBuilder::
NestedNameSpecifierLocBuilder(const NestedNameSpecifierLocBuilder &Other)
: Representation(Other.Representation) {
if (!Other.Buffer)
return;
if (Other.BufferCapacity == 0) {
// Shallow copy is okay.
Buffer = Other.Buffer;
BufferSize = Other.BufferSize;
return;
}
// Deep copy
Append(Other.Buffer, Other.Buffer + Other.BufferSize, Buffer, BufferSize,
BufferCapacity);
}
NestedNameSpecifierLocBuilder &
NestedNameSpecifierLocBuilder::
operator=(const NestedNameSpecifierLocBuilder &Other) {
Representation = Other.Representation;
if (Buffer && Other.Buffer && BufferCapacity >= Other.BufferSize) {
// Re-use our storage.
BufferSize = Other.BufferSize;
memcpy(Buffer, Other.Buffer, BufferSize);
return *this;
}
// Free our storage, if we have any.
if (BufferCapacity) {
free(Buffer);
BufferCapacity = 0;
}
if (!Other.Buffer) {
// Empty.
Buffer = nullptr;
BufferSize = 0;
return *this;
}
if (Other.BufferCapacity == 0) {
// Shallow copy is okay.
Buffer = Other.Buffer;
BufferSize = Other.BufferSize;
return *this;
}
// Deep copy.
BufferSize = 0;
Append(Other.Buffer, Other.Buffer + Other.BufferSize, Buffer, BufferSize,
BufferCapacity);
return *this;
}
void NestedNameSpecifierLocBuilder::Extend(ASTContext &Context,
SourceLocation TemplateKWLoc,
TypeLoc TL,
SourceLocation ColonColonLoc) {
Representation = NestedNameSpecifier::Create(Context, Representation,
TemplateKWLoc.isValid(),
TL.getTypePtr());
// Push source-location info into the buffer.
SavePointer(TL.getOpaqueData(), Buffer, BufferSize, BufferCapacity);
SaveSourceLocation(ColonColonLoc, Buffer, BufferSize, BufferCapacity);
}
void NestedNameSpecifierLocBuilder::Extend(ASTContext &Context,
IdentifierInfo *Identifier,
SourceLocation IdentifierLoc,
SourceLocation ColonColonLoc) {
Representation = NestedNameSpecifier::Create(Context, Representation,
Identifier);
// Push source-location info into the buffer.
SaveSourceLocation(IdentifierLoc, Buffer, BufferSize, BufferCapacity);
SaveSourceLocation(ColonColonLoc, Buffer, BufferSize, BufferCapacity);
}
void NestedNameSpecifierLocBuilder::Extend(ASTContext &Context,
NamespaceDecl *Namespace,
SourceLocation NamespaceLoc,
SourceLocation ColonColonLoc) {
Representation = NestedNameSpecifier::Create(Context, Representation,
Namespace);
// Push source-location info into the buffer.
SaveSourceLocation(NamespaceLoc, Buffer, BufferSize, BufferCapacity);
SaveSourceLocation(ColonColonLoc, Buffer, BufferSize, BufferCapacity);
}
void NestedNameSpecifierLocBuilder::Extend(ASTContext &Context,
NamespaceAliasDecl *Alias,
SourceLocation AliasLoc,
SourceLocation ColonColonLoc) {
Representation = NestedNameSpecifier::Create(Context, Representation, Alias);
// Push source-location info into the buffer.
SaveSourceLocation(AliasLoc, Buffer, BufferSize, BufferCapacity);
SaveSourceLocation(ColonColonLoc, Buffer, BufferSize, BufferCapacity);
}
void NestedNameSpecifierLocBuilder::MakeGlobal(ASTContext &Context,
SourceLocation ColonColonLoc) {
assert(!Representation && "Already have a nested-name-specifier!?");
Representation = NestedNameSpecifier::GlobalSpecifier(Context);
// Push source-location info into the buffer.
SaveSourceLocation(ColonColonLoc, Buffer, BufferSize, BufferCapacity);
}
void NestedNameSpecifierLocBuilder::MakeSuper(ASTContext &Context,
CXXRecordDecl *RD,
SourceLocation SuperLoc,
SourceLocation ColonColonLoc) {
Representation = NestedNameSpecifier::SuperSpecifier(Context, RD);
// Push source-location info into the buffer.
SaveSourceLocation(SuperLoc, Buffer, BufferSize, BufferCapacity);
SaveSourceLocation(ColonColonLoc, Buffer, BufferSize, BufferCapacity);
}
void NestedNameSpecifierLocBuilder::MakeTrivial(ASTContext &Context,
NestedNameSpecifier *Qualifier,
SourceRange R) {
Representation = Qualifier;
// Construct bogus (but well-formed) source information for the
// nested-name-specifier.
BufferSize = 0;
SmallVector<NestedNameSpecifier *, 4> Stack;
for (NestedNameSpecifier *NNS = Qualifier; NNS; NNS = NNS->getPrefix())
Stack.push_back(NNS);
while (!Stack.empty()) {
NestedNameSpecifier *NNS = Stack.pop_back_val();
switch (NNS->getKind()) {
case NestedNameSpecifier::Identifier:
case NestedNameSpecifier::Namespace:
case NestedNameSpecifier::NamespaceAlias:
SaveSourceLocation(R.getBegin(), Buffer, BufferSize, BufferCapacity);
break;
case NestedNameSpecifier::TypeSpec:
case NestedNameSpecifier::TypeSpecWithTemplate: {
TypeSourceInfo *TSInfo
= Context.getTrivialTypeSourceInfo(QualType(NNS->getAsType(), 0),
R.getBegin());
SavePointer(TSInfo->getTypeLoc().getOpaqueData(), Buffer, BufferSize,
BufferCapacity);
break;
}
case NestedNameSpecifier::Global:
case NestedNameSpecifier::Super:
break;
}
// Save the location of the '::'.
SaveSourceLocation(Stack.empty()? R.getEnd() : R.getBegin(),
Buffer, BufferSize, BufferCapacity);
}
}
void NestedNameSpecifierLocBuilder::Adopt(NestedNameSpecifierLoc Other) {
if (BufferCapacity)
free(Buffer);
if (!Other) {
Representation = nullptr;
BufferSize = 0;
return;
}
// Rather than copying the data (which is wasteful), "adopt" the
// pointer (which points into the ASTContext) but set the capacity to zero to
// indicate that we don't own it.
Representation = Other.getNestedNameSpecifier();
Buffer = static_cast<char *>(Other.getOpaqueData());
BufferSize = Other.getDataLength();
BufferCapacity = 0;
}
NestedNameSpecifierLoc
NestedNameSpecifierLocBuilder::getWithLocInContext(ASTContext &Context) const {
if (!Representation)
return NestedNameSpecifierLoc();
// If we adopted our data pointer from elsewhere in the AST context, there's
// no need to copy the memory.
if (BufferCapacity == 0)
return NestedNameSpecifierLoc(Representation, Buffer);
// FIXME: After copying the source-location information, should we free
// our (temporary) buffer and adopt the ASTContext-allocated memory?
// Doing so would optimize repeated calls to getWithLocInContext().
void *Mem = Context.Allocate(BufferSize, alignof(void *));
memcpy(Mem, Buffer, BufferSize);
return NestedNameSpecifierLoc(Representation, Mem);
}