//===- NestedNameSpecifier.h - C++ nested name specifiers -------*- C++ -*-===//
//
// 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.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_AST_NESTEDNAMESPECIFIER_H
#define LLVM_CLANG_AST_NESTEDNAMESPECIFIER_H
#include "clang/AST/DependenceFlags.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/SourceLocation.h"
#include "llvm/ADT/DenseMapInfo.h"
#include "llvm/ADT/FoldingSet.h"
#include "llvm/ADT/PointerIntPair.h"
#include "llvm/Support/Compiler.h"
#include <cstdint>
#include <cstdlib>
#include <utility>
namespace clang {
class ASTContext;
class CXXRecordDecl;
class IdentifierInfo;
class LangOptions;
class NamespaceAliasDecl;
class NamespaceDecl;
struct PrintingPolicy;
class Type;
class TypeLoc;
/// Represents a C++ nested name specifier, such as
/// "\::std::vector<int>::".
///
/// C++ nested name specifiers are the prefixes to qualified
/// names. For example, "foo::" in "foo::x" is a nested name
/// specifier. Nested name specifiers are made up of a sequence of
/// specifiers, each of which can be a namespace, type, identifier
/// (for dependent names), decltype specifier, or the global specifier ('::').
/// The last two specifiers can only appear at the start of a
/// nested-namespace-specifier.
class NestedNameSpecifier : public llvm::FoldingSetNode {
/// Enumeration describing
enum StoredSpecifierKind {
StoredIdentifier = 0,
StoredDecl = 1,
StoredTypeSpec = 2,
StoredTypeSpecWithTemplate = 3
};
/// The nested name specifier that precedes this nested name
/// specifier.
///
/// The pointer is the nested-name-specifier that precedes this
/// one. The integer stores one of the first four values of type
/// SpecifierKind.
llvm::PointerIntPair<NestedNameSpecifier *, 2, StoredSpecifierKind> Prefix;
/// The last component in the nested name specifier, which
/// can be an identifier, a declaration, or a type.
///
/// When the pointer is NULL, this specifier represents the global
/// specifier '::'. Otherwise, the pointer is one of
/// IdentifierInfo*, Namespace*, or Type*, depending on the kind of
/// specifier as encoded within the prefix.
void* Specifier = nullptr;
public:
/// The kind of specifier that completes this nested name
/// specifier.
enum SpecifierKind {
/// An identifier, stored as an IdentifierInfo*.
Identifier,
/// A namespace, stored as a NamespaceDecl*.
Namespace,
/// A namespace alias, stored as a NamespaceAliasDecl*.
NamespaceAlias,
/// A type, stored as a Type*.
TypeSpec,
/// A type that was preceded by the 'template' keyword,
/// stored as a Type*.
TypeSpecWithTemplate,
/// The global specifier '::'. There is no stored value.
Global,
/// Microsoft's '__super' specifier, stored as a CXXRecordDecl* of
/// the class it appeared in.
Super
};
private:
/// Builds the global specifier.
NestedNameSpecifier() : Prefix(nullptr, StoredIdentifier) {}
/// Copy constructor used internally to clone nested name
/// specifiers.
NestedNameSpecifier(const NestedNameSpecifier &Other) = default;
/// Either find or insert the given nested name specifier
/// mockup in the given context.
static NestedNameSpecifier *FindOrInsert(const ASTContext &Context,
const NestedNameSpecifier &Mockup);
public:
NestedNameSpecifier &operator=(const NestedNameSpecifier &) = delete;
/// Builds a specifier combining a prefix and an identifier.
///
/// The prefix must be dependent, since nested name specifiers
/// referencing an identifier are only permitted when the identifier
/// cannot be resolved.
static NestedNameSpecifier *Create(const ASTContext &Context,
NestedNameSpecifier *Prefix,
IdentifierInfo *II);
/// Builds a nested name specifier that names a namespace.
static NestedNameSpecifier *Create(const ASTContext &Context,
NestedNameSpecifier *Prefix,
const NamespaceDecl *NS);
/// Builds a nested name specifier that names a namespace alias.
static NestedNameSpecifier *Create(const ASTContext &Context,
NestedNameSpecifier *Prefix,
NamespaceAliasDecl *Alias);
/// Builds a nested name specifier that names a type.
static NestedNameSpecifier *Create(const ASTContext &Context,
NestedNameSpecifier *Prefix,
bool Template, const Type *T);
/// Builds a specifier that consists of just an identifier.
///
/// The nested-name-specifier is assumed to be dependent, but has no
/// prefix because the prefix is implied by something outside of the
/// nested name specifier, e.g., in "x->Base::f", the "x" has a dependent
/// type.
static NestedNameSpecifier *Create(const ASTContext &Context,
IdentifierInfo *II);
/// Returns the nested name specifier representing the global
/// scope.
static NestedNameSpecifier *GlobalSpecifier(const ASTContext &Context);
/// Returns the nested name specifier representing the __super scope
/// for the given CXXRecordDecl.
static NestedNameSpecifier *SuperSpecifier(const ASTContext &Context,
CXXRecordDecl *RD);
/// Return the prefix of this nested name specifier.
///
/// The prefix contains all of the parts of the nested name
/// specifier that precede this current specifier. For example, for a
/// nested name specifier that represents "foo::bar::", the current
/// specifier will contain "bar::" and the prefix will contain
/// "foo::".
NestedNameSpecifier *getPrefix() const { return Prefix.getPointer(); }
/// Determine what kind of nested name specifier is stored.
SpecifierKind getKind() const;
/// Retrieve the identifier stored in this nested name
/// specifier.
IdentifierInfo *getAsIdentifier() const {
if (Prefix.getInt() == StoredIdentifier)
return (IdentifierInfo *)Specifier;
return nullptr;
}
/// Retrieve the namespace stored in this nested name
/// specifier.
NamespaceDecl *getAsNamespace() const;
/// Retrieve the namespace alias stored in this nested name
/// specifier.
NamespaceAliasDecl *getAsNamespaceAlias() const;
/// Retrieve the record declaration stored in this nested name
/// specifier.
CXXRecordDecl *getAsRecordDecl() const;
/// Retrieve the type stored in this nested name specifier.
const Type *getAsType() const {
if (Prefix.getInt() == StoredTypeSpec ||
Prefix.getInt() == StoredTypeSpecWithTemplate)
return (const Type *)Specifier;
return nullptr;
}
NestedNameSpecifierDependence getDependence() const;
/// Whether this nested name specifier refers to a dependent
/// type or not.
bool isDependent() const;
/// Whether this nested name specifier involves a template
/// parameter.
bool isInstantiationDependent() const;
/// Whether this nested-name-specifier contains an unexpanded
/// parameter pack (for C++11 variadic templates).
bool containsUnexpandedParameterPack() const;
/// Whether this nested name specifier contains an error.
bool containsErrors() const;
/// Print this nested name specifier to the given output stream. If
/// `ResolveTemplateArguments` is true, we'll print actual types, e.g.
/// `ns::SomeTemplate<int, MyClass>` instead of
/// `ns::SomeTemplate<Container::value_type, T>`.
void print(raw_ostream &OS, const PrintingPolicy &Policy,
bool ResolveTemplateArguments = false) const;
void Profile(llvm::FoldingSetNodeID &ID) const {
ID.AddPointer(Prefix.getOpaqueValue());
ID.AddPointer(Specifier);
}
/// Dump the nested name specifier to standard output to aid
/// in debugging.
void dump(const LangOptions &LO) const;
void dump() const;
void dump(llvm::raw_ostream &OS) const;
void dump(llvm::raw_ostream &OS, const LangOptions &LO) const;
};
/// A C++ nested-name-specifier augmented with source location
/// information.
class NestedNameSpecifierLoc {
NestedNameSpecifier *Qualifier = nullptr;
void *Data = nullptr;
/// Determines the data length for the last component in the
/// given nested-name-specifier.
static unsigned getLocalDataLength(NestedNameSpecifier *Qualifier);
/// Determines the data length for the entire
/// nested-name-specifier.
static unsigned getDataLength(NestedNameSpecifier *Qualifier);
public:
/// Construct an empty nested-name-specifier.
NestedNameSpecifierLoc() = default;
/// Construct a nested-name-specifier with source location information
/// from
NestedNameSpecifierLoc(NestedNameSpecifier *Qualifier, void *Data)
: Qualifier(Qualifier), Data(Data) {}
/// Evaluates true when this nested-name-specifier location is
/// non-empty.
explicit operator bool() const { return Qualifier; }
/// Evaluates true when this nested-name-specifier location is
/// empty.
bool hasQualifier() const { return Qualifier; }
/// Retrieve the nested-name-specifier to which this instance
/// refers.
NestedNameSpecifier *getNestedNameSpecifier() const {
return Qualifier;
}
/// Retrieve the opaque pointer that refers to source-location data.
void *getOpaqueData() const { return Data; }
/// Retrieve the source range covering the entirety of this
/// nested-name-specifier.
///
/// For example, if this instance refers to a nested-name-specifier
/// \c \::std::vector<int>::, the returned source range would cover
/// from the initial '::' to the last '::'.
SourceRange getSourceRange() const LLVM_READONLY;
/// Retrieve the source range covering just the last part of
/// this nested-name-specifier, not including the prefix.
///
/// For example, if this instance refers to a nested-name-specifier
/// \c \::std::vector<int>::, the returned source range would cover
/// from "vector" to the last '::'.
SourceRange getLocalSourceRange() const;
/// Retrieve the location of the beginning of this
/// nested-name-specifier.
SourceLocation getBeginLoc() const {
return getSourceRange().getBegin();
}
/// Retrieve the location of the end of this
/// nested-name-specifier.
SourceLocation getEndLoc() const {
return getSourceRange().getEnd();
}
/// Retrieve the location of the beginning of this
/// component of the nested-name-specifier.
SourceLocation getLocalBeginLoc() const {
return getLocalSourceRange().getBegin();
}
/// Retrieve the location of the end of this component of the
/// nested-name-specifier.
SourceLocation getLocalEndLoc() const {
return getLocalSourceRange().getEnd();
}
/// Return the prefix of this nested-name-specifier.
///
/// For example, if this instance refers to a nested-name-specifier
/// \c \::std::vector<int>::, the prefix is \c \::std::. Note that the
/// returned prefix may be empty, if this is the first component of
/// the nested-name-specifier.
NestedNameSpecifierLoc getPrefix() const {
if (!Qualifier)
return *this;
return NestedNameSpecifierLoc(Qualifier->getPrefix(), Data);
}
/// For a nested-name-specifier that refers to a type,
/// retrieve the type with source-location information.
TypeLoc getTypeLoc() const;
/// Determines the data length for the entire
/// nested-name-specifier.
unsigned getDataLength() const { return getDataLength(Qualifier); }
friend bool operator==(NestedNameSpecifierLoc X,
NestedNameSpecifierLoc Y) {
return X.Qualifier == Y.Qualifier && X.Data == Y.Data;
}
friend bool operator!=(NestedNameSpecifierLoc X,
NestedNameSpecifierLoc Y) {
return !(X == Y);
}
};
/// Class that aids in the construction of nested-name-specifiers along
/// with source-location information for all of the components of the
/// nested-name-specifier.
class NestedNameSpecifierLocBuilder {
/// The current representation of the nested-name-specifier we're
/// building.
NestedNameSpecifier *Representation = nullptr;
/// Buffer used to store source-location information for the
/// nested-name-specifier.
///
/// Note that we explicitly manage the buffer (rather than using a
/// SmallVector) because \c Declarator expects it to be possible to memcpy()
/// a \c CXXScopeSpec, and CXXScopeSpec uses a NestedNameSpecifierLocBuilder.
char *Buffer = nullptr;
/// The size of the buffer used to store source-location information
/// for the nested-name-specifier.
unsigned BufferSize = 0;
/// The capacity of the buffer used to store source-location
/// information for the nested-name-specifier.
unsigned BufferCapacity = 0;
public:
NestedNameSpecifierLocBuilder() = default;
NestedNameSpecifierLocBuilder(const NestedNameSpecifierLocBuilder &Other);
NestedNameSpecifierLocBuilder &
operator=(const NestedNameSpecifierLocBuilder &Other);
~NestedNameSpecifierLocBuilder() {
if (BufferCapacity)
free(Buffer);
}
/// Retrieve the representation of the nested-name-specifier.
NestedNameSpecifier *getRepresentation() const { return Representation; }
/// Extend the current nested-name-specifier by another
/// nested-name-specifier component of the form 'type::'.
///
/// \param Context The AST context in which this nested-name-specifier
/// resides.
///
/// \param TemplateKWLoc The location of the 'template' keyword, if present.
///
/// \param TL The TypeLoc that describes the type preceding the '::'.
///
/// \param ColonColonLoc The location of the trailing '::'.
void Extend(ASTContext &Context, SourceLocation TemplateKWLoc, TypeLoc TL,
SourceLocation ColonColonLoc);
/// Extend the current nested-name-specifier by another
/// nested-name-specifier component of the form 'identifier::'.
///
/// \param Context The AST context in which this nested-name-specifier
/// resides.
///
/// \param Identifier The identifier.
///
/// \param IdentifierLoc The location of the identifier.
///
/// \param ColonColonLoc The location of the trailing '::'.
void Extend(ASTContext &Context, IdentifierInfo *Identifier,
SourceLocation IdentifierLoc, SourceLocation ColonColonLoc);
/// Extend the current nested-name-specifier by another
/// nested-name-specifier component of the form 'namespace::'.
///
/// \param Context The AST context in which this nested-name-specifier
/// resides.
///
/// \param Namespace The namespace.
///
/// \param NamespaceLoc The location of the namespace name.
///
/// \param ColonColonLoc The location of the trailing '::'.
void Extend(ASTContext &Context, NamespaceDecl *Namespace,
SourceLocation NamespaceLoc, SourceLocation ColonColonLoc);
/// Extend the current nested-name-specifier by another
/// nested-name-specifier component of the form 'namespace-alias::'.
///
/// \param Context The AST context in which this nested-name-specifier
/// resides.
///
/// \param Alias The namespace alias.
///
/// \param AliasLoc The location of the namespace alias
/// name.
///
/// \param ColonColonLoc The location of the trailing '::'.
void Extend(ASTContext &Context, NamespaceAliasDecl *Alias,
SourceLocation AliasLoc, SourceLocation ColonColonLoc);
/// Turn this (empty) nested-name-specifier into the global
/// nested-name-specifier '::'.
void MakeGlobal(ASTContext &Context, SourceLocation ColonColonLoc);
/// Turns this (empty) nested-name-specifier into '__super'
/// nested-name-specifier.
///
/// \param Context The AST context in which this nested-name-specifier
/// resides.
///
/// \param RD The declaration of the class in which nested-name-specifier
/// appeared.
///
/// \param SuperLoc The location of the '__super' keyword.
/// name.
///
/// \param ColonColonLoc The location of the trailing '::'.
void MakeSuper(ASTContext &Context, CXXRecordDecl *RD,
SourceLocation SuperLoc, SourceLocation ColonColonLoc);
/// Make a new nested-name-specifier from incomplete source-location
/// information.
///
/// This routine should be used very, very rarely, in cases where we
/// need to synthesize a nested-name-specifier. Most code should instead use
/// \c Adopt() with a proper \c NestedNameSpecifierLoc.
void MakeTrivial(ASTContext &Context, NestedNameSpecifier *Qualifier,
SourceRange R);
/// Adopt an existing nested-name-specifier (with source-range
/// information).
void Adopt(NestedNameSpecifierLoc Other);
/// Retrieve the source range covered by this nested-name-specifier.
SourceRange getSourceRange() const LLVM_READONLY {
return NestedNameSpecifierLoc(Representation, Buffer).getSourceRange();
}
/// Retrieve a nested-name-specifier with location information,
/// copied into the given AST context.
///
/// \param Context The context into which this nested-name-specifier will be
/// copied.
NestedNameSpecifierLoc getWithLocInContext(ASTContext &Context) const;
/// Retrieve a nested-name-specifier with location
/// information based on the information in this builder.
///
/// This loc will contain references to the builder's internal data and may
/// be invalidated by any change to the builder.
NestedNameSpecifierLoc getTemporary() const {
return NestedNameSpecifierLoc(Representation, Buffer);
}
/// Clear out this builder, and prepare it to build another
/// nested-name-specifier with source-location information.
void Clear() {
Representation = nullptr;
BufferSize = 0;
}
/// Retrieve the underlying buffer.
///
/// \returns A pair containing a pointer to the buffer of source-location
/// data and the size of the source-location data that resides in that
/// buffer.
std::pair<char *, unsigned> getBuffer() const {
return std::make_pair(Buffer, BufferSize);
}
};
/// Insertion operator for diagnostics. This allows sending
/// NestedNameSpecifiers into a diagnostic with <<.
inline const StreamingDiagnostic &operator<<(const StreamingDiagnostic &DB,
NestedNameSpecifier *NNS) {
DB.AddTaggedVal(reinterpret_cast<uint64_t>(NNS),
DiagnosticsEngine::ak_nestednamespec);
return DB;
}
} // namespace clang
namespace llvm {
template <> struct DenseMapInfo<clang::NestedNameSpecifierLoc> {
using FirstInfo = DenseMapInfo<clang::NestedNameSpecifier *>;
using SecondInfo = DenseMapInfo<void *>;
static clang::NestedNameSpecifierLoc getEmptyKey() {
return clang::NestedNameSpecifierLoc(FirstInfo::getEmptyKey(),
SecondInfo::getEmptyKey());
}
static clang::NestedNameSpecifierLoc getTombstoneKey() {
return clang::NestedNameSpecifierLoc(FirstInfo::getTombstoneKey(),
SecondInfo::getTombstoneKey());
}
static unsigned getHashValue(const clang::NestedNameSpecifierLoc &PairVal) {
return hash_combine(
FirstInfo::getHashValue(PairVal.getNestedNameSpecifier()),
SecondInfo::getHashValue(PairVal.getOpaqueData()));
}
static bool isEqual(const clang::NestedNameSpecifierLoc &LHS,
const clang::NestedNameSpecifierLoc &RHS) {
return LHS == RHS;
}
};
} // namespace llvm
#endif // LLVM_CLANG_AST_NESTEDNAMESPECIFIER_H