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//===- IdentifierTable.h - Hash table for identifier lookup -----*- C++ -*-===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
/// \file
/// Defines the clang::IdentifierInfo, clang::IdentifierTable, and
/// clang::Selector interfaces.
#include "clang/Basic/LLVM.h"
#include "clang/Basic/TokenKinds.h"
#include "llvm/ADT/DenseMapInfo.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Allocator.h"
#include "llvm/Support/PointerLikeTypeTraits.h"
#include "llvm/Support/type_traits.h"
#include <cassert>
#include <cstddef>
#include <cstdint>
#include <cstring>
#include <string>
#include <utility>
namespace clang {
class DeclarationName;
class DeclarationNameTable;
class IdentifierInfo;
class LangOptions;
class MultiKeywordSelector;
class SourceLocation;
/// A simple pair of identifier info and location.
using IdentifierLocPair = std::pair<IdentifierInfo *, SourceLocation>;
/// IdentifierInfo and other related classes are aligned to
/// 8 bytes so that DeclarationName can use the lower 3 bits
/// of a pointer to one of these classes.
enum { IdentifierInfoAlignment = 8 };
/// One of these records is kept for each identifier that
/// is lexed. This contains information about whether the token was \#define'd,
/// is a language keyword, or if it is a front-end token of some sort (e.g. a
/// variable or function name). The preprocessor keeps this information in a
/// set, and all tok::identifier tokens have a pointer to one of these.
/// It is aligned to 8 bytes because DeclarationName needs the lower 3 bits.
class alignas(IdentifierInfoAlignment) IdentifierInfo {
friend class IdentifierTable;
// Front-end token ID or tok::identifier.
unsigned TokenID : 9;
// ObjC keyword ('protocol' in '@protocol') or builtin (__builtin_inf).
// First NUM_OBJC_KEYWORDS values are for Objective-C,
// the remaining values are for builtins.
unsigned ObjCOrBuiltinID : 13;
// True if there is a #define for this.
unsigned HasMacro : 1;
// True if there was a #define for this.
unsigned HadMacro : 1;
// True if the identifier is a language extension.
unsigned IsExtension : 1;
// True if the identifier is a keyword in a newer or proposed Standard.
unsigned IsFutureCompatKeyword : 1;
// True if the identifier is poisoned.
unsigned IsPoisoned : 1;
// True if the identifier is a C++ operator keyword.
unsigned IsCPPOperatorKeyword : 1;
// Internal bit set by the member function RecomputeNeedsHandleIdentifier.
// See comment about RecomputeNeedsHandleIdentifier for more info.
unsigned NeedsHandleIdentifier : 1;
// True if the identifier was loaded (at least partially) from an AST file.
unsigned IsFromAST : 1;
// True if the identifier has changed from the definition
// loaded from an AST file.
unsigned ChangedAfterLoad : 1;
// True if the identifier's frontend information has changed from the
// definition loaded from an AST file.
unsigned FEChangedAfterLoad : 1;
// True if revertTokenIDToIdentifier was called.
unsigned RevertedTokenID : 1;
// True if there may be additional information about
// this identifier stored externally.
unsigned OutOfDate : 1;
// True if this is the 'import' contextual keyword.
unsigned IsModulesImport : 1;
// 29 bits left in a 64-bit word.
// Managed by the language front-end.
void *FETokenInfo = nullptr;
llvm::StringMapEntry<IdentifierInfo *> *Entry = nullptr;
: TokenID(tok::identifier), ObjCOrBuiltinID(0), HasMacro(false),
HadMacro(false), IsExtension(false), IsFutureCompatKeyword(false),
IsPoisoned(false), IsCPPOperatorKeyword(false),
NeedsHandleIdentifier(false), IsFromAST(false), ChangedAfterLoad(false),
FEChangedAfterLoad(false), RevertedTokenID(false), OutOfDate(false),
IsModulesImport(false) {}
IdentifierInfo(const IdentifierInfo &) = delete;
IdentifierInfo &operator=(const IdentifierInfo &) = delete;
IdentifierInfo(IdentifierInfo &&) = delete;
IdentifierInfo &operator=(IdentifierInfo &&) = delete;
/// Return true if this is the identifier for the specified string.
/// This is intended to be used for string literals only: II->isStr("foo").
template <std::size_t StrLen>
bool isStr(const char (&Str)[StrLen]) const {
return getLength() == StrLen-1 &&
memcmp(getNameStart(), Str, StrLen-1) == 0;
/// Return true if this is the identifier for the specified StringRef.
bool isStr(llvm::StringRef Str) const {
llvm::StringRef ThisStr(getNameStart(), getLength());
return ThisStr == Str;
/// Return the beginning of the actual null-terminated string for this
/// identifier.
const char *getNameStart() const { return Entry->getKeyData(); }
/// Efficiently return the length of this identifier info.
unsigned getLength() const { return Entry->getKeyLength(); }
/// Return the actual identifier string.
StringRef getName() const {
return StringRef(getNameStart(), getLength());
/// Return true if this identifier is \#defined to some other value.
/// \note The current definition may be in a module and not currently visible.
bool hasMacroDefinition() const {
return HasMacro;
void setHasMacroDefinition(bool Val) {
if (HasMacro == Val) return;
HasMacro = Val;
if (Val) {
NeedsHandleIdentifier = true;
HadMacro = true;
} else {
/// Returns true if this identifier was \#defined to some value at any
/// moment. In this case there should be an entry for the identifier in the
/// macro history table in Preprocessor.
bool hadMacroDefinition() const {
return HadMacro;
/// If this is a source-language token (e.g. 'for'), this API
/// can be used to cause the lexer to map identifiers to source-language
/// tokens.
tok::TokenKind getTokenID() const { return (tok::TokenKind)TokenID; }
/// True if revertTokenIDToIdentifier() was called.
bool hasRevertedTokenIDToIdentifier() const { return RevertedTokenID; }
/// Revert TokenID to tok::identifier; used for GNU libstdc++ 4.2
/// compatibility.
/// TokenID is normally read-only but there are 2 instances where we revert it
/// to tok::identifier for libstdc++ 4.2. Keep track of when this happens
/// using this method so we can inform serialization about it.
void revertTokenIDToIdentifier() {
assert(TokenID != tok::identifier && "Already at tok::identifier");
TokenID = tok::identifier;
RevertedTokenID = true;
void revertIdentifierToTokenID(tok::TokenKind TK) {
assert(TokenID == tok::identifier && "Should be at tok::identifier");
TokenID = TK;
RevertedTokenID = false;
/// Return the preprocessor keyword ID for this identifier.
/// For example, "define" will return tok::pp_define.
tok::PPKeywordKind getPPKeywordID() const;
/// Return the Objective-C keyword ID for the this identifier.
/// For example, 'class' will return tok::objc_class if ObjC is enabled.
tok::ObjCKeywordKind getObjCKeywordID() const {
if (ObjCOrBuiltinID < tok::NUM_OBJC_KEYWORDS)
return tok::ObjCKeywordKind(ObjCOrBuiltinID);
return tok::objc_not_keyword;
void setObjCKeywordID(tok::ObjCKeywordKind ID) { ObjCOrBuiltinID = ID; }
/// True if setNotBuiltin() was called.
bool hasRevertedBuiltin() const {
return ObjCOrBuiltinID == tok::NUM_OBJC_KEYWORDS;
/// Revert the identifier to a non-builtin identifier. We do this if
/// the name of a known builtin library function is used to declare that
/// function, but an unexpected type is specified.
void revertBuiltin() {
/// Return a value indicating whether this is a builtin function.
/// 0 is not-built-in. 1+ are specific builtin functions.
unsigned getBuiltinID() const {
if (ObjCOrBuiltinID >= tok::NUM_OBJC_KEYWORDS)
return ObjCOrBuiltinID - tok::NUM_OBJC_KEYWORDS;
return 0;
void setBuiltinID(unsigned ID) {
ObjCOrBuiltinID = ID + tok::NUM_OBJC_KEYWORDS;
assert(ObjCOrBuiltinID - unsigned(tok::NUM_OBJC_KEYWORDS) == ID
&& "ID too large for field!");
unsigned getObjCOrBuiltinID() const { return ObjCOrBuiltinID; }
void setObjCOrBuiltinID(unsigned ID) { ObjCOrBuiltinID = ID; }
/// get/setExtension - Initialize information about whether or not this
/// language token is an extension. This controls extension warnings, and is
/// only valid if a custom token ID is set.
bool isExtensionToken() const { return IsExtension; }
void setIsExtensionToken(bool Val) {
IsExtension = Val;
if (Val)
NeedsHandleIdentifier = true;
/// is/setIsFutureCompatKeyword - Initialize information about whether or not
/// this language token is a keyword in a newer or proposed Standard. This
/// controls compatibility warnings, and is only true when not parsing the
/// corresponding Standard. Once a compatibility problem has been diagnosed
/// with this keyword, the flag will be cleared.
bool isFutureCompatKeyword() const { return IsFutureCompatKeyword; }
void setIsFutureCompatKeyword(bool Val) {
IsFutureCompatKeyword = Val;
if (Val)
NeedsHandleIdentifier = true;
/// setIsPoisoned - Mark this identifier as poisoned. After poisoning, the
/// Preprocessor will emit an error every time this token is used.
void setIsPoisoned(bool Value = true) {
IsPoisoned = Value;
if (Value)
NeedsHandleIdentifier = true;
/// Return true if this token has been poisoned.
bool isPoisoned() const { return IsPoisoned; }
/// isCPlusPlusOperatorKeyword/setIsCPlusPlusOperatorKeyword controls whether
/// this identifier is a C++ alternate representation of an operator.
void setIsCPlusPlusOperatorKeyword(bool Val = true) {
IsCPPOperatorKeyword = Val;
bool isCPlusPlusOperatorKeyword() const { return IsCPPOperatorKeyword; }
/// Return true if this token is a keyword in the specified language.
bool isKeyword(const LangOptions &LangOpts) const;
/// Return true if this token is a C++ keyword in the specified
/// language.
bool isCPlusPlusKeyword(const LangOptions &LangOpts) const;
/// Get and set FETokenInfo. The language front-end is allowed to associate
/// arbitrary metadata with this token.
void *getFETokenInfo() const { return FETokenInfo; }
void setFETokenInfo(void *T) { FETokenInfo = T; }
/// Return true if the Preprocessor::HandleIdentifier must be called
/// on a token of this identifier.
/// If this returns false, we know that HandleIdentifier will not affect
/// the token.
bool isHandleIdentifierCase() const { return NeedsHandleIdentifier; }
/// Return true if the identifier in its current state was loaded
/// from an AST file.
bool isFromAST() const { return IsFromAST; }
void setIsFromAST() { IsFromAST = true; }
/// Determine whether this identifier has changed since it was loaded
/// from an AST file.
bool hasChangedSinceDeserialization() const {
return ChangedAfterLoad;
/// Note that this identifier has changed since it was loaded from
/// an AST file.
void setChangedSinceDeserialization() {
ChangedAfterLoad = true;
/// Determine whether the frontend token information for this
/// identifier has changed since it was loaded from an AST file.
bool hasFETokenInfoChangedSinceDeserialization() const {
return FEChangedAfterLoad;
/// Note that the frontend token information for this identifier has
/// changed since it was loaded from an AST file.
void setFETokenInfoChangedSinceDeserialization() {
FEChangedAfterLoad = true;
/// Determine whether the information for this identifier is out of
/// date with respect to the external source.
bool isOutOfDate() const { return OutOfDate; }
/// Set whether the information for this identifier is out of
/// date with respect to the external source.
void setOutOfDate(bool OOD) {
OutOfDate = OOD;
if (OOD)
NeedsHandleIdentifier = true;
/// Determine whether this is the contextual keyword \c import.
bool isModulesImport() const { return IsModulesImport; }
/// Set whether this identifier is the contextual keyword \c import.
void setModulesImport(bool I) {
IsModulesImport = I;
if (I)
NeedsHandleIdentifier = true;
/// Return true if this identifier is an editor placeholder.
/// Editor placeholders are produced by the code-completion engine and are
/// represented as characters between '<#' and '#>' in the source code. An
/// example of auto-completed call with a placeholder parameter is shown
/// below:
/// \code
/// function(<#int x#>);
/// \endcode
bool isEditorPlaceholder() const {
return getName().startswith("<#") && getName().endswith("#>");
/// Provide less than operator for lexicographical sorting.
bool operator<(const IdentifierInfo &RHS) const {
return getName() < RHS.getName();
/// The Preprocessor::HandleIdentifier does several special (but rare)
/// things to identifiers of various sorts. For example, it changes the
/// \c for keyword token from tok::identifier to tok::for.
/// This method is very tied to the definition of HandleIdentifier. Any
/// change to it should be reflected here.
void RecomputeNeedsHandleIdentifier() {
NeedsHandleIdentifier = isPoisoned() || hasMacroDefinition() ||
isExtensionToken() || isFutureCompatKeyword() ||
isOutOfDate() || isModulesImport();
/// An RAII object for [un]poisoning an identifier within a scope.
/// \p II is allowed to be null, in which case objects of this type have
/// no effect.
class PoisonIdentifierRAIIObject {
IdentifierInfo *const II;
const bool OldValue;
PoisonIdentifierRAIIObject(IdentifierInfo *II, bool NewValue)
: II(II), OldValue(II ? II->isPoisoned() : false) {
~PoisonIdentifierRAIIObject() {
/// An iterator that walks over all of the known identifiers
/// in the lookup table.
/// Since this iterator uses an abstract interface via virtual
/// functions, it uses an object-oriented interface rather than the
/// more standard C++ STL iterator interface. In this OO-style
/// iteration, the single function \c Next() provides dereference,
/// advance, and end-of-sequence checking in a single
/// operation. Subclasses of this iterator type will provide the
/// actual functionality.
class IdentifierIterator {
IdentifierIterator() = default;
IdentifierIterator(const IdentifierIterator &) = delete;
IdentifierIterator &operator=(const IdentifierIterator &) = delete;
virtual ~IdentifierIterator();
/// Retrieve the next string in the identifier table and
/// advances the iterator for the following string.
/// \returns The next string in the identifier table. If there is
/// no such string, returns an empty \c StringRef.
virtual StringRef Next() = 0;
/// Provides lookups to, and iteration over, IdentiferInfo objects.
class IdentifierInfoLookup {
virtual ~IdentifierInfoLookup();
/// Return the IdentifierInfo for the specified named identifier.
/// Unlike the version in IdentifierTable, this returns a pointer instead
/// of a reference. If the pointer is null then the IdentifierInfo cannot
/// be found.
virtual IdentifierInfo* get(StringRef Name) = 0;
/// Retrieve an iterator into the set of all identifiers
/// known to this identifier lookup source.
/// This routine provides access to all of the identifiers known to
/// the identifier lookup, allowing access to the contents of the
/// identifiers without introducing the overhead of constructing
/// IdentifierInfo objects for each.
/// \returns A new iterator into the set of known identifiers. The
/// caller is responsible for deleting this iterator.
virtual IdentifierIterator *getIdentifiers();
/// Implements an efficient mapping from strings to IdentifierInfo nodes.
/// This has no other purpose, but this is an extremely performance-critical
/// piece of the code, as each occurrence of every identifier goes through
/// here when lexed.
class IdentifierTable {
// Shark shows that using MallocAllocator is *much* slower than using this
// BumpPtrAllocator!
using HashTableTy = llvm::StringMap<IdentifierInfo *, llvm::BumpPtrAllocator>;
HashTableTy HashTable;
IdentifierInfoLookup* ExternalLookup;
/// Create the identifier table.
explicit IdentifierTable(IdentifierInfoLookup *ExternalLookup = nullptr);
/// Create the identifier table, populating it with info about the
/// language keywords for the language specified by \p LangOpts.
explicit IdentifierTable(const LangOptions &LangOpts,
IdentifierInfoLookup *ExternalLookup = nullptr);
/// Set the external identifier lookup mechanism.
void setExternalIdentifierLookup(IdentifierInfoLookup *IILookup) {
ExternalLookup = IILookup;
/// Retrieve the external identifier lookup object, if any.
IdentifierInfoLookup *getExternalIdentifierLookup() const {
return ExternalLookup;
llvm::BumpPtrAllocator& getAllocator() {
return HashTable.getAllocator();
/// Return the identifier token info for the specified named
/// identifier.
IdentifierInfo &get(StringRef Name) {
auto &Entry = *HashTable.insert(std::make_pair(Name, nullptr)).first;
IdentifierInfo *&II = Entry.second;
if (II) return *II;
// No entry; if we have an external lookup, look there first.
if (ExternalLookup) {
II = ExternalLookup->get(Name);
if (II)
return *II;
// Lookups failed, make a new IdentifierInfo.
void *Mem = getAllocator().Allocate<IdentifierInfo>();
II = new (Mem) IdentifierInfo();
// Make sure getName() knows how to find the IdentifierInfo
// contents.
II->Entry = &Entry;
return *II;
IdentifierInfo &get(StringRef Name, tok::TokenKind TokenCode) {
IdentifierInfo &II = get(Name);
II.TokenID = TokenCode;
assert(II.TokenID == (unsigned) TokenCode && "TokenCode too large");
return II;
/// Gets an IdentifierInfo for the given name without consulting
/// external sources.
/// This is a version of get() meant for external sources that want to
/// introduce or modify an identifier. If they called get(), they would
/// likely end up in a recursion.
IdentifierInfo &getOwn(StringRef Name) {
auto &Entry = *HashTable.insert(std::make_pair(Name, nullptr)).first;
IdentifierInfo *&II = Entry.second;
if (II)
return *II;
// Lookups failed, make a new IdentifierInfo.
void *Mem = getAllocator().Allocate<IdentifierInfo>();
II = new (Mem) IdentifierInfo();
// Make sure getName() knows how to find the IdentifierInfo
// contents.
II->Entry = &Entry;
// If this is the 'import' contextual keyword, mark it as such.
if (Name.equals("import"))
return *II;
using iterator = HashTableTy::const_iterator;
using const_iterator = HashTableTy::const_iterator;
iterator begin() const { return HashTable.begin(); }
iterator end() const { return HashTable.end(); }
unsigned size() const { return HashTable.size(); }
/// Print some statistics to stderr that indicate how well the
/// hashing is doing.
void PrintStats() const;
/// Populate the identifier table with info about the language keywords
/// for the language specified by \p LangOpts.
void AddKeywords(const LangOptions &LangOpts);
/// A family of Objective-C methods.
/// These families have no inherent meaning in the language, but are
/// nonetheless central enough in the existing implementations to
/// merit direct AST support. While, in theory, arbitrary methods can
/// be considered to form families, we focus here on the methods
/// involving allocation and retain-count management, as these are the
/// most "core" and the most likely to be useful to diverse clients
/// without extra information.
/// Both selectors and actual method declarations may be classified
/// into families. Method families may impose additional restrictions
/// beyond their selector name; for example, a method called '_init'
/// that returns void is not considered to be in the 'init' family
/// (but would be if it returned 'id'). It is also possible to
/// explicitly change or remove a method's family. Therefore the
/// method's family should be considered the single source of truth.
enum ObjCMethodFamily {
/// No particular method family.
// Selectors in these families may have arbitrary arity, may be
// written with arbitrary leading underscores, and may have
// additional CamelCase "words" in their first selector chunk
// following the family name.
// These families are singletons consisting only of the nullary
// selector with the given name.
// performSelector families
/// Enough bits to store any enumerator in ObjCMethodFamily or
/// InvalidObjCMethodFamily.
enum { ObjCMethodFamilyBitWidth = 4 };
/// An invalid value of ObjCMethodFamily.
enum { InvalidObjCMethodFamily = (1 << ObjCMethodFamilyBitWidth) - 1 };
/// A family of Objective-C methods.
/// These are family of methods whose result type is initially 'id', but
/// but are candidate for the result type to be changed to 'instancetype'.
enum ObjCInstanceTypeFamily {
enum ObjCStringFormatFamily {
/// Smart pointer class that efficiently represents Objective-C method
/// names.
/// This class will either point to an IdentifierInfo or a
/// MultiKeywordSelector (which is private). This enables us to optimize
/// selectors that take no arguments and selectors that take 1 argument, which
/// accounts for 78% of all selectors in Cocoa.h.
class Selector {
friend class Diagnostic;
friend class SelectorTable; // only the SelectorTable can create these
friend class DeclarationName; // and the AST's DeclarationName.
enum IdentifierInfoFlag {
// Empty selector = 0. Note that these enumeration values must
// correspond to the enumeration values of DeclarationName::StoredNameKind
ZeroArg = 0x01,
OneArg = 0x02,
MultiArg = 0x07,
ArgFlags = 0x07
/// A pointer to the MultiKeywordSelector or IdentifierInfo. We use the low
/// three bits of InfoPtr to store an IdentifierInfoFlag. Note that in any
/// case IdentifierInfo and MultiKeywordSelector are already aligned to
/// 8 bytes even on 32 bits archs because of DeclarationName.
uintptr_t InfoPtr = 0;
Selector(IdentifierInfo *II, unsigned nArgs) {
InfoPtr = reinterpret_cast<uintptr_t>(II);
assert((InfoPtr & ArgFlags) == 0 &&"Insufficiently aligned IdentifierInfo");
assert(nArgs < 2 && "nArgs not equal to 0/1");
InfoPtr |= nArgs+1;
Selector(MultiKeywordSelector *SI) {
InfoPtr = reinterpret_cast<uintptr_t>(SI);
assert((InfoPtr & ArgFlags) == 0 &&"Insufficiently aligned IdentifierInfo");
InfoPtr |= MultiArg;
IdentifierInfo *getAsIdentifierInfo() const {
if (getIdentifierInfoFlag() < MultiArg)
return reinterpret_cast<IdentifierInfo *>(InfoPtr & ~ArgFlags);
return nullptr;
MultiKeywordSelector *getMultiKeywordSelector() const {
return reinterpret_cast<MultiKeywordSelector *>(InfoPtr & ~ArgFlags);
unsigned getIdentifierInfoFlag() const {
return InfoPtr & ArgFlags;
static ObjCMethodFamily getMethodFamilyImpl(Selector sel);
static ObjCStringFormatFamily getStringFormatFamilyImpl(Selector sel);
/// The default ctor should only be used when creating data structures that
/// will contain selectors.
Selector() = default;
explicit Selector(uintptr_t V) : InfoPtr(V) {}
/// operator==/!= - Indicate whether the specified selectors are identical.
bool operator==(Selector RHS) const {
return InfoPtr == RHS.InfoPtr;
bool operator!=(Selector RHS) const {
return InfoPtr != RHS.InfoPtr;
void *getAsOpaquePtr() const {
return reinterpret_cast<void*>(InfoPtr);
/// Determine whether this is the empty selector.
bool isNull() const { return InfoPtr == 0; }
// Predicates to identify the selector type.
bool isKeywordSelector() const {
return getIdentifierInfoFlag() != ZeroArg;
bool isUnarySelector() const {
return getIdentifierInfoFlag() == ZeroArg;
/// If this selector is the specific keyword selector described by Names.
bool isKeywordSelector(ArrayRef<StringRef> Names) const;
/// If this selector is the specific unary selector described by Name.
bool isUnarySelector(StringRef Name) const;
unsigned getNumArgs() const;
/// Retrieve the identifier at a given position in the selector.
/// Note that the identifier pointer returned may be NULL. Clients that only
/// care about the text of the identifier string, and not the specific,
/// uniqued identifier pointer, should use \c getNameForSlot(), which returns
/// an empty string when the identifier pointer would be NULL.
/// \param argIndex The index for which we want to retrieve the identifier.
/// This index shall be less than \c getNumArgs() unless this is a keyword
/// selector, in which case 0 is the only permissible value.
/// \returns the uniqued identifier for this slot, or NULL if this slot has
/// no corresponding identifier.
IdentifierInfo *getIdentifierInfoForSlot(unsigned argIndex) const;
/// Retrieve the name at a given position in the selector.
/// \param argIndex The index for which we want to retrieve the name.
/// This index shall be less than \c getNumArgs() unless this is a keyword
/// selector, in which case 0 is the only permissible value.
/// \returns the name for this slot, which may be the empty string if no
/// name was supplied.
StringRef getNameForSlot(unsigned argIndex) const;
/// Derive the full selector name (e.g. "foo:bar:") and return
/// it as an std::string.
std::string getAsString() const;
/// Prints the full selector name (e.g. "foo:bar:").
void print(llvm::raw_ostream &OS) const;
void dump() const;
/// Derive the conventional family of this method.
ObjCMethodFamily getMethodFamily() const {
return getMethodFamilyImpl(*this);
ObjCStringFormatFamily getStringFormatFamily() const {
return getStringFormatFamilyImpl(*this);
static Selector getEmptyMarker() {
return Selector(uintptr_t(-1));
static Selector getTombstoneMarker() {
return Selector(uintptr_t(-2));
static ObjCInstanceTypeFamily getInstTypeMethodFamily(Selector sel);
/// This table allows us to fully hide how we implement
/// multi-keyword caching.
class SelectorTable {
// Actually a SelectorTableImpl
void *Impl;
SelectorTable(const SelectorTable &) = delete;
SelectorTable &operator=(const SelectorTable &) = delete;
/// Can create any sort of selector.
/// \p NumArgs indicates whether this is a no argument selector "foo", a
/// single argument selector "foo:" or multi-argument "foo:bar:".
Selector getSelector(unsigned NumArgs, IdentifierInfo **IIV);
Selector getUnarySelector(IdentifierInfo *ID) {
return Selector(ID, 1);
Selector getNullarySelector(IdentifierInfo *ID) {
return Selector(ID, 0);
/// Return the total amount of memory allocated for managing selectors.
size_t getTotalMemory() const;
/// Return the default setter name for the given identifier.
/// This is "set" + \p Name where the initial character of \p Name
/// has been capitalized.
static SmallString<64> constructSetterName(StringRef Name);
/// Return the default setter selector for the given identifier.
/// This is "set" + \p Name where the initial character of \p Name
/// has been capitalized.
static Selector constructSetterSelector(IdentifierTable &Idents,
SelectorTable &SelTable,
const IdentifierInfo *Name);
/// Return the property name for the given setter selector.
static std::string getPropertyNameFromSetterSelector(Selector Sel);
namespace detail {
/// DeclarationNameExtra is used as a base of various uncommon special names.
/// This class is needed since DeclarationName has not enough space to store
/// the kind of every possible names. Therefore the kind of common names is
/// stored directly in DeclarationName, and the kind of uncommon names is
/// stored in DeclarationNameExtra. It is aligned to 8 bytes because
/// DeclarationName needs the lower 3 bits to store the kind of common names.
/// DeclarationNameExtra is tightly coupled to DeclarationName and any change
/// here is very likely to require changes in DeclarationName(Table).
class alignas(IdentifierInfoAlignment) DeclarationNameExtra {
friend class clang::DeclarationName;
friend class clang::DeclarationNameTable;
/// The kind of "extra" information stored in the DeclarationName. See
/// @c ExtraKindOrNumArgs for an explanation of how these enumerator values
/// are used. Note that DeclarationName depends on the numerical values
/// of the enumerators in this enum. See DeclarationName::StoredNameKind
/// for more info.
enum ExtraKind {
/// ExtraKindOrNumArgs has one of the following meaning:
/// * The kind of an uncommon C++ special name. This DeclarationNameExtra
/// is in this case in fact either a CXXDeductionGuideNameExtra or
/// a CXXLiteralOperatorIdName.
/// * It may be also name common to C++ using-directives (CXXUsingDirective),
/// * Otherwise it is ObjCMultiArgSelector+NumArgs, where NumArgs is
/// the number of arguments in the Objective-C selector, in which
/// case the DeclarationNameExtra is also a MultiKeywordSelector.
unsigned ExtraKindOrNumArgs;
DeclarationNameExtra(ExtraKind Kind) : ExtraKindOrNumArgs(Kind) {}
DeclarationNameExtra(unsigned NumArgs)
: ExtraKindOrNumArgs(ObjCMultiArgSelector + NumArgs) {}
/// Return the corresponding ExtraKind.
ExtraKind getKind() const {
return static_cast<ExtraKind>(ExtraKindOrNumArgs >
? (unsigned)ObjCMultiArgSelector
: ExtraKindOrNumArgs);
/// Return the number of arguments in an ObjC selector. Only valid when this
/// is indeed an ObjCMultiArgSelector.
unsigned getNumArgs() const {
assert(ExtraKindOrNumArgs >= (unsigned)ObjCMultiArgSelector &&
"getNumArgs called but this is not an ObjC selector!");
return ExtraKindOrNumArgs - (unsigned)ObjCMultiArgSelector;
} // namespace detail
} // namespace clang
namespace llvm {
/// Define DenseMapInfo so that Selectors can be used as keys in DenseMap and
/// DenseSets.
template <>
struct DenseMapInfo<clang::Selector> {
static clang::Selector getEmptyKey() {
return clang::Selector::getEmptyMarker();
static clang::Selector getTombstoneKey() {
return clang::Selector::getTombstoneMarker();
static unsigned getHashValue(clang::Selector S);
static bool isEqual(clang::Selector LHS, clang::Selector RHS) {
return LHS == RHS;
struct PointerLikeTypeTraits<clang::Selector> {
static const void *getAsVoidPointer(clang::Selector P) {
return P.getAsOpaquePtr();
static clang::Selector getFromVoidPointer(const void *P) {
return clang::Selector(reinterpret_cast<uintptr_t>(P));
enum { NumLowBitsAvailable = 0 };
// Provide PointerLikeTypeTraits for IdentifierInfo pointers, which
// are not guaranteed to be 8-byte aligned.
struct PointerLikeTypeTraits<clang::IdentifierInfo*> {
static void *getAsVoidPointer(clang::IdentifierInfo* P) {
return P;
static clang::IdentifierInfo *getFromVoidPointer(void *P) {
return static_cast<clang::IdentifierInfo*>(P);
enum { NumLowBitsAvailable = 1 };
struct PointerLikeTypeTraits<const clang::IdentifierInfo*> {
static const void *getAsVoidPointer(const clang::IdentifierInfo* P) {
return P;
static const clang::IdentifierInfo *getFromVoidPointer(const void *P) {
return static_cast<const clang::IdentifierInfo*>(P);
enum { NumLowBitsAvailable = 1 };
} // namespace llvm