lib/ClangImporter/ImportName.h - third_party/swift - Git at Google

 //===--- ImportName.h - Imported Swift names for Clang decls ----*- C++ -*-===//
 //
 // This source file is part of the Swift.org open source project
 //
 // Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
 // Licensed under Apache License v2.0 with Runtime Library Exception
 //
 // See https://swift.org/LICENSE.txt for license information
 // See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
 //
 //===----------------------------------------------------------------------===//
 //
 // This file provides class definitions for naming-related concerns in the
 // ClangImporter.
 //
 //===----------------------------------------------------------------------===//
 #ifndef SWIFT_IMPORT_NAME_H
 #define SWIFT_IMPORT_NAME_H

 #include "ImportEnumInfo.h"
 #include "SwiftLookupTable.h"
 #include "swift/Basic/StringExtras.h"
 #include "swift/Basic/Version.h"
 #include "swift/AST/ASTContext.h"
 #include "swift/AST/Decl.h"
 #include "swift/AST/ForeignErrorConvention.h"
 #include "clang/Sema/Sema.h"

 namespace swift {
 namespace importer {
 struct PlatformAvailability;

 /// The kind of accessor that an entity will be imported as.
 enum class ImportedAccessorKind : unsigned {
   None = 0,
   PropertyGetter,
   PropertySetter,
   SubscriptGetter,
   SubscriptSetter,
 };
 enum { NumImportedAccessorKindBits = 3 };

 /// The name version
 class ImportNameVersion : public RelationalOperationsBase<ImportNameVersion> {
   unsigned rawValue;
   friend llvm::DenseMapInfo<ImportNameVersion>;

   enum AsConstExpr_t { AsConstExpr };

   constexpr ImportNameVersion() : rawValue(0) {}
   constexpr ImportNameVersion(unsigned version, AsConstExpr_t)
       : rawValue(version) {}
   explicit ImportNameVersion(unsigned version) : rawValue(version) {
     assert(version >= 2 && "only Swift 2 and later are supported");
   }
 public:
   /// Map a language version into an import name version.
   static ImportNameVersion fromOptions(const LangOptions &langOpts) {
     // We encode the 'rawValue' as just major version numbers with the
     // exception of '4.2', which is a special minor version that can impact
     // importing of names.  We treat that with a rawValue of 5, and treat
     // all major values of 5 or higher as being rawValue = majorversion + 1.
     const auto &version = langOpts.EffectiveLanguageVersion;
     // If the effective version is 4.x, where x >= 2, the import version
     // is 4.2.
     if (version.size() > 1 && version[0] == 4 && version[1] >= 2) {
       return ImportNameVersion::swift4_2();
     }
     unsigned major = version[0];
     return ImportNameVersion(major >= 5 ? major + 1 : major);
   }

   unsigned majorVersionNumber() const {
     assert(*this != ImportNameVersion::raw());
     if (*this == ImportNameVersion::swift4_2())
       return 4;
     return rawValue < 5 ? rawValue : rawValue - 1;
   }

   unsigned minorVersionNumber() const {
     assert(*this != ImportNameVersion::raw());
     if (*this == ImportNameVersion::swift4_2())
       return 2;
     return 0;
   }

   llvm::VersionTuple asClangVersionTuple() const {
     assert(*this != ImportNameVersion::raw());
     return llvm::VersionTuple(majorVersionNumber(), minorVersionNumber());
   }

   bool operator==(ImportNameVersion other) const {
     return rawValue == other.rawValue;
   }
   bool operator<(ImportNameVersion other) const {
     return rawValue < other.rawValue;
   }

   /// Calls \p action for each name version other than this one, first going
   /// backwards until ImportNameVersion::raw(), and then going forwards to
   /// ImportNameVersion::maxVersion().
   ///
   /// This is the most useful order for importing compatibility stubs.
   void forEachOtherImportNameVersion(
       llvm::function_ref<void(ImportNameVersion)> action) const {
     assert(*this >= ImportNameVersion::swift2());

     ImportNameVersion nameVersion = *this;
     while (nameVersion > ImportNameVersion::swift2()) {
       --nameVersion.rawValue;
       action(nameVersion);
     }

     action(ImportNameVersion::raw());

     nameVersion = *this;
     while (nameVersion < ImportNameVersion::maxVersion()) {
       ++nameVersion.rawValue;
       action(nameVersion);
     }
   }

   /// Names as they appear in C/ObjC.
   static constexpr inline ImportNameVersion raw() {
     return ImportNameVersion{};
   }

   /// Names as they appeared in Swift 2 family.
   static constexpr inline ImportNameVersion swift2() {
     return ImportNameVersion{2, AsConstExpr};
   }

   /// Names as they appeared in Swift 4.2 family.
   static constexpr inline ImportNameVersion swift4_2() {
     return ImportNameVersion{5, AsConstExpr};
   }

   /// The latest supported version.
   ///
   /// FIXME: All other version information is in Version.h. Can this go there
   /// instead?
   static constexpr inline ImportNameVersion maxVersion() {
     return ImportNameVersion{6, AsConstExpr};
   }

   /// The version which should be used for importing types, which need to have
   /// one canonical definition.
   ///
   /// FIXME: Is this supposed to be the /newest/ version, or a canonical
   /// version that lasts forever as part of the ABI?
   static constexpr inline ImportNameVersion forTypes() {
     return ImportNameVersion::maxVersion();
   }
 };

 /// Describes a name that was imported from Clang.
 class ImportedName {
   friend class NameImporter;

   /// The imported name.
   DeclName declName;

   /// The context into which this declaration will be imported.
   ///
   /// When the context into which the declaration will be imported
   /// matches a Clang declaration context (the common case), the
   /// result will be expressed as a declaration context. Otherwise,
   /// if the Clang type is not itself a declaration context (for
   /// example, a typedef that comes into Swift as a strong type),
   /// the type declaration will be provided.
   EffectiveClangContext effectiveContext;

   struct Info {
     /// For names that map Objective-C error handling conventions into
     /// throwing Swift methods, describes how the mapping is performed.
     ForeignErrorConvention::Info errorInfo;

     /// For a declaration name that makes the declaration into an
     /// instance member, the index of the "Self" parameter.
     unsigned selfIndex;

     /// For an initializer, the kind of initializer to import.
     CtorInitializerKind initKind;

     /// What kind of accessor this name refers to, if any.
     ImportedAccessorKind accessorKind : NumImportedAccessorKindBits;

     /// Whether this name was explicitly specified via a Clang
     /// swift_name attribute.
     unsigned hasCustomName : 1;

     /// Whether this was one of a special class of Objective-C
     /// initializers for which we drop the variadic argument rather
     /// than refuse to import the initializer.
     unsigned droppedVariadic : 1;

     /// Whether this is a global being imported as a member
     unsigned importAsMember : 1;

     unsigned hasSelfIndex : 1;

     unsigned hasErrorInfo : 1;

     Info()
         : errorInfo(), selfIndex(), initKind(CtorInitializerKind::Designated),
           accessorKind(ImportedAccessorKind::None), hasCustomName(false),
           droppedVariadic(false), importAsMember(false), hasSelfIndex(false),
           hasErrorInfo(false) {}
   } info;

 public:
   ImportedName() = default;

   /// Produce just the imported name, for clients that don't care
   /// about the details.
   DeclName getDeclName() const { return declName; }
   operator DeclName() const { return getDeclName(); }
   void setDeclName(DeclName name) { declName = name; }

   /// The context into which this declaration will be imported.
   EffectiveClangContext getEffectiveContext() const {
     return effectiveContext;
   }
   void setEffectiveContext(EffectiveClangContext ctx) {
     effectiveContext = ctx;
   }

   /// For an initializer, the kind of initializer to import.
   CtorInitializerKind getInitKind() const { return info.initKind; }

   /// What kind of accessor this name refers to, if any.
   ImportedAccessorKind getAccessorKind() const { return info.accessorKind; }

   /// For names that map Objective-C error handling conventions into
   /// throwing Swift methods, describes how the mapping is performed.
   Optional<ForeignErrorConvention::Info> getErrorInfo() const {
     if (info.hasErrorInfo)
       return info.errorInfo;
     return None;
   }

   /// For a declaration name that makes the declaration into an
   /// instance member, the index of the "Self" parameter.
   Optional<unsigned> getSelfIndex() const {
     if (info.hasSelfIndex)
       return info.selfIndex;
     return None;
   }

   /// Whether this name was explicitly specified via a Clang
   /// swift_name attribute.
   bool hasCustomName() const { return info.hasCustomName; }
   void setHasCustomName() { info.hasCustomName = true; }

   /// Whether this was one of a special class of Objective-C
   /// initializers for which we drop the variadic argument rather
   /// than refuse to import the initializer.
   bool droppedVariadic() const { return info.droppedVariadic; }

   /// Whether this is a global being imported as a member
   bool importAsMember() const { return info.importAsMember; }

   /// Whether any name was imported.
   explicit operator bool() const { return static_cast<bool>(declName); }

   /// Whether this declaration is a property accessor (getter or setter).
   bool isPropertyAccessor() const {
     switch (getAccessorKind()) {
     case ImportedAccessorKind::None:
     case ImportedAccessorKind::SubscriptGetter:
     case ImportedAccessorKind::SubscriptSetter:
       return false;

     case ImportedAccessorKind::PropertyGetter:
     case ImportedAccessorKind::PropertySetter:
       return true;
     }
   }

   /// Whether this declaration is a subscript accessor (getter or setter).
   bool isSubscriptAccessor() const {
     switch (getAccessorKind()) {
     case ImportedAccessorKind::None:
     case ImportedAccessorKind::PropertyGetter:
     case ImportedAccessorKind::PropertySetter:
       return false;

     case ImportedAccessorKind::SubscriptGetter:
     case ImportedAccessorKind::SubscriptSetter:
       return true;
     }

     llvm_unreachable("Invalid ImportedAccessorKind.");
   }
 };

 /// Strips a trailing "Notification", if present. Returns {} if name doesn't end
 /// in "Notification", or it there would be nothing left.
 StringRef stripNotification(StringRef name);

 /// Class to determine the Swift name of foreign entities. Currently fairly
 /// stateless and borrows from the ClangImporter::Implementation, but in the
 /// future will be more self-contained and encapsulated.
 class NameImporter {
   ASTContext &swiftCtx;
   const PlatformAvailability &availability;

   clang::Sema &clangSema;
   EnumInfoCache enumInfos;
   StringScratchSpace scratch;

   const bool inferImportAsMember;

   // TODO: remove when we drop the options (i.e. import all names)
   using CacheKeyType =
       std::pair<const clang::NamedDecl *, ImportNameVersion>;

   /// Cache for repeated calls
   llvm::DenseMap<CacheKeyType, ImportedName> importNameCache;

   /// The set of property names that show up in the defining module of
   /// an Objective-C class.
   llvm::DenseMap<std::pair<const clang::ObjCInterfaceDecl *, char>,
                  std::unique_ptr<InheritedNameSet>> allProperties;

 public:
   NameImporter(ASTContext &ctx, const PlatformAvailability &avail,
                clang::Sema &cSema, bool inferIAM)
       : swiftCtx(ctx), availability(avail), clangSema(cSema),
         enumInfos(clangSema.getPreprocessor()),
         inferImportAsMember(inferIAM) {}

   /// Determine the Swift name for a Clang decl
   ImportedName importName(const clang::NamedDecl *decl,
                           ImportNameVersion version,
                           clang::DeclarationName preferredName =
                             clang::DeclarationName());

   /// Attempts to import the name of \p decl with each possible
   /// ImportNameVersion. \p action will be called with each unique name.
   ///
   /// In this case, "unique" means either the full name is distinct or the
   /// effective context is distinct. This method does not attempt to handle
   /// "unresolved" contexts in any special way---if one name references a
   /// particular Clang declaration and the other has an unresolved context that
   /// will eventually reference that declaration, the contexts will still be
   /// considered distinct.
   ///
   /// If \p action returns false, the current name will \e not be added to the
   /// set of seen names.
   ///
   /// The active name for \p activeVerion is always first, followed by the
   /// other names in the order of
   /// ImportNameVersion::forEachOtherImportNameVersion.
   ///
   /// Returns \c true if it fails to import name for the active version.
   bool forEachDistinctImportName(
       const clang::NamedDecl *decl, ImportNameVersion activeVersion,
       llvm::function_ref<bool(ImportedName, ImportNameVersion)> action);

   /// Imports the name of the given Clang macro into Swift.
   Identifier importMacroName(const clang::IdentifierInfo *clangIdentifier,
                              const clang::MacroInfo *macro);

   ASTContext &getContext() { return swiftCtx; }
   const LangOptions &getLangOpts() const { return swiftCtx.LangOpts; }

   Identifier getIdentifier(StringRef name) {
     return swiftCtx.getIdentifier(name);
   }

   StringScratchSpace &getScratch() { return scratch; }

   bool isInferImportAsMember() const { return inferImportAsMember; }

   EnumInfo getEnumInfo(const clang::EnumDecl *decl) {
     return enumInfos.getEnumInfo(decl);
   }
   EnumKind getEnumKind(const clang::EnumDecl *decl) {
     return enumInfos.getEnumKind(decl);
   }

   clang::Sema &getClangSema() { return clangSema; }
   clang::ASTContext &getClangContext() {
     return getClangSema().getASTContext();
   }
   clang::Preprocessor &getClangPreprocessor() {
     return getClangSema().getPreprocessor();
   }

   /// Retrieve the inherited name set for the given Objective-C class.
   const InheritedNameSet *getAllPropertyNames(
                             clang::ObjCInterfaceDecl *classDecl,
                             bool forInstance);

 private:
   bool enableObjCInterop() const { return swiftCtx.LangOpts.EnableObjCInterop; }

   /// Look for a method that will import to have the same name as the
   /// given method after importing the Nth parameter as an elided error
   /// parameter.
   bool hasErrorMethodNameCollision(const clang::ObjCMethodDecl *method,
                                    unsigned paramIndex,
                                    StringRef suffixToStrip);

   /// Test to see if there is a value with the same name as 'proposedName' in
   /// the same module as the decl
   bool hasNamingConflict(const clang::NamedDecl *decl,
                          const clang::IdentifierInfo *proposedName,
                          const clang::TypedefNameDecl *cfTypedef);

   Optional<ForeignErrorConvention::Info>
   considerErrorImport(const clang::ObjCMethodDecl *clangDecl,
                       StringRef &baseName,
                       SmallVectorImpl<StringRef> &paramNames,
                       ArrayRef<const clang::ParmVarDecl *> params,
                       bool isInitializer, bool hasCustomName);

   EffectiveClangContext determineEffectiveContext(const clang::NamedDecl *,
                                                   const clang::DeclContext *,
                                                   ImportNameVersion version);

   ImportedName importNameImpl(const clang::NamedDecl *,
                               ImportNameVersion version,
                               clang::DeclarationName);
 };

 }
 }

 namespace llvm {
 // Provide DenseMapInfo for ImportNameVersion.
 template <> struct DenseMapInfo<swift::importer::ImportNameVersion> {
   using ImportNameVersion = swift::importer::ImportNameVersion;
   using DMIU = DenseMapInfo<unsigned>;
   static inline ImportNameVersion getEmptyKey() {
     return (ImportNameVersion)DMIU::getEmptyKey();
   }
   static inline ImportNameVersion getTombstoneKey() {
     return (ImportNameVersion)DMIU::getTombstoneKey();
   }
   static unsigned getHashValue(const ImportNameVersion &Val) {
     return DMIU::getHashValue(Val.rawValue);
   }
   static bool isEqual(const ImportNameVersion &LHS,
                       const ImportNameVersion &RHS) {
     return LHS == RHS;
   }
 };
 }

 #endif
	//===--- ImportName.h - Imported Swift names for Clang decls ----- C++ --===//
	//
	// This source file is part of the Swift.org open source project
	//
	// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
	// Licensed under Apache License v2.0 with Runtime Library Exception
	//
	// See https://swift.org/LICENSE.txt for license information
	// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
	//
	//===----------------------------------------------------------------------===//
	//
	// This file provides class definitions for naming-related concerns in the
	// ClangImporter.
	//
	//===----------------------------------------------------------------------===//
	#ifndef SWIFT_IMPORT_NAME_H
	#define SWIFT_IMPORT_NAME_H

	#include "ImportEnumInfo.h"
	#include "SwiftLookupTable.h"
	#include "swift/Basic/StringExtras.h"
	#include "swift/Basic/Version.h"
	#include "swift/AST/ASTContext.h"
	#include "swift/AST/Decl.h"
	#include "swift/AST/ForeignErrorConvention.h"
	#include "clang/Sema/Sema.h"

	namespace swift {
	namespace importer {
	struct PlatformAvailability;

	/// The kind of accessor that an entity will be imported as.
	enum class ImportedAccessorKind : unsigned {
	None = 0,
	PropertyGetter,
	PropertySetter,
	SubscriptGetter,
	SubscriptSetter,
	};
	enum { NumImportedAccessorKindBits = 3 };

	/// The name version
	class ImportNameVersion : public RelationalOperationsBase<ImportNameVersion> {
	unsigned rawValue;
	friend llvm::DenseMapInfo<ImportNameVersion>;

	enum AsConstExpr_t { AsConstExpr };

	constexpr ImportNameVersion() : rawValue(0) {}
	constexpr ImportNameVersion(unsigned version, AsConstExpr_t)
	: rawValue(version) {}
	explicit ImportNameVersion(unsigned version) : rawValue(version) {
	assert(version >= 2 && "only Swift 2 and later are supported");
	}
	public:
	/// Map a language version into an import name version.
	static ImportNameVersion fromOptions(const LangOptions &langOpts) {
	// We encode the 'rawValue' as just major version numbers with the
	// exception of '4.2', which is a special minor version that can impact
	// importing of names. We treat that with a rawValue of 5, and treat
	// all major values of 5 or higher as being rawValue = majorversion + 1.
	const auto &version = langOpts.EffectiveLanguageVersion;
	// If the effective version is 4.x, where x >= 2, the import version
	// is 4.2.
	if (version.size() > 1 && version[0] == 4 && version[1] >= 2) {
	return ImportNameVersion::swift4_2();
	}
	unsigned major = version[0];
	return ImportNameVersion(major >= 5 ? major + 1 : major);
	}

	unsigned majorVersionNumber() const {
	assert(*this != ImportNameVersion::raw());
	if (*this == ImportNameVersion::swift4_2())
	return 4;
	return rawValue < 5 ? rawValue : rawValue - 1;
	}

	unsigned minorVersionNumber() const {
	assert(*this != ImportNameVersion::raw());
	if (*this == ImportNameVersion::swift4_2())
	return 2;
	return 0;
	}

	llvm::VersionTuple asClangVersionTuple() const {
	assert(*this != ImportNameVersion::raw());
	return llvm::VersionTuple(majorVersionNumber(), minorVersionNumber());
	}

	bool operator==(ImportNameVersion other) const {
	return rawValue == other.rawValue;
	}
	bool operator<(ImportNameVersion other) const {
	return rawValue < other.rawValue;
	}

	/// Calls \p action for each name version other than this one, first going
	/// backwards until ImportNameVersion::raw(), and then going forwards to
	/// ImportNameVersion::maxVersion().
	///
	/// This is the most useful order for importing compatibility stubs.
	void forEachOtherImportNameVersion(
	llvm::function_ref<void(ImportNameVersion)> action) const {
	assert(*this >= ImportNameVersion::swift2());

	ImportNameVersion nameVersion = *this;
	while (nameVersion > ImportNameVersion::swift2()) {
	--nameVersion.rawValue;
	action(nameVersion);
	}

	action(ImportNameVersion::raw());

	nameVersion = *this;
	while (nameVersion < ImportNameVersion::maxVersion()) {
	++nameVersion.rawValue;
	action(nameVersion);
	}
	}

	/// Names as they appear in C/ObjC.
	static constexpr inline ImportNameVersion raw() {
	return ImportNameVersion{};
	}

	/// Names as they appeared in Swift 2 family.
	static constexpr inline ImportNameVersion swift2() {
	return ImportNameVersion{2, AsConstExpr};
	}

	/// Names as they appeared in Swift 4.2 family.
	static constexpr inline ImportNameVersion swift4_2() {
	return ImportNameVersion{5, AsConstExpr};
	}

	/// The latest supported version.
	///
	/// FIXME: All other version information is in Version.h. Can this go there
	/// instead?
	static constexpr inline ImportNameVersion maxVersion() {
	return ImportNameVersion{6, AsConstExpr};
	}

	/// The version which should be used for importing types, which need to have
	/// one canonical definition.
	///
	/// FIXME: Is this supposed to be the /newest/ version, or a canonical
	/// version that lasts forever as part of the ABI?
	static constexpr inline ImportNameVersion forTypes() {
	return ImportNameVersion::maxVersion();
	}
	};

	/// Describes a name that was imported from Clang.
	class ImportedName {
	friend class NameImporter;

	/// The imported name.
	DeclName declName;

	/// The context into which this declaration will be imported.
	///
	/// When the context into which the declaration will be imported
	/// matches a Clang declaration context (the common case), the
	/// result will be expressed as a declaration context. Otherwise,
	/// if the Clang type is not itself a declaration context (for
	/// example, a typedef that comes into Swift as a strong type),
	/// the type declaration will be provided.
	EffectiveClangContext effectiveContext;

	struct Info {
	/// For names that map Objective-C error handling conventions into
	/// throwing Swift methods, describes how the mapping is performed.
	ForeignErrorConvention::Info errorInfo;

	/// For a declaration name that makes the declaration into an
	/// instance member, the index of the "Self" parameter.
	unsigned selfIndex;

	/// For an initializer, the kind of initializer to import.
	CtorInitializerKind initKind;

	/// What kind of accessor this name refers to, if any.
	ImportedAccessorKind accessorKind : NumImportedAccessorKindBits;

	/// Whether this name was explicitly specified via a Clang
	/// swift_name attribute.
	unsigned hasCustomName : 1;

	/// Whether this was one of a special class of Objective-C
	/// initializers for which we drop the variadic argument rather
	/// than refuse to import the initializer.
	unsigned droppedVariadic : 1;

	/// Whether this is a global being imported as a member
	unsigned importAsMember : 1;

	unsigned hasSelfIndex : 1;

	unsigned hasErrorInfo : 1;

	Info()
	: errorInfo(), selfIndex(), initKind(CtorInitializerKind::Designated),
	accessorKind(ImportedAccessorKind::None), hasCustomName(false),
	droppedVariadic(false), importAsMember(false), hasSelfIndex(false),
	hasErrorInfo(false) {}
	} info;

	public:
	ImportedName() = default;

	/// Produce just the imported name, for clients that don't care
	/// about the details.
	DeclName getDeclName() const { return declName; }
	operator DeclName() const { return getDeclName(); }
	void setDeclName(DeclName name) { declName = name; }

	/// The context into which this declaration will be imported.
	EffectiveClangContext getEffectiveContext() const {
	return effectiveContext;
	}
	void setEffectiveContext(EffectiveClangContext ctx) {
	effectiveContext = ctx;
	}

	/// For an initializer, the kind of initializer to import.
	CtorInitializerKind getInitKind() const { return info.initKind; }

	/// What kind of accessor this name refers to, if any.
	ImportedAccessorKind getAccessorKind() const { return info.accessorKind; }

	/// For names that map Objective-C error handling conventions into
	/// throwing Swift methods, describes how the mapping is performed.
	Optional<ForeignErrorConvention::Info> getErrorInfo() const {
	if (info.hasErrorInfo)
	return info.errorInfo;
	return None;
	}

	/// For a declaration name that makes the declaration into an
	/// instance member, the index of the "Self" parameter.
	Optional<unsigned> getSelfIndex() const {
	if (info.hasSelfIndex)
	return info.selfIndex;
	return None;
	}

	/// Whether this name was explicitly specified via a Clang
	/// swift_name attribute.
	bool hasCustomName() const { return info.hasCustomName; }
	void setHasCustomName() { info.hasCustomName = true; }

	/// Whether this was one of a special class of Objective-C
	/// initializers for which we drop the variadic argument rather
	/// than refuse to import the initializer.
	bool droppedVariadic() const { return info.droppedVariadic; }

	/// Whether this is a global being imported as a member
	bool importAsMember() const { return info.importAsMember; }

	/// Whether any name was imported.
	explicit operator bool() const { return static_cast<bool>(declName); }

	/// Whether this declaration is a property accessor (getter or setter).
	bool isPropertyAccessor() const {
	switch (getAccessorKind()) {
	case ImportedAccessorKind::None:
	case ImportedAccessorKind::SubscriptGetter:
	case ImportedAccessorKind::SubscriptSetter:
	return false;

	case ImportedAccessorKind::PropertyGetter:
	case ImportedAccessorKind::PropertySetter:
	return true;
	}
	}

	/// Whether this declaration is a subscript accessor (getter or setter).
	bool isSubscriptAccessor() const {
	switch (getAccessorKind()) {
	case ImportedAccessorKind::None:
	case ImportedAccessorKind::PropertyGetter:
	case ImportedAccessorKind::PropertySetter:
	return false;

	case ImportedAccessorKind::SubscriptGetter:
	case ImportedAccessorKind::SubscriptSetter:
	return true;
	}

	llvm_unreachable("Invalid ImportedAccessorKind.");
	}
	};

	/// Strips a trailing "Notification", if present. Returns {} if name doesn't end
	/// in "Notification", or it there would be nothing left.
	StringRef stripNotification(StringRef name);

	/// Class to determine the Swift name of foreign entities. Currently fairly
	/// stateless and borrows from the ClangImporter::Implementation, but in the
	/// future will be more self-contained and encapsulated.
	class NameImporter {
	ASTContext &swiftCtx;
	const PlatformAvailability &availability;

	clang::Sema &clangSema;
	EnumInfoCache enumInfos;
	StringScratchSpace scratch;

	const bool inferImportAsMember;

	// TODO: remove when we drop the options (i.e. import all names)
	using CacheKeyType =
	std::pair<const clang::NamedDecl *, ImportNameVersion>;

	/// Cache for repeated calls
	llvm::DenseMap<CacheKeyType, ImportedName> importNameCache;

	/// The set of property names that show up in the defining module of
	/// an Objective-C class.
	llvm::DenseMap<std::pair<const clang::ObjCInterfaceDecl *, char>,
	std::unique_ptr<InheritedNameSet>> allProperties;

	public:
	NameImporter(ASTContext &ctx, const PlatformAvailability &avail,
	clang::Sema &cSema, bool inferIAM)
	: swiftCtx(ctx), availability(avail), clangSema(cSema),
	enumInfos(clangSema.getPreprocessor()),
	inferImportAsMember(inferIAM) {}

	/// Determine the Swift name for a Clang decl
	ImportedName importName(const clang::NamedDecl *decl,
	ImportNameVersion version,
	clang::DeclarationName preferredName =
	clang::DeclarationName());

	/// Attempts to import the name of \p decl with each possible
	/// ImportNameVersion. \p action will be called with each unique name.
	///
	/// In this case, "unique" means either the full name is distinct or the
	/// effective context is distinct. This method does not attempt to handle
	/// "unresolved" contexts in any special way---if one name references a
	/// particular Clang declaration and the other has an unresolved context that
	/// will eventually reference that declaration, the contexts will still be
	/// considered distinct.
	///
	/// If \p action returns false, the current name will \e not be added to the
	/// set of seen names.
	///
	/// The active name for \p activeVerion is always first, followed by the
	/// other names in the order of
	/// ImportNameVersion::forEachOtherImportNameVersion.
	///
	/// Returns \c true if it fails to import name for the active version.
	bool forEachDistinctImportName(
	const clang::NamedDecl *decl, ImportNameVersion activeVersion,
	llvm::function_ref<bool(ImportedName, ImportNameVersion)> action);

	/// Imports the name of the given Clang macro into Swift.
	Identifier importMacroName(const clang::IdentifierInfo *clangIdentifier,
	const clang::MacroInfo *macro);

	ASTContext &getContext() { return swiftCtx; }
	const LangOptions &getLangOpts() const { return swiftCtx.LangOpts; }

	Identifier getIdentifier(StringRef name) {
	return swiftCtx.getIdentifier(name);
	}

	StringScratchSpace &getScratch() { return scratch; }

	bool isInferImportAsMember() const { return inferImportAsMember; }

	EnumInfo getEnumInfo(const clang::EnumDecl *decl) {
	return enumInfos.getEnumInfo(decl);
	}
	EnumKind getEnumKind(const clang::EnumDecl *decl) {
	return enumInfos.getEnumKind(decl);
	}

	clang::Sema &getClangSema() { return clangSema; }
	clang::ASTContext &getClangContext() {
	return getClangSema().getASTContext();
	}
	clang::Preprocessor &getClangPreprocessor() {
	return getClangSema().getPreprocessor();
	}

	/// Retrieve the inherited name set for the given Objective-C class.
	const InheritedNameSet *getAllPropertyNames(
	clang::ObjCInterfaceDecl *classDecl,
	bool forInstance);

	private:
	bool enableObjCInterop() const { return swiftCtx.LangOpts.EnableObjCInterop; }

	/// Look for a method that will import to have the same name as the
	/// given method after importing the Nth parameter as an elided error
	/// parameter.
	bool hasErrorMethodNameCollision(const clang::ObjCMethodDecl *method,
	unsigned paramIndex,
	StringRef suffixToStrip);

	/// Test to see if there is a value with the same name as 'proposedName' in
	/// the same module as the decl
	bool hasNamingConflict(const clang::NamedDecl *decl,
	const clang::IdentifierInfo *proposedName,
	const clang::TypedefNameDecl *cfTypedef);

	Optional<ForeignErrorConvention::Info>
	considerErrorImport(const clang::ObjCMethodDecl *clangDecl,
	StringRef &baseName,
	SmallVectorImpl<StringRef> &paramNames,
	ArrayRef<const clang::ParmVarDecl *> params,
	bool isInitializer, bool hasCustomName);

	EffectiveClangContext determineEffectiveContext(const clang::NamedDecl *,
	const clang::DeclContext *,
	ImportNameVersion version);

	ImportedName importNameImpl(const clang::NamedDecl *,
	ImportNameVersion version,
	clang::DeclarationName);
	};

	}
	}

	namespace llvm {
	// Provide DenseMapInfo for ImportNameVersion.
	template <> struct DenseMapInfo<swift::importer::ImportNameVersion> {
	using ImportNameVersion = swift::importer::ImportNameVersion;
	using DMIU = DenseMapInfo<unsigned>;
	static inline ImportNameVersion getEmptyKey() {
	return (ImportNameVersion)DMIU::getEmptyKey();
	}
	static inline ImportNameVersion getTombstoneKey() {
	return (ImportNameVersion)DMIU::getTombstoneKey();
	}
	static unsigned getHashValue(const ImportNameVersion &Val) {
	return DMIU::getHashValue(Val.rawValue);
	}
	static bool isEqual(const ImportNameVersion &LHS,
	const ImportNameVersion &RHS) {
	return LHS == RHS;
	}
	};
	}

	#endif