| //===--- EnumMetadataVisitor.h - CRTP for enum metadata ---------*- 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 |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // A CRTP class useful for visiting all of the fields in an |
| // enum metadata object. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef SWIFT_IRGEN_ENUMMETADATAVISITOR_H |
| #define SWIFT_IRGEN_ENUMMETADATAVISITOR_H |
| |
| #include "NominalMetadataVisitor.h" |
| #include "GenEnum.h" |
| |
| namespace swift { |
| namespace irgen { |
| |
| /// A CRTP class for laying out enum metadata. |
| /// |
| /// This produces an object corresponding to the EnumMetadata type. |
| /// It does not itself doing anything special for metadata templates. |
| template <class Impl> class EnumMetadataVisitor |
| : public NominalMetadataVisitor<Impl> { |
| using super = NominalMetadataVisitor<Impl>; |
| |
| protected: |
| using super::IGM; |
| using super::asImpl; |
| |
| /// The Enum. |
| EnumDecl *const Target; |
| |
| EnumMetadataVisitor(IRGenModule &IGM, EnumDecl *target) |
| : super(IGM), Target(target) {} |
| |
| public: |
| void layout() { |
| // Metadata header. |
| super::layout(); |
| |
| // EnumMetadata header. |
| asImpl().addNominalTypeDescriptor(); |
| |
| // Everything after this is type-specific. |
| asImpl().noteStartOfTypeSpecificMembers(); |
| |
| // Generic arguments. |
| // This must always be the first piece of trailing data. |
| asImpl().addGenericFields(Target); |
| |
| // Reserve a word to cache the payload size if the type has dynamic layout. |
| auto &strategy = getEnumImplStrategy(IGM, |
| Target->getDeclaredTypeInContext()->getCanonicalType()); |
| if (strategy.needsPayloadSizeInMetadata()) |
| asImpl().addPayloadSize(); |
| } |
| }; |
| |
| /// An "implementation" of EnumMetadataVisitor that just scans through |
| /// the metadata layout, maintaining the next index: the offset (in |
| /// pointer-sized chunks) into the metadata for the next field. |
| template <class Impl> |
| class EnumMetadataScanner : public EnumMetadataVisitor<Impl> { |
| using super = EnumMetadataVisitor<Impl>; |
| |
| protected: |
| Size NextOffset = Size(0); |
| |
| EnumMetadataScanner(IRGenModule &IGM, EnumDecl *target) |
| : super(IGM, target) {} |
| |
| public: |
| void addMetadataFlags() { addPointer(); } |
| void addValueWitnessTable() { addPointer(); } |
| void addNominalTypeDescriptor() { addPointer(); } |
| void addGenericArgument() { addPointer(); } |
| void addGenericWitnessTable() { addPointer(); } |
| void addPayloadSize() { addPointer(); } |
| void noteStartOfTypeSpecificMembers() {} |
| |
| private: |
| void addPointer() { |
| NextOffset += super::IGM.getPointerSize(); |
| } |
| }; |
| |
| } // end namespace irgen |
| } // end namespace swift |
| |
| #endif |