| //===--- MetadataLayout.h - CRTP for metadata layout ------------*- 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 helper class for laying out type metadata. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef SWIFT_IRGEN_METADATALAYOUT_H |
| #define SWIFT_IRGEN_METADATALAYOUT_H |
| |
| #include "llvm/ADT/SmallVector.h" |
| #include "swift/AST/Decl.h" |
| #include "swift/SIL/TypeLowering.h" |
| #include "GenericRequirement.h" |
| #include "GenProto.h" |
| #include "IRGenModule.h" |
| |
| namespace swift { |
| namespace irgen { |
| |
| /// A CRTP class for laying out type metadata. Note that this does |
| /// *not* handle the metadata template stuff. |
| template <class Impl> class MetadataLayout { |
| protected: |
| Impl &asImpl() { return *static_cast<Impl*>(this); } |
| |
| protected: |
| IRGenModule &IGM; |
| |
| MetadataLayout(IRGenModule &IGM) : IGM(IGM) {} |
| |
| public: |
| void layout() { |
| // Common fields. |
| asImpl().addValueWitnessTable(); |
| asImpl().noteAddressPoint(); |
| asImpl().addMetadataFlags(); |
| } |
| |
| /// This is the address point. |
| void noteAddressPoint() {} |
| |
| /// Add fields related to the generics of this class declaration. |
| /// TODO: don't add new fields that are implied by the superclass |
| /// fields. e.g., if B<T> extends A<T>, the witness for T in A's |
| /// section should be enough. |
| template <class... T> |
| void addGenericFields(NominalTypeDecl *typeDecl, Type type, |
| T &&...args) { |
| // The archetype order here needs to be consistent with |
| // NominalTypeDescriptorBase::addGenericParams. |
| |
| // Note that we intentionally don't std::forward 'args'. |
| asImpl().noteStartOfGenericRequirements(args...); |
| |
| GenericTypeRequirements requirements(IGM, typeDecl); |
| if (requirements.empty()) return; |
| |
| auto subs = type->castTo<BoundGenericType>() |
| ->gatherAllSubstitutions(IGM.getSwiftModule(), nullptr); |
| requirements.enumerateFulfillments(IGM, subs, |
| [&](unsigned reqtIndex, CanType argType, |
| Optional<ProtocolConformanceRef> conf) { |
| if (conf) { |
| asImpl().addGenericWitnessTable(argType, *conf, args...); |
| } else { |
| asImpl().addGenericArgument(argType, args...); |
| } |
| }); |
| |
| asImpl().noteEndOfGenericRequirements(args...); |
| } |
| |
| template <class... T> |
| void noteStartOfGenericRequirements(T &&...args) {} |
| |
| template <class... T> |
| void noteEndOfGenericRequirements(T &&...args) {} |
| }; |
| |
| } // end namespace irgen |
| } // end namespace swift |
| |
| #endif |