Files
swift-mirror/lib/IRGen/EnumMetadataLayout.h
John McCall cd8c2a47d4 Refactor metadata layout to allow non-pointer-sized
fields and reduce boilerplate.  NFC.

Swift SVN r16877
2014-04-26 07:00:55 +00:00

94 lines
2.7 KiB
C++

//===--- EnumMetadataLayout.h - CRTP for enum metadata ------*- C++ -*-===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2015 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See http://swift.org/LICENSE.txt for license information
// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
//
// A CRTP class useful for laying out enum metadata.
//
//===----------------------------------------------------------------------===//
#ifndef SWIFT_IRGEN_ENUMMETADATALAYOUT_H
#define SWIFT_IRGEN_ENUMMETADATALAYOUT_H
#include "MetadataLayout.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 EnumMetadataLayout : public MetadataLayout<Impl> {
typedef MetadataLayout<Impl> super;
protected:
using super::IGM;
using super::asImpl;
/// The Enum.
EnumDecl *const Target;
EnumMetadataLayout(IRGenModule &IGM, EnumDecl *target)
: super(IGM), Target(target) {}
public:
void layout() {
// Metadata header.
super::layout();
// EnumMetadata header.
asImpl().addNominalTypeDescriptor();
asImpl().addParentMetadataRef();
// If changing this layout, you must update the magic number in
// emitParentMetadataRef.
// Instantiation-specific.
if (auto generics = Target->getGenericParamsOfContext()) {
asImpl().addGenericFields(*generics);
}
}
};
/// An "implementation" of EnumMetadataLayout 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 EnumMetadataLayout<Impl> {
typedef EnumMetadataLayout<Impl> super;
protected:
Size NextOffset = Size(0);
EnumMetadataScanner(IRGenModule &IGM, EnumDecl *target)
: super(IGM, target) {}
public:
void addMetadataFlags() { addPointer(); }
void addValueWitnessTable() { addPointer(); }
void addNominalTypeDescriptor() { addPointer(); }
void addParentMetadataRef() { addPointer(); }
void addGenericArgument(ArchetypeType *argument) { addPointer(); }
void addGenericWitnessTable(ArchetypeType *argument,
ProtocolDecl *protocol) {
addPointer();
}
private:
void addPointer() {
NextOffset += super::IGM.getPointerSize();
}
};
} // end namespace irgen
} // end namespace swift
#endif