mirror of
https://github.com/apple/swift.git
synced 2025-12-14 20:36:38 +01:00
137 lines
3.8 KiB
C++
137 lines
3.8 KiB
C++
//===--- StructMetadataVisitor.h - CRTP for struct 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 laying out struct metadata.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef SWIFT_IRGEN_STRUCTMETADATALAYOUT_H
|
|
#define SWIFT_IRGEN_STRUCTMETADATALAYOUT_H
|
|
|
|
#include "Field.h"
|
|
#include "NominalMetadataVisitor.h"
|
|
#include "swift/AST/IRGenOptions.h"
|
|
|
|
namespace swift {
|
|
namespace irgen {
|
|
|
|
/// A CRTP class for laying out struct metadata.
|
|
///
|
|
/// This produces an object corresponding to the StructMetadata type.
|
|
/// It does not itself doing anything special for metadata templates.
|
|
template <class Impl> class StructMetadataVisitor
|
|
: public NominalMetadataVisitor<Impl> {
|
|
using super = NominalMetadataVisitor<Impl>;
|
|
|
|
protected:
|
|
using super::IGM;
|
|
using super::asImpl;
|
|
|
|
/// The struct.
|
|
StructDecl *const Target;
|
|
|
|
StructMetadataVisitor(IRGenModule &IGM, StructDecl *target)
|
|
: super(IGM), Target(target) {}
|
|
|
|
public:
|
|
|
|
void embeddedLayout() {
|
|
// The embedded layout consists of:
|
|
// -1 : vwt
|
|
// 0 : metadata flags
|
|
super::layout();
|
|
}
|
|
|
|
void layout() {
|
|
static_assert(MetadataAdjustmentIndex::ValueType == 2,
|
|
"Adjustment index must be synchronized with this layout");
|
|
|
|
asImpl().addLayoutStringPointer();
|
|
|
|
// Metadata header.
|
|
super::layout();
|
|
|
|
// StructMetadata 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);
|
|
|
|
// Struct field offsets.
|
|
asImpl().noteStartOfFieldOffsets();
|
|
for (VarDecl *prop : Target->getStoredProperties()) {
|
|
if (isExportableField(prop))
|
|
asImpl().addFieldOffset(prop);
|
|
}
|
|
|
|
asImpl().noteEndOfFieldOffsets();
|
|
|
|
if (asImpl().hasTrailingFlags())
|
|
asImpl().addTrailingFlags();
|
|
}
|
|
|
|
// Note the start of the field offset vector.
|
|
void noteStartOfFieldOffsets() {}
|
|
|
|
// Note the end of the field offset vector.
|
|
void noteEndOfFieldOffsets() {}
|
|
|
|
bool hasTrailingFlags() {
|
|
return Target->isGenericContext() &&
|
|
IGM.shouldPrespecializeGenericMetadata();
|
|
}
|
|
};
|
|
|
|
/// An "implementation" of StructMetadataVisitor that just scans through
|
|
/// the metadata layout, maintaining the offset of the next field.
|
|
template <class Impl>
|
|
class StructMetadataScanner : public StructMetadataVisitor<Impl> {
|
|
using super = StructMetadataVisitor<Impl>;
|
|
|
|
protected:
|
|
Size NextOffset = Size(0);
|
|
|
|
StructMetadataScanner(IRGenModule &IGM, StructDecl *target)
|
|
: super(IGM, target) {}
|
|
|
|
public:
|
|
void addMetadataFlags() { addPointer(); }
|
|
void addLayoutStringPointer() { addPointer(); }
|
|
void addValueWitnessTable() { addPointer(); }
|
|
void addNominalTypeDescriptor() { addPointer(); }
|
|
void addFieldOffset(VarDecl *) { addInt32(); }
|
|
void addGenericRequirement(GenericRequirement requirement) { addPointer(); }
|
|
void noteStartOfTypeSpecificMembers() {}
|
|
|
|
void noteEndOfFieldOffsets() {
|
|
NextOffset = NextOffset.roundUpToAlignment(super::IGM.getPointerAlignment());
|
|
}
|
|
|
|
void addTrailingFlags() { addInt64(); }
|
|
|
|
private:
|
|
void addPointer() {
|
|
NextOffset += super::IGM.getPointerSize();
|
|
}
|
|
void addInt32() { NextOffset += Size(4); }
|
|
void addInt64() { NextOffset += Size(8); }
|
|
};
|
|
|
|
} // end namespace irgen
|
|
} // end namespace swift
|
|
|
|
#endif
|