mirror of
https://github.com/apple/swift.git
synced 2025-12-14 20:36:38 +01:00
5519749ade
Another thing that will be necessary for correctness with compositions of parameterized protocols.
113 lines
3.4 KiB
C++
113 lines
3.4 KiB
C++
//===--- ExistentialLayout.h - Existential type decomposition ---*- 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 defines the ExistentialLayout struct.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef SWIFT_EXISTENTIAL_LAYOUT_H
|
|
#define SWIFT_EXISTENTIAL_LAYOUT_H
|
|
|
|
#include "swift/Basic/ArrayRefView.h"
|
|
#include "swift/AST/ASTContext.h"
|
|
#include "swift/AST/Types.h"
|
|
|
|
namespace swift {
|
|
class ProtocolDecl;
|
|
class ProtocolType;
|
|
class ProtocolCompositionType;
|
|
|
|
struct ExistentialLayout {
|
|
enum Kind { Class, Error, Opaque };
|
|
|
|
ExistentialLayout() {
|
|
hasExplicitAnyObject = false;
|
|
containsNonObjCProtocol = false;
|
|
containsParameterized = false;
|
|
}
|
|
|
|
ExistentialLayout(CanProtocolType type);
|
|
ExistentialLayout(CanProtocolCompositionType type);
|
|
ExistentialLayout(CanParameterizedProtocolType type);
|
|
|
|
/// The explicit superclass constraint, if any.
|
|
Type explicitSuperclass;
|
|
|
|
/// Whether the existential contains an explicit '& AnyObject' constraint.
|
|
bool hasExplicitAnyObject : 1;
|
|
|
|
/// Whether any protocol members are non-@objc.
|
|
bool containsNonObjCProtocol : 1;
|
|
|
|
/// Whether any protocol members are parameterized.s
|
|
bool containsParameterized : 1;
|
|
|
|
/// Return the kind of this existential (class/error/opaque).
|
|
Kind getKind() {
|
|
if (requiresClass())
|
|
return Kind::Class;
|
|
if (isErrorExistential())
|
|
return Kind::Error;
|
|
|
|
// The logic here is that opaque is the complement of class + error,
|
|
// i.e. we don't have more concrete information guiding the layout
|
|
// and it doesn't fall into the special-case Error representation.
|
|
return Kind::Opaque;
|
|
}
|
|
|
|
bool isAnyObject() const;
|
|
|
|
bool isObjC() const {
|
|
// FIXME: Does the superclass have to be @objc?
|
|
return ((explicitSuperclass ||
|
|
hasExplicitAnyObject ||
|
|
!getProtocols().empty()) &&
|
|
!containsNonObjCProtocol);
|
|
}
|
|
|
|
/// Whether the existential requires a class, either via an explicit
|
|
/// '& AnyObject' member or because of a superclass or protocol constraint.
|
|
bool requiresClass() const;
|
|
|
|
/// Returns the existential's superclass, if any; this is either an explicit
|
|
/// superclass term in a composition type, or the superclass of one of the
|
|
/// protocols.
|
|
Type getSuperclass() const;
|
|
|
|
/// Does this existential contain the Error protocol?
|
|
bool isExistentialWithError(ASTContext &ctx) const;
|
|
|
|
/// Does this existential consist of an Error protocol only with no other
|
|
/// constraints?
|
|
bool isErrorExistential() const;
|
|
|
|
ArrayRef<ProtocolDecl*> getProtocols() const & {
|
|
return protocols;
|
|
}
|
|
/// The returned ArrayRef points to internal storage, so
|
|
/// calling this on a temporary is likely to be incorrect.
|
|
ArrayRef<ProtocolDecl*> getProtocols() const && = delete;
|
|
|
|
LayoutConstraint getLayoutConstraint() const;
|
|
|
|
private:
|
|
SmallVector<ProtocolDecl *, 4> protocols;
|
|
|
|
/// Zero or more primary associated type requirements from a
|
|
/// ParameterizedProtocolType
|
|
ArrayRef<Type> sameTypeRequirements;
|
|
};
|
|
|
|
}
|
|
|
|
#endif // SWIFT_EXISTENTIAL_LAYOUT_H
|