Files
swift-mirror/include/swift/SIL/FormalLinkage.h
Slava Pestov b49a4525c3 SIL: Only give type metadata public linkage if -sil-serialize-all is on
Otherwise, any types referenced from transparent functions must be
public or @_versioned.
2016-03-28 14:14:50 -07:00

101 lines
3.6 KiB
C++

//===--- FormalLinkage.h - Formal linkage of types and decls ----*- C++ -*-===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2016 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
//
//===----------------------------------------------------------------------===//
#ifndef SWIFT_SIL_FORMALLINKAGE_H
#define SWIFT_SIL_FORMALLINKAGE_H
namespace swift {
class CanType;
class NormalProtocolConformance;
class ValueDecl;
enum class SILLinkage : unsigned char;
enum ForDefinition_t : bool;
// Bits useful in defining the below.
enum {
// Bottom bit is uniqueness.
FormalLinkage_Unique = 0x0,
FormalLinkage_NonUnique = 0x1,
// Higher bits are visibility, with greater values being more
// restrictive.
FormalLinkage_Public = 0 << 1,
FormalLinkage_Hidden = 1 << 1,
FormalLinkage_Private = 2 << 1,
};
/// Formal linkage is a property of types and declarations that
/// informs, but is not completely equivalent to, the linkage of
/// symbols corresponding to those types and declarations.
///
/// Forms a semilattice with ^ as the meet operator.
enum class FormalLinkage {
/// This entity is visible in multiple Swift modules and has a
/// unique file that is known to define it.
PublicUnique = FormalLinkage_Public | FormalLinkage_Unique,
/// This entity is visible in multiple Swift modules, but does not
/// have a unique file that is known to define it.
PublicNonUnique = FormalLinkage_Public | FormalLinkage_NonUnique,
/// This entity is visible in only a single Swift module and has a
/// unique file that is known to define it.
HiddenUnique = FormalLinkage_Hidden | FormalLinkage_Unique,
/// This entity is visible in only a single Swift module but does not
/// have a unique file that is known to define it.
HiddenNonUnique = FormalLinkage_Hidden | FormalLinkage_NonUnique,
/// This entity is visible in only a single Swift file.
//
// In reality, these are by definition unique, but we use the
// non-unique flag to make merging more efficient.
Private = FormalLinkage_Private | FormalLinkage_NonUnique,
/// The top of the semilattice: (a ^ Top) == a.
Top = PublicUnique,
/// The bottom of the semilattice: (a ^ Bottom) == Bottom.
Bottom = Private,
};
/// Merge two linkages to get the more restrictive.
inline FormalLinkage operator^(FormalLinkage lhs, FormalLinkage rhs) {
// Semantically, we want the more restrictive visibility; if that's
// private, it's unique, and otherwise it's non-unique if either is
// non-unique. This is more efficient if we define away the
// special case for private by representing Private as non-unique.
if (lhs < rhs) {
return FormalLinkage(unsigned(rhs) |
(unsigned(lhs) & FormalLinkage_NonUnique));
} else {
return FormalLinkage(unsigned(lhs) |
(unsigned(rhs) & FormalLinkage_NonUnique));
}
}
inline FormalLinkage &operator^=(FormalLinkage &lhs, FormalLinkage rhs) {
return (lhs = lhs ^ rhs);
}
FormalLinkage getTypeLinkage(CanType type);
FormalLinkage getDeclLinkage(const ValueDecl *decl);
SILLinkage getSILLinkage(FormalLinkage linkage,
ForDefinition_t forDefinition);
SILLinkage
getLinkageForProtocolConformance(const NormalProtocolConformance *C,
ForDefinition_t definition);
} // end swift namespace
#endif