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//===--- SILDefaultWitnessTable.h -------------------------------*- C++ -*-===//
// This source file is part of the 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 for license information
// See for the list of Swift project authors
// This file defines the SILDefaultWitnessTable class, which is used to provide
// default implementations of protocol requirements for resilient protocols,
// allowing IRGen to generate the appropriate metadata so that the runtime can
// insert those requirements to witness tables that were emitted prior to the
// requirement being added.
#include "swift/SIL/SILAllocated.h"
#include "swift/SIL/SILDeclRef.h"
#include "swift/SIL/SILFunction.h"
#include "swift/SIL/SILWitnessTable.h"
#include "llvm/ADT/ilist_node.h"
#include "llvm/ADT/ilist.h"
#include <string>
namespace swift {
class ProtocolDecl;
class SILFunction;
class SILModule;
/// A mapping from each requirement of a protocol to the SIL-level entity
/// satisfying the requirement for conformances which do not explicitly
/// provide a witness.
class SILDefaultWitnessTable : public llvm::ilist_node<SILDefaultWitnessTable>,
public SILAllocated<SILDefaultWitnessTable>
/// A default witness table entry describing the default witness for a
/// requirement.
using Entry = SILWitnessTable::Entry;
/// The module which contains the SILDefaultWitnessTable.
SILModule &Mod;
/// The linkage of the witness table.
SILLinkage Linkage;
/// The protocol declaration to which this default witness table applies.
const ProtocolDecl *Protocol;
/// The minimum size of a valid witness table conforming to this protocol,
/// with all resilient default requirements omitted.
unsigned MinimumWitnessTableSizeInWords;
/// The various witnesses containing in this default witness table.
MutableArrayRef<Entry> Entries;
/// Temporary state while SILGen is emitting a default witness table.
/// We can never have a true declaration since there's no way to reference
/// the default witness table from outside its defining translation unit.
bool IsDeclaration;
/// Private constructor for making SILDefaultWitnessTable declarations.
SILDefaultWitnessTable(SILModule &M, SILLinkage Linkage,
const ProtocolDecl *Protocol);
/// Private constructor for making SILDefaultWitnessTable definitions.
SILDefaultWitnessTable(SILModule &M, SILLinkage Linkage,
const ProtocolDecl *Protocol,
ArrayRef<Entry> entries);
void addDefaultWitnessTable();
/// Create a new SILDefaultWitnessTable declaration.
static SILDefaultWitnessTable *create(SILModule &M, SILLinkage Linkage,
const ProtocolDecl *Protocol);
/// Create a new SILDefaultWitnessTable definition with the given entries.
static SILDefaultWitnessTable *create(SILModule &M, SILLinkage Linkage,
const ProtocolDecl *Protocol,
ArrayRef<Entry> entries);
/// Get a name that uniquely identifies this default witness table.
/// Note that this is /not/ valid as a symbol name; it is only guaranteed to
/// be unique among default witness tables, not all symbols.
std::string getUniqueName() const;
/// Get the linkage of the default witness table.
SILLinkage getLinkage() const { return Linkage; }
/// Set the linkage of the default witness table.
void setLinkage(SILLinkage l) { Linkage = l; }
void convertToDefinition(ArrayRef<Entry> entries);
/// Return true if this is a declaration with no body.
bool isDeclaration() const { return IsDeclaration; }
/// Return the AST ProtocolDecl this default witness table is associated with.
const ProtocolDecl *getProtocol() const { return Protocol; }
/// Clears methods in witness entries.
/// \p predicate Returns true if the passed entry should be set to null.
template <typename Predicate> void clearMethods_if(Predicate predicate) {
for (Entry &entry : Entries) {
if (!entry.isValid())
if (entry.getKind() != SILWitnessTable::Method)
auto *MW = entry.getMethodWitness().Witness;
if (MW && predicate(MW)) {
/// Return all of the default witness table entries.
ArrayRef<Entry> getEntries() const { return Entries; }
/// Verify that the default witness table is well-formed.
void verify(const SILModule &M) const;
/// Print the default witness table.
void print(llvm::raw_ostream &OS, bool Verbose = false) const;
/// Dump the default witness table to stderr.
void dump() const;
} // end swift namespace
// ilist_traits for SILDefaultWitnessTable
namespace llvm {
template <>
struct ilist_traits<::swift::SILDefaultWitnessTable> :
public ilist_node_traits<::swift::SILDefaultWitnessTable> {
using SILDefaultWitnessTable = ::swift::SILDefaultWitnessTable;
static void deleteNode(SILDefaultWitnessTable *WT) { WT->~SILDefaultWitnessTable(); }
void createNode(const SILDefaultWitnessTable &);
} // end llvm namespace