Files
swift-mirror/lib/IRGen/GenValueWitness.h
John McCall 9bbbe2c418 Update the metadata-initialization ABI:
- Create the value witness table as a separate global object instead
  of concatenating it to the metadata pattern.

- Always pass the metadata to the runtime and let the runtime handle
  instantiating or modifying the value witness table.

- Pass the right layout algorithm version to the runtime; currently
  this is always "Swift 5".

- Create a runtime function to instantiate single-case enums.

Among other things, this makes the copying of the VWT, and any
modifications of it, explicit and in the runtime, which is more
future-proof.
2017-12-21 00:26:37 -05:00

51 lines
1.6 KiB
C++

//===--- GenValueWitness.h - Swift IRGen for value witnesses ----*- 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 provides the private interface to the value witness emission
// code.
//
//===----------------------------------------------------------------------===//
#ifndef SWIFT_IRGEN_GENVALUEWITNESS_H
#define SWIFT_IRGEN_GENVALUEWITNESS_H
#include "swift/Basic/LLVM.h"
namespace llvm {
class Constant;
class Type;
}
namespace swift {
class CanType;
namespace irgen {
class ConstantStructBuilder;
class IRGenModule;
/// True if a type has a generic-parameter-dependent value witness table.
/// Currently, this is true if the size and/or alignment of the type is
/// dependent on its generic parameters.
bool hasDependentValueWitnessTable(IRGenModule &IGM, CanType ty);
/// Emit a value-witness table for the given type.
///
/// \param isPattern - true if the table just serves as an instantiation
/// pattern and does not need to be modifiable in-place (if the type
/// does not have static layout for some reason)
llvm::Constant *emitValueWitnessTable(IRGenModule &IGM, CanType type,
bool isPattern);
}
}
#endif