//===--- IAMInference.h - Import as member inference system -----*- 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 implements support for inferring when globals can be imported as
// members
//
//===----------------------------------------------------------------------===//

#ifndef SWIFT_IMPORTER_IMPORT_AS_MEMBER_INFERENCE_H
#define SWIFT_IMPORTER_IMPORT_AS_MEMBER_INFERENCE_H

#include "SwiftLookupTable.h"

#include "llvm/ADT/Optional.h"
#include "llvm/ADT/StringRef.h"

#include "swift/AST/Identifier.h"

namespace clang {
class Sema;
class NamedDecl;
class TypeDecl;
class FunctionDecl;
}

namespace swift {

// Import As Member -- attempt to import C global functions and variables as
// members on types or instances.

struct IAMOptions {
  // TODO: fine-grained control over how we infer
  static IAMOptions getDefault();
};

enum class IAMAccessorKind : uint8_t { None, Getter, Setter };

/// The result of out inference system
struct IAMResult {
  // The name to import as
  DeclName name = {};

  // If this is a getter/setter, the other accessor
  const clang::FunctionDecl *pairedAccessor = nullptr;

  IAMAccessorKind accessorKind = IAMAccessorKind::None;

  Optional<unsigned> selfIndex = None;

  // The canonical type decl we will import as a member of
  EffectiveClangContext effectiveDC = {};

  static IAMResult infer(ASTContext &, clang::Sema &, const clang::NamedDecl *,
                         IAMOptions = IAMOptions::getDefault());

  IAMResult() = default;

  // Static members
  IAMResult(DeclName declName, EffectiveClangContext dc)
      : name(declName), effectiveDC(dc) {}

  IAMResult(DeclName declName, IAMAccessorKind kind, EffectiveClangContext dc)
      : name(declName), accessorKind(kind), effectiveDC(dc) {}

  // Instance members
  IAMResult(DeclName declName, unsigned selfIdx, EffectiveClangContext dc)
      : name(declName), selfIndex(selfIdx), effectiveDC(dc) {}

  IAMResult(DeclName declName, IAMAccessorKind kind, unsigned selfIdx,
            EffectiveClangContext dc)
      : name(declName), accessorKind(kind), selfIndex(selfIdx),
        effectiveDC(dc) {}

  bool isImportAsMember() const { return bool(effectiveDC); }

  bool isInstanceMember() const {
    return isImportAsMember() && selfIndex.hasValue();
  }

  bool isStaticMember() const {
    return isImportAsMember() && !selfIndex.hasValue();
  }

  bool isPropertyAccessor() const {
    return accessorKind != IAMAccessorKind::None;
  }

  bool isGetter() const {
    return accessorKind == IAMAccessorKind::Getter;
  }

  bool isSetter() const {
    return accessorKind == IAMAccessorKind::Setter;
  }

  bool isInit() const {
    return isStaticMember() && name.getBaseName() == "init";
  }
};
}

#endif // SWIFT_IMPORTER_IMPORT_AS_MEMBER_INFERENCE_H