//===--- Visibility.h - Visibility enumeration and utilities ----*- C++ -*-===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

///

/// \file

/// Defines the clang::Visibility enumeration and various utility

/// functions.

///

//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_BASIC_VISIBILITY_H

#define LLVM_CLANG_BASIC_VISIBILITY_H

#include "clang/Basic/Linkage.h"

#include <cassert>

#include <cstdint>

namespace clang {

/// Describes the different kinds of visibility that a declaration

/// may have.

///

/// Visibility determines how a declaration interacts with the dynamic

/// linker.  It may also affect whether the symbol can be found by runtime

/// symbol lookup APIs.

///

/// Visibility is not described in any language standard and

/// (nonetheless) sometimes has odd behavior.  Not all platforms

/// support all visibility kinds.

enum Visibility {

  /// Objects with "hidden" visibility are not seen by the dynamic

  /// linker.

  HiddenVisibility,

  /// Objects with "protected" visibility are seen by the dynamic

  /// linker but always dynamically resolve to an object within this

  /// shared object.

  ProtectedVisibility,

  /// Objects with "default" visibility are seen by the dynamic linker

  /// and act like normal objects.

  DefaultVisibility

};

inline Visibility minVisibility(Visibility L, Visibility R) {

  return L < R ? L : R;

}

class LinkageInfo {

  uint8_t linkage_    : 3;

  uint8_t visibility_ : 2;

  uint8_t explicit_   : 1;

  void setVisibility(Visibility V, bool E) { visibility_ = V; explicit_ = E; }

public:

  LinkageInfo() : linkage_(ExternalLinkage), visibility_(DefaultVisibility),

                  explicit_(false) {}

  LinkageInfo(Linkage L, Visibility V, bool E)

    : linkage_(L), visibility_(V), explicit_(E) {

    assert(getLinkage() == L && getVisibility() == V &&

           isVisibilityExplicit() == E && "Enum truncated!");

  }

  static LinkageInfo external() {

    return LinkageInfo();

  }

  static LinkageInfo internal() {

    return LinkageInfo(InternalLinkage, DefaultVisibility, false);

  }

  static LinkageInfo uniqueExternal() {

    return LinkageInfo(UniqueExternalLinkage, DefaultVisibility, false);

  }

  static LinkageInfo none() {

    return LinkageInfo(NoLinkage, DefaultVisibility, false);

  }

  static LinkageInfo visible_none() {

    return LinkageInfo(VisibleNoLinkage, DefaultVisibility, false);

  }

  Linkage getLinkage() const { return (Linkage)linkage_; }

  Visibility getVisibility() const { return (Visibility)visibility_; }

  bool isVisibilityExplicit() const { return explicit_; }

  void setLinkage(Linkage L) { linkage_ = L; }

  void mergeLinkage(Linkage L) {

    setLinkage(minLinkage(getLinkage(), L));

  }

  void mergeLinkage(LinkageInfo other) {

    mergeLinkage(other.getLinkage());

  }

  void mergeExternalVisibility(Linkage L) {

    Linkage ThisL = getLinkage();

    if (!isExternallyVisible(L)) {

      if (ThisL == VisibleNoLinkage)

        ThisL = NoLinkage;

      else if (ThisL == ExternalLinkage)

        ThisL = UniqueExternalLinkage;

    }

    setLinkage(ThisL);

  }

  void mergeExternalVisibility(LinkageInfo Other) {

    mergeExternalVisibility(Other.getLinkage());

  }

  /// Merge in the visibility 'newVis'.

  void mergeVisibility(Visibility newVis, bool newExplicit) {

    Visibility oldVis = getVisibility();

    // Never increase visibility.

    if (oldVis < newVis)

      return;

    // If the new visibility is the same as the old and the new

    // visibility isn't explicit, we have nothing to add.

    if (oldVis == newVis && 
!newExplicit7.46M
)

      return;

    // Otherwise, we're either decreasing visibility or making our

    // existing visibility explicit.

    setVisibility(newVis, newExplicit);

  }

  void mergeVisibility(LinkageInfo other) {

    mergeVisibility(other.getVisibility(), other.isVisibilityExplicit());

  }

  /// Merge both linkage and visibility.

  void merge(LinkageInfo other) {

    mergeLinkage(other);

    mergeVisibility(other);

  }

  /// Merge linkage and conditionally merge visibility.

  void mergeMaybeWithVisibility(LinkageInfo other, bool withVis) {

    mergeLinkage(other);

    if (withVis) 
mergeVisibility(other)2.78M
;

  }

};

}

#endif // LLVM_CLANG_BASIC_VISIBILITY_H