Files
swift-mirror/lib/AST/FeatureSet.h
Michael Gottesman 3ff9463957 Make Feature a struct enum so we can put methods on it.
Just noticed this as I was looking at making other changes.
2025-04-05 10:08:29 +01:00

77 lines
2.5 KiB
C++

//===--- FeatureSet.h - Language feature support ----------------*- C++ -*-===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2024 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
//
//===----------------------------------------------------------------------===//
#ifndef SWIFT_AST_FEATURES_H
#define SWIFT_AST_FEATURES_H
#include "swift/AST/Decl.h"
#include "swift/Basic/Feature.h"
#include "swift/Basic/FixedBitSet.h"
namespace swift {
using BasicFeatureSet =
FixedBitSet<Feature::getNumFeatures(), Feature::InnerKind>;
class FeatureSet {
BasicFeatureSet required;
// Stored inverted: index i actually represents
// Feature(numFeatures() - i)
//
// This is the easiest way of letting us iterate from largest to
// smallest, i.e. from the newest to the oldest feature, which is
// the order in which we need to emit #if clauses.
using SuppressibleFeatureSet = FixedBitSet<Feature::getNumFeatures(), size_t>;
SuppressibleFeatureSet suppressible;
public:
class SuppressibleGenerator {
SuppressibleFeatureSet::iterator i, e;
friend class FeatureSet;
SuppressibleGenerator(const SuppressibleFeatureSet &set)
: i(set.begin()), e(set.end()) {}
public:
bool empty() const { return i == e; }
Feature next() { return Feature(Feature::getNumFeatures() - *i++); }
};
bool empty() const { return required.empty() && suppressible.empty(); }
bool hasAnyRequired() const { return !required.empty(); }
const BasicFeatureSet &requiredFeatures() const { return required; }
bool hasAnySuppressible() const { return !suppressible.empty(); }
SuppressibleGenerator generateSuppressibleFeatures() const {
return SuppressibleGenerator(suppressible);
}
enum InsertOrRemove : bool { Insert = true, Remove = false };
void collectFeaturesUsed(Decl *decl, InsertOrRemove operation);
private:
void collectRequiredFeature(Feature feature, InsertOrRemove operation);
void collectSuppressibleFeature(Feature feature, InsertOrRemove operation);
};
/// Get the set of features that are uniquely used by this declaration, and are
/// not part of the enclosing context.
FeatureSet getUniqueFeaturesUsed(Decl *decl);
bool usesFeatureIsolatedDeinit(const Decl *decl);
} // end namespace swift
#endif /* SWIFT_AST_FEATURES_H */