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af68435d90
The buffer of global arrays could already be statically initialized. The missing piece was the array itself, which is basically a reference to the array buffer. For example: ``` var a = [1, 2, 3] ``` ends up in two statically initialized globals: 1. the array buffer, which contains the elements 2. the variable `a` which is a single reference (= pointer) of the array buffer This optimization removes the need for lazy initialization of such variables. rdar://127757554
101 lines
3.0 KiB
Swift
101 lines
3.0 KiB
Swift
//===--- GlobalVariable.swift - Defines the GlobalVariable class ----------===//
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//
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// This source file is part of the Swift.org open source project
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//
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// Copyright (c) 2014 - 2021 Apple Inc. and the Swift project authors
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// Licensed under Apache License v2.0 with Runtime Library Exception
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//
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// See https://swift.org/LICENSE.txt for license information
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// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
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//
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//===----------------------------------------------------------------------===//
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import Basic
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import SILBridging
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final public class GlobalVariable : CustomStringConvertible, HasShortDescription, Hashable {
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public var varDecl: VarDecl? {
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VarDecl(bridged: bridged.getDecl())
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}
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public var name: StringRef {
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return StringRef(bridged: bridged.getName())
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}
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public var description: String {
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return String(taking: bridged.getDebugDescription())
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}
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public var shortDescription: String { name.string }
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public var isLet: Bool { bridged.isLet() }
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/// True, if the linkage of the global variable indicates that it is visible outside the current
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/// compilation unit and therefore not all of its uses are known.
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///
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/// For example, `public` linkage.
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public var isPossiblyUsedExternally: Bool {
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return bridged.isPossiblyUsedExternally()
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}
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/// True, if the linkage of the global indicates that it has a definition outside the
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/// current compilation unit.
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///
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/// For example, `public_external` linkage.
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public var isAvailableExternally: Bool {
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return bridged.isAvailableExternally()
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}
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public var staticInitializerInstructions: InstructionList? {
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if let firstStaticInitInst = bridged.getFirstStaticInitInst().instruction {
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return InstructionList(first: firstStaticInitInst)
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}
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return nil
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}
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public var staticInitValue: SingleValueInstruction? {
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if let staticInitInsts = staticInitializerInstructions {
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return staticInitInsts.reversed().first! as? SingleValueInstruction
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}
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return nil
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}
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/// True if the global's linkage and resilience expansion allow the global
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/// to be initialized statically.
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public var canBeInitializedStatically: Bool {
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return bridged.canBeInitializedStatically()
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}
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public var mustBeInitializedStatically: Bool {
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return bridged.mustBeInitializedStatically()
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}
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public static func ==(lhs: GlobalVariable, rhs: GlobalVariable) -> Bool {
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lhs === rhs
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}
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public func hash(into hasher: inout Hasher) {
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hasher.combine(ObjectIdentifier(self))
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}
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public var bridged: BridgedGlobalVar { BridgedGlobalVar(SwiftObject(self)) }
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}
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// Bridging utilities
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extension BridgedGlobalVar {
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public var globalVar: GlobalVariable { obj.getAs(GlobalVariable.self) }
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public var optional: OptionalBridgedGlobalVar {
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OptionalBridgedGlobalVar(obj: self.obj)
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}
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}
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extension OptionalBridgedGlobalVar {
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public var globalVar: GlobalVariable? { obj.getAs(GlobalVariable.self) }
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public static var none: OptionalBridgedGlobalVar {
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OptionalBridgedGlobalVar(obj: nil)
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}
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}
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