Merge pull request swiftlang#298 from rintaro/5.5-syntax-postfixifconfig-sr14929

[5.5] Degyb for nullable PostfixIfConfigExpr.base

Author: rintaro

Sources/SwiftSyntax/gyb_generated/Misc.swift

@@ -1960,6 +1960,6 @@ extension Syntax {
 extension SyntaxParser {
   static func verifyNodeDeclarationHash() -> Bool {
     return String(cString: swiftparse_syntax_structure_versioning_identifier()!) ==
-      "a66df9d44b9128aee3da17e9b0d2aed27ce7ec61"
+      "8ee080f1fdc3f07356b951a1f0c9354704b003f2"
   }
 }

Sources/SwiftSyntax/gyb_generated/SyntaxBuilders.swift

@@ -2962,9 +2962,6 @@ public struct PostfixIfConfigExprSyntaxBuilder {
   }
 
   internal mutating func buildData() -> SyntaxData {
-    if (layout[0] == nil) {
-      layout[0] = RawSyntax.missing(SyntaxKind.expr)
-    }
     if (layout[1] == nil) {
       layout[1] = RawSyntax.missing(SyntaxKind.ifConfigDecl)
     }

Sources/SwiftSyntax/gyb_generated/SyntaxFactory.swift

@@ -1418,9 +1418,9 @@ public enum SyntaxFactory {
     ], length: .zero, presence: .present))
     return ObjcSelectorExprSyntax(data)
   }
-  public static func makePostfixIfConfigExpr(base: ExprSyntax, config: IfConfigDeclSyntax) -> PostfixIfConfigExprSyntax {
+  public static func makePostfixIfConfigExpr(base: ExprSyntax?, config: IfConfigDeclSyntax) -> PostfixIfConfigExprSyntax {
     let layout: [RawSyntax?] = [
-      base.raw,
+      base?.raw,
       config.raw,
     ]
     let raw = RawSyntax.createAndCalcLength(kind: SyntaxKind.postfixIfConfigExpr,
@@ -1432,7 +1432,7 @@ public enum SyntaxFactory {
   public static func makeBlankPostfixIfConfigExpr() -> PostfixIfConfigExprSyntax {
     let data = SyntaxData.forRoot(RawSyntax.create(kind: .postfixIfConfigExpr,
       layout: [
-      RawSyntax.missing(SyntaxKind.expr),
+      nil,
       RawSyntax.missing(SyntaxKind.ifConfigDecl),
     ], length: .zero, presence: .present))
     return PostfixIfConfigExprSyntax(data)

Sources/SwiftSyntax/gyb_generated/syntax_nodes/SyntaxExprNodes.swift

@@ -5275,10 +5275,11 @@ public struct PostfixIfConfigExprSyntax: ExprSyntaxProtocol, SyntaxHashable {
     return Swift.type(of: self)
   }
 
-  public var base: ExprSyntax {
+  public var base: ExprSyntax? {
     get {
       let childData = data.child(at: Cursor.base,
                                  parent: Syntax(self))
+      if childData == nil { return nil }
       return ExprSyntax(childData!)
     }
     set(value) {
@@ -5291,7 +5292,7 @@ public struct PostfixIfConfigExprSyntax: ExprSyntaxProtocol, SyntaxHashable {
   ///                   current `base`, if present.
   public func withBase(
     _ newChild: ExprSyntax?) -> PostfixIfConfigExprSyntax {
-    let raw = newChild?.raw ?? RawSyntax.missing(SyntaxKind.expr)
+    let raw = newChild?.raw
     let newData = data.replacingChild(raw, at: Cursor.base)
     return PostfixIfConfigExprSyntax(newData)
   }
@@ -5321,8 +5322,7 @@ public struct PostfixIfConfigExprSyntax: ExprSyntaxProtocol, SyntaxHashable {
   public func _validateLayout() {
     let rawChildren = Array(RawSyntaxChildren(Syntax(self)))
     assert(rawChildren.count == 2)
-    // Check child #0 child is ExprSyntax 
-    assert(rawChildren[0].raw != nil)
+    // Check child #0 child is ExprSyntax or missing
     if let raw = rawChildren[0].raw {
       let info = rawChildren[0].syntaxInfo
       let absoluteRaw = AbsoluteRawSyntax(raw: raw, info: info)
@@ -5345,7 +5345,7 @@ public struct PostfixIfConfigExprSyntax: ExprSyntaxProtocol, SyntaxHashable {
 extension PostfixIfConfigExprSyntax: CustomReflectable {
   public var customMirror: Mirror {
     return Mirror(self, children: [
-      "base": Syntax(base).asProtocol(SyntaxProtocol.self),
+      "base": base.map(Syntax.init)?.asProtocol(SyntaxProtocol.self) as Any,
       "config": Syntax(config).asProtocol(SyntaxProtocol.self),
     ])
   }