Introduce @_package attribute

Author: stevapple

CodeGeneration/Sources/SyntaxSupport/KeywordSpec.swift

@@ -67,6 +67,7 @@ public let KEYWORDS: [KeywordSpec] = [
   KeywordSpec("_opaqueReturnTypeOf"),
   KeywordSpec("_optimize"),
   KeywordSpec("_originallyDefinedIn"),
+  KeywordSpec("_package"),
   KeywordSpec("_PackageDescription"),
   KeywordSpec("_private"),
   KeywordSpec("_projectedValueProperty"),

Sources/SwiftParser/Attributes.swift

@@ -43,6 +43,7 @@ extension Parser {
     case _objcRuntimeName
     case _optimize
     case _originallyDefinedIn
+    case _package
     case _private
     case _projectedValueProperty
     case _semantics
@@ -78,6 +79,7 @@ extension Parser {
       case RawTokenKindMatch(._objcRuntimeName): self = ._objcRuntimeName
       case RawTokenKindMatch(._optimize): self = ._optimize
       case RawTokenKindMatch(._originallyDefinedIn): self = ._originallyDefinedIn
+      case RawTokenKindMatch(._package): self = ._package
       case RawTokenKindMatch(._private): self = ._private
       case RawTokenKindMatch(._projectedValueProperty): self = ._projectedValueProperty
       case RawTokenKindMatch(._semantics): self = ._semantics
@@ -116,6 +118,7 @@ extension Parser {
       case ._objcRuntimeName: return .keyword(._objcRuntimeName)
       case ._optimize: return .keyword(._optimize)
       case ._originallyDefinedIn: return .keyword(._originallyDefinedIn)
+      case ._package: return .keyword(._package)
       case ._private: return .keyword(._private)
       case ._projectedValueProperty: return .keyword(._projectedValueProperty)
       case ._semantics: return .keyword(._semantics)
@@ -243,6 +246,15 @@ extension Parser {
       return parseAttribute(argumentMode: .required) { parser in
         return .specializeArguments(parser.parseSpecializeAttributeSpecList())
       }
+    case ._package:
+      return parseAttribute(argumentMode: .required) { parser in
+        // TODO: @_package(...) argument parsing
+        if !parser.at(.rightParen) {
+          return .token(parser.consumeAnyToken())
+        } else {
+          return .token(parser.missingToken(.identifier))
+        }
+      }
     case ._private:
       return parseAttribute(argumentMode: .required) { parser in
         return .underscorePrivateAttributeArguments(parser.parseUnderscorePrivateAttributeArguments())

Sources/SwiftSyntax/generated/Keyword.swift

@@ -85,6 +85,8 @@ public enum Keyword: UInt8, Hashable {
 
   case _originallyDefinedIn
 
+  case _package
+  
   case _PackageDescription
 
   case _private
@@ -655,6 +657,8 @@ public enum Keyword: UInt8, Hashable {
         self = ._effects
       case "_forward": 
         self = ._forward
+      case "_package": 
+        self = ._package
       case "_private": 
         self = ._private
       case "_Trivial": 

gyb_syntax_support/AttributeKinds.py

@@ -708,7 +708,12 @@ def __init__(self, name, swift_name=None):
     SimpleDeclAttribute('runtimeMetadata', 'RuntimeMetadata',
                         OnStruct,  OnClass,
                         ABIBreakingToAdd,  ABIBreakingToRemove,  APIBreakingToAdd,  APIBreakingToRemove,
-                        code=139)
+                        code=139),
+
+    DeclAttribute('_package', 'Package',
+                  OnImport, UserInaccessible,
+                  APIStableToAdd, APIStableToRemove, ABIStableToAdd, ABIStableToRemove, NotSerialized,
+                  code=140),
 ]
 
 # Schema for declaration modifiers: