From d88d9b105b49220dd61f484c12884bd5d1c0ca2e Mon Sep 17 00:00:00 2001
From: Gus Cairo <gus.cairo@apple.com>
Date: Tue, 26 Sep 2023 14:23:25 +0100
Subject: [PATCH] Add support for `package` visibility modifier

---
 Documentation/PLUGIN.md                         | 2 ++
 Plugins/SwiftProtobufPlugin/plugin.swift        | 5 +++++
 Sources/protoc-gen-swift/GeneratorOptions.swift | 5 +++++
 3 files changed, 12 insertions(+)

diff --git a/Documentation/PLUGIN.md b/Documentation/PLUGIN.md
index e6b2c7972..09e86811a 100644
--- a/Documentation/PLUGIN.md
+++ b/Documentation/PLUGIN.md
@@ -119,6 +119,8 @@ The possible values for `Visibility` are:
 
 * `Internal` (default): No visibility is set for the types, so they get the
   default internal visibility.
+* `Package` (Swift 5.9 or later required): The visibility on the types is set to
+ `package` so the types will be exposed across the whole Swift package they belong to.
 * `Public`: The visibility on the types is set to `public` so the types will
   be exposed outside the module they are compiled into.
 
diff --git a/Plugins/SwiftProtobufPlugin/plugin.swift b/Plugins/SwiftProtobufPlugin/plugin.swift
index 434db2238..ca846b0a8 100644
--- a/Plugins/SwiftProtobufPlugin/plugin.swift
+++ b/Plugins/SwiftProtobufPlugin/plugin.swift
@@ -37,6 +37,9 @@ struct SwiftProtobufPlugin {
                 case `internal` = "Internal"
                 /// The generated files should have `public` access level.
                 case `public` = "Public"
+                /// The generated files should have `package` access level.
+                /// - Note: Swift 5.9 or later is needed to use this option.
+                case `package` = "Package"
 
                 init?(rawValue: String) {
                     switch rawValue.lowercased() {
@@ -44,6 +47,8 @@ struct SwiftProtobufPlugin {
                         self = .internal
                     case "public":
                         self = .public
+                    case "package":
+                        self = .package
                     default:
                         return nil
                     }
diff --git a/Sources/protoc-gen-swift/GeneratorOptions.swift b/Sources/protoc-gen-swift/GeneratorOptions.swift
index 69ecdb869..f8f8dced4 100644
--- a/Sources/protoc-gen-swift/GeneratorOptions.swift
+++ b/Sources/protoc-gen-swift/GeneratorOptions.swift
@@ -33,6 +33,7 @@ class GeneratorOptions {
   enum Visibility {
     case `internal`
     case `public`
+    case `package`
 
     init?(flag: String) {
       switch flag.lowercased() {
@@ -40,6 +41,8 @@ class GeneratorOptions {
         self = .internal
       case "public":
         self = .public
+      case "package":
+        self = .package
       default:
         return nil
       }
@@ -119,6 +122,8 @@ class GeneratorOptions {
       visibilitySourceSnippet = ""
     case .public:
       visibilitySourceSnippet = "public "
+    case .package:
+      visibilitySourceSnippet = "package "
     }
 
     self.implementationOnlyImports = implementationOnlyImports