Support availability overrides

Sources/GRPCProtobuf/Documentation.docc/Articles/Generating-stubs.md

@@ -133,26 +133,35 @@ protoc \
 
 #### Generator options
 
-| Name                      | Possible Values                             | Default    | Description                                              |
-|---------------------------|---------------------------------------------|------------|----------------------------------------------------------|
-| `Visibility`              | `Public`, `Package`, `Internal`             | `Internal` | Access level for generated stubs                         |
-| `Server`                  | `True`, `False`                             | `True`     | Generate server stubs                                    |
-| `Client`                  | `True`, `False`                             | `True`     | Generate client stubs                                    |
-| `FileNaming`              | `FullPath`, `PathToUnderscores`, `DropPath` | `FullPath` | How generated source files should be named. (See below.) |
-| `ProtoPathModuleMappings` |                                             |            | Path to module map `.asciipb` file. (See below.)         |
-| `UseAccessLevelOnImports` | `True`, `False`                             | `False`    | Whether imports should have explicit access levels.      |
-
-The `FileNaming` option has three possible values, for an input of `foo/bar/baz.proto` the following
+| Name                      | Possible Values                             | Default         | Description                                              |
+|---------------------------|---------------------------------------------|-----------------|----------------------------------------------------------|
+| `Visibility`              | `Public`, `Package`, `Internal`             | `Internal`      | Access level for generated stubs                         |
+| `Server`                  | `True`, `False`                             | `True`          | Generate server stubs                                    |
+| `Client`                  | `True`, `False`                             | `True`          | Generate client stubs                                    |
+| `FileNaming`              | `FullPath`, `PathToUnderscores`, `DropPath` | `FullPath`      | How generated source files should be named. †            |
+| `ProtoPathModuleMappings` |                                             |                 | Path to module map `.asciipb` file. ‡                    |
+| `UseAccessLevelOnImports` | `True`, `False`                             | `False`         | Whether imports should have explicit access levels.      |
+| `GRPCModuleName`          |                                             | `GRPCCore`      | The name of the `GRPCCore` module.                       |
+| `GRPCProtobufModuleName`  |                                             | `GRPCProtobuf`  | The name of the `GRPCProtobuf` module.                   |
+| `SwiftProtobufModuleName` |                                             | `SwiftProtobuf` | The name of the `SwiftProtobuf` module.                  |
+| `Availability`            | String, in the form `OS Version`            |                 | Platform availability to use in generated code. §        |
+
+† The `FileNaming` option has three possible values, for an input of `foo/bar/baz.proto` the following
 output file will be generated:
 - `FullPath`: `foo/bar/baz.grpc.swift`.
 - `PathToUnderscores`: `foo_bar_baz.grpc.swift`
 - `DropPath`: `baz.grpc.swift`
 
-The code generator assumes all inputs are generated into the same module, `ProtoPathModuleMappings`
+‡ The code generator assumes all inputs are generated into the same module, `ProtoPathModuleMappings`
 allows you to specify a mapping from `.proto` files to the Swift module they are generated in. This
 allows the code generator to add appropriate imports to your generated stubs. This is described in
 more detail in the [SwiftProtobuf documentation](https://github.com/apple/swift-protobuf/blob/main/Documentation/PLUGIN.md).
 
+§ If unspecified the following availability is used: macOS 15, iOS 18, tvOS 18,
+watchOS 11, visionOS 2. The `Availability` option may be specified multiple
+times, where each value is a space delimited pair of platform and version, e.g.
+`Availability=macOS 15.0`.
+
 #### Building the protoc plugin
 
 > The version of `protoc-gen-grpc-swift` you use mustn't be newer than the version of

Sources/GRPCProtobufCodeGen/ProtobufCodeGenerator.swift

@@ -29,7 +29,8 @@ package struct ProtobufCodeGenerator {
   package func generateCode(
     fileDescriptor: FileDescriptor,
     protoFileModuleMappings: ProtoFileToModuleMappings,
-    extraModuleImports: [String]
+    extraModuleImports: [String],
+    availabilityOverrides: [(os: String, version: String)] = []
   ) throws -> String {
     let parser = ProtobufCodeGenParser(
       protoFileModuleMappings: protoFileModuleMappings,
@@ -46,6 +47,17 @@ package struct ProtobufCodeGenerator {
       indentation: self.config.indentation
     )
     codeGeneratorConfig.grpcCoreModuleName = self.config.moduleNames.grpcCore
+
+    if availabilityOverrides.isEmpty {
+      codeGeneratorConfig.availability = .default
+    } else {
+      codeGeneratorConfig.availability = .custom(
+        availabilityOverrides.map { (os, version) in
+          .init(os: os, version: version)
+        }
+      )
+    }
+
     let codeGenerator = GRPCCodeGen.CodeGenerator(config: codeGeneratorConfig)
 
     let codeGenerationRequest = try parser.parse(descriptor: fileDescriptor)

Sources/protoc-gen-grpc-swift/GenerateGRPC.swift

@@ -73,7 +73,8 @@ final class GenerateGRPC: SwiftProtobufPluginLibrary.CodeGenerator {
     let contents = try fileGenerator.generateCode(
       fileDescriptor: descriptor,
       protoFileModuleMappings: options.protoToModuleMappings,
-      extraModuleImports: options.extraModuleImports
+      extraModuleImports: options.extraModuleImports,
+      availabilityOverrides: options.availabilityOverrides
     )
 
     try outputs.add(fileName: fileName, contents: contents)

Sources/protoc-gen-grpc-swift/Options.swift

@@ -52,6 +52,7 @@ struct GeneratorOptions {
   private(set) var protoToModuleMappings = ProtoFileToModuleMappings()
   private(set) var fileNaming = FileNaming.fullPath
   private(set) var extraModuleImports: [String] = []
+  private(set) var availabilityOverrides: [(os: String, version: String)] = []
 
   private(set) var config: ProtobufCodeGenerator.Config = .defaults
 
@@ -130,6 +131,18 @@ struct GeneratorOptions {
           throw GenerationError.invalidParameterValue(name: pair.key, value: pair.value)
         }
 
+      case "Availability":
+        if !pair.value.isEmpty {
+          let parts = pair.value.split(separator: " ", maxSplits: 1)
+          if parts.count == 2 {
+            self.availabilityOverrides.append((os: String(parts[0]), version: String(parts[1])))
+          } else {
+            throw GenerationError.invalidParameterValue(name: pair.key, value: pair.value)
+          }
+        } else {
+          throw GenerationError.invalidParameterValue(name: pair.key, value: pair.value)
+        }
+
       case "ReflectionData":
         throw GenerationError.unsupportedParameter(
           name: pair.key,

Tests/GRPCProtobufCodeGenTests/ProtobufCodeGeneratorTests.swift

@@ -25,8 +25,38 @@ struct ProtobufCodeGeneratorTests {
     static let descriptorSetName = "test-service"
     static let fileDescriptorName = "test-service"
 
-    @Test("Generate", arguments: [CodeGenerator.Config.AccessLevel.internal])
-    func generate(accessLevel: GRPCCodeGen.CodeGenerator.Config.AccessLevel) throws {
+    enum Availability {
+      case `default`
+      case fooOS
+
+      var override: [(String, String)] {
+        switch self {
+        case .default:
+          return []
+        case .fooOS:
+          return [("fooOS", "42.0")]
+        }
+      }
+
+      var expected: String {
+        switch self {
+        case .default:
+          return "macOS 15.0, iOS 18.0, watchOS 11.0, tvOS 18.0, visionOS 2.0"
+        case .fooOS:
+          return "fooOS 42.0"
+        }
+      }
+    }
+
+    @Test(
+      "Generate",
+      arguments: [CodeGenerator.Config.AccessLevel.internal],
+      [Availability.default, Availability.fooOS]
+    )
+    func generate(
+      accessLevel: GRPCCodeGen.CodeGenerator.Config.AccessLevel,
+      availability: Availability
+    ) throws {
       var config = ProtobufCodeGenerator.Config.defaults
       config.accessLevel = accessLevel
       config.indentation = 2
@@ -44,10 +74,13 @@ struct ProtobufCodeGeneratorTests {
         fatalError()
       }
 
+      let expectedAvailability = availability.expected
+
       let generated = try generator.generateCode(
         fileDescriptor: Self.fileDescriptor,
         protoFileModuleMappings: ProtoFileToModuleMappings(),
-        extraModuleImports: []
+        extraModuleImports: [],
+        availabilityOverrides: availability.override
       )
 
       let expected = """
@@ -70,7 +103,7 @@ struct ProtobufCodeGeneratorTests {
         // MARK: - test.TestService
 
         /// Namespace containing generated types for the "test.TestService" service.
-        @available(macOS 15.0, iOS 18.0, watchOS 11.0, tvOS 18.0, visionOS 2.0, *)
+        @available(\(expectedAvailability), *)
         \(access) enum Test_TestService {
           /// Service descriptor for the "test.TestService" service.
           \(access) static let descriptor = GRPCCore.ServiceDescriptor(fullyQualifiedService: "test.TestService")
@@ -134,15 +167,15 @@ struct ProtobufCodeGeneratorTests {
           }
         }
 
-        @available(macOS 15.0, iOS 18.0, watchOS 11.0, tvOS 18.0, visionOS 2.0, *)
+        @available(\(expectedAvailability), *)
         extension GRPCCore.ServiceDescriptor {
           /// Service descriptor for the "test.TestService" service.
           \(access) static let test_TestService = GRPCCore.ServiceDescriptor(fullyQualifiedService: "test.TestService")
         }
 
         // MARK: test.TestService (server)
 
-        @available(macOS 15.0, iOS 18.0, watchOS 11.0, tvOS 18.0, visionOS 2.0, *)
+        @available(\(expectedAvailability), *)
         extension Test_TestService {
           /// Streaming variant of the service protocol for the "test.TestService" service.
           ///
@@ -404,7 +437,7 @@ struct ProtobufCodeGeneratorTests {
         }
 
         // Default implementation of 'registerMethods(with:)'.
-        @available(macOS 15.0, iOS 18.0, watchOS 11.0, tvOS 18.0, visionOS 2.0, *)
+        @available(\(expectedAvailability), *)
         extension Test_TestService.StreamingServiceProtocol {
           \(access) func registerMethods<Transport>(with router: inout GRPCCore.RPCRouter<Transport>) where Transport: GRPCCore.ServerTransport {
             router.registerHandler(
@@ -455,7 +488,7 @@ struct ProtobufCodeGeneratorTests {
         }
 
         // Default implementation of streaming methods from 'StreamingServiceProtocol'.
-        @available(macOS 15.0, iOS 18.0, watchOS 11.0, tvOS 18.0, visionOS 2.0, *)
+        @available(\(expectedAvailability), *)
         extension Test_TestService.ServiceProtocol {
           \(access) func unary(
             request: GRPCCore.StreamingServerRequest<Test_TestInput>,
@@ -492,7 +525,7 @@ struct ProtobufCodeGeneratorTests {
         }
 
         // Default implementation of methods from 'ServiceProtocol'.
-        @available(macOS 15.0, iOS 18.0, watchOS 11.0, tvOS 18.0, visionOS 2.0, *)
+        @available(\(expectedAvailability), *)
         extension Test_TestService.SimpleServiceProtocol {
           \(access) func unary(
             request: GRPCCore.ServerRequest<Test_TestInput>,
@@ -557,7 +590,7 @@ struct ProtobufCodeGeneratorTests {
 
         // MARK: test.TestService (client)
 
-        @available(macOS 15.0, iOS 18.0, watchOS 11.0, tvOS 18.0, visionOS 2.0, *)
+        @available(\(expectedAvailability), *)
         extension Test_TestService {
           /// Generated client protocol for the "test.TestService" service.
           ///
@@ -816,7 +849,7 @@ struct ProtobufCodeGeneratorTests {
         }
 
         // Helpers providing default arguments to 'ClientProtocol' methods.
-        @available(macOS 15.0, iOS 18.0, watchOS 11.0, tvOS 18.0, visionOS 2.0, *)
+        @available(\(expectedAvailability), *)
         extension Test_TestService.ClientProtocol {
           /// Call the "Unary" method.
           ///
@@ -932,7 +965,7 @@ struct ProtobufCodeGeneratorTests {
         }
 
         // Helpers providing sugared APIs for 'ClientProtocol' methods.
-        @available(macOS 15.0, iOS 18.0, watchOS 11.0, tvOS 18.0, visionOS 2.0, *)
+        @available(\(expectedAvailability), *)
         extension Test_TestService.ClientProtocol {
           /// Call the "Unary" method.
           ///