Split generated code into multiple files

Sources/protoc-gen-swift/EnumGenerator.swift

@@ -113,15 +113,15 @@ class EnumGenerator {
         p.print("]")
     }
 
-    func generateRuntimeSupport(printer p: inout CodePrinter) {
-        p.print(
+    func generateRuntimeSupport(filePrinter fp: inout FilePrinter) {
+        fp.nameProviding.print(
             "",
             "extension \(swiftFullName): \(namer.swiftProtobufModulePrefix)_ProtoNameProviding {"
         )
-        p.withIndentation { p in
+        fp.nameProviding.withIndentation { p in
             generateProtoNameProviding(printer: &p)
         }
-        p.print("}")
+        fp.nameProviding.print("}")
     }
 
     /// Generates the cases or statics (for alias) for the values.

Sources/protoc-gen-swift/FileGenerator.swift

@@ -23,8 +23,7 @@ class FileGenerator {
     private let generatorOptions: GeneratorOptions
     private let namer: SwiftProtobufNamer
 
-    var outputFilename: String {
-        let ext = ".pb.swift"
+    func outputFilename(_ ext: String) -> String {
         let pathParts = splitPath(pathname: fileDescriptor.name)
         switch generatorOptions.outputNaming {
         case .fullPath:
@@ -52,7 +51,7 @@ class FileGenerator {
 
     /// Generate, if `errorString` gets filled in, then report error instead of using
     /// what written into `printer`.
-    func generateOutputFile(printer p: inout CodePrinter, errorString: inout String?) {
+    func generateOutputFile(filePrinter fp: inout FilePrinter, errorString: inout String?) {
         guard
             fileDescriptor.options.swiftPrefix.isEmpty
                 || isValidSwiftIdentifier(
@@ -64,20 +63,23 @@ class FileGenerator {
                 "\(fileDescriptor.name) has an 'swift_prefix' that isn't a valid Swift identifier (\(fileDescriptor.options.swiftPrefix))."
             return
         }
-        p.print(
-            """
-            // DO NOT EDIT.
-            // swift-format-ignore-file
-            // swiftlint:disable all
-            //
-            // Generated by the Swift generator plugin for the protocol buffer compiler.
-            // Source: \(fileDescriptor.name)
-            //
-            // For information on using the generated types, please see the documentation:
-            //   https://github.com/apple/swift-protobuf/
+
+        fp.forEach { p in
+            p.print(
+                """
+                // DO NOT EDIT.
+                // swift-format-ignore-file
+                // swiftlint:disable all
+                //
+                // Generated by the Swift generator plugin for the protocol buffer compiler.
+                // Source: \(fileDescriptor.name)
+                //
+                // For information on using the generated types, please see the documentation:
+                //   https://github.com/apple/swift-protobuf/
 
-            """
-        )
+                """
+            )
+        }
 
         // Attempt to bring over the comments at the top of the .proto file as
         // they likely contain copyrights/preamble/etc.
@@ -106,7 +108,7 @@ class FileGenerator {
             if !comments.isEmpty {
                 // If the was a leading or tailing comment it won't have a blank
                 // line, after it, so ensure there is one.
-                p.print(comments, newlines: !comments.hasSuffix("\n\n"))
+                fp.main.print(comments, newlines: !comments.hasSuffix("\n\n"))
             }
         }
 
@@ -115,17 +117,23 @@ class FileGenerator {
 
         var hasImports = false
         if fileDescriptor.needsFoundationImport {
-            p.print("\(generatorOptions.importDirective.snippet) Foundation")
+            fp.forEach { p in
+                p.print("\(generatorOptions.importDirective.snippet) Foundation")
+            }
             hasImports = true
         }
 
         if fileDescriptor.isBundledProto {
-            p.print(
-                "// 'import \(namer.swiftProtobufModuleName)' suppressed, this proto file is meant to be bundled in the runtime."
-            )
+            fp.forEach { p in
+                p.print(
+                    "// 'import \(namer.swiftProtobufModuleName)' suppressed, this proto file is meant to be bundled in the runtime."
+                )
+            }
             hasImports = true
         } else if fileDefinesTypes {
-            p.print("\(generatorOptions.importDirective.snippet) \(namer.swiftProtobufModuleName)")
+            fp.forEach { p in
+                p.print("\(generatorOptions.importDirective.snippet) \(namer.swiftProtobufModuleName)")
+            }
             hasImports = true
         }
 
@@ -135,25 +143,31 @@ class FileGenerator {
             reexportPublicImports: generatorOptions.visibility != .internal
         )
         if !neededImports.isEmpty {
-            if hasImports {
-                p.print()
+            fp.forEach { p in
+                if hasImports {
+                    p.print()
+                }
+                p.print(neededImports)
             }
-            p.print(neededImports)
             hasImports = true
         }
 
         // If there is nothing to generate, then just record that and be done (usually means
         // there just was one or more services).
         guard fileDefinesTypes else {
-            if hasImports {
-                p.print()
+            fp.forEach { p in
+                if hasImports {
+                    p.print()
+                }
+                p.print("// This file contained no messages, enums, or extensions.")
             }
-            p.print("// This file contained no messages, enums, or extensions.")
             return
         }
 
-        p.print()
-        generateVersionCheck(printer: &p)
+        fp.forEach { p in
+            p.print()
+            generateVersionCheck(printer: &p)
+        }
 
         let extensionSet =
             ExtensionSetGenerator(
@@ -178,54 +192,56 @@ class FileGenerator {
         }
 
         for e in enums {
-            e.generateMainEnum(printer: &p)
+            e.generateMainEnum(printer: &fp.main)
         }
 
         for m in messages {
-            m.generateMainStruct(printer: &p, parent: nil, errorString: &errorString)
+            m.generateMainStruct(printer: &fp.main, parent: nil, errorString: &errorString)
         }
 
         if !extensionSet.isEmpty {
             let pathParts = splitPath(pathname: fileDescriptor.name)
             let filename = pathParts.base + pathParts.suffix
-            p.print(
+            fp.main.print(
                 "",
                 "// MARK: - Extension support defined in \(filename)."
             )
 
             // Generate the Swift Extensions on the Messages that provide the api
             // for using the protobuf extension.
-            extensionSet.generateMessageSwiftExtensions(printer: &p)
+            extensionSet.generateMessageSwiftExtensions(printer: &fp.main)
 
             // Generate a registry for the file.
-            extensionSet.generateFileProtobufExtensionRegistry(printer: &p)
+            extensionSet.generateFileProtobufExtensionRegistry(printer: &fp.main)
 
             // Generate the Extension's declarations (used by the two above things).
             //
             // This is done after the other two as the only time developers will need
             // these symbols is if they are manually building their own ExtensionMap;
             // so the others are assumed more interesting.
-            extensionSet.generateProtobufExtensionDeclarations(printer: &p)
+            extensionSet.generateProtobufExtensionDeclarations(printer: &fp.main)
         }
 
         let protoPackage = fileDescriptor.package
         let needsProtoPackage: Bool = !protoPackage.isEmpty && !messages.isEmpty
         if needsProtoPackage || !enums.isEmpty || !messages.isEmpty {
-            p.print(
-                "",
-                "// MARK: - Code below here is support for the SwiftProtobuf runtime."
-            )
-            if needsProtoPackage {
+            fp.forEachRuntimeExtension { p in
                 p.print(
                     "",
-                    "fileprivate let _protobuf_package = \"\(protoPackage)\""
+                    "// MARK: - Code below here is support for the SwiftProtobuf runtime."
                 )
+                if needsProtoPackage {
+                    p.print(
+                        "",
+                        "fileprivate let _protobuf_package = \"\(protoPackage)\""
+                    )
+                }
             }
             for e in enums {
-                e.generateRuntimeSupport(printer: &p)
+                e.generateRuntimeSupport(filePrinter: &fp)
             }
             for m in messages {
-                m.generateRuntimeSupport(printer: &p, file: self, parent: nil)
+                m.generateRuntimeSupport(filePrinter: &fp, file: self, parent: nil)
             }
         }
     }

Sources/protoc-gen-swift/FilePrinter.swift

@@ -0,0 +1,27 @@
+// Sources/protoc-gen-swift/MessageStorageDecision.swift
+//
+// Copyright (c) 2014 - 2016 Apple Inc. and the project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See LICENSE.txt for license information:
+// https://github.com/apple/swift-protobuf/blob/main/LICENSE.txt
+//
+// -----------------------------------------------------------------------------
+
+import SwiftProtobufPluginLibrary
+
+struct FilePrinter {
+    var main: CodePrinter
+    var hashable: CodePrinter
+    var nameProviding: CodePrinter
+
+    mutating func forEach(_ body: (_ p: inout CodePrinter) -> Void) {
+        body(&main)
+        forEachRuntimeExtension(body)
+    }
+
+    mutating func forEachRuntimeExtension(_ body: (_ p: inout CodePrinter) -> Void) {
+        body(&hashable)
+        body(&nameProviding)
+    }
+}

Sources/protoc-gen-swift/MessageGenerator.swift

@@ -205,12 +205,12 @@ class MessageGenerator {
         p.print("}")
     }
 
-    func generateRuntimeSupport(printer p: inout CodePrinter, file: FileGenerator, parent: MessageGenerator?) {
-        p.print(
+    func generateRuntimeSupport(filePrinter fp: inout FilePrinter, file: FileGenerator, parent: MessageGenerator?) {
+        fp.main.print(
             "",
-            "extension \(swiftFullName): \(namer.swiftProtobufModulePrefix)Message, \(namer.swiftProtobufModulePrefix)_MessageImplementationBase, \(namer.swiftProtobufModulePrefix)_ProtoNameProviding {"
+            "extension \(swiftFullName): \(namer.swiftProtobufModulePrefix)Message {"
         )
-        p.withIndentation { p in
+        fp.main.withIndentation { p in
             if let parent = parent {
                 p.print(
                     "\(visibility)static let protoMessageName: String = \(parent.swiftFullName).protoMessageName + \".\(descriptor.name)\""
@@ -222,7 +222,6 @@ class MessageGenerator {
             } else {
                 p.print("\(visibility)static let protoMessageName: String = \"\(descriptor.name)\"")
             }
-            generateProtoNameProviding(printer: &p)
             if let storage = storage {
                 p.print()
                 storage.generateTypeDeclaration(printer: &p)
@@ -235,17 +234,33 @@ class MessageGenerator {
             generateDecodeMessage(printer: &p)
             p.print()
             generateTraverse(printer: &p)
-            p.print()
+        }
+        fp.main.print("}")
+
+        fp.hashable.print(
+            "",
+            "extension \(swiftFullName): \(namer.swiftProtobufModulePrefix)_MessageImplementationBase {"
+        )
+        fp.hashable.withIndentation { p in
             generateMessageEquality(printer: &p)
         }
-        p.print("}")
+        fp.hashable.print("}")
+
+        fp.nameProviding.print(
+            "",
+            "extension \(swiftFullName): \(namer.swiftProtobufModulePrefix)_ProtoNameProviding {"
+        )
+        fp.nameProviding.withIndentation { p in
+            generateProtoNameProviding(printer: &p)
+        }
+        fp.nameProviding.print("}")
 
         // Nested enums and messages
         for e in enums {
-            e.generateRuntimeSupport(printer: &p)
+            e.generateRuntimeSupport(filePrinter: &fp)
         }
         for m in messages {
-            m.generateRuntimeSupport(printer: &p, file: file, parent: self)
+            m.generateRuntimeSupport(filePrinter: &fp, file: file, parent: self)
         }
     }
 

Sources/protoc-gen-swift/SwiftGeneratorPlugin.swift

@@ -35,14 +35,29 @@ struct SwiftGeneratorPlugin: CodeGenerator {
         var errorString: String? = nil
         for fileDescriptor in files {
             let fileGenerator = FileGenerator(fileDescriptor: fileDescriptor, generatorOptions: options)
-            var printer = CodePrinter(addNewlines: true)
-            fileGenerator.generateOutputFile(printer: &printer, errorString: &errorString)
+            var filePrinter = FilePrinter(
+                main: CodePrinter(addNewlines: true),
+                hashable: CodePrinter(addNewlines: true),
+                nameProviding: CodePrinter(addNewlines: true)
+            )
+            fileGenerator.generateOutputFile(filePrinter: &filePrinter, errorString: &errorString)
             if let errorString = errorString {
                 // If generating multiple files, scope the message with the file that triggered it.
                 let fullError = files.count > 1 ? "\(fileDescriptor.name): \(errorString)" : errorString
                 throw GenerationError.message(message: fullError)
             }
-            try generatorOutputs.add(fileName: fileGenerator.outputFilename, contents: printer.content)
+            try generatorOutputs.add(
+                fileName: fileGenerator.outputFilename(".pb.swift"),
+                contents: filePrinter.main.content
+            )
+            try generatorOutputs.add(
+                fileName: fileGenerator.outputFilename(".pb.hashable.swift"),
+                contents: filePrinter.hashable.content
+            )
+            try generatorOutputs.add(
+                fileName: fileGenerator.outputFilename(".pb.nameproviding.swift"),
+                contents: filePrinter.nameProviding.content
+            )
         }
     }