Swift2objC Public API (#1374)

pkgs/swift2objc/lib/src/config.dart

@@ -0,0 +1,108 @@
+import 'package:path/path.dart' as path;
+
+const defaultTempDirPrefix = 'swift2objc_temp_';
+const symbolgraphFileSuffix = '.symbols.json';
+
+class Command {
+  final String executable;
+  final List<String> args;
+
+  Command({
+    required this.executable,
+    required this.args,
+  });
+}
+
+/// Used to configure Swift2ObjC wrapper generation.
+class Config {
+  /// The input to generate a wrapper for.
+  /// See `FilesInputConfig` and `ModuleInputConfig`;
+  final InputConfig input;
+
+  /// Specify where the wrapper swift file will be output.
+  final Uri outputFile;
+
+  /// Specify where to output the intermidiate files (i.g the symbolgraph json).
+  /// If this is null, a teemp directory will be generated in the system temp
+  /// directory (using `Directory.systemTemp`) and then deleted.
+  /// Specifying a temp directory would prevent the tool from deleting the
+  /// intermediate files after generating the wrapper
+  final Uri? tempDir;
+
+  const Config({
+    required this.input,
+    required this.outputFile,
+    this.tempDir,
+  });
+}
+
+/// Used to specify the inputs in the `config` object.
+/// See `FilesInputConfig` and `ModuleInputConfig` for concrete implementation;
+sealed class InputConfig {
+  Command get symbolgraphCommand;
+}
+
+/// Used to generate a objc wrapper for one or more swift files
+class FilesInputConfig implements InputConfig {
+  /// The swift file(s) to generate a wrapper for
+  final List<Uri> files;
+
+  /// The name of the module files generated by `swiftc in `tempDir`
+  final String generatedModuleName;
+
+  FilesInputConfig({
+    required this.files,
+    this.generatedModuleName = 'symbolgraph_module',
+  });
+
+  @override
+  Command get symbolgraphCommand => Command(
+        executable: 'swiftc',
+        args: [
+          ...files.map((uri) => path.absolute(uri.path)),
+          '-emit-module',
+          '-emit-symbol-graph',
+          '-emit-symbol-graph-dir',
+          '.',
+          '-module-name',
+          generatedModuleName
+        ],
+      );
+}
+
+/// Used to generate a objc wrapper for a built-in swift module
+/// (e.g, AVFoundation)
+class ModuleInputConfig implements InputConfig {
+  /// The swift module to generate a wrapper for
+  final String module;
+
+  /// The target to generate code for
+  /// (e.g `x86_64-apple-ios17.0-simulator`)
+  final String target;
+
+  /// The sdk to compile against
+  /// (e.g `/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator.sd`)
+  final Uri sdk;
+
+  ModuleInputConfig({
+    required this.module,
+    required this.target,
+    required this.sdk,
+  });
+
+  @override
+  Command get symbolgraphCommand => Command(
+        executable: 'swiftc',
+        args: [
+          'symbolgraph-extract',
+          '-module-name',
+          module,
+          '-target',
+          target,
+          '-sdk',
+          path.absolute(sdk.path),
+          '-output-dir',
+          '.',
+        ],
+      );
+}

pkgs/swift2objc/lib/src/generate_wrapper.dart

@@ -0,0 +1,64 @@
+import 'dart:io';
+
+import 'package:path/path.dart' as path;
+
+import 'config.dart';
+import 'generator/generator.dart';
+import 'parser/parser.dart';
+import 'transformer/transform.dart';
+
+/// Used to generate the wrapper swift file.
+Future<void> generateWrapper(Config config) async {
+  final Directory tempDir;
+  final bool deleteTempDirWhenDone;
+
+  if (config.tempDir == null) {
+    tempDir = Directory.systemTemp.createTempSync(defaultTempDirPrefix);
+    deleteTempDirWhenDone = true;
+  } else {
+    tempDir = Directory.fromUri(config.tempDir!);
+    deleteTempDirWhenDone = false;
+  }
+
+  final input = config.input;
+
+  await _generateSymbolgraphJson(
+    input.symbolgraphCommand,
+    tempDir,
+  );
+
+  final symbolgraphFileName = switch (input) {
+    FilesInputConfig() => '${input.generatedModuleName}$symbolgraphFileSuffix',
+    ModuleInputConfig() => '${input.module}$symbolgraphFileSuffix',
+  };
+  final symbolgraphJsonPath = path.join(tempDir.path, symbolgraphFileName);
+
+  final declarations = parseAst(symbolgraphJsonPath);
+  final transformedDeclarations = transform(declarations);
+  final wrapperCode = generate(transformedDeclarations);
+
+  File.fromUri(config.outputFile).writeAsStringSync(wrapperCode);
+
+  if (deleteTempDirWhenDone) {
+    tempDir.deleteSync(recursive: true);
+  }
+}
+
+Future<void> _generateSymbolgraphJson(
+  Command symbolgraphCommand,
+  Directory workingDirectory,
+) async {
+  final result = await Process.run(
+    symbolgraphCommand.executable,
+    symbolgraphCommand.args,
+    workingDirectory: workingDirectory.path,
+  );
+
+  if (result.exitCode != 0) {
+    throw ProcessException(
+      symbolgraphCommand.executable,
+      symbolgraphCommand.args,
+      'Error generating symbol graph \n${result.stdout} \n${result.stderr}',
+    );
+  }
+}

pkgs/swift2objc/lib/src/generator/generator.dart

@@ -6,7 +6,7 @@ String generate(List<Declaration> declarations) {
   return '${[
     'import Foundation',
     ...declarations.map(generateDeclaration),
-  ].join('\n\n')}\n';
+  ].nonNulls.join('\n\n')}\n';
 }
 
 String generateDeclaration(Declaration declaration) {

pkgs/swift2objc/lib/src/parser/parsers/parse_relations_map.dart

@@ -2,6 +2,8 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+import 'dart:developer';
+
 import '../_core/json.dart';
 import '../_core/parsed_symbolgraph.dart';
 import '../_core/utils.dart';
@@ -21,9 +23,8 @@ ParsedRelationsMap parseRelationsMap(Json symbolgraphJson) {
     final relationKind = _supportedRelationKindsMap[relationKindString];
 
     if (relationKind == null) {
-      throw UnimplementedError(
-        '''Relation of value "$relationKindString" at path ${relationJson["kind"].path} is not implemneted yet''',
-      );
+      log('Relation of kind $relationKindString is not supported. Skipping it');
+      continue;
     }
 
     final sourceId = relationJson['source'].get<String>();

pkgs/swift2objc/lib/swift2objc.dart

@@ -2,6 +2,5 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-export 'src/generator/generator.dart' show generate;
-export 'src/parser/parser.dart' show parseAst;
-export 'src/transformer/transform.dart' show transform;
+export 'src/config.dart' show Config, FilesInputConfig, ModuleInputConfig;
+export 'src/generate_wrapper.dart';

pkgs/swift2objc/test/integration/integration_test.dart

@@ -11,7 +11,6 @@ import 'package:test/test.dart';
 void main() {
   group('Integration tests', () {
     const inputSuffix = '_input.swift';
-    const symbolSuffix = '_input.symbols.json';
     const outputSuffix = '_output.swift';
 
     final thisDir = path.join(Directory.current.path, 'test/integration');
@@ -29,41 +28,21 @@ void main() {
       test(name, () async {
         final inputFile = path.join(thisDir, '$name$inputSuffix');
         final expectedOutputFile = path.join(thisDir, '$name$outputSuffix');
-        final symbolFile = path.join(tempDir, '$name$symbolSuffix');
         final actualOutputFile = path.join(tempDir, '$name$outputSuffix');
 
-        expect(await generateSymbolGraph(inputFile, tempDir), isTrue);
-        expect(File(symbolFile).existsSync(), isTrue);
-
-        final declarations = parseAst(symbolFile);
-        final transformedDeclarations = transform(declarations);
-        final actualOutput = generate(transformedDeclarations);
-        File(actualOutputFile).writeAsStringSync(actualOutput);
+        await generateWrapper(Config(
+          input: FilesInputConfig(
+            files: [Uri.file(inputFile)],
+          ),
+          outputFile: Uri.file(actualOutputFile),
+          tempDir: Directory(tempDir).uri,
+        ));
 
+        final actualOutput = await File(actualOutputFile).readAsString();
         final expectedOutput = File(expectedOutputFile).readAsStringSync();
+
         expect(actualOutput, expectedOutput);
       });
     }
   });
 }
-
-Future<bool> generateSymbolGraph(String swiftFile, String outputDir) async {
-  final result = await Process.run(
-    'swiftc',
-    [
-      swiftFile,
-      '-emit-module',
-      '-emit-symbol-graph',
-      '-emit-symbol-graph-dir',
-      '.',
-    ],
-    workingDirectory: outputDir,
-  );
-  if (result.exitCode != 0) {
-    print('Error generating symbol graph');
-    print(result.stdout);
-    print(result.stderr);
-    return false;
-  }
-  return true;
-}