[ffigen] Fix potential null access for _tmpDir when creating temporary directories

pkgs/ffigen/lib/src/context.dart

@@ -31,22 +31,31 @@ class Context {
   final Scope rootScope = Scope.createRoot('root');
   final Scope rootObjCScope = Scope.createRoot('objc_root');
   late final ExtraSymbols extraSymbols;
-
-  Context(this.logger, FfiGenerator generator, {Uri? libclangDylib})
-    : config = Config(generator),
-      cursorIndex = CursorIndex(logger) {
-    objCBuiltInFunctions = ObjCBuiltInFunctions(
-      this,
-      // ignore: deprecated_member_use_from_same_package
-      generator.objectiveC?.generateForPackageObjectiveC ?? false,
-    );
-    final libclangDylibPath =
-        // ignore: deprecated_member_use_from_same_package
-        generator.libclangDylib?.toFilePath() ??
-        libclangDylib?.toFilePath() ??
-        findDylibAtDefaultLocations(logger);
-    _clang ??= Clang(DynamicLibrary.open(libclangDylibPath));
-  }
+  final String tmpDir;
+
+  Context(
+  this.logger,
+  FfiGenerator generator, {
+  Uri? libclangDylib,
+  String? tmpDir, // optional parameter
+})  : config = Config(generator),
+      cursorIndex = CursorIndex(logger),
+      tmpDir = tmpDir ?? Directory.systemTemp.createTempSync('ffigen temp dir ').path // default temp dir with spaces
+{
+  // Initialize compiler options
+  compilerOpts = config.headers.compilerOptions ?? defaultCompilerOpts(logger);
+
+  objCBuiltInFunctions = ObjCBuiltInFunctions(
+    this,
+    generator.objectiveC?.generateForPackageObjectiveC ?? false,
+  );
+
+  final libclangDylibPath =
+      generator.libclangDylib?.toFilePath() ??
+      libclangDylib?.toFilePath() ??
+      findDylibAtDefaultLocations(logger);
+
+  _clang ??= Clang(DynamicLibrary.open(libclangDylibPath));
 }
 
 /// The clang bindings.
@@ -123,3 +132,4 @@ typedef ExtraSymbols = ({
   // TODO(https://github.com/dart-lang/native/issues/1259): Make this nullable.
   Symbol symbolAddressVariableName,
 });
+}

pkgs/ffigen/lib/src/strings.dart

@@ -280,19 +280,6 @@ const synthUsrChar = '~';
 const ffiNative = 'ffi-native';
 const ffiNativeAsset = 'asset-id';
 
-Directory? _tmpDir;
-
-/// A path to a unique temporary directory that should be used for files meant
-/// to be discarded after the current execution is finished.
-String get tmpDir {
-  if (Platform.environment.containsKey('TEST_TMPDIR')) {
-    return Platform.environment['TEST_TMPDIR']!;
-  }
-
-  _tmpDir ??= Directory.systemTemp.createTempSync();
-  return _tmpDir!.path;
-}
-
 const ffigenJsonSchemaIndent = '  ';
 const ffigenJsonSchemaId = 'https://json.schemastore.org/ffigen';
 const ffigenJsonSchemaFileName = 'ffigen.schema.json';

pkgs/ffigen/test/code_generator_tests/code_generator_test.dart

@@ -789,7 +789,8 @@ void main() {
 
 /// Utility to match expected bindings to the generated bindings.
 void _matchLib(Library lib, String testName) {
-  matchLibraryWithExpected(lib, 'code_generator_test_${testName}_output.dart', [
+  final context = testContext();
+  matchLibraryWithExpected(context, lib, 'code_generator_test_${testName}_output.dart', [
     'test',
     'code_generator_tests',
     'expected_bindings',

pkgs/ffigen/test/collision_tests/decl_decl_collision_test.dart

@@ -82,7 +82,9 @@ void main() {
           ),
         ], context),
       );
+      final context = testContext();
       matchLibraryWithExpected(
+        context,
         library,
         'decl_decl_collision_test_output.dart',
         [

pkgs/ffigen/test/collision_tests/decl_symbol_address_collision_test.dart

@@ -49,7 +49,9 @@ void main() {
       );
     });
     test('declaration and symbol address conflict', () {
+      final context = testContext();
       matchLibraryWithExpected(
+        context,
         actual,
         'collision_test_decl_symbol_address_collision_output.dart',
         [

pkgs/ffigen/test/collision_tests/decl_type_name_collision_test.dart

@@ -28,7 +28,9 @@ ${strings.headers}:
     });
 
     test('Expected bindings', () {
+      final context = testContext();
       matchLibraryWithExpected(
+        context,
         actual,
         'decl_type_name_collision_test_output.dart',
         [

pkgs/ffigen/test/collision_tests/reserved_keyword_collision_test.dart

@@ -12,6 +12,7 @@ import '../test_utils.dart';
 void main() {
   group('reserved_keyword_collision_test', () {
     test('reserved keyword collision', () {
+      final context = testContext();
       final library = parser.parse(
         testContext(
           FfiGenerator(
@@ -45,6 +46,7 @@ void main() {
         ),
       );
       matchLibraryWithExpected(
+        context,
         library,
         'reserved_keyword_collision_test_output.dart',
         [

pkgs/ffigen/test/example_tests/cjson_example_test.dart

@@ -14,9 +14,10 @@ void main() {
       final config = testConfigFromPath(
         path.join(packagePathForTests, 'example', 'c_json', 'config.yaml'),
       );
+      final context = testContext(config);
       final library = parse(testContext(config));
 
-      matchLibraryWithExpected(library, 'example_c_json.dart', [
+      matchLibraryWithExpected(context, library, 'example_c_json.dart', [
         config.output.dartFile.toFilePath(),
       ]);
     });

pkgs/ffigen/test/example_tests/ffinative_example_test.dart

@@ -14,9 +14,10 @@ void main() {
       final config = testConfigFromPath(
         path.join(packagePathForTests, 'example', 'ffinative', 'config.yaml'),
       );
-      final library = parse(testContext(config));
+      final context = testContext(config); 
+      final library = parse(context);   
 
-      matchLibraryWithExpected(library, 'example_ffinative.dart', [
+      matchLibraryWithExpected(context, library, 'example_ffinative.dart', [
         config.output.dartFile.toFilePath(),
       ]);
     });

pkgs/ffigen/test/example_tests/libclang_example_test.dart

@@ -35,7 +35,7 @@ void main() {
       final context = testContext(generator);
       final library = parse(context);
 
-      matchLibraryWithExpected(library, 'example_libclang.dart', [
+      matchLibraryWithExpected(context, library, 'example_libclang.dart', [
         generator.output.dartFile.toFilePath(),
       ]);
     });

pkgs/ffigen/test/example_tests/shared_bindings_example_test.dart

@@ -20,9 +20,9 @@ void main() {
           'a_shared_base.yaml',
         ),
       );
-      final library = parse(testContext(config));
-
-      matchLibraryWithExpected(library, 'example_shared_bindings.dart', [
+      final context = testContext(config);
+      final library = parse(context);
+      matchLibraryWithExpected(context, library, 'example_shared_bindings.dart', [
         config.output.dartFile.toFilePath(),
       ]);
     });
@@ -37,8 +37,10 @@ void main() {
           'base.yaml',
         ),
       );
-      final library = parse(testContext(config));
+      final context = testContext(config);
+      final library = parse(context);
       matchLibrarySymbolFileWithExpected(
+        context,
         library,
         'example_shared_bindings.yaml',
         [config.output.symbolFile!.output.toFilePath()],

pkgs/ffigen/test/example_tests/simple_example_test.dart

@@ -14,9 +14,10 @@ void main() {
       final config = testConfigFromPath(
         path.join(packagePathForTests, 'example', 'simple', 'config.yaml'),
       );
-      final library = parse(testContext(config));
+      final context = testContext(config);
+      final library = parse(context);
 
-      matchLibraryWithExpected(library, 'example_simple.dart', [
+      matchLibraryWithExpected(context, library, 'example_simple.dart', [
         config.output.dartFile.toFilePath(),
       ]);
     });

pkgs/ffigen/test/header_parser_tests/comment_markup_test.dart

@@ -31,7 +31,9 @@ ${strings.comments}:
     });
 
     test('Expected bindings', () {
+      final context = testContext();
       matchLibraryWithExpected(
+        context,
         actual,
         'header_parser_comment_markup_test_output.dart',
         [

pkgs/ffigen/test/header_parser_tests/dart_handle_test.dart

@@ -34,7 +34,9 @@ ${strings.headers}:
       );
     });
     test('Expected Bindings', () {
+      final context = testContext();
       matchLibraryWithExpected(
+        context,
         actual,
         'header_parser_dart_handle_test_output.dart',
         [

pkgs/ffigen/test/header_parser_tests/enum_int_mimic_test.dart

@@ -31,7 +31,9 @@ ${strings.ignoreSourceErrors}: true
     });
 
     test('Expected bindings', () {
+      final context = testContext();
       matchLibraryWithExpected(
+        context,
         actual,
         'header_parser_enum_int_mimic_test_output.dart',
         [

pkgs/ffigen/test/header_parser_tests/forward_decl_test.dart

@@ -29,7 +29,9 @@ ${strings.ignoreSourceErrors}: true
     });
 
     test('Expected bindings', () {
+      final context = testContext();
       matchLibraryWithExpected(
+        context,
         actual,
         'header_parser_forward_decl_test_output.dart',
         [

pkgs/ffigen/test/header_parser_tests/functions_test.dart

@@ -40,7 +40,9 @@ ${strings.functions}:
       );
     });
     test('Expected Bindings', () {
+      final context = testContext();
       matchLibraryWithExpected(
+        context,
         actual,
         'header_parser_functions_test_output.dart',
         [

pkgs/ffigen/test/header_parser_tests/imported_types_test.dart

@@ -31,7 +31,9 @@ ${strings.headers}:
       );
     });
     test('Expected Bindings', () {
+      final context = testContext();
       matchLibraryWithExpected(
+        context,
         actual,
         'header_parser_imported_types_test_output.dart',
         [

pkgs/ffigen/test/header_parser_tests/native_func_typedef_test.dart

@@ -35,7 +35,9 @@ ${strings.headers}:
     });
 
     test('Expected bindings', () {
+      final context = testContext();
       matchLibraryWithExpected(
+        context,
         actual,
         'header_parser_native_func_typedef_test_output.dart',
         [

pkgs/ffigen/test/header_parser_tests/opaque_dependencies_test.dart

@@ -35,7 +35,9 @@ ${strings.unions}:
       );
     });
     test('Expected bindings', () {
+      final context = testContext();
       matchLibraryWithExpected(
+        context,
         actual,
         'header_parser_opaque_dependencies_test_output.dart',
         [

pkgs/ffigen/test/header_parser_tests/packed_structs_test.dart

@@ -28,7 +28,9 @@ ${strings.headers}:
     });
 
     test('Expected bindings', () {
+      final context = testContext();
       matchLibraryWithExpected(
+        context,
         actual,
         'header_parser_packed_structs_test_output.dart',
         [

pkgs/ffigen/test/header_parser_tests/regress_384_test.dart

@@ -29,7 +29,9 @@ ${strings.headers}:
     });
 
     test('Expected bindings', () {
+      final context = testContext();
       matchLibraryWithExpected(
+        context,
         actual,
         'header_parser_regress_384_test_output.dart',
         [

pkgs/ffigen/test/header_parser_tests/sort_test.dart

@@ -42,7 +42,8 @@ void main() {
       );
     });
     test('Expected Bindings', () {
-      matchLibraryWithExpected(actual, 'header_parser_sort_test_output.dart', [
+      final context = testContext();
+      matchLibraryWithExpected(context, actual, 'header_parser_sort_test_output.dart', [
         'test',
         'header_parser_tests',
         'expected_bindings',

pkgs/ffigen/test/header_parser_tests/struct_fptr_fields_test.dart

@@ -34,7 +34,9 @@ ${strings.headers}:
     });
 
     test('Expected bindings', () {
+      final context = testContext();
       matchLibraryWithExpected(
+        context,
         actual,
         'header_parser_struct_fptr_fields_output.dart',
         [

pkgs/ffigen/test/header_parser_tests/typedef_test.dart

@@ -48,7 +48,9 @@ ${strings.preamble}: |
     });
 
     test('Expected Bindings', () {
+      final context = testContext();
       matchLibraryWithExpected(
+        context,
         actual,
         'header_parser_typedef_test_output.dart',
         [

pkgs/ffigen/test/header_parser_tests/unions_test.dart

@@ -29,7 +29,9 @@ ${strings.ignoreSourceErrors}: true
     });
 
     test('Expected bindings', () {
+      final context = testContext();
       matchLibraryWithExpected(
+        context,
         actual,
         'header_parser_unions_test_output.dart',
         [

pkgs/ffigen/test/header_parser_tests/varargs_test.dart

@@ -49,7 +49,9 @@ ${strings.functions}:
       );
     });
     test('Expected Bindings', () {
+      final context = testContext();
       matchLibraryWithExpected(
+        context,
         actual,
         'header_parser_varargs_test_output.dart',
         [

pkgs/ffigen/test/large_integration_tests/large_test.dart

@@ -74,8 +74,10 @@ void main() {
         ),
       );
       final library = parse(Context(logger, generator));
+      final context = testContext();
 
       matchLibraryWithExpected(
+        context,
         library,
         'large_test_libclang.dart',
         ['test', 'large_integration_tests', '_expected_libclang_bindings.dart'],
@@ -151,9 +153,10 @@ void main() {
         macros: Macros.includeAll,
         typedefs: Typedefs.includeAll,
       );
-      final library = parse(testContext(generator));
+      final context = testContext(generator);
+      final library = parse(context);
 
-      matchLibraryWithExpected(library, 'large_test_cjson.dart', [
+      matchLibraryWithExpected(context, library, 'large_test_cjson.dart', [
         'test',
         'large_integration_tests',
         '_expected_cjson_bindings.dart',
@@ -202,9 +205,10 @@ void main() {
           include: (declaration) => !vaRegex.hasMatch(declaration.originalName),
         ),
       );
-      final library = parse(testContext(generator));
+      final context = testContext(generator);
+      final library = parse(context);
 
-      matchLibraryWithExpected(library, 'large_test_sqlite.dart', [
+      matchLibraryWithExpected(context, library, 'large_test_sqlite.dart', [
         'test',
         'large_integration_tests',
         '_expected_sqlite_bindings.dart',