[vm] Rename --null-safety option to --sound-null-safety

Deprecated option --null-safety still remains in order to allow
graceful migration.

Fixes #41853

Change-Id: Ie47b1bebc9dd6532658a60743ecb85dc7fdc108c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/153660
Reviewed-by: Siva Annamalai <[email protected]>
Reviewed-by: Régis Crelier <[email protected]>
Commit-Queue: Alexander Markov <[email protected]>

Author: alexmarkov

pkg/front_end/test/fasta/testing/suite.dart

@@ -574,7 +574,7 @@ class Run extends Step<ComponentResult, int, FastaContext> {
           if (experimentalFlags[ExperimentalFlag.nonNullable]) {
             args.add("--enable-experiment=non-nullable");
             if (!context.weak) {
-              args.add("--null-safety");
+              args.add("--sound-null-safety");
             }
           }
           args.add(generated.path);

pkg/frontend_server/lib/frontend_server.dart

@@ -154,9 +154,12 @@ ArgParser argParser = ArgParser(allowTrailingOptions: true)
       help: 'Include only bytecode into the output file', defaultsTo: true)
   ..addFlag('enable-asserts',
       help: 'Whether asserts will be enabled.', defaultsTo: false)
+  ..addFlag('sound-null-safety',
+      help: 'Respect the nullability of types at runtime.', defaultsTo: null)
+  // TODO(alexmarkov) Remove obsolete --null-safety option.
   ..addFlag('null-safety',
-      help:
-          'Respect the nullability of types at runtime in casts and instance checks.',
+      help: 'Deprecated. Please use --sound-null-safety instead.',
+      hide: true,
       defaultsTo: null)
   ..addMultiOption('enable-experiment',
       help: 'Comma separated list of experimental features, eg set-literals.',
@@ -407,6 +410,8 @@ class FrontendCompiler implements CompilerInterface {
     final String platformKernelDill =
         options['platform'] ?? 'platform_strong.dill';
     final String packagesOption = _options['packages'];
+    final bool nullSafety =
+        _options['sound-null-safety'] ?? _options['null-safety'];
     final CompilerOptions compilerOptions = CompilerOptions()
       ..sdkRoot = sdkRoot
       ..fileSystem = _fileSystem
@@ -418,8 +423,7 @@ class FrontendCompiler implements CompilerInterface {
       ..experimentalFlags = parseExperimentalFlags(
           parseExperimentalArguments(options['enable-experiment']),
           onError: (msg) => errors.add(msg))
-      ..nnbdMode =
-          (options['null-safety'] == true) ? NnbdMode.Strong : NnbdMode.Weak
+      ..nnbdMode = (nullSafety == true) ? NnbdMode.Strong : NnbdMode.Weak
       ..onDiagnostic = _onDiagnostic;
 
     if (options.wasParsed('libraries-spec')) {
@@ -469,7 +473,7 @@ class FrontendCompiler implements CompilerInterface {
       }
     }
 
-    if (options['null-safety'] == null &&
+    if (nullSafety == null &&
         compilerOptions.experimentalFlags[ExperimentalFlag.nonNullable]) {
       await autoDetectNullSafetyMode(_mainSource, compilerOptions);
     }

pkg/vm/bin/kernel_service.dart

@@ -84,10 +84,10 @@ bool allowDartInternalImport = false;
 // Null Safety command line options
 //
 // Note: The values of these constants must match the
-// values of flag null_safety in ../../../../runtime/vm/flag_list.h.
-// 0 - No null_safety option specified on the command line.
-// 1 - '--no-null-safety' specified on the command line.
-// 2 - '--null-safety' option specified on the command line.
+// values of flag sound_null_safety in ../../../../runtime/vm/flag_list.h.
+// 0 - No --[no-]sound-null-safety option specified on the command line.
+// 1 - '--no-sound-null-safety' specified on the command line.
+// 2 - '--sound-null-safety' option specified on the command line.
 const int kNullSafetyOptionUnspecified = 0;
 const int kNullSafetyOptionWeak = 1;
 const int kNullSafetyOptionStrong = 2;

pkg/vm/lib/kernel_front_end.dart

@@ -118,9 +118,12 @@ void declareCompilerOptions(ArgParser args) {
       help: 'The values for the environment constants (e.g. -Dkey=value).');
   args.addFlag('enable-asserts',
       help: 'Whether asserts will be enabled.', defaultsTo: false);
+  args.addFlag('sound-null-safety',
+      help: 'Respect the nullability of types at runtime.', defaultsTo: null);
+  // TODO(alexmarkov) Remove obsolete --null-safety option.
   args.addFlag('null-safety',
-      help:
-          'Respect the nullability of types at runtime in casts and instance checks.',
+      help: 'Deprecated. Please use --sound-null-safety instead.',
+      hide: true,
       defaultsTo: null);
   args.addFlag('split-output-by-packages',
       help:
@@ -189,7 +192,8 @@ Future<int> runCompiler(ArgResults options, String usage) async {
   final bool genBytecode = options['gen-bytecode'];
   final bool dropAST = options['drop-ast'];
   final bool enableAsserts = options['enable-asserts'];
-  final bool nullSafety = options['null-safety'];
+  final bool nullSafety =
+      options['sound-null-safety'] ?? options['null-safety'];
   final bool useProtobufTreeShaker = options['protobuf-tree-shaker'];
   final bool useProtobufTreeShakerV2 = options['protobuf-tree-shaker-v2'];
   final bool splitOutputByPackages = options['split-output-by-packages'];

pkg/vm/tool/precompiler2

@@ -26,8 +26,8 @@ for arg in "$@"; do
     PACKAGES="$arg"
     ;;
     --enable-asserts | \
-    --null-safety | \
-    --no-null-safety | \
+    --sound-null-safety | \
+    --no-sound-null-safety | \
     --enable-experiment=*)
     GEN_KERNEL_OPTIONS+=("$arg")
     OPTIONS+=("$arg")

runtime/bin/BUILD.gn

@@ -551,7 +551,7 @@ gen_snapshot_action("generate_snapshot_bin") {
   ]
   args = [
     "--enable-experiment=non-nullable",
-    "--null-safety",
+    "--sound-null-safety",
     "--deterministic",
     "--snapshot_kind=" + dart_core_snapshot_kind,
     "--vm_snapshot_data=" + rebase_path(vm_snapshot_data, root_build_dir),

runtime/tests/vm/dart/run_appended_aot_snapshot_test.dart

@@ -29,8 +29,8 @@ Future<void> main(List<String> args) async {
     final extraGenKernelOptions = Platform.executableArguments
         .where((arg) =>
             arg.startsWith('--enable-experiment=') ||
-            arg == '--null-safety' ||
-            arg == '--no-null-safety')
+            arg == '--sound-null-safety' ||
+            arg == '--no-sound-null-safety')
         .toList();
 
     {

runtime/tests/vm/dart/split_aot_kernel_generation_test.dart

@@ -20,8 +20,8 @@ Future<void> runSplitAOTKernelGenerationTest(Uri testScriptUri) async {
     final extraGenKernelOptions = Platform.executableArguments
         .where((arg) =>
             arg.startsWith('--enable-experiment=') ||
-            arg == '--null-safety' ||
-            arg == '--no-null-safety')
+            arg == '--sound-null-safety' ||
+            arg == '--no-sound-null-safety')
         .toList();
 
     await runGenKernel('BUILD INTERMEDIATE DILL FILE', [

runtime/tests/vm/dart/type_casts_with_null_safety_autodetection_test.dart

@@ -20,7 +20,7 @@ runTest(String script, String output, String temp) async {
   File.fromUri(Platform.script.resolve(script)).copySync(scriptInTemp);
 
   // Do not add Platform.executableArguments into arguments to avoid passing
-  // --null-safety / --no-null-safety arguments.
+  // --sound-null-safety / --no-sound-null-safety arguments.
   final result = await runBinary("RUN $script", Platform.executable, [
     '--enable-experiment=non-nullable',
     '--deterministic',

runtime/tests/vm/dart/v8_snapshot_profile_writer_test.dart

@@ -245,8 +245,8 @@ main() async {
       platformDill,
       ...Platform.executableArguments.where((arg) =>
           arg.startsWith('--enable-experiment=') ||
-          arg == '--null-safety' ||
-          arg == '--no-null-safety'),
+          arg == '--sound-null-safety' ||
+          arg == '--no-sound-null-safety'),
       '-o',
       dillPath,
       _thisTestPath