[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]>

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

runtime/tests/vm/dart_2/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/vm/benchmark_test.cc

@@ -359,7 +359,7 @@ static Dart_NativeFunction NativeResolver(Dart_Handle name,
 // Measure compile of all kernel Service(CFE) functions.
 //
 BENCHMARK(KernelServiceCompileAll) {
-  if (FLAG_null_safety == kNullSafetyOptionStrong) {
+  if (FLAG_sound_null_safety == kNullSafetyOptionStrong) {
     // TODO(bkonyi): remove this check when we build the CFE in strong mode.
     return;
   }

runtime/vm/clustered_snapshot.cc

@@ -6785,14 +6785,14 @@ char* SnapshotHeaderReader::InitializeGlobalVMFlagsFromSnapshot(
 #undef SET_FLAG
 
 #if defined(DART_PRECOMPILED_RUNTIME)
-    if (FLAG_null_safety == kNullSafetyOptionUnspecified) {
+    if (FLAG_sound_null_safety == kNullSafetyOptionUnspecified) {
       if (strncmp(cursor, "null-safety", end - cursor) == 0) {
-        FLAG_null_safety = kNullSafetyOptionStrong;
+        FLAG_sound_null_safety = kNullSafetyOptionStrong;
         cursor = end;
         continue;
       }
       if (strncmp(cursor, "no-null-safety", end - cursor) == 0) {
-        FLAG_null_safety = kNullSafetyOptionWeak;
+        FLAG_sound_null_safety = kNullSafetyOptionWeak;
         cursor = end;
         continue;
       }

runtime/vm/dart.cc

@@ -763,7 +763,7 @@ bool Dart::DetectNullSafety(const char* script_uri,
   //   generating the kernel file
   // - if loading from an appJIT, based on the mode used
   //   when generating the snapshot.
-  ASSERT(FLAG_null_safety == kNullSafetyOptionUnspecified);
+  ASSERT(FLAG_sound_null_safety == kNullSafetyOptionUnspecified);
 
   // If snapshot is an appJIT/AOT snapshot we will figure out the mode by
   // sniffing the feature string in the snapshot.
@@ -1025,7 +1025,7 @@ const char* Dart::FeaturesString(Isolate* isolate,
         buffer.AddString(" no-null-safety");
       }
     } else {
-      if (FLAG_null_safety == kNullSafetyOptionStrong) {
+      if (FLAG_sound_null_safety == kNullSafetyOptionStrong) {
         buffer.AddString(" null-safety");
       } else {
         buffer.AddString(" no-null-safety");

runtime/vm/dart_api_impl.cc

@@ -3051,7 +3051,7 @@ DART_EXPORT Dart_Handle Dart_NewListOf(Dart_CoreType_Id element_type_id,
   DARTSCOPE(Thread::Current());
   if (T->isolate()->null_safety() && element_type_id != Dart_CoreType_Dynamic) {
     return Api::NewError(
-        "Cannot use legacy types with --null-safety enabled. "
+        "Cannot use legacy types with --sound-null-safety enabled. "
         "Use Dart_NewListOfType or Dart_NewListOfTypeFilled instead.");
   }
   CHECK_LENGTH(length, Array::kMaxElements);
@@ -5599,7 +5599,7 @@ DART_EXPORT Dart_Handle Dart_GetType(Dart_Handle library,
                                      Dart_Handle* type_arguments) {
   if (Thread::Current()->isolate()->null_safety()) {
     return Api::NewError(
-        "Cannot use legacy types with --null-safety enabled. "
+        "Cannot use legacy types with --sound-null-safety enabled. "
         "Use Dart_GetNullableType or Dart_GetNonNullableType instead.");
   }
   return GetTypeCommon(library, class_name, number_of_type_arguments,
@@ -6033,16 +6033,16 @@ DART_EXPORT bool Dart_DetectNullSafety(const char* script_uri,
                                        const uint8_t* kernel_buffer,
                                        intptr_t kernel_buffer_size) {
 #if defined(DART_PRECOMPILED_RUNTIME)
-  ASSERT(FLAG_null_safety != kNullSafetyOptionUnspecified);
-  return (FLAG_null_safety == kNullSafetyOptionStrong);
+  ASSERT(FLAG_sound_null_safety != kNullSafetyOptionUnspecified);
+  return (FLAG_sound_null_safety == kNullSafetyOptionStrong);
 #else
   bool null_safety;
-  if (FLAG_null_safety == kNullSafetyOptionUnspecified) {
+  if (FLAG_sound_null_safety == kNullSafetyOptionUnspecified) {
     null_safety = Dart::DetectNullSafety(
         script_uri, snapshot_data, snapshot_instructions, kernel_buffer,
         kernel_buffer_size, package_config, original_working_directory);
   } else {
-    null_safety = (FLAG_null_safety == kNullSafetyOptionStrong);
+    null_safety = (FLAG_sound_null_safety == kNullSafetyOptionStrong);
   }
   return null_safety;
 #endif  // defined(DART_PRECOMPILED_RUNTIME)

runtime/vm/dart_api_impl_test.cc

@@ -5335,7 +5335,7 @@ TEST_CASE(DartAPI_NewListOf) {
     EXPECT_STREQ("null", str);
   } else {
     EXPECT_ERROR(string_list,
-                 "Cannot use legacy types with --null-safety enabled. "
+                 "Cannot use legacy types with --sound-null-safety enabled. "
                  "Use Dart_NewListOfType or Dart_NewListOfTypeFilled instead.");
   }
 
@@ -5356,7 +5356,7 @@ TEST_CASE(DartAPI_NewListOf) {
     EXPECT_STREQ("null", str);
   } else {
     EXPECT_ERROR(int_list,
-                 "Cannot use legacy types with --null-safety enabled. "
+                 "Cannot use legacy types with --sound-null-safety enabled. "
                  "Use Dart_NewListOfType or Dart_NewListOfTypeFilled instead.");
   }
 }
@@ -6222,7 +6222,7 @@ TEST_CASE(DartAPI_TypeToNullability) {
   if (Dart_IsError(type)) {
     EXPECT_ERROR(
         type,
-        "Cannot use legacy types with --null-safety enabled. "
+        "Cannot use legacy types with --sound-null-safety enabled. "
         "Use Dart_GetNullableType or Dart_GetNonNullableType instead.");
 
     nonNullableType = Dart_GetNonNullableType(lib, name, 0, nullptr);

runtime/vm/isolate.cc

@@ -88,15 +88,20 @@ DEFINE_FLAG_HANDLER(DeterministicModeHandler,
                     deterministic,
                     "Enable deterministic mode.");
 
-int FLAG_null_safety = kNullSafetyOptionUnspecified;
-static void NullSafetyHandler(bool value) {
-  FLAG_null_safety = value ? kNullSafetyOptionStrong : kNullSafetyOptionWeak;
+int FLAG_sound_null_safety = kNullSafetyOptionUnspecified;
+static void SoundNullSafetyHandler(bool value) {
+  FLAG_sound_null_safety =
+      value ? kNullSafetyOptionStrong : kNullSafetyOptionWeak;
 }
 
-DEFINE_FLAG_HANDLER(
-    NullSafetyHandler,
-    null_safety,
-    "Respect the nullability of types in casts and instance checks.");
+DEFINE_FLAG_HANDLER(SoundNullSafetyHandler,
+                    sound_null_safety,
+                    "Respect the nullability of types at runtime.");
+
+// TODO(alexmarkov) Remove obsolete --null-safety option.
+DEFINE_FLAG_HANDLER(SoundNullSafetyHandler,
+                    null_safety,
+                    "Respect the nullability of types at runtime.");
 
 DEFINE_FLAG(bool,
             disable_thread_pool_limit,

runtime/vm/isolate.h

@@ -99,7 +99,7 @@ class WeakTable;
 constexpr int kNullSafetyOptionUnspecified = 0;
 constexpr int kNullSafetyOptionWeak = 1;
 constexpr int kNullSafetyOptionStrong = 2;
-extern int FLAG_null_safety;
+extern int FLAG_sound_null_safety;
 
 class PendingLazyDeopt {
  public:

runtime/vm/kernel_isolate.cc

@@ -777,7 +777,7 @@ class KernelCompilationRequest : public ValueObject {
     null_safety.value.as_int32 =
         (isolate != NULL) ? (isolate->null_safety() ? kNullSafetyOptionStrong
                                                     : kNullSafetyOptionWeak)
-                          : FLAG_null_safety;
+                          : FLAG_sound_null_safety;
 
     intptr_t num_experimental_flags = experimental_flags->length();
     Dart_CObject** experimental_flags_array =

runtime/vm/kernel_loader.cc

@@ -1045,15 +1045,17 @@ LibraryPtr KernelLoader::LoadLibrary(intptr_t index) {
       library_helper.GetNonNullableByDefaultCompiledMode();
   if (!I->null_safety() && mode == NNBDCompiledMode::kStrong) {
     H.ReportError(
-        "Library '%s' was compiled with null safety (in strong mode) and it "
-        "requires --null-safety option at runtime",
+        "Library '%s' was compiled with sound null safety (in strong mode) and "
+        "it "
+        "requires --sound-null-safety option at runtime",
         String::Handle(library.url()).ToCString());
   }
   if (I->null_safety() && (mode == NNBDCompiledMode::kWeak ||
                            mode == NNBDCompiledMode::kDisabled)) {
     H.ReportError(
-        "Library '%s' was compiled without null safety (in weak mode) and it "
-        "cannot be used with --null-safety at runtime",
+        "Library '%s' was compiled without sound null safety (in weak mode) "
+        "and it "
+        "cannot be used with --sound-null-safety at runtime",
         String::Handle(library.url()).ToCString());
   }
   library.set_nnbd_compiled_mode(mode);

runtime/vm/object.h

@@ -908,8 +908,7 @@ enum class TypeEquality {
 };
 
 // The NNBDMode reflects the opted-in status of libraries.
-// Note that the weak or strong testing mode is not reflected in NNBDMode, but
-// imposed globally by the value of --null-safety.
+// Note that the weak or strong checking mode is not reflected in NNBDMode.
 enum class NNBDMode {
   // Status of the library:
   kLegacyLib = 0,   // Library is legacy.

tests/corelib/list_removeat_test.dart

@@ -26,8 +26,8 @@ void testModifiableList(l1) {
   Expect.throwsRangeError(() => l1.removeAt(-1), "negative");
   Expect.throwsRangeError(() => l1.removeAt(5), "too large");
   Expect.throws(() => l1.removeAt(null),
-      // With --null-safety a TypeError is thrown
-      // With --no-null-safety an ArgumentError is thrown
+      // With sound null safety a TypeError is thrown.
+      // Without sound null safety an ArgumentError is thrown.
       (e) => e is TypeError || e is ArgumentError, "is null");
 
   Expect.equals(2, l1.removeAt(2), "l1-remove2");