[dart2js] Replace references to NNBD with null safety.

Change-Id: Id23dce928425c99770ced629f866cee01fa2ef0c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/212240
Reviewed-by: Joshua Litt <joshualitt@google.com>
Commit-Queue: Mayank Patke <fishythefish@google.com>

pkg/compiler/lib/src/elements/types.dart

@@ -1707,7 +1707,7 @@ abstract class DartTypes {
 
   DartType nullableType(DartType baseType) {
     bool _isNullable(DartType t) =>
-        // Note that we can assume NNBD is enabled here.
+        // Note that we can assume null safety is enabled here.
         t.isNull ||
         t is NullableType ||
         t is LegacyType && _isNullable(t.baseType) ||

pkg/compiler/lib/src/js_backend/specialized_checks.dart

@@ -72,8 +72,8 @@ class SpecializedChecks {
       }
 
       DartTypes dartTypes = closedWorld.dartTypes;
-      // Top types (here it could be Object in non-NNBD mode) should be constant
-      // folded outside the specializer. This test protects logic below.
+      // Top types should be constant folded outside the specializer. This test
+      // protects logic below.
       if (dartTypes.isTopType(dartType)) return null;
       ElementEnvironment elementEnvironment = closedWorld.elementEnvironment;
       if (!dartTypes.isSubtype(

pkg/compiler/lib/src/kernel/loader.dart

@@ -61,7 +61,8 @@ class KernelLoaderTask extends CompilerTask {
       String targetName =
           _options.compileForServer ? "dart2js_server" : "dart2js";
 
-      // We defer selecting the platform until we've resolved the NNBD mode.
+      // We defer selecting the platform until we've resolved the null safety
+      // mode.
       String getPlatformFilename() {
         String platform = targetName;
         if (!_options.useLegacySubtyping) {

pkg/compiler/lib/src/native/behavior.dart

@@ -838,7 +838,7 @@ abstract class BehaviorBuilder {
     _behavior.typesReturned.add(type.withoutNullability);
 
     // Breakdown nullable type into TypeWithoutNullability|Null.
-    // Pre-nnbd Declared types are nullable, so we also add null in that case.
+    // Unsound declared types are nullable, so we also add null in that case.
     // TODO(41960): Remove check for legacy subtyping. This was added as a
     // temporary workaround to unblock the null-safe unfork. At this time some
     // native APIs are typed unsoundly because they don't consider browser

pkg/compiler/lib/src/options.dart

@@ -708,7 +708,7 @@ class CompilerOptions implements DiagnosticOptions {
 
     if (benchmarkingExperiment) {
       // Set flags implied by '--benchmarking-x'.
-      // TODO(sra): Use this for some NNBD variant.
+      // TODO(sra): Use this for some null safety variant.
       useContentSecurityPolicy = true;
       features.forceCanary();
     }

pkg/compiler/lib/src/ssa/nodes.dart

@@ -3517,10 +3517,10 @@ class HLateValue extends HLateInstruction {
 /// Check for receiver or argument type when lowering operation to a primitive,
 /// e.g. lowering `+` to [HAdd].
 ///
-/// After NNBD, `a + b` will require `a` and `b` are non-nullable and these
-/// checks will become explicit in the source (e.g. `a! + b!`). At that time,
-/// this check should be removed.  If needed, the `!` check can be optimized
-/// give the same signals to the JavaScript VM.
+/// With sound null safety, `a + b` will require `a` and `b` to be non-nullable
+/// and these checks will become explicit in the source (e.g. `a! + b!`). At
+/// that time, this check should be removed. If needed, the `!` check can be
+/// optimized to give the same signals to the JavaScript VM.
 class HPrimitiveCheck extends HCheck {
   // Values for [kind].
   static const int ARGUMENT_TYPE_CHECK = 1;
@@ -3590,8 +3590,8 @@ class HPrimitiveCheck extends HCheck {
 }
 
 /// A check that the input to a condition (if, ?:, while, etc) is non-null. The
-/// front-end generates 'as bool' checks, but until the transition to NNBD is
-/// complete, this allows `null` to be passed to the condition.
+/// front-end generates 'as bool' checks, but until the transition to null
+/// safety is complete, this allows `null` to be passed to the condition.
 ///
 // TODO(sra): Once NNDB is far enough along that the front-end can generate `as
 // bool!` checks and the backend checks them correctly, this instruction will

pkg/compiler/lib/src/ssa/optimize.dart

@@ -1926,8 +1926,8 @@ class SsaInstructionSimplifier extends HBaseVisitor
   @override
   HInstruction visitAsCheck(HAsCheck node) {
     // TODO(fishythefish): Correctly constant fold `null as T` (also in
-    // [visitAsCheckSimple]) when running with strong NNBD. We might get this
-    // for free if nullability is precisely propagated to the typemasks.
+    // [visitAsCheckSimple]) when running with sound null safety. We might get
+    // this for free if nullability is precisely propagated to the typemasks.
 
     HInstruction typeInput = node.typeInput;
     if (typeInput is HLoadType) {

pkg/compiler/test/closure/data/test_type_class.dart

@@ -33,7 +33,7 @@ class Class2<T> {
 }
 
 ////////////////////////////////////////////////////////////////////////////////
-/// Implicit as-cast is only required in spec:nnbd-off mode.
+/// Implicit as-cast is only required in spec mode.
 ////////////////////////////////////////////////////////////////////////////////
 
 /*member: Class3.:hasThis*/

pkg/compiler/test/closure/data/test_type_method.dart

@@ -27,7 +27,7 @@ method2<T>(dynamic o) {
 }
 
 ////////////////////////////////////////////////////////////////////////////////
-/// Implicit as-cast is only required in spec:nnbd-off mode.
+/// Implicit as-cast is only required in spec mode.
 ////////////////////////////////////////////////////////////////////////////////
 
 /*member: method3:*/

pkg/compiler/test/closure/data/type_annotations_class.dart

@@ -43,7 +43,7 @@ class Class1b<T> {
 }
 
 ////////////////////////////////////////////////////////////////////////////////
-/// A local function parameter type is only captured in spec:nnbd-off mode.
+/// A local function parameter type is only captured in spec mode.
 ////////////////////////////////////////////////////////////////////////////////
 
 /*member: Class2.:hasThis*/
@@ -58,7 +58,7 @@ class Class2<T> {
 }
 
 ////////////////////////////////////////////////////////////////////////////////
-/// A local function return type is only captured in spec:nnbd-off mode.
+/// A local function return type is only captured in spec mode.
 ////////////////////////////////////////////////////////////////////////////////
 
 /*member: Class3.:hasThis*/

pkg/compiler/test/closure/data/type_annotations_method.dart

@@ -19,7 +19,7 @@ method1<T>(T o) {
 }
 
 ////////////////////////////////////////////////////////////////////////////////
-/// A local function parameter type is captured in spec:nnbd-off mode.
+/// A local function parameter type is captured in spec mode.
 ////////////////////////////////////////////////////////////////////////////////
 
 method2<T>() {
@@ -29,7 +29,7 @@ method2<T>() {
 }
 
 ////////////////////////////////////////////////////////////////////////////////
-/// A local function return type is captured in spec:nnbd-off mode.
+/// A local function return type is captured in spec mode.
 ////////////////////////////////////////////////////////////////////////////////
 
 method3<T>(dynamic o) {

pkg/compiler/test/codegen/new_rti_is_test.dart

@@ -11,7 +11,7 @@ import 'package:async_helper/async_helper.dart';
 import '../helpers/compiler_helper.dart';
 
 // 'N' tests all have a nullable input so should not reduce is-test.
-// TODO(NNBD): Add tests with non-nullable input types.
+// TODO(sra): Add tests with non-nullable input types.
 
 const TEST1N = r"""
 foo(int a) {

pkg/compiler/test/inference/data/list_tracer_typed_data_length.dart

@@ -6,8 +6,8 @@
 
 import 'dart:typed_data';
 
-// TODO(johnniwinther): Fix inference for spec:nnbd-off mode. List elements should not
-// be [empty].
+// TODO(johnniwinther): Fix inference for spec mode. List elements should not be
+// [empty].
 
 /*member: myList:Container([null|exact=NativeFloat32List], element: [subclass=JSNumber], length: 42)*/
 var myList = new Float32List(42);

pkg/compiler/test/kernel/goldens_test.dart

@@ -14,9 +14,9 @@ import 'common_test_utils.dart';
 final String testRootDir = Platform.script.resolve('.').toFilePath();
 
 runTestCase(
-    Uri source, List<String> experimentalFlags, bool enableNullSafety) async {
+    Uri source, List<String> experimentalFlags, bool soundNullSafety) async {
   final target =
-      TestingDart2jsTarget(TargetFlags(enableNullSafety: enableNullSafety));
+      TestingDart2jsTarget(TargetFlags(enableNullSafety: soundNullSafety));
   Component component = await compileTestCaseToKernelProgram(source,
       target: target, experimentalFlags: experimentalFlags);
 
@@ -33,13 +33,11 @@ main() {
         in testCasesDir.listSync(recursive: true, followLinks: false)) {
       final path = entry.path;
       if (path.endsWith('.dart')) {
-        final bool enableNullSafety = path.endsWith('_nnbd_strong.dart');
-        final bool enableNNBD = enableNullSafety || path.endsWith('_nnbd.dart');
-        final List<String> experimentalFlags = [
-          if (enableNNBD) 'non-nullable',
-        ];
-        test(path,
-            () => runTestCase(entry.uri, experimentalFlags, enableNullSafety));
+        final bool unsoundNullSafety = path.endsWith('_unsound.dart');
+        test(
+            path,
+            () => runTestCase(
+                entry.uri, const ['non-nullable'], !unsoundNullSafety));
       }
     }
   }, timeout: Timeout.none);