[cfe] Remove unnecessary_null_comparison code

The frontend is now run with sound null safety so these are no longer needed.

TEST=existing

Change-Id: I6c1776845854695ff34e310a3bb5bc9d86715f06
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/307901
Reviewed-by: Jens Johansen <jensj@google.com>
Reviewed-by: Srujan Gaddam <srujzs@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Commit-Queue: Johnni Winther <johnniwinther@google.com>

pkg/_fe_analyzer_shared/lib/src/base/errors.dart

@@ -53,11 +53,7 @@ abstract class ErrorCode {
     required String problemMessage,
     required this.uniqueName,
   })  : _correctionMessage = correctionMessage,
-        _problemMessage = problemMessage,
+        _problemMessage = problemMessage;
-        // ignore: unnecessary_null_comparison
-        assert(hasPublishedDocs != null),
-        // ignore: unnecessary_null_comparison
-        assert(isUnresolvedIdentifier != null);
 
   /**
    * The template used to create the correction to be displayed for this error,

pkg/_fe_analyzer_shared/lib/src/messages/codes_generated.dart

@@ -1501,8 +1501,7 @@ const Code<Message Function(String nameOKEmpty)> codeConstEvalDeferredLibrary =
 
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 Message _withArgumentsConstEvalDeferredLibrary(String nameOKEmpty) {
-  // ignore: unnecessary_null_comparison
+  if (nameOKEmpty.isEmpty) nameOKEmpty = '(unnamed)';
-  if (nameOKEmpty == null || nameOKEmpty.isEmpty) nameOKEmpty = '(unnamed)';
   return new Message(codeConstEvalDeferredLibrary,
       problemMessage:
           """'${nameOKEmpty}' can't be used in a constant expression because it's marked as 'deferred' which means it isn't available until loaded.""",
@@ -1588,8 +1587,7 @@ const Code<Message Function(String stringOKEmpty)>
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 Message _withArgumentsConstEvalFailedAssertionWithMessage(
     String stringOKEmpty) {
-  // ignore: unnecessary_null_comparison
+  if (stringOKEmpty.isEmpty) stringOKEmpty = '(empty)';
-  if (stringOKEmpty == null || stringOKEmpty.isEmpty) stringOKEmpty = '(empty)';
   return new Message(codeConstEvalFailedAssertionWithMessage,
       problemMessage:
           """This assertion failed with message: ${stringOKEmpty}""",
@@ -1622,8 +1620,7 @@ const Code<Message Function(String nameOKEmpty)> codeConstEvalGetterNotFound =
 
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 Message _withArgumentsConstEvalGetterNotFound(String nameOKEmpty) {
-  // ignore: unnecessary_null_comparison
+  if (nameOKEmpty.isEmpty) nameOKEmpty = '(unnamed)';
-  if (nameOKEmpty == null || nameOKEmpty.isEmpty) nameOKEmpty = '(unnamed)';
   return new Message(codeConstEvalGetterNotFound,
       problemMessage: """Variable get not found: '${nameOKEmpty}'""",
       arguments: {'nameOKEmpty': nameOKEmpty});
@@ -1646,8 +1643,7 @@ const Code<Message Function(String nameOKEmpty)>
 
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 Message _withArgumentsConstEvalInvalidStaticInvocation(String nameOKEmpty) {
-  // ignore: unnecessary_null_comparison
+  if (nameOKEmpty.isEmpty) nameOKEmpty = '(unnamed)';
-  if (nameOKEmpty == null || nameOKEmpty.isEmpty) nameOKEmpty = '(unnamed)';
   return new Message(codeConstEvalInvalidStaticInvocation,
       problemMessage:
           """The invocation of '${nameOKEmpty}' is not allowed in a constant expression.""",
@@ -1704,8 +1700,7 @@ const Code<Message Function(String nameOKEmpty)>
 
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 Message _withArgumentsConstEvalNonConstantVariableGet(String nameOKEmpty) {
-  // ignore: unnecessary_null_comparison
+  if (nameOKEmpty.isEmpty) nameOKEmpty = '(unnamed)';
-  if (nameOKEmpty == null || nameOKEmpty.isEmpty) nameOKEmpty = '(unnamed)';
   return new Message(codeConstEvalNonConstantVariableGet,
       problemMessage:
           """The variable '${nameOKEmpty}' is not a constant, only constant expressions are allowed.""",
@@ -1809,8 +1804,7 @@ const Code<Message Function(String stringOKEmpty)>
 
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 Message _withArgumentsConstEvalUnhandledCoreException(String stringOKEmpty) {
-  // ignore: unnecessary_null_comparison
+  if (stringOKEmpty.isEmpty) stringOKEmpty = '(empty)';
-  if (stringOKEmpty == null || stringOKEmpty.isEmpty) stringOKEmpty = '(empty)';
   return new Message(codeConstEvalUnhandledCoreException,
       problemMessage: """Unhandled core exception: ${stringOKEmpty}""",
       arguments: {'stringOKEmpty': stringOKEmpty});
@@ -2464,18 +2458,8 @@ const Code<
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 Message _withArgumentsDillOutlineSummary(
     int count, int count2, num _num1, num _num2, num _num3) {
-  // ignore: unnecessary_null_comparison
-  if (count == null) throw 'No count provided';
-  // ignore: unnecessary_null_comparison
-  if (count2 == null) throw 'No count provided';
-  // ignore: unnecessary_null_comparison
-  if (_num1 == null) throw 'No number provided';
   String num1 = _num1.toStringAsFixed(3);
-  // ignore: unnecessary_null_comparison
-  if (_num2 == null) throw 'No number provided';
   String num2 = _num2.toStringAsFixed(3).padLeft(12);
-  // ignore: unnecessary_null_comparison
-  if (_num3 == null) throw 'No number provided';
   String num3 = _num3.toStringAsFixed(3).padLeft(12);
   return new Message(codeDillOutlineSummary,
       problemMessage:
@@ -4070,8 +4054,6 @@ Message _withArgumentsExplicitExtensionTypeArgumentMismatch(
     String name, int count) {
   if (name.isEmpty) throw 'No name provided';
   name = demangleMixinApplicationName(name);
-  // ignore: unnecessary_null_comparison
-  if (count == null) throw 'No count provided';
   return new Message(codeExplicitExtensionTypeArgumentMismatch,
       problemMessage:
           """Explicit extension application of extension '${name}' takes '${count}' type argument(s).""",
@@ -4917,10 +4899,6 @@ const Code<Message Function(int count, int count2)>
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 Message _withArgumentsFfiNativeUnexpectedNumberOfParameters(
     int count, int count2) {
-  // ignore: unnecessary_null_comparison
-  if (count == null) throw 'No count provided';
-  // ignore: unnecessary_null_comparison
-  if (count2 == null) throw 'No count provided';
   return new Message(codeFfiNativeUnexpectedNumberOfParameters,
       problemMessage:
           """Unexpected number of FfiNative annotation parameters. Expected ${count} but has ${count2}.""",
@@ -4946,10 +4924,6 @@ const Code<Message Function(int count, int count2)>
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 Message _withArgumentsFfiNativeUnexpectedNumberOfParametersWithReceiver(
     int count, int count2) {
-  // ignore: unnecessary_null_comparison
-  if (count == null) throw 'No count provided';
-  // ignore: unnecessary_null_comparison
-  if (count2 == null) throw 'No count provided';
   return new Message(codeFfiNativeUnexpectedNumberOfParametersWithReceiver,
       problemMessage:
           """Unexpected number of FfiNative annotation parameters. Expected ${count} but has ${count2}. FfiNative instance method annotation must have receiver as first argument.""",
@@ -5871,8 +5845,6 @@ const Code<Message Function(String name, int count)> codeImplementsRepeated =
 Message _withArgumentsImplementsRepeated(String name, int count) {
   if (name.isEmpty) throw 'No name provided';
   name = demangleMixinApplicationName(name);
-  // ignore: unnecessary_null_comparison
-  if (count == null) throw 'No count provided';
   return new Message(codeImplementsRepeated,
       problemMessage: """'${name}' can only be implemented once.""",
       correctionMessage: """Try removing ${count} of the occurrences.""",
@@ -6430,10 +6402,6 @@ const Code<Message Function(int count, int count2)>
 
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 Message _withArgumentsInstantiationTooFewArguments(int count, int count2) {
-  // ignore: unnecessary_null_comparison
-  if (count == null) throw 'No count provided';
-  // ignore: unnecessary_null_comparison
-  if (count2 == null) throw 'No count provided';
   return new Message(codeInstantiationTooFewArguments,
       problemMessage:
           """Too few type arguments: ${count} required, ${count2} given.""",
@@ -6460,10 +6428,6 @@ const Code<Message Function(int count, int count2)>
 
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 Message _withArgumentsInstantiationTooManyArguments(int count, int count2) {
-  // ignore: unnecessary_null_comparison
-  if (count == null) throw 'No count provided';
-  // ignore: unnecessary_null_comparison
-  if (count2 == null) throw 'No count provided';
   return new Message(codeInstantiationTooManyArguments,
       problemMessage:
           """Too many type arguments: ${count} allowed, but ${count2} found.""",
@@ -8621,10 +8585,6 @@ const Code<Message Function(int count, int count2)> codeLanguageVersionTooHigh =
 
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 Message _withArgumentsLanguageVersionTooHigh(int count, int count2) {
-  // ignore: unnecessary_null_comparison
-  if (count == null) throw 'No count provided';
-  // ignore: unnecessary_null_comparison
-  if (count2 == null) throw 'No count provided';
   return new Message(codeLanguageVersionTooHigh,
       problemMessage:
           """The specified language version is too high. The highest supported language version is ${count}.${count2}.""",
@@ -11849,18 +11809,8 @@ const Code<
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 Message _withArgumentsSourceBodySummary(
     int count, int count2, num _num1, num _num2, num _num3) {
-  // ignore: unnecessary_null_comparison
-  if (count == null) throw 'No count provided';
-  // ignore: unnecessary_null_comparison
-  if (count2 == null) throw 'No count provided';
-  // ignore: unnecessary_null_comparison
-  if (_num1 == null) throw 'No number provided';
   String num1 = _num1.toStringAsFixed(3);
-  // ignore: unnecessary_null_comparison
-  if (_num2 == null) throw 'No number provided';
   String num2 = _num2.toStringAsFixed(3).padLeft(12);
-  // ignore: unnecessary_null_comparison
-  if (_num3 == null) throw 'No number provided';
   String num3 = _num3.toStringAsFixed(3).padLeft(12);
   return new Message(codeSourceBodySummary,
       problemMessage:
@@ -11904,18 +11854,8 @@ const Code<
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 Message _withArgumentsSourceOutlineSummary(
     int count, int count2, num _num1, num _num2, num _num3) {
-  // ignore: unnecessary_null_comparison
-  if (count == null) throw 'No count provided';
-  // ignore: unnecessary_null_comparison
-  if (count2 == null) throw 'No count provided';
-  // ignore: unnecessary_null_comparison
-  if (_num1 == null) throw 'No number provided';
   String num1 = _num1.toStringAsFixed(3);
-  // ignore: unnecessary_null_comparison
-  if (_num2 == null) throw 'No number provided';
   String num2 = _num2.toStringAsFixed(3).padLeft(12);
-  // ignore: unnecessary_null_comparison
-  if (_num3 == null) throw 'No number provided';
   String num3 = _num3.toStringAsFixed(3).padLeft(12);
   return new Message(codeSourceOutlineSummary,
       problemMessage:
@@ -12553,10 +12493,6 @@ const Code<Message Function(int count, int count2)> codeTooFewArguments =
 
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 Message _withArgumentsTooFewArguments(int count, int count2) {
-  // ignore: unnecessary_null_comparison
-  if (count == null) throw 'No count provided';
-  // ignore: unnecessary_null_comparison
-  if (count2 == null) throw 'No count provided';
   return new Message(codeTooFewArguments,
       problemMessage:
           """Too few positional arguments: ${count} required, ${count2} given.""",
@@ -12583,10 +12519,6 @@ const Code<Message Function(int count, int count2)> codeTooManyArguments =
 
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 Message _withArgumentsTooManyArguments(int count, int count2) {
-  // ignore: unnecessary_null_comparison
-  if (count == null) throw 'No count provided';
-  // ignore: unnecessary_null_comparison
-  if (count2 == null) throw 'No count provided';
   return new Message(codeTooManyArguments,
       problemMessage:
           """Too many positional arguments: ${count} allowed, but ${count2} found.""",
@@ -12628,8 +12560,6 @@ const Code<Message Function(int count)> codeTypeArgumentMismatch =
 
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 Message _withArgumentsTypeArgumentMismatch(int count) {
-  // ignore: unnecessary_null_comparison
-  if (count == null) throw 'No count provided';
   return new Message(codeTypeArgumentMismatch,
       problemMessage: """Expected ${count} type arguments.""",
       arguments: {'count': count});

pkg/_fe_analyzer_shared/lib/src/parser/parser_impl.dart

@@ -1897,8 +1897,6 @@ class Parser {
   /// ```
   Token parseFormalParameter(
       Token token, FormalParameterKind parameterKind, MemberKind memberKind) {
-    // ignore: unnecessary_null_comparison
-    assert(parameterKind != null);
     token = parseMetadataStar(token);
 
     Token? skippedNonRequiredRequired;
@@ -3159,14 +3157,10 @@ class Parser {
   /// identifier in the given [context], create a synthetic identifier, report
   /// an error, and return the synthetic identifier.
   Token ensureIdentifier(Token token, IdentifierContext context) {
-    // ignore: unnecessary_null_comparison
-    assert(context != null);
     _tryRewriteNewToIdentifier(token, context);
     Token identifier = token.next!;
     if (identifier.kind != IDENTIFIER_TOKEN) {
       identifier = context.ensureIdentifier(token, this);
-      // ignore: unnecessary_null_comparison
-      assert(identifier != null);
       assert(identifier.isKeywordOrIdentifier);
     }
     listener.handleIdentifier(identifier, context);
@@ -3224,14 +3218,10 @@ class Parser {
   /// to use the token as an identifier, even if it isn't a valid identifier.
   Token ensureIdentifierPotentiallyRecovered(
       Token token, IdentifierContext context, bool isRecovered) {
-    // ignore: unnecessary_null_comparison
-    assert(context != null);
     Token identifier = token.next!;
     if (identifier.kind != IDENTIFIER_TOKEN) {
       identifier = context.ensureIdentifierPotentiallyRecovered(
           token, this, isRecovered);
-      // ignore: unnecessary_null_comparison
-      assert(identifier != null);
       assert(identifier.isKeywordOrIdentifier);
     }
     listener.handleIdentifier(identifier, context);

pkg/_fe_analyzer_shared/lib/src/parser/type_info_impl.dart

@@ -521,10 +521,7 @@ class ComplexTypeInfo implements TypeInfo {
 
   ComplexTypeInfo(Token beforeStart, this.typeArguments)
       : this.start = beforeStart.next!,
-        recovered = typeArguments.recovered {
+        recovered = typeArguments.recovered;
-    // ignore: unnecessary_null_comparison
-    assert(typeArguments != null);
-  }
 
   ComplexTypeInfo._nonNullable(
       this.start,
@@ -1226,10 +1223,6 @@ class ComplexTypeParamOrArgInfo extends TypeParamOrArgInfo {
   ComplexTypeParamOrArgInfo(
       Token token, this.inDeclaration, this.allowsVariance)
       : assert(optional('<', token.next!)),
-        // ignore: unnecessary_null_comparison
-        assert(inDeclaration != null),
-        // ignore: unnecessary_null_comparison
-        assert(allowsVariance != null),
         start = token.next!;
 
   /// Parse the tokens and return the receiver or [noTypeParamOrArg] if there

pkg/_fe_analyzer_shared/lib/src/scanner/scanner.dart

@@ -85,8 +85,6 @@ ScannerResult scanString(String source,
     {ScannerConfiguration? configuration,
     bool includeComments = false,
     LanguageVersionChanged? languageVersionChanged}) {
-  // ignore: unnecessary_null_comparison
-  assert(source != null, 'source must not be null');
   StringScanner scanner = new StringScanner(source,
       configuration: configuration,
       includeComments: includeComments,

pkg/_fe_analyzer_shared/lib/src/testing/annotated_code_helper.dart

@@ -37,9 +37,7 @@ class Annotation {
 
   Annotation(this.index, this.lineNo, this.columnNo, this.offset, this.prefix,
       this.text, this.suffix)
-      // ignore: unnecessary_null_comparison
+      : assert(offset >= 0);
-      : assert(offset != null),
-        assert(offset >= 0);
 
   @override
   String toString() =>

pkg/_fe_analyzer_shared/lib/src/testing/id.dart

@@ -305,11 +305,7 @@ class NodeId implements Id {
   @override
   final IdKind kind;
 
-  const NodeId(this.value, this.kind)
+  const NodeId(this.value, this.kind) : assert(value >= 0);
-      :
-        // ignore: unnecessary_null_comparison
-        assert(value != null),
-        assert(value >= 0);
 
   @override
   bool get isGlobal => false;

pkg/_fe_analyzer_shared/lib/src/testing/id_generation.dart

@@ -43,12 +43,6 @@ Map<Uri, List<Annotation>> computeAnnotationsPerUri<T>(
   actualData
       .forEach((String marker, Map<Uri, Map<Id, ActualData<T>>> dataPerUri) {
     dataPerUri.forEach((Uri uri, Map<Id, ActualData<T>> dataMap) {
-      // ignore: unnecessary_null_comparison
-      if (uri == null) {
-        // TODO(johnniwinther): Avoid `null` URIs.
-        assert(dataMap.isEmpty, "Non-empty data for `null` uri: $dataMap");
-        return;
-      }
       uriSet.add(uri);
       dataMap.forEach((Id id, ActualData<T> data) {
         Map<Id, Map<String, ActualData<T>>> actualDataPerId =
@@ -88,9 +82,6 @@ List<Annotation> _computeAnnotations<T>(
     bool sortMarkers = true,
     Annotation? Function(Annotation? expected, Annotation? actual)? createDiff,
     bool forceUpdate = false}) {
-  // ignore: unnecessary_null_comparison
-  assert(annotatedCode != null);
-
   Annotation createAnnotationFromData(
       ActualData<T> actualData, Annotation? annotation) {
     String getIndentationFromOffset(int offset) {

pkg/_fe_analyzer_shared/lib/src/testing/id_testing.dart

@@ -225,8 +225,6 @@ void computeExpectedMap(Uri sourceUri, String filename, AnnotatedCode code,
 
   split.forEach((String marker, AnnotatedCode code) {
     MemberAnnotations<IdValue> fileAnnotations = maps[marker]!;
-    // ignore: unnecessary_null_comparison
-    assert(fileAnnotations != null, "No annotations for $marker in $maps");
     Map<Id, IdValue> expectedValues = fileAnnotations[sourceUri]!;
     for (Annotation annotation in code.annotations) {
       String text = annotation.text;
@@ -940,13 +938,9 @@ Future<void> runTests<T>(Directory dataDir,
               actualData[marker] = {};
 
           void addActualData(Uri uri, Map<Id, ActualData<T>> actualData) {
-            assert(
+            assert(testData.code.containsKey(uri) || actualData.isEmpty,
-                // ignore: unnecessary_null_comparison
-                uri != null && testData.code.containsKey(uri) ||
-                    actualData.isEmpty,
                 "Unexpected data ${actualData} for $uri");
-            // ignore: unnecessary_null_comparison
+            if (actualData.isEmpty) {
-            if (uri == null || actualData.isEmpty) {
               // TODO(johnniwinther): Avoid collecting data without
               //  invalid uris.
               return;
@@ -969,8 +963,6 @@ Future<void> runTests<T>(Directory dataDir,
             dataInterpreter!,
             forceUpdate: forceUpdate);
         annotations.forEach((Uri uri, List<Annotation> annotations) {
-          // ignore: unnecessary_null_comparison
-          assert(uri != null, "Annotations without uri: $annotations");
           AnnotatedCode? code = testData.code[uri];
           assert(code != null,
               "No annotated code for $uri with annotations: $annotations");

pkg/_fe_analyzer_shared/lib/src/util/colors.dart

@@ -87,8 +87,6 @@ bool get enableColors => _enableColors ??= _computeEnableColors();
 /// Allows the client to override the decision of whether to disable ANSI
 /// colors.
 void set enableColors(bool value) {
-  // ignore: unnecessary_null_comparison
-  assert(value != null);
   _enableColors = value;
 }
 

pkg/_fe_analyzer_shared/test/id_generation_test.dart

@@ -551,9 +551,7 @@ void testGeneral<T>(DataInterpreter<T> dataInterpreter, String text,
       code.annotatedCode, code.sourceCode, annotations[mainUri]!);
   String actualResult = generated.toText();
   if (expectedResult != actualResult) {
-    print("Unexpected result for '$text'"
+    print("Unexpected result for '$text' with actualData=$actualData");
-        // ignore: unnecessary_null_comparison
-        "${actualData != null ? ' with actualData=$actualData' : ''}");
     print('---expected-------------------------------------------------------');
     print(expectedResult);
     print('---actual---------------------------------------------------------');

pkg/_fe_analyzer_shared/test/mini_ast.dart

@@ -177,8 +177,6 @@ Statement forEachWithNonVariable(Expression iterable, List<Statement> body) {
 ///     }
 Statement forEachWithVariableDecl(
     Var variable, Expression iterable, List<Statement> body) {
-  // ignore: unnecessary_null_comparison
-  assert(variable != null);
   return new ForEach._(variable, iterable, block(body), true,
       location: computeLocation());
 }
@@ -193,8 +191,6 @@ Statement forEachWithVariableDecl(
 ///     }
 Statement forEachWithVariableSet(
     Var variable, Expression iterable, List<Statement> body) {
-  // ignore: unnecessary_null_comparison
-  assert(variable != null);
   var location = computeLocation();
   return new ForEach._(
       variable, iterable, Block._(body, location: location), false,

pkg/_js_interop_checks/lib/js_interop_checks.dart

@@ -792,8 +792,7 @@ class JsInteropChecks extends RecursiveVisitor {
 
   /// Reports an error if [functionNode] has named parameters.
   void _checkNoNamedParameters(FunctionNode functionNode) {
-    // ignore: unnecessary_null_comparison
+    if (functionNode.namedParameters.isNotEmpty) {
-    if (functionNode != null && functionNode.namedParameters.isNotEmpty) {
       final firstNamedParam = functionNode.namedParameters[0];
       _reporter.report(
           messageJsInteropNamedParameters,

pkg/front_end/lib/src/api_prototype/experimental_flags.dart

@@ -158,8 +158,6 @@ Version getExperimentEnabledVersionInLibrary(ExperimentalFlag flag,
     }
     version ??= flag.experimentEnabledVersion;
   }
-  // ignore: unnecessary_null_comparison
-  assert(version != null, "No version for enabling $flag in $canonicalUri.");
   return version;
 }
 

pkg/front_end/lib/src/api_prototype/language_version.dart

@@ -40,14 +40,11 @@ Future<VersionAndPackageUri> languageVersionForUri(
     bool good = false;
     late final int currentSdkVersionMajor;
     late final int currentSdkVersionMinor;
-    // ignore: unnecessary_null_comparison
+    List<String> dotSeparatedParts = currentSdkVersion.split(".");
-    if (currentSdkVersion != null) {
+    if (dotSeparatedParts.length >= 2) {
-      List<String> dotSeparatedParts = currentSdkVersion.split(".");
+      currentSdkVersionMajor = int.parse(dotSeparatedParts[0]);
-      if (dotSeparatedParts.length >= 2) {
+      currentSdkVersionMinor = int.parse(dotSeparatedParts[1]);
-        currentSdkVersionMajor = int.parse(dotSeparatedParts[0]);
+      good = true;
-        currentSdkVersionMinor = int.parse(dotSeparatedParts[1]);
-        good = true;
-      }
     }
     if (!good) {
       throw new StateError("Unparsable sdk version given: $currentSdkVersion");
@@ -67,9 +64,7 @@ Future<VersionAndPackageUri> languageVersionForUri(
     Uri packageUri = uri;
     if (!packageUri.isScheme('dart') &&
         !packageUri.isScheme('package') &&
-        package != null &&
+        package != null) {
-        // ignore: unnecessary_null_comparison
-        package.name != null) {
       packageUri = new Uri(scheme: 'package', path: package.name);
     }
 

pkg/front_end/lib/src/api_prototype/lowering_predicates.dart

@@ -31,8 +31,6 @@ export '../fasta/kernel/constructor_tearoff_lowering.dart'
 /// The default value of this field is `null`.
 bool isLateLoweredField(Field node) {
   return node.isInternalImplementation &&
-      // ignore: unnecessary_null_comparison
-      node.name != null &&
       node.name.text.startsWith(lateFieldPrefix) &&
       !node.name.text.endsWith(lateIsSetSuffix);
 }
@@ -87,8 +85,6 @@ Name extractFieldNameFromLateLoweredField(Field node) {
 /// The default value of this field is `false`.
 bool isLateLoweredIsSetField(Field node) {
   return node.isInternalImplementation &&
-      // ignore: unnecessary_null_comparison
-      node.name != null &&
       node.name.text.startsWith(lateFieldPrefix) &&
       node.name.text.endsWith(lateIsSetSuffix);
 }

pkg/front_end/lib/src/api_unstable/ddc.dart

@@ -88,9 +88,7 @@ class DdcResult {
   final Set<Library>? neededDillLibraries;
 
   DdcResult(this.component, this.sdkSummary, this.additionalDills,
-      this.classHierarchy, this.neededDillLibraries)
+      this.classHierarchy, this.neededDillLibraries);
-      // ignore: unnecessary_null_comparison
-      : assert(classHierarchy != null);
 
   Set<Library> computeLibrariesFromDill() {
     Set<Library> librariesFromDill = new Set<Library>();
@@ -123,8 +121,6 @@ InitializedCompilerState initializeCompiler(
     Map<ExperimentalFlag, bool>? explicitExperimentalFlags,
     Map<String, String>? environmentDefines,
     required NnbdMode nnbdMode}) {
-  // ignore: unnecessary_null_comparison
-  assert(nnbdMode != null, "No NnbdMode provided.");
   additionalDills.sort((a, b) => a.toString().compareTo(b.toString()));
 
   if (oldState != null &&

pkg/front_end/lib/src/base/processed_options.dart

@@ -439,8 +439,7 @@ class ProcessedOptions {
   Future<List<Component>> loadAdditionalDills(CanonicalName? nameRoot) async {
     if (_additionalDillComponents == null) {
       List<Uri> uris = _raw.additionalDills;
-      // ignore: unnecessary_null_comparison
+      if (uris.isEmpty) return const <Component>[];
-      if (uris == null || uris.isEmpty) return const <Component>[];
       // TODO(sigmund): throttle # of concurrent operations.
       List<List<int>?> allBytes = await Future.wait(
           uris.map((uri) => _readAsBytes(fileSystem.entityForUri(uri))));

pkg/front_end/lib/src/compute_platform_binaries_location.dart

@@ -125,14 +125,11 @@ Uri translateSdk(Uri uri) {
           if (sdkRoot == null) {
             sdkRoot = (options.sdkSummary ?? computePlatformBinariesLocation())
                 .resolve("../../");
-            // ignore: unnecessary_null_comparison
+            if (!isExistingFile(sdkRoot.resolve("lib/libraries.json"))) {
-            if (sdkRoot != null) {
+              if (isExistingFile(sdkRoot.resolve("sdk/lib/libraries.json"))) {
-              if (!isExistingFile(sdkRoot.resolve("lib/libraries.json"))) {
+                sdkRoot = sdkRoot.resolve("sdk/");
-                if (isExistingFile(sdkRoot.resolve("sdk/lib/libraries.json"))) {
+              } else {
-                  sdkRoot = sdkRoot.resolve("sdk/");
+                sdkRoot = null;
-                } else {
-                  sdkRoot = null;
-                }
               }
             }
           }

pkg/front_end/lib/src/fasta/builder/formal_parameter_builder.dart

@@ -193,8 +193,6 @@ class FormalParameterBuilder extends ModifierBuilderImpl
   }
 
   FormalParameterBuilder forFormalParameterInitializerScope() {
-    // ignore: unnecessary_null_comparison
-    assert(variable != null);
     if (isInitializingFormal) {
       return new FormalParameterBuilder(
           metadata,

pkg/front_end/lib/src/fasta/builder/member_builder.dart

@@ -188,10 +188,7 @@ abstract class BuilderClassMember implements ClassMember {
   String get fullName {
     String suffix = isSetter ? "=" : "";
     String className = classBuilder.fullNameForErrors;
-    // ignore: unnecessary_null_comparison
+    return "${className}.${fullNameForErrors}$suffix";
-    return className == null
-        ? "${fullNameForErrors}$suffix"
-        : "${className}.${fullNameForErrors}$suffix";
   }
 
   @override

pkg/front_end/lib/src/fasta/builder/named_type_builder.dart

@@ -382,9 +382,7 @@ abstract class NamedTypeBuilder extends TypeBuilder {
     if (declaration!.isTypeVariable) {
       message =
           templateSupertypeIsTypeVariable.withArguments(fullNameForErrors);
-    } else
+    } else if (type.nullability == Nullability.nullable) {
-    // ignore: unnecessary_null_comparison
-    if (type != null && type.nullability == Nullability.nullable) {
       message = templateSupertypeIsNullableAliased.withArguments(
           fullNameForErrors, type, library.isNonNullableByDefault);
     } else {

pkg/front_end/lib/src/fasta/builder/nullability_builder.dart

@@ -55,9 +55,6 @@ class NullabilityBuilder {
   }
 
   Nullability build(LibraryBuilder libraryBuilder) {
-    // ignore: unnecessary_null_comparison
-    assert(libraryBuilder != null);
-
     switch (_syntacticNullability) {
       case SyntacticNullability.legacy:
         return Nullability.legacy;

pkg/front_end/lib/src/fasta/builder/type_declaration_builder.dart

@@ -76,9 +76,7 @@ abstract class TypeDeclarationBuilderImpl extends ModifierBuilderImpl
 
   TypeDeclarationBuilderImpl(
       this.metadata, this.modifiers, this.name, Builder? parent, int charOffset)
-      // ignore: unnecessary_null_comparison
+      : super(parent, charOffset);
-      : assert(modifiers != null),
-        super(parent, charOffset);
 
   @override
   TypeDeclarationBuilder get origin => this;

pkg/front_end/lib/src/fasta/crash.dart

@@ -98,20 +98,17 @@ Future<T> reportCrash<T>(error, StackTrace trace,
           new Crash(uri, charOffset, error, trace).._hasBeenReported = true,
           trace);
     }
-    // ignore: unnecessary_null_comparison
+    await note("\nSending crash report data");
-    if (request != null) {
+    request.persistentConnection = false;
-      await note("\nSending crash report data");
+    request.bufferOutput = false;
-      request.persistentConnection = false;
+    String? host = request.connectionInfo?.remoteAddress.host;
-      request.bufferOutput = false;
+    int? port = request.connectionInfo?.remotePort;
-      String? host = request.connectionInfo?.remoteAddress.host;
+    await note(" to $host:$port");
-      int? port = request.connectionInfo?.remotePort;
+    await request
-      await note(" to $host:$port");
+      ..headers.contentType = ContentType.json
-      await request
+      ..write(json);
-        ..headers.contentType = ContentType.json
+    await request.close();
-        ..write(json);
+    await note(".");
-      await request.close();
-      await note(".");
-    }
   } catch (e, s) {
     await note("\n${safeToString(e)}\n$s\n");
     await note("\n\n\nFE::ERROR::$json\n\n\n");

pkg/front_end/lib/src/fasta/dill/dill_class_builder.dart

@@ -234,8 +234,7 @@ int computeModifiers(Class cls) {
   if (cls.isAbstract) {
     modifiers |= abstractMask;
   }
-  // ignore: unnecessary_null_comparison
+  if (cls.isMixinApplication) {
-  if (cls.isMixinApplication && cls.name != null) {
     modifiers |= namedMixinApplicationMask;
   }
   return modifiers;

pkg/front_end/lib/src/fasta/dill/dill_library_builder.dart

@@ -340,8 +340,6 @@ class DillLibraryBuilder extends LibraryBuilderImpl {
       String name;
       if (sourceBuildersMap?.containsKey(reference) == true) {
         declaration = sourceBuildersMap![reference]!;
-        // ignore: unnecessary_null_comparison
-        assert(declaration != null);
         if (declaration is ModifierBuilder) {
           name = declaration.name!;
         } else {
@@ -395,14 +393,6 @@ class DillLibraryBuilder extends LibraryBuilderImpl {
               library.exportScope.lookupLocalMember(name, setter: false)!;
           exportScope.addLocalMember(name, declaration, setter: false);
         }
-        // ignore: unnecessary_null_comparison
-        if (declaration == null) {
-          internalProblem(
-              templateUnspecified.withArguments(
-                  "Exported element '$name' not found in '$libraryUri'."),
-              -1,
-              fileUri);
-        }
       }
 
       assert(

pkg/front_end/lib/src/fasta/dill/dill_loader.dart

@@ -32,7 +32,7 @@ import '../messages.dart'
         messagePlatformPrivateLibraryAccess,
         templateInternalProblemContextSeverity;
 
-import '../problems.dart' show internalProblem, unhandled;
+import '../problems.dart' show internalProblem;
 
 import '../source/source_loader.dart' show SourceLoader;
 
@@ -118,7 +118,6 @@ class DillLoader extends Loader {
     DillLibraryBuilder? libraryBuilder = _builders[uri];
     if (libraryBuilder == null) {
       libraryBuilder = _knownLibraryBuilders.remove(uri);
-      // ignore: unnecessary_null_comparison
       assert(libraryBuilder != null, "No library found for $uri.");
       _builders[uri] = libraryBuilder!;
       assert(libraryBuilder.loader == this);
@@ -311,10 +310,6 @@ severity: $severity
   }
 
   void buildOutline(DillLibraryBuilder builder) {
-    // ignore: unnecessary_null_comparison
-    if (builder.library == null) {
-      unhandled("null", "builder.library", 0, builder.fileUri);
-    }
     builder.markAsReadyToBuild();
   }
 

pkg/front_end/lib/src/fasta/dill/dill_member_builder.dart

@@ -262,9 +262,7 @@ class DillClassMember extends BuilderClassMember {
   @override
   final bool forSetter;
 
-  DillClassMember(this.memberBuilder, {required this.forSetter})
+  DillClassMember(this.memberBuilder, {required this.forSetter});
-      // ignore: unnecessary_null_comparison
-      : assert(forSetter != null);
 
   @override
   bool get isSourceDeclaration => false;

pkg/front_end/lib/src/fasta/dill/dill_target.dart

@@ -45,13 +45,7 @@ class DillTarget extends TargetImplementation {
   final Benchmarker? benchmarker;
 
   DillTarget(this.ticker, this.uriTranslator, this.backendTarget,
-      {this.benchmarker})
+      {this.benchmarker}) {
-      // ignore: unnecessary_null_comparison
-      : assert(ticker != null),
-        // ignore: unnecessary_null_comparison
-        assert(uriTranslator != null),
-        // ignore: unnecessary_null_comparison
-        assert(backendTarget != null) {
     loader = new DillLoader(this);
   }
 

pkg/front_end/lib/src/fasta/fasta_codes_cfe_generated.dart

@@ -589,8 +589,7 @@ Message _withArgumentsConstEvalInvalidBinaryOperandType(
     DartType _type,
     DartType _type2,
     bool isNonNullableByDefault) {
-  // ignore: unnecessary_null_comparison
+  if (stringOKEmpty.isEmpty) stringOKEmpty = '(empty)';
-  if (stringOKEmpty == null || stringOKEmpty.isEmpty) stringOKEmpty = '(empty)';
   TypeLabeler labeler = new TypeLabeler(isNonNullableByDefault);
   List<Object> constantParts = labeler.labelConstant(_constant);
   List<Object> typeParts = labeler.labelType(_type);
@@ -673,8 +672,7 @@ const Code<
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 Message _withArgumentsConstEvalInvalidMethodInvocation(
     String stringOKEmpty, Constant _constant, bool isNonNullableByDefault) {
-  // ignore: unnecessary_null_comparison
+  if (stringOKEmpty.isEmpty) stringOKEmpty = '(empty)';
-  if (stringOKEmpty == null || stringOKEmpty.isEmpty) stringOKEmpty = '(empty)';
   TypeLabeler labeler = new TypeLabeler(isNonNullableByDefault);
   List<Object> constantParts = labeler.labelConstant(_constant);
   String constant = constantParts.join();
@@ -711,8 +709,7 @@ const Code<
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 Message _withArgumentsConstEvalInvalidPropertyGet(
     String stringOKEmpty, Constant _constant, bool isNonNullableByDefault) {
-  // ignore: unnecessary_null_comparison
+  if (stringOKEmpty.isEmpty) stringOKEmpty = '(empty)';
-  if (stringOKEmpty == null || stringOKEmpty.isEmpty) stringOKEmpty = '(empty)';
   TypeLabeler labeler = new TypeLabeler(isNonNullableByDefault);
   List<Object> constantParts = labeler.labelConstant(_constant);
   String constant = constantParts.join();
@@ -749,8 +746,7 @@ const Code<
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 Message _withArgumentsConstEvalInvalidRecordIndexGet(
     String stringOKEmpty, Constant _constant, bool isNonNullableByDefault) {
-  // ignore: unnecessary_null_comparison
+  if (stringOKEmpty.isEmpty) stringOKEmpty = '(empty)';
-  if (stringOKEmpty == null || stringOKEmpty.isEmpty) stringOKEmpty = '(empty)';
   TypeLabeler labeler = new TypeLabeler(isNonNullableByDefault);
   List<Object> constantParts = labeler.labelConstant(_constant);
   String constant = constantParts.join();
@@ -787,8 +783,7 @@ const Code<
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 Message _withArgumentsConstEvalInvalidRecordNameGet(
     String stringOKEmpty, Constant _constant, bool isNonNullableByDefault) {
-  // ignore: unnecessary_null_comparison
+  if (stringOKEmpty.isEmpty) stringOKEmpty = '(empty)';
-  if (stringOKEmpty == null || stringOKEmpty.isEmpty) stringOKEmpty = '(empty)';
   TypeLabeler labeler = new TypeLabeler(isNonNullableByDefault);
   List<Object> constantParts = labeler.labelConstant(_constant);
   String constant = constantParts.join();
@@ -2039,10 +2034,6 @@ const Code<
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 Message _withArgumentsIndexOutOfBoundInRecordIndexGet(
     int count, int count2, DartType _type, bool isNonNullableByDefault) {
-  // ignore: unnecessary_null_comparison
-  if (count == null) throw 'No count provided';
-  // ignore: unnecessary_null_comparison
-  if (count2 == null) throw 'No count provided';
   TypeLabeler labeler = new TypeLabeler(isNonNullableByDefault);
   List<Object> typeParts = labeler.labelType(_type);
   String type = typeParts.join();

pkg/front_end/lib/src/fasta/incremental_compiler.dart

@@ -1465,11 +1465,9 @@ class IncrementalCompiler implements IncrementalKernelGenerator {
       }
 
       if (childReplacementMap == null) return;
-      Builder replacement = childReplacementMap[declaration.name]!;
+      Builder? replacement = childReplacementMap[declaration.name];
       assert(
-          // ignore: unnecessary_null_comparison
+          replacement != null, "Didn't find the replacement for $typeBuilder");
-          replacement != null,
-          "Didn't find the replacement for $typeBuilder");
       typeBuilder.bind(
           parent as LibraryBuilder, replacement as TypeDeclarationBuilder);
     }
@@ -2366,18 +2364,7 @@ class ReusageResult {
       this.directlyInvalidated,
       this.invalidatedBecauseOfPackageUpdate,
       this.reusedLibraries,
-      this.partUriToParent)
+      this.partUriToParent);
-      :
-        // ignore: unnecessary_null_comparison
-        assert(notReusedLibraries != null),
-        // ignore: unnecessary_null_comparison
-        assert(directlyInvalidated != null),
-        // ignore: unnecessary_null_comparison
-        assert(invalidatedBecauseOfPackageUpdate != null),
-        // ignore: unnecessary_null_comparison
-        assert(reusedLibraries != null),
-        // ignore: unnecessary_null_comparison
-        assert(partUriToParent != null);
 }
 
 class ExperimentalInvalidation {
@@ -2386,13 +2373,7 @@ class ExperimentalInvalidation {
   final Set<Uri> missingSources;
 
   ExperimentalInvalidation(
-      this.rebuildBodies, this.originalNotReusedLibraries, this.missingSources)
+      this.rebuildBodies, this.originalNotReusedLibraries, this.missingSources);
-      // ignore: unnecessary_null_comparison
-      : assert(rebuildBodies != null),
-        // ignore: unnecessary_null_comparison
-        assert(originalNotReusedLibraries != null),
-        // ignore: unnecessary_null_comparison
-        assert(missingSources != null);
 }
 
 class IncrementalKernelTarget extends KernelTarget
@@ -2637,8 +2618,7 @@ class _InitializationFromUri extends _InitializationFromSdkSummary {
         context.options.fileSystem.entityForUri(initializeFromDillUri);
     if (await entity.exists()) {
       List<int> initializationBytes = await entity.readAsBytes();
-      // ignore: unnecessary_null_comparison
+      if (initializationBytes.isNotEmpty) {
-      if (initializationBytes != null && initializationBytes.isNotEmpty) {
         dillLoadedData.ticker.logMs("Read $initializeFromDillUri");
         data.initializationBytes = initializationBytes;
 

pkg/front_end/lib/src/fasta/kernel/body_builder.dart

@@ -424,8 +424,6 @@ class BodyBuilder extends StackListenerImpl
       }
     }
     scope = pop() as Scope;
-    // ignore: unnecessary_null_comparison
-    assert(scope != null);
   }
 
   void enterBreakTarget(int charOffset, [JumpTarget? target]) {
@@ -1497,20 +1495,11 @@ class BodyBuilder extends StackListenerImpl
       // set its inferredType field.  If type inference is disabled, reach to
       // the outermost parent to check if the node is a dead code.
       if (invocation.parent == null) continue;
-      // ignore: unnecessary_null_comparison
+      if (!invocation.hasBeenInferred) {
-      if (typeInferrer != null) {
+        if (allowFurtherDelays) {
-        if (!invocation.hasBeenInferred) {
+          delayedRedirectingFactoryInvocations.add(invocation);
-          if (allowFurtherDelays) {
-            delayedRedirectingFactoryInvocations.add(invocation);
-          }
-          continue;
         }
-      } else {
+        continue;
-        TreeNode? parent = invocation.parent;
-        while (parent is! Component && parent != null) {
-          parent = parent.parent;
-        }
-        if (parent == null) continue;
       }
       Expression? replacement = _resolveRedirectingFactoryTarget(
           invocation.target,
@@ -6400,8 +6389,7 @@ class BodyBuilder extends StackListenerImpl
       }
 
       List<DartType> typeArgumentsToCheck = const <DartType>[];
-      // ignore: unnecessary_null_comparison
+      if (typeArgumentBuilders.isNotEmpty) {
-      if (typeArgumentBuilders != null && typeArgumentBuilders.isNotEmpty) {
         typeArgumentsToCheck = new List.filled(
             typeArgumentBuilders.length, const DynamicType(),
             growable: false);
@@ -8925,8 +8913,6 @@ class BodyBuilder extends StackListenerImpl
   @override
   TypeBuilder validateTypeVariableUse(TypeBuilder typeBuilder,
       {required bool allowPotentiallyConstantType}) {
-    // ignore: unnecessary_null_comparison
-    assert(allowPotentiallyConstantType != null);
     _validateTypeVariableUseInternal(typeBuilder,
         allowPotentiallyConstantType: allowPotentiallyConstantType);
     return typeBuilder;
@@ -8934,8 +8920,6 @@ class BodyBuilder extends StackListenerImpl
 
   void _validateTypeVariableUseInternal(TypeBuilder? builder,
       {required bool allowPotentiallyConstantType}) {
-    // ignore: unnecessary_null_comparison
-    assert(allowPotentiallyConstantType != null);
     if (builder is NamedTypeBuilder) {
       if (builder.declaration!.isTypeVariable) {
         TypeVariableBuilder typeParameterBuilder =

pkg/front_end/lib/src/fasta/kernel/collections.dart

@@ -67,11 +67,7 @@ class SpreadElement extends Expression with ControlFlowElement {
   /// during the desugaring.
   DartType? elementType;
 
-  SpreadElement(this.expression, {required this.isNullAware})
+  SpreadElement(this.expression, {required this.isNullAware}) {
-      // ignore: unnecessary_null_comparison
-      : assert(expression != null),
-        // ignore: unnecessary_null_comparison
-        assert(isNullAware != null) {
     expression.parent = this;
   }
 
@@ -82,20 +78,14 @@ class SpreadElement extends Expression with ControlFlowElement {
 
   @override
   void transformChildren(Transformer v) {
-    // ignore: unnecessary_null_comparison
+    expression = v.transform(expression);
-    if (expression != null) {
+    expression.parent = this;
-      expression = v.transform(expression);
-      expression.parent = this;
-    }
   }
 
   @override
   void transformOrRemoveChildren(RemovingTransformer v) {
-    // ignore: unnecessary_null_comparison
+    expression = v.transform(expression);
-    if (expression != null) {
+    expression.parent = this;
-      expression = v.transform(expression);
-      expression.parent = this;
-    }
   }
 
   @override
@@ -126,11 +116,7 @@ class IfElement extends Expression with ControlFlowElement {
   Expression then;
   Expression? otherwise;
 
-  IfElement(this.condition, this.then, this.otherwise)
+  IfElement(this.condition, this.then, this.otherwise) {
-      // ignore: unnecessary_null_comparison
-      : assert(condition != null),
-        // ignore: unnecessary_null_comparison
-        assert(then != null) {
     condition.parent = this;
     then.parent = this;
     otherwise?.parent = this;
@@ -145,16 +131,10 @@ class IfElement extends Expression with ControlFlowElement {
 
   @override
   void transformChildren(Transformer v) {
-    // ignore: unnecessary_null_comparison
+    condition = v.transform(condition);
-    if (condition != null) {
+    condition.parent = this;
-      condition = v.transform(condition);
+    then = v.transform(then);
-      condition.parent = this;
+    then.parent = this;
-    }
-    // ignore: unnecessary_null_comparison
-    if (then != null) {
-      then = v.transform(then);
-      then.parent = this;
-    }
     if (otherwise != null) {
       otherwise = v.transform(otherwise!);
       otherwise?.parent = this;
@@ -163,16 +143,10 @@ class IfElement extends Expression with ControlFlowElement {
 
   @override
   void transformOrRemoveChildren(RemovingTransformer v) {
-    // ignore: unnecessary_null_comparison
+    condition = v.transform(condition);
-    if (condition != null) {
+    condition.parent = this;
-      condition = v.transform(condition);
+    then = v.transform(then);
-      condition.parent = this;
+    then.parent = this;
-    }
-    // ignore: unnecessary_null_comparison
-    if (then != null) {
-      then = v.transform(then);
-      then.parent = this;
-    }
     if (otherwise != null) {
       otherwise = v.transformOrRemoveExpression(otherwise!);
       otherwise?.parent = this;
@@ -229,9 +203,7 @@ class ForElement extends Expression with ControlFlowElement {
   final List<Expression> updates; // May be empty, but not null.
   Expression body;
 
-  ForElement(this.variables, this.condition, this.updates, this.body)
+  ForElement(this.variables, this.condition, this.updates, this.body) {
-      // ignore: unnecessary_null_comparison
-      : assert(body != null) {
     setParents(variables, this);
     condition?.parent = this;
     setParents(updates, this);
@@ -254,11 +226,8 @@ class ForElement extends Expression with ControlFlowElement {
       condition?.parent = this;
     }
     v.transformList(updates, this);
-    // ignore: unnecessary_null_comparison
+    body = v.transform(body);
-    if (body != null) {
+    body.parent = this;
-      body = v.transform(body);
-      body.parent = this;
-    }
   }
 
   @override
@@ -269,11 +238,8 @@ class ForElement extends Expression with ControlFlowElement {
       condition?.parent = this;
     }
     v.transformExpressionList(updates, this);
-    // ignore: unnecessary_null_comparison
+    body = v.transform(body);
-    if (body != null) {
+    body.parent = this;
-      body = v.transform(body);
-      body.parent = this;
-    }
   }
 
   @override
@@ -331,13 +297,7 @@ class ForInElement extends Expression with ControlFlowElement {
 
   ForInElement(this.variable, this.iterable, this.syntheticAssignment,
       this.expressionEffects, this.body, this.problem,
-      {this.isAsync = false})
+      {this.isAsync = false}) {
-      // ignore: unnecessary_null_comparison
-      : assert(variable != null),
-        // ignore: unnecessary_null_comparison
-        assert(iterable != null),
-        // ignore: unnecessary_null_comparison
-        assert(body != null) {
     variable.parent = this;
     iterable.parent = this;
     syntheticAssignment?.parent = this;
@@ -363,16 +323,10 @@ class ForInElement extends Expression with ControlFlowElement {
 
   @override
   void transformChildren(Transformer v) {
-    // ignore: unnecessary_null_comparison
+    variable = v.transform(variable);
-    if (variable != null) {
+    variable.parent = this;
-      variable = v.transform(variable);
+    iterable = v.transform(iterable);
-      variable.parent = this;
+    iterable.parent = this;
-    }
-    // ignore: unnecessary_null_comparison
-    if (iterable != null) {
-      iterable = v.transform(iterable);
-      iterable.parent = this;
-    }
     if (syntheticAssignment != null) {
       syntheticAssignment = v.transform(syntheticAssignment!);
       syntheticAssignment?.parent = this;
@@ -381,11 +335,8 @@ class ForInElement extends Expression with ControlFlowElement {
       expressionEffects = v.transform(expressionEffects!);
       expressionEffects?.parent = this;
     }
-    // ignore: unnecessary_null_comparison
+    body = v.transform(body);
-    if (body != null) {
+    body.parent = this;
-      body = v.transform(body);
-      body.parent = this;
-    }
     if (problem != null) {
       problem = v.transform(problem!);
       problem?.parent = this;
@@ -394,16 +345,10 @@ class ForInElement extends Expression with ControlFlowElement {
 
   @override
   void transformOrRemoveChildren(RemovingTransformer v) {
-    // ignore: unnecessary_null_comparison
+    variable = v.transform(variable);
-    if (variable != null) {
+    variable.parent = this;
-      variable = v.transform(variable);
+    iterable = v.transform(iterable);
-      variable.parent = this;
+    iterable.parent = this;
-    }
-    // ignore: unnecessary_null_comparison
-    if (iterable != null) {
-      iterable = v.transform(iterable);
-      iterable.parent = this;
-    }
     if (syntheticAssignment != null) {
       syntheticAssignment = v.transformOrRemoveExpression(syntheticAssignment!);
       syntheticAssignment?.parent = this;
@@ -412,11 +357,8 @@ class ForInElement extends Expression with ControlFlowElement {
       expressionEffects = v.transformOrRemoveStatement(expressionEffects!);
       expressionEffects?.parent = this;
     }
-    // ignore: unnecessary_null_comparison
+    body = v.transform(body);
-    if (body != null) {
+    body.parent = this;
-      body = v.transform(body);
-      body.parent = this;
-    }
     if (problem != null) {
       problem = v.transformOrRemoveExpression(problem!);
       problem?.parent = this;
@@ -493,11 +435,7 @@ class SpreadMapEntry extends TreeNode with ControlFlowMapEntry {
   /// during the desugaring.
   DartType? entryType;
 
-  SpreadMapEntry(this.expression, {required this.isNullAware})
+  SpreadMapEntry(this.expression, {required this.isNullAware}) {
-      // ignore: unnecessary_null_comparison
-      : assert(expression != null),
-        // ignore: unnecessary_null_comparison
-        assert(isNullAware != null) {
     expression.parent = this;
   }
 
@@ -508,20 +446,14 @@ class SpreadMapEntry extends TreeNode with ControlFlowMapEntry {
 
   @override
   void transformChildren(Transformer v) {
-    // ignore: unnecessary_null_comparison
+    expression = v.transform(expression);
-    if (expression != null) {
+    expression.parent = this;
-      expression = v.transform(expression);
-      expression.parent = this;
-    }
   }
 
   @override
   void transformOrRemoveChildren(RemovingTransformer v) {
-    // ignore: unnecessary_null_comparison
+    expression = v.transform(expression);
-    if (expression != null) {
+    expression.parent = this;
-      expression = v.transform(expression);
-      expression.parent = this;
-    }
   }
 
   @override
@@ -542,11 +474,7 @@ class IfMapEntry extends TreeNode with ControlFlowMapEntry {
   MapLiteralEntry then;
   MapLiteralEntry? otherwise;
 
-  IfMapEntry(this.condition, this.then, this.otherwise)
+  IfMapEntry(this.condition, this.then, this.otherwise) {
-      // ignore: unnecessary_null_comparison
-      : assert(condition != null),
-        // ignore: unnecessary_null_comparison
-        assert(then != null) {
     condition.parent = this;
     then.parent = this;
     otherwise?.parent = this;
@@ -561,16 +489,10 @@ class IfMapEntry extends TreeNode with ControlFlowMapEntry {
 
   @override
   void transformChildren(Transformer v) {
-    // ignore: unnecessary_null_comparison
+    condition = v.transform(condition);
-    if (condition != null) {
+    condition.parent = this;
-      condition = v.transform(condition);
+    then = v.transform(then);
-      condition.parent = this;
+    then.parent = this;
-    }
-    // ignore: unnecessary_null_comparison
-    if (then != null) {
-      then = v.transform(then);
-      then.parent = this;
-    }
     if (otherwise != null) {
       otherwise = v.transform(otherwise!);
       otherwise?.parent = this;
@@ -579,16 +501,10 @@ class IfMapEntry extends TreeNode with ControlFlowMapEntry {
 
   @override
   void transformOrRemoveChildren(RemovingTransformer v) {
-    // ignore: unnecessary_null_comparison
+    condition = v.transform(condition);
-    if (condition != null) {
+    condition.parent = this;
-      condition = v.transform(condition);
+    then = v.transform(then);
-      condition.parent = this;
+    then.parent = this;
-    }
-    // ignore: unnecessary_null_comparison
-    if (then != null) {
-      then = v.transform(then);
-      then.parent = this;
-    }
     if (otherwise != null) {
       otherwise = v.transformOrRemove(otherwise!, dummyMapLiteralEntry);
       otherwise?.parent = this;
@@ -620,9 +536,7 @@ class ForMapEntry extends TreeNode with ControlFlowMapEntry {
   final List<Expression> updates; // May be empty, but not null.
   MapLiteralEntry body;
 
-  ForMapEntry(this.variables, this.condition, this.updates, this.body)
+  ForMapEntry(this.variables, this.condition, this.updates, this.body) {
-      // ignore: unnecessary_null_comparison
-      : assert(body != null) {
     setParents(variables, this);
     condition?.parent = this;
     setParents(updates, this);
@@ -645,11 +559,8 @@ class ForMapEntry extends TreeNode with ControlFlowMapEntry {
       condition?.parent = this;
     }
     v.transformList(updates, this);
-    // ignore: unnecessary_null_comparison
+    body = v.transform(body);
-    if (body != null) {
+    body.parent = this;
-      body = v.transform(body);
-      body.parent = this;
-    }
   }
 
   @override
@@ -660,11 +571,8 @@ class ForMapEntry extends TreeNode with ControlFlowMapEntry {
       condition?.parent = this;
     }
     v.transformExpressionList(updates, this);
-    // ignore: unnecessary_null_comparison
+    body = v.transform(body);
-    if (body != null) {
+    body.parent = this;
-      body = v.transform(body);
-      body.parent = this;
-    }
   }
 
   @override
@@ -705,13 +613,7 @@ class ForInMapEntry extends TreeNode with ControlFlowMapEntry {
 
   ForInMapEntry(this.variable, this.iterable, this.syntheticAssignment,
       this.expressionEffects, this.body, this.problem,
-      {required this.isAsync})
+      {required this.isAsync}) {
-      // ignore: unnecessary_null_comparison
-      : assert(iterable != null),
-        // ignore: unnecessary_null_comparison
-        assert(body != null),
-        // ignore: unnecessary_null_comparison
-        assert(isAsync != null) {
     variable.parent = this;
     iterable.parent = this;
     syntheticAssignment?.parent = this;
@@ -737,16 +639,10 @@ class ForInMapEntry extends TreeNode with ControlFlowMapEntry {
 
   @override
   void transformChildren(Transformer v) {
-    // ignore: unnecessary_null_comparison
+    variable = v.transform(variable);
-    if (variable != null) {
+    variable.parent = this;
-      variable = v.transform(variable);
+    iterable = v.transform(iterable);
-      variable.parent = this;
+    iterable.parent = this;
-    }
-    // ignore: unnecessary_null_comparison
-    if (iterable != null) {
-      iterable = v.transform(iterable);
-      iterable.parent = this;
-    }
     if (syntheticAssignment != null) {
       syntheticAssignment = v.transform(syntheticAssignment!);
       syntheticAssignment?.parent = this;
@@ -755,11 +651,8 @@ class ForInMapEntry extends TreeNode with ControlFlowMapEntry {
       expressionEffects = v.transform(expressionEffects!);
       expressionEffects?.parent = this;
     }
-    // ignore: unnecessary_null_comparison
+    body = v.transform(body);
-    if (body != null) {
+    body.parent = this;
-      body = v.transform(body);
-      body.parent = this;
-    }
     if (problem != null) {
       problem = v.transform(problem!);
       problem?.parent = this;
@@ -768,16 +661,10 @@ class ForInMapEntry extends TreeNode with ControlFlowMapEntry {
 
   @override
   void transformOrRemoveChildren(RemovingTransformer v) {
-    // ignore: unnecessary_null_comparison
+    variable = v.transform(variable);
-    if (variable != null) {
+    variable.parent = this;
-      variable = v.transform(variable);
+    iterable = v.transform(iterable);
-      variable.parent = this;
+    iterable.parent = this;
-    }
-    // ignore: unnecessary_null_comparison
-    if (iterable != null) {
-      iterable = v.transform(iterable);
-      iterable.parent = this;
-    }
     if (syntheticAssignment != null) {
       syntheticAssignment = v.transformOrRemoveExpression(syntheticAssignment!);
       syntheticAssignment?.parent = this;
@@ -786,11 +673,8 @@ class ForInMapEntry extends TreeNode with ControlFlowMapEntry {
       expressionEffects = v.transformOrRemoveStatement(expressionEffects!);
       expressionEffects?.parent = this;
     }
-    // ignore: unnecessary_null_comparison
+    body = v.transform(body);
-    if (body != null) {
+    body.parent = this;
-      body = v.transform(body);
-      body.parent = this;
-    }
     if (problem != null) {
       problem = v.transformOrRemoveExpression(problem!);
       problem?.parent = this;

pkg/front_end/lib/src/fasta/kernel/combined_member_signature.dart

@@ -104,9 +104,7 @@ abstract class CombinedMemberSignatureBase<T> {
   /// Creates a [CombinedClassMemberSignature] whose canonical member is already
   /// defined.
   CombinedMemberSignatureBase.internal(
-      this.classBuilder, this._canonicalMemberIndex, this.forSetter)
+      this.classBuilder, this._canonicalMemberIndex, this.forSetter);
-      // ignore: unnecessary_null_comparison
-      : assert(forSetter != null);
 
   /// Creates a [CombinedClassMemberSignature] for [members] inherited into
   /// [classBuilder].
@@ -115,8 +113,6 @@ abstract class CombinedMemberSignatureBase<T> {
   /// compute the most specific member type. Otherwise covariance of the getter
   /// types or function types is used.
   CombinedMemberSignatureBase(this.classBuilder, {required this.forSetter}) {
-    // ignore: unnecessary_null_comparison
-    assert(forSetter != null);
     int? bestSoFarIndex;
     if (members.length == 1) {
       bestSoFarIndex = 0;
@@ -292,9 +288,6 @@ abstract class CombinedMemberSignatureBase<T> {
     DartType? candidateType = _memberTypes![index];
     if (candidateType == null) {
       Member target = _getMember(index);
-      // ignore: unnecessary_null_comparison
-      assert(target != null,
-          "No member computed for index ${index} in ${members}");
       candidateType = _computeMemberType(thisType, target);
       if (!classBuilder.libraryBuilder.isNonNullableByDefault) {
         DartType? legacyErasure;
@@ -526,8 +519,6 @@ abstract class CombinedMemberSignatureBase<T> {
   /// [type].
   Procedure _createGetterMemberSignature(Member member, DartType type,
       {required bool copyLocation}) {
-    // ignore: unnecessary_null_comparison
-    assert(copyLocation != null);
     Class enclosingClass = classBuilder.cls;
     Reference? reference =
         classBuilder.referencesFromIndexed?.lookupGetterReference(member.name);
@@ -570,12 +561,6 @@ abstract class CombinedMemberSignatureBase<T> {
       required bool isCovariantByClass,
       VariableDeclaration? parameter,
       required bool copyLocation}) {
-    // ignore: unnecessary_null_comparison
-    assert(isCovariantByDeclaration != null);
-    // ignore: unnecessary_null_comparison
-    assert(isCovariantByClass != null);
-    // ignore: unnecessary_null_comparison
-    assert(copyLocation != null);
     Class enclosingClass = classBuilder.cls;
     Reference? reference =
         classBuilder.referencesFromIndexed?.lookupSetterReference(member.name);
@@ -620,8 +605,6 @@ abstract class CombinedMemberSignatureBase<T> {
   Procedure _createMethodSignature(
       Procedure procedure, FunctionType functionType,
       {required bool copyLocation}) {
-    // ignore: unnecessary_null_comparison
-    assert(copyLocation != null);
     Class enclosingClass = classBuilder.cls;
     Reference? reference = classBuilder.referencesFromIndexed
         ?.lookupGetterReference(procedure.name);
@@ -778,21 +761,13 @@ class CombinedClassMemberSignature
   @override
   Member _getMember(int index) {
     ClassMember candidate = members[index];
-    Member target = candidate.getMember(membersBuilder);
+    return candidate.getMember(membersBuilder);
-    // ignore: unnecessary_null_comparison
-    assert(target != null,
-        "No member computed for ${candidate} (${candidate.runtimeType})");
-    return target;
   }
 
   @override
   Covariance _getMemberCovariance(int index) {
     ClassMember candidate = members[index];
-    Covariance covariance = candidate.getCovariance(membersBuilder);
+    return candidate.getCovariance(membersBuilder);
-    // ignore: unnecessary_null_comparison
-    assert(covariance != null,
-        "No covariance computed for ${candidate} (${candidate.runtimeType})");
-    return covariance;
   }
 }
 

pkg/front_end/lib/src/fasta/kernel/constant_evaluator.dart

@@ -64,18 +64,6 @@ Component transformComponent(
     CoreTypes? coreTypes,
     ClassHierarchy? hierarchy,
     ExhaustivenessDataForTesting? exhaustivenessDataForTesting}) {
-  // ignore: unnecessary_null_comparison
-  assert(evaluateAnnotations != null);
-  // ignore: unnecessary_null_comparison
-  assert(desugarSets != null);
-  // ignore: unnecessary_null_comparison
-  assert(enableTripleShift != null);
-  // ignore: unnecessary_null_comparison
-  assert(enableConstFunctions != null);
-  // ignore: unnecessary_null_comparison
-  assert(errorOnUnevaluatedConstant != null);
-  // ignore: unnecessary_null_comparison
-  assert(enableConstructorTearOff != null);
   coreTypes ??= new CoreTypes(component);
   hierarchy ??= new ClassHierarchy(component, coreTypes);
 
@@ -106,16 +94,6 @@ ConstantEvaluationData transformLibraries(
     required bool errorOnUnevaluatedConstant,
     required bool enableConstructorTearOff,
     ExhaustivenessDataForTesting? exhaustivenessDataForTesting}) {
-  // ignore: unnecessary_null_comparison
-  assert(evaluateAnnotations != null);
-  // ignore: unnecessary_null_comparison
-  assert(enableTripleShift != null);
-  // ignore: unnecessary_null_comparison
-  assert(enableConstFunctions != null);
-  // ignore: unnecessary_null_comparison
-  assert(errorOnUnevaluatedConstant != null);
-  // ignore: unnecessary_null_comparison
-  assert(enableConstructorTearOff != null);
   final ConstantsTransformer constantsTransformer = new ConstantsTransformer(
       target,
       environmentDefines,
@@ -151,16 +129,6 @@ void transformProcedure(
     required bool enableConstFunctions,
     required bool enableConstructorTearOff,
     required bool errorOnUnevaluatedConstant}) {
-  // ignore: unnecessary_null_comparison
-  assert(evaluateAnnotations != null);
-  // ignore: unnecessary_null_comparison
-  assert(enableTripleShift != null);
-  // ignore: unnecessary_null_comparison
-  assert(enableConstFunctions != null);
-  // ignore: unnecessary_null_comparison
-  assert(errorOnUnevaluatedConstant != null);
-  // ignore: unnecessary_null_comparison
-  assert(enableConstructorTearOff != null);
   final ConstantsTransformer constantsTransformer = new ConstantsTransformer(
       target,
       environmentDefines,
@@ -657,10 +625,7 @@ class ConstantsTransformer extends RemovingTransformer {
   TreeNode visitFunctionDeclaration(
       FunctionDeclaration node, TreeNode? removalSentinel) {
     if (enableConstFunctions) {
-      // ignore: unnecessary_null_comparison
+      node.function = transform(node.function)..parent = node;
-      if (node.function != null) {
-        node.function = transform(node.function)..parent = node;
-      }
       constantEvaluator.env.addVariableValue(
           node.variable, new FunctionValue(node.function, null));
     } else {
@@ -1609,27 +1574,23 @@ class ConstantsTransformer extends RemovingTransformer {
   TreeNode visitSwitchStatement(
       SwitchStatement node, TreeNode? removalSentinel) {
     TreeNode result = super.visitSwitchStatement(node, removalSentinel);
-    Library library = currentLibrary;
+    for (SwitchCase switchCase in node.cases) {
-    // ignore: unnecessary_null_comparison
+      for (Expression caseExpression in switchCase.expressions) {
-    if (library != null) {
+        if (caseExpression is ConstantExpression) {
-      for (SwitchCase switchCase in node.cases) {
+          if (!constantEvaluator.hasPrimitiveEqual(caseExpression.constant,
-        for (Expression caseExpression in switchCase.expressions) {
+              staticTypeContext: staticTypeContext)) {
-          if (caseExpression is ConstantExpression) {
+            constantEvaluator.errorReporter.report(
-            if (!constantEvaluator.hasPrimitiveEqual(caseExpression.constant,
+                constantEvaluator.createLocatedMessage(
-                staticTypeContext: staticTypeContext)) {
+                    caseExpression,
-              constantEvaluator.errorReporter.report(
+                    templateConstEvalCaseImplementsEqual.withArguments(
-                  constantEvaluator.createLocatedMessage(
+                        caseExpression.constant,
-                      caseExpression,
+                        staticTypeContext.nonNullable ==
-                      templateConstEvalCaseImplementsEqual.withArguments(
+                            Nullability.nonNullable)),
-                          caseExpression.constant,
+                null);
-                          staticTypeContext.nonNullable ==
-                              Nullability.nonNullable)),
-                  null);
-            }
-          } else {
-            // If caseExpression is not ConstantExpression, an error is
-            // reported elsewhere.
           }
+        } else {
+          // If caseExpression is not ConstantExpression, an error is
+          // reported elsewhere.
         }
       }
     }
@@ -2871,8 +2832,6 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
       return error;
     }
     assert(_gotError == null);
-    // ignore: unnecessary_null_comparison
-    assert(type != null);
     return canonicalize(new TypeLiteralConstant(type));
   }
 
@@ -2912,8 +2871,6 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
       return error;
     }
     assert(_gotError == null);
-    // ignore: unnecessary_null_comparison
-    assert(type != null);
 
     final ListConstantBuilder builder = new ListConstantBuilder(
         node, convertType(type), this,
@@ -2949,8 +2906,6 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
       return error;
     }
     assert(_gotError == null);
-    // ignore: unnecessary_null_comparison
-    assert(positional != null);
 
     Map<String, Constant>? named = _evaluateNamedArguments(node.named);
     if (named == null) {
@@ -2959,8 +2914,6 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
       return error;
     }
     assert(_gotError == null);
-    // ignore: unnecessary_null_comparison
-    assert(named != null);
 
     if (shouldBeUnevaluated) {
       return unevaluated(
@@ -3003,8 +2956,6 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
       return error;
     }
     assert(_gotError == null);
-    // ignore: unnecessary_null_comparison
-    assert(type != null);
 
     final SetConstantBuilder builder =
         new SetConstantBuilder(node, convertType(type), this);
@@ -3050,8 +3001,6 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
       return error;
     }
     assert(_gotError == null);
-    // ignore: unnecessary_null_comparison
-    assert(keyType != null);
 
     DartType? valueType = _evaluateDartType(node, node.valueType);
     if (valueType == null) {
@@ -3060,8 +3009,6 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
       return error;
     }
     assert(_gotError == null);
-    // ignore: unnecessary_null_comparison
-    assert(valueType != null);
 
     final MapConstantBuilder builder = new MapConstantBuilder(
         node, convertType(keyType), convertType(valueType), this);
@@ -3127,8 +3074,6 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
       return error;
     }
     assert(_gotError == null);
-    // ignore: unnecessary_null_comparison
-    assert(positional != null);
 
     final Map<String, Constant>? named =
         _evaluateNamedArguments(node.arguments.named);
@@ -3138,8 +3083,6 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
       return error;
     }
     assert(_gotError == null);
-    // ignore: unnecessary_null_comparison
-    assert(named != null);
 
     bool isSymbol = klass == coreTypes.internalSymbolClass;
     if (isSymbol && shouldBeUnevaluated) {
@@ -3174,8 +3117,6 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
       return error;
     }
     assert(_gotError == null);
-    // ignore: unnecessary_null_comparison
-    assert(types != null);
 
     final List<DartType> typeArguments = convertTypes(types);
 
@@ -3307,8 +3248,6 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
       'unary-'
     };
 
-    // ignore: unnecessary_null_comparison
-    if (name == null) return false;
     if (name == '') return true;
 
     final List<String> parts = name.split('.');
@@ -3463,8 +3402,6 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
             return error;
           }
           assert(_gotError == null);
-          // ignore: unnecessary_null_comparison
-          assert(types != null);
 
           List<Constant>? positionalArguments =
               _evaluatePositionalArguments(init.arguments.positional);
@@ -3474,8 +3411,6 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
             return error;
           }
           assert(_gotError == null);
-          // ignore: unnecessary_null_comparison
-          assert(positionalArguments != null);
           Map<String, Constant>? namedArguments =
               _evaluateNamedArguments(init.arguments.named);
           if (namedArguments == null) {
@@ -3484,8 +3419,6 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
             return error;
           }
           assert(_gotError == null);
-          // ignore: unnecessary_null_comparison
-          assert(namedArguments != null);
           error = handleConstructorInvocation(
               init.target, types, positionalArguments, namedArguments, caller);
           if (error != null) return error;
@@ -3504,8 +3437,6 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
             return error;
           }
           assert(_gotError == null);
-          // ignore: unnecessary_null_comparison
-          assert(positionalArguments != null);
 
           Map<String, Constant>? namedArguments =
               _evaluateNamedArguments(init.arguments.named);
@@ -3515,8 +3446,6 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
             return error;
           }
           assert(_gotError == null);
-          // ignore: unnecessary_null_comparison
-          assert(namedArguments != null);
 
           error = handleConstructorInvocation(init.target, typeArguments,
               positionalArguments, namedArguments, caller);
@@ -3544,8 +3473,7 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
         instanceBuilder!.unusedArguments.add(_wrap(constant));
       }
 
-      // ignore: unnecessary_null_comparison
+      if (enableConstFunctions) {
-      if (enableConstFunctions && constructor.function != null) {
         AbortConstant? error = executeConstructorBody(constructor);
         if (error != null) return error;
       }
@@ -3643,8 +3571,6 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
       return error;
     }
     assert(_gotError == null);
-    // ignore: unnecessary_null_comparison
-    assert(positionalArguments != null);
 
     if (shouldBeUnevaluated) {
       return unevaluated(
@@ -3688,8 +3614,6 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
       return error;
     }
     assert(_gotError == null);
-    // ignore: unnecessary_null_comparison
-    assert(positionalArguments != null);
 
     if (shouldBeUnevaluated) {
       return unevaluated(
@@ -3733,8 +3657,6 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
     }
 
     final Constant receiver = env.lookupVariable(node.variable)!;
-    // ignore: unnecessary_null_comparison
-    assert(receiver != null);
     if (receiver is AbortConstant) return receiver;
 
     return _evaluateFunctionInvocation(node, receiver, node.arguments);
@@ -3751,8 +3673,6 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
       return error;
     }
     assert(_gotError == null);
-    // ignore: unnecessary_null_comparison
-    assert(positional != null);
 
     // Evaluate type arguments of the function invoked.
     List<DartType>? types = _evaluateTypeArguments(node, arguments);
@@ -3762,8 +3682,6 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
       return error;
     }
     assert(_gotError == null);
-    // ignore: unnecessary_null_comparison
-    assert(types != null);
 
     // Evaluate named arguments of the function invoked.
     final Map<String, Constant>? named =
@@ -3774,8 +3692,6 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
       return error;
     }
     assert(_gotError == null);
-    // ignore: unnecessary_null_comparison
-    assert(named != null);
 
     if (receiver is FunctionValue) {
       return _handleFunctionInvocation(
@@ -4048,8 +3964,6 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
         return error;
       }
       assert(_gotError == null);
-      // ignore: unnecessary_null_comparison
-      assert(typeArguments != null);
 
       // Evaluate named arguments of the method invoked.
       final Map<String, Constant>? namedArguments =
@@ -4060,8 +3974,6 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
         return error;
       }
       assert(_gotError == null);
-      // ignore: unnecessary_null_comparison
-      assert(namedArguments != null);
 
       if (receiver is FunctionValue && name == Name.callName) {
         return _handleFunctionInvocation(receiver.function, typeArguments,
@@ -4616,8 +4528,6 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
       return error;
     }
     assert(_gotError == null);
-    // ignore: unnecessary_null_comparison
-    assert(types != null);
 
     final List<DartType> typeArguments = convertTypes(types);
 
@@ -4629,8 +4539,6 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
       return error;
     }
     assert(_gotError == null);
-    // ignore: unnecessary_null_comparison
-    assert(positional != null);
 
     final Map<String, Constant>? named =
         _evaluateNamedArguments(arguments.named);
@@ -4640,8 +4548,6 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
       return error;
     }
     assert(_gotError == null);
-    // ignore: unnecessary_null_comparison
-    assert(named != null);
 
     if (shouldBeUnevaluated) {
       return unevaluated(
@@ -4815,8 +4721,6 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
       return error;
     }
     assert(_gotError == null);
-    // ignore: unnecessary_null_comparison
-    assert(type != null);
     return ensureIsSubtype(constant, type, node);
   }
 
@@ -4839,12 +4743,8 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
       return error;
     }
     assert(_gotError == null);
-    // ignore: unnecessary_null_comparison
-    assert(type != null);
 
     bool performIs(Constant constant, {required bool strongMode}) {
-      // ignore: unnecessary_null_comparison
-      assert(strongMode != null);
       if (strongMode) {
         return isSubtype(constant, type, SubtypeCheckMode.withNullabilities);
       } else {
@@ -4970,8 +4870,6 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
           return error;
         }
         assert(_gotError == null);
-        // ignore: unnecessary_null_comparison
-        assert(types != null);
 
         return canonicalize(
             new InstantiationConstant(constant, convertTypes(types)));
@@ -5248,8 +5146,6 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
         return null;
       }
       assert(_gotError == null);
-      // ignore: unnecessary_null_comparison
-      assert(type != null);
       result[i] = type;
     }
     return result;

pkg/front_end/lib/src/fasta/kernel/expression_generator.dart

@@ -223,8 +223,6 @@ abstract class Generator {
 
   Expression_Generator buildEqualsOperation(Token token, Expression right,
       {required bool isNot}) {
-    // ignore: unnecessary_null_comparison
-    assert(isNot != null);
     return _forest.createEquals(offsetForToken(token), buildSimpleRead(), right,
         isNot: isNot);
   }
@@ -401,8 +399,6 @@ class VariableUseGenerator extends Generator {
   @override
   Generator buildIndexedAccess(Expression index, Token token,
       {required bool isNullAware}) {
-    // ignore: unnecessary_null_comparison
-    assert(isNullAware != null);
     return new IndexedAccessGenerator(_helper, token, buildSimpleRead(), index,
         isNullAware: isNullAware);
   }
@@ -525,8 +521,6 @@ class PropertyAccessGenerator extends Generator {
   @override
   Generator buildIndexedAccess(Expression index, Token token,
       {required bool isNullAware}) {
-    // ignore: unnecessary_null_comparison
-    assert(isNullAware != null);
     return new IndexedAccessGenerator(_helper, token, buildSimpleRead(), index,
         isNullAware: isNullAware);
   }
@@ -687,8 +681,6 @@ class ThisPropertyAccessGenerator extends Generator {
   @override
   Generator buildIndexedAccess(Expression index, Token token,
       {required bool isNullAware}) {
-    // ignore: unnecessary_null_comparison
-    assert(isNullAware != null);
     return new IndexedAccessGenerator(_helper, token, buildSimpleRead(), index,
         isNullAware: isNullAware);
   }
@@ -794,8 +786,6 @@ class NullAwarePropertyAccessGenerator extends Generator {
   @override
   Generator buildIndexedAccess(Expression index, Token token,
       {required bool isNullAware}) {
-    // ignore: unnecessary_null_comparison
-    assert(isNullAware != null);
     return new IndexedAccessGenerator(_helper, token, buildSimpleRead(), index,
         isNullAware: isNullAware);
   }
@@ -919,8 +909,6 @@ class SuperPropertyAccessGenerator extends Generator {
   @override
   Generator buildIndexedAccess(Expression index, Token token,
       {required bool isNullAware}) {
-    // ignore: unnecessary_null_comparison
-    assert(isNullAware != null);
     return new IndexedAccessGenerator(_helper, token, buildSimpleRead(), index,
         isNullAware: isNullAware);
   }
@@ -946,9 +934,7 @@ class IndexedAccessGenerator extends Generator {
   IndexedAccessGenerator(
       ExpressionGeneratorHelper helper, Token token, this.receiver, this.index,
       {required this.isNullAware})
-      // ignore: unnecessary_null_comparison
+      : super(helper, token);
-      : assert(isNullAware != null),
-        super(helper, token);
 
   @override
   String get _plainNameForRead => "[]";
@@ -1072,8 +1058,6 @@ class IndexedAccessGenerator extends Generator {
   @override
   Generator buildIndexedAccess(Expression index, Token token,
       {required bool isNullAware}) {
-    // ignore: unnecessary_null_comparison
-    assert(isNullAware != null);
     return new IndexedAccessGenerator(_helper, token, buildSimpleRead(), index,
         isNullAware: isNullAware);
   }
@@ -1091,8 +1075,6 @@ class IndexedAccessGenerator extends Generator {
   static Generator make(ExpressionGeneratorHelper helper, Token token,
       Expression receiver, Expression index,
       {required bool isNullAware}) {
-    // ignore: unnecessary_null_comparison
-    assert(isNullAware != null);
     if (helper.forest.isThisExpression(receiver)) {
       return new ThisIndexedAccessGenerator(helper, token, index,
           thisOffset: receiver.fileOffset, isNullAware: isNullAware);
@@ -1195,8 +1177,6 @@ class ThisIndexedAccessGenerator extends Generator {
   @override
   Generator buildIndexedAccess(Expression index, Token token,
       {required bool isNullAware}) {
-    // ignore: unnecessary_null_comparison
-    assert(isNullAware != null);
     return new IndexedAccessGenerator(_helper, token, buildSimpleRead(), index,
         isNullAware: isNullAware);
   }
@@ -1321,8 +1301,6 @@ class SuperIndexedAccessGenerator extends Generator {
   @override
   Generator buildIndexedAccess(Expression index, Token token,
       {required bool isNullAware}) {
-    // ignore: unnecessary_null_comparison
-    assert(isNullAware != null);
     return new IndexedAccessGenerator(_helper, token, buildSimpleRead(), index,
         isNullAware: isNullAware);
   }
@@ -1401,9 +1379,7 @@ class StaticAccessGenerator extends Generator {
   StaticAccessGenerator(ExpressionGeneratorHelper helper, Token token,
       this.targetName, this.parentBuilder, this.readTarget, this.writeTarget,
       {this.typeOffset, this.isNullAware = false})
-      // ignore: unnecessary_null_comparison
+      : assert(readTarget != null || writeTarget != null),
-      : assert(targetName != null),
-        assert(readTarget != null || writeTarget != null),
         assert(parentBuilder is DeclarationBuilder ||
             parentBuilder is LibraryBuilder),
         super(helper, token);
@@ -1563,8 +1539,6 @@ class StaticAccessGenerator extends Generator {
   @override
   Generator buildIndexedAccess(Expression index, Token token,
       {required bool isNullAware}) {
-    // ignore: unnecessary_null_comparison
-    assert(isNullAware != null);
     return new IndexedAccessGenerator(_helper, token, buildSimpleRead(), index,
         isNullAware: isNullAware);
   }
@@ -1647,12 +1621,8 @@ class ExtensionInstanceAccessGenerator extends Generator {
       this.writeTarget,
       this.extensionThis,
       this.extensionTypeParameters)
-      // ignore: unnecessary_null_comparison
+      : assert(
-      : assert(targetName != null),
-        assert(
             readTarget != null || invokeTarget != null || writeTarget != null),
-        // ignore: unnecessary_null_comparison
-        assert(extensionThis != null),
         super(helper, token);
 
   factory ExtensionInstanceAccessGenerator.fromBuilder(
@@ -1850,8 +1820,6 @@ class ExtensionInstanceAccessGenerator extends Generator {
   @override
   Generator buildIndexedAccess(Expression index, Token token,
       {required bool isNullAware}) {
-    // ignore: unnecessary_null_comparison
-    assert(isNullAware != null);
     return new IndexedAccessGenerator(_helper, token, buildSimpleRead(), index,
         isNullAware: isNullAware);
   }
@@ -1948,14 +1916,8 @@ class ExplicitExtensionInstanceAccessGenerator extends Generator {
       this.explicitTypeArguments,
       this.extensionTypeParameterCount,
       {required this.isNullAware})
-      // ignore: unnecessary_null_comparison
+      : assert(
-      : assert(targetName != null),
-        assert(
             readTarget != null || invokeTarget != null || writeTarget != null),
-        // ignore: unnecessary_null_comparison
-        assert(receiver != null),
-        // ignore: unnecessary_null_comparison
-        assert(isNullAware != null),
         super(helper, token);
 
   factory ExplicitExtensionInstanceAccessGenerator.fromBuilder(
@@ -2276,8 +2238,6 @@ class ExplicitExtensionInstanceAccessGenerator extends Generator {
   @override
   Generator buildIndexedAccess(Expression index, Token token,
       {required bool isNullAware}) {
-    // ignore: unnecessary_null_comparison
-    assert(isNullAware != null);
     return new IndexedAccessGenerator(_helper, token, buildSimpleRead(), index,
         isNullAware: isNullAware);
   }
@@ -2339,10 +2299,6 @@ class ExplicitExtensionIndexedAccessGenerator extends Generator {
       this.extensionTypeParameterCount,
       {required this.isNullAware})
       : assert(readTarget != null || writeTarget != null),
-        // ignore: unnecessary_null_comparison
-        assert(receiver != null),
-        // ignore: unnecessary_null_comparison
-        assert(isNullAware != null),
         super(helper, token);
 
   factory ExplicitExtensionIndexedAccessGenerator.fromBuilder(
@@ -2357,8 +2313,6 @@ class ExplicitExtensionIndexedAccessGenerator extends Generator {
       List<DartType>? explicitTypeArguments,
       int extensionTypeParameterCount,
       {required bool isNullAware}) {
-    // ignore: unnecessary_null_comparison
-    assert(isNullAware != null);
     Procedure? readTarget;
     if (getterBuilder != null) {
       if (getterBuilder is AccessErrorBuilder) {
@@ -2561,8 +2515,6 @@ class ExplicitExtensionIndexedAccessGenerator extends Generator {
   @override
   Generator buildIndexedAccess(Expression index, Token token,
       {required bool isNullAware}) {
-    // ignore: unnecessary_null_comparison
-    assert(isNullAware != null);
     return new IndexedAccessGenerator(_helper, token, buildSimpleRead(), index,
         isNullAware: isNullAware);
   }
@@ -2747,8 +2699,6 @@ class ExplicitExtensionAccessGenerator extends Generator {
   @override
   Generator buildIndexedAccess(Expression index, Token token,
       {required bool isNullAware}) {
-    // ignore: unnecessary_null_comparison
-    assert(isNullAware != null);
     Builder? getter = extensionBuilder.lookupLocalMemberByName(indexGetName);
     Builder? setter = extensionBuilder.lookupLocalMemberByName(indexSetName);
     if (getter == null && setter == null) {
@@ -2852,8 +2802,6 @@ class LoadLibraryGenerator extends Generator {
   @override
   Generator buildIndexedAccess(Expression index, Token token,
       {required bool isNullAware}) {
-    // ignore: unnecessary_null_comparison
-    assert(isNullAware != null);
     return new IndexedAccessGenerator(_helper, token, buildSimpleRead(), index,
         isNullAware: isNullAware);
   }
@@ -3018,8 +2966,6 @@ class DeferredAccessGenerator extends Generator {
   @override
   Generator buildIndexedAccess(Expression index, Token token,
       {required bool isNullAware}) {
-    // ignore: unnecessary_null_comparison
-    assert(isNullAware != null);
     return new IndexedAccessGenerator(_helper, token, buildSimpleRead(), index,
         isNullAware: isNullAware);
   }
@@ -3547,15 +3493,11 @@ abstract class AbstractReadOnlyAccessGenerator extends Generator {
   Expression _makeInvalidWrite(Expression value) {
     switch (kind) {
       case ReadOnlyAccessKind.ConstVariable:
-        // ignore: unnecessary_null_comparison
-        assert(targetName != null);
         return _helper.buildProblem(
             templateCannotAssignToConstVariable.withArguments(targetName),
             fileOffset,
             lengthForToken(token));
       case ReadOnlyAccessKind.FinalVariable:
-        // ignore: unnecessary_null_comparison
-        assert(targetName != null);
         return _helper.buildProblem(
             templateCannotAssignToFinalVariable.withArguments(targetName),
             fileOffset,
@@ -3622,8 +3564,6 @@ abstract class AbstractReadOnlyAccessGenerator extends Generator {
   @override
   Generator buildIndexedAccess(Expression index, Token token,
       {required bool isNullAware}) {
-    // ignore: unnecessary_null_comparison
-    assert(isNullAware != null);
     // TODO(johnniwinther): The read-only quality of the variable should be
     // passed on to the generator.
     return new IndexedAccessGenerator(_helper, token, _createRead(), index,
@@ -3757,8 +3697,6 @@ abstract class ErroneousExpressionGenerator extends Generator {
   @override
   Generator buildIndexedAccess(Expression index, Token token,
       {required bool isNullAware}) {
-    // ignore: unnecessary_null_comparison
-    assert(isNullAware != null);
     return new IndexedAccessGenerator(_helper, token, buildSimpleRead(), index,
         isNullAware: isNullAware);
   }
@@ -3846,8 +3784,6 @@ class UnresolvedNameGenerator extends ErroneousExpressionGenerator {
   @override
   Generator buildIndexedAccess(Expression index, Token token,
       {required bool isNullAware}) {
-    // ignore: unnecessary_null_comparison
-    assert(isNullAware != null);
     return new IndexedAccessGenerator(_helper, token, buildSimpleRead(), index,
         isNullAware: isNullAware);
   }
@@ -3918,8 +3854,6 @@ abstract class ContextAwareGenerator extends Generator {
   @override
   Generator buildIndexedAccess(Expression index, Token token,
       {required bool isNullAware}) {
-    // ignore: unnecessary_null_comparison
-    assert(isNullAware != null);
     return new IndexedAccessGenerator(_helper, token, buildSimpleRead(), index,
         isNullAware: isNullAware);
   }
@@ -4155,8 +4089,6 @@ class PrefixUseGenerator extends Generator {
   @override
   Generator buildIndexedAccess(Expression index, Token token,
       {required bool isNullAware}) {
-    // ignore: unnecessary_null_comparison
-    assert(isNullAware != null);
     return new IndexedAccessGenerator(_helper, token, buildSimpleRead(), index,
         isNullAware: isNullAware);
   }
@@ -4249,8 +4181,6 @@ class UnexpectedQualifiedUseGenerator extends Generator {
   @override
   Generator buildIndexedAccess(Expression index, Token token,
       {required bool isNullAware}) {
-    // ignore: unnecessary_null_comparison
-    assert(isNullAware != null);
     return new IndexedAccessGenerator(_helper, token, buildSimpleRead(), index,
         isNullAware: isNullAware);
   }
@@ -4379,8 +4309,6 @@ class ParserErrorGenerator extends Generator {
   @override
   Generator buildIndexedAccess(Expression index, Token token,
       {required bool isNullAware}) {
-    // ignore: unnecessary_null_comparison
-    assert(isNullAware != null);
     return new IndexedAccessGenerator(_helper, token, buildSimpleRead(), index,
         isNullAware: isNullAware);
   }
@@ -4572,8 +4500,6 @@ class ThisAccessGenerator extends Generator {
   @override
   Expression_Generator buildEqualsOperation(Token token, Expression right,
       {required bool isNot}) {
-    // ignore: unnecessary_null_comparison
-    assert(isNot != null);
     if (isSuper) {
       int offset = offsetForToken(token);
       Expression result = _helper.buildSuperInvocation(equalsName,
@@ -4669,8 +4595,6 @@ class ThisAccessGenerator extends Generator {
   @override
   Generator buildIndexedAccess(Expression index, Token token,
       {required bool isNullAware}) {
-    // ignore: unnecessary_null_comparison
-    assert(isNullAware != null);
     if (isSuper) {
       return new SuperIndexedAccessGenerator(
           _helper,
@@ -4909,10 +4833,7 @@ class InvocationSelector extends Selector {
   InvocationSelector(ExpressionGeneratorHelper helper, Token token, this.name,
       this.typeArguments, this.arguments,
       {this.isPotentiallyConstant = false, this.isTypeArgumentsInForest = true})
-      : super(helper, token) {
+      : super(helper, token);
-    // ignore: unnecessary_null_comparison
-    assert(arguments != null);
-  }
 
   @override
   String get _debugName => 'InvocationSelector';

pkg/front_end/lib/src/fasta/kernel/forest.dart

@@ -32,8 +32,6 @@ class Forest {
       List<NamedExpression>? named,
       bool hasExplicitTypeArguments = true,
       List<Object?>? argumentsOriginalOrder}) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     if (!hasExplicitTypeArguments) {
       ArgumentsImpl arguments = new ArgumentsImpl(positional,
           types: <DartType>[],
@@ -61,8 +59,6 @@ class Forest {
       List<Expression> positionalArguments = const <Expression>[],
       List<NamedExpression> namedArguments = const <NamedExpression>[],
       List<Object?>? argumentsOriginalOrder}) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new ArgumentsImpl.forExtensionMethod(
         extensionTypeParameterCount, typeParameterCount, receiver,
         extensionTypeArguments: extensionTypeArguments,
@@ -75,8 +71,6 @@ class Forest {
   }
 
   ArgumentsImpl createArgumentsEmpty(int fileOffset) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return createArguments(fileOffset, <Expression>[]);
   }
 
@@ -100,30 +94,22 @@ class Forest {
   /// Return a representation of a boolean literal at the given [fileOffset].
   /// The literal has the given [value].
   BoolLiteral createBoolLiteral(int fileOffset, bool value) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new BoolLiteral(value)..fileOffset = fileOffset;
   }
 
   /// Return a representation of a double literal at the given [fileOffset]. The
   /// literal has the given [value].
   DoubleLiteral createDoubleLiteral(int fileOffset, double value) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new DoubleLiteral(value)..fileOffset = fileOffset;
   }
 
   /// Return a representation of an integer literal at the given [fileOffset].
   /// The literal has the given [value].
   IntLiteral createIntLiteral(int fileOffset, int value, [String? literal]) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new IntJudgment(value, literal)..fileOffset = fileOffset;
   }
 
   IntLiteral createIntLiteralLarge(int fileOffset, String literal) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new ShadowLargeIntLiteral(literal, fileOffset);
   }
 
@@ -137,10 +123,6 @@ class Forest {
   ListLiteral createListLiteral(
       int fileOffset, DartType typeArgument, List<Expression> expressions,
       {required bool isConst}) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
-    // ignore: unnecessary_null_comparison
-    assert(isConst != null);
     return new ListLiteral(expressions,
         typeArgument: typeArgument, isConst: isConst)
       ..fileOffset = fileOffset;
@@ -156,10 +138,6 @@ class Forest {
   SetLiteral createSetLiteral(
       int fileOffset, DartType typeArgument, List<Expression> expressions,
       {required bool isConst}) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
-    // ignore: unnecessary_null_comparison
-    assert(isConst != null);
     return new SetLiteral(expressions,
         typeArgument: typeArgument, isConst: isConst)
       ..fileOffset = fileOffset;
@@ -177,10 +155,6 @@ class Forest {
   MapLiteral createMapLiteral(int fileOffset, DartType keyType,
       DartType valueType, List<MapLiteralEntry> entries,
       {required bool isConst}) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
-    // ignore: unnecessary_null_comparison
-    assert(isConst != null);
     return new MapLiteral(entries,
         keyType: keyType, valueType: valueType, isConst: isConst)
       ..fileOffset = fileOffset;
@@ -188,8 +162,6 @@ class Forest {
 
   /// Return a representation of a null literal at the given [fileOffset].
   NullLiteral createNullLiteral(int fileOffset) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new NullLiteral()..fileOffset = fileOffset;
   }
 
@@ -197,22 +169,16 @@ class Forest {
   /// [fileOffset]. The literal has the given [value]. This does not include
   /// either adjacent strings or interpolated strings.
   StringLiteral createStringLiteral(int fileOffset, String value) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new StringLiteral(value)..fileOffset = fileOffset;
   }
 
   /// Return a representation of a symbol literal defined by [value] at the
   /// given [fileOffset].
   SymbolLiteral createSymbolLiteral(int fileOffset, String value) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new SymbolLiteral(value)..fileOffset = fileOffset;
   }
 
   TypeLiteral createTypeLiteral(int fileOffset, DartType type) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new TypeLiteral(type)..fileOffset = fileOffset;
   }
 
@@ -222,32 +188,22 @@ class Forest {
   /// to compute the value.
   MapLiteralEntry createMapEntry(
       int fileOffset, Expression key, Expression value) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new MapLiteralEntry(key, value)..fileOffset = fileOffset;
   }
 
   LoadLibrary createLoadLibrary(
       int fileOffset, LibraryDependency dependency, Arguments? arguments) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new LoadLibraryImpl(dependency, arguments)..fileOffset = fileOffset;
   }
 
   Expression checkLibraryIsLoaded(
       int fileOffset, LibraryDependency dependency) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new CheckLibraryIsLoaded(dependency)..fileOffset = fileOffset;
   }
 
   Expression createAsExpression(
       int fileOffset, Expression expression, DartType type,
       {required bool forNonNullableByDefault, bool forDynamic = false}) {
-    // ignore: unnecessary_null_comparison
-    assert(forNonNullableByDefault != null);
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new AsExpression(expression, type)
       ..fileOffset = fileOffset
       ..isForNonNullableByDefault = forNonNullableByDefault
@@ -256,10 +212,6 @@ class Forest {
 
   Expression createSpreadElement(int fileOffset, Expression expression,
       {required bool isNullAware}) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
-    // ignore: unnecessary_null_comparison
-    assert(isNullAware != null);
     return new SpreadElement(expression, isNullAware: isNullAware)
       ..fileOffset = fileOffset;
   }
@@ -267,8 +219,6 @@ class Forest {
   Expression createIfElement(
       int fileOffset, Expression condition, Expression then,
       [Expression? otherwise]) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new IfElement(condition, then, otherwise)..fileOffset = fileOffset;
   }
 
@@ -278,8 +228,6 @@ class Forest {
       required PatternGuard patternGuard,
       required Expression then,
       Expression? otherwise}) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new IfCaseElement(
         prelude: prelude,
         expression: expression,
@@ -292,8 +240,6 @@ class Forest {
   MapLiteralEntry createIfMapEntry(
       int fileOffset, Expression condition, MapLiteralEntry then,
       [MapLiteralEntry? otherwise]) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new IfMapEntry(condition, then, otherwise)..fileOffset = fileOffset;
   }
 
@@ -303,8 +249,6 @@ class Forest {
       required PatternGuard patternGuard,
       required MapLiteralEntry then,
       MapLiteralEntry? otherwise}) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new IfCaseMapEntry(
         prelude: prelude,
         expression: expression,
@@ -320,8 +264,6 @@ class Forest {
       Expression? condition,
       List<Expression> updates,
       Expression body) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new ForElement(variables, condition, updates, body)
       ..fileOffset = fileOffset;
   }
@@ -333,8 +275,6 @@ class Forest {
       required Expression? condition,
       required List<Expression> updates,
       required Expression body}) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new PatternForElement(
         patternVariableDeclaration: patternVariableDeclaration,
         intermediateVariables: intermediateVariables,
@@ -351,8 +291,6 @@ class Forest {
       Expression? condition,
       List<Expression> updates,
       MapLiteralEntry body) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new ForMapEntry(variables, condition, updates, body)
       ..fileOffset = fileOffset;
   }
@@ -364,8 +302,6 @@ class Forest {
       required Expression? condition,
       required List<Expression> updates,
       required MapLiteralEntry body}) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new PatternForMapEntry(
         patternVariableDeclaration: patternVariableDeclaration,
         intermediateVariables: intermediateVariables,
@@ -385,8 +321,6 @@ class Forest {
       Expression body,
       Expression? problem,
       {bool isAsync = false}) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new ForInElement(variable, iterable, synthesizedAssignment,
         expressionEffects, body, problem,
         isAsync: isAsync)
@@ -402,8 +336,6 @@ class Forest {
       MapLiteralEntry body,
       Expression? problem,
       {bool isAsync = false}) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new ForInMapEntry(variable, iterable, synthesizedAssignment,
         expressionEffects, body, problem,
         isAsync: isAsync)
@@ -414,16 +346,12 @@ class Forest {
   /// initializer list.
   AssertInitializer createAssertInitializer(
       int fileOffset, AssertStatement assertStatement) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new AssertInitializer(assertStatement)..fileOffset = fileOffset;
   }
 
   /// Return a representation of an assert that appears as a statement.
   AssertStatement createAssertStatement(int fileOffset, Expression condition,
       Expression? message, int conditionStartOffset, int conditionEndOffset) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new AssertStatement(condition,
         conditionStartOffset: conditionStartOffset,
         conditionEndOffset: conditionEndOffset,
@@ -432,8 +360,6 @@ class Forest {
   }
 
   Expression createAwaitExpression(int fileOffset, Expression operand) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new AwaitExpression(operand)..fileOffset = fileOffset;
   }
 
@@ -441,8 +367,6 @@ class Forest {
   /// [fileOffset].
   Block createBlock(
       int fileOffset, int fileEndOffset, List<Statement> statements) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     List<Statement>? copy;
     for (int i = 0; i < statements.length; i++) {
       Statement statement = statements[i];
@@ -460,8 +384,6 @@ class Forest {
 
   /// Return a representation of a break statement.
   Statement createBreakStatement(int fileOffset, Object? label) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     // TODO(johnniwinther): Use [label]?
     return new BreakStatementImpl(isContinue: false)
       ..fileOffset = fileOffset
@@ -476,8 +398,6 @@ class Forest {
       VariableDeclaration? stackTraceParameter,
       DartType stackTraceType,
       Statement body) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new Catch(exceptionParameter, body,
         guard: exceptionType, stackTrace: stackTraceParameter)
       ..fileOffset = fileOffset;
@@ -499,8 +419,6 @@ class Forest {
 
   /// Return a representation of a continue statement.
   Statement createContinueStatement(int fileOffset, Object? label) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     // TODO(johnniwinther): Use [label]?
     return new BreakStatementImpl(isContinue: true)..fileOffset = fileOffset;
   }
@@ -508,23 +426,17 @@ class Forest {
   /// Return a representation of a do statement.
   Statement createDoStatement(
       int fileOffset, Statement body, Expression condition) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new DoStatement(body, condition)..fileOffset = fileOffset;
   }
 
   /// Return a representation of an expression statement at the given
   /// [fileOffset] containing the [expression].
   Statement createExpressionStatement(int fileOffset, Expression expression) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new ExpressionStatement(expression)..fileOffset = fileOffset;
   }
 
   /// Return a representation of an empty statement  at the given [fileOffset].
   Statement createEmptyStatement(int fileOffset) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new EmptyStatement()..fileOffset = fileOffset;
   }
 
@@ -535,8 +447,6 @@ class Forest {
       Expression? condition,
       List<Expression> updaters,
       Statement body) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new ForStatement(variables ?? [], condition, updaters, body)
       ..fileOffset = fileOffset;
   }
@@ -544,8 +454,6 @@ class Forest {
   /// Return a representation of an `if` statement.
   Statement createIfStatement(int fileOffset, Expression condition,
       Statement thenStatement, Statement? elseStatement) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new IfStatement(condition, thenStatement, elseStatement)
       ..fileOffset = fileOffset;
   }
@@ -553,8 +461,6 @@ class Forest {
   /// Return a representation of a `switch` statement.
   Statement createSwitchStatement(
       int fileOffset, Expression expression, List<SwitchCase> cases) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new SwitchStatement(expression, cases)..fileOffset = fileOffset;
   }
 
@@ -565,10 +471,6 @@ class Forest {
   Expression createIsExpression(
       int fileOffset, Expression operand, DartType type,
       {required bool forNonNullableByDefault, int? notFileOffset}) {
-    // ignore: unnecessary_null_comparison
-    assert(forNonNullableByDefault != null);
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     Expression result = new IsExpression(operand, type)
       ..fileOffset = fileOffset
       ..isForNonNullableByDefault = forNonNullableByDefault;
@@ -583,8 +485,6 @@ class Forest {
   /// (either `&&` or `||`).
   Expression createLogicalExpression(int fileOffset, Expression leftOperand,
       String operatorString, Expression rightOperand) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     LogicalExpressionOperator operator;
     if (operatorString == '&&') {
       operator = LogicalExpressionOperator.AND;
@@ -600,8 +500,6 @@ class Forest {
   }
 
   Expression createNot(int fileOffset, Expression operand) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new Not(operand)..fileOffset = fileOffset;
   }
 
@@ -609,10 +507,6 @@ class Forest {
   /// rethrow at [rethrowFileOffset] and the statement at [statementFileOffset].
   Statement createRethrowStatement(
       int rethrowFileOffset, int statementFileOffset) {
-    // ignore: unnecessary_null_comparison
-    assert(rethrowFileOffset != null);
-    // ignore: unnecessary_null_comparison
-    assert(statementFileOffset != null);
     return new ExpressionStatement(
         new Rethrow()..fileOffset = rethrowFileOffset)
       ..fileOffset = statementFileOffset;
@@ -621,16 +515,12 @@ class Forest {
   /// Return a representation of a return statement.
   Statement createReturnStatement(int fileOffset, Expression? expression,
       {bool isArrow = true}) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new ReturnStatementImpl(isArrow, expression)
       ..fileOffset = fileOffset;
   }
 
   Expression createStringConcatenation(
       int fileOffset, List<Expression> expressions) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     assert(fileOffset != TreeNode.noOffset);
     return new StringConcatenation(expressions)..fileOffset = fileOffset;
   }
@@ -643,15 +533,11 @@ class Forest {
   }
 
   Expression createThisExpression(int fileOffset) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new ThisExpression()..fileOffset = fileOffset;
   }
 
   /// Return a representation of a throw expression at the given [fileOffset].
   Expression createThrow(int fileOffset, Expression expression) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new Throw(expression)..fileOffset = fileOffset;
   }
 
@@ -659,8 +545,6 @@ class Forest {
 
   Statement createTryStatement(int fileOffset, Statement tryBlock,
       List<Catch>? catchBlocks, Statement? finallyBlock) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new TryStatement(tryBlock, catchBlocks ?? <Catch>[], finallyBlock)
       ..fileOffset = fileOffset;
   }
@@ -692,8 +576,6 @@ class Forest {
   /// consisting of the given [condition] and [body].
   Statement createWhileStatement(
       int fileOffset, Expression condition, Statement body) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new WhileStatement(condition, body)..fileOffset = fileOffset;
   }
 
@@ -702,10 +584,6 @@ class Forest {
   /// statement is a yield* statement.
   Statement createYieldStatement(int fileOffset, Expression expression,
       {required bool isYieldStar}) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
-    // ignore: unnecessary_null_comparison
-    assert(isYieldStar != null);
     return new YieldStatement(expression, isYieldStar: isYieldStar)
       ..fileOffset = fileOffset;
   }
@@ -741,8 +619,6 @@ class Forest {
       bool isCovariantByDeclaration = false,
       bool isLocalFunction = false,
       bool isSynthesized = false}) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new VariableDeclarationImpl(name,
         type: type,
         initializer: initializer,
@@ -778,8 +654,6 @@ class Forest {
       DartType returnType = const DynamicType(),
       AsyncMarker asyncMarker = AsyncMarker.Sync,
       AsyncMarker? dartAsyncMarker}) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new FunctionNode(body,
         typeParameters: typeParameters,
         positionalParameters: positionalParameters,
@@ -807,66 +681,48 @@ class Forest {
 
   FunctionExpression createFunctionExpression(
       int fileOffset, FunctionNode function) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new FunctionExpression(function)..fileOffset = fileOffset;
   }
 
   Expression createExpressionInvocation(
       int fileOffset, Expression expression, Arguments arguments) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new ExpressionInvocation(expression, arguments)
       ..fileOffset = fileOffset;
   }
 
   Expression createMethodInvocation(
       int fileOffset, Expression expression, Name name, Arguments arguments) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new MethodInvocation(expression, name, arguments)
       ..fileOffset = fileOffset;
   }
 
   NamedExpression createNamedExpression(
       int fileOffset, String name, Expression expression) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new NamedExpression(name, expression)..fileOffset = fileOffset;
   }
 
   StaticInvocation createStaticInvocation(
       int fileOffset, Procedure procedure, Arguments arguments) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new StaticInvocation(procedure, arguments)..fileOffset = fileOffset;
   }
 
   SuperMethodInvocation createSuperMethodInvocation(
       int fileOffset, Name name, Procedure procedure, Arguments arguments) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new SuperMethodInvocation(name, arguments, procedure)
       ..fileOffset = fileOffset;
   }
 
   NullCheck createNullCheck(int fileOffset, Expression expression) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new NullCheck(expression)..fileOffset = fileOffset;
   }
 
   Expression createPropertyGet(int fileOffset, Expression receiver, Name name) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new PropertyGet(receiver, name)..fileOffset = fileOffset;
   }
 
   Expression createPropertySet(
       int fileOffset, Expression receiver, Name name, Expression value,
       {required bool forEffect, bool readOnlyReceiver = false}) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new PropertySet(receiver, name, value,
         forEffect: forEffect, readOnlyReceiver: readOnlyReceiver)
       ..fileOffset = fileOffset;
@@ -874,25 +730,17 @@ class Forest {
 
   IndexGet createIndexGet(
       int fileOffset, Expression receiver, Expression index) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new IndexGet(receiver, index)..fileOffset = fileOffset;
   }
 
   IndexSet createIndexSet(
       int fileOffset, Expression receiver, Expression index, Expression value,
       {required bool forEffect}) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
-    // ignore: unnecessary_null_comparison
-    assert(forEffect != null);
     return new IndexSet(receiver, index, value, forEffect: forEffect)
       ..fileOffset = fileOffset;
   }
 
   VariableGet createVariableGet(int fileOffset, VariableDeclaration variable) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new VariableGetImpl(variable, forNullGuardedAccess: false)
       ..fileOffset = fileOffset;
   }
@@ -900,47 +748,33 @@ class Forest {
   EqualsExpression createEquals(
       int fileOffset, Expression left, Expression right,
       {required bool isNot}) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
-    // ignore: unnecessary_null_comparison
-    assert(isNot != null);
     return new EqualsExpression(left, right, isNot: isNot)
       ..fileOffset = fileOffset;
   }
 
   BinaryExpression createBinary(
       int fileOffset, Expression left, Name binaryName, Expression right) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new BinaryExpression(left, binaryName, right)
       ..fileOffset = fileOffset;
   }
 
   UnaryExpression createUnary(
       int fileOffset, Name unaryName, Expression expression) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new UnaryExpression(unaryName, expression)..fileOffset = fileOffset;
   }
 
   ParenthesizedExpression createParenthesized(
       int fileOffset, Expression expression) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new ParenthesizedExpression(expression)..fileOffset = fileOffset;
   }
 
   ConstructorTearOff createConstructorTearOff(int fileOffset, Member target) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     assert(target is Constructor || (target is Procedure && target.isFactory),
         "Unexpected constructor tear off target: $target");
     return new ConstructorTearOff(target)..fileOffset = fileOffset;
   }
 
   StaticTearOff createStaticTearOff(int fileOffset, Procedure procedure) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     assert(procedure.kind == ProcedureKind.Method,
         "Unexpected static tear off target: $procedure");
     assert(!procedure.isRedirectingFactory,
@@ -949,24 +783,18 @@ class Forest {
   }
 
   StaticGet createStaticGet(int fileOffset, Member target) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     assert(target is Field || (target is Procedure && target.isGetter));
     return new StaticGet(target)..fileOffset = fileOffset;
   }
 
   RedirectingFactoryTearOff createRedirectingFactoryTearOff(
       int fileOffset, Procedure procedure) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     assert(procedure.isRedirectingFactory);
     return new RedirectingFactoryTearOff(procedure)..fileOffset = fileOffset;
   }
 
   Instantiation createInstantiation(
       int fileOffset, Expression expression, List<DartType> typeArguments) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new Instantiation(expression, typeArguments)
       ..fileOffset = fileOffset;
   }
@@ -976,8 +804,6 @@ class Forest {
       List<TypeParameter> typeParameters,
       Expression expression,
       List<DartType> typeArguments) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     return new TypedefTearOff(typeParameters, expression, typeArguments)
       ..fileOffset = fileOffset;
   }

pkg/front_end/lib/src/fasta/kernel/forwarding_node.dart

@@ -244,8 +244,6 @@ class ForwardingNode {
   void _createForwardingImplIfNeeded(FunctionNode function, Name name,
       Class enclosingClass, Member? superTarget,
       {required bool isForwardingStub}) {
-    // ignore: unnecessary_null_comparison
-    assert(isForwardingStub != null);
     if (function.body != null) {
       // There is already an implementation; nothing further needs to be done.
       return;
@@ -268,9 +266,6 @@ class ForwardingNode {
     bool isForwardingSemiStub = isForwardingStub && !procedure.isSynthetic;
     bool needsSignatureType = false;
     Expression superCall;
-    // ignore: unnecessary_null_comparison
-    assert(superTarget != null,
-        "No super target found for '${name}' in ${enclosingClass}.");
     assert(
         !superTarget.isAbstract,
         "Abstract super target $superTarget found for '${name}' in "

pkg/front_end/lib/src/fasta/kernel/hierarchy/class_member.dart

@@ -152,11 +152,7 @@ abstract class SynthesizedMember extends ClassMember {
   final bool isProperty;
 
   SynthesizedMember(this.classBuilder, this.name,
-      {required this.forSetter, required this.isProperty})
+      {required this.forSetter, required this.isProperty});
-      // ignore: unnecessary_null_comparison
-      : assert(forSetter != null),
-        // ignore: unnecessary_null_comparison
-        assert(isProperty != null);
 
   @override
   List<ClassMember> get declarations => throw new UnimplementedError();
@@ -508,11 +504,7 @@ class InheritedClassMemberImplementsInterface extends SynthesizedMember {
       required this.implementedInterfaceMember,
       required bool isProperty,
       required bool forSetter})
-      // ignore: unnecessary_null_comparison
+      : super(classBuilder, name, isProperty: isProperty, forSetter: forSetter);
-      : assert(inheritedClassMember != null),
-        // ignore: unnecessary_null_comparison
-        assert(implementedInterfaceMember != null),
-        super(classBuilder, name, isProperty: isProperty, forSetter: forSetter);
 
   void _ensureMemberAndCovariance(ClassMembersBuilder membersBuilder) {
     if (_member == null) {

pkg/front_end/lib/src/fasta/kernel/hierarchy/hierarchy_builder.dart

@@ -150,8 +150,6 @@ class ClassHierarchyBuilder
 
     for (int i = 0; i < nodes2.length; i++) {
       ClassHierarchyNode node = nodes2[i];
-      // ignore: unnecessary_null_comparison
-      if (node == null) continue;
       if (node.classBuilder.cls.isAnonymousMixin) {
         // Never find unnamed mixin application in least upper bound.
         continue;

pkg/front_end/lib/src/fasta/kernel/hierarchy/hierarchy_node.dart

@@ -43,8 +43,6 @@ class ClassHierarchyNodeBuilder {
       if (supernode == null) {
         supernode = hierarchy.getNodeFromClassBuilder(objectClass);
       }
-      // ignore: unnecessary_null_comparison
-      assert(supernode != null);
     }
 
     List<Supertype> superclasses;
@@ -157,11 +155,8 @@ class ClassHierarchyNodeBuilder {
     for (Supertype superclass in superclasses) {
       recordSupertype(superclass);
     }
-    // ignore: unnecessary_null_comparison
+    for (Supertype superinterface in interfacesList) {
-    if (interfacesList != null) {
+      recordSupertype(superinterface);
-      for (Supertype superinterface in interfacesList) {
-        recordSupertype(superinterface);
-      }
     }
 
     return new ClassHierarchyNode(classBuilder, supernode, mixedInNode,
@@ -224,14 +219,10 @@ class ClassHierarchyNodeBuilder {
 
   void addInterface(Map<Class, Supertype> interfaces,
       List<Supertype> superclasses, Supertype type) {
-    // ignore: unnecessary_null_comparison
-    if (type == null) return null;
     if (!classBuilder.libraryBuilder.isNonNullableByDefault) {
       type = legacyErasureSupertype(type);
     }
     ClassHierarchyNode node = hierarchy.getNodeFromClass(type.classNode);
-    // ignore: unnecessary_null_comparison
-    if (node == null) return null;
     int depth = node.depth;
     int myDepth = superclasses.length;
     Supertype? superclass = depth < myDepth ? superclasses[depth] : null;

pkg/front_end/lib/src/fasta/kernel/hierarchy/members_node.dart

@@ -252,8 +252,6 @@ class ClassMembersNodeBuilder {
       }
 
       void inferFrom(List<ClassMember> members, {required bool forSetter}) {
-        // ignore: unnecessary_null_comparison
-        assert(forSetter != null);
         CombinedClassMemberSignature combinedMemberSignature =
             new CombinedClassMemberSignature(
                 membersBuilder, classBuilder, members,
@@ -317,8 +315,6 @@ class ClassMembersNodeBuilder {
       }
 
       void inferFrom(List<ClassMember> members, {required bool forSetter}) {
-        // ignore: unnecessary_null_comparison
-        assert(forSetter != null);
         CombinedClassMemberSignature combinedMemberSignature =
             new CombinedClassMemberSignature(
                 membersBuilder, classBuilder, members,
@@ -418,8 +414,6 @@ class ClassMembersNodeBuilder {
 
       DartType? inferFrom(List<ClassMember> members,
           {required bool forSetter}) {
-        // ignore: unnecessary_null_comparison
-        assert(forSetter != null);
         CombinedClassMemberSignature combinedMemberSignature =
             new CombinedClassMemberSignature(
                 membersBuilder, classBuilder, members,
@@ -917,8 +911,7 @@ class ClassMembersNodeBuilder {
             "Only inherited members can implement by inheritance: "
             "${inheritedMember}");
         inheritedImplementsMap[inheritedMember] = overrides;
-        // ignore: unnecessary_null_comparison
+        if (dataForTesting != null) {
-        if (dataForTesting != null && aliasForTesting != null) {
           dataForTesting.aliasMap[aliasForTesting] = inheritedMember;
         }
       }

pkg/front_end/lib/src/fasta/kernel/internal_ast.dart

@@ -253,11 +253,7 @@ class ForInStatementWithSynthesizedVariable extends InternalStatement {
 
   ForInStatementWithSynthesizedVariable(this.variable, this.iterable,
       this.syntheticAssignment, this.expressionEffects, this.body,
-      {required this.isAsync, required this.hasProblem})
+      {required this.isAsync, required this.hasProblem}) {
-      // ignore: unnecessary_null_comparison
-      : assert(isAsync != null),
-        // ignore: unnecessary_null_comparison
-        assert(hasProblem != null) {
     variable?.parent = this;
     iterable.parent = this;
     syntheticAssignment?.parent = this;
@@ -286,11 +282,7 @@ class TryStatement extends InternalStatement {
   List<Catch> catchBlocks;
   Statement? finallyBlock;
 
-  TryStatement(this.tryBlock, this.catchBlocks, this.finallyBlock)
+  TryStatement(this.tryBlock, this.catchBlocks, this.finallyBlock) {
-      // ignore: unnecessary_null_comparison
-      : assert(tryBlock != null),
-        // ignore: unnecessary_null_comparison
-        assert(catchBlocks != null) {
     tryBlock.parent = this;
     setParents(catchBlocks, this);
     finallyBlock?.parent = this;
@@ -328,9 +320,7 @@ class SwitchCaseImpl extends SwitchCase {
   SwitchCaseImpl(this.caseOffsets, List<Expression> expressions,
       List<int> expressionOffsets, Statement body,
       {bool isDefault = false, required this.hasLabel})
-      // ignore: unnecessary_null_comparison
+      : super(expressions, expressionOffsets, body, isDefault: isDefault);
-      : assert(hasLabel != null),
-        super(expressions, expressionOffsets, body, isDefault: isDefault);
 
   @override
   String toString() {
@@ -342,10 +332,7 @@ class BreakStatementImpl extends BreakStatement {
   Statement? targetStatement;
   final bool isContinue;
 
-  BreakStatementImpl({required this.isContinue})
+  BreakStatementImpl({required this.isContinue}) : super(dummyLabeledStatement);
-      // ignore: unnecessary_null_comparison
-      : assert(isContinue != null),
-        super(dummyLabeledStatement);
 
   @override
   String toString() {
@@ -599,11 +586,7 @@ class Cascade extends InternalExpression {
   /// variable.  Caller is responsible for ensuring that [variable]'s
   /// initializer is the expression preceding the first `..` of the cascade
   /// expression.
-  Cascade(this.variable, {required this.isNullAware})
+  Cascade(this.variable, {required this.isNullAware}) {
-      // ignore: unnecessary_null_comparison
-      : assert(variable != null),
-        // ignore: unnecessary_null_comparison
-        assert(isNullAware != null) {
     variable.parent = this;
   }
 
@@ -651,11 +634,7 @@ class DeferredCheck extends InternalExpression {
   VariableDeclaration variable;
   Expression expression;
 
-  DeferredCheck(this.variable, this.expression)
+  DeferredCheck(this.variable, this.expression) {
-      // ignore: unnecessary_null_comparison
-      : assert(variable != null),
-        // ignore: unnecessary_null_comparison
-        assert(expression != null) {
     variable.parent = this;
     expression.parent = this;
   }
@@ -856,11 +835,7 @@ class IfNullExpression extends InternalExpression {
   Expression left;
   Expression right;
 
-  IfNullExpression(this.left, this.right)
+  IfNullExpression(this.left, this.right) {
-      // ignore: unnecessary_null_comparison
-      : assert(left != null),
-        // ignore: unnecessary_null_comparison
-        assert(right != null) {
     left.parent = this;
     right.parent = this;
   }
@@ -995,9 +970,7 @@ class ShadowInvalidFieldInitializer extends LocalInitializer
 
   ShadowInvalidFieldInitializer(
       this.field, this.value, VariableDeclaration variable)
-      // ignore: unnecessary_null_comparison
+      : super(variable) {
-      : assert(value != null),
-        super(variable) {
     value.parent = this;
   }
 
@@ -1016,11 +989,7 @@ class ExpressionInvocation extends InternalExpression {
   Expression expression;
   Arguments arguments;
 
-  ExpressionInvocation(this.expression, this.arguments)
+  ExpressionInvocation(this.expression, this.arguments) {
-      // ignore: unnecessary_null_comparison
-      : assert(expression != null),
-        // ignore: unnecessary_null_comparison
-        assert(arguments != null) {
     expression.parent = this;
     arguments.parent = this;
   }
@@ -1056,11 +1025,7 @@ class NullAwareMethodInvocation extends InternalExpression {
   /// The expression that invokes the method on [variable].
   Expression invocation;
 
-  NullAwareMethodInvocation(this.variable, this.invocation)
+  NullAwareMethodInvocation(this.variable, this.invocation) {
-      // ignore: unnecessary_null_comparison
-      : assert(variable != null),
-        // ignore: unnecessary_null_comparison
-        assert(invocation != null) {
     variable.parent = this;
     invocation.parent = this;
   }
@@ -1121,11 +1086,7 @@ class NullAwarePropertyGet extends InternalExpression {
   /// The expression that reads the property from [variable].
   Expression read;
 
-  NullAwarePropertyGet(this.variable, this.read)
+  NullAwarePropertyGet(this.variable, this.read) {
-      // ignore: unnecessary_null_comparison
-      : assert(variable != null),
-        // ignore: unnecessary_null_comparison
-        assert(read != null) {
     variable.parent = this;
     read.parent = this;
   }
@@ -1174,11 +1135,7 @@ class NullAwarePropertySet extends InternalExpression {
   /// The expression that writes the value to the property in [variable].
   Expression write;
 
-  NullAwarePropertySet(this.variable, this.write)
+  NullAwarePropertySet(this.variable, this.write) {
-      // ignore: unnecessary_null_comparison
-      : assert(variable != null),
-        // ignore: unnecessary_null_comparison
-        assert(write != null) {
     variable.parent = this;
     write.parent = this;
   }
@@ -1390,9 +1347,7 @@ class VariableGetImpl extends VariableGet {
 
   VariableGetImpl(VariableDeclaration variable,
       {required this.forNullGuardedAccess})
-      // ignore: unnecessary_null_comparison
+      : super(variable);
-      : assert(forNullGuardedAccess != null),
-        super(variable);
 
   @override
   String toString() {
@@ -1481,17 +1436,7 @@ class IfNullPropertySet extends InternalExpression {
   IfNullPropertySet(this.receiver, this.propertyName, this.rhs,
       {required this.forEffect,
       required this.readOffset,
-      required this.writeOffset})
+      required this.writeOffset}) {
-      // ignore: unnecessary_null_comparison
-      : assert(receiver != null),
-        // ignore: unnecessary_null_comparison
-        assert(rhs != null),
-        // ignore: unnecessary_null_comparison
-        assert(forEffect != null),
-        // ignore: unnecessary_null_comparison
-        assert(readOffset != null),
-        // ignore: unnecessary_null_comparison
-        assert(writeOffset != null) {
     receiver.parent = this;
     rhs.parent = this;
   }
@@ -1538,13 +1483,7 @@ class IfNullSet extends InternalExpression {
   /// If `true`, the expression is only need for effect and not for its value.
   final bool forEffect;
 
-  IfNullSet(this.read, this.write, {required this.forEffect})
+  IfNullSet(this.read, this.write, {required this.forEffect}) {
-      // ignore: unnecessary_null_comparison
-      : assert(read != null),
-        // ignore: unnecessary_null_comparison
-        assert(write != null),
-        // ignore: unnecessary_null_comparison
-        assert(forEffect != null) {
     read.parent = this;
     write.parent = this;
   }
@@ -1641,19 +1580,7 @@ class CompoundExtensionSet extends InternalExpression {
       {required this.forEffect,
       required this.readOffset,
       required this.binaryOffset,
-      required this.writeOffset})
+      required this.writeOffset}) {
-      // ignore: unnecessary_null_comparison
-      : assert(receiver != null),
-        // ignore: unnecessary_null_comparison
-        assert(rhs != null),
-        // ignore: unnecessary_null_comparison
-        assert(forEffect != null),
-        // ignore: unnecessary_null_comparison
-        assert(readOffset != null),
-        // ignore: unnecessary_null_comparison
-        assert(binaryOffset != null),
-        // ignore: unnecessary_null_comparison
-        assert(writeOffset != null) {
     receiver.parent = this;
     rhs.parent = this;
   }
@@ -1711,19 +1638,7 @@ class CompoundPropertySet extends InternalExpression {
       {required this.forEffect,
       required this.readOffset,
       required this.binaryOffset,
-      required this.writeOffset})
+      required this.writeOffset}) {
-      // ignore: unnecessary_null_comparison
-      : assert(receiver != null),
-        // ignore: unnecessary_null_comparison
-        assert(rhs != null),
-        // ignore: unnecessary_null_comparison
-        assert(forEffect != null),
-        // ignore: unnecessary_null_comparison
-        assert(readOffset != null),
-        // ignore: unnecessary_null_comparison
-        assert(binaryOffset != null),
-        // ignore: unnecessary_null_comparison
-        assert(writeOffset != null) {
     receiver.parent = this;
     rhs.parent = this;
   }
@@ -1772,11 +1687,7 @@ class PropertyPostIncDec extends InternalExpression {
   /// property on [variable].
   VariableDeclarationImpl write;
 
-  PropertyPostIncDec(this.variable, this.read, this.write)
+  PropertyPostIncDec(this.variable, this.read, this.write) {
-      // ignore: unnecessary_null_comparison
-      : assert(read != null),
-        // ignore: unnecessary_null_comparison
-        assert(write != null) {
     variable?.parent = this;
     read.parent = this;
     write.parent = this;
@@ -1813,11 +1724,7 @@ class LocalPostIncDec extends InternalExpression {
   /// local variable.
   VariableDeclarationImpl write;
 
-  LocalPostIncDec(this.read, this.write)
+  LocalPostIncDec(this.read, this.write) {
-      // ignore: unnecessary_null_comparison
-      : assert(read != null),
-        // ignore: unnecessary_null_comparison
-        assert(write != null) {
     read.parent = this;
     write.parent = this;
   }
@@ -1849,11 +1756,7 @@ class StaticPostIncDec extends InternalExpression {
   /// static member.
   VariableDeclarationImpl write;
 
-  StaticPostIncDec(this.read, this.write)
+  StaticPostIncDec(this.read, this.write) {
-      // ignore: unnecessary_null_comparison
-      : assert(read != null),
-        // ignore: unnecessary_null_comparison
-        assert(write != null) {
     read.parent = this;
     write.parent = this;
   }
@@ -1885,11 +1788,7 @@ class SuperPostIncDec extends InternalExpression {
   /// static member.
   VariableDeclarationImpl write;
 
-  SuperPostIncDec(this.read, this.write)
+  SuperPostIncDec(this.read, this.write) {
-      // ignore: unnecessary_null_comparison
-      : assert(read != null),
-        // ignore: unnecessary_null_comparison
-        assert(write != null) {
     read.parent = this;
     write.parent = this;
   }
@@ -1914,11 +1813,7 @@ class IndexGet extends InternalExpression {
   /// The index expression of the operation.
   Expression index;
 
-  IndexGet(this.receiver, this.index)
+  IndexGet(this.receiver, this.index) {
-      // ignore: unnecessary_null_comparison
-      : assert(receiver != null),
-        // ignore: unnecessary_null_comparison
-        assert(index != null) {
     receiver.parent = this;
     index.parent = this;
   }
@@ -1968,15 +1863,7 @@ class IndexSet extends InternalExpression {
 
   final bool forEffect;
 
-  IndexSet(this.receiver, this.index, this.value, {required this.forEffect})
+  IndexSet(this.receiver, this.index, this.value, {required this.forEffect}) {
-      // ignore: unnecessary_null_comparison
-      : assert(receiver != null),
-        // ignore: unnecessary_null_comparison
-        assert(index != null),
-        // ignore: unnecessary_null_comparison
-        assert(value != null),
-        // ignore: unnecessary_null_comparison
-        assert(forEffect != null) {
     receiver.parent = this;
     index.parent = this;
     value.parent = this;
@@ -2026,11 +1913,7 @@ class SuperIndexSet extends InternalExpression {
   /// The value expression of the operation.
   Expression value;
 
-  SuperIndexSet(this.setter, this.index, this.value)
+  SuperIndexSet(this.setter, this.index, this.value) {
-      // ignore: unnecessary_null_comparison
-      : assert(index != null),
-        // ignore: unnecessary_null_comparison
-        assert(value != null) {
     index.parent = this;
     value.parent = this;
   }
@@ -2088,13 +1971,7 @@ class ExtensionIndexSet extends InternalExpression {
   ExtensionIndexSet(this.extension, this.explicitTypeArguments, this.receiver,
       this.setter, this.index, this.value)
       : assert(explicitTypeArguments == null ||
-            explicitTypeArguments.length == extension.typeParameters.length),
+            explicitTypeArguments.length == extension.typeParameters.length) {
-        // ignore: unnecessary_null_comparison
-        assert(receiver != null),
-        // ignore: unnecessary_null_comparison
-        assert(index != null),
-        // ignore: unnecessary_null_comparison
-        assert(value != null) {
     receiver.parent = this;
     index.parent = this;
     value.parent = this;
@@ -2175,21 +2052,7 @@ class IfNullIndexSet extends InternalExpression {
       {required this.readOffset,
       required this.testOffset,
       required this.writeOffset,
-      required this.forEffect})
+      required this.forEffect}) {
-      // ignore: unnecessary_null_comparison
-      : assert(receiver != null),
-        // ignore: unnecessary_null_comparison
-        assert(index != null),
-        // ignore: unnecessary_null_comparison
-        assert(value != null),
-        // ignore: unnecessary_null_comparison
-        assert(readOffset != null),
-        // ignore: unnecessary_null_comparison
-        assert(testOffset != null),
-        // ignore: unnecessary_null_comparison
-        assert(writeOffset != null),
-        // ignore: unnecessary_null_comparison
-        assert(forEffect != null) {
     receiver.parent = this;
     index.parent = this;
     value.parent = this;
@@ -2255,19 +2118,7 @@ class IfNullSuperIndexSet extends InternalExpression {
       {required this.readOffset,
       required this.testOffset,
       required this.writeOffset,
-      required this.forEffect})
+      required this.forEffect}) {
-      // ignore: unnecessary_null_comparison
-      : assert(index != null),
-        // ignore: unnecessary_null_comparison
-        assert(value != null),
-        // ignore: unnecessary_null_comparison
-        assert(readOffset != null),
-        // ignore: unnecessary_null_comparison
-        assert(testOffset != null),
-        // ignore: unnecessary_null_comparison
-        assert(writeOffset != null),
-        // ignore: unnecessary_null_comparison
-        assert(forEffect != null) {
     index.parent = this;
     value.parent = this;
   }
@@ -2342,21 +2193,7 @@ class IfNullExtensionIndexSet extends InternalExpression {
       required this.writeOffset,
       required this.forEffect})
       : assert(explicitTypeArguments == null ||
-            explicitTypeArguments.length == extension.typeParameters.length),
+            explicitTypeArguments.length == extension.typeParameters.length) {
-        // ignore: unnecessary_null_comparison
-        assert(receiver != null),
-        // ignore: unnecessary_null_comparison
-        assert(index != null),
-        // ignore: unnecessary_null_comparison
-        assert(value != null),
-        // ignore: unnecessary_null_comparison
-        assert(readOffset != null),
-        // ignore: unnecessary_null_comparison
-        assert(testOffset != null),
-        // ignore: unnecessary_null_comparison
-        assert(writeOffset != null),
-        // ignore: unnecessary_null_comparison
-        assert(forEffect != null) {
     receiver.parent = this;
     index.parent = this;
     value.parent = this;
@@ -2421,23 +2258,7 @@ class CompoundIndexSet extends InternalExpression {
       required this.binaryOffset,
       required this.writeOffset,
       required this.forEffect,
-      required this.forPostIncDec})
+      required this.forPostIncDec}) {
-      // ignore: unnecessary_null_comparison
-      : assert(receiver != null),
-        // ignore: unnecessary_null_comparison
-        assert(index != null),
-        // ignore: unnecessary_null_comparison
-        assert(rhs != null),
-        // ignore: unnecessary_null_comparison
-        assert(readOffset != null),
-        // ignore: unnecessary_null_comparison
-        assert(binaryOffset != null),
-        // ignore: unnecessary_null_comparison
-        assert(writeOffset != null),
-        // ignore: unnecessary_null_comparison
-        assert(forEffect != null),
-        // ignore: unnecessary_null_comparison
-        assert(forPostIncDec != null) {
     receiver.parent = this;
     index.parent = this;
     rhs.parent = this;
@@ -2546,21 +2367,7 @@ class NullAwareCompoundSet extends InternalExpression {
       required this.binaryOffset,
       required this.writeOffset,
       required this.forEffect,
-      required this.forPostIncDec})
+      required this.forPostIncDec}) {
-      // ignore: unnecessary_null_comparison
-      : assert(receiver != null),
-        // ignore: unnecessary_null_comparison
-        assert(rhs != null),
-        // ignore: unnecessary_null_comparison
-        assert(readOffset != null),
-        // ignore: unnecessary_null_comparison
-        assert(binaryOffset != null),
-        // ignore: unnecessary_null_comparison
-        assert(writeOffset != null),
-        // ignore: unnecessary_null_comparison
-        assert(forEffect != null),
-        // ignore: unnecessary_null_comparison
-        assert(forPostIncDec != null) {
     receiver.parent = this;
     rhs.parent = this;
     fileOffset = binaryOffset;
@@ -2648,19 +2455,7 @@ class NullAwareIfNullSet extends InternalExpression {
       {required this.readOffset,
       required this.writeOffset,
       required this.testOffset,
-      required this.forEffect})
+      required this.forEffect}) {
-      // ignore: unnecessary_null_comparison
-      : assert(receiver != null),
-        // ignore: unnecessary_null_comparison
-        assert(value != null),
-        // ignore: unnecessary_null_comparison
-        assert(readOffset != null),
-        // ignore: unnecessary_null_comparison
-        assert(writeOffset != null),
-        // ignore: unnecessary_null_comparison
-        assert(testOffset != null),
-        // ignore: unnecessary_null_comparison
-        assert(forEffect != null) {
     receiver.parent = this;
     value.parent = this;
   }
@@ -2736,21 +2531,7 @@ class CompoundSuperIndexSet extends InternalExpression {
       required this.binaryOffset,
       required this.writeOffset,
       required this.forEffect,
-      required this.forPostIncDec})
+      required this.forPostIncDec}) {
-      // ignore: unnecessary_null_comparison
-      : assert(index != null),
-        // ignore: unnecessary_null_comparison
-        assert(rhs != null),
-        // ignore: unnecessary_null_comparison
-        assert(readOffset != null),
-        // ignore: unnecessary_null_comparison
-        assert(binaryOffset != null),
-        // ignore: unnecessary_null_comparison
-        assert(writeOffset != null),
-        // ignore: unnecessary_null_comparison
-        assert(forEffect != null),
-        // ignore: unnecessary_null_comparison
-        assert(forPostIncDec != null) {
     index.parent = this;
     rhs.parent = this;
     fileOffset = binaryOffset;
@@ -2839,23 +2620,7 @@ class CompoundExtensionIndexSet extends InternalExpression {
       required this.forEffect,
       required this.forPostIncDec})
       : assert(explicitTypeArguments == null ||
-            explicitTypeArguments.length == extension.typeParameters.length),
+            explicitTypeArguments.length == extension.typeParameters.length) {
-        // ignore: unnecessary_null_comparison
-        assert(receiver != null),
-        // ignore: unnecessary_null_comparison
-        assert(index != null),
-        // ignore: unnecessary_null_comparison
-        assert(rhs != null),
-        // ignore: unnecessary_null_comparison
-        assert(readOffset != null),
-        // ignore: unnecessary_null_comparison
-        assert(binaryOffset != null),
-        // ignore: unnecessary_null_comparison
-        assert(writeOffset != null),
-        // ignore: unnecessary_null_comparison
-        assert(forEffect != null),
-        // ignore: unnecessary_null_comparison
-        assert(forPostIncDec != null) {
     receiver.parent = this;
     index.parent = this;
     rhs.parent = this;
@@ -2914,16 +2679,9 @@ class ExtensionSet extends InternalExpression {
   final bool forEffect;
 
   ExtensionSet(this.extension, this.explicitTypeArguments, this.receiver,
-      this.target, this.value,
+      this.target, this.value, {required this.forEffect})
-      {required this.forEffect})
       : assert(explicitTypeArguments == null ||
-            explicitTypeArguments.length == extension.typeParameters.length),
+            explicitTypeArguments.length == extension.typeParameters.length) {
-        // ignore: unnecessary_null_comparison
-        assert(receiver != null),
-        // ignore: unnecessary_null_comparison
-        assert(value != null),
-        // ignore: unnecessary_null_comparison
-        assert(forEffect != null) {
     receiver.parent = this;
     value.parent = this;
   }
@@ -2953,11 +2711,7 @@ class NullAwareExtension extends InternalExpression {
   VariableDeclarationImpl variable;
   Expression expression;
 
-  NullAwareExtension(this.variable, this.expression)
+  NullAwareExtension(this.variable, this.expression) {
-      // ignore: unnecessary_null_comparison
-      : assert(variable != null),
-        // ignore: unnecessary_null_comparison
-        assert(expression != null) {
     variable.parent = this;
     expression.parent = this;
   }
@@ -2993,9 +2747,7 @@ class ExtensionTearOff extends InternalExpression {
   /// The arguments provided to the top-level method.
   Arguments arguments;
 
-  ExtensionTearOff(this.target, this.arguments)
+  ExtensionTearOff(this.target, this.arguments) {
-      // ignore: unnecessary_null_comparison
-      : assert(arguments != null) {
     arguments.parent = this;
   }
 
@@ -3017,13 +2769,7 @@ class EqualsExpression extends InternalExpression {
   Expression right;
   bool isNot;
 
-  EqualsExpression(this.left, this.right, {required this.isNot})
+  EqualsExpression(this.left, this.right, {required this.isNot}) {
-      // ignore: unnecessary_null_comparison
-      : assert(left != null),
-        // ignore: unnecessary_null_comparison
-        assert(right != null),
-        // ignore: unnecessary_null_comparison
-        assert(isNot != null) {
     left.parent = this;
     right.parent = this;
   }
@@ -3057,11 +2803,7 @@ class BinaryExpression extends InternalExpression {
   Name binaryName;
   Expression right;
 
-  BinaryExpression(this.left, this.binaryName, this.right)
+  BinaryExpression(this.left, this.binaryName, this.right) {
-      // ignore: unnecessary_null_comparison
-      : assert(left != null),
-        // ignore: unnecessary_null_comparison
-        assert(right != null) {
     left.parent = this;
     right.parent = this;
   }
@@ -3093,9 +2835,7 @@ class UnaryExpression extends InternalExpression {
   Name unaryName;
   Expression expression;
 
-  UnaryExpression(this.unaryName, this.expression)
+  UnaryExpression(this.unaryName, this.expression) {
-      // ignore: unnecessary_null_comparison
-      : assert(expression != null) {
     expression.parent = this;
   }
 
@@ -3128,9 +2868,7 @@ class UnaryExpression extends InternalExpression {
 class ParenthesizedExpression extends InternalExpression {
   Expression expression;
 
-  ParenthesizedExpression(this.expression)
+  ParenthesizedExpression(this.expression) {
-      // ignore: unnecessary_null_comparison
-      : assert(expression != null) {
     expression.parent = this;
   }
 
@@ -3198,11 +2936,7 @@ class MethodInvocation extends InternalExpression {
 
   Arguments arguments;
 
-  MethodInvocation(this.receiver, this.name, this.arguments)
+  MethodInvocation(this.receiver, this.name, this.arguments) {
-      // ignore: unnecessary_null_comparison
-      : assert(receiver != null),
-        // ignore: unnecessary_null_comparison
-        assert(arguments != null) {
     receiver.parent = this;
     arguments.parent = this;
   }
@@ -3240,9 +2974,7 @@ class PropertyGet extends InternalExpression {
 
   Name name;
 
-  PropertyGet(this.receiver, this.name)
+  PropertyGet(this.receiver, this.name) {
-      // ignore: unnecessary_null_comparison
-      : assert(receiver != null) {
     receiver.parent = this;
   }
 
@@ -3286,15 +3018,7 @@ class PropertySet extends InternalExpression {
   final bool readOnlyReceiver;
 
   PropertySet(this.receiver, this.name, this.value,
-      {required this.forEffect, required this.readOnlyReceiver})
+      {required this.forEffect, required this.readOnlyReceiver}) {
-      // ignore: unnecessary_null_comparison
-      : assert(receiver != null),
-        // ignore: unnecessary_null_comparison
-        assert(value != null),
-        // ignore: unnecessary_null_comparison
-        assert(forEffect != null),
-        // ignore: unnecessary_null_comparison
-        assert(readOnlyReceiver != null) {
     receiver.parent = this;
     value.parent = this;
   }

pkg/front_end/lib/src/fasta/kernel/kernel_target.dart

@@ -259,14 +259,11 @@ class KernelTarget extends TargetImplementation {
 
   void _parseCurrentSdkVersion() {
     bool good = false;
-    // ignore: unnecessary_null_comparison
+    List<String> dotSeparatedParts = currentSdkVersionString.split(".");
-    if (currentSdkVersionString != null) {
+    if (dotSeparatedParts.length >= 2) {
-      List<String> dotSeparatedParts = currentSdkVersionString.split(".");
+      _currentSdkVersion = new Version(int.tryParse(dotSeparatedParts[0])!,
-      if (dotSeparatedParts.length >= 2) {
+          int.tryParse(dotSeparatedParts[1])!);
-        _currentSdkVersion = new Version(int.tryParse(dotSeparatedParts[0])!,
+      good = true;
-            int.tryParse(dotSeparatedParts[1])!);
-        good = true;
-      }
     }
     if (!good) {
       throw new StateError(
@@ -1552,8 +1549,7 @@ class KernelTarget extends TargetImplementation {
     constants.ConstantCoverage coverage = constantEvaluationData.coverage;
     coverage.constructorCoverage.forEach((Uri fileUri, Set<Reference> value) {
       Source? source = uriToSource[fileUri];
-      // ignore: unnecessary_null_comparison
+      if (source != null) {
-      if (source != null && fileUri != null) {
         source.constantCoverageConstructors ??= new Set<Reference>();
         source.constantCoverageConstructors!.addAll(value);
       }

pkg/front_end/lib/src/fasta/kernel/late_lowering.dart

@@ -26,8 +26,6 @@ Statement createGetterWithInitializer(CoreTypes coreTypes, int fileOffset,
     required Expression createIsSetRead(),
     required Expression createIsSetWrite(Expression value),
     required IsSetEncoding isSetEncoding}) {
-  // ignore: unnecessary_null_comparison
-  assert(isSetEncoding != null);
   switch (isSetEncoding) {
     case IsSetEncoding.useIsSetField:
       // Generate:
@@ -120,8 +118,6 @@ Statement createGetterWithInitializerWithRecheck(CoreTypes coreTypes,
     required Expression createIsSetWrite(Expression value),
     required IsSetEncoding isSetEncoding,
     required bool forField}) {
-  // ignore: unnecessary_null_comparison
-  assert(forField != null);
   Constructor constructor = forField
       ? coreTypes.lateInitializationFieldAssignedDuringInitializationConstructor
       : coreTypes
@@ -271,10 +267,6 @@ Statement createGetterBodyWithoutInitializer(
     required Expression createIsSetRead(),
     required IsSetEncoding isSetEncoding,
     required bool forField}) {
-  // ignore: unnecessary_null_comparison
-  assert(forField != null);
-  // ignore: unnecessary_null_comparison
-  assert(isSetEncoding != null);
   Expression exception = new Throw(
       new ConstructorInvocation(
           forField
@@ -356,8 +348,6 @@ Statement createSetterBody(CoreTypes coreTypes, int fileOffset, String name,
     required Expression createVariableWrite(Expression value),
     required Expression createIsSetWrite(Expression value),
     required IsSetEncoding isSetEncoding}) {
-  // ignore: unnecessary_null_comparison
-  assert(isSetEncoding != null);
   Statement createReturn(Expression value) {
     if (shouldReturnValue) {
       return new ReturnStatement(value)..fileOffset = fileOffset;
@@ -406,10 +396,6 @@ Statement createSetterBodyFinal(CoreTypes coreTypes, int fileOffset,
     required Expression createIsSetWrite(Expression value),
     required IsSetEncoding isSetEncoding,
     required bool forField}) {
-  // ignore: unnecessary_null_comparison
-  assert(forField != null);
-  // ignore: unnecessary_null_comparison
-  assert(isSetEncoding != null);
   Expression exception = new Throw(
       new ConstructorInvocation(
           forField

pkg/front_end/lib/src/fasta/kernel/member_covariance.dart

@@ -155,8 +155,6 @@ class Covariance {
   /// aspect of [member]. Otherwise, the covariance for the getter/method aspect
   /// of [member] is computed.
   factory Covariance.fromMember(Member member, {required bool forSetter}) {
-    // ignore: unnecessary_null_comparison
-    assert(forSetter != null);
     if (member is Procedure) {
       if (member.kind == ProcedureKind.Getter) {
         return const Covariance.empty();

pkg/front_end/lib/src/fasta/kernel/type_algorithms.dart

@@ -168,13 +168,6 @@ int computeTypeVariableBuilderVariance(TypeVariableBuilder variable,
 /// type parameter occurrence or on the type argument replacing it.
 NullabilityBuilder combineNullabilityBuildersForSubstitution(
     NullabilityBuilder a, NullabilityBuilder b) {
-  assert(
-      // ignore: unnecessary_null_comparison
-      a != null && b != null,
-      "Both arguments to combineNullabilityBuildersForSubstitution "
-      "should be identical to either 'const NullabilityBuilder.nullable()' or "
-      "'const NullabilityBuilder.omitted()'.");
-
   if (identical(a, const NullabilityBuilder.inherent()) &&
       identical(b, const NullabilityBuilder.inherent())) {
     return const NullabilityBuilder.inherent();
@@ -219,14 +212,6 @@ TypeBuilder substituteRange(
     List<TypeBuilder>? arguments;
     TypeDeclarationBuilder? declaration = type.declaration;
     if (declaration == null) {
-      // ignore: unnecessary_null_comparison
-      assert(unboundTypes != null,
-          "Can not handle unbound named type builders without `unboundTypes`.");
-      assert(
-          // ignore: unnecessary_null_comparison
-          unboundTypeVariables != null,
-          "Can not handle unbound named type builders without "
-          "`unboundTypeVariables`.");
       assert(
           identical(upperSubstitution, lowerSubstitution),
           "Can only handle unbound named type builders identical "
@@ -445,11 +430,6 @@ List<TypeBuilder> calculateBounds(List<TypeVariableBuilder> variables,
     TypeBuilder dynamicType, TypeBuilder bottomType,
     {required List<TypeBuilder> unboundTypes,
     required List<TypeVariableBuilder> unboundTypeVariables}) {
-  // ignore: unnecessary_null_comparison
-  assert(unboundTypes != null);
-  // ignore: unnecessary_null_comparison
-  assert(unboundTypeVariables != null);
-
   List<TypeBuilder> bounds = new List<TypeBuilder>.generate(
       variables.length, (int i) => variables[i].bound ?? dynamicType,
       growable: false);
@@ -1084,8 +1064,6 @@ void breakCycles(List<List<RawTypeCycleElement>> cycles) {
 /// Finds generic function type sub-terms in [type].
 void findUnaliasedGenericFunctionTypes(TypeBuilder? type,
     {required List<FunctionTypeBuilder> result}) {
-  // ignore: unnecessary_null_comparison
-  assert(result != null);
   if (type is FunctionTypeBuilder) {
     if (type.typeVariables != null && type.typeVariables!.length > 0) {
       result.add(type);
@@ -1114,8 +1092,6 @@ void findUnaliasedGenericFunctionTypes(TypeBuilder? type,
 /// Finds generic function type sub-terms in [type] including the aliased ones.
 void findGenericFunctionTypes(TypeBuilder? type,
     {required List<TypeBuilder> result}) {
-  // ignore: unnecessary_null_comparison
-  assert(result != null);
   if (type is FunctionTypeBuilder) {
     if (type.typeVariables != null && type.typeVariables!.length > 0) {
       result.add(type);

pkg/front_end/lib/src/fasta/kernel/type_labeler.dart

@@ -31,9 +31,6 @@ class TypeLabeler implements DartTypeVisitor<void>, ConstantVisitor<void> {
   /// pretty-printed, the returned list can be converted to its string
   /// representation (with labels on duplicated names) by the `join()` method.
   List<Object> labelType(DartType type) {
-    // TODO(askesc): Remove null check when we are completely null clean here.
-    // ignore: unnecessary_null_comparison
-    if (type == null) return ["null-type"];
     result = [];
     type.accept(this);
     return result;
@@ -44,9 +41,6 @@ class TypeLabeler implements DartTypeVisitor<void>, ConstantVisitor<void> {
   /// pretty-printed, the returned list can be converted to its string
   /// representation (with labels on duplicated names) by the `join()` method.
   List<Object> labelConstant(Constant constant) {
-    // TODO(askesc): Remove null check when we are completely null clean here.
-    // ignore: unnecessary_null_comparison
-    if (constant == null) return ["null-constant"];
     result = [];
     constant.accept(this);
     return result;

pkg/front_end/lib/src/fasta/library_graph.dart

@@ -32,8 +32,7 @@ class LibraryGraph implements Graph<Uri> {
       Uri uri2 = dependency.targetLibrary.fileUri;
       if (libraries.containsKey(uri1)) {
         yield uri1;
-        // ignore: unnecessary_null_comparison
+      } else {
-      } else if (uri2 != null) {
         if (libraries.containsKey(uri2)) {
           yield uri2;
         }

pkg/front_end/lib/src/fasta/scope.dart

@@ -149,10 +149,7 @@ class MutableScope {
   final ScopeKind kind;
 
   MutableScope(this.kind, this._local, this._setters, this._extensions,
-      this._parent, this.classNameOrDebugName) {
+      this._parent, this.classNameOrDebugName);
-    // ignore: unnecessary_null_comparison
-    assert(classNameOrDebugName != null);
-  }
 
   Scope? get parent => _parent;
 

pkg/front_end/lib/src/fasta/source/diet_listener.dart

@@ -827,10 +827,6 @@ class DietListener extends StackListenerImpl {
         builder.computeTypeParameterScope(memberScope);
     final Scope formalParameterScope =
         builder.computeFormalParameterScope(typeParameterScope);
-    // ignore: unnecessary_null_comparison
-    assert(typeParameterScope != null);
-    // ignore: unnecessary_null_comparison
-    assert(formalParameterScope != null);
     return createListener(
         builder.bodyBuilderContext, builder, typeParameterScope,
         thisVariable: builder.thisVariable,

pkg/front_end/lib/src/fasta/source/name_scheme.dart

@@ -22,11 +22,7 @@ class NameScheme {
       required this.containerName,
       required this.containerType,
       required this.libraryName})
-      // ignore: unnecessary_null_comparison
+      : assert((containerName == null) ==
-      : assert(isInstanceMember != null),
-        // ignore: unnecessary_null_comparison
-        assert(libraryName != null),
-        assert((containerName == null) ==
             (containerType == ContainerType.Library));
 
   bool get isStatic => !isInstanceMember;

pkg/front_end/lib/src/fasta/source/source_class_builder.dart

@@ -536,13 +536,10 @@ class SourceClassBuilder extends ClassBuilderImpl
         for (int i = 0; i < variables.length; i++) {
           DartType argument =
               i < arguments.length ? arguments[i] : const DynamicType();
-          // ignore: unnecessary_null_comparison
+          // TODO(ahe): Investigate if requiring the caller to use
-          if (substitutionMap != null) {
+          // `substituteDeep` from `package:kernel/type_algebra.dart` instead
-            // TODO(ahe): Investigate if requiring the caller to use
+          // of `substitute` is faster. If so, we can simply this code.
-            // `substituteDeep` from `package:kernel/type_algebra.dart` instead
+          argument = substitute(argument, substitutionMap);
-            // of `substitute` is faster. If so, we can simply this code.
-            argument = substitute(argument, substitutionMap);
-          }
           directSubstitutionMap[variables[i]] = argument;
         }
         substitutionMap = directSubstitutionMap;
@@ -1040,50 +1037,39 @@ class SourceClassBuilder extends ClassBuilderImpl
         procedure.function.namedParameters;
     DartType returnType = procedure.function.returnType;
 
-    // ignore: unnecessary_null_comparison
+    for (TypeParameter functionParameter in functionTypeParameters) {
-    if (functionTypeParameters != null) {
-      for (TypeParameter functionParameter in functionTypeParameters) {
-        for (TypeParameter typeParameter in typeParameters) {
-          int typeVariance = Variance.combine(Variance.invariant,
-              computeVariance(typeParameter, functionParameter.bound));
-          reportVariancePositionIfInvalid(typeVariance, typeParameter, fileUri,
-              functionParameter.fileOffset);
-        }
-      }
-    }
-    // ignore: unnecessary_null_comparison
-    if (positionalParameters != null) {
-      for (VariableDeclaration formal in positionalParameters) {
-        if (!formal.isCovariantByDeclaration) {
-          for (TypeParameter typeParameter in typeParameters) {
-            int formalVariance = Variance.combine(Variance.contravariant,
-                computeVariance(typeParameter, formal.type));
-            reportVariancePositionIfInvalid(
-                formalVariance, typeParameter, fileUri, formal.fileOffset);
-          }
-        }
-      }
-    }
-    // ignore: unnecessary_null_comparison
-    if (namedParameters != null) {
-      for (VariableDeclaration named in namedParameters) {
-        for (TypeParameter typeParameter in typeParameters) {
-          int namedVariance = Variance.combine(Variance.contravariant,
-              computeVariance(typeParameter, named.type));
-          reportVariancePositionIfInvalid(
-              namedVariance, typeParameter, fileUri, named.fileOffset);
-        }
-      }
-    }
-    // ignore: unnecessary_null_comparison
-    if (returnType != null) {
       for (TypeParameter typeParameter in typeParameters) {
-        int returnTypeVariance = computeVariance(typeParameter, returnType);
+        int typeVariance = Variance.combine(Variance.invariant,
-        reportVariancePositionIfInvalid(returnTypeVariance, typeParameter,
+            computeVariance(typeParameter, functionParameter.bound));
-            fileUri, procedure.function.fileOffset,
+        reportVariancePositionIfInvalid(
-            isReturnType: true);
+            typeVariance, typeParameter, fileUri, functionParameter.fileOffset);
       }
     }
+    for (VariableDeclaration formal in positionalParameters) {
+      if (!formal.isCovariantByDeclaration) {
+        for (TypeParameter typeParameter in typeParameters) {
+          int formalVariance = Variance.combine(Variance.contravariant,
+              computeVariance(typeParameter, formal.type));
+          reportVariancePositionIfInvalid(
+              formalVariance, typeParameter, fileUri, formal.fileOffset);
+        }
+      }
+    }
+    for (VariableDeclaration named in namedParameters) {
+      for (TypeParameter typeParameter in typeParameters) {
+        int namedVariance = Variance.combine(
+            Variance.contravariant, computeVariance(typeParameter, named.type));
+        reportVariancePositionIfInvalid(
+            namedVariance, typeParameter, fileUri, named.fileOffset);
+      }
+    }
+
+    for (TypeParameter typeParameter in typeParameters) {
+      int returnTypeVariance = computeVariance(typeParameter, returnType);
+      reportVariancePositionIfInvalid(returnTypeVariance, typeParameter,
+          fileUri, procedure.function.fileOffset,
+          isReturnType: true);
+    }
   }
 
   void reportVariancePositionIfInvalid(
@@ -1406,75 +1392,72 @@ class SourceClassBuilder extends ClassBuilderImpl
             }
           }
 
-          // ignore: unnecessary_null_comparison
+          Builder? targetBuilder = redirectionTarget.target;
-          if (redirectionTarget != null) {
+          if (declaration.next == null) {
-            Builder? targetBuilder = redirectionTarget.target;
+            // Only the first one (that is, the last on in the linked list)
-            if (declaration.next == null) {
+            // is actually in the kernel tree. This call creates a StaticGet
-              // Only the first one (that is, the last on in the linked list)
+            // to [declaration.target] in a field `_redirecting#` which is
-              // is actually in the kernel tree. This call creates a StaticGet
+            // only legal to do to things in the kernel tree.
-              // to [declaration.target] in a field `_redirecting#` which is
+            Reference? fieldReference;
-              // only legal to do to things in the kernel tree.
+            Reference? getterReference;
-              Reference? fieldReference;
+            if (referencesFromIndexed != null) {
-              Reference? getterReference;
+              Name name =
-              if (referencesFromIndexed != null) {
+                  new Name(redirectingName, referencesFromIndexed!.library);
-                Name name =
+              fieldReference =
-                    new Name(redirectingName, referencesFromIndexed!.library);
+                  referencesFromIndexed!.lookupFieldReference(name);
-                fieldReference =
+              getterReference =
-                    referencesFromIndexed!.lookupFieldReference(name);
+                  referencesFromIndexed!.lookupGetterReference(name);
-                getterReference =
-                    referencesFromIndexed!.lookupGetterReference(name);
-              }
-              _addRedirectingConstructor(
-                  declaration, library, fieldReference, getterReference);
-            }
-            Member? targetNode;
-            if (targetBuilder is FunctionBuilder) {
-              targetNode = targetBuilder.member;
-            } else if (targetBuilder is DillMemberBuilder) {
-              targetNode = targetBuilder.member;
-            } else if (targetBuilder is AmbiguousBuilder) {
-              addProblemForRedirectingFactory(
-                  declaration,
-                  templateDuplicatedDeclarationUse
-                      .withArguments(redirectionTarget.fullNameForErrors),
-                  redirectionTarget.charOffset,
-                  noLength);
-            } else {
-              addProblemForRedirectingFactory(
-                  declaration,
-                  templateRedirectionTargetNotFound
-                      .withArguments(redirectionTarget.fullNameForErrors),
-                  redirectionTarget.charOffset,
-                  noLength);
-            }
-            if (targetNode != null &&
-                targetNode is Constructor &&
-                targetNode.enclosingClass.isAbstract) {
-              addProblemForRedirectingFactory(
-                  declaration,
-                  templateAbstractRedirectedClassInstantiation
-                      .withArguments(redirectionTarget.fullNameForErrors),
-                  redirectionTarget.charOffset,
-                  noLength);
-              targetNode = null;
-            }
-            if (targetNode != null &&
-                targetNode is Constructor &&
-                targetNode.enclosingClass.isEnum) {
-              addProblemForRedirectingFactory(
-                  declaration,
-                  messageEnumFactoryRedirectsToConstructor,
-                  redirectionTarget.charOffset,
-                  noLength);
-              targetNode = null;
-            }
-            if (targetNode != null) {
-              List<DartType> typeArguments = declaration.typeArguments ??
-                  new List<DartType>.filled(
-                      targetNode.enclosingClass!.typeParameters.length,
-                      const UnknownType());
-              declaration.setRedirectingFactoryBody(targetNode, typeArguments);
             }
+            _addRedirectingConstructor(
+                declaration, library, fieldReference, getterReference);
+          }
+          Member? targetNode;
+          if (targetBuilder is FunctionBuilder) {
+            targetNode = targetBuilder.member;
+          } else if (targetBuilder is DillMemberBuilder) {
+            targetNode = targetBuilder.member;
+          } else if (targetBuilder is AmbiguousBuilder) {
+            addProblemForRedirectingFactory(
+                declaration,
+                templateDuplicatedDeclarationUse
+                    .withArguments(redirectionTarget.fullNameForErrors),
+                redirectionTarget.charOffset,
+                noLength);
+          } else {
+            addProblemForRedirectingFactory(
+                declaration,
+                templateRedirectionTargetNotFound
+                    .withArguments(redirectionTarget.fullNameForErrors),
+                redirectionTarget.charOffset,
+                noLength);
+          }
+          if (targetNode != null &&
+              targetNode is Constructor &&
+              targetNode.enclosingClass.isAbstract) {
+            addProblemForRedirectingFactory(
+                declaration,
+                templateAbstractRedirectedClassInstantiation
+                    .withArguments(redirectionTarget.fullNameForErrors),
+                redirectionTarget.charOffset,
+                noLength);
+            targetNode = null;
+          }
+          if (targetNode != null &&
+              targetNode is Constructor &&
+              targetNode.enclosingClass.isEnum) {
+            addProblemForRedirectingFactory(
+                declaration,
+                messageEnumFactoryRedirectsToConstructor,
+                redirectionTarget.charOffset,
+                noLength);
+            targetNode = null;
+          }
+          if (targetNode != null) {
+            List<DartType> typeArguments = declaration.typeArguments ??
+                new List<DartType>.filled(
+                    targetNode.enclosingClass!.typeParameters.length,
+                    const UnknownType());
+            declaration.setRedirectingFactoryBody(targetNode, typeArguments);
           }
         }
       }
@@ -1508,10 +1491,6 @@ class SourceClassBuilder extends ClassBuilderImpl
       callback(Member interfaceMember, bool isSetter),
       {required bool isInterfaceCheck,
       required bool declaredNeedsLegacyErasure}) {
-    // ignore: unnecessary_null_comparison
-    assert(isInterfaceCheck != null);
-    // ignore: unnecessary_null_comparison
-    assert(declaredNeedsLegacyErasure != null);
     if (declaredMember == interfaceMember) {
       return;
     }

pkg/front_end/lib/src/fasta/source/source_extension_builder.dart

@@ -157,8 +157,6 @@ class SourceExtensionBuilder extends ExtensionBuilderImpl
         kind = ExtensionMemberKind.TearOff;
         break;
     }
-    // ignore: unnecessary_null_comparison
-    assert(kind != null);
     extension.members.add(new ExtensionMemberDescriptor(
         name: new Name(name, libraryBuilder.library),
         member: memberReference,

pkg/front_end/lib/src/fasta/source/source_field_builder.dart

@@ -623,14 +623,6 @@ class RegularFieldEncoding implements FieldEncoding {
       required Reference? getterReference,
       required Reference? setterReference,
       required bool isEnumElement}) {
-    // ignore: unnecessary_null_comparison
-    assert(isFinal != null);
-    // ignore: unnecessary_null_comparison
-    assert(isConst != null);
-    // ignore: unnecessary_null_comparison
-    assert(isLate != null);
-    // ignore: unnecessary_null_comparison
-    assert(hasInitializer != null);
     bool isImmutable =
         isLate ? (isFinal && hasInitializer) : (isFinal || isConst);
     _field = isImmutable
@@ -759,9 +751,7 @@ class SourceFieldMember extends BuilderClassMember {
   @override
   final bool forSetter;
 
-  SourceFieldMember(this.memberBuilder, {required this.forSetter})
+  SourceFieldMember(this.memberBuilder, {required this.forSetter});
-      // ignore: unnecessary_null_comparison
-      : assert(forSetter != null);
 
   @override
   void inferType(ClassMembersBuilder membersBuilder) {
@@ -1011,8 +1001,6 @@ abstract class AbstractLateFieldEncoding implements FieldEncoding {
 
   Procedure? _createSetter(Uri fileUri, int charOffset, Reference? reference,
       {required bool isCovariantByDeclaration}) {
-    // ignore: unnecessary_null_comparison
-    assert(isCovariantByDeclaration != null);
     VariableDeclaration parameter = new VariableDeclaration("${name}#param")
       ..isCovariantByDeclaration = isCovariantByDeclaration
       ..fileOffset = fileOffset;
@@ -1433,9 +1421,7 @@ class _SynthesizedFieldClassMember implements ClassMember {
   final bool isInternalImplementation;
 
   _SynthesizedFieldClassMember(this.fieldBuilder, this._member, this._kind,
-      {this.forSetter = false, required this.isInternalImplementation})
+      {this.forSetter = false, required this.isInternalImplementation});
-      // ignore: unnecessary_null_comparison
-      : assert(isInternalImplementation != null);
 
   @override
   Member getMember(ClassMembersBuilder membersBuilder) {
@@ -1519,10 +1505,7 @@ class _SynthesizedFieldClassMember implements ClassMember {
   String get fullName {
     String suffix = isSetter ? "=" : "";
     String className = classBuilder.fullNameForErrors;
-    // ignore: unnecessary_null_comparison
+    return "${className}.${fullNameForErrors}$suffix";
-    return className == null
-        ? "${fullNameForErrors}$suffix"
-        : "${className}.${fullNameForErrors}$suffix";
   }
 
   @override
@@ -1591,17 +1574,7 @@ class AbstractOrExternalFieldEncoding implements FieldEncoding {
       required bool isFinal,
       required bool isCovariantByDeclaration,
       required bool isNonNullableByDefault})
-      // ignore: unnecessary_null_comparison
+      : _isExtensionInstanceMember = isExternal &&
-      : assert(isAbstract != null),
-        // ignore: unnecessary_null_comparison
-        assert(isExternal != null),
-        // ignore: unnecessary_null_comparison
-        assert(isFinal != null),
-        // ignore: unnecessary_null_comparison
-        assert(isCovariantByDeclaration != null),
-        // ignore: unnecessary_null_comparison
-        assert(isNonNullableByDefault != null),
-        _isExtensionInstanceMember = isExternal &&
             nameScheme.isExtensionMember &&
             nameScheme.isInstanceMember,
         _isInlineClassInstanceMember = isExternal &&

pkg/front_end/lib/src/fasta/source/source_inline_class_builder.dart

@@ -195,8 +195,6 @@ class SourceInlineClassBuilder extends InlineClassBuilderImpl
         kind = InlineClassMemberKind.TearOff;
         break;
     }
-    // ignore: unnecessary_null_comparison
-    assert(kind != null);
     inlineClass.members.add(new InlineClassMemberDescriptor(
         name: new Name(name, libraryBuilder.library),
         member: memberReference,

pkg/front_end/lib/src/fasta/source/source_library_builder.dart

@@ -1024,11 +1024,6 @@ class SourceLibraryBuilder extends LibraryBuilderImpl {
       SourceLibraryBuilder sourceLibraryBuilder, Scope scope,
       {required bool checkForInstanceVsStaticConflict,
       required bool checkForMethodVsSetterConflict}) {
-    // ignore: unnecessary_null_comparison
-    assert(checkForInstanceVsStaticConflict != null);
-    // ignore: unnecessary_null_comparison
-    assert(checkForMethodVsSetterConflict != null);
-
     scope.forEachLocalSetter((String name, MemberBuilder setter) {
       Builder? getable = scope.lookupLocalMember(name, setter: false);
       if (getable == null) {
@@ -2907,10 +2902,6 @@ class SourceLibraryBuilder extends LibraryBuilderImpl {
       AsyncMarker asyncModifier,
       {required bool isInstanceMember,
       required bool isExtensionMember}) {
-    // ignore: unnecessary_null_comparison
-    assert(isInstanceMember != null);
-    // ignore: unnecessary_null_comparison
-    assert(isExtensionMember != null);
     assert(!isExtensionMember ||
         currentTypeParameterScopeBuilder.kind ==
             TypeParameterScopeKind.extensionDeclaration);
@@ -4337,8 +4328,6 @@ class SourceLibraryBuilder extends LibraryBuilderImpl {
           String enclosingName = issue.enclosingType == null
               ? targetName!
               : getGenericTypeName(issue.enclosingType!);
-          // ignore: unnecessary_null_comparison
-          assert(enclosingName != null);
           if (issueInferred) {
             message = templateIncorrectTypeArgumentInferred.withArguments(
                 argument,
@@ -4577,7 +4566,6 @@ class SourceLibraryBuilder extends LibraryBuilderImpl {
     // TODO(cstefantsova): Find a better way than relying on [interfaceTarget].
     Member? method =
         membersHierarchy.getDispatchTarget(klass, name) ?? interfaceTarget;
-    // ignore: unnecessary_null_comparison
     if (method == null || method is! Procedure) {
       return;
     }
@@ -4669,8 +4657,6 @@ class SourceLibraryBuilder extends LibraryBuilderImpl {
       Uri fileUri,
       int offset,
       {required bool inferred}) {
-    // ignore: unnecessary_null_comparison
-    assert(inferred != null);
     if (typeArguments.isEmpty) return;
 
     List<TypeParameter> functionTypeParameters = functionType.typeParameters;
@@ -5276,10 +5262,7 @@ class TypeParameterScopeBuilder {
       this.extensions,
       this._name,
       this._charOffset,
-      this.parent) {
+      this.parent);
-    // ignore: unnecessary_null_comparison
-    assert(_name != null);
-  }
 
   TypeParameterScopeBuilder.library()
       : this(
@@ -5687,9 +5670,6 @@ List<TypeVariableBuilder> _sortTypeVariablesTopologically(
 
 void _sortTypeVariablesTopologicallyFromRoot(TypeBuilder root,
     Set<TypeVariableBuilder> unhandled, List<TypeVariableBuilder> result) {
-  // ignore: unnecessary_null_comparison
-  assert(root != null);
-
   List<TypeVariableBuilder>? typeVariables;
   List<TypeBuilder>? internalDependents;
 

pkg/front_end/lib/src/fasta/source/source_loader.dart

@@ -412,10 +412,7 @@ class SourceLoader extends Loader {
     Message? packageLanguageVersionProblem;
     if (packageForLanguageVersion != null) {
       Uri importUri = origin?.importUri ?? uri;
-      if (!importUri.isScheme('dart') &&
+      if (!importUri.isScheme('dart') && !importUri.isScheme('package')) {
-          !importUri.isScheme('package') &&
-          // ignore: unnecessary_null_comparison
-          packageForLanguageVersion.name != null) {
         packageUri =
             new Uri(scheme: 'package', path: packageForLanguageVersion.name);
       }
@@ -1205,8 +1202,6 @@ severity: $severity
 
   Future<Null> buildOutline(SourceLibraryBuilder library) async {
     Token tokens = await tokenize(library);
-    // ignore: unnecessary_null_comparison
-    if (tokens == null) return;
     OutlineBuilder listener = new OutlineBuilder(library);
     new ClassMemberParser(listener,
             allowPatterns: library.libraryFeatures.patterns.isEnabled)
@@ -1229,10 +1224,6 @@ severity: $severity
     // second time, and the first time was in [buildOutline] above. So this
     // time we suppress lexical errors.
     Token tokens = await tokenize(library, suppressLexicalErrors: true);
-    // ignore: unnecessary_null_comparison
-    if (tokens == null) {
-      return;
-    }
 
     if (target.benchmarker != null) {
       // When benchmarking we do extra parsing on it's own to get a timing of
@@ -1271,11 +1262,8 @@ severity: $severity
       }
       Token tokens = await tokenize(part as SourceLibraryBuilder,
           suppressLexicalErrors: true);
-      // ignore: unnecessary_null_comparison
+      listener.uri = part.fileUri;
-      if (tokens != null) {
+      parser.parseUnit(tokens);
-        listener.uri = part.fileUri;
-        parser.parseUnit(tokens);
-      }
     }
   }
 

pkg/front_end/lib/src/fasta/source/source_type_alias_builder.dart

@@ -107,28 +107,16 @@ class SourceTypeAliasBuilder extends TypeAliasBuilderImpl {
     // detect cycles by detecting recursive calls to this method using an
     // instance of InvalidType that isn't identical to `const InvalidType()`.
     thisType = pendingTypeAliasMarker;
-    DartType builtType = const InvalidType();
+    DartType builtType = type.build(libraryBuilder, TypeUse.typedefAlias);
-    TypeBuilder type = this.type;
+    if (typeVariables != null) {
-    // ignore: unnecessary_null_comparison
+      for (TypeVariableBuilder tv in typeVariables!) {
-    if (type != null) {
+        // Follow bound in order to find all cycles
-      builtType = type.build(libraryBuilder, TypeUse.typedefAlias);
+        tv.bound?.build(libraryBuilder, TypeUse.typeParameterBound);
-      // ignore: unnecessary_null_comparison
-      if (builtType != null) {
-        if (typeVariables != null) {
-          for (TypeVariableBuilder tv in typeVariables!) {
-            // Follow bound in order to find all cycles
-            tv.bound?.build(libraryBuilder, TypeUse.typeParameterBound);
-          }
-        }
-        if (identical(thisType, cyclicTypeAliasMarker)) {
-          builtType = const InvalidType();
-        } else {
-          builtType = builtType;
-        }
-      } else {
-        builtType = const InvalidType();
       }
     }
+    if (identical(thisType, cyclicTypeAliasMarker)) {
+      builtType = const InvalidType();
+    }
     return thisType = typedef.type ??= builtType;
   }
 

pkg/front_end/lib/src/fasta/source/stack_listener_impl.dart

@@ -89,8 +89,6 @@ abstract class StackListenerImpl extends StackListener {
 
   void reportMissingNonNullableSupport(Token token) {
     assert(!libraryBuilder.isNonNullableByDefault);
-    // ignore: unnecessary_null_comparison
-    assert(token != null);
     if (libraryFeatures.nonNullable.isSupported) {
       if (libraryBuilder.languageVersion.isExplicit) {
         addProblem(

pkg/front_end/lib/src/fasta/type_inference/closure_context.dart

@@ -44,8 +44,6 @@ abstract class ClosureContext {
 
   factory ClosureContext(InferenceVisitorBase inferrer, AsyncMarker asyncMarker,
       DartType returnContext, bool needToInferReturnType) {
-    // ignore: unnecessary_null_comparison
-    assert(returnContext != null);
     DartType declaredReturnType =
         inferrer.computeGreatestClosure(returnContext);
     bool isAsync = asyncMarker == AsyncMarker.Async ||
@@ -326,8 +324,6 @@ class _SyncClosureContext implements ClosureContext {
   DartType inferReturnType(InferenceVisitorBase inferrer,
       {required bool hasImplicitReturn}) {
     assert(_needToInferReturnType);
-    // ignore: unnecessary_null_comparison
-    assert(hasImplicitReturn != null);
     DartType? actualReturnedType;
     DartType inferredReturnType;
     if (inferrer.isNonNullableByDefault) {
@@ -737,8 +733,6 @@ class _AsyncClosureContext implements ClosureContext {
   DartType inferReturnType(InferenceVisitorBase inferrer,
       {required bool hasImplicitReturn}) {
     assert(_needToInferReturnType);
-    // ignore: unnecessary_null_comparison
-    assert(hasImplicitReturn != null);
     DartType? inferredType;
 
     if (inferrer.isNonNullableByDefault) {
@@ -973,8 +967,6 @@ class _SyncStarClosureContext implements ClosureContext {
   DartType inferReturnType(InferenceVisitorBase inferrer,
       {required bool hasImplicitReturn}) {
     assert(_needToInferReturnType);
-    // ignore: unnecessary_null_comparison
-    assert(hasImplicitReturn != null);
     DartType? inferredElementType;
     if (_yieldElementTypes!.isNotEmpty) {
       // Use the types seen from the explicit return statements.
@@ -1109,8 +1101,6 @@ class _AsyncStarClosureContext implements ClosureContext {
   DartType inferReturnType(InferenceVisitorBase inferrer,
       {required bool hasImplicitReturn}) {
     assert(_needToInferReturnType);
-    // ignore: unnecessary_null_comparison
-    assert(hasImplicitReturn != null);
     DartType? inferredElementType;
     if (_yieldElementTypes!.isNotEmpty) {
       // Use the types seen from the explicit return statements.

pkg/front_end/lib/src/fasta/type_inference/inference_results.dart

@@ -222,9 +222,7 @@ class WrapInProblemInferenceResult implements InvocationInferenceResult {
 
   WrapInProblemInferenceResult(this.inferredType, this.functionType,
       this.message, this.fileOffset, this.length, this.helper,
-      {required this.isInapplicable, required this.hoistedArguments})
+      {required this.isInapplicable, required this.hoistedArguments});
-      // ignore: unnecessary_null_comparison
-      : assert(isInapplicable != null);
 
   @override
   Expression applyResult(Expression expression) {
@@ -345,9 +343,7 @@ class ExpressionInferenceResult {
 
   ExpressionInferenceResult(this.inferredType, this.expression,
       {this.postCoercionType = null})
-      // ignore: unnecessary_null_comparison
+      : assert(isKnown(inferredType));
-      : assert(expression != null),
-        assert(isKnown(inferredType));
 
   /// The guards used for null-aware access if the expression is part of a
   /// null-shorting.
@@ -377,13 +373,7 @@ class NullAwareGuard {
   final InferenceVisitorBase _inferrer;
 
   NullAwareGuard(
-      this._nullAwareVariable, this._nullAwareFileOffset, this._inferrer)
+      this._nullAwareVariable, this._nullAwareFileOffset, this._inferrer) {
-      // ignore: unnecessary_null_comparison
-      : assert(_nullAwareVariable != null),
-        // ignore: unnecessary_null_comparison
-        assert(_nullAwareFileOffset != null),
-        // ignore: unnecessary_null_comparison
-        assert(_inferrer != null) {
     // Ensure the initializer of [_nullAwareVariable] is promoted to
     // non-nullable.
     _inferrer.flowAnalysis.nullAwareAccess_rightBegin(
@@ -447,9 +437,7 @@ class NullAwareExpressionInferenceResult implements ExpressionInferenceResult {
 
   NullAwareExpressionInferenceResult(this.inferredType,
       this.nullAwareActionType, this.nullAwareGuards, this.nullAwareAction)
-      : assert(nullAwareGuards.isNotEmpty),
+      : assert(nullAwareGuards.isNotEmpty);
-        // ignore: unnecessary_null_comparison
-        assert(nullAwareAction != null);
 
   @override
   Expression get expression {

pkg/front_end/lib/src/fasta/type_inference/inference_visitor.dart

@@ -246,11 +246,6 @@ class InferenceVisitorImpl extends InferenceVisitorBase
       {bool isVoidAllowed = false, bool forEffect = false}) {
     registerIfUnreachableForTesting(expression);
 
-    // `null` should never be used as the type context.  An instance of
-    // `UnknownType` should be used instead.
-    // ignore: unnecessary_null_comparison
-    assert(typeContext != null);
-
     ExpressionInferenceResult result;
     if (expression is ExpressionJudgment) {
       result = expression.acceptInference(this, typeContext);
@@ -260,9 +255,6 @@ class InferenceVisitorImpl extends InferenceVisitorBase
       result = expression.accept1(this, typeContext);
     }
     DartType inferredType = result.inferredType;
-    // ignore: unnecessary_null_comparison
-    assert(inferredType != null,
-        "No type inferred for $expression (${expression.runtimeType}).");
     if (inferredType is VoidType && !isVoidAllowed) {
       if (expression.parent is! ArgumentsImpl) {
         helper.addProblem(
@@ -943,15 +935,11 @@ class InferenceVisitorImpl extends InferenceVisitorBase
 
   BlockExpression _createBlockExpression(
       int fileOffset, Block body, Expression value) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     assert(fileOffset != TreeNode.noOffset);
     return new BlockExpression(body, value)..fileOffset = fileOffset;
   }
 
   ExpressionStatement _createExpressionStatement(Expression expression) {
-    // ignore: unnecessary_null_comparison
-    assert(expression != null);
     assert(expression.fileOffset != TreeNode.noOffset);
     return new ExpressionStatement(expression)
       ..fileOffset = expression.fileOffset;
@@ -1019,21 +1007,16 @@ class InferenceVisitorImpl extends InferenceVisitorBase
 
   ExpressionInferenceResult visitExtensionTearOff(
       ExtensionTearOff node, DartType typeContext) {
-    // ignore: unnecessary_null_comparison
+    FunctionType calleeType =
-    FunctionType calleeType = node.target != null
+        node.target.function.computeFunctionType(libraryBuilder.nonNullable);
-        ? node.target.function.computeFunctionType(libraryBuilder.nonNullable)
-        : new FunctionType([], const DynamicType(), libraryBuilder.nonNullable);
     TypeArgumentsInfo typeArgumentsInfo = getTypeArgumentsInfo(node.arguments);
     InvocationInferenceResult result = inferInvocation(this, typeContext,
         node.fileOffset, calleeType, node.arguments as ArgumentsImpl,
         staticTarget: node.target);
     StaticInvocation replacement =
         new StaticInvocation(node.target, node.arguments);
-    // ignore: unnecessary_null_comparison
+    libraryBuilder.checkBoundsInStaticInvocation(
-    if (node.target != null) {
+        replacement, typeSchemaEnvironment, helper.uri, typeArgumentsInfo);
-      libraryBuilder.checkBoundsInStaticInvocation(
-          replacement, typeSchemaEnvironment, helper.uri, typeArgumentsInfo);
-    }
     return instantiateTearOff(
         result.inferredType, typeContext, result.applyResult(replacement));
   }
@@ -1550,9 +1533,6 @@ class InferenceVisitorImpl extends InferenceVisitorBase
       Statement? expressionEffects,
       {bool isAsync = false,
       required bool hasProblem}) {
-    // ignore: unnecessary_null_comparison
-    assert(hasProblem != null);
-
     ForInVariable forInVariable =
         computeForInVariable(syntheticAssignment, hasProblem);
     DartType elementType = forInVariable.computeElementType(this);
@@ -3545,8 +3525,6 @@ class InferenceVisitorImpl extends InferenceVisitorBase
   }
 
   VariableDeclaration _createVariable(Expression expression, DartType type) {
-    // ignore: unnecessary_null_comparison
-    assert(expression != null);
     assert(expression.fileOffset != TreeNode.noOffset);
     return new VariableDeclaration.forValue(expression, type: type)
       ..fileOffset = expression.fileOffset;
@@ -3559,15 +3537,11 @@ class InferenceVisitorImpl extends InferenceVisitorBase
   }
 
   VariableGet _createVariableGet(VariableDeclaration variable) {
-    // ignore: unnecessary_null_comparison
-    assert(variable != null);
     assert(variable.fileOffset != TreeNode.noOffset);
     return new VariableGet(variable)..fileOffset = variable.fileOffset;
   }
 
   VariableGet _createNullCheckedVariableGet(VariableDeclaration variable) {
-    // ignore: unnecessary_null_comparison
-    assert(variable != null);
     assert(variable.fileOffset != TreeNode.noOffset);
     DartType promotedType =
         variable.type.withDeclaredNullability(libraryBuilder.nonNullable);
@@ -3581,8 +3555,6 @@ class InferenceVisitorImpl extends InferenceVisitorBase
   MapLiteral _createMapLiteral(int fileOffset, DartType keyType,
       DartType valueType, List<MapLiteralEntry> entries,
       {bool isConst = false}) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     assert(fileOffset != TreeNode.noOffset);
     return new MapLiteral(entries,
         keyType: keyType, valueType: valueType, isConst: isConst)
@@ -3592,8 +3564,6 @@ class InferenceVisitorImpl extends InferenceVisitorBase
   ListLiteral _createListLiteral(
       int fileOffset, DartType elementType, List<Expression> elements,
       {bool isConst = false}) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     assert(fileOffset != TreeNode.noOffset);
     return new ListLiteral(elements,
         typeArgument: elementType, isConst: isConst)
@@ -3603,8 +3573,6 @@ class InferenceVisitorImpl extends InferenceVisitorBase
   SetLiteral _createSetLiteral(
       int fileOffset, DartType elementType, List<Expression> elements,
       {bool isConst = false}) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     assert(fileOffset != TreeNode.noOffset);
     return new SetLiteral(elements, typeArgument: elementType, isConst: isConst)
       ..fileOffset = fileOffset;
@@ -3613,10 +3581,6 @@ class InferenceVisitorImpl extends InferenceVisitorBase
   Expression _createAdd(
       Expression receiver, InterfaceType receiverType, Expression argument,
       {required bool isSet}) {
-    // ignore: unnecessary_null_comparison
-    assert(receiver != null);
-    // ignore: unnecessary_null_comparison
-    assert(argument != null);
     assert(argument.fileOffset != TreeNode.noOffset,
         "No fileOffset on ${argument}.");
     DartType functionType = Substitution.fromInterfaceType(receiverType)
@@ -3635,10 +3599,6 @@ class InferenceVisitorImpl extends InferenceVisitorBase
 
   Expression _createAddAll(Expression receiver, InterfaceType receiverType,
       Expression argument, bool isSet) {
-    // ignore: unnecessary_null_comparison
-    assert(receiver != null);
-    // ignore: unnecessary_null_comparison
-    assert(argument != null);
     assert(argument.fileOffset != TreeNode.noOffset,
         "No fileOffset on ${argument}.");
     DartType functionType = Substitution.fromInterfaceType(receiverType)
@@ -3658,10 +3618,6 @@ class InferenceVisitorImpl extends InferenceVisitorBase
 
   Expression _createMapAddAll(
       Expression receiver, InterfaceType receiverType, Expression argument) {
-    // ignore: unnecessary_null_comparison
-    assert(receiver != null);
-    // ignore: unnecessary_null_comparison
-    assert(argument != null);
     assert(argument.fileOffset != TreeNode.noOffset,
         "No fileOffset on ${argument}.");
     DartType functionType = Substitution.fromInterfaceType(receiverType)
@@ -3679,8 +3635,6 @@ class InferenceVisitorImpl extends InferenceVisitorBase
 
   Expression _createEqualsNull(Expression expression,
       {bool notEquals = false}) {
-    // ignore: unnecessary_null_comparison
-    assert(expression != null);
     assert(expression.fileOffset != TreeNode.noOffset);
     Expression check = new EqualsNull(expression)
       ..fileOffset = expression.fileOffset;
@@ -3692,8 +3646,6 @@ class InferenceVisitorImpl extends InferenceVisitorBase
 
   Expression _createIndexSet(int fileOffset, Expression receiver,
       InterfaceType receiverType, Expression key, Expression value) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     assert(fileOffset != TreeNode.noOffset);
     DartType functionType = Substitution.fromInterfaceType(receiverType)
         .substituteType(engine.mapPutFunctionType);
@@ -3710,8 +3662,6 @@ class InferenceVisitorImpl extends InferenceVisitorBase
 
   AsExpression _createImplicitAs(
       int fileOffset, Expression expression, DartType type) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     assert(fileOffset != TreeNode.noOffset);
     return new AsExpression(expression, type)
       ..isTypeError = true
@@ -3721,8 +3671,6 @@ class InferenceVisitorImpl extends InferenceVisitorBase
 
   IfStatement _createIf(int fileOffset, Expression condition, Statement then,
       [Statement? otherwise]) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     assert(fileOffset != TreeNode.noOffset);
     return new IfStatement(condition, then, otherwise)..fileOffset = fileOffset;
   }
@@ -3730,8 +3678,6 @@ class InferenceVisitorImpl extends InferenceVisitorBase
   IfCaseStatement _createIfCase(int fileOffset, Expression condition,
       DartType matchedValueType, PatternGuard patternGuard, Statement then,
       [Statement? otherwise]) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     assert(fileOffset != TreeNode.noOffset);
     return new IfCaseStatement(condition, patternGuard, then, otherwise)
       ..matchedValueType = matchedValueType
@@ -3740,8 +3686,6 @@ class InferenceVisitorImpl extends InferenceVisitorBase
 
   Expression _createGetKey(
       int fileOffset, Expression receiver, InterfaceType entryType) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     assert(fileOffset != TreeNode.noOffset);
     DartType resultType = Substitution.fromInterfaceType(entryType)
         .substituteType(engine.mapEntryKey.type);
@@ -3753,8 +3697,6 @@ class InferenceVisitorImpl extends InferenceVisitorBase
 
   Expression _createGetValue(
       int fileOffset, Expression receiver, InterfaceType entryType) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     assert(fileOffset != TreeNode.noOffset);
     DartType resultType = Substitution.fromInterfaceType(entryType)
         .substituteType(engine.mapEntryValue.type);
@@ -3766,8 +3708,6 @@ class InferenceVisitorImpl extends InferenceVisitorBase
 
   Expression _createGetEntries(
       int fileOffset, Expression receiver, InterfaceType mapType) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     assert(fileOffset != TreeNode.noOffset);
     DartType resultType = Substitution.fromInterfaceType(mapType)
         .substituteType(engine.mapEntries.getterType);
@@ -3783,8 +3723,6 @@ class InferenceVisitorImpl extends InferenceVisitorBase
       Expression? condition,
       List<Expression> updates,
       Statement body) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     assert(fileOffset != TreeNode.noOffset);
     return new ForStatement(variables, condition, updates, body)
       ..fileOffset = fileOffset;
@@ -3793,8 +3731,6 @@ class InferenceVisitorImpl extends InferenceVisitorBase
   ForInStatement _createForInStatement(int fileOffset,
       VariableDeclaration variable, Expression iterable, Statement body,
       {bool isAsync = false}) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     assert(fileOffset != TreeNode.noOffset);
     return new ForInStatement(variable, iterable, body, isAsync: isAsync)
       ..fileOffset = fileOffset;
@@ -3819,8 +3755,6 @@ class InferenceVisitorImpl extends InferenceVisitorBase
       Expression then,
       Expression otherwise,
       DartType type) {
-    // ignore: unnecessary_null_comparison
-    assert(fileOffset != null);
     assert(fileOffset != TreeNode.noOffset);
     return new ConditionalExpression(condition, then, otherwise, type)
       ..fileOffset = fileOffset;
@@ -6023,8 +5957,6 @@ class InferenceVisitorImpl extends InferenceVisitorBase
   ExpressionInferenceResult _computeEqualsExpression(
       int fileOffset, Expression left, DartType leftType, Expression right,
       {required bool isNot}) {
-    // ignore: unnecessary_null_comparison
-    assert(isNot != null);
     ExpressionInfo<DartType>? equalityInfo =
         flowAnalysis.equalityOperand_end(left, leftType);
 
@@ -6693,8 +6625,6 @@ class InferenceVisitorImpl extends InferenceVisitorBase
       {required bool isThisReceiver,
       ObjectAccessTarget? readTarget,
       Expression? propertyGetNode}) {
-    // ignore: unnecessary_null_comparison
-    assert(isThisReceiver != null);
     Map<DartType, NonPromotionReason> Function() whyNotPromoted =
         flowAnalysis.whyNotPromoted(receiver);
 
@@ -6747,8 +6677,6 @@ class InferenceVisitorImpl extends InferenceVisitorBase
       Expression value,
       {required DartType valueType,
       required bool forEffect}) {
-    // ignore: unnecessary_null_comparison
-    assert(forEffect != null);
     Expression write;
     DartType writeType = valueType;
     switch (writeTarget.kind) {
@@ -8103,19 +8031,14 @@ class InferenceVisitorImpl extends InferenceVisitorBase
   @override
   ExpressionInferenceResult visitStaticInvocation(
       StaticInvocation node, DartType typeContext) {
-    // ignore: unnecessary_null_comparison
+    FunctionType calleeType =
-    FunctionType calleeType = node.target != null
+        node.target.function.computeFunctionType(libraryBuilder.nonNullable);
-        ? node.target.function.computeFunctionType(libraryBuilder.nonNullable)
-        : new FunctionType([], const DynamicType(), libraryBuilder.nonNullable);
     TypeArgumentsInfo typeArgumentsInfo = getTypeArgumentsInfo(node.arguments);
     InvocationInferenceResult result = inferInvocation(this, typeContext,
         node.fileOffset, calleeType, node.arguments as ArgumentsImpl,
         staticTarget: node.target);
-    // ignore: unnecessary_null_comparison
+    libraryBuilder.checkBoundsInStaticInvocation(
-    if (node.target != null) {
+        node, typeSchemaEnvironment, helper.uri, typeArgumentsInfo);
-      libraryBuilder.checkBoundsInStaticInvocation(
-          node, typeSchemaEnvironment, helper.uri, typeArgumentsInfo);
-    }
     return new ExpressionInferenceResult(
         result.inferredType, result.applyResult(node));
   }
@@ -9138,18 +9061,15 @@ class InferenceVisitorImpl extends InferenceVisitorBase
                 receiver.literal.length);
             return new ExpressionInferenceResult(const DynamicType(), error);
           }
-          // ignore: unnecessary_null_comparison
+          Expression? error = checkWebIntLiteralsErrorIfUnexact(
-          if (intValue != null) {
+              intValue, receiver.literal, receiver.fileOffset);
-            Expression? error = checkWebIntLiteralsErrorIfUnexact(
+          if (error != null) {
-                intValue, receiver.literal, receiver.fileOffset);
+            return new ExpressionInferenceResult(const DynamicType(), error);
-            if (error != null) {
-              return new ExpressionInferenceResult(const DynamicType(), error);
-            }
-            expressionResult = new ExpressionInferenceResult(
-                coreTypes.intRawType(libraryBuilder.nonNullable),
-                new IntLiteral(-intValue)
-                  ..fileOffset = node.expression.fileOffset);
           }
+          expressionResult = new ExpressionInferenceResult(
+              coreTypes.intRawType(libraryBuilder.nonNullable),
+              new IntLiteral(-intValue)
+                ..fileOffset = node.expression.fileOffset);
         }
       }
     }

pkg/front_end/lib/src/fasta/type_inference/inference_visitor_base.dart

@@ -237,23 +237,13 @@ abstract class InferenceVisitorBase implements InferenceVisitor {
 
   Expression createReachabilityError(
       int fileOffset, Message errorMessage, Message warningMessage) {
-    if (libraryBuilder.loader.target.context.options.warnOnReachabilityCheck &&
+    if (libraryBuilder.loader.target.context.options.warnOnReachabilityCheck) {
-        // ignore: unnecessary_null_comparison
-        warningMessage != null) {
       helper.addProblem(warningMessage, fileOffset, noLength);
     }
-    Arguments arguments;
+    Arguments arguments = new Arguments([
-    // ignore: unnecessary_null_comparison
+      new StringLiteral(errorMessage.problemMessage)..fileOffset = fileOffset
-    if (errorMessage != null) {
+    ])
-      arguments = new Arguments([
+      ..fileOffset = fileOffset;
-        new StringLiteral(errorMessage.problemMessage)..fileOffset = fileOffset
-      ])
-        ..fileOffset = fileOffset;
-    } else {
-      arguments = new Arguments([])..fileOffset = fileOffset;
-    }
-    // ignore: unnecessary_null_comparison
-    assert(coreTypes.reachabilityErrorConstructor != null);
     return new Throw(
         new ConstructorInvocation(
             coreTypes.reachabilityErrorConstructor, arguments)
@@ -461,9 +451,6 @@ abstract class InferenceVisitorBase implements InferenceVisitor {
       DartType? runtimeCheckedType,
       bool isVoidAllowed = false,
       bool coerceExpression = true}) {
-    // ignore: unnecessary_null_comparison
-    assert(contextType != null);
-
     fileOffset ??= inferenceResult.expression.fileOffset;
     contextType = computeGreatestClosure(contextType);
 
@@ -554,9 +541,6 @@ abstract class InferenceVisitorBase implements InferenceVisitor {
       Template<Message Function(DartType, DartType, DartType, DartType, bool)>?
           nullabilityPartErrorTemplate,
       Map<DartType, NonPromotionReason> Function()? whyNotPromoted}) {
-    // ignore: unnecessary_null_comparison
-    assert(contextType != null);
-
     // [errorTemplate], [nullabilityErrorTemplate], and
     // [nullabilityPartErrorTemplate] should be provided together.
     assert((errorTemplate == null) == (nullabilityErrorTemplate == null) &&
@@ -723,9 +707,6 @@ abstract class InferenceVisitorBase implements InferenceVisitor {
       Template<Message Function(DartType, DartType, DartType, DartType, bool)>?
           nullabilityPartErrorTemplate,
       Map<DartType, NonPromotionReason> Function()? whyNotPromoted}) {
-    // ignore: unnecessary_null_comparison
-    assert(contextType != null);
-
     if (coerceExpression) {
       ExpressionInferenceResult? coercionResult = coerceExpressionForAssignment(
           contextType, inferenceResult,
@@ -757,8 +738,6 @@ abstract class InferenceVisitorBase implements InferenceVisitor {
 
   Expression _wrapTearoffErrorExpression(Expression expression,
       DartType contextType, Template<Message Function(String)> template) {
-    // ignore: unnecessary_null_comparison
-    assert(template != null);
     Expression errorNode = new AsExpression(
         expression,
         // TODO(ahe): The outline phase doesn't correctly remove invalid
@@ -842,13 +821,6 @@ abstract class InferenceVisitorBase implements InferenceVisitor {
       required bool isVoidAllowed,
       required bool isExpressionTypePrecise,
       required bool coerceExpression}) {
-    // ignore: unnecessary_null_comparison
-    assert(isNonNullableByDefault != null);
-    // ignore: unnecessary_null_comparison
-    assert(isVoidAllowed != null);
-    // ignore: unnecessary_null_comparison
-    assert(isExpressionTypePrecise != null);
-
     // If an interface type is being assigned to a function type, see if we
     // should tear off `.call`.
     // TODO(paulberry): use resolveTypeParameter.  See findInterfaceMember.
@@ -1315,8 +1287,7 @@ abstract class InferenceVisitorBase implements InferenceVisitor {
       {required CallSiteAccessKind callSiteAccessKind,
       bool instrumented = true,
       bool includeExtensionMethods = false}) {
-    // ignore: unnecessary_null_comparison
+    assert(isKnown(receiverType));
-    assert(receiverType != null && isKnown(receiverType));
 
     bool isSetter = callSiteAccessKind == CallSiteAccessKind.setterInvocation;
 
@@ -1415,10 +1386,8 @@ abstract class InferenceVisitorBase implements InferenceVisitor {
       Name name,
       int fileOffset,
       Template<Message Function(String, DartType, bool)> errorTemplate) {
-    // ignore: unnecessary_null_comparison
+    assert(isKnown(receiverType));
-    assert(receiverType != null && isKnown(receiverType));
+    if (target.isMissing) {
-    // ignore: unnecessary_null_comparison
-    if (target.isMissing && errorTemplate != null) {
       int length = name.text.length;
       if (identical(name.text, callName.text) ||
           identical(name.text, unaryMinusName.text)) {
@@ -1806,8 +1775,7 @@ abstract class InferenceVisitorBase implements InferenceVisitor {
 
     TypeConstraintGatherer? gatherer;
     if (inferenceNeeded) {
-      // ignore: unnecessary_null_comparison
+      if (isConst) {
-      if (isConst && typeContext != null) {
         typeContext = new TypeVariableEliminator(
                 bottomType,
                 isNonNullableByDefault
@@ -2450,8 +2418,6 @@ abstract class InferenceVisitorBase implements InferenceVisitor {
       DartType typeContext,
       List<VariableDeclaration>? hoistedExpressions,
       {required bool isImplicitCall}) {
-    // ignore: unnecessary_null_comparison
-    assert(isImplicitCall != null);
     InvocationInferenceResult result = inferInvocation(
         visitor, typeContext, fileOffset, unknownFunction, arguments,
         hoistedExpressions: hoistedExpressions,
@@ -2476,8 +2442,6 @@ abstract class InferenceVisitorBase implements InferenceVisitor {
       DartType typeContext,
       List<VariableDeclaration>? hoistedExpressions,
       {required bool isImplicitCall}) {
-    // ignore: unnecessary_null_comparison
-    assert(isImplicitCall != null);
     InvocationInferenceResult result = inferInvocation(
         visitor, typeContext, fileOffset, unknownFunction, arguments,
         hoistedExpressions: hoistedExpressions,
@@ -2508,10 +2472,6 @@ abstract class InferenceVisitorBase implements InferenceVisitor {
       required bool isImplicitCall,
       Name? implicitInvocationPropertyName}) {
     assert(target.isMissing || target.isAmbiguous);
-    // ignore: unnecessary_null_comparison
-    assert(isExpressionInvocation != null);
-    // ignore: unnecessary_null_comparison
-    assert(isImplicitCall != null);
     Expression error = createMissingMethodInvocation(
         fileOffset, receiverType, name,
         receiver: receiver,
@@ -2544,8 +2504,6 @@ abstract class InferenceVisitorBase implements InferenceVisitor {
       DartType typeContext,
       List<VariableDeclaration>? hoistedExpressions,
       {required bool isImplicitCall}) {
-    // ignore: unnecessary_null_comparison
-    assert(isImplicitCall != null);
     assert(target.isExtensionMember ||
         target.isNullableExtensionMember ||
         target.isInlineClassMember ||
@@ -2659,8 +2617,6 @@ abstract class InferenceVisitorBase implements InferenceVisitor {
       DartType typeContext,
       List<VariableDeclaration>? hoistedExpressions,
       {required bool isImplicitCall}) {
-    // ignore: unnecessary_null_comparison
-    assert(isImplicitCall != null);
     assert(target.isCallFunction || target.isNullableCallFunction);
     FunctionType declaredFunctionType = target.getFunctionType(this);
     InvocationInferenceResult result = inferInvocation(
@@ -2765,12 +2721,6 @@ abstract class InferenceVisitorBase implements InferenceVisitor {
       {required bool isImplicitCall,
       required bool isSpecialCasedBinaryOperator,
       required bool isSpecialCasedTernaryOperator}) {
-    // ignore: unnecessary_null_comparison
-    assert(isImplicitCall != null);
-    // ignore: unnecessary_null_comparison
-    assert(isSpecialCasedBinaryOperator != null);
-    // ignore: unnecessary_null_comparison
-    assert(isSpecialCasedTernaryOperator != null);
     assert(target.isInstanceMember ||
         target.isObjectMember ||
         target.isNullableInstanceMember);
@@ -2932,8 +2882,6 @@ abstract class InferenceVisitorBase implements InferenceVisitor {
       DartType typeContext,
       List<VariableDeclaration>? hoistedExpressions,
       {required bool isExpressionInvocation}) {
-    // ignore: unnecessary_null_comparison
-    assert(isExpressionInvocation != null);
     assert(target.isInstanceMember ||
         target.isObjectMember ||
         target.isNullableInstanceMember);
@@ -3134,8 +3082,6 @@ abstract class InferenceVisitorBase implements InferenceVisitor {
       DartType typeContext,
       List<VariableDeclaration>? hoistedExpressions,
       {required bool isExpressionInvocation}) {
-    // ignore: unnecessary_null_comparison
-    assert(isExpressionInvocation != null);
     assert(target.isInstanceMember ||
         target.isObjectMember ||
         target.isNullableInstanceMember);
@@ -3310,11 +3256,6 @@ abstract class InferenceVisitorBase implements InferenceVisitor {
       Name? implicitInvocationPropertyName,
       List<VariableDeclaration>? hoistedExpressions,
       ObjectAccessTarget? target}) {
-    // ignore: unnecessary_null_comparison
-    assert(isExpressionInvocation != null);
-    // ignore: unnecessary_null_comparison
-    assert(isImplicitCall != null);
-
     target ??= findInterfaceMember(receiverType, name, fileOffset,
         instrumented: true,
         includeExtensionMethods: true,
@@ -3593,8 +3534,6 @@ abstract class InferenceVisitorBase implements InferenceVisitor {
   void checkBoundsInInstantiation(
       FunctionType functionType, List<DartType> arguments, int fileOffset,
       {required bool inferred}) {
-    // ignore: unnecessary_null_comparison
-    assert(inferred != null);
     // If [arguments] were inferred, check them.
 
     libraryBuilder.checkBoundsInInstantiation(
@@ -3805,8 +3744,6 @@ abstract class InferenceVisitorBase implements InferenceVisitor {
   MethodContravarianceCheckKind preCheckInvocationContravariance(
       DartType receiverType, ObjectAccessTarget target,
       {required bool isThisReceiver}) {
-    // ignore: unnecessary_null_comparison
-    assert(isThisReceiver != null);
     if (target.isInstanceMember || target.isObjectMember) {
       Member interfaceMember = target.member!;
       if (interfaceMember is Field ||
@@ -3888,10 +3825,6 @@ abstract class InferenceVisitorBase implements InferenceVisitor {
     }
     // TODO(paulberry): If [type] is a subtype of `Future`, should we just
     // return it unmodified?
-    // ignore: unnecessary_null_comparison
-    if (type == null) {
-      return coreTypes.futureRawType(libraryBuilder.nullable);
-    }
     return new FutureOrType(type, libraryBuilder.nonNullable);
   }
 
@@ -4117,8 +4050,6 @@ abstract class InferenceVisitorBase implements InferenceVisitor {
       required bool isExpressionInvocation,
       Name? implicitInvocationPropertyName,
       List<ExtensionAccessCandidate>? extensionAccessCandidates}) {
-    // ignore: unnecessary_null_comparison
-    assert(isExpressionInvocation != null);
     assert((receiver == null) == (arguments == null),
         "Receiver and arguments must be supplied together.");
     if (implicitInvocationPropertyName != null) {
@@ -4369,8 +4300,6 @@ abstract class InferenceVisitorBase implements InferenceVisitor {
       DartType receiverType, Name propertyName, Expression value,
       {required bool forEffect,
       List<ExtensionAccessCandidate>? extensionAccessCandidates}) {
-    // ignore: unnecessary_null_comparison
-    assert(forEffect != null);
     Template<Message Function(String, DartType, bool)> templateMissing;
     if (receiverType is ExtensionType) {
       templateMissing = templateUndefinedExtensionSetter;
@@ -4413,8 +4342,6 @@ abstract class InferenceVisitorBase implements InferenceVisitor {
       DartType receiverType, Expression index, Expression value,
       {required bool forEffect,
       List<ExtensionAccessCandidate>? extensionAccessCandidates}) {
-    // ignore: unnecessary_null_comparison
-    assert(forEffect != null);
     Template<Message Function(String, DartType, bool)> templateMissing;
     if (receiverType is ExtensionType) {
       templateMissing = templateUndefinedExtensionOperator;

pkg/front_end/lib/src/fasta/type_inference/object_access_target.dart

@@ -102,10 +102,6 @@ abstract class ObjectAccessTarget {
   factory ObjectAccessTarget.interfaceMember(
       DartType receiverType, Member member,
       {required bool isPotentiallyNullable}) {
-    // ignore: unnecessary_null_comparison
-    assert(member != null);
-    // ignore: unnecessary_null_comparison
-    assert(isPotentiallyNullable != null);
     return isPotentiallyNullable
         ? new InstanceAccessTarget.nullable(receiverType, member)
         : new InstanceAccessTarget.nonNullable(receiverType, member);
@@ -980,9 +976,7 @@ class ExtensionAccessCandidate {
 
   ExtensionAccessCandidate(this.memberBuilder, this.onType,
       this.onTypeInstantiateToBounds, this.target,
-      {required this.isPlatform})
+      {required this.isPlatform});
-      // ignore: unnecessary_null_comparison
-      : assert(isPlatform != null);
 
   bool? isMoreSpecificThan(TypeSchemaEnvironment typeSchemaEnvironment,
       ExtensionAccessCandidate other) {

pkg/front_end/lib/src/fasta/type_inference/type_constraint_gatherer.dart

@@ -151,8 +151,6 @@ abstract class TypeConstraintGatherer {
   /// type schema.
   bool _tryNullabilityAwareSubtypeMatch(DartType subtype, DartType supertype,
       {required bool constrainSupertype}) {
-    // ignore: unnecessary_null_comparison
-    assert(constrainSupertype != null);
     int baseConstraintCount = _protoConstraints.length;
     bool isMatch = _isNullabilityAwareSubtypeMatch(subtype, supertype,
         constrainSupertype: constrainSupertype);
@@ -327,13 +325,6 @@ abstract class TypeConstraintGatherer {
   /// [UnknownType], that is, to be a type schema.
   bool _isNullabilityAwareSubtypeMatch(DartType p, DartType q,
       {required bool constrainSupertype}) {
-    // ignore: unnecessary_null_comparison
-    assert(p != null);
-    // ignore: unnecessary_null_comparison
-    assert(q != null);
-    // ignore: unnecessary_null_comparison
-    assert(constrainSupertype != null);
-
     // If the type parameters being constrained occur in the supertype (that is,
     // [q]), the subtype (that is, [p]) is not allowed to contain them.  To
     // check that, the assert below uses the equivalence of the following: X ->
@@ -1066,18 +1057,15 @@ abstract class TypeConstraintGatherer {
       Member? callMember = getInterfaceMember(subtype.classNode, callName);
       if (callMember is Procedure && !callMember.isGetter) {
         DartType callType = callMember.getterType;
-        // ignore: unnecessary_null_comparison
+        callType =
-        if (callType != null) {
+            Substitution.fromInterfaceType(subtype).substituteType(callType);
-          callType =
+        // TODO(kmillikin): The subtype check will fail if the type of a
-              Substitution.fromInterfaceType(subtype).substituteType(callType);
+        // generic call method is a subtype of a non-generic function type.
-          // TODO(kmillikin): The subtype check will fail if the type of a
+        // For example, if `T call<T>(T arg)` is a subtype of `S->S` for some
-          // generic call method is a subtype of a non-generic function type.
+        // S.  However, explicitly tearing off that call method will work and
-          // For example, if `T call<T>(T arg)` is a subtype of `S->S` for some
+        // insert an explicit instantiation, so the implicit tear off should
-          // S.  However, explicitly tearing off that call method will work and
+        // work as well.  Figure out how to support this case.
-          // insert an explicit instantiation, so the implicit tear off should
+        return _isNullabilityObliviousSubtypeMatch(callType, supertype);
-          // work as well.  Figure out how to support this case.
-          return _isNullabilityObliviousSubtypeMatch(callType, supertype);
-        }
       }
     }
     return false;

pkg/front_end/lib/src/fasta/type_inference/type_demotion.dart

@@ -104,11 +104,7 @@ class _DemotionNullabilityNormalization extends ReplacementVisitor {
 
   const _DemotionNullabilityNormalization(
       {required this.demoteTypeVariables,
-      required this.forNonNullableByDefault})
+      required this.forNonNullableByDefault});
-      // ignore: unnecessary_null_comparison
-      : assert(demoteTypeVariables != null),
-        // ignore: unnecessary_null_comparison
-        assert(forNonNullableByDefault != null);
 
   @override
   Nullability? visitNullability(DartType node) {

pkg/front_end/lib/src/fasta/type_inference/type_inferrer.dart

@@ -142,9 +142,7 @@ class TypeInferrerImpl implements TypeInferrer {
       this.dataForTesting,
       FunctionType unknownFunctionNonNullable,
       FunctionType unknownFunctionLegacy)
-      // ignore: unnecessary_null_comparison
+      : unknownFunction = libraryBuilder.isNonNullableByDefault
-      : assert(libraryBuilder != null),
-        unknownFunction = libraryBuilder.isNonNullableByDefault
             ? unknownFunctionNonNullable
             : unknownFunctionLegacy,
         instrumentation = isTopLevel ? null : engine.instrumentation,
@@ -193,8 +191,6 @@ class TypeInferrerImpl implements TypeInferrer {
   @override
   InferredFunctionBody inferFunctionBody(InferenceHelper helper, int fileOffset,
       DartType returnType, AsyncMarker asyncMarker, Statement body) {
-    // ignore: unnecessary_null_comparison
-    assert(body != null);
     InferenceVisitorBase visitor = _createInferenceVisitor(helper);
     ClosureContext closureContext =
         new ClosureContext(visitor, asyncMarker, returnType, false);
@@ -292,8 +288,6 @@ class TypeInferrerImpl implements TypeInferrer {
       Expression initializer,
       DartType declaredType,
       bool hasDeclaredInitializer) {
-    // ignore: unnecessary_null_comparison
-    assert(declaredType != null);
     InferenceVisitorBase visitor = _createInferenceVisitor(helper);
     ExpressionInferenceResult result =
         visitor.inferExpression(initializer, declaredType);

pkg/front_end/lib/src/fasta/type_inference/type_schema_environment.dart

@@ -370,8 +370,6 @@ class TypeSchemaEnvironment extends HierarchyBasedTypeEnvironment
   bool isSpecialCasesBinaryForReceiverType(
       Procedure member, DartType receiverType,
       {required bool isNonNullableByDefault}) {
-    // ignore: unnecessary_null_comparison
-    assert(isNonNullableByDefault != null);
     if (!isNonNullableByDefault) {
       // TODO(paulberry): this matches what is defined in the spec.  It would be
       // nice if we could change kernel to match the spec and not have to

pkg/front_end/lib/src/fasta/uri_translator.dart

@@ -40,8 +40,6 @@ class UriTranslator {
 
   /// For a package uri, get the corresponding [Package].
   Package? getPackage(Uri uri) {
-    // ignore: unnecessary_null_comparison
-    if (packages == null) return null;
     if (!uri.isScheme("package")) return null;
     int firstSlash = uri.path.indexOf('/');
     if (firstSlash == -1) return null;

pkg/front_end/lib/src/fasta/util/parser_ast.dart

@@ -55,11 +55,6 @@ CompilationUnitEnd getAST(List<int> rawBytes,
     },
   );
   Token firstToken = scanner.tokenize();
-  // ignore: unnecessary_null_comparison
-  if (firstToken == null) {
-    throw "firstToken is null";
-  }
-
   ParserASTListener listener = new ParserASTListener();
   Parser parser;
   if (includeBody) {

pkg/front_end/lib/src/fasta/util/textual_outline.dart

@@ -450,12 +450,6 @@ String? textualOutline(
           ..originalPosition = originalPosition.value++);
   });
   Token firstToken = scanner.tokenize();
-  // ignore: unnecessary_null_comparison
-  if (firstToken == null) {
-    if (throwOnUnexpected) throw "firstToken is null";
-    return null;
-  }
-
   TextualOutlineListener listener = new TextualOutlineListener();
   ClassMemberParser classMemberParser = new ClassMemberParser(listener);
   classMemberParser.parseUnit(firstToken);
@@ -866,8 +860,7 @@ class TextualOutlineListener extends Listener {
 
   @override
   void endImport(Token importKeyword, Token? augmentToken, Token? semicolon) {
-    // ignore: unnecessary_null_comparison
+    if (semicolon != null) {
-    if (importKeyword != null && semicolon != null) {
       importExportsStartToChunk[importKeyword] = new _ImportChunk(
           importKeyword, semicolon, firstShowOrHide, _combinators);
     }

pkg/front_end/lib/src/testing/id_extractor.dart

@@ -83,8 +83,6 @@ abstract class DataExtractor<T> extends Visitor<void>
 
   void computeForMember(Member member) {
     MemberId id = computeMemberId(member);
-    // ignore: unnecessary_null_comparison
-    if (id == null) return;
     T? value = computeMemberValue(id, member);
     registerValue(member.fileUri, member.fileOffset, id, value, member);
   }

pkg/front_end/lib/src/testing/id_testing_helper.dart

@@ -413,8 +413,7 @@ Future<TestResult<T>> runTestForConfig<T>(MarkerOptions markerOptions,
 
     errorMap.forEach((Uri uri, Map<int, List<FormattedMessage>> map) {
       map.forEach((int offset, List<FormattedMessage> list) {
-        // ignore: unnecessary_null_comparison
+        if (offset < 0) {
-        if (offset == null || offset < 0) {
           // Position errors without offset in the begin of the file.
           offset = 0;
         }
@@ -578,8 +577,7 @@ void printMessageInLocation(
     if (source == null) {
       print('$uri@$offset: $message');
     } else {
-      // ignore: unnecessary_null_comparison
+      if (offset >= 1) {
-      if (offset != null && offset >= 1) {
         Location location = source.getLocation(uri, offset);
         print('$location: $message');
         if (!succinct) {

pkg/front_end/lib/widget_cache.dart

@@ -80,11 +80,7 @@ class WidgetCache {
     List<int> oldSource =
         lastGoodComponent.uriToSource[library.fileUri]!.source;
     List<int> newSource = partialComponent.uriToSource[library.fileUri]!.source;
-    // Library was added and does not exist in the old component.
+
-    // ignore: unnecessary_null_comparison
-    if (oldSource == null) {
-      return null;
-    }
     int newStartIndex = 0;
     int newEndIndex = newSource.length - 1;
     int oldStartIndex = 0;

pkg/front_end/test/crashing_test_case_minimizer_impl.dart

@@ -1106,12 +1106,6 @@ worlds:
         _isUriNnbd(uri) ? _scannerConfiguration : _scannerConfigurationNonNNBD,
         lineStarts);
 
-    // ignore: unnecessary_null_comparison
-    if (firstToken == null) {
-      print("Got null token from scanner for $uri");
-      return;
-    }
-
     int compileTry = 0;
     Token? token = firstToken;
     while (token is ErrorToken) {
@@ -1897,8 +1891,6 @@ worlds:
         }
       }
 
-      // ignore: unnecessary_null_comparison
-      if (foundLine == null) throw "Unexpected crash without stacktrace: $e";
       if (_expectedCrashLine == null) {
         print("Got '$foundLine'");
         _expectedCrashLine = foundLine;
@@ -2016,11 +2008,6 @@ worlds:
         nnbd ? _scannerConfiguration : _scannerConfigurationNonNNBD,
         lineStarts);
 
-    // ignore: unnecessary_null_comparison
-    if (firstToken == null) {
-      throw "Got null token from scanner";
-    }
-
     ParserTestListener parserTestListener = new ParserTestListener(false);
     Parser parser = new Parser(parserTestListener,
         useImplicitCreationExpression: useImplicitCreationExpressionInCfe);
@@ -2034,11 +2021,6 @@ worlds:
     Token firstToken = parser_suite.scanRawBytes(rawBytes,
         nnbd ? _scannerConfiguration : _scannerConfigurationNonNNBD, null);
 
-    // ignore: unnecessary_null_comparison
-    if (firstToken == null) {
-      return false;
-    }
-
     ParserErrorListener parserErrorListener = new ParserErrorListener();
     Parser parser = new Parser(parserErrorListener,
         useImplicitCreationExpression: useImplicitCreationExpressionInCfe);

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

@@ -278,16 +278,10 @@ class FolderOptions {
       // can be null
       this.overwriteCurrentSdkVersion,
       this.showOffsets = false})
-      // ignore: unnecessary_null_comparison
+      : assert(
-      : assert(nnbdAgnosticMode != null),
-        assert(
             // no this doesn't make any sense but left to underline
             // that this is allowed to be null!
-            defines != null || defines == null),
+            defines != null || defines == null);
-        // ignore: unnecessary_null_comparison
-        assert(noVerify != null),
-        // ignore: unnecessary_null_comparison
-        assert(target != null);
 
   Map<ExperimentalFlag, bool> computeExplicitExperimentalFlags(
       Map<ExperimentalFlag, bool> forcedExperimentalFlags) {
@@ -315,9 +309,7 @@ class TestOptions {
       {required this.nnbdMode,
       required this.allowedExperimentalFlags,
       required this.experimentEnabledVersion,
-      required this.experimentReleasedVersion})
+      required this.experimentReleasedVersion});
-      // ignore: unnecessary_null_comparison
-      : assert(linkDependencies != null);
 }
 
 class FastaContext extends ChainContext with MatchContext {
@@ -2335,10 +2327,7 @@ class Outline extends Step<TestDescription, ComponentResult, FastaContext> {
           backendTarget.performModularTransformations = true;
         }
         try {
-          // ignore: unnecessary_null_comparison
+          sourceTarget.runBuildTransformations();
-          if (sourceTarget.loader.coreTypes != null) {
-            sourceTarget.runBuildTransformations();
-          }
         } finally {
           if (backendTarget is TestTarget) {
             backendTarget.performModularTransformations = false;
@@ -2463,10 +2452,7 @@ class Transform extends Step<ComponentResult, ComponentResult, FastaContext> {
         backendTarget.performModularTransformations = true;
       }
       try {
-        // ignore: unnecessary_null_comparison
+        sourceTarget.runBuildTransformations();
-        if (sourceTarget.loader.coreTypes != null) {
-          sourceTarget.runBuildTransformations();
-        }
       } finally {
         if (backendTarget is TestTarget) {
           backendTarget.performModularTransformations = false;

pkg/front_end/test/incremental_suite.dart

@@ -1475,8 +1475,7 @@ class NewWorldTest {
         for (Uri uri in component!.uriToSource.keys) {
           // null is always there, so allow it implicitly.
           // Dart scheme uris too.
-          // ignore: unnecessary_null_comparison
+          if (uri.isScheme("org-dartlang-sdk")) continue;
-          if (uri == null || uri.isScheme("org-dartlang-sdk")) continue;
           if (!allowed.contains(uri)) {
             return new Result<TestData>(
                 data,

pkg/front_end/test/incremental_utils.dart

@@ -78,8 +78,6 @@ Future<void> throwOnInsufficientUriToSource(Component component,
   if (fileSystem != null) {
     uris = uriFinder.seenUris.toSet();
     for (Uri uri in uris) {
-      // ignore: unnecessary_null_comparison
-      if (uri == null) continue;
       if (!uri.isScheme("org-dartlang-test")) continue;
       // The file system doesn't have the sources for any modules.
       // For now assume that that is always what's going on.

pkg/front_end/test/parser_suite.dart

@@ -197,11 +197,6 @@ class ListenerStep extends Step<TestDescription, TestDescription, Context> {
     List<int> lineStarts = <int>[];
     Token firstToken = scanUri(uri, shortName, lineStarts: lineStarts);
 
-    // ignore: unnecessary_null_comparison
-    if (firstToken == null) {
-      return null;
-    }
-
     File f = new File.fromUri(uri);
     List<int> rawBytes = f.readAsBytesSync();
     Source source = new Source(lineStarts, rawBytes, uri, uri);
@@ -261,11 +256,6 @@ class IntertwinedStep extends Step<TestDescription, TestDescription, Context> {
     Token firstToken =
         scanUri(description.uri, description.shortName, lineStarts: lineStarts);
 
-    // ignore: unnecessary_null_comparison
-    if (firstToken == null) {
-      return Future.value(crash(description, StackTrace.current));
-    }
-
     File f = new File.fromUri(description.uri);
     List<int> rawBytes = f.readAsBytesSync();
     Source source =
@@ -301,11 +291,6 @@ class TokenStep extends Step<TestDescription, TestDescription, Context> {
     Token firstToken =
         scanUri(description.uri, description.shortName, lineStarts: lineStarts);
 
-    // ignore: unnecessary_null_comparison
-    if (firstToken == null) {
-      return Future.value(crash(description, StackTrace.current));
-    }
-
     StringBuffer beforeParser = tokenStreamToString(firstToken, lineStarts);
     StringBuffer beforeParserWithTypes =
         tokenStreamToString(firstToken, lineStarts, addTypes: true);

pkg/front_end/test/utils/kernel_chain.dart

@@ -210,9 +210,7 @@ class MatchExpectation
   /// be serialized, deserialized, and the textual representation of that is
   /// compared. It is still the original component that is returned though.
   const MatchExpectation(this.suffix,
-      {this.serializeFirst = false, required this.isLastMatchStep})
+      {this.serializeFirst = false, required this.isLastMatchStep});
-      // ignore: unnecessary_null_comparison
-      : assert(isLastMatchStep != null);
 
   @override
   String get name => "match expectations";

pkg/front_end/tool/_fasta/entry_points.dart

@@ -5,7 +5,7 @@
 library fasta.tool.entry_points;
 
 import 'dart:convert' show JsonEncoder, LineSplitter, jsonDecode, utf8;
-import 'dart:io' show File, Platform, exitCode, stderr, stdin, stdout;
+import 'dart:io' show File, Platform, stderr, stdin, stdout;
 import 'dart:typed_data' show Uint8List;
 
 import 'package:_fe_analyzer_shared/src/util/relativize.dart'
@@ -508,13 +508,6 @@ Future<void> compilePlatformInternal(CompilerContext c, Uri fullOutput,
 
   CompilerResult result =
       await generateKernelInternal(buildSummary: true, buildComponent: true);
-  // ignore: unnecessary_null_comparison
-  if (result == null) {
-    exitCode = 1;
-    // Note: an error should have been reported by now.
-    print('The platform .dill files were not created.');
-    return;
-  }
   new File.fromUri(outlineOutput).writeAsBytesSync(result.summary!);
   c.options.ticker.logMs("Wrote outline to ${outlineOutput.toFilePath()}");
 

pkg/front_end/tool/_fasta/generate_messages.dart

@@ -175,7 +175,6 @@ Template compileTemplate(String name, int? index, String? problemMessage,
   // `|` (verbatim) as they always contain a trailing newline that we don't
   // want.
   problemMessage = problemMessage.trimRight();
-  const String ignoreNotNull = "// ignore: unnecessary_null_comparison";
   var parameters = new Set<String>();
   var conversions = new Set<String>();
   var conversions2 = new Set<String>();
@@ -261,8 +260,7 @@ Template compileTemplate(String name, int? index, String? problemMessage,
 
       case "nameOKEmpty":
         parameters.add("String nameOKEmpty");
-        conversions.add("$ignoreNotNull\n"
+        conversions.add("if (nameOKEmpty.isEmpty) "
-            "if (nameOKEmpty == null || nameOKEmpty.isEmpty) "
             "nameOKEmpty = '(unnamed)';");
         arguments.add("'nameOKEmpty': nameOKEmpty");
         break;
@@ -306,8 +304,7 @@ Template compileTemplate(String name, int? index, String? problemMessage,
 
       case "stringOKEmpty":
         parameters.add("String stringOKEmpty");
-        conversions.add("$ignoreNotNull\n"
+        conversions.add("if (stringOKEmpty.isEmpty) "
-            "if (stringOKEmpty == null || stringOKEmpty.isEmpty) "
             "stringOKEmpty = '(empty)';");
         arguments.add("'$name': stringOKEmpty");
         break;
@@ -344,15 +341,11 @@ Template compileTemplate(String name, int? index, String? problemMessage,
 
       case "count":
         parameters.add("int count");
-        conversions.add(
-            "$ignoreNotNull\n" "if (count == null) throw 'No count provided';");
         arguments.add("'$name': count");
         break;
 
       case "count2":
         parameters.add("int count2");
-        conversions.add("$ignoreNotNull\n"
-            "if (count2 == null) throw 'No count provided';");
         arguments.add("'$name': count2");
         break;
 
@@ -367,24 +360,18 @@ Template compileTemplate(String name, int? index, String? problemMessage,
 
       case "num1":
         parameters.add("num _num1");
-        conversions.add("$ignoreNotNull\n"
-            "if (_num1 == null) throw 'No number provided';");
         conversions.add("String num1 = ${format('_num1')};");
         arguments.add("'$name': _num1");
         break;
 
       case "num2":
         parameters.add("num _num2");
-        conversions.add("$ignoreNotNull\n"
-            "if (_num2 == null) throw 'No number provided';");
         conversions.add("String num2 = ${format('_num2')};");
         arguments.add("'$name': _num2");
         break;
 
       case "num3":
         parameters.add("num _num3");
-        conversions.add("$ignoreNotNull\n"
-            "if (_num3 == null) throw 'No number provided';");
         conversions.add("String num3 = ${format('_num3')};");
         arguments.add("'$name': _num3");
         break;
@@ -428,10 +415,7 @@ Template compileTemplate(String name, int? index, String? problemMessage,
   }
 
   if (parameters.isEmpty && conversions.isEmpty && arguments.isEmpty) {
-    // ignore: unnecessary_null_comparison
+    codeArguments.add('problemMessage: r"""$problemMessage"""');
-    if (problemMessage != null) {
-      codeArguments.add('problemMessage: r"""$problemMessage"""');
-    }
     if (correctionMessage != null) {
       codeArguments.add('correctionMessage: r"""$correctionMessage"""');
     }
@@ -447,10 +431,7 @@ const MessageCode message$name =
   }
 
   List<String> templateArguments = <String>[];
-  // ignore: unnecessary_null_comparison
+  templateArguments.add('problemMessageTemplate: r"""$problemMessage"""');
-  if (problemMessage != null) {
-    templateArguments.add('problemMessageTemplate: r"""$problemMessage"""');
-  }
   if (correctionMessage != null) {
     templateArguments
         .add('correctionMessageTemplate: r"""$correctionMessage"""');

pkg/front_end/tool/fasta_perf.dart

@@ -155,8 +155,6 @@ Map<Uri, List<int>> scanReachableFiles(Uri entryUri) {
 void collectSources(Uri start, Map<Uri, List<int>> files) {
   void helper(Uri uri) {
     uri = uriResolver.translate(uri) ?? uri;
-    // ignore: unnecessary_null_comparison
-    if (uri == null) return;
     if (files.containsKey(uri)) return;
     var contents = readBytesFromFileSync(uri);
     files[uri] = contents;

pkg/front_end/tool/kernel_ast_file_rewriter.dart

@@ -188,10 +188,6 @@ void processField(
 
   Token beginToken = classFields.beginToken;
   Token endToken = classFields.endToken;
-  // ignore: unnecessary_null_comparison
-  assert(beginToken != null);
-  // ignore: unnecessary_null_comparison
-  assert(endToken != null);
 
   String frozenCheckCode =
       """if (frozen) throw "Trying to modify frozen node!";""";

pkg/frontend_server/lib/frontend_server.dart

@@ -736,8 +736,6 @@ class FrontendCompiler implements CompilerInterface {
   Future<void> writeJavaScriptBundle(KernelCompilationResults results,
       String filename, String fileSystemScheme, String moduleFormat,
       {required bool fullComponent}) async {
-    // ignore: unnecessary_null_comparison
-    assert(fullComponent != null);
     var packageConfig = await loadPackageConfigUri(
         _compilerOptions.packagesFileUri ??
             File('.dart_tool/package_config.json').absolute.uri);

pkg/kernel/lib/binary/ast_from_binary.dart

@@ -120,6 +120,11 @@ abstract class StringInterner {
   String internString(String string);
 }
 
+/// Helper used to trigger the read of a late variable in asserts.
+bool _lateIsInitialized(dynamic value) {
+  return true;
+}
+
 class BinaryBuilder {
   final List<VariableDeclaration> variableStack = <VariableDeclaration>[];
   final List<LabeledStatement> labelStack = <LabeledStatement>[];
@@ -945,8 +950,7 @@ class BinaryBuilder {
   /// if [readCoverage] is true, references are read and that the link table
   /// thus has to be read first.
   Map<Uri, Source> readUriToSource({required bool readCoverage}) {
-    // ignore: unnecessary_null_comparison
+    assert(!readCoverage || (readCoverage && _lateIsInitialized(_linkTable)));
-    assert(!readCoverage || (readCoverage && _linkTable != null));
 
     int length = readUint32();
 
@@ -1508,8 +1512,10 @@ class BinaryBuilder {
     }
 
     typeParameterStack.length = 0;
-    // ignore: unnecessary_null_comparison
+    assert(() {
-    assert(debugPath.removeLast() != null);
+      debugPath.removeLast();
+      return true;
+    }());
     node.name = name;
     node.fileUri = fileUri;
     node.annotations = annotations;

pkg/kernel/lib/binary/ast_to_binary.dart

@@ -955,15 +955,10 @@ class BinaryPrinter implements Visitor<void>, BinarySink {
   }
 
   void writeNonNullReference(Reference reference) {
-    // ignore: unnecessary_null_comparison
+    assert(reference.isConsistent, reference.getInconsistency());
-    if (reference == null) {
+    CanonicalName name = _ensureCanonicalName(reference);
-      throw new ArgumentError('Got null reference');
+    checkCanonicalName(name);
-    } else {
+    writeUInt30(name.index + 1);
-      assert(reference.isConsistent, reference.getInconsistency());
-      CanonicalName name = _ensureCanonicalName(reference);
-      checkCanonicalName(name);
-      writeUInt30(name.index + 1);
-    }
   }
 
   /// Returns the canonical name for [reference].
@@ -1046,14 +1041,8 @@ class BinaryPrinter implements Visitor<void>, BinarySink {
 
   void writeNonNullCanonicalNameReference(Reference reference) {
     CanonicalName name = _ensureCanonicalName(reference);
-    // ignore: unnecessary_null_comparison
+    checkCanonicalName(name);
-    if (name == null) {
+    writeUInt30(name.index + 1);
-      throw new ArgumentError(
-          'Expected a canonical name to be valid but was `null`.');
-    } else {
-      checkCanonicalName(name);
-      writeUInt30(name.index + 1);
-    }
   }
 
   void writeOffset(int offset) {
@@ -1068,11 +1057,6 @@ class BinaryPrinter implements Visitor<void>, BinarySink {
   }
 
   void writeClassReference(Class class_) {
-    // ignore: unnecessary_null_comparison
-    if (class_ == null) {
-      throw new ArgumentError(
-          'Expected a class reference to be valid but was `null`.');
-    }
     writeNonNullCanonicalNameReference(class_.reference);
   }
 

pkg/kernel/lib/canonical_name.dart

@@ -94,10 +94,6 @@ class CanonicalName {
   int index = -1;
 
   CanonicalName._(CanonicalName parent, this.name) : _parent = parent {
-    // ignore: unnecessary_null_comparison
-    assert(name != null);
-    // ignore: unnecessary_null_comparison
-    assert(parent != null);
     _nonRootTop = parent.isRoot ? this : parent._nonRootTop;
   }
 
@@ -215,10 +211,6 @@ class CanonicalName {
   }
 
   void bindTo(Reference target) {
-    // ignore: unnecessary_null_comparison
-    if (target == null) {
-      throw '$this cannot be bound to null';
-    }
     if (_reference == target) return;
     if (_reference != null) {
       StringBuffer sb = new StringBuffer();

pkg/kernel/lib/class_hierarchy.dart

@@ -1754,9 +1754,6 @@ class _ClassInfo {
       } else {
         canonical = type;
       }
-      // ignore: unnecessary_null_comparison
-      assert(canonical != null,
-          "No canonical instantiation computed for $cls in $classNode.");
       genericSuperType![cls] = canonical;
       genericSuperTypes![cls] = <Supertype>[type];
     } else {

pkg/kernel/lib/clone.dart

@@ -615,10 +615,7 @@ class CloneVisitorNotMembers implements TreeVisitor<TreeNode> {
   TypeParameter visitTypeParameter(TypeParameter node) {
     TypeParameter newNode = typeParams[node]!;
     newNode.bound = visitType(node.bound);
-    // ignore: unnecessary_null_comparison
+    newNode.defaultType = visitType(node.defaultType);
-    if (node.defaultType != null) {
-      newNode.defaultType = visitType(node.defaultType);
-    }
     return newNode
       ..annotations = cloneAnnotations && !node.annotations.isEmpty
           ? node.annotations.map(clone).toList()
@@ -1209,8 +1206,6 @@ class MixinApplicationCloner extends CloneVisitorWithMembers {
             cloneAnnotations: cloneAnnotations);
 
   Member? _findSuperMember(Name name, {required bool isSetter}) {
-    // ignore: unnecessary_null_comparison
-    assert(isSetter != null);
     Map<Name, Member> cache;
     if (isSetter) {
       cache = _setterMap ??= {};

pkg/kernel/lib/import_table.dart

@@ -80,11 +80,7 @@ class _ImportTableBuilder extends RecursiveVisitor {
     if (target == referenceLibrary) return; // Self-reference is special.
     if (target == null) return;
     Uri referenceUri = referenceLibrary.importUri;
-    Uri? targetUri = target.importUri;
+    Uri targetUri = target.importUri;
-    // ignore: unnecessary_null_comparison
-    if (targetUri == null) {
-      throw '$referenceUri cannot refer to library without an import URI';
-    }
     // To support using custom-uris in unit tests, we don't check directly
     // whether the scheme is 'file:', but instead we check that is not 'dart:'
     // or 'package:'.

pkg/kernel/lib/src/bounds_checks.dart

@@ -210,9 +210,6 @@ List<DartType> calculateBounds(
 List<DartType> calculateBoundsInternal(
     List<TypeParameter> typeParameters, Class objectClass,
     {required bool isNonNullableByDefault}) {
-  // ignore: unnecessary_null_comparison
-  assert(isNonNullableByDefault != null);
-
   List<DartType> bounds =
       new List<DartType>.filled(typeParameters.length, dummyDartType);
   for (int i = 0; i < typeParameters.length; i++) {
@@ -342,11 +339,6 @@ List<TypeArgumentIssue> findTypeArgumentIssues(DartType type,
     {required bool allowSuperBounded,
     required bool isNonNullableByDefault,
     required bool areGenericArgumentsAllowed}) {
-  // ignore: unnecessary_null_comparison
-  assert(isNonNullableByDefault != null);
-  // ignore: unnecessary_null_comparison
-  assert(areGenericArgumentsAllowed != null);
-
   List<TypeParameter> variables = const <TypeParameter>[];
   List<DartType> arguments = const <DartType>[];
   List<TypeArgumentIssue> typedefRhsResult = const <TypeArgumentIssue>[];
@@ -498,11 +490,6 @@ List<TypeArgumentIssue> findTypeArgumentIssuesForInvocation(
     DartType bottomType,
     {required bool isNonNullableByDefault,
     required bool areGenericArgumentsAllowed}) {
-  // ignore: unnecessary_null_comparison
-  assert(isNonNullableByDefault != null);
-  // ignore: unnecessary_null_comparison
-  assert(areGenericArgumentsAllowed != null);
-
   assert(arguments.length == parameters.length);
   assert(bottomType == const NeverType.nonNullable() || bottomType is NullType);
 
@@ -550,9 +537,6 @@ String getGenericTypeName(DartType type) {
 DartType? convertSuperBoundedToRegularBounded(
     TypeEnvironment typeEnvironment, DartType type,
     {int variance = Variance.covariant, required bool isNonNullableByDefault}) {
-  // ignore: unnecessary_null_comparison
-  assert(isNonNullableByDefault != null);
-
   return type.accept1(
       new _SuperBoundedTypeInverter(typeEnvironment,
           isNonNullableByDefault: isNonNullableByDefault),
@@ -565,11 +549,7 @@ class _SuperBoundedTypeInverter extends ReplacementVisitor {
   bool isOutermost = true;
 
   _SuperBoundedTypeInverter(this.typeEnvironment,
-      {required this.isNonNullableByDefault})
+      {required this.isNonNullableByDefault});
-      // ignore: unnecessary_null_comparison
-      : assert(typeEnvironment != null),
-        // ignore: unnecessary_null_comparison
-        assert(isNonNullableByDefault != null);
 
   bool flipTop(int variance) {
     return isNonNullableByDefault

pkg/kernel/lib/src/const_canonical_type.dart

@@ -53,9 +53,6 @@ class _ConstCanonicalTypeVisitor extends ReplacementVisitor {
 /// https://github.com/dart-lang/language/blob/master/accepted/future-releases/nnbd/feature-specification.md#constant-instances
 DartType? computeConstCanonicalType(DartType type, CoreTypes coreTypes,
     {required bool isNonNullableByDefault}) {
-  // ignore: unnecessary_null_comparison
-  assert(isNonNullableByDefault != null);
-
   return type.accept1(
       new _ConstCanonicalTypeVisitor(coreTypes,
           isNonNullableByDefault: isNonNullableByDefault),

pkg/kernel/lib/target/targets.dart

@@ -402,12 +402,6 @@ abstract class Target {
       {required bool hasInitializer,
       required bool isFinal,
       required bool isStatic}) {
-    // ignore: unnecessary_null_comparison
-    assert(hasInitializer != null);
-    // ignore: unnecessary_null_comparison
-    assert(isFinal != null);
-    // ignore: unnecessary_null_comparison
-    assert(isStatic != null);
     int mask = LateLowering.getFieldLowering(
         hasInitializer: hasInitializer, isFinal: isFinal, isStatic: isStatic);
     return enabledLateLowerings & mask != 0;
@@ -461,12 +455,6 @@ abstract class Target {
       {required bool hasInitializer,
       required bool isFinal,
       required bool isPotentiallyNullable}) {
-    // ignore: unnecessary_null_comparison
-    assert(hasInitializer != null);
-    // ignore: unnecessary_null_comparison
-    assert(isFinal != null);
-    // ignore: unnecessary_null_comparison
-    assert(isPotentiallyNullable != null);
     int mask = LateLowering.getLocalLowering(
         hasInitializer: hasInitializer,
         isFinal: isFinal,
@@ -656,12 +644,6 @@ class LateLowering {
       {required bool hasInitializer,
       required bool isFinal,
       required bool isPotentiallyNullable}) {
-    // ignore: unnecessary_null_comparison
-    assert(hasInitializer != null);
-    // ignore: unnecessary_null_comparison
-    assert(isFinal != null);
-    // ignore: unnecessary_null_comparison
-    assert(isPotentiallyNullable != null);
     if (hasInitializer) {
       if (isFinal) {
         if (isPotentiallyNullable) {
@@ -697,12 +679,6 @@ class LateLowering {
       {required bool hasInitializer,
       required bool isFinal,
       required bool isStatic}) {
-    // ignore: unnecessary_null_comparison
-    assert(hasInitializer != null);
-    // ignore: unnecessary_null_comparison
-    assert(isFinal != null);
-    // ignore: unnecessary_null_comparison
-    assert(isStatic != null);
     if (hasInitializer) {
       if (isFinal) {
         if (isStatic) {

pkg/kernel/lib/testing/type_parser_environment.dart

@@ -79,8 +79,6 @@ class Env {
   final bool isNonNullableByDefault;
 
   Env(String source, {required this.isNonNullableByDefault}) {
-    // ignore: unnecessary_null_comparison
-    assert(isNonNullableByDefault != null);
     Uri libraryUri = Uri.parse('memory:main.dart');
     Uri coreUri = Uri.parse("dart:core");
     TypeParserEnvironment coreEnvironment =
@@ -211,8 +209,7 @@ class TypeParserEnvironment {
   }
 
   ParameterEnvironment extendToParameterEnvironment(String typeParameters) {
-    // ignore: unnecessary_null_comparison
+    assert(typeParameters.isNotEmpty);
-    assert(typeParameters != null && typeParameters.isNotEmpty);
     return const _KernelFromParsedType().computeTypeParameterEnvironment(
         parseTypeVariables("<${typeParameters}>"), this);
   }

pkg/kernel/lib/text/ast_to_text.dart

@@ -191,7 +191,6 @@ String componentToString(Component node) {
 class NameSystem {
   final Namer<VariableDeclaration> variables =
       new NormalNamer<VariableDeclaration>('#t');
-  final Namer<Member> members = new NormalNamer<Member>('#m');
   final Namer<Class> classes = new NormalNamer<Class>('#class');
   final Namer<Extension> extensions = new NormalNamer<Extension>('#extension');
   final Namer<Library> libraries = new NormalNamer<Library>('#lib');
@@ -203,7 +202,6 @@ class NameSystem {
       new Disambiguator<Reference, CanonicalName>();
 
   String nameVariable(VariableDeclaration node) => variables.getName(node);
-  String nameMember(Member node) => members.getName(node);
   String nameClass(Class node) => classes.getName(node);
   String nameExtension(Extension node) => extensions.getName(node);
   String nameLibrary(Library node) => libraries.getName(node);
@@ -224,17 +222,13 @@ class NameSystem {
       if (name != null) {
         return abbreviateName(name);
       }
-      // ignore: unnecessary_null_comparison
+      String path = node.importUri.hasEmptyPath
-      if (node.importUri != null) {
+          ? '${node.importUri}'
-        String path = node.importUri.hasEmptyPath
+          : node.importUri.pathSegments.last;
-            ? '${node.importUri}'
+      if (path.endsWith('.dart')) {
-            : node.importUri.pathSegments.last;
+        path = path.substring(0, path.length - '.dart'.length);
-        if (path.endsWith('.dart')) {
-          path = path.substring(0, path.length - '.dart'.length);
-        }
-        return abbreviateName(path);
       }
-      return 'L';
+      return abbreviateName(path);
     });
   }
 
@@ -327,8 +321,6 @@ class Printer extends Visitor<void> with VisitorVoidMixin {
   }
 
   String getLibraryReference(Library node) {
-    // ignore: unnecessary_null_comparison
-    if (node == null) return '<No Library>';
     if (importTable != null && importTable?.getImportIndex(node) != -1) {
       return syntheticNames.nameLibraryPrefix(node);
     }
@@ -348,32 +340,24 @@ class Printer extends Visitor<void> with VisitorVoidMixin {
   }
 
   String getClassReference(Class node) {
-    // ignore: unnecessary_null_comparison
-    if (node == null) return '<No Class>';
     String name = getClassName(node);
     String library = getLibraryReference(node.enclosingLibrary);
     return '$library::$name';
   }
 
   String getExtensionReference(Extension node) {
-    // ignore: unnecessary_null_comparison
-    if (node == null) return '<No Extension>';
     String name = getExtensionName(node);
     String library = getLibraryReference(node.enclosingLibrary);
     return '$library::$name';
   }
 
   String getInlineClassReference(InlineClass node) {
-    // ignore: unnecessary_null_comparison
-    if (node == null) return '<No InlineClass>';
     String name = getInlineClassName(node);
     String library = getLibraryReference(node.enclosingLibrary);
     return '$library::$name';
   }
 
   String getTypedefReference(Typedef node) {
-    // ignore: unnecessary_null_comparison
-    if (node == null) return '<No Typedef>';
     String library = getLibraryReference(node.enclosingLibrary);
     return '$library::${node.name}';
   }
@@ -383,14 +367,10 @@ class Printer extends Visitor<void> with VisitorVoidMixin {
 
   Name getMemberName(Member node) {
     if (node.name.text == '') return emptyName;
-    // ignore: unnecessary_null_comparison
+    return node.name;
-    if (node.name != null) return node.name;
-    return new Name(syntheticNames.nameMember(node));
   }
 
   String getMemberReference(Member node) {
-    // ignore: unnecessary_null_comparison
-    if (node == null) return '<No Member>';
     String name = getMemberName(node).text;
     Class? enclosingClass = node.enclosingClass;
     if (enclosingClass != null) {
@@ -407,8 +387,6 @@ class Printer extends Visitor<void> with VisitorVoidMixin {
   }
 
   String getVariableReference(VariableDeclaration node) {
-    // ignore: unnecessary_null_comparison
-    if (node == null) return '<No VariableDeclaration>';
     return getVariableName(node);
   }
 
@@ -417,8 +395,6 @@ class Printer extends Visitor<void> with VisitorVoidMixin {
   }
 
   String getTypeParameterReference(TypeParameter node) {
-    // ignore: unnecessary_null_comparison
-    if (node == null) return '<No TypeParameter>';
     String name = getTypeParameterName(node);
     TreeNode? parent = node.parent;
     if (parent is FunctionNode && parent.parent is Member) {
@@ -587,11 +563,8 @@ class Printer extends Visitor<void> with VisitorVoidMixin {
       if (name != null) {
         writeWord(name);
       }
-      // ignore: unnecessary_null_comparison
+      writeSpaced('from');
-      if (library.importUri != null) {
+      writeWord('"${library.importUri}"');
-        writeSpaced('from');
-        writeWord('"${library.importUri}"');
-      }
       String prefix = syntheticNames.nameLibraryPrefix(library);
       writeSpaced('as');
       writeWord(prefix);
@@ -716,33 +689,16 @@ class Printer extends Visitor<void> with VisitorVoidMixin {
   }
 
   void writeType(DartType type) {
-    // ignore: unnecessary_null_comparison
+    type.accept(this);
-    if (type == null) {
-      write('<No DartType>');
-    } else {
-      type.accept(this);
-    }
-  }
-
-  void writeOptionalType(DartType type) {
-    // ignore: unnecessary_null_comparison
-    if (type != null) {
-      type.accept(this);
-    }
   }
 
   @override
   void visitSupertype(Supertype type) {
-    // ignore: unnecessary_null_comparison
+    writeClassReferenceFromReference(type.className);
-    if (type == null) {
+    if (type.typeArguments.isNotEmpty) {
-      write('<No Supertype>');
+      writeSymbol('<');
-    } else {
+      writeList(type.typeArguments, writeType);
-      writeClassReferenceFromReference(type.className);
+      writeSymbol('>');
-      if (type.typeArguments.isNotEmpty) {
-        writeSymbol('<');
-        writeList(type.typeArguments, writeType);
-        writeSymbol('>');
-      }
     }
   }
 
@@ -919,8 +875,6 @@ class Printer extends Visitor<void> with VisitorVoidMixin {
   }
 
   void writeReturnType(DartType type, String? annotation) {
-    // ignore: unnecessary_null_comparison
-    if (type == null) return;
     writeSpaced('→');
     writeAnnotatedType(type, annotation);
   }
@@ -976,8 +930,6 @@ class Printer extends Visitor<void> with VisitorVoidMixin {
   }
 
   String getClassReferenceFromReference(Reference reference) {
-    // ignore: unnecessary_null_comparison
-    if (reference == null) return '<No Class>';
     if (reference.node != null) return getClassReference(reference.asClass);
     if (reference.canonicalName != null) {
       return getCanonicalNameString(reference.canonicalName!);
@@ -990,8 +942,6 @@ class Printer extends Visitor<void> with VisitorVoidMixin {
   }
 
   String getExtensionReferenceFromReference(Reference reference) {
-    // ignore: unnecessary_null_comparison
-    if (reference == null) return '<No Extension>';
     if (reference.node != null) {
       return getExtensionReference(reference.asExtension);
     }
@@ -1006,8 +956,6 @@ class Printer extends Visitor<void> with VisitorVoidMixin {
   }
 
   String getInlineClassReferenceFromReference(Reference reference) {
-    // ignore: unnecessary_null_comparison
-    if (reference == null) return '<No Extension>';
     if (reference.node != null) {
       return getInlineClassReference(reference.asInlineClass);
     }
@@ -1932,12 +1880,9 @@ class Printer extends Visitor<void> with VisitorVoidMixin {
       writeWord('const');
       writeSpace();
     }
-    // ignore: unnecessary_null_comparison
+    writeSymbol('<');
-    if (node.typeArgument != null) {
+    writeType(node.typeArgument);
-      writeSymbol('<');
+    writeSymbol('>');
-      writeType(node.typeArgument);
-      writeSymbol('>');
-    }
     writeSymbol('[');
     writeList(node.expressions, writeNode);
     writeSymbol(']');
@@ -1949,12 +1894,9 @@ class Printer extends Visitor<void> with VisitorVoidMixin {
       writeWord('const');
       writeSpace();
     }
-    // ignore: unnecessary_null_comparison
+    writeSymbol('<');
-    if (node.typeArgument != null) {
+    writeType(node.typeArgument);
-      writeSymbol('<');
+    writeSymbol('>');
-      writeType(node.typeArgument);
-      writeSymbol('>');
-    }
     writeSymbol('{');
     writeList(node.expressions, writeNode);
     writeSymbol('}');
@@ -1966,12 +1908,9 @@ class Printer extends Visitor<void> with VisitorVoidMixin {
       writeWord('const');
       writeSpace();
     }
-    // ignore: unnecessary_null_comparison
+    writeSymbol('<');
-    if (node.keyType != null) {
+    writeList([node.keyType, node.valueType], writeType);
-      writeSymbol('<');
+    writeSymbol('>');
-      writeList([node.keyType, node.valueType], writeType);
-      writeSymbol('>');
-    }
     writeSymbol('{');
     writeList(node.entries, writeNode);
     writeSymbol('}');
@@ -2172,12 +2111,9 @@ class Printer extends Visitor<void> with VisitorVoidMixin {
   }
 
   void writeStaticType(DartType type) {
-    // ignore: unnecessary_null_comparison
+    writeSymbol('{');
-    if (type != null) {
+    writeType(type);
-      writeSymbol('{');
+    writeSymbol('}');
-      writeType(type);
-      writeSymbol('}');
-    }
   }
 
   @override
@@ -2533,12 +2469,9 @@ class Printer extends Visitor<void> with VisitorVoidMixin {
   @override
   void visitCatch(Catch node) {
     writeIndentation();
-    // ignore: unnecessary_null_comparison
+    writeWord('on');
-    if (node.guard != null) {
+    writeType(node.guard);
-      writeWord('on');
+    writeSpace();
-      writeType(node.guard);
-      writeSpace();
-    }
     writeWord('catch');
     writeSymbol('(');
     VariableDeclaration? exception = node.exception;
@@ -2590,13 +2523,7 @@ class Printer extends Visitor<void> with VisitorVoidMixin {
     writeAnnotationList(node.variable.annotations);
     writeIndentation();
     writeWord('function');
-    // ignore: unnecessary_null_comparison
+    writeFunction(node.function, name: getVariableName(node.variable));
-    if (node.function != null) {
-      writeFunction(node.function, name: getVariableName(node.variable));
-    } else {
-      writeWord(getVariableName(node.variable));
-      endLine('...;');
-    }
   }
 
   void writeVariableDeclaration(VariableDeclaration node,
@@ -2624,14 +2551,7 @@ class Printer extends Visitor<void> with VisitorVoidMixin {
         !node.hasDeclaredInitializer) {
       writeModifier(node.hasDeclaredInitializer, 'has-no-declared-initializer');
     }
-    // ignore: unnecessary_null_comparison
+    writeAnnotatedType(node.type, annotator?.annotateVariable(this, node));
-    if (node.type != null) {
-      writeAnnotatedType(node.type, annotator?.annotateVariable(this, node));
-    }
-    // ignore: unnecessary_null_comparison
-    if (useVarKeyword && !node.isFinal && !node.isConst && node.type == null) {
-      writeWord('var');
-    }
     writeWord(getVariableName(node));
     Expression? initializer = node.initializer;
     if (initializer != null) {

pkg/kernel/lib/transformations/track_widget_constructor_locations.dart

@@ -368,8 +368,7 @@ class WidgetCreatorTracker {
     bool foundLocationClass = false;
     for (Library library in libraries) {
       final Uri importUri = library.importUri;
-      // ignore: unnecessary_null_comparison
+      if (importUri.isScheme('package')) {
-      if (importUri != null && importUri.isScheme('package')) {
         if (importUri.path == 'flutter/src/widgets/framework.dart') {
           for (Class class_ in library.classes) {
             if (class_.name == 'Widget') {