[dart2js] Account for late sentinels in trivial inference results.

Fixes: #49599
Fixes: #55058
Fixes: #60115
Change-Id: I66673b6e467b54428e8d5ba317eec8aa3248645f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/258961
Reviewed-by: Nate Biggs <[email protected]>
Commit-Queue: Mayank Patke <[email protected]>

Author: fishythefish

pkg/compiler/lib/src/dump_info.dart

@@ -478,8 +478,8 @@ class ElementInfoCollector {
   GlobalTypeInferenceMemberResult _resultOfMember(MemberEntity e) =>
       _globalInferenceResults.resultOfMember(e);
 
-  AbstractValue _resultOfParameter(Local e) =>
-      _globalInferenceResults.resultOfParameter(e);
+  AbstractValue _resultOfParameter(Local e, MemberEntity? member) =>
+      _globalInferenceResults.resultOfParameter(e, member);
 
   FieldInfo? visitField(FieldEntity field) {
     AbstractValue inferredType = _resultOfMember(field).type;
@@ -695,7 +695,9 @@ class ElementInfoCollector {
       _globalInferenceResults.globalLocalsMap,
       function,
       (parameter) {
-        inferredParameterTypes.add('${_resultOfParameter(parameter)}');
+        inferredParameterTypes.add(
+          '${_resultOfParameter(parameter, function)}',
+        );
       },
     );
     int parameterIndex = 0;
@@ -1263,8 +1265,8 @@ class DumpInfoAnnotator {
   GlobalTypeInferenceMemberResult _resultOfMember(MemberEntity e) =>
       _globalInferenceResults.resultOfMember(e);
 
-  AbstractValue _resultOfParameter(Local e) =>
-      _globalInferenceResults.resultOfParameter(e);
+  AbstractValue _resultOfParameter(Local e, MemberEntity? member) =>
+      _globalInferenceResults.resultOfParameter(e, member);
 
   // TODO(markzipan): [parentName] is used for disambiguation, but this might
   // not always be valid. Check and validate later.
@@ -1511,7 +1513,9 @@ class DumpInfoAnnotator {
       _globalInferenceResults.globalLocalsMap,
       function,
       (parameter) {
-        inferredParameterTypes.add('${_resultOfParameter(parameter)}');
+        inferredParameterTypes.add(
+          '${_resultOfParameter(parameter, function)}',
+        );
       },
     );
     int parameterIndex = 0;

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

@@ -17,6 +17,7 @@ import '../js_model/element_map.dart';
 import '../js_model/elements.dart';
 import '../js_model/js_world.dart' show JClosedWorld;
 import '../js_model/locals.dart';
+import '../kernel/transformations/modular/late_lowering.dart' as late_lowering;
 import '../serialization/deferrable.dart';
 import '../serialization/serialization.dart';
 import '../universe/selector.dart' show Selector;
@@ -151,7 +152,7 @@ abstract class GlobalTypeInferenceResults {
 
   GlobalTypeInferenceMemberResult resultOfMember(MemberEntity member);
 
-  AbstractValue resultOfParameter(Local parameter);
+  AbstractValue resultOfParameter(Local parameter, MemberEntity? member);
 
   /// Returns the type of the result of applying [selector] to a receiver with
   /// the given [receiver] type.
@@ -408,7 +409,7 @@ class GlobalTypeInferenceResultsImpl implements GlobalTypeInferenceResults {
   }
 
   @override
-  AbstractValue resultOfParameter(Local parameter) {
+  AbstractValue resultOfParameter(Local parameter, _) {
     // TODO(sigmund,johnniwinther): Make it an error to query for results that
     // don't exist.
     /*assert(parameterResults.containsKey(parameter),
@@ -596,18 +597,26 @@ class GlobalTypeInferenceMemberResultImpl
 class TrivialGlobalTypeInferenceResults implements GlobalTypeInferenceResults {
   @override
   final JClosedWorld closedWorld;
-  final TrivialGlobalTypeInferenceMemberResult _trivialMemberResult;
-  final AbstractValue _trivialParameterResult;
+
+  final AbstractValue _trivialResult;
+  final AbstractValue _includingLateSentinelTrivialResult;
+
+  late final TrivialGlobalTypeInferenceMemberResult _trivialMemberResult =
+      TrivialGlobalTypeInferenceMemberResult(_trivialResult);
+  late final TrivialGlobalTypeInferenceMemberResult
+  _includingLateSentinelMemberResult = TrivialGlobalTypeInferenceMemberResult(
+    _includingLateSentinelTrivialResult,
+  );
+
   @override
   final InferredData inferredData = TrivialInferredData();
   @override
   final GlobalLocalsMap globalLocalsMap;
 
   TrivialGlobalTypeInferenceResults(this.closedWorld, this.globalLocalsMap)
-    : _trivialMemberResult = TrivialGlobalTypeInferenceMemberResult(
-        closedWorld.abstractValueDomain.dynamicType,
-      ),
-      _trivialParameterResult = closedWorld.abstractValueDomain.dynamicType;
+    : _trivialResult = closedWorld.abstractValueDomain.dynamicType,
+      _includingLateSentinelTrivialResult =
+          closedWorld.abstractValueDomain.internalTopType;
 
   @override
   void writeToDataSink(DataSinkWriter sink, JsToElementMap elementMap) {
@@ -616,16 +625,37 @@ class TrivialGlobalTypeInferenceResults implements GlobalTypeInferenceResults {
 
   @override
   AbstractValue resultTypeOfSelector(Selector selector, AbstractValue mask) {
-    return closedWorld.abstractValueDomain.dynamicType;
+    if (late_lowering.isNameOfLateInstanceBackingField(selector.name)) {
+      return _includingLateSentinelTrivialResult;
+    }
+    return _trivialResult;
   }
 
   @override
-  AbstractValue resultOfParameter(Local parameter) {
-    return _trivialParameterResult;
+  AbstractValue resultOfParameter(Local parameter, MemberEntity? member) {
+    if (member != null) {
+      if (closedWorld.commonElements.isIsSentinel(member) ||
+          closedWorld.commonElements.isIsJsSentinel(member)) {
+        return _includingLateSentinelTrivialResult;
+      }
+    }
+    return _trivialResult;
   }
 
   @override
   GlobalTypeInferenceMemberResult resultOfMember(MemberEntity member) {
+    if (member is FieldEntity) {
+      if (closedWorld.fieldAnalysis.getFieldData(member).isLateBackingField) {
+        return _includingLateSentinelMemberResult;
+      }
+    }
+    if (late_lowering.isNameOfLateInstanceBackingField(member.name)) {
+      return _includingLateSentinelMemberResult;
+    }
+    if (closedWorld.commonElements.isCreateSentinel(member) ||
+        closedWorld.commonElements.isCreateJsSentinel(member)) {
+      return _includingLateSentinelMemberResult;
+    }
     return _trivialMemberResult;
   }
 
@@ -641,15 +671,15 @@ class TrivialGlobalTypeInferenceResults implements GlobalTypeInferenceResults {
 
 class TrivialGlobalTypeInferenceMemberResult
     implements GlobalTypeInferenceMemberResult {
-  final AbstractValue dynamicType;
+  final AbstractValue topType;
 
-  TrivialGlobalTypeInferenceMemberResult(this.dynamicType);
+  TrivialGlobalTypeInferenceMemberResult(this.topType);
 
   @override
-  AbstractValue get type => dynamicType;
+  AbstractValue get type => topType;
 
   @override
-  AbstractValue get returnType => dynamicType;
+  AbstractValue get returnType => topType;
 
   @override
   bool get throwsAlways => false;

pkg/compiler/lib/src/js_model/element_map.dart

@@ -219,8 +219,12 @@ abstract class KernelToTypeInferenceMap {
   /// Returns the inferred type of [member].
   AbstractValue getInferredTypeOf(MemberEntity member);
 
-  /// Returns the inferred type of the [parameter].
-  AbstractValue getInferredTypeOfParameter(Local parameter);
+  /// Returns the inferred type of the [parameter]. [member] is the member that
+  /// declares [parameter], if any.
+  AbstractValue getInferredTypeOfParameter(
+    Local parameter,
+    MemberEntity? member,
+  );
 
   /// Returns the inferred result type of a dynamic [selector] access on the
   /// [receiver].

pkg/compiler/lib/src/js_model/js_strategy.dart

@@ -749,9 +749,13 @@ class KernelToTypeInferenceMapImpl implements KernelToTypeInferenceMap {
   }
 
   @override
-  AbstractValue getInferredTypeOfParameter(Local parameter) {
+  AbstractValue getInferredTypeOfParameter(
+    Local parameter,
+    MemberEntity? member,
+  ) {
     return AbstractValueFactory.inferredTypeForParameter(
       parameter,
+      member,
       _globalInferenceResults,
     );
   }

pkg/compiler/lib/src/kernel/transformations/modular/late_lowering.dart

@@ -31,12 +31,16 @@ bool _hasAssignableSuffix(String name) {
       name.endsWith(_lateAssignableInitializedSuffix);
 }
 
+bool isNameOfLateInstanceBackingField(String? name) {
+  return name != null &&
+      name.startsWith(_lateInstanceFieldPrefix) &&
+      (_hasFinalSuffix(name) || _hasAssignableSuffix(name));
+}
+
 bool isBackingFieldForLateInstanceField(Field field) {
   assert(!field.isStatic);
   if (!field.isInternalImplementation) return false;
-  final name = field.name.text;
-  return name.startsWith(_lateInstanceFieldPrefix) &&
-      (_hasFinalSuffix(name) || _hasAssignableSuffix(name));
+  return isNameOfLateInstanceBackingField(field.name.text);
 }
 
 bool isBackingFieldForLateFinalInstanceField(Field field) {

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

@@ -2342,6 +2342,7 @@ class KernelSsaGraphBuilder extends ir.VisitorDefault<void>
         }
         parameterMap[local] = _typeInferenceMap.getInferredTypeOfParameter(
           local,
+          member,
         );
       }
 

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

@@ -1055,11 +1055,9 @@ class SsaInstructionSimplifier extends HBaseVisitor<HInstruction>
 
     // TODO(ngeoffray): Also fold if it's a getter or variable.
     if (element.isFunction &&
-            // If we found out that the only target is an implicitly called
-            // `noSuchMethod` we just ignore it.
-            node
-            .selector
-            .applies(element)) {
+        // If we found out that the only target is an implicitly called
+        // `noSuchMethod` we just ignore it.
+        node.selector.applies(element)) {
       // `.isFunction` implies FunctionEntity, but not vice-versa.
       FunctionEntity method = element as FunctionEntity;
 

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

@@ -28,9 +28,10 @@ class AbstractValueFactory {
 
   static AbstractValue inferredTypeForParameter(
     Local element,
+    MemberEntity? member,
     GlobalTypeInferenceResults results,
   ) {
-    return results.resultOfParameter(element);
+    return results.resultOfParameter(element, member);
   }
 
   static AbstractValue inferredResultTypeForSelector(

pkg/compiler/test/codegen/expect_annotations_test.dart

@@ -58,7 +58,7 @@ runTest() async {
       results.globalLocalsMap,
       function,
       (Local parameter) {
-        AbstractValue type = results.resultOfParameter(parameter);
+        AbstractValue type = results.resultOfParameter(parameter, function);
         Expect.equals(
           expectedParameterType,
           simplify(type, commonMasks),

pkg/compiler/test/codegen/type_inference8_test.dart

@@ -73,7 +73,7 @@ Future runTest1() async {
   elementEnvironment.forEachParameterAsLocal(results.globalLocalsMap, bar, (
     barArg,
   ) {
-    AbstractValue barArgMask = results.resultOfParameter(barArg);
+    AbstractValue barArgMask = results.resultOfParameter(barArg, bar);
     Expect.equals(falseType, barArgMask);
   });
   String barCode = backendStrategy.getGeneratedCodeForTesting(bar)!;
@@ -130,7 +130,7 @@ Future runTest2() async {
   elementEnvironment.forEachParameterAsLocal(results.globalLocalsMap, bar, (
     barArg,
   ) {
-    AbstractValue barArgMask = results.resultOfParameter(barArg);
+    AbstractValue barArgMask = results.resultOfParameter(barArg, bar);
     // The argument to bar should have the same type as the return type of foo
     Expect.identical(commonMasks.boolType, barArgMask);
   });