[vm] Disable late field init for constructor initialized fields

Change-Id: Ibdab37839d07b77bf2c92a09f760f44b54d94bcb
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/138620
Reviewed-by: Alexander Markov <[email protected]>
Commit-Queue: Liam Appelbe <[email protected]>

Author: liamappelbe

runtime/vm/compiler/frontend/kernel_binary_flowgraph.cc

@@ -314,9 +314,11 @@ Fragment StreamingFlowGraphBuilder::BuildInitializers(
         field_helper.ReadUntilExcluding(FieldHelper::kInitializer);
         const Tag initializer_tag = ReadTag();
         if (class_field.is_late()) {
-          instructions +=
-              BuildLateFieldInitializer(Field::ZoneHandle(Z, class_field.raw()),
-                                        initializer_tag == kSomething);
+          if (!is_constructor_initialized) {
+            instructions += BuildLateFieldInitializer(
+                Field::ZoneHandle(Z, class_field.raw()),
+                initializer_tag == kSomething);
+          }
         } else if (initializer_tag == kSomething) {
           EnterScope(field_offset);
           // If this field is initialized in constructor then we can ignore the

tests/language/nnbd/syntax/late_modifier_non_final_field_test.dart

@@ -18,6 +18,11 @@ class A {
   late int? fieldWithNullInit = null;
   late int fieldWithNoInit;
   late int? nullableFieldWithNoInit;
+  late int? fieldWithOnlyCtorInit;
+  late int? fieldWithOnlyBothInitAndCtorInit = 123;
+  A()
+      : fieldWithOnlyCtorInit = null,
+        fieldWithOnlyBothInitAndCtorInit = null;
 }
 
 main() {
@@ -32,6 +37,8 @@ main() {
         () => a.fieldWithNoInit, (error) => error is LateInitializationError);
     Expect.throws(() => a.nullableFieldWithNoInit,
         (error) => error is LateInitializationError);
+    Expect.equals(null, a.fieldWithOnlyCtorInit);
+    Expect.equals(null, a.fieldWithOnlyBothInitAndCtorInit);
     Expect.equals(1, initCalls);
     Expect.equals(123, a.fieldWithInit);
     Expect.equals(123, a.fieldWithTrivialInit);
@@ -40,18 +47,24 @@ main() {
         () => a.fieldWithNoInit, (error) => error is LateInitializationError);
     Expect.throws(() => a.nullableFieldWithNoInit,
         (error) => error is LateInitializationError);
+    Expect.equals(null, a.fieldWithOnlyCtorInit);
+    Expect.equals(null, a.fieldWithOnlyBothInitAndCtorInit);
     Expect.equals(1, initCalls);
     a.fieldWithInit = 456;
     a.fieldWithTrivialInit = 456;
     a.fieldWithNullInit = 456;
     a.fieldWithNoInit = 456;
     a.nullableFieldWithNoInit = null;
+    a.fieldWithOnlyCtorInit = 456;
+    a.fieldWithOnlyBothInitAndCtorInit = 456;
     Expect.equals(1, initCalls);
     Expect.equals(456, a.fieldWithInit);
     Expect.equals(456, a.fieldWithTrivialInit);
     Expect.equals(456, a.fieldWithNullInit);
     Expect.equals(456, a.fieldWithNoInit);
     Expect.equals(null, a.nullableFieldWithNoInit);
+    Expect.equals(456, a.fieldWithOnlyCtorInit);
+    Expect.equals(456, a.fieldWithOnlyBothInitAndCtorInit);
     Expect.equals(1, initCalls);
     initCalls = 0;