[cfe] Don't replace concrete stubs with abstract methods in mixin transformation

Closes #46389
Closes #46390

Change-Id: If3446d08d0feaf8f778dc396bbed1ebb1c5c0bc7
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/212745
Reviewed-by: Dmitry Stefantsov <[email protected]>
Commit-Queue: Johnni Winther <[email protected]>

Author: johnniwinther

pkg/front_end/testcases/general/issue46389.dart.weak.transformed.expect

@@ -32,10 +32,14 @@ abstract class _C&A&B extends self::A implements self::B<core::num> /*isAnonymou
   synthetic constructor •() → self::_C&A&B
     : super self::A::•()
     ;
-  abstract set boz(generic-covariant-impl core::num x) → void;
-  abstract method foo(generic-covariant-impl core::num x) → core::num;
-  abstract method bar({required generic-covariant-impl core::num x = #C1}) → core::num;
-  abstract set baz(generic-covariant-impl core::num x) → void;
+  set boz(generic-covariant-impl core::num x) → void
+    return super.{self::A::boz} = x as core::int;
+  method foo(generic-covariant-impl core::num x) → core::num
+    return super.{self::A::foo}(x as core::int);
+  method bar({required generic-covariant-impl core::num x = #C1}) → core::num
+    return super.{self::A::bar}(x: x as core::int);
+  set baz(generic-covariant-impl core::num x) → void
+    return super.{self::A::baz} = x as core::int;
 }
 class C extends self::_C&A&B {
   synthetic constructor •() → self::C

pkg/front_end/testcases/general/issue46390.dart.weak.transformed.expect

@@ -21,7 +21,8 @@ abstract class _C&A&B extends self::A implements self::B<core::num> /*isAnonymou
   synthetic constructor •() → self::_C&A&B
     : super self::A::•()
     ;
-  abstract method foo(generic-covariant-impl core::num x) → core::num;
+  method foo(generic-covariant-impl core::num x) → core::num
+    return super.{self::A::foo}(x);
 }
 class C extends self::_C&A&B {
   synthetic constructor •() → self::C

pkg/front_end/testcases/nnbd_mixed/hierarchy/abstract_mixin.dart.weak.transformed.expect

@@ -30,7 +30,8 @@ class Class extends self::Super implements self::Interface, self::Mixin /*isElim
     ;
   abstract method extendedConcreteMixedInAbstractMethod() → void;
   method extendedConcreteMixedInConcreteMethod() → void {}
-  abstract method extendedConcreteMixedInAbstractImplementedMethod(covariant core::int i) → void;
+  method extendedConcreteMixedInAbstractImplementedMethod(covariant core::int i) → void
+    return super.{self::Super::extendedConcreteMixedInAbstractImplementedMethod}(i);
   method extendedConcreteMixedInConcreteImplementedMethod(covariant core::int i) → void {}
 }
 class Sub extends self::Class {

pkg/front_end/testcases/text_serialization.status

@@ -84,8 +84,6 @@ general/issue41210a: TypeCheckError
 general/issue41210b/issue41210.no_link: TypeCheckError
 general/issue41210b/issue41210: TypeCheckError
 general/issue44733: TypeCheckError
-general/issue46389: RuntimeError # issue 46389
-general/issue46390: RuntimeError # issue 46390
 general/issue_46886: RuntimeError
 general/micro: RuntimeError
 general/mixin_application_override: TypeCheckError

pkg/front_end/testcases/weak.status

@@ -88,8 +88,6 @@ general/issue41210a: TypeCheckError
 general/issue41210b/issue41210.no_link: TypeCheckError
 general/issue41210b/issue41210: TypeCheckError
 general/issue44733: TypeCheckError
-general/issue46389: RuntimeError # issue 46389
-general/issue46390: RuntimeError # issue 46390
 general/issue_46886: RuntimeError
 general/micro: RuntimeError
 general/mixin_application_override: ExpectationFileMismatch # Too many errors.

pkg/kernel/lib/transformations/mixin_full_resolution.dart

@@ -146,7 +146,9 @@ class MixinFullResolution {
         class_.addField(clone);
       }
       class_.procedures.clear();
-      class_.procedures..addAll(nonSetters.values)..addAll(setters.values);
+      class_.procedures
+        ..addAll(nonSetters.values)
+        ..addAll(setters.values);
     }
 
     // Existing procedures in the class should only be forwarding stubs.
@@ -190,6 +192,17 @@ class MixinFullResolution {
             // and don't add several procedures with the same name to the class.
             continue outer;
           }
+          if (procedure.isAbstract &&
+              (originalProcedure.stubKind ==
+                      ProcedureStubKind.ConcreteForwardingStub ||
+                  originalProcedure.stubKind ==
+                      ProcedureStubKind.ConcreteMixinStub)) {
+            // Don't replace concrete stubs with abstract methods.
+            originalProcedure.stubKind = ProcedureStubKind.Regular;
+            originalProcedure.stubTarget = null;
+            continue outer;
+          }
+
           originalIndex = i;
           break;
         }