[cfe] Add type checks on tearing off instance members

Dmitry Stefantsov · commit-bot@chromium.org · commit f77f8e587149 · 2021-08-06T15:19:35.000Z
Closes #46784. Bug: #46784 Change-Id: I7637618be0686bbffe6eb18a19049ec5da6059aa Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/208881 Reviewed-by: Johnni Winther <johnniwinther@google.com> Commit-Queue: Dmitry Stefantsov <dmitryas@google.com>
diff --git a/pkg/front_end/lib/src/fasta/kernel/inference_visitor.dart b/pkg/front_end/lib/src/fasta/kernel/inference_visitor.dart
@@ -4790,7 +4790,8 @@ class InferenceVisitor
             checkReturn =
                 TypeInferrerImpl.returnedTypeParametersOccurNonCovariantly(
                     interfaceMember.enclosingClass!,
-                    interfaceMember.function.returnType);
+                    interfaceMember.function
+                        .computeFunctionType(inferrer.library.nonNullable));
           } else if (interfaceMember is Field) {
             checkReturn =
                 TypeInferrerImpl.returnedTypeParametersOccurNonCovariantly(
diff --git a/pkg/front_end/testcases/general/bug33298.dart.weak.expect b/pkg/front_end/testcases/general/bug33298.dart.weak.expect
@@ -65,7 +65,7 @@ static method test() → dynamic {
   core::List<core::String*>* list1 = <core::String*>["a", "b", "c"].{core::Iterable::map}<core::String*>(a.{self::A::call}{(core::String*) →* core::String*}){((core::String*) →* core::String*) →* core::Iterable<core::String*>*}.{core::Iterable::toList}(){({growable: core::bool*}) →* core::List<core::String*>*};
   core::List<core::String*>* list2 = <core::String*>["a", "b", "c"].{core::Iterable::map}<core::String*>(let final self::A* #t1 = a in #t1 == null ?{(core::String*) →* core::String*} null : #t1.{self::A::call}{(core::String*) →* core::String*}){((core::String*) →* core::String*) →* core::Iterable<core::String*>*}.{core::Iterable::toList}(){({growable: core::bool*}) →* core::List<core::String*>*};
   self::B<core::String*>* b = new self::B::•<core::String*>();
-  core::List<core::String*>* list3 = <core::String*>["a", "b", "c"].{core::Iterable::map}<core::String*>(b.{self::B::call}{(core::String*) →* core::String*}){((core::String*) →* core::String*) →* core::Iterable<core::String*>*}.{core::Iterable::toList}(){({growable: core::bool*}) →* core::List<core::String*>*};
+  core::List<core::String*>* list3 = <core::String*>["a", "b", "c"].{core::Iterable::map}<core::String*>(b.{self::B::call}{(core::String*) →* core::String*} as{TypeError,CovarianceCheck} (core::String*) →* core::String*){((core::String*) →* core::String*) →* core::Iterable<core::String*>*}.{core::Iterable::toList}(){({growable: core::bool*}) →* core::List<core::String*>*};
   core::List<core::String*>* list4 = <core::String*>["a", "b", "c"].{core::Iterable::map}<core::String*>(let final self::B<core::String*>* #t2 = b in #t2 == null ?{(core::String*) →* core::String*} null : #t2.{self::B::call}{(core::String*) →* core::String*}){((core::String*) →* core::String*) →* core::Iterable<core::String*>*}.{core::Iterable::toList}(){({growable: core::bool*}) →* core::List<core::String*>*};
   self::C* c = new self::C::•();
   core::List<core::String*>* list5 = <core::String*>["a", "b", "c"].{core::Iterable::map}<core::String*>(c.{self::C::call}{<T extends core::Object* = dynamic>(T*) →* T*}<core::String*>){((core::String*) →* core::String*) →* core::Iterable<core::String*>*}.{core::Iterable::toList}(){({growable: core::bool*}) →* core::List<core::String*>*};
diff --git a/pkg/front_end/testcases/general/bug33298.dart.weak.transformed.expect b/pkg/front_end/testcases/general/bug33298.dart.weak.transformed.expect
@@ -65,7 +65,7 @@ static method test() → dynamic {
   core::List<core::String*>* list1 = core::_GrowableList::_literal3<core::String*>("a", "b", "c").{core::Iterable::map}<core::String*>(a.{self::A::call}{(core::String*) →* core::String*}){((core::String*) →* core::String*) →* core::Iterable<core::String*>*}.{core::Iterable::toList}(){({growable: core::bool*}) →* core::List<core::String*>*};
   core::List<core::String*>* list2 = core::_GrowableList::_literal3<core::String*>("a", "b", "c").{core::Iterable::map}<core::String*>(let final self::A* #t1 = a in #t1 == null ?{(core::String*) →* core::String*} null : #t1.{self::A::call}{(core::String*) →* core::String*}){((core::String*) →* core::String*) →* core::Iterable<core::String*>*}.{core::Iterable::toList}(){({growable: core::bool*}) →* core::List<core::String*>*};
   self::B<core::String*>* b = new self::B::•<core::String*>();
-  core::List<core::String*>* list3 = core::_GrowableList::_literal3<core::String*>("a", "b", "c").{core::Iterable::map}<core::String*>(b.{self::B::call}{(core::String*) →* core::String*}){((core::String*) →* core::String*) →* core::Iterable<core::String*>*}.{core::Iterable::toList}(){({growable: core::bool*}) →* core::List<core::String*>*};
+  core::List<core::String*>* list3 = core::_GrowableList::_literal3<core::String*>("a", "b", "c").{core::Iterable::map}<core::String*>(b.{self::B::call}{(core::String*) →* core::String*} as{TypeError,CovarianceCheck} (core::String*) →* core::String*){((core::String*) →* core::String*) →* core::Iterable<core::String*>*}.{core::Iterable::toList}(){({growable: core::bool*}) →* core::List<core::String*>*};
   core::List<core::String*>* list4 = core::_GrowableList::_literal3<core::String*>("a", "b", "c").{core::Iterable::map}<core::String*>(let final self::B<core::String*>* #t2 = b in #t2 == null ?{(core::String*) →* core::String*} null : #t2.{self::B::call}{(core::String*) →* core::String*}){((core::String*) →* core::String*) →* core::Iterable<core::String*>*}.{core::Iterable::toList}(){({growable: core::bool*}) →* core::List<core::String*>*};
   self::C* c = new self::C::•();
   core::List<core::String*>* list5 = core::_GrowableList::_literal3<core::String*>("a", "b", "c").{core::Iterable::map}<core::String*>(c.{self::C::call}{<T extends core::Object* = dynamic>(T*) →* T*}<core::String*>){((core::String*) →* core::String*) →* core::Iterable<core::String*>*}.{core::Iterable::toList}(){({growable: core::bool*}) →* core::List<core::String*>*};
diff --git a/pkg/front_end/testcases/general/method_tearoff_covariant_generic_type_check.dart b/pkg/front_end/testcases/general/method_tearoff_covariant_generic_type_check.dart
@@ -0,0 +1,23 @@
+// Copyright (c) 2021, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+class A<X extends num> {
+  void f<Y extends X>(Y y) {}
+}
+
+expectThrows(void Function() f) {
+  try {
+    f();
+  } catch (e) {
+    return;
+  }
+  throw "Expected an exception to be thrown!";
+}
+
+main() {
+  A<num> a = new A<int>();
+  expectThrows(() {
+    void Function<Y extends num>(Y) f = a.f;
+  });
+}
diff --git a/pkg/front_end/testcases/general/method_tearoff_covariant_generic_type_check.dart.textual_outline.expect b/pkg/front_end/testcases/general/method_tearoff_covariant_generic_type_check.dart.textual_outline.expect
@@ -0,0 +1,6 @@
+class A<X extends num> {
+  void f<Y extends X>(Y y) {}
+}
+
+expectThrows(void Function() f) {}
+main() {}
diff --git a/pkg/front_end/testcases/general/method_tearoff_covariant_generic_type_check.dart.textual_outline_modelled.expect b/pkg/front_end/testcases/general/method_tearoff_covariant_generic_type_check.dart.textual_outline_modelled.expect
@@ -0,0 +1,6 @@
+class A<X extends num> {
+  void f<Y extends X>(Y y) {}
+}
+
+expectThrows(void Function() f) {}
+main() {}
diff --git a/pkg/front_end/testcases/general/method_tearoff_covariant_generic_type_check.dart.weak.expect b/pkg/front_end/testcases/general/method_tearoff_covariant_generic_type_check.dart.weak.expect
@@ -0,0 +1,25 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "dart:core" as core;
+
+class A<X extends core::num> extends core::Object {
+  synthetic constructor •() → self::A<self::A::X>
+    : super core::Object::•()
+    ;
+  method f<generic-covariant-impl Y extends self::A::X>(self::A::f::Y y) → void {}
+}
+static method expectThrows(() → void f) → dynamic {
+  try {
+    f(){() → void};
+  }
+  on core::Object catch(final core::Object e) {
+    return;
+  }
+  throw "Expected an exception to be thrown!";
+}
+static method main() → dynamic {
+  self::A<core::num> a = new self::A::•<core::int>();
+  self::expectThrows(() → void {
+    <Y extends core::num>(Y) → void f = a.{self::A::f}{<generic-covariant-impl Y extends core::num>(Y) → void} as{TypeError,CovarianceCheck,ForNonNullableByDefault} <generic-covariant-impl Y extends core::num>(Y) → void;
+  });
+}
diff --git a/pkg/front_end/testcases/general/method_tearoff_covariant_generic_type_check.dart.weak.outline.expect b/pkg/front_end/testcases/general/method_tearoff_covariant_generic_type_check.dart.weak.outline.expect
@@ -0,0 +1,14 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "dart:core" as core;
+
+class A<X extends core::num> extends core::Object {
+  synthetic constructor •() → self::A<self::A::X>
+    ;
+  method f<generic-covariant-impl Y extends self::A::X>(self::A::f::Y y) → void
+    ;
+}
+static method expectThrows(() → void f) → dynamic
+  ;
+static method main() → dynamic
+  ;
diff --git a/pkg/front_end/testcases/general/method_tearoff_covariant_generic_type_check.dart.weak.transformed.expect b/pkg/front_end/testcases/general/method_tearoff_covariant_generic_type_check.dart.weak.transformed.expect
@@ -0,0 +1,25 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "dart:core" as core;
+
+class A<X extends core::num> extends core::Object {
+  synthetic constructor •() → self::A<self::A::X>
+    : super core::Object::•()
+    ;
+  method f<generic-covariant-impl Y extends self::A::X>(self::A::f::Y y) → void {}
+}
+static method expectThrows(() → void f) → dynamic {
+  try {
+    f(){() → void};
+  }
+  on core::Object catch(final core::Object e) {
+    return;
+  }
+  throw "Expected an exception to be thrown!";
+}
+static method main() → dynamic {
+  self::A<core::num> a = new self::A::•<core::int>();
+  self::expectThrows(() → void {
+    <Y extends core::num>(Y) → void f = a.{self::A::f}{<generic-covariant-impl Y extends core::num>(Y) → void} as{TypeError,CovarianceCheck,ForNonNullableByDefault} <generic-covariant-impl Y extends core::num>(Y) → void;
+  });
+}
diff --git a/pkg/front_end/testcases/runtime_checks/covariant_generic_parameter_tear_off.dart b/pkg/front_end/testcases/runtime_checks/covariant_generic_parameter_tear_off.dart
@@ -15,7 +15,7 @@ class C<T> {
 }
 
 F<num> g1(C<num> c) {
-  return c.f1;
+  return c. /*@ checkReturn=(num*) ->* void*/ f1;
 }
 
 void g2(C<int> c, Object x) {
@@ -24,7 +24,7 @@ void g2(C<int> c, Object x) {
 }
 
 G<List<num>, num> g3(C<num> c) {
-  return c.f2;
+  return c. /*@ checkReturn=(List<num*>*) ->* num**/ f2;
 }
 
 void test() {
diff --git a/pkg/front_end/testcases/runtime_checks/covariant_generic_parameter_tear_off.dart.weak.expect b/pkg/front_end/testcases/runtime_checks/covariant_generic_parameter_tear_off.dart.weak.expect
@@ -23,14 +23,14 @@ class C<T extends core::Object* = dynamic> extends core::Object {
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
 static method g1(self::C<core::num*>* c) → (core::num*) →* void {
-  return c.{self::C::f1}{(core::num*) →* void};
+  return c.{self::C::f1}{(core::num*) →* void} as{TypeError,CovarianceCheck} (core::num*) →* void;
 }
 static method g2(self::C<core::int*>* c, core::Object* x) → void {
   (core::Object*) →* void f = self::g1(c) as (core::Object*) →* void;
   f(x){(core::Object*) →* void};
 }
 static method g3(self::C<core::num*>* c) → (core::List<core::num*>*) →* core::num* {
-  return c.{self::C::f2}{(core::List<core::num*>*) →* core::num*};
+  return c.{self::C::f2}{(core::List<core::num*>*) →* core::num*} as{TypeError,CovarianceCheck} (core::List<core::num*>*) →* core::num*;
 }
 static method test() → void {
   (core::num*) →* void x = self::g1(new self::C::•<core::int*>());
diff --git a/pkg/front_end/testcases/runtime_checks/covariant_generic_parameter_tear_off.dart.weak.transformed.expect b/pkg/front_end/testcases/runtime_checks/covariant_generic_parameter_tear_off.dart.weak.transformed.expect
@@ -23,14 +23,14 @@ class C<T extends core::Object* = dynamic> extends core::Object {
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
 static method g1(self::C<core::num*>* c) → (core::num*) →* void {
-  return c.{self::C::f1}{(core::num*) →* void};
+  return c.{self::C::f1}{(core::num*) →* void} as{TypeError,CovarianceCheck} (core::num*) →* void;
 }
 static method g2(self::C<core::int*>* c, core::Object* x) → void {
   (core::Object*) →* void f = self::g1(c) as (core::Object*) →* void;
   f(x){(core::Object*) →* void};
 }
 static method g3(self::C<core::num*>* c) → (core::List<core::num*>*) →* core::num* {
-  return c.{self::C::f2}{(core::List<core::num*>*) →* core::num*};
+  return c.{self::C::f2}{(core::List<core::num*>*) →* core::num*} as{TypeError,CovarianceCheck} (core::List<core::num*>*) →* core::num*;
 }
 static method test() → void {
   (core::num*) →* void x = self::g1(new self::C::•<core::int*>());
diff --git a/pkg/kernel/lib/type_algebra.dart b/pkg/kernel/lib/type_algebra.dart
@@ -109,7 +109,9 @@ bool containsFreeTypeVariables(DartType type) {
 /// mapping to be used for replacing other types to use the new type parameters.
 FreshTypeParameters getFreshTypeParameters(List<TypeParameter> typeParameters) {
   List<TypeParameter> freshParameters = new List<TypeParameter>.generate(
-      typeParameters.length, (i) => new TypeParameter(typeParameters[i].name),
+      typeParameters.length,
+      (i) => new TypeParameter(typeParameters[i].name)
+        ..flags = typeParameters[i].flags,
       growable: true);
   List<DartType> freshTypeArguments =
       new List<DartType>.generate(typeParameters.length, (int i) {
@@ -138,8 +140,10 @@ FreshTypeParameters getFreshTypeParameters(List<TypeParameter> typeParameters) {
 class FreshTypeParameters {
   /// The newly created type parameters.
   final List<TypeParameter> freshTypeParameters;
+
   /// List of [TypeParameterType]s for [TypeParameter].
   final List<DartType> freshTypeArguments;
+
   /// Substitution from the original type parameters to [freshTypeArguments].
   final Substitution substitution;
 
@@ -389,7 +393,7 @@ class _InnerTypeSubstitutor extends _TypeSubstitutor {
   }
 
   TypeParameter freshTypeParameter(TypeParameter node) {
-    TypeParameter fresh = new TypeParameter(node.name);
+    TypeParameter fresh = new TypeParameter(node.name)..flags = node.flags;
     TypeParameterType typeParameterType = substitution[node] =
         new TypeParameterType.forAlphaRenaming(node, fresh);
     fresh.bound = visit(node.bound);

Original file line number	Diff line number	Diff line change
`@@ -15,7 +15,7 @@ class C<T> {`
`15`	`15`	`}`
`16`	`16`
`17`	`17`	`F<num> g1(C<num> c) {`
`18`		`- return c.f1;`
	`18`	`+ return c. /@ checkReturn=(num) ->* void*/ f1;`
`19`	`19`	`}`
`20`	`20`
`21`	`21`	`void g2(C<int> c, Object x) {`
`@@ -24,7 +24,7 @@ void g2(C<int> c, Object x) {`
`24`	`24`	`}`
`25`	`25`
`26`	`26`	`G<List<num>, num> g3(C<num> c) {`
`27`		`- return c.f2;`
	`27`	`+ return c. /@ checkReturn=(List<num>) -> num**/ f2;`
`28`	`28`	`}`
`29`	`29`
`30`	`30`	`void test() {`