[cfe] If type variable is its own bound, set it to InvalidType

The motivation for this change is that we can't compute the nullability for such type parameter types anyways. Additionally, it stops the cascading error in case the type variable is its own bound indirectly, via a chain of other type variables. Change-Id: I940f19bb47952108ac1e0d1a0ef197b373b6b8e3 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/114946 Reviewed-by: Johnni Winther <johnniwinther@google.com> Commit-Queue: Dmitry Stefantsov <dmitryas@google.com>
2024-09-16 00:39:49 +00:00 · 2019-08-30 10:11:40 +00:00 · 2019-08-30 10:11:40 +00:00 · b8cde9347a
parent d4342b9021
commit b8cde9347a
5 changed files with 11 additions and 53 deletions
--- a/pkg/front_end/lib/src/fasta/source/outline_builder.dart
+++ b/pkg/front_end/lib/src/fasta/source/outline_builder.dart
@ -1610,6 +1610,11 @@ class OutlineBuilder extends StackListener {
                : templateCycleInTypeVariables.withArguments(
                    builder.name, via.join("', '"));
            addProblem(message, builder.charOffset, builder.name.length);
+            builder.bound = new NamedTypeBuilder(builder.name, null)
+              ..bind(new InvalidTypeBuilder(
+                  builder.name,
+                  message.withLocation(
+                      uri, builder.charOffset, builder.name.length)));
          }
        }
      }
--- a/pkg/front_end/messages.status
+++ b/pkg/front_end/messages.status
@ -124,8 +124,6 @@ CovariantMember/part_wrapped_script1: Fail
 CovariantMember/part_wrapped_script2: Fail
 CovariantMember/script1: Fail
 CovariantMember/script2: Fail
-CycleInTypeVariables/part_wrapped_script1: Fail
-CycleInTypeVariables/script1: Fail # We report an error for each type variable involved in the cycle.
 CyclicClassHierarchy/part_wrapped_script1: Fail
 CyclicClassHierarchy/part_wrapped_script2: Fail
 CyclicClassHierarchy/script1: Fail # We report an error for each class involved in the cycle.
--- a/pkg/front_end/testcases/instantiate_to_bound/multiple_strongly_connected.dart.outline.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/multiple_strongly_connected.dart.outline.expect
@ -7,21 +7,6 @@ library;
 // class I<T extends U, U extends Y, V extends Function(W), W extends Function(X),
 //         ^
 //
-// pkg/front_end/testcases/instantiate_to_bound/multiple_strongly_connected.dart:41:22: Error: Type 'U' is a bound of itself via 'Y', 'Z', 'T'.
-// Try breaking the cycle by removing at least on of the 'extends' clauses in the cycle.
-// class I<T extends U, U extends Y, V extends Function(W), W extends Function(X),
-//                      ^
-//
-// pkg/front_end/testcases/instantiate_to_bound/multiple_strongly_connected.dart:42:28: Error: Type 'Y' is a bound of itself via 'Z', 'T', 'U'.
-// Try breaking the cycle by removing at least on of the 'extends' clauses in the cycle.
-//     X extends Function(V), Y extends Z, Z extends T> {}
-//                            ^
-//
-// pkg/front_end/testcases/instantiate_to_bound/multiple_strongly_connected.dart:42:41: Error: Type 'Z' is a bound of itself via 'T', 'U', 'Y'.
-// Try breaking the cycle by removing at least on of the 'extends' clauses in the cycle.
-//     X extends Function(V), Y extends Z, Z extends T> {}
-//                                         ^
-//
 import self as self;
 import "dart:core" as core;

@ -57,7 +42,7 @@ class H<S extends self::A<self::H::S*>* = self::A<dynamic>*, T extends self::B<s
  synthetic constructor •() → self::H<self::H::S*, self::H::T*, self::H::U*, self::H::V*, self::H::W*, self::H::X*, self::H::Y*, self::H::Z*>*
    ;
 }
-class I<T extends self::I::U* = dynamic, U extends self::I::Y* = dynamic, V extends (self::I::W*) →* dynamic = (core::Null*) →* dynamic, W extends (self::I::X*) →* dynamic = (core::Null*) →* dynamic, X extends (self::I::V*) →* dynamic = (core::Null*) →* dynamic, Y extends self::I::Z* = dynamic, Z extends self::I::T* = dynamic> extends core::Object {
+class I<T extends invalid-type = invalid-type, U extends self::I::Y* = invalid-type, V extends (self::I::W*) →* dynamic = (core::Null*) →* dynamic, W extends (self::I::X*) →* dynamic = (core::Null*) →* dynamic, X extends (self::I::V*) →* dynamic = (core::Null*) →* dynamic, Y extends self::I::Z* = invalid-type, Z extends self::I::T* = invalid-type> extends core::Object {
  synthetic constructor •() → self::I<self::I::T*, self::I::U*, self::I::V*, self::I::W*, self::I::X*, self::I::Y*, self::I::Z*>*
    ;
 }
@ -70,7 +55,7 @@ static field self::E<self::B<dynamic, dynamic>*, self::C<dynamic, dynamic>*, sel
 static field self::F<core::num*, self::B<dynamic, dynamic>*, self::C<dynamic, dynamic>*, self::B<self::B<dynamic, dynamic>*, self::C<dynamic, dynamic>*>*, self::C<self::B<self::B<dynamic, dynamic>*, self::C<dynamic, dynamic>*>*, dynamic>*>* f;
 static field self::G<core::num*, self::B<core::num*, dynamic>*, self::C<dynamic, core::num*>*, self::B<self::B<core::num*, dynamic>*, self::C<dynamic, core::num*>*>*, self::C<self::B<self::B<core::num*, dynamic>*, self::C<dynamic, core::num*>*>*, dynamic>*>* g;
 static field self::H<self::A<dynamic>*, self::B<dynamic, dynamic>*, self::C<dynamic, dynamic>*, self::A<dynamic>*, self::A<dynamic>*, self::B<dynamic, dynamic>*, self::C<dynamic, dynamic>*, self::A<dynamic>*>* h;
-static field self::I<dynamic, dynamic, (core::Null*) →* dynamic, (core::Null*) →* dynamic, (core::Null*) →* dynamic, dynamic, dynamic>* i;
+static field self::I<invalid-type, invalid-type, (core::Null*) →* dynamic, (core::Null*) →* dynamic, (core::Null*) →* dynamic, invalid-type, invalid-type>* i;
 static field self::J<(core::Null*) →* dynamic, (core::Null*) →* dynamic, (core::Null*) →* dynamic, dynamic, dynamic, (core::Null*) →* dynamic, dynamic, dynamic>* j;
 static method main() → dynamic
  ;
--- a/pkg/front_end/testcases/instantiate_to_bound/multiple_strongly_connected.dart.strong.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/multiple_strongly_connected.dart.strong.expect
@ -7,21 +7,6 @@ library;
 // class I<T extends U, U extends Y, V extends Function(W), W extends Function(X),
 //         ^
 //
-// pkg/front_end/testcases/instantiate_to_bound/multiple_strongly_connected.dart:41:22: Error: Type 'U' is a bound of itself via 'Y', 'Z', 'T'.
-// Try breaking the cycle by removing at least on of the 'extends' clauses in the cycle.
-// class I<T extends U, U extends Y, V extends Function(W), W extends Function(X),
-//                      ^
-//
-// pkg/front_end/testcases/instantiate_to_bound/multiple_strongly_connected.dart:42:28: Error: Type 'Y' is a bound of itself via 'Z', 'T', 'U'.
-// Try breaking the cycle by removing at least on of the 'extends' clauses in the cycle.
-//     X extends Function(V), Y extends Z, Z extends T> {}
-//                            ^
-//
-// pkg/front_end/testcases/instantiate_to_bound/multiple_strongly_connected.dart:42:41: Error: Type 'Z' is a bound of itself via 'T', 'U', 'Y'.
-// Try breaking the cycle by removing at least on of the 'extends' clauses in the cycle.
-//     X extends Function(V), Y extends Z, Z extends T> {}
-//                                         ^
-//
 import self as self;
 import "dart:core" as core;

@ -65,7 +50,7 @@ class H<S extends self::A<self::H::S*>* = self::A<dynamic>*, T extends self::B<s
    : super core::Object::•()
    ;
 }
-class I<T extends self::I::U* = dynamic, U extends self::I::Y* = dynamic, V extends (self::I::W*) →* dynamic = (core::Null*) →* dynamic, W extends (self::I::X*) →* dynamic = (core::Null*) →* dynamic, X extends (self::I::V*) →* dynamic = (core::Null*) →* dynamic, Y extends self::I::Z* = dynamic, Z extends self::I::T* = dynamic> extends core::Object {
+class I<T extends invalid-type = invalid-type, U extends self::I::Y* = invalid-type, V extends (self::I::W*) →* dynamic = (core::Null*) →* dynamic, W extends (self::I::X*) →* dynamic = (core::Null*) →* dynamic, X extends (self::I::V*) →* dynamic = (core::Null*) →* dynamic, Y extends self::I::Z* = invalid-type, Z extends self::I::T* = invalid-type> extends core::Object {
  synthetic constructor •() → self::I<self::I::T*, self::I::U*, self::I::V*, self::I::W*, self::I::X*, self::I::Y*, self::I::Z*>*
    : super core::Object::•()
    ;
@ -80,6 +65,6 @@ static field self::E<self::B<dynamic, dynamic>*, self::C<dynamic, dynamic>*, sel
 static field self::F<core::num*, self::B<dynamic, dynamic>*, self::C<dynamic, dynamic>*, self::B<self::B<dynamic, dynamic>*, self::C<dynamic, dynamic>*>*, self::C<self::B<self::B<dynamic, dynamic>*, self::C<dynamic, dynamic>*>*, dynamic>*>* f;
 static field self::G<core::num*, self::B<core::num*, dynamic>*, self::C<dynamic, core::num*>*, self::B<self::B<core::num*, dynamic>*, self::C<dynamic, core::num*>*>*, self::C<self::B<self::B<core::num*, dynamic>*, self::C<dynamic, core::num*>*>*, dynamic>*>* g;
 static field self::H<self::A<dynamic>*, self::B<dynamic, dynamic>*, self::C<dynamic, dynamic>*, self::A<dynamic>*, self::A<dynamic>*, self::B<dynamic, dynamic>*, self::C<dynamic, dynamic>*, self::A<dynamic>*>* h;
-static field self::I<dynamic, dynamic, (core::Null*) →* dynamic, (core::Null*) →* dynamic, (core::Null*) →* dynamic, dynamic, dynamic>* i;
+static field self::I<invalid-type, invalid-type, (core::Null*) →* dynamic, (core::Null*) →* dynamic, (core::Null*) →* dynamic, invalid-type, invalid-type>* i;
 static field self::J<(core::Null*) →* dynamic, (core::Null*) →* dynamic, (core::Null*) →* dynamic, dynamic, dynamic, (core::Null*) →* dynamic, dynamic, dynamic>* j;
 static method main() → dynamic {}
--- a/pkg/front_end/testcases/instantiate_to_bound/multiple_strongly_connected.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/multiple_strongly_connected.dart.strong.transformed.expect
@ -7,21 +7,6 @@ library;
 // class I<T extends U, U extends Y, V extends Function(W), W extends Function(X),
 //         ^
 //
-// pkg/front_end/testcases/instantiate_to_bound/multiple_strongly_connected.dart:41:22: Error: Type 'U' is a bound of itself via 'Y', 'Z', 'T'.
-// Try breaking the cycle by removing at least on of the 'extends' clauses in the cycle.
-// class I<T extends U, U extends Y, V extends Function(W), W extends Function(X),
-//                      ^
-//
-// pkg/front_end/testcases/instantiate_to_bound/multiple_strongly_connected.dart:42:28: Error: Type 'Y' is a bound of itself via 'Z', 'T', 'U'.
-// Try breaking the cycle by removing at least on of the 'extends' clauses in the cycle.
-//     X extends Function(V), Y extends Z, Z extends T> {}
-//                            ^
-//
-// pkg/front_end/testcases/instantiate_to_bound/multiple_strongly_connected.dart:42:41: Error: Type 'Z' is a bound of itself via 'T', 'U', 'Y'.
-// Try breaking the cycle by removing at least on of the 'extends' clauses in the cycle.
-//     X extends Function(V), Y extends Z, Z extends T> {}
-//                                         ^
-//
 import self as self;
 import "dart:core" as core;

@ -65,7 +50,7 @@ class H<S extends self::A<self::H::S*>* = self::A<dynamic>*, T extends self::B<s
    : super core::Object::•()
    ;
 }
-class I<T extends self::I::U* = dynamic, U extends self::I::Y* = dynamic, V extends (self::I::W*) →* dynamic = (core::Null*) →* dynamic, W extends (self::I::X*) →* dynamic = (core::Null*) →* dynamic, X extends (self::I::V*) →* dynamic = (core::Null*) →* dynamic, Y extends self::I::Z* = dynamic, Z extends self::I::T* = dynamic> extends core::Object {
+class I<T extends invalid-type = invalid-type, U extends self::I::Y* = invalid-type, V extends (self::I::W*) →* dynamic = (core::Null*) →* dynamic, W extends (self::I::X*) →* dynamic = (core::Null*) →* dynamic, X extends (self::I::V*) →* dynamic = (core::Null*) →* dynamic, Y extends self::I::Z* = invalid-type, Z extends self::I::T* = invalid-type> extends core::Object {
  synthetic constructor •() → self::I<self::I::T*, self::I::U*, self::I::V*, self::I::W*, self::I::X*, self::I::Y*, self::I::Z*>*
    : super core::Object::•()
    ;
@ -80,6 +65,6 @@ static field self::E<self::B<dynamic, dynamic>*, self::C<dynamic, dynamic>*, sel
 static field self::F<core::num*, self::B<dynamic, dynamic>*, self::C<dynamic, dynamic>*, self::B<self::B<dynamic, dynamic>*, self::C<dynamic, dynamic>*>*, self::C<self::B<self::B<dynamic, dynamic>*, self::C<dynamic, dynamic>*>*, dynamic>*>* f;
 static field self::G<core::num*, self::B<core::num*, dynamic>*, self::C<dynamic, core::num*>*, self::B<self::B<core::num*, dynamic>*, self::C<dynamic, core::num*>*>*, self::C<self::B<self::B<core::num*, dynamic>*, self::C<dynamic, core::num*>*>*, dynamic>*>* g;
 static field self::H<self::A<dynamic>*, self::B<dynamic, dynamic>*, self::C<dynamic, dynamic>*, self::A<dynamic>*, self::A<dynamic>*, self::B<dynamic, dynamic>*, self::C<dynamic, dynamic>*, self::A<dynamic>*>* h;
-static field self::I<dynamic, dynamic, (core::Null*) →* dynamic, (core::Null*) →* dynamic, (core::Null*) →* dynamic, dynamic, dynamic>* i;
+static field self::I<invalid-type, invalid-type, (core::Null*) →* dynamic, (core::Null*) →* dynamic, (core::Null*) →* dynamic, invalid-type, invalid-type>* i;
 static field self::J<(core::Null*) →* dynamic, (core::Null*) →* dynamic, (core::Null*) →* dynamic, dynamic, dynamic, (core::Null*) →* dynamic, dynamic, dynamic>* j;
 static method main() → dynamic {}