[cfe] Handle erroneous enum constant values in exhaustiveness

Closes #54267

Change-Id: Ic8e86a352725bd35985fbd4685b1c4d446875949
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/345063
Reviewed-by: Chloe Stefantsova <cstefantsova@google.com>
Commit-Queue: Johnni Winther <johnniwinther@google.com>

pkg/front_end/lib/src/fasta/kernel/exhaustiveness.dart

@@ -382,7 +382,7 @@ class CfeEnumOperations
   }
 
   @override
-  EnumValue getEnumElementValue(Field enumField) {
+  EnumValue? getEnumElementValue(Field enumField) {
     // Enum field initializers might not have been replaced by
     // [ConstantExpression]s. Either because we haven't visited them yet during
     // normal constant evaluation or because they are from outlines that are
@@ -392,7 +392,7 @@ class CfeEnumOperations
     StaticTypeContext context =
         new StaticTypeContext(enumField, _constantEvaluator.typeEnvironment);
     return constantToEnumValue(_constantEvaluator.coreTypes,
-        _constantEvaluator.evaluate(context, enumField.initializer!))!;
+        _constantEvaluator.evaluate(context, enumField.initializer!));
   }
 
   @override

pkg/front_end/testcases/general/issue54267a.dart

@@ -0,0 +1,15 @@
+// Copyright (c) 2024, 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.
+
+enum A {
+  a(0),
+  b(1),
+  final int value;
+  const A(this.value);
+}
+
+int fn(A a) => switch (a) {
+  A.a => 0,
+  A.b => 1,
+};

pkg/front_end/testcases/general/issue54267a.dart.strong.expect

@@ -0,0 +1,76 @@
+library;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/general/issue54267a.dart:8:3: Error: Expected an identifier, but got 'final'.
+// Try inserting an identifier before 'final'.
+//   final int value;
+//   ^^^^^
+//
+// pkg/front_end/testcases/general/issue54267a.dart:8:3: Error: Expected '}' before this.
+//   final int value;
+//   ^^^^^
+//
+// pkg/front_end/testcases/general/issue54267a.dart:6:4: Error: Too many positional arguments: 2 allowed, but 3 found.
+// Try removing the extra positional arguments.
+//   a(0),
+//    ^
+// pkg/front_end/testcases/general/issue54267a.dart:5:6: Context: The class 'A' has a constructor that takes no arguments.
+// enum A {
+//      ^
+//
+// pkg/front_end/testcases/general/issue54267a.dart:7:4: Error: Too many positional arguments: 2 allowed, but 3 found.
+// Try removing the extra positional arguments.
+//   b(1),
+//    ^
+// pkg/front_end/testcases/general/issue54267a.dart:5:6: Context: The class 'A' has a constructor that takes no arguments.
+// enum A {
+//      ^
+//
+import self as self;
+import "dart:core" as core;
+
+class A extends core::_Enum /*isEnum*/  {
+  static const field core::List<self::A> values = invalid-expression "pkg/front_end/testcases/general/issue54267a.dart:6:4: Error: Too many positional arguments: 2 allowed, but 3 found.
+Try removing the extra positional arguments.
+  a(0),
+   ^";
+  enum-element static const field invalid-type a = invalid-expression "pkg/front_end/testcases/general/issue54267a.dart:6:4: Error: Too many positional arguments: 2 allowed, but 3 found.
+Try removing the extra positional arguments.
+  a(0),
+   ^";
+  enum-element static const field invalid-type b = invalid-expression "pkg/front_end/testcases/general/issue54267a.dart:7:4: Error: Too many positional arguments: 2 allowed, but 3 found.
+Try removing the extra positional arguments.
+  b(1),
+   ^";
+  const synthetic constructor •(core::int #index, core::String #name) → self::A
+    : super core::_Enum::•(#index, #name)
+    ;
+  method _enumToString() → core::String
+    return "A.${this.{core::_Enum::_name}{core::String}}";
+}
+static method fn(self::A a) → core::int
+  return block {
+    core::int #t1;
+    #L1:
+    switch(a) /* isExplicitlyExhaustive, self::A */ {
+      #L2:
+      case invalid-expression "pkg/front_end/testcases/general/issue54267a.dart:6:4: Error: Too many positional arguments: 2 allowed, but 3 found.
+Try removing the extra positional arguments.
+  a(0),
+   ^":
+        {
+          #t1 = 0;
+          break #L1;
+        }
+      #L3:
+      case invalid-expression "pkg/front_end/testcases/general/issue54267a.dart:7:4: Error: Too many positional arguments: 2 allowed, but 3 found.
+Try removing the extra positional arguments.
+  b(1),
+   ^":
+        {
+          #t1 = 1;
+          break #L1;
+        }
+    }
+  } =>#t1;

pkg/front_end/testcases/general/issue54267a.dart.strong.transformed.expect

@@ -0,0 +1,76 @@
+library;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/general/issue54267a.dart:8:3: Error: Expected an identifier, but got 'final'.
+// Try inserting an identifier before 'final'.
+//   final int value;
+//   ^^^^^
+//
+// pkg/front_end/testcases/general/issue54267a.dart:8:3: Error: Expected '}' before this.
+//   final int value;
+//   ^^^^^
+//
+// pkg/front_end/testcases/general/issue54267a.dart:6:4: Error: Too many positional arguments: 2 allowed, but 3 found.
+// Try removing the extra positional arguments.
+//   a(0),
+//    ^
+// pkg/front_end/testcases/general/issue54267a.dart:5:6: Context: The class 'A' has a constructor that takes no arguments.
+// enum A {
+//      ^
+//
+// pkg/front_end/testcases/general/issue54267a.dart:7:4: Error: Too many positional arguments: 2 allowed, but 3 found.
+// Try removing the extra positional arguments.
+//   b(1),
+//    ^
+// pkg/front_end/testcases/general/issue54267a.dart:5:6: Context: The class 'A' has a constructor that takes no arguments.
+// enum A {
+//      ^
+//
+import self as self;
+import "dart:core" as core;
+
+class A extends core::_Enum /*isEnum*/  {
+  static const field core::List<self::A> values = invalid-expression "pkg/front_end/testcases/general/issue54267a.dart:6:4: Error: Too many positional arguments: 2 allowed, but 3 found.
+Try removing the extra positional arguments.
+  a(0),
+   ^";
+  enum-element static const field invalid-type a = invalid-expression "pkg/front_end/testcases/general/issue54267a.dart:6:4: Error: Too many positional arguments: 2 allowed, but 3 found.
+Try removing the extra positional arguments.
+  a(0),
+   ^";
+  enum-element static const field invalid-type b = invalid-expression "pkg/front_end/testcases/general/issue54267a.dart:7:4: Error: Too many positional arguments: 2 allowed, but 3 found.
+Try removing the extra positional arguments.
+  b(1),
+   ^";
+  const synthetic constructor •(core::int #index, core::String #name) → self::A
+    : super core::_Enum::•(#index, #name)
+    ;
+  method _enumToString() → core::String
+    return "A.${this.{core::_Enum::_name}{core::String}}";
+}
+static method fn(self::A a) → core::int
+  return block {
+    core::int #t1;
+    #L1:
+    switch(a) /* isExplicitlyExhaustive, self::A */ {
+      #L2:
+      case invalid-expression "pkg/front_end/testcases/general/issue54267a.dart:6:4: Error: Too many positional arguments: 2 allowed, but 3 found.
+Try removing the extra positional arguments.
+  a(0),
+   ^":
+        {
+          #t1 = 0;
+          break #L1;
+        }
+      #L3:
+      case invalid-expression "pkg/front_end/testcases/general/issue54267a.dart:7:4: Error: Too many positional arguments: 2 allowed, but 3 found.
+Try removing the extra positional arguments.
+  b(1),
+   ^":
+        {
+          #t1 = 1;
+          break #L1;
+        }
+    }
+  } =>#t1;

pkg/front_end/testcases/general/issue54267a.dart.textual_outline.expect

@@ -0,0 +1,2 @@
+enum A { a(0), b(1), final int value; const A(this.value); }
+int fn(A a) => switch (a) { A.a => 0, A.b => 1, };

pkg/front_end/testcases/general/issue54267a.dart.textual_outline_modelled.expect

@@ -0,0 +1,2 @@
+enum A { a(0), b(1), final int value; const A(this.value); }
+int fn(A a) => switch (a) { A.a => 0, A.b => 1, };

pkg/front_end/testcases/general/issue54267a.dart.weak.expect

@@ -0,0 +1,80 @@
+library;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/general/issue54267a.dart:8:3: Error: Expected an identifier, but got 'final'.
+// Try inserting an identifier before 'final'.
+//   final int value;
+//   ^^^^^
+//
+// pkg/front_end/testcases/general/issue54267a.dart:8:3: Error: Expected '}' before this.
+//   final int value;
+//   ^^^^^
+//
+// pkg/front_end/testcases/general/issue54267a.dart:6:4: Error: Too many positional arguments: 2 allowed, but 3 found.
+// Try removing the extra positional arguments.
+//   a(0),
+//    ^
+// pkg/front_end/testcases/general/issue54267a.dart:5:6: Context: The class 'A' has a constructor that takes no arguments.
+// enum A {
+//      ^
+//
+// pkg/front_end/testcases/general/issue54267a.dart:7:4: Error: Too many positional arguments: 2 allowed, but 3 found.
+// Try removing the extra positional arguments.
+//   b(1),
+//    ^
+// pkg/front_end/testcases/general/issue54267a.dart:5:6: Context: The class 'A' has a constructor that takes no arguments.
+// enum A {
+//      ^
+//
+import self as self;
+import "dart:core" as core;
+import "dart:_internal" as _in;
+
+class A extends core::_Enum /*isEnum*/  {
+  static const field core::List<self::A> values = invalid-expression "pkg/front_end/testcases/general/issue54267a.dart:6:4: Error: Too many positional arguments: 2 allowed, but 3 found.
+Try removing the extra positional arguments.
+  a(0),
+   ^";
+  enum-element static const field invalid-type a = invalid-expression "pkg/front_end/testcases/general/issue54267a.dart:6:4: Error: Too many positional arguments: 2 allowed, but 3 found.
+Try removing the extra positional arguments.
+  a(0),
+   ^";
+  enum-element static const field invalid-type b = invalid-expression "pkg/front_end/testcases/general/issue54267a.dart:7:4: Error: Too many positional arguments: 2 allowed, but 3 found.
+Try removing the extra positional arguments.
+  b(1),
+   ^";
+  const synthetic constructor •(core::int #index, core::String #name) → self::A
+    : super core::_Enum::•(#index, #name)
+    ;
+  method _enumToString() → core::String
+    return "A.${this.{core::_Enum::_name}{core::String}}";
+}
+static method fn(self::A a) → core::int
+  return block {
+    core::int #t1;
+    #L1:
+    switch(a) /* isExplicitlyExhaustive, self::A */ {
+      #L2:
+      case invalid-expression "pkg/front_end/testcases/general/issue54267a.dart:6:4: Error: Too many positional arguments: 2 allowed, but 3 found.
+Try removing the extra positional arguments.
+  a(0),
+   ^":
+        {
+          #t1 = 0;
+          break #L1;
+        }
+      #L3:
+      case invalid-expression "pkg/front_end/testcases/general/issue54267a.dart:7:4: Error: Too many positional arguments: 2 allowed, but 3 found.
+Try removing the extra positional arguments.
+  b(1),
+   ^":
+        {
+          #t1 = 1;
+          break #L1;
+        }
+      #L4:
+      default:
+        throw new _in::ReachabilityError::•("`null` encountered as case in a switch expression with a non-nullable type.");
+    }
+  } =>#t1;

pkg/front_end/testcases/general/issue54267a.dart.weak.modular.expect

@@ -0,0 +1,80 @@
+library;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/general/issue54267a.dart:8:3: Error: Expected an identifier, but got 'final'.
+// Try inserting an identifier before 'final'.
+//   final int value;
+//   ^^^^^
+//
+// pkg/front_end/testcases/general/issue54267a.dart:8:3: Error: Expected '}' before this.
+//   final int value;
+//   ^^^^^
+//
+// pkg/front_end/testcases/general/issue54267a.dart:6:4: Error: Too many positional arguments: 2 allowed, but 3 found.
+// Try removing the extra positional arguments.
+//   a(0),
+//    ^
+// pkg/front_end/testcases/general/issue54267a.dart:5:6: Context: The class 'A' has a constructor that takes no arguments.
+// enum A {
+//      ^
+//
+// pkg/front_end/testcases/general/issue54267a.dart:7:4: Error: Too many positional arguments: 2 allowed, but 3 found.
+// Try removing the extra positional arguments.
+//   b(1),
+//    ^
+// pkg/front_end/testcases/general/issue54267a.dart:5:6: Context: The class 'A' has a constructor that takes no arguments.
+// enum A {
+//      ^
+//
+import self as self;
+import "dart:core" as core;
+import "dart:_internal" as _in;
+
+class A extends core::_Enum /*isEnum*/  {
+  static const field core::List<self::A> values = invalid-expression "pkg/front_end/testcases/general/issue54267a.dart:6:4: Error: Too many positional arguments: 2 allowed, but 3 found.
+Try removing the extra positional arguments.
+  a(0),
+   ^";
+  enum-element static const field invalid-type a = invalid-expression "pkg/front_end/testcases/general/issue54267a.dart:6:4: Error: Too many positional arguments: 2 allowed, but 3 found.
+Try removing the extra positional arguments.
+  a(0),
+   ^";
+  enum-element static const field invalid-type b = invalid-expression "pkg/front_end/testcases/general/issue54267a.dart:7:4: Error: Too many positional arguments: 2 allowed, but 3 found.
+Try removing the extra positional arguments.
+  b(1),
+   ^";
+  const synthetic constructor •(core::int #index, core::String #name) → self::A
+    : super core::_Enum::•(#index, #name)
+    ;
+  method _enumToString() → core::String
+    return "A.${this.{core::_Enum::_name}{core::String}}";
+}
+static method fn(self::A a) → core::int
+  return block {
+    core::int #t1;
+    #L1:
+    switch(a) /* isExplicitlyExhaustive, self::A */ {
+      #L2:
+      case invalid-expression "pkg/front_end/testcases/general/issue54267a.dart:6:4: Error: Too many positional arguments: 2 allowed, but 3 found.
+Try removing the extra positional arguments.
+  a(0),
+   ^":
+        {
+          #t1 = 0;
+          break #L1;
+        }
+      #L3:
+      case invalid-expression "pkg/front_end/testcases/general/issue54267a.dart:7:4: Error: Too many positional arguments: 2 allowed, but 3 found.
+Try removing the extra positional arguments.
+  b(1),
+   ^":
+        {
+          #t1 = 1;
+          break #L1;
+        }
+      #L4:
+      default:
+        throw new _in::ReachabilityError::•("`null` encountered as case in a switch expression with a non-nullable type.");
+    }
+  } =>#t1;