[cfe] Support type inference on inline class constructor invocation

Closes #51146

Change-Id: I8fab2e999b29fbc811786e168d0e7a4c5a081418
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/295363
Reviewed-by: Chloe Stefantsova <cstefantsova@google.com>
Commit-Queue: Johnni Winther <johnniwinther@google.com>

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

@@ -1567,7 +1567,8 @@ class BodyBuilder extends StackListenerImpl
               named: arguments.named,
               hasExplicitTypeArguments: hasExplicitTypeArguments(arguments)),
           constness: isConst ? Constness.explicitConst : Constness.explicitNew,
-          charOffset: fileOffset);
+          charOffset: fileOffset,
+          isConstructorInvocation: true);
     }
     return replacementNode;
   }
@@ -5970,7 +5971,8 @@ class BodyBuilder extends StackListenerImpl
       {Constness constness = Constness.implicit,
       TypeAliasBuilder? typeAliasBuilder,
       int charOffset = -1,
-      int charLength = noLength}) {
+      int charLength = noLength,
+      required bool isConstructorInvocation}) {
     // The argument checks for the initial target of redirecting factories
     // invocations are skipped in Dart 1.
     List<TypeParameter> typeParameters = target.function!.typeParameters;
@@ -6018,7 +6020,7 @@ class BodyBuilder extends StackListenerImpl
       return node;
     } else {
       Procedure procedure = target as Procedure;
-      if (procedure.isFactory) {
+      if (isConstructorInvocation) {
         if (constantContext == ConstantContext.required &&
             constness == Constness.implicit) {
           addProblem(fasta.messageMissingExplicitConst, charOffset, charLength);
@@ -6051,8 +6053,7 @@ class BodyBuilder extends StackListenerImpl
         }
         return node;
       } else {
-        assert(
-            constness == Constness.implicit || procedure.isInlineClassMember);
+        assert(constness == Constness.implicit);
         return new StaticInvocation(target, arguments, isConst: false)
           ..fileOffset = charOffset;
       }
@@ -6494,7 +6495,8 @@ class BodyBuilder extends StackListenerImpl
                 constness: constness,
                 typeAliasBuilder: aliasBuilder,
                 charOffset: nameToken.charOffset,
-                charLength: nameToken.length);
+                charLength: nameToken.length,
+                isConstructorInvocation: true);
             return invocation;
           } else {
             return buildUnresolvedError(errorName, nameLastToken.charOffset,
@@ -6647,7 +6649,8 @@ class BodyBuilder extends StackListenerImpl
             constness: constness,
             charOffset: nameToken.charOffset,
             charLength: nameToken.length,
-            typeAliasBuilder: typeAliasBuilder as TypeAliasBuilder?);
+            typeAliasBuilder: typeAliasBuilder as TypeAliasBuilder?,
+            isConstructorInvocation: true);
         return invocation;
       } else {
         errorName ??= debugName(type.name, name);
@@ -6668,7 +6671,8 @@ class BodyBuilder extends StackListenerImpl
             constness: constness,
             charOffset: nameToken.charOffset,
             charLength: nameToken.length,
-            typeAliasBuilder: typeAliasBuilder as TypeAliasBuilder?);
+            typeAliasBuilder: typeAliasBuilder as TypeAliasBuilder?,
+            isConstructorInvocation: true);
       } else {
         errorName ??= debugName(type.name, name);
       }
@@ -8899,7 +8903,8 @@ class BodyBuilder extends StackListenerImpl
               forest.createStringLiteral(assignmentOffset, name)
             ]),
             constness: Constness.explicitNew,
-            charOffset: assignmentOffset);
+            charOffset: assignmentOffset,
+            isConstructorInvocation: true);
         return <Initializer>[
           new ShadowInvalidFieldInitializer(
               builder.field,

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

@@ -1555,7 +1555,7 @@ class StaticAccessGenerator extends Generator {
           arguments);
     } else {
       return _helper.buildStaticInvocation(readTarget as Procedure, arguments,
-          charOffset: offset);
+          charOffset: offset, isConstructorInvocation: false);
     }
   }
 

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

@@ -85,7 +85,8 @@ abstract class ExpressionGeneratorHelper implements InferenceHelper {
 
   Expression buildStaticInvocation(Member target, Arguments arguments,
       {Constness constness = Constness.implicit,
-      int charOffset = TreeNode.noOffset});
+      int charOffset = TreeNode.noOffset,
+      required bool isConstructorInvocation});
 
   Expression buildExtensionMethodInvocation(
       int fileOffset, Procedure target, Arguments arguments,

pkg/front_end/lib/src/fasta/kernel/hierarchy/mixin_inferrer.dart

@@ -88,6 +88,12 @@ class TypeBuilderConstraintGatherer extends TypeConstraintGatherer
     return hierarchy.getTypeArgumentsAsInstanceOf(type, superclass);
   }
 
+  @override
+  List<DartType>? getInlineTypeArgumentsAsInstanceOf(
+      InlineType type, InlineClass superclass) {
+    return hierarchy.getInlineTypeArgumentsAsInstanceOf(type, superclass);
+  }
+
   @override
   InterfaceType futureType(DartType type, Nullability nullability) {
     return new InterfaceType(

pkg/front_end/lib/src/fasta/source/source_enum_builder.dart

@@ -771,7 +771,8 @@ class SourceEnumBuilder extends SourceClassBuilder {
         Expression initializer = bodyBuilder.buildStaticInvocation(
             constructorBuilder.invokeTarget, arguments,
             constness: Constness.explicitConst,
-            charOffset: fieldBuilder.charOffset);
+            charOffset: fieldBuilder.charOffset,
+            isConstructorInvocation: true);
         ExpressionInferenceResult inferenceResult = bodyBuilder.typeInferrer
             .inferFieldInitializer(
                 bodyBuilder, const UnknownType(), initializer);

pkg/front_end/lib/src/fasta/source/source_library_builder.dart

@@ -4466,10 +4466,10 @@ class SourceLibraryBuilder extends LibraryBuilderImpl {
       {bool inferred = false}) {
     if (node.arguments.types.isEmpty) return;
     Procedure factory = node.target;
-    assert(factory.isFactory);
-    Class klass = factory.enclosingClass!;
-    DartType constructedType = new InterfaceType(
-        klass, klass.enclosingLibrary.nonNullable, node.arguments.types);
+    assert(factory.isFactory || factory.isInlineClassMember);
+    DartType constructedType = Substitution.fromPairs(
+            node.target.function.typeParameters, node.arguments.types)
+        .substituteType(node.target.function.returnType);
     checkBoundsInType(
         constructedType, typeEnvironment, fileUri, node.fileOffset,
         inferred: inferred, allowSuperBounded: false);

pkg/front_end/lib/src/fasta/type_inference/type_constraint_gatherer.dart

@@ -67,6 +67,9 @@ abstract class TypeConstraintGatherer {
   List<DartType>? getTypeArgumentsAsInstanceOf(
       InterfaceType type, Class superclass);
 
+  List<DartType>? getInlineTypeArgumentsAsInstanceOf(
+      InlineType type, InlineClass superclass);
+
   InterfaceType futureType(DartType type, Nullability nullability);
 
   /// Returns the set of type constraints that was gathered.
@@ -635,6 +638,21 @@ abstract class TypeConstraintGatherer {
         p.classNode == q.classNode) {
       assert(p.typeArguments.length == q.typeArguments.length);
 
+      final int baseConstraintCount = _protoConstraints.length;
+      bool isMatch = true;
+      for (int i = 0; isMatch && i < p.typeArguments.length; ++i) {
+        isMatch = isMatch &&
+            _isNullabilityAwareSubtypeMatch(
+                p.typeArguments[i], q.typeArguments[i],
+                constrainSupertype: constrainSupertype);
+      }
+      if (isMatch) return true;
+      _protoConstraints.length = baseConstraintCount;
+    } else if (p is InlineType &&
+        q is InlineType &&
+        p.inlineClass == q.inlineClass) {
+      assert(p.typeArguments.length == q.typeArguments.length);
+
       final int baseConstraintCount = _protoConstraints.length;
       bool isMatch = true;
       for (int i = 0; isMatch && i < p.typeArguments.length; ++i) {
@@ -659,6 +677,22 @@ abstract class TypeConstraintGatherer {
       if (sArguments != null) {
         assert(sArguments.length == q.typeArguments.length);
 
+        final int baseConstraintCount = _protoConstraints.length;
+        bool isMatch = true;
+        for (int i = 0; isMatch && i < sArguments.length; ++i) {
+          isMatch = isMatch &&
+              _isNullabilityAwareSubtypeMatch(sArguments[i], q.typeArguments[i],
+                  constrainSupertype: constrainSupertype);
+        }
+        if (isMatch) return true;
+        _protoConstraints.length = baseConstraintCount;
+      }
+    } else if (p is InlineType && q is InlineType) {
+      final List<DartType>? sArguments =
+          getInlineTypeArgumentsAsInstanceOf(p, q.inlineClass);
+      if (sArguments != null) {
+        assert(sArguments.length == q.typeArguments.length);
+
         final int baseConstraintCount = _protoConstraints.length;
         bool isMatch = true;
         for (int i = 0; isMatch && i < sArguments.length; ++i) {
@@ -1134,6 +1168,13 @@ class TypeSchemaConstraintGatherer extends TypeConstraintGatherer {
     return environment.getTypeArgumentsAsInstanceOf(type, superclass);
   }
 
+  @override
+  List<DartType>? getInlineTypeArgumentsAsInstanceOf(
+      InlineType type, InlineClass superclass) {
+    return environment.hierarchy
+        .getInlineTypeArgumentsAsInstanceOf(type, superclass);
+  }
+
   @override
   InterfaceType futureType(DartType type, Nullability nullability) {
     return environment.futureType(type, nullability);

pkg/front_end/testcases/inline_class/constructor_access.dart.strong.expect

@@ -35,7 +35,7 @@ static method main() → dynamic {
   self::GenericClass<core::String> e = self::GenericClass|<core::String>("bar");
   self::GenericClass<core::int> f = self::GenericClass|<core::int>(42);
   self::GenericClass<core::int> g = self::GenericClass|<core::int>(87);
-  self::GenericClass<core::num> h = self::GenericClass|<core::int>(123);
+  self::GenericClass<core::num> h = self::GenericClass|<core::num>(123);
   self::expect(3, a as{ForNonNullableByDefault} core::int);
   self::expect(3, a);
   self::expect(4, b as{ForNonNullableByDefault} core::int);

pkg/front_end/testcases/inline_class/constructor_access.dart.strong.transformed.expect

@@ -35,7 +35,7 @@ static method main() → dynamic {
   self::GenericClass<core::String> e = self::GenericClass|<core::String>("bar");
   self::GenericClass<core::int> f = self::GenericClass|<core::int>(42);
   self::GenericClass<core::int> g = self::GenericClass|<core::int>(87);
-  self::GenericClass<core::num> h = self::GenericClass|<core::int>(123);
+  self::GenericClass<core::num> h = self::GenericClass|<core::num>(123);
   self::expect(3, a as{ForNonNullableByDefault} core::int);
   self::expect(3, a);
   self::expect(4, b as{ForNonNullableByDefault} core::int);

pkg/front_end/testcases/inline_class/constructor_access.dart.weak.expect

@@ -35,7 +35,7 @@ static method main() → dynamic {
   self::GenericClass<core::String> e = self::GenericClass|<core::String>("bar");
   self::GenericClass<core::int> f = self::GenericClass|<core::int>(42);
   self::GenericClass<core::int> g = self::GenericClass|<core::int>(87);
-  self::GenericClass<core::num> h = self::GenericClass|<core::int>(123);
+  self::GenericClass<core::num> h = self::GenericClass|<core::num>(123);
   self::expect(3, a as{ForNonNullableByDefault} core::int);
   self::expect(3, a);
   self::expect(4, b as{ForNonNullableByDefault} core::int);

pkg/front_end/testcases/inline_class/constructor_access.dart.weak.modular.expect

@@ -35,7 +35,7 @@ static method main() → dynamic {
   self::GenericClass<core::String> e = self::GenericClass|<core::String>("bar");
   self::GenericClass<core::int> f = self::GenericClass|<core::int>(42);
   self::GenericClass<core::int> g = self::GenericClass|<core::int>(87);
-  self::GenericClass<core::num> h = self::GenericClass|<core::int>(123);
+  self::GenericClass<core::num> h = self::GenericClass|<core::num>(123);
   self::expect(3, a as{ForNonNullableByDefault} core::int);
   self::expect(3, a);
   self::expect(4, b as{ForNonNullableByDefault} core::int);

pkg/front_end/testcases/inline_class/constructor_access.dart.weak.transformed.expect

@@ -35,7 +35,7 @@ static method main() → dynamic {
   self::GenericClass<core::String> e = self::GenericClass|<core::String>("bar");
   self::GenericClass<core::int> f = self::GenericClass|<core::int>(42);
   self::GenericClass<core::int> g = self::GenericClass|<core::int>(87);
-  self::GenericClass<core::num> h = self::GenericClass|<core::int>(123);
+  self::GenericClass<core::num> h = self::GenericClass|<core::num>(123);
   self::expect(3, a as{ForNonNullableByDefault} core::int);
   self::expect(3, a);
   self::expect(4, b as{ForNonNullableByDefault} core::int);

pkg/front_end/testcases/inline_class/issue51146.dart

@@ -0,0 +1,14 @@
+// Copyright (c) 2023, 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.
+
+inline class I<X, Y> {
+  final X value;
+  I(this.value);
+}
+
+void f(I<int, String> i) {}
+
+void main() {
+  f(I(2));
+}

pkg/front_end/testcases/inline_class/issue51146.dart.strong.expect

@@ -0,0 +1,15 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "dart:core" as core;
+
+inline class I<X extends core::Object? = dynamic, Y extends core::Object? = dynamic> /* declaredRepresentationType = X% */ {
+  constructor • = self::I|;
+}
+static method I|<X extends core::Object? = dynamic, Y extends core::Object? = dynamic>(self::I|::X% value) → self::I<self::I|::X%, self::I|::Y%> {
+  final self::I<self::I|::X%, self::I|::Y%> #this = value;
+  return #this;
+}
+static method f(self::I<core::int, core::String> i) → void {}
+static method main() → void {
+  self::f(self::I|<core::int, core::String>(2));
+}

pkg/front_end/testcases/inline_class/issue51146.dart.strong.transformed.expect

@@ -0,0 +1,15 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "dart:core" as core;
+
+inline class I<X extends core::Object? = dynamic, Y extends core::Object? = dynamic> /* declaredRepresentationType = X% */ {
+  constructor • = self::I|;
+}
+static method I|<X extends core::Object? = dynamic, Y extends core::Object? = dynamic>(self::I|::X% value) → self::I<self::I|::X%, self::I|::Y%> {
+  final self::I<self::I|::X%, self::I|::Y%> #this = value;
+  return #this;
+}
+static method f(self::I<core::int, core::String> i) → void {}
+static method main() → void {
+  self::f(self::I|<core::int, core::String>(2));
+}

pkg/front_end/testcases/inline_class/issue51146.dart.textual_outline.expect

@@ -0,0 +1,7 @@
+inline class I<X, Y> {
+  final X value;
+  I(this.value);
+}
+
+void f(I<int, String> i) {}
+void main() {}

pkg/front_end/testcases/inline_class/issue51146.dart.textual_outline_modelled.expect

@@ -0,0 +1,7 @@
+inline class I<X, Y> {
+  I(this.value);
+  final X value;
+}
+
+void f(I<int, String> i) {}
+void main() {}

pkg/front_end/testcases/inline_class/issue51146.dart.weak.expect

@@ -0,0 +1,15 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "dart:core" as core;
+
+inline class I<X extends core::Object? = dynamic, Y extends core::Object? = dynamic> /* declaredRepresentationType = X% */ {
+  constructor • = self::I|;
+}
+static method I|<X extends core::Object? = dynamic, Y extends core::Object? = dynamic>(self::I|::X% value) → self::I<self::I|::X%, self::I|::Y%> {
+  final self::I<self::I|::X%, self::I|::Y%> #this = value;
+  return #this;
+}
+static method f(self::I<core::int, core::String> i) → void {}
+static method main() → void {
+  self::f(self::I|<core::int, core::String>(2));
+}

pkg/front_end/testcases/inline_class/issue51146.dart.weak.modular.expect

@@ -0,0 +1,15 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "dart:core" as core;
+
+inline class I<X extends core::Object? = dynamic, Y extends core::Object? = dynamic> /* declaredRepresentationType = X% */ {
+  constructor • = self::I|;
+}
+static method I|<X extends core::Object? = dynamic, Y extends core::Object? = dynamic>(self::I|::X% value) → self::I<self::I|::X%, self::I|::Y%> {
+  final self::I<self::I|::X%, self::I|::Y%> #this = value;
+  return #this;
+}
+static method f(self::I<core::int, core::String> i) → void {}
+static method main() → void {
+  self::f(self::I|<core::int, core::String>(2));
+}

pkg/front_end/testcases/inline_class/issue51146.dart.weak.outline.expect

@@ -0,0 +1,13 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "dart:core" as core;
+
+inline class I<X extends core::Object? = dynamic, Y extends core::Object? = dynamic> /* declaredRepresentationType = X% */ {
+  constructor • = self::I|;
+}
+static method I|<X extends core::Object? = dynamic, Y extends core::Object? = dynamic>(self::I|::X% value) → self::I<self::I|::X%, self::I|::Y%>
+  ;
+static method f(self::I<core::int, core::String> i) → void
+  ;
+static method main() → void
+  ;

pkg/front_end/testcases/inline_class/issue51146.dart.weak.transformed.expect

@@ -0,0 +1,15 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "dart:core" as core;
+
+inline class I<X extends core::Object? = dynamic, Y extends core::Object? = dynamic> /* declaredRepresentationType = X% */ {
+  constructor • = self::I|;
+}
+static method I|<X extends core::Object? = dynamic, Y extends core::Object? = dynamic>(self::I|::X% value) → self::I<self::I|::X%, self::I|::Y%> {
+  final self::I<self::I|::X%, self::I|::Y%> #this = value;
+  return #this;
+}
+static method f(self::I<core::int, core::String> i) → void {}
+static method main() → void {
+  self::f(self::I|<core::int, core::String>(2));
+}