[cfe] Handle dot shorthand invocations.

This CL adds the resolution of dot shorthand invocations.

At the point of parsing, we can't be sure whether the invocation is a method invocation or a constructor invocation. We'll resolve the name with the given context type to find out.

Bug: #59758
Change-Id: I136ab6c7522fe24d98a4613d102089d50c4cd8cd
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/412800
Reviewed-by: Chloe Stefantsova <[email protected]>
Commit-Queue: Kallen Tu <[email protected]>

Author: kallentu

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

@@ -10016,10 +10016,15 @@ class BodyBuilder extends StackListenerImpl
     assert(checkState(token, [ValueKinds.Selector]));
     Selector selector = pop() as Selector;
     if (libraryFeatures.dotShorthands.isEnabled) {
-      // TODO(kallentu): Handle invocations.
-
-      push(forest.createDotShorthandPropertyGet(
-          offsetForToken(token), selector.name));
+      if (selector is InvocationSelector) {
+        // e.g. `.parse(2)`
+        push(forest.createDotShorthandInvocation(
+            offsetForToken(token), selector.name, selector.arguments));
+      } else if (selector is PropertySelector) {
+        // e.g. `.zero`
+        push(forest.createDotShorthandPropertyGet(
+            offsetForToken(token), selector.name));
+      }
     }
   }
 }

pkg/front_end/lib/src/kernel/forest.dart

@@ -933,6 +933,11 @@ class Forest {
     return new DotShorthand(innerExpression)..fileOffset = fileOffset;
   }
 
+  DotShorthandInvocation createDotShorthandInvocation(
+      int fileOffset, Name name, Arguments arguments) {
+    return new DotShorthandInvocation(name, arguments)..fileOffset = fileOffset;
+  }
+
   DotShorthandPropertyGet createDotShorthandPropertyGet(
       int fileOffset, Name name) {
     return new DotShorthandPropertyGet(name)..fileOffset = fileOffset;

pkg/front_end/lib/src/kernel/internal_ast.dart

@@ -3248,6 +3248,38 @@ class DotShorthand extends InternalExpression {
   }
 }
 
+/// Internal expression for a dot shorthand head with arguments.
+/// (e.g. `.parse(42)`).
+///
+/// This node could represent a shorthand of a static method or a named
+/// constructor.
+class DotShorthandInvocation extends InternalExpression {
+  Name name;
+
+  Arguments arguments;
+
+  DotShorthandInvocation(this.name, this.arguments);
+
+  @override
+  ExpressionInferenceResult acceptInference(
+      InferenceVisitorImpl visitor, DartType typeContext) {
+    return visitor.visitDotShorthandInvocation(this, typeContext);
+  }
+
+  @override
+  String toString() {
+    return "DotShorthandInvocation(${toStringInternal()})";
+  }
+
+  @override
+  // Coverage-ignore(suite): Not run.
+  void toTextInternal(AstPrinter printer) {
+    printer.write('.');
+    printer.writeName(name);
+    printer.writeArguments(arguments);
+  }
+}
+
 /// Internal expression for a dot shorthand head with no arguments.
 /// (e.g. `.zero`).
 ///

pkg/front_end/lib/src/type_inference/inference_visitor.dart

@@ -30,7 +30,7 @@ import '../base/instrumentation.dart'
         InstrumentationValueForType,
         InstrumentationValueForTypeArgs;
 import '../base/problems.dart' as problems
-    show internalProblem, unhandled, unsupported;
+    show internalProblem, unhandled, unsupported, unimplemented;
 import '../base/uri_offset.dart';
 import '../codes/cfe_codes.dart';
 import '../kernel/body_builder.dart' show combineStatements;
@@ -12111,6 +12111,63 @@ class InferenceVisitorImpl extends InferenceVisitorBase
     return new ExpressionInferenceResult(rewrittenType, rewrittenExpr);
   }
 
+  ExpressionInferenceResult visitDotShorthandInvocation(
+      DotShorthandInvocation node, DartType typeContext) {
+    // Use the previously cached context type to determine the declaration
+    // member that we're trying to find.
+    DartType cachedContext = getDotShorthandContext().unwrapTypeSchemaView();
+    Member? member = findInterfaceMember(
+            cachedContext, node.name, node.fileOffset,
+            includeExtensionMethods: false,
+            isSetter: false,
+            isDotShorthand: true)
+        .member;
+
+    Expression expr;
+    if (member is Procedure) {
+      expr = new StaticInvocation(member, node.arguments)
+        ..fileOffset = node.fileOffset;
+    } else if (member == null && cachedContext is TypeDeclarationType) {
+      // Couldn't find a static method in the declaration so we'll try and find
+      // a constructor of that name instead.
+      Member? constructor =
+          findConstructor(cachedContext, node.name, node.fileOffset);
+      if (constructor is Constructor) {
+        // TODO(kallentu): Const constructors.
+        expr = new ConstructorInvocation(constructor, node.arguments,
+            isConst: false)
+          ..fileOffset = node.fileOffset;
+      } else if (constructor is Procedure) {
+        // [constructor] can be a [Procedure] if we have an extension type
+        // constructor.
+        expr = new StaticInvocation(constructor, node.arguments)
+          ..fileOffset = node.fileOffset;
+      } else {
+        // Coverage-ignore-block(suite): Not run.
+        // TODO(kallentu): This is temporary. Build a problem with an error
+        // specific to not being able to find a member named [node.name].
+        problems.unimplemented(
+            'Cannot find dot shorthand member of name ${node.name}',
+            node.fileOffset,
+            helper.uri);
+      }
+    } else {
+      // Coverage-ignore-block(suite): Not run.
+      // TODO(kallentu): This is temporary. Build a problem with an error on the
+      // bad context type.
+      problems.unimplemented(
+          'Cannot find dot shorthand member of name ${node.name} with '
+          'context $cachedContext',
+          node.fileOffset,
+          helper.uri);
+    }
+
+    ExpressionInferenceResult expressionInferenceResult =
+        inferExpression(expr, cachedContext);
+    flowAnalysis.forwardExpression(expressionInferenceResult.expression, node);
+    return expressionInferenceResult;
+  }
+
   ExpressionInferenceResult visitDotShorthandPropertyGet(
       DotShorthandPropertyGet node, DartType typeContext) {
     // Use the previously cached context type to determine the declaration
@@ -12123,9 +12180,13 @@ class InferenceVisitorImpl extends InferenceVisitorBase
 
     ExpressionInferenceResult expressionInferenceResult;
     if (member == null) {
+      // Coverage-ignore-block(suite): Not run.
       // TODO(kallentu): This is temporary. Build a problem with an error
       // specific to not being able to find a member named [node.name].
-      throw 'Error: Cannot find dot shorthand member.';
+      problems.unimplemented(
+          'Cannot find dot shorthand member of name ${node.name}',
+          node.fileOffset,
+          helper.uri);
     } else if (member is Procedure && !member.isGetter) {
       // Tearoff like `Object.new`;
       expressionInferenceResult =

pkg/front_end/lib/src/type_inference/inference_visitor_base.dart

@@ -1169,6 +1169,28 @@ abstract class InferenceVisitorBase implements InferenceVisitor {
     return defaultTarget;
   }
 
+  /// Finds a constructor of [type] called [name].
+  Member? findConstructor(TypeDeclarationType type, Name name, int fileOffset) {
+    assert(isKnown(type));
+
+    // TODO(Dart Model team): Seems like an abstraction level issue to require
+    // going from `Class` objects back to builders to find a `Member`.
+    DeclarationBuilder builder;
+    switch (type) {
+      case InterfaceType():
+        builder = engine.hierarchyBuilder.loader
+            .computeClassBuilderFromTargetClass(type.classNode);
+      case ExtensionType():
+        builder = engine.hierarchyBuilder.loader
+            .computeExtensionTypeBuilderFromTargetExtensionType(
+                type.extensionTypeDeclaration);
+    }
+
+    MemberBuilder? constructorBuilder = builder.findConstructorOrFactory(
+        name.text, fileOffset, helper.uri, libraryBuilder);
+    return constructorBuilder?.invokeTarget;
+  }
+
   /// Finds a member of [receiverType] called [name], and if it is found,
   /// reports it through instrumentation using [fileOffset].
   ///

pkg/front_end/test/coverage_suite_expected.dart

@@ -590,7 +590,7 @@ const Map<String, ({int hitCount, int missCount})> _expect = {
   ),
   // 100.0%.
   "package:front_end/src/kernel/body_builder.dart": (
-    hitCount: 7205,
+    hitCount: 7213,
     missCount: 0,
   ),
   // 100.0%.
@@ -660,7 +660,7 @@ const Map<String, ({int hitCount, int missCount})> _expect = {
   ),
   // 100.0%.
   "package:front_end/src/kernel/forest.dart": (
-    hitCount: 402,
+    hitCount: 405,
     missCount: 0,
   ),
   // 100.0%.
@@ -720,7 +720,7 @@ const Map<String, ({int hitCount, int missCount})> _expect = {
   ),
   // 100.0%.
   "package:front_end/src/kernel/internal_ast.dart": (
-    hitCount: 551,
+    hitCount: 554,
     missCount: 0,
   ),
   // 100.0%.
@@ -976,12 +976,12 @@ const Map<String, ({int hitCount, int missCount})> _expect = {
   ),
   // 100.0%.
   "package:front_end/src/type_inference/inference_visitor.dart": (
-    hitCount: 8178,
+    hitCount: 8208,
     missCount: 0,
   ),
   // 100.0%.
   "package:front_end/src/type_inference/inference_visitor_base.dart": (
-    hitCount: 2451,
+    hitCount: 2477,
     missCount: 0,
   ),
   // 100.0%.

pkg/front_end/testcases/dot_shorthands/constructor.dart

@@ -0,0 +1,13 @@
+// Copyright (c) 2025, 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 Color {
+  final int x;
+  Color.red() : x = 1;
+  Color(this.x);
+}
+
+void main() {
+  Color c = .red();
+}

pkg/front_end/testcases/dot_shorthands/constructor.dart.strong.expect

@@ -0,0 +1,16 @@
+library;
+import self as self;
+import "dart:core" as core;
+
+class Color extends core::Object {
+  final field core::int x;
+  constructor red() → self::Color
+    : self::Color::x = 1, super core::Object::•()
+    ;
+  constructor •(core::int x) → self::Color
+    : self::Color::x = x, super core::Object::•()
+    ;
+}
+static method main() → void {
+  self::Color c = new self::Color::red();
+}

pkg/front_end/testcases/dot_shorthands/constructor.dart.strong.modular.expect

@@ -0,0 +1,16 @@
+library;
+import self as self;
+import "dart:core" as core;
+
+class Color extends core::Object {
+  final field core::int x;
+  constructor red() → self::Color
+    : self::Color::x = 1, super core::Object::•()
+    ;
+  constructor •(core::int x) → self::Color
+    : self::Color::x = x, super core::Object::•()
+    ;
+}
+static method main() → void {
+  self::Color c = new self::Color::red();
+}

pkg/front_end/testcases/dot_shorthands/constructor.dart.strong.outline.expect

@@ -0,0 +1,13 @@
+library;
+import self as self;
+import "dart:core" as core;
+
+class Color extends core::Object {
+  final field core::int x;
+  constructor red() → self::Color
+    ;
+  constructor •(core::int x) → self::Color
+    ;
+}
+static method main() → void
+  ;

pkg/front_end/testcases/dot_shorthands/constructor.dart.strong.transformed.expect

@@ -0,0 +1,16 @@
+library;
+import self as self;
+import "dart:core" as core;
+
+class Color extends core::Object {
+  final field core::int x;
+  constructor red() → self::Color
+    : self::Color::x = 1, super core::Object::•()
+    ;
+  constructor •(core::int x) → self::Color
+    : self::Color::x = x, super core::Object::•()
+    ;
+}
+static method main() → void {
+  self::Color c = new self::Color::red();
+}

pkg/front_end/testcases/dot_shorthands/constructor.dart.textual_outline.expect

@@ -0,0 +1,7 @@
+class Color {
+  final int x;
+  Color.red() : x = 1;
+  Color(this.x);
+}
+
+void main() {}

pkg/front_end/testcases/dot_shorthands/constructor.dart.textual_outline_modelled.expect

@@ -0,0 +1,7 @@
+class Color {
+  Color(this.x);
+  Color.red() : x = 1;
+  final int x;
+}
+
+void main() {}

pkg/front_end/testcases/dot_shorthands/extension_type_constructor.dart

@@ -0,0 +1,11 @@
+// Copyright (c) 2025, 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.
+
+extension type IntegerExt(int integer) {
+  IntegerExt.regular(this.integer);
+}
+
+void main() {
+  IntegerExt c = .regular(1);
+}

pkg/front_end/testcases/dot_shorthands/extension_type_constructor.dart.strong.expect

@@ -0,0 +1,26 @@
+library;
+import self as self;
+import "dart:core" as core;
+
+extension type IntegerExt(core::int integer) {
+  abstract extension-type-member representation-field get integer() → core::int;
+  constructor • = self::IntegerExt|constructor#;
+  constructor tearoff • = self::IntegerExt|constructor#_#new#tearOff;
+  constructor regular = self::IntegerExt|constructor#regular;
+  constructor tearoff regular = self::IntegerExt|constructor#_#regular#tearOff;
+}
+static extension-type-member method IntegerExt|constructor#(core::int integer) → self::IntegerExt% /* erasure=core::int, declared=! */ {
+  lowered final self::IntegerExt% /* erasure=core::int, declared=! */ #this = integer;
+  return #this;
+}
+static extension-type-member method IntegerExt|constructor#_#new#tearOff(core::int integer) → self::IntegerExt% /* erasure=core::int, declared=! */
+  return self::IntegerExt|constructor#(integer);
+static extension-type-member method IntegerExt|constructor#regular(core::int integer) → self::IntegerExt% /* erasure=core::int, declared=! */ {
+  lowered final self::IntegerExt% /* erasure=core::int, declared=! */ #this = integer;
+  return #this;
+}
+static extension-type-member method IntegerExt|constructor#_#regular#tearOff(core::int integer) → self::IntegerExt% /* erasure=core::int, declared=! */
+  return self::IntegerExt|constructor#regular(integer);
+static method main() → void {
+  self::IntegerExt% /* erasure=core::int, declared=! */ c = self::IntegerExt|constructor#regular(1);
+}

pkg/front_end/testcases/dot_shorthands/extension_type_constructor.dart.strong.modular.expect

@@ -0,0 +1,26 @@
+library;
+import self as self;
+import "dart:core" as core;
+
+extension type IntegerExt(core::int integer) {
+  abstract extension-type-member representation-field get integer() → core::int;
+  constructor • = self::IntegerExt|constructor#;
+  constructor tearoff • = self::IntegerExt|constructor#_#new#tearOff;
+  constructor regular = self::IntegerExt|constructor#regular;
+  constructor tearoff regular = self::IntegerExt|constructor#_#regular#tearOff;
+}
+static extension-type-member method IntegerExt|constructor#(core::int integer) → self::IntegerExt% /* erasure=core::int, declared=! */ {
+  lowered final self::IntegerExt% /* erasure=core::int, declared=! */ #this = integer;
+  return #this;
+}
+static extension-type-member method IntegerExt|constructor#_#new#tearOff(core::int integer) → self::IntegerExt% /* erasure=core::int, declared=! */
+  return self::IntegerExt|constructor#(integer);
+static extension-type-member method IntegerExt|constructor#regular(core::int integer) → self::IntegerExt% /* erasure=core::int, declared=! */ {
+  lowered final self::IntegerExt% /* erasure=core::int, declared=! */ #this = integer;
+  return #this;
+}
+static extension-type-member method IntegerExt|constructor#_#regular#tearOff(core::int integer) → self::IntegerExt% /* erasure=core::int, declared=! */
+  return self::IntegerExt|constructor#regular(integer);
+static method main() → void {
+  self::IntegerExt% /* erasure=core::int, declared=! */ c = self::IntegerExt|constructor#regular(1);
+}