[cfe] Handle duplicates in augmentation libraries

Change-Id: I6200ffa7e3b2b68dbda2233f8bd3da7c76d7438a
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/259360
Reviewed-by: Jens Johansen <[email protected]>
Commit-Queue: Johnni Winther <[email protected]>

Author: johnniwinther

pkg/front_end/lib/src/fasta/scope.dart

@@ -1369,13 +1369,24 @@ abstract class MergedScope<T extends Builder> {
   }
 
   void _addAugmentationScope(T parentBuilder, Scope scope) {
+    // TODO(johnniwinther): Use `scope.filteredNameIterator` instead of
+    // `scope.forEachLocalMember`/`scope.forEachLocalSetter`.
+
     // Include all augmentation scope members to the origin scope.
     scope.forEachLocalMember((String name, Builder member) {
+      // In case of duplicates we use the first declaration.
+      while (member.isDuplicate) {
+        member = member.next!;
+      }
       _addBuilderToMergedScope(parentBuilder, name, member,
           _originScope.lookupLocalMember(name, setter: false),
           setter: false);
     });
     scope.forEachLocalSetter((String name, Builder member) {
+      // In case of duplicates we use the first declaration.
+      while (member.isDuplicate) {
+        member = member.next!;
+      }
       _addBuilderToMergedScope(parentBuilder, name, member,
           _originScope.lookupLocalMember(name, setter: true),
           setter: true);

pkg/front_end/testcases/general/multiple_class_patches/libraries.json

@@ -0,0 +1,13 @@
+{
+  "none": {
+    "libraries": {
+      "test": {
+        "patches": [
+          "patch_lib1.dart",
+          "patch_lib2.dart"
+        ],
+        "uri": "origin_lib.dart"
+      }
+    }
+  }
+}

pkg/front_end/testcases/general/multiple_class_patches/main.dart

@@ -0,0 +1,18 @@
+// Copyright (c) 2022, 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.
+
+import 'dart:test';
+
+main() {
+  Class c = new Class();
+  expect(42, c.method1());
+  expect(87, c.method2());
+  expect(123, c.method3());
+}
+
+expect(expected, actual) {
+  if (expected != actual) {
+    throw 'Expected $expected, actual $actual';
+  }
+}

pkg/front_end/testcases/general/multiple_class_patches/main.dart.textual_outline.expect

@@ -0,0 +1,4 @@
+import 'dart:test';
+
+main() {}
+expect(expected, actual) {}

pkg/front_end/testcases/general/multiple_class_patches/main.dart.textual_outline_modelled.expect

@@ -0,0 +1,4 @@
+import 'dart:test';
+
+expect(expected, actual) {}
+main() {}

pkg/front_end/testcases/general/multiple_class_patches/main.dart.weak.expect

@@ -0,0 +1,66 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "dart:test" as test;
+import "dart:core" as core;
+
+import "dart:test";
+
+static method main() → dynamic {
+  test::Class c = new test::Class::•();
+  self::expect(42, c.{test::Class::method1}(){() → core::int});
+  self::expect(87, c.{test::Class::method2}(){() → core::int});
+  self::expect(123, c.{test::Class::method3}(){() → core::int});
+}
+static method expect(dynamic expected, dynamic actual) → dynamic {
+  if(!(expected =={core::Object::==}{(core::Object) → core::bool} actual)) {
+    throw "Expected ${expected}, actual ${actual}";
+  }
+}
+
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/general/multiple_class_patches/patch_lib2.dart:9:7: Error: 'Class' is already declared in this scope.
+// class Class {
+//       ^^^^^
+// pkg/front_end/testcases/general/multiple_class_patches/patch_lib1.dart:9:7: Context: Previous declaration of 'Class'.
+// class Class {
+//       ^^^^^
+//
+import self as test;
+import "dart:_internal" as _in;
+import "dart:core" as core;
+
+import "dart:_internal";
+import "dart:_internal";
+
+@#C1
+class Class#1#1 extends core::Object { // from org-dartlang-testcase:///patch_lib2.dart
+  synthetic constructor •() → test::Class#1#1
+    : super core::Object::•()
+    ;
+  @#C1
+  method method2() → core::int
+    return 87;
+  @#C1
+  method method3() → core::int
+    return 123;
+}
+@#C1
+class Class extends core::Object {
+  synthetic constructor •() → test::Class
+    : super core::Object::•()
+    ;
+  @#C1
+  method /* from org-dartlang-testcase:///patch_lib1.dart */ method1() → core::int
+    return 42;
+  external method method2() → core::int;
+  @#C1
+  method /* from org-dartlang-testcase:///patch_lib1.dart */ method3() → core::int
+    return 321;
+}
+
+constants  {
+  #C1 = _in::_Patch {}
+}

pkg/front_end/testcases/general/multiple_class_patches/main.dart.weak.modular.expect

@@ -0,0 +1,66 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "dart:test" as test;
+import "dart:core" as core;
+
+import "dart:test";
+
+static method main() → dynamic {
+  test::Class c = new test::Class::•();
+  self::expect(42, c.{test::Class::method1}(){() → core::int});
+  self::expect(87, c.{test::Class::method2}(){() → core::int});
+  self::expect(123, c.{test::Class::method3}(){() → core::int});
+}
+static method expect(dynamic expected, dynamic actual) → dynamic {
+  if(!(expected =={core::Object::==}{(core::Object) → core::bool} actual)) {
+    throw "Expected ${expected}, actual ${actual}";
+  }
+}
+
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/general/multiple_class_patches/patch_lib2.dart:9:7: Error: 'Class' is already declared in this scope.
+// class Class {
+//       ^^^^^
+// pkg/front_end/testcases/general/multiple_class_patches/patch_lib1.dart:9:7: Context: Previous declaration of 'Class'.
+// class Class {
+//       ^^^^^
+//
+import self as test;
+import "dart:_internal" as _in;
+import "dart:core" as core;
+
+import "dart:_internal";
+import "dart:_internal";
+
+@#C1
+class Class#1#1 extends core::Object { // from org-dartlang-testcase:///patch_lib2.dart
+  synthetic constructor •() → test::Class#1#1
+    : super core::Object::•()
+    ;
+  @#C1
+  method method2() → core::int
+    return 87;
+  @#C1
+  method method3() → core::int
+    return 123;
+}
+@#C1
+class Class extends core::Object {
+  synthetic constructor •() → test::Class
+    : super core::Object::•()
+    ;
+  @#C1
+  method /* from org-dartlang-testcase:///patch_lib1.dart */ method1() → core::int
+    return 42;
+  external method method2() → core::int;
+  @#C1
+  method /* from org-dartlang-testcase:///patch_lib1.dart */ method3() → core::int
+    return 321;
+}
+
+constants  {
+  #C1 = _in::_Patch {}
+}

pkg/front_end/testcases/general/multiple_class_patches/main.dart.weak.outline.expect

@@ -0,0 +1,59 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+
+import "dart:test";
+
+static method main() → dynamic
+  ;
+static method expect(dynamic expected, dynamic actual) → dynamic
+  ;
+
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/general/multiple_class_patches/patch_lib2.dart:9:7: Error: 'Class' is already declared in this scope.
+// class Class {
+//       ^^^^^
+// pkg/front_end/testcases/general/multiple_class_patches/patch_lib1.dart:9:7: Context: Previous declaration of 'Class'.
+// class Class {
+//       ^^^^^
+//
+import self as self2;
+import "dart:_internal" as _in;
+import "dart:core" as core;
+
+import "dart:_internal";
+import "dart:_internal";
+
+@_in::patch
+class Class#1#1 extends core::Object { // from org-dartlang-testcase:///patch_lib2.dart
+  synthetic constructor •() → self2::Class#1#1
+    ;
+  @_in::patch
+  method method2() → core::int
+    ;
+  @_in::patch
+  method method3() → core::int
+    ;
+}
+@_in::patch
+class Class extends core::Object {
+  synthetic constructor •() → self2::Class
+    ;
+  @_in::patch
+  external method method1() → core::int;
+  external method method2() → core::int;
+  @_in::patch
+  external method method3() → core::int;
+}
+
+
+Extra constant evaluation status:
+Evaluated: StaticGet @ org-dartlang-testcase:///patch_lib2.dart:8:2 -> InstanceConstant(const _Patch{})
+Evaluated: StaticGet @ org-dartlang-testcase:///patch_lib2.dart:10:4 -> InstanceConstant(const _Patch{})
+Evaluated: StaticGet @ org-dartlang-testcase:///patch_lib2.dart:13:4 -> InstanceConstant(const _Patch{})
+Evaluated: StaticGet @ org-dartlang-testcase:///origin_lib.dart:7:23 -> InstanceConstant(const _Patch{})
+Evaluated: StaticGet @ org-dartlang-testcase:///origin_lib.dart:8:20 -> InstanceConstant(const _Patch{})
+Evaluated: StaticGet @ (unknown position in org-dartlang-testcase:///origin_lib.dart) -> InstanceConstant(const _Patch{})
+Extra constant evaluation: evaluated: 6, effectively constant: 6

pkg/front_end/testcases/general/multiple_class_patches/main.dart.weak.transformed.expect

@@ -0,0 +1,66 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "dart:test" as test;
+import "dart:core" as core;
+
+import "dart:test";
+
+static method main() → dynamic {
+  test::Class c = new test::Class::•();
+  self::expect(42, c.{test::Class::method1}(){() → core::int});
+  self::expect(87, c.{test::Class::method2}(){() → core::int});
+  self::expect(123, c.{test::Class::method3}(){() → core::int});
+}
+static method expect(dynamic expected, dynamic actual) → dynamic {
+  if(!(expected =={core::Object::==}{(core::Object) → core::bool} actual)) {
+    throw "Expected ${expected}, actual ${actual}";
+  }
+}
+
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/general/multiple_class_patches/patch_lib2.dart:9:7: Error: 'Class' is already declared in this scope.
+// class Class {
+//       ^^^^^
+// pkg/front_end/testcases/general/multiple_class_patches/patch_lib1.dart:9:7: Context: Previous declaration of 'Class'.
+// class Class {
+//       ^^^^^
+//
+import self as test;
+import "dart:_internal" as _in;
+import "dart:core" as core;
+
+import "dart:_internal";
+import "dart:_internal";
+
+@#C1
+class Class#1#1 extends core::Object { // from org-dartlang-testcase:///patch_lib2.dart
+  synthetic constructor •() → test::Class#1#1
+    : super core::Object::•()
+    ;
+  @#C1
+  method method2() → core::int
+    return 87;
+  @#C1
+  method method3() → core::int
+    return 123;
+}
+@#C1
+class Class extends core::Object {
+  synthetic constructor •() → test::Class
+    : super core::Object::•()
+    ;
+  @#C1
+  method /* from org-dartlang-testcase:///patch_lib1.dart */ method1() → core::int
+    return 42;
+  external method method2() → core::int;
+  @#C1
+  method /* from org-dartlang-testcase:///patch_lib1.dart */ method3() → core::int
+    return 321;
+}
+
+constants  {
+  #C1 = _in::_Patch {}
+}

pkg/front_end/testcases/general/multiple_class_patches/origin_lib.dart

@@ -0,0 +1,9 @@
+// Copyright (c) 2022, 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 Class {
+  external int method1();
+  external int method2();
+  external int method3();
+}

pkg/front_end/testcases/general/multiple_class_patches/patch_lib1.dart

@@ -0,0 +1,15 @@
+// Copyright (c) 2022, 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.
+
+// ignore: import_internal_library
+import 'dart:_internal';
+
+@patch
+class Class {
+  @patch
+  int method1() => 42;
+
+  @patch
+  int method3() => 321;
+}

pkg/front_end/testcases/general/multiple_class_patches/patch_lib2.dart

@@ -0,0 +1,15 @@
+// Copyright (c) 2022, 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.
+
+// ignore: import_internal_library
+import 'dart:_internal';
+
+@patch
+class Class {
+  @patch
+  int method2() => 87;
+
+  @patch
+  int method3() => 123;
+}

pkg/front_end/testcases/macros/duplicate_augment.dart

@@ -0,0 +1,12 @@
+// Copyright (c) 2022, 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.
+
+import augment 'duplicate_augment_lib.dart';
+
+void augmentedTopLevelMethod() {}
+
+class AugmentedClass {
+  void augmentedInstanceMethod() {}
+  static void augmentedStaticMethod() {}
+}