[js_runtime] Add JsObject.safeToString via registered hook

Change-Id: Ic3f67e61f5f77b343082bb42c52b0c2b6d14eddc
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/423962
Commit-Queue: Stephen Adams <[email protected]>
Reviewed-by: Srujan Gaddam <[email protected]>

Author: rakudrama

pkg/compiler/test/rti/data/generic_methods_dynamic_05.dart

@@ -6,10 +6,10 @@ import 'package:compiler/src/util/testing.dart';
 
 // Test derived from language/generic_methods_dynamic_test/05
 
-/*spec.class: global#JSArray:deps=[ArrayIterator,List],explicit=[JSArray.E,JSArray<ArrayIterator.E>],implicit=[JSArray.E],needsArgs,test*/
-/*prod.class: global#JSArray:deps=[List],implicit=[JSArray.E],needsArgs,test*/
+/*spec.class: global#JSArray:deps=[ArrayIterator,List],explicit=[JSArray,JSArray.E,JSArray<ArrayIterator.E>],implicit=[JSArray.E],needsArgs,test*/
+/*prod.class: global#JSArray:deps=[List],explicit=[JSArray],implicit=[JSArray.E],needsArgs,test*/
 
-/*spec.class: global#List:deps=[C.bar,JSArray.markFixedList],explicit=[List,List<B>,List<Object>,List<Object?>,List<String>?,List<markFixedList.T>],needsArgs,test*/
+/*spec.class: global#List:deps=[C.bar,JSArray.markFixedList],explicit=[List,List<B>,List<Object>,List<Object?>,List<SafeToStringHook>,List<String>?,List<markFixedList.T>],needsArgs,test*/
 /*prod.class: global#List:deps=[C.bar],explicit=[List,List<B>],needsArgs,test*/
 
 class A {}

pkg/compiler/test/rti/data/list_literal.dart

@@ -2,11 +2,11 @@
 // 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.
 
-/*spec.class: global#List:deps=[Class.m,JSArray.markFixedList],explicit=[List,List<Object>,List<Object?>,List<String>?,List<markFixedList.T>],needsArgs,test*/
+/*spec.class: global#List:deps=[Class.m,JSArray.markFixedList],explicit=[List,List<Object>,List<Object?>,List<SafeToStringHook>,List<String>?,List<markFixedList.T>],needsArgs,test*/
 /*prod.class: global#List:deps=[Class.m],explicit=[List],needsArgs,test*/
 
-/*spec.class: global#JSArray:deps=[ArrayIterator,List],explicit=[JSArray.E,JSArray<ArrayIterator.E>],implicit=[JSArray.E],needsArgs,test*/
-/*prod.class: global#JSArray:deps=[List],implicit=[JSArray.E],needsArgs,test*/
+/*spec.class: global#JSArray:deps=[ArrayIterator,List],explicit=[JSArray,JSArray.E,JSArray<ArrayIterator.E>],implicit=[JSArray.E],needsArgs,test*/
+/*prod.class: global#JSArray:deps=[List],explicit=[JSArray],implicit=[JSArray.E],needsArgs,test*/
 
 main() {
   var c = Class();

pkg/compiler/test/rti/data/list_to_set.dart

@@ -2,11 +2,11 @@
 // 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.
 
-/*spec.class: global#List:deps=[Class,JSArray.markFixedList],explicit=[List,List<Object>,List<Object?>,List<String>?,List<markFixedList.T>],needsArgs,test*/
+/*spec.class: global#List:deps=[Class,JSArray.markFixedList],explicit=[List,List<Object>,List<Object?>,List<SafeToStringHook>,List<String>?,List<markFixedList.T>],needsArgs,test*/
 /*prod.class: global#List:deps=[Class],explicit=[List],needsArgs,test*/
 
-/*spec.class: global#JSArray:deps=[ArrayIterator,List],explicit=[JSArray.E,JSArray<ArrayIterator.E>],implicit=[JSArray.E],needsArgs,test*/
-/*prod.class: global#JSArray:deps=[List],implicit=[JSArray.E],needsArgs,test*/
+/*spec.class: global#JSArray:deps=[ArrayIterator,List],explicit=[JSArray,JSArray.E,JSArray<ArrayIterator.E>],implicit=[JSArray.E],needsArgs,test*/
+/*prod.class: global#JSArray:deps=[List],explicit=[JSArray],implicit=[JSArray.E],needsArgs,test*/
 
 main() {
   var c = Class<int>();

pkg/compiler/test/rti/data/local_function_list_literal.dart

@@ -4,8 +4,8 @@
 
 import 'package:compiler/src/util/testing.dart';
 
-/*spec.class: global#JSArray:deps=[ArrayIterator,List],explicit=[JSArray.E,JSArray<ArrayIterator.E>],implicit=[JSArray.E],needsArgs,test*/
-/*prod.class: global#JSArray:deps=[List],implicit=[JSArray.E],needsArgs,test*/
+/*spec.class: global#JSArray:deps=[ArrayIterator,List],explicit=[JSArray,JSArray.E,JSArray<ArrayIterator.E>],implicit=[JSArray.E],needsArgs,test*/
+/*prod.class: global#JSArray:deps=[List],explicit=[JSArray],implicit=[JSArray.E],needsArgs,test*/
 
 @pragma('dart2js:noInline')
 /*member: method:implicit=[method.T],needsArgs,test*/

sdk/lib/_internal/js_runtime/lib/interceptors.dart

@@ -51,6 +51,7 @@ import 'dart:_js_helper'
         lookupAndCacheInterceptor,
         StringMatch,
         firstMatchAfter,
+        SafeToStringHook,
         TrustedGetRuntimeType;
 
 import 'dart:_foreign_helper'

sdk/lib/_internal/js_runtime/lib/js_array.dart

@@ -855,6 +855,26 @@ class JSArray<E> extends JavaScriptObject implements List<E>, JSIndexable<E> {
   Type get runtimeType => getRuntimeTypeOfArray(this);
 }
 
+class JSArraySafeToStringHook extends SafeToStringHook {
+  const JSArraySafeToStringHook();
+  String? tryFormat(Object? array) {
+    if (array is! JSArray) return null;
+
+    final int flags = HArrayFlagsGet(array);
+    String info = '';
+    if (flags & ArrayFlags.constantCheck != 0) {
+      info = 'const, ';
+    } else if (flags & ArrayFlags.unmodifiableCheck != 0) {
+      info = 'unmodifiable, ';
+    } else if (flags & ArrayFlags.fixedLengthCheck != 0) {
+      info = 'fixed, ';
+    }
+    final base = Primitives.objectToHumanReadableString(array);
+    if (info == '') return base;
+    return '$base (${info}length: ${array.length})';
+  }
+}
+
 /// Dummy subclasses that allow the backend to track more precise
 /// information about arrays through their type. The CPA type inference
 /// relies on the fact that these classes do not override [] nor []=.