Shape Number/%TypedArray% constructors and %TypedArray%.prototype; add [JsInstanceSlot]

Jint.Benchmark/BuiltinShapeBenchmark.cs

@@ -102,7 +102,8 @@ public Engine EngineInitGenerators()
         + "Intl.DateTimeFormat.prototype.resolvedOptions; Intl.NumberFormat.prototype.resolvedOptions;"
         + "Array.prototype.map; Number.prototype.toFixed; Boolean.prototype.valueOf; Error.prototype.toString;"
         + "[].values().next; new Map().keys().next; new Set().values().next; ''[Symbol.iterator]().next;"
-        + "String.prototype.slice; Date.prototype.getTime; Set.prototype.union; RegExp.prototype.test;");
+        + "String.prototype.slice; Date.prototype.getTime; Set.prototype.union; RegExp.prototype.test;"
+        + "Uint8Array.prototype.join;");
 
     [Benchmark]
     public Engine EngineInitPrototypes()
@@ -122,7 +123,8 @@ public Engine EngineInitPrototypes()
         + "Temporal.PlainTime.from; Temporal.PlainYearMonth.from; Temporal.PlainMonthDay.from; Temporal.ZonedDateTime.from;"
         + "Intl.NumberFormat.supportedLocalesOf; Intl.Collator.supportedLocalesOf; Intl.DateTimeFormat.supportedLocalesOf;"
         + "Intl.ListFormat.supportedLocalesOf; Intl.PluralRules.supportedLocalesOf; Intl.RelativeTimeFormat.supportedLocalesOf;"
-        + "Intl.Segmenter.supportedLocalesOf; Intl.DisplayNames.supportedLocalesOf; Intl.DurationFormat.supportedLocalesOf;");
+        + "Intl.Segmenter.supportedLocalesOf; Intl.DisplayNames.supportedLocalesOf; Intl.DurationFormat.supportedLocalesOf;"
+        + "Number.parseInt; Int8Array.from;");
 
     [Benchmark]
     public Engine EngineInitConstructors()

Jint.SourceGenerators/Attributes.cs

@@ -217,5 +217,18 @@ public JsAliasAttribute(string name, string target)
             public string Target { get; }
         }
 
+        // Class-level, repeats. Reserves a per-realm own-property slot (appended after all other own
+        // properties, matching a hand-written SetProperty/AddDangerous tail) that the host fills in
+        // Initialize via SetBuiltinSlotByName(name, descriptor) — for a computed/lazy value the generator
+        // can't express, e.g. %TypedArray%.prototype.toString aliasing %Array.prototype.toString% lazily.
+        // Shape hosts only (a non-shaped host just SetProperty()s the value in Initialize as before).
+        [global::System.AttributeUsage(global::System.AttributeTargets.Class, AllowMultiple = true)]
+        [global::System.Diagnostics.Conditional("JINT_SOURCE_GENERATORS")]
+        internal sealed class JsInstanceSlotAttribute : global::System.Attribute
+        {
+            public JsInstanceSlotAttribute(string name) { Name = name; }
+            public string Name { get; }
+        }
+
         """;
 }

Jint.SourceGenerators/Emitter.cs

@@ -131,6 +131,7 @@ private static IEnumerable<string> EnumerateAllJsNames(ObjectDefinition obj, IRe
         foreach (var name in accessorsByName.Keys) yield return name;
         foreach (var thr in obj.ThrowerAccessors) yield return thr.JsName;
         foreach (var a in obj.Aliases) yield return a.Name;
+        foreach (var s in obj.InstanceSlots) yield return s;
     }
 
     /// <summary>
@@ -360,7 +361,7 @@ string SlotExpr(FunctionDefinition? fn) => fn is null
         sb.AppendLine();
         sb.AppendLine("    private static global::Jint.Native.Object.BuiltinShape BuildBuiltinShape_Generated()");
         sb.AppendLine("    {");
-        sb.Append("        var builder = new global::Jint.Native.Object.BuiltinShape.Builder(").Append(obj.Properties.Count + dataProperties.Count + accessorsByName.Count + obj.Aliases.Count).AppendLine(");");
+        sb.Append("        var builder = new global::Jint.Native.Object.BuiltinShape.Builder(").Append(obj.Properties.Count + dataProperties.Count + accessorsByName.Count + obj.Aliases.Count + obj.InstanceSlots.Count).AppendLine(");");
         // Order matches the dictionary path: properties, then functions, then accessors (each sorted by JsName).
         // Static-immutable constants share a process-wide descriptor; other properties are per-realm instance slots.
         foreach (var prop in obj.Properties)
@@ -394,6 +395,11 @@ string SlotExpr(FunctionDefinition? fn) => fn is null
         {
             sb.Append("        builder.Alias(__Key_").Append(SanitizeIdentifier(alias.Name)).Append(", __Key_").Append(SanitizeIdentifier(alias.Target)).AppendLine(");");
         }
+        // Host-filled instance slots last (the host supplies the descriptor in Initialize via SetBuiltinSlotByName).
+        foreach (var slot in obj.InstanceSlots)
+        {
+            sb.Append("        builder.Instance(__Key_").Append(SanitizeIdentifier(slot)).AppendLine(");");
+        }
         sb.AppendLine("        return builder.Build();");
         sb.AppendLine("    }");
         sb.AppendLine();

Jint.SourceGenerators/Models.cs

@@ -41,6 +41,7 @@ internal sealed record class ObjectDefinition(
     EquatableArray<ThrowerAccessorDefinition> ThrowerAccessors,
     EquatableArray<IntrinsicReferenceDefinition> IntrinsicReferences,
     EquatableArray<AliasDefinition> Aliases,
+    EquatableArray<string> InstanceSlots,
     EquatableArray<DiagnosticInfo> DiagnosticInfos)
 {
     public string HintName => string.IsNullOrEmpty(Namespace)
@@ -138,6 +139,7 @@ public IEnumerable<Diagnostic> Diagnostics
         var throwerAccessors = new List<ThrowerAccessorDefinition>();
         var intrinsicReferences = new List<IntrinsicReferenceDefinition>();
         var aliases = new List<AliasDefinition>();
+        var instanceSlots = new List<string>();
         HashSet<string>? seenFunctionClrNames = null;
         HashSet<string>? seenThrowerNames = null;
         HashSet<string>? seenIntrinsicReferenceNames = null;
@@ -206,6 +208,16 @@ public IEnumerable<Diagnostic> Diagnostics
             aliases.Add(new AliasDefinition(aliasName!, aliasTarget!));
         }
 
+        // Class-level [JsInstanceSlot("name")] — a host-filled reserved slot (shape path only).
+        foreach (var attr in typeSymbol.GetAttributes())
+        {
+            if (attr.AttributeClass?.Name != "JsInstanceSlotAttribute") continue;
+            if (attr.ConstructorArguments.Length == 0) continue;
+            var slotName = attr.ConstructorArguments[0].Value as string;
+            if (string.IsNullOrWhiteSpace(slotName)) continue;
+            instanceSlots.Add(slotName!);
+        }
+
         foreach (var member in typeSymbol.GetMembers())
         {
             ct.ThrowIfCancellationRequested();
@@ -397,6 +409,7 @@ public IEnumerable<Diagnostic> Diagnostics
             ThrowerAccessors: throwerAccessors.ToEquatableArray(),
             IntrinsicReferences: intrinsicReferences.ToEquatableArray(),
             Aliases: aliases.ToEquatableArray(),
+            InstanceSlots: instanceSlots.ToEquatableArray(),
             DiagnosticInfos: diagnostics.ToEquatableArray());
     }
 

Jint.Tests.SourceGenerators/Snapshots/ObjectGeneratorTests.AccessorGetterAndSetter#JintAttributes.g.verified.cs

@@ -212,3 +212,16 @@ public JsAliasAttribute(string name, string target)
     public string Name { get; }
     public string Target { get; }
 }
+
+// Class-level, repeats. Reserves a per-realm own-property slot (appended after all other own
+// properties, matching a hand-written SetProperty/AddDangerous tail) that the host fills in
+// Initialize via SetBuiltinSlotByName(name, descriptor) — for a computed/lazy value the generator
+// can't express, e.g. %TypedArray%.prototype.toString aliasing %Array.prototype.toString% lazily.
+// Shape hosts only (a non-shaped host just SetProperty()s the value in Initialize as before).
+[global::System.AttributeUsage(global::System.AttributeTargets.Class, AllowMultiple = true)]
+[global::System.Diagnostics.Conditional("JINT_SOURCE_GENERATORS")]
+internal sealed class JsInstanceSlotAttribute : global::System.Attribute
+{
+    public JsInstanceSlotAttribute(string name) { Name = name; }
+    public string Name { get; }
+}

Jint.Tests.SourceGenerators/Snapshots/ObjectGeneratorTests.AccessorGetterOnly#JintAttributes.g.verified.cs

@@ -212,3 +212,16 @@ public JsAliasAttribute(string name, string target)
     public string Name { get; }
     public string Target { get; }
 }
+
+// Class-level, repeats. Reserves a per-realm own-property slot (appended after all other own
+// properties, matching a hand-written SetProperty/AddDangerous tail) that the host fills in
+// Initialize via SetBuiltinSlotByName(name, descriptor) — for a computed/lazy value the generator
+// can't express, e.g. %TypedArray%.prototype.toString aliasing %Array.prototype.toString% lazily.
+// Shape hosts only (a non-shaped host just SetProperty()s the value in Initialize as before).
+[global::System.AttributeUsage(global::System.AttributeTargets.Class, AllowMultiple = true)]
+[global::System.Diagnostics.Conditional("JINT_SOURCE_GENERATORS")]
+internal sealed class JsInstanceSlotAttribute : global::System.Attribute
+{
+    public JsInstanceSlotAttribute(string name) { Name = name; }
+    public string Name { get; }
+}

Jint.Tests.SourceGenerators/Snapshots/ObjectGeneratorTests.AccessorWrongArity_ProducesDiagnostic#JintAttributes.g.verified.cs

@@ -212,3 +212,16 @@ public JsAliasAttribute(string name, string target)
     public string Name { get; }
     public string Target { get; }
 }
+
+// Class-level, repeats. Reserves a per-realm own-property slot (appended after all other own
+// properties, matching a hand-written SetProperty/AddDangerous tail) that the host fills in
+// Initialize via SetBuiltinSlotByName(name, descriptor) — for a computed/lazy value the generator
+// can't express, e.g. %TypedArray%.prototype.toString aliasing %Array.prototype.toString% lazily.
+// Shape hosts only (a non-shaped host just SetProperty()s the value in Initialize as before).
+[global::System.AttributeUsage(global::System.AttributeTargets.Class, AllowMultiple = true)]
+[global::System.Diagnostics.Conditional("JINT_SOURCE_GENERATORS")]
+internal sealed class JsInstanceSlotAttribute : global::System.Attribute
+{
+    public JsInstanceSlotAttribute(string name) { Name = name; }
+    public string Name { get; }
+}

Jint.Tests.SourceGenerators/Snapshots/ObjectGeneratorTests.CoercedRestSpan#JintAttributes.g.verified.cs

@@ -212,3 +212,16 @@ public JsAliasAttribute(string name, string target)
     public string Name { get; }
     public string Target { get; }
 }
+
+// Class-level, repeats. Reserves a per-realm own-property slot (appended after all other own
+// properties, matching a hand-written SetProperty/AddDangerous tail) that the host fills in
+// Initialize via SetBuiltinSlotByName(name, descriptor) — for a computed/lazy value the generator
+// can't express, e.g. %TypedArray%.prototype.toString aliasing %Array.prototype.toString% lazily.
+// Shape hosts only (a non-shaped host just SetProperty()s the value in Initialize as before).
+[global::System.AttributeUsage(global::System.AttributeTargets.Class, AllowMultiple = true)]
+[global::System.Diagnostics.Conditional("JINT_SOURCE_GENERATORS")]
+internal sealed class JsInstanceSlotAttribute : global::System.Attribute
+{
+    public JsInstanceSlotAttribute(string name) { Name = name; }
+    public string Name { get; }
+}

Jint.Tests.SourceGenerators/Snapshots/ObjectGeneratorTests.CoercedRestSpanTypeMismatch_ProducesDiagnostic#JintAttributes.g.verified.cs

@@ -212,3 +212,16 @@ public JsAliasAttribute(string name, string target)
     public string Name { get; }
     public string Target { get; }
 }
+
+// Class-level, repeats. Reserves a per-realm own-property slot (appended after all other own
+// properties, matching a hand-written SetProperty/AddDangerous tail) that the host fills in
+// Initialize via SetBuiltinSlotByName(name, descriptor) — for a computed/lazy value the generator
+// can't express, e.g. %TypedArray%.prototype.toString aliasing %Array.prototype.toString% lazily.
+// Shape hosts only (a non-shaped host just SetProperty()s the value in Initialize as before).
+[global::System.AttributeUsage(global::System.AttributeTargets.Class, AllowMultiple = true)]
+[global::System.Diagnostics.Conditional("JINT_SOURCE_GENERATORS")]
+internal sealed class JsInstanceSlotAttribute : global::System.Attribute
+{
+    public JsInstanceSlotAttribute(string name) { Name = name; }
+    public string Name { get; }
+}

Jint.Tests.SourceGenerators/Snapshots/ObjectGeneratorTests.ConflictingAccessorFlags_ProducesDiagnostic#JintAttributes.g.verified.cs

@@ -212,3 +212,16 @@ public JsAliasAttribute(string name, string target)
     public string Name { get; }
     public string Target { get; }
 }
+
+// Class-level, repeats. Reserves a per-realm own-property slot (appended after all other own
+// properties, matching a hand-written SetProperty/AddDangerous tail) that the host fills in
+// Initialize via SetBuiltinSlotByName(name, descriptor) — for a computed/lazy value the generator
+// can't express, e.g. %TypedArray%.prototype.toString aliasing %Array.prototype.toString% lazily.
+// Shape hosts only (a non-shaped host just SetProperty()s the value in Initialize as before).
+[global::System.AttributeUsage(global::System.AttributeTargets.Class, AllowMultiple = true)]
+[global::System.Diagnostics.Conditional("JINT_SOURCE_GENERATORS")]
+internal sealed class JsInstanceSlotAttribute : global::System.Attribute
+{
+    public JsInstanceSlotAttribute(string name) { Name = name; }
+    public string Name { get; }
+}

Jint.Tests.SourceGenerators/Snapshots/ObjectGeneratorTests.ConflictingConversionAttrs_ProducesDiagnostic#JintAttributes.g.verified.cs

@@ -212,3 +212,16 @@ public JsAliasAttribute(string name, string target)
     public string Name { get; }
     public string Target { get; }
 }
+
+// Class-level, repeats. Reserves a per-realm own-property slot (appended after all other own
+// properties, matching a hand-written SetProperty/AddDangerous tail) that the host fills in
+// Initialize via SetBuiltinSlotByName(name, descriptor) — for a computed/lazy value the generator
+// can't express, e.g. %TypedArray%.prototype.toString aliasing %Array.prototype.toString% lazily.
+// Shape hosts only (a non-shaped host just SetProperty()s the value in Initialize as before).
+[global::System.AttributeUsage(global::System.AttributeTargets.Class, AllowMultiple = true)]
+[global::System.Diagnostics.Conditional("JINT_SOURCE_GENERATORS")]
+internal sealed class JsInstanceSlotAttribute : global::System.Attribute
+{
+    public JsInstanceSlotAttribute(string name) { Name = name; }
+    public string Name { get; }
+}

Jint.Tests.SourceGenerators/Snapshots/ObjectGeneratorTests.ConversionTypeMismatch_ProducesDiagnostic#JintAttributes.g.verified.cs

@@ -212,3 +212,16 @@ public JsAliasAttribute(string name, string target)
     public string Name { get; }
     public string Target { get; }
 }
+
+// Class-level, repeats. Reserves a per-realm own-property slot (appended after all other own
+// properties, matching a hand-written SetProperty/AddDangerous tail) that the host fills in
+// Initialize via SetBuiltinSlotByName(name, descriptor) — for a computed/lazy value the generator
+// can't express, e.g. %TypedArray%.prototype.toString aliasing %Array.prototype.toString% lazily.
+// Shape hosts only (a non-shaped host just SetProperty()s the value in Initialize as before).
+[global::System.AttributeUsage(global::System.AttributeTargets.Class, AllowMultiple = true)]
+[global::System.Diagnostics.Conditional("JINT_SOURCE_GENERATORS")]
+internal sealed class JsInstanceSlotAttribute : global::System.Attribute
+{
+    public JsInstanceSlotAttribute(string name) { Name = name; }
+    public string Name { get; }
+}

Jint.Tests.SourceGenerators/Snapshots/ObjectGeneratorTests.DuplicateIntrinsicReference_ProducesDiagnostic#JintAttributes.g.verified.cs

@@ -212,3 +212,16 @@ public JsAliasAttribute(string name, string target)
     public string Name { get; }
     public string Target { get; }
 }
+
+// Class-level, repeats. Reserves a per-realm own-property slot (appended after all other own
+// properties, matching a hand-written SetProperty/AddDangerous tail) that the host fills in
+// Initialize via SetBuiltinSlotByName(name, descriptor) — for a computed/lazy value the generator
+// can't express, e.g. %TypedArray%.prototype.toString aliasing %Array.prototype.toString% lazily.
+// Shape hosts only (a non-shaped host just SetProperty()s the value in Initialize as before).
+[global::System.AttributeUsage(global::System.AttributeTargets.Class, AllowMultiple = true)]
+[global::System.Diagnostics.Conditional("JINT_SOURCE_GENERATORS")]
+internal sealed class JsInstanceSlotAttribute : global::System.Attribute
+{
+    public JsInstanceSlotAttribute(string name) { Name = name; }
+    public string Name { get; }
+}

Jint.Tests.SourceGenerators/Snapshots/ObjectGeneratorTests.DuplicateThrower_ProducesDiagnostic#JintAttributes.g.verified.cs

@@ -212,3 +212,16 @@ public JsAliasAttribute(string name, string target)
     public string Name { get; }
     public string Target { get; }
 }
+
+// Class-level, repeats. Reserves a per-realm own-property slot (appended after all other own
+// properties, matching a hand-written SetProperty/AddDangerous tail) that the host fills in
+// Initialize via SetBuiltinSlotByName(name, descriptor) — for a computed/lazy value the generator
+// can't express, e.g. %TypedArray%.prototype.toString aliasing %Array.prototype.toString% lazily.
+// Shape hosts only (a non-shaped host just SetProperty()s the value in Initialize as before).
+[global::System.AttributeUsage(global::System.AttributeTargets.Class, AllowMultiple = true)]
+[global::System.Diagnostics.Conditional("JINT_SOURCE_GENERATORS")]
+internal sealed class JsInstanceSlotAttribute : global::System.Attribute
+{
+    public JsInstanceSlotAttribute(string name) { Name = name; }
+    public string Name { get; }
+}

Jint.Tests.SourceGenerators/Snapshots/ObjectGeneratorTests.InstanceMethod#JintAttributes.g.verified.cs

@@ -212,3 +212,16 @@ public JsAliasAttribute(string name, string target)
     public string Name { get; }
     public string Target { get; }
 }
+
+// Class-level, repeats. Reserves a per-realm own-property slot (appended after all other own
+// properties, matching a hand-written SetProperty/AddDangerous tail) that the host fills in
+// Initialize via SetBuiltinSlotByName(name, descriptor) — for a computed/lazy value the generator
+// can't express, e.g. %TypedArray%.prototype.toString aliasing %Array.prototype.toString% lazily.
+// Shape hosts only (a non-shaped host just SetProperty()s the value in Initialize as before).
+[global::System.AttributeUsage(global::System.AttributeTargets.Class, AllowMultiple = true)]
+[global::System.Diagnostics.Conditional("JINT_SOURCE_GENERATORS")]
+internal sealed class JsInstanceSlotAttribute : global::System.Attribute
+{
+    public JsInstanceSlotAttribute(string name) { Name = name; }
+    public string Name { get; }
+}

Jint.Tests.SourceGenerators/Snapshots/ObjectGeneratorTests.IntegerConversions#JintAttributes.g.verified.cs

@@ -212,3 +212,16 @@ public JsAliasAttribute(string name, string target)
     public string Name { get; }
     public string Target { get; }
 }
+
+// Class-level, repeats. Reserves a per-realm own-property slot (appended after all other own
+// properties, matching a hand-written SetProperty/AddDangerous tail) that the host fills in
+// Initialize via SetBuiltinSlotByName(name, descriptor) — for a computed/lazy value the generator
+// can't express, e.g. %TypedArray%.prototype.toString aliasing %Array.prototype.toString% lazily.
+// Shape hosts only (a non-shaped host just SetProperty()s the value in Initialize as before).
+[global::System.AttributeUsage(global::System.AttributeTargets.Class, AllowMultiple = true)]
+[global::System.Diagnostics.Conditional("JINT_SOURCE_GENERATORS")]
+internal sealed class JsInstanceSlotAttribute : global::System.Attribute
+{
+    public JsInstanceSlotAttribute(string name) { Name = name; }
+    public string Name { get; }
+}

Jint.Tests.SourceGenerators/Snapshots/ObjectGeneratorTests.IntrinsicReference#JintAttributes.g.verified.cs

@@ -212,3 +212,16 @@ public JsAliasAttribute(string name, string target)
     public string Name { get; }
     public string Target { get; }
 }
+
+// Class-level, repeats. Reserves a per-realm own-property slot (appended after all other own
+// properties, matching a hand-written SetProperty/AddDangerous tail) that the host fills in
+// Initialize via SetBuiltinSlotByName(name, descriptor) — for a computed/lazy value the generator
+// can't express, e.g. %TypedArray%.prototype.toString aliasing %Array.prototype.toString% lazily.
+// Shape hosts only (a non-shaped host just SetProperty()s the value in Initialize as before).
+[global::System.AttributeUsage(global::System.AttributeTargets.Class, AllowMultiple = true)]
+[global::System.Diagnostics.Conditional("JINT_SOURCE_GENERATORS")]
+internal sealed class JsInstanceSlotAttribute : global::System.Attribute
+{
+    public JsInstanceSlotAttribute(string name) { Name = name; }
+    public string Name { get; }
+}

Jint.Tests.SourceGenerators/Snapshots/ObjectGeneratorTests.IntrinsicReferenceWithoutRealmField_ProducesDiagnostic#JintAttributes.g.verified.cs

@@ -212,3 +212,16 @@ public JsAliasAttribute(string name, string target)
     public string Name { get; }
     public string Target { get; }
 }
+
+// Class-level, repeats. Reserves a per-realm own-property slot (appended after all other own
+// properties, matching a hand-written SetProperty/AddDangerous tail) that the host fills in
+// Initialize via SetBuiltinSlotByName(name, descriptor) — for a computed/lazy value the generator
+// can't express, e.g. %TypedArray%.prototype.toString aliasing %Array.prototype.toString% lazily.
+// Shape hosts only (a non-shaped host just SetProperty()s the value in Initialize as before).
+[global::System.AttributeUsage(global::System.AttributeTargets.Class, AllowMultiple = true)]
+[global::System.Diagnostics.Conditional("JINT_SOURCE_GENERATORS")]
+internal sealed class JsInstanceSlotAttribute : global::System.Attribute
+{
+    public JsInstanceSlotAttribute(string name) { Name = name; }
+    public string Name { get; }
+}