feature/void

Sources/Fuzzilli/Base/ProgramBuilder.swift

@@ -2039,6 +2039,11 @@ public class ProgramBuilder {
         return emit(TypeOf(), withInputs: [v]).output
     }
 
+    @discardableResult
+    public func void(_ v: Variable) -> Variable {
+        return emit(Void_(), withInputs: [v]).output
+    }
+
     @discardableResult
     public func testInstanceOf(_ v: Variable, _ type: Variable) -> Variable {
         return emit(TestInstanceOf(), withInputs: [v, type]).output

Sources/Fuzzilli/CodeGen/CodeGeneratorWeights.swift

@@ -193,4 +193,5 @@ public let codeGeneratorWeights = [
     "ApiConstructorCallGenerator":              15,
     "ApiMethodCallGenerator":                   15,
     "ApiFunctionCallGenerator":                 15,
+    "VoidGenerator":                            1,
 ]

Sources/Fuzzilli/CodeGen/CodeGenerators.swift

@@ -974,6 +974,10 @@ public let CodeGenerators: [CodeGenerator] = [
         b.compare(type, with: rhs, using: .strictEqual)
     },
 
+    CodeGenerator("VoidGenerator", inputs: .one) { b, val in
+        b.void(val)
+    },
+
     CodeGenerator("InstanceOfGenerator", inputs: .preferred(.anything, .constructor())) { b, val, cls in
         b.testInstanceOf(val, cls)
     },

Sources/Fuzzilli/Compiler/Compiler.swift

@@ -1059,6 +1059,9 @@ public class JavaScriptCompiler {
             if unaryExpression.operator == "typeof" {
                 let argument = try compileExpression(unaryExpression.argument)
                 return emit(TypeOf(), withInputs: [argument]).output
+            } else if unaryExpression.operator == "void" {
+                let argument = try compileExpression(unaryExpression.argument)
+                return emit(Void_(), withInputs: [argument]).output
             } else if unaryExpression.operator == "delete" {
                 guard case .memberExpression(let memberExpression) = unaryExpression.argument.expression else {
                     throw CompilerError.invalidNodeError("delete operator must be applied to a member expression")

Sources/Fuzzilli/FuzzIL/Instruction.swift

@@ -565,6 +565,8 @@ extension Instruction: ProtobufConvertible {
                 }
             case .typeOf:
                 $0.typeOf = Fuzzilli_Protobuf_TypeOf()
+            case .void:
+                $0.void = Fuzzilli_Protobuf_Void()
             case .testInstanceOf:
                 $0.testInstanceOf = Fuzzilli_Protobuf_TestInstanceOf()
             case .testIn:
@@ -1042,6 +1044,8 @@ extension Instruction: ProtobufConvertible {
             op = ConfigureComputedProperty(flags: flags, type: try convertEnum(p.type, PropertyType.allCases))
         case .typeOf:
             op = TypeOf()
+        case .void:
+            op = Void_()
         case .testInstanceOf:
             op = TestInstanceOf()
         case .testIn:

Sources/Fuzzilli/FuzzIL/JSTyper.swift

@@ -676,6 +676,9 @@ public struct JSTyper: Analyzer {
         case .typeOf:
             set(instr.output, .string)
 
+        case .void:
+            set(instr.output, .undefined)
+
         case .testInstanceOf:
             set(instr.output, .boolean)
 

Sources/Fuzzilli/FuzzIL/JsOperations.swift

@@ -1030,6 +1030,14 @@ final class TypeOf: JsOperation {
     }
 }
 
+final class Void_: JsOperation {
+    override var opcode: Opcode { .void(self) }
+
+    init() {
+        super.init(numInputs: 1, numOutputs: 1)
+    }
+}
+
 final class TestInstanceOf: JsOperation {
     override var opcode: Opcode { .testInstanceOf(self) }
 

Sources/Fuzzilli/FuzzIL/Opcodes.swift

@@ -106,6 +106,7 @@ enum Opcode {
     case deleteComputedProperty(DeleteComputedProperty)
     case configureComputedProperty(ConfigureComputedProperty)
     case typeOf(TypeOf)
+    case void(Void_)
     case testInstanceOf(TestInstanceOf)
     case testIn(TestIn)
     case beginPlainFunction(BeginPlainFunction)

Sources/Fuzzilli/Lifting/FuzzILLifter.swift

@@ -366,6 +366,9 @@ public class FuzzILLifter: Lifter {
         case .typeOf:
             w.emit("\(output()) <- TypeOf \(input(0))")
 
+        case .void:
+            w.emit("\(output()) <- Void_ \(input(0))")
+
         case .testInstanceOf:
             w.emit("\(output()) <- TestInstanceOf \(input(0)), \(input(1))")
 

Sources/Fuzzilli/Lifting/JavaScriptLifter.swift

@@ -642,6 +642,10 @@ public class JavaScriptLifter: Lifter {
                 let expr = UnaryExpression.new() + "typeof " + input(0)
                 w.assign(expr, to: instr.output)
 
+            case .void:
+                let expr = UnaryExpression.new() + "void " + input(0)
+                w.assign(expr, to: instr.output)
+
             case .testInstanceOf:
                 let lhs = input(0)
                 let rhs = input(1)

Sources/Fuzzilli/Protobuf/operations.pb.swift

@@ -1,5 +1,6 @@
 // DO NOT EDIT.
 // swift-format-ignore-file
+// swiftlint:disable all
 //
 // Generated by the Swift generator plugin for the protocol buffer compiler.
 // Source: operations.proto
@@ -21,7 +22,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-import Foundation
 import SwiftProtobuf
 
 // If the compiler emits an error on this type, it is because this file
@@ -1278,6 +1278,16 @@ public struct Fuzzilli_Protobuf_TypeOf: Sendable {
   public init() {}
 }
 
+public struct Fuzzilli_Protobuf_Void: Sendable {
+  // SwiftProtobuf.Message conformance is added in an extension below. See the
+  // `Message` and `Message+*Additions` files in the SwiftProtobuf library for
+  // methods supported on all messages.
+
+  public var unknownFields = SwiftProtobuf.UnknownStorage()
+
+  public init() {}
+}
+
 public struct Fuzzilli_Protobuf_TestInstanceOf: Sendable {
   // SwiftProtobuf.Message conformance is added in an extension below. See the
   // `Message` and `Message+*Additions` files in the SwiftProtobuf library for
@@ -4885,6 +4895,25 @@ extension Fuzzilli_Protobuf_TypeOf: SwiftProtobuf.Message, SwiftProtobuf._Messag
   }
 }
 
+extension Fuzzilli_Protobuf_Void: SwiftProtobuf.Message, SwiftProtobuf._MessageImplementationBase, SwiftProtobuf._ProtoNameProviding {
+  public static let protoMessageName: String = _protobuf_package + ".Void"
+  public static let _protobuf_nameMap = SwiftProtobuf._NameMap()
+
+  public mutating func decodeMessage<D: SwiftProtobuf.Decoder>(decoder: inout D) throws {
+    // Load everything into unknown fields
+    while try decoder.nextFieldNumber() != nil {}
+  }
+
+  public func traverse<V: SwiftProtobuf.Visitor>(visitor: inout V) throws {
+    try unknownFields.traverse(visitor: &visitor)
+  }
+
+  public static func ==(lhs: Fuzzilli_Protobuf_Void, rhs: Fuzzilli_Protobuf_Void) -> Bool {
+    if lhs.unknownFields != rhs.unknownFields {return false}
+    return true
+  }
+}
+
 extension Fuzzilli_Protobuf_TestInstanceOf: SwiftProtobuf.Message, SwiftProtobuf._MessageImplementationBase, SwiftProtobuf._ProtoNameProviding {
   public static let protoMessageName: String = _protobuf_package + ".TestInstanceOf"
   public static let _protobuf_nameMap = SwiftProtobuf._NameMap()

Sources/Fuzzilli/Protobuf/operations.proto

@@ -337,6 +337,9 @@ message ConfigureComputedProperty {
 message TypeOf {
 }
 
+message Void {
+}
+
 message TestInstanceOf {
 }