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  ** Copyright (C) 2016 The Qt Company Ltd.
  ** Contact: https://www.qt.io/licensing/
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  ** This file is part of the QtQml module of the Qt Toolkit.
  **
  ** $QT_BEGIN_LICENSE:LGPL$
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  ** accordance with the commercial license agreement provided with the
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  ** Alternatively, this file may be used under the terms of the GNU Lesser
  ** General Public License version 3 as published by the Free Software
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  ** packaging of this file. Please review the following information to
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  ** Alternatively, this file may be used under the terms of the GNU
  ** General Public License version 2.0 or (at your option) the GNU General
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  ****************************************************************************/
  #ifndef QV4FUNCTIONOBJECT_H
  #define QV4FUNCTIONOBJECT_H
  
  //
  //  W A R N I N G
  //  -------------
  //
  // This file is not part of the Qt API.  It exists purely as an
  // implementation detail.  This header file may change from version to
  // version without notice, or even be removed.
  //
  // We mean it.
  //
  
  #include "qv4object_p.h"
  #include "qv4function_p.h"
  #include "qv4context_p.h"
  #include <private/qv4mm_p.h>
  
  QT_BEGIN_NAMESPACE
  
  struct QQmlSourceLocation;
  
  namespace QV4 {
  
  struct IndexedBuiltinFunction;
  struct JSCallData;
  
  namespace Heap {
  
  
  #define FunctionObjectMembers(class, Member) \
      Member(class, Pointer, ExecutionContext *, scope) \
      Member(class, NoMark, Function *, function) \
      Member(class, NoMark, VTable::Call, jsCall) \
      Member(class, NoMark, VTable::CallAsConstructor, jsConstruct) \
      Member(class, NoMark, bool, canBeTailCalled)
  
  DECLARE_HEAP_OBJECT(FunctionObject, Object) {
      DECLARE_MARKOBJECTS(FunctionObject);
      enum {
          Index_ProtoConstructor = 0,
          Index_Prototype = 0,
          Index_HasInstance = 1,
      };
  
      bool isConstructor() const {
          return jsConstruct != nullptr;
      }
  
      Q_QML_PRIVATE_EXPORT void init(QV4::ExecutionContext *scope, QV4::String *name, VTable::Call call);
      Q_QML_PRIVATE_EXPORT void init(QV4::ExecutionContext *scope, QV4::String *name = nullptr);
      Q_QML_PRIVATE_EXPORT void init(QV4::ExecutionContext *scope, QV4::Function *function, QV4::String *n = nullptr);
      Q_QML_PRIVATE_EXPORT void init(QV4::ExecutionContext *scope, const QString &name);
      Q_QML_PRIVATE_EXPORT void init();
      Q_QML_PRIVATE_EXPORT void destroy();
  
      void setFunction(Function *f);
  
      unsigned int formalParameterCount() { return function ? function->nFormals : 0; }
      unsigned int varCount() { return function ? function->compiledFunction->nLocals : 0; }
  };
  
  struct FunctionCtor : FunctionObject {
      void init(QV4::ExecutionContext *scope);
  };
  
  struct FunctionPrototype : FunctionObject {
      void init();
  };
  
  struct IndexedBuiltinFunction : FunctionObject {
      inline void init(QV4::ExecutionContext *scope, uint index, VTable::Call call);
      uint index;
  };
  
  struct ArrowFunction : FunctionObject {
      enum {
          Index_Name = Index_HasInstance + 1,
          Index_Length
      };
      void init(QV4::ExecutionContext *scope, Function *function, QV4::String *name = nullptr);
  };
  
  #define ScriptFunctionMembers(class, Member) \
      Member(class, Pointer, InternalClass *, cachedClassForConstructor)
  
  DECLARE_HEAP_OBJECT(ScriptFunction, ArrowFunction) {
      DECLARE_MARKOBJECTS(ScriptFunction)
      void init(QV4::ExecutionContext *scope, Function *function);
  };
  
  #define MemberFunctionMembers(class, Member) \
      Member(class, Pointer, Object *, homeObject)
  
  DECLARE_HEAP_OBJECT(MemberFunction, ArrowFunction) {
      DECLARE_MARKOBJECTS(MemberFunction)
  
      void init(QV4::ExecutionContext *scope, Function *function, QV4::String *name = nullptr) {
          ArrowFunction::init(scope, function, name);
      }
  };
  
  #define ConstructorFunctionMembers(class, Member) \
      Member(class, Pointer, Object *, homeObject)
  
  DECLARE_HEAP_OBJECT(ConstructorFunction, ScriptFunction) {
      DECLARE_MARKOBJECTS(ConstructorFunction)
      bool isDerivedConstructor;
  };
  
  struct DefaultClassConstructorFunction : FunctionObject
  {
      bool isDerivedConstructor;
  };
  
  #define BoundFunctionMembers(class, Member) \
      Member(class, Pointer, FunctionObject *, target) \
      Member(class, HeapValue, HeapValue, boundThis) \
      Member(class, Pointer, MemberData *, boundArgs)
  
  DECLARE_HEAP_OBJECT(BoundFunction, FunctionObject) {
      DECLARE_MARKOBJECTS(BoundFunction);
  
      void init(QV4::ExecutionContext *scope, QV4::FunctionObject *target, const Value &boundThis, QV4::MemberData *boundArgs);
  };
  
  }
  
  struct Q_QML_EXPORT FunctionObject: Object {
      enum {
          IsFunctionObject = true
      };
      V4_OBJECT2(FunctionObject, Object)
      Q_MANAGED_TYPE(FunctionObject)
      V4_INTERNALCLASS(FunctionObject)
      V4_PROTOTYPE(functionPrototype)
      V4_NEEDS_DESTROY
      enum { NInlineProperties = 1 };
  
      bool canBeTailCalled() const { return d()->canBeTailCalled; }
      Heap::ExecutionContext *scope() const { return d()->scope; }
      Function *function() const { return d()->function; }
  
      ReturnedValue name() const;
      unsigned int formalParameterCount() const { return d()->formalParameterCount(); }
      unsigned int varCount() const { return d()->varCount(); }
  
      void setName(String *name) {
          defineReadonlyConfigurableProperty(engine()->id_name(), *name);
      }
      void createDefaultPrototypeProperty(uint protoConstructorSlot);
  
      inline ReturnedValue callAsConstructor(const JSCallData &data) const;
      ReturnedValue callAsConstructor(const Value *argv, int argc, const Value *newTarget = nullptr) const {
          if (!d()->jsConstruct)
              return engine()->throwTypeError(QStringLiteral("Function is not a constructor."));
          return d()->jsConstruct(this, argv, argc, newTarget ? newTarget : this);
      }
      inline ReturnedValue call(const JSCallData &data) const;
      ReturnedValue call(const Value *thisObject, const Value *argv, int argc) const {
          if (!d()->jsCall)
              return engine()->throwTypeError(QStringLiteral("Function can only be called with |new|."));
          return d()->jsCall(this, thisObject, argv, argc);
      }
      static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
  
      static Heap::FunctionObject *createScriptFunction(ExecutionContext *scope, Function *function);
      static Heap::FunctionObject *createConstructorFunction(ExecutionContext *scope, Function *function, Object *homeObject, bool isDerivedConstructor);
      static Heap::FunctionObject *createMemberFunction(ExecutionContext *scope, Function *function, Object *homeObject, String *name);
      static Heap::FunctionObject *createBuiltinFunction(ExecutionEngine *engine, StringOrSymbol *nameOrSymbol, VTable::Call code, int argumentCount);
  
      bool strictMode() const { return d()->function ? d()->function->isStrict() : false; }
      bool isBinding() const;
      bool isBoundFunction() const;
      bool isConstructor() const {
          return d()->isConstructor();
      }
  
      ReturnedValue getHomeObject() const;
  
      ReturnedValue protoProperty() const {
          return getValueByIndex(Heap::FunctionObject::Index_Prototype);
      }
      bool hasHasInstanceProperty() const {
          return !internalClass()->propertyData.at(Heap::FunctionObject::Index_HasInstance).isEmpty();
      }
  
      QQmlSourceLocation sourceLocation() const;
  };
  
  template<>
  inline const FunctionObject *Value::as() const {
      return isManaged() && m()->internalClass->vtable->isFunctionObject ? reinterpret_cast<const FunctionObject *>(this) : nullptr;
  }
  
  
  struct FunctionCtor: FunctionObject
  {
      V4_OBJECT2(FunctionCtor, FunctionObject)
  
      static ReturnedValue virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *);
      static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
  protected:
      enum Type {
          Type_Function,
          Type_Generator
      };
      static QQmlRefPointer<ExecutableCompilationUnit> parse(ExecutionEngine *engine, const Value *argv, int argc, Type t = Type_Function);
  };
  
  struct FunctionPrototype: FunctionObject
  {
      V4_OBJECT2(FunctionPrototype, FunctionObject)
  
      void init(ExecutionEngine *engine, Object *ctor);
  
      static ReturnedValue method_toString(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
      static ReturnedValue method_apply(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
      static ReturnedValue method_call(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
      static ReturnedValue method_bind(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
      static ReturnedValue method_hasInstance(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
  };
  
  struct Q_QML_PRIVATE_EXPORT IndexedBuiltinFunction : FunctionObject
  {
      V4_OBJECT2(IndexedBuiltinFunction, FunctionObject)
  };
  
  void Heap::IndexedBuiltinFunction::init(QV4::ExecutionContext *scope, uint index, VTable::Call call)
  {
      Heap::FunctionObject::init(scope);
      this->jsCall = call;
      this->index = index;
  }
  
  struct ArrowFunction : FunctionObject {
      V4_OBJECT2(ArrowFunction, FunctionObject)
      V4_INTERNALCLASS(ArrowFunction)
      enum { NInlineProperties = 3 };
  
      static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
  };
  
  struct ScriptFunction : ArrowFunction {
      V4_OBJECT2(ScriptFunction, ArrowFunction)
      V4_INTERNALCLASS(ScriptFunction)
  
      static ReturnedValue virtualCallAsConstructor(const FunctionObject *, const Value *argv, int argc, const Value *);
  
      Heap::InternalClass *classForConstructor() const;
  };
  
  struct MemberFunction : ArrowFunction {
      V4_OBJECT2(MemberFunction, ArrowFunction)
      V4_INTERNALCLASS(MemberFunction)
  };
  
  struct ConstructorFunction : ScriptFunction {
      V4_OBJECT2(ConstructorFunction, ScriptFunction)
      V4_INTERNALCLASS(ConstructorFunction)
      static ReturnedValue virtualCallAsConstructor(const FunctionObject *, const Value *argv, int argc, const Value *);
      static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
  };
  
  struct DefaultClassConstructorFunction : FunctionObject {
      V4_OBJECT2(DefaultClassConstructorFunction, FunctionObject)
      static ReturnedValue virtualCallAsConstructor(const FunctionObject *, const Value *argv, int argc, const Value *);
      static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
  };
  
  struct BoundFunction: FunctionObject {
      V4_OBJECT2(BoundFunction, FunctionObject)
  
      static Heap::BoundFunction *create(ExecutionContext *scope, FunctionObject *target, const Value &boundThis, QV4::MemberData *boundArgs)
      {
          return scope->engine()->memoryManager->allocate<BoundFunction>(scope, target, boundThis, boundArgs);
      }
  
      Heap::FunctionObject *target() const { return d()->target; }
      Value boundThis() const { return d()->boundThis; }
      Heap::MemberData *boundArgs() const { return d()->boundArgs; }
  
      static ReturnedValue virtualCallAsConstructor(const FunctionObject *, const Value *argv, int argc, const Value *);
      static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
  };
  
  inline bool FunctionObject::isBoundFunction() const
  {
      return d()->vtable() == BoundFunction::staticVTable();
  }
  
  inline ReturnedValue checkedResult(QV4::ExecutionEngine *v4, ReturnedValue result)
  {
      return v4->hasException ? QV4::Encode::undefined() : result;
  }
  
  }
  
  QT_END_NAMESPACE
  
  #endif // QMLJS_OBJECTS_H
  