kjs_binding.h

/*
 *  This file is part of the KDE libraries
 *  Copyright (C) 1999-2001 Harri Porten ([email protected])
 *  Copyright (C) 2003 Apple Computer, Inc.
 *  Copyright (C) 2007, 2008 Maksim Orlovich ([email protected])
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Library General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Library General Public License for more details.
 *
 *  You should have received a copy of the GNU Library General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

#ifndef _KJS_BINDING_H_
#define _KJS_BINDING_H_

#include <khtml_export.h>
#include <kjs/interpreter.h>
#include <kjs/global.h>
#include <wtf/HashMap.h>

#include <dom/dom_node.h>
#include <QVariant>
#include <QHash>
#include <QString>
#include <kjs/lookup.h>
#include <kjs/function.h>
#include <kjs/JSVariableObject.h>
#include <kjs/object_object.h>
#include <misc/shared.h>

#include <stdlib.h> // for abort

#define KJS_CHECK_THIS( ClassName, theObj ) \
    if (!theObj || !theObj->inherits(&ClassName::info)) { \
        KJS::UString errMsg = "Attempt at calling a function that expects a "; \
        errMsg += ClassName::info.className; \
        errMsg += " on a "; \
        errMsg += theObj->className(); \
        KJS::JSObject *err = KJS::Error::create(exec, KJS::TypeError, errMsg.ascii()); \
        exec->setException(err); \
        return err; \
    }

namespace KParts
{
class ReadOnlyPart;
class LiveConnectExtension;
}

namespace khtml
{
class ChildFrame;
}

namespace KJS
{

// For the ecma debugger we provide our own conversion rather than the
// use the native one, since using the toString
// method on object can invoke code
QString valueToString(KJS::JSValue *value);

// Serializes an exception for human consumption.
QString exceptionToString(ExecState *exec, JSValue *exception);

/**
 * Base class for all objects in this binding. Doesn't manage exceptions any more
 */
class DOMObject : public JSObject
{
protected:
    DOMObject() : JSObject() {}
    DOMObject(JSObject *proto) : JSObject(proto) {}
public:
    bool shouldMark() const
    {
        return !_prop.isEmpty();
    }
    UString toString(ExecState *exec) const override;
};

/**
 * We inherit from Interpreter, to save a pointer to the HTML part
 * that the interpreter runs for.
 * The interpreter also stores the DOM object - >KJS::DOMObject cache.
 */
class ScriptInterpreter : public Interpreter
{
public:
    ScriptInterpreter(JSGlobalObject *global, khtml::ChildFrame *frame);
    virtual ~ScriptInterpreter();

    // We need to keep track of wrappers in 2 ways:
    //  - we want the same wrapper for the same node (see #145775)
    //  - we want to drop all the references from this interpreter on clear, so
    //  wrappers don't stick around. Hence we have a global set and a per-interpreter one.

    // Reuses an existing wrapper, perhaps also updating the current map
    // to refer to it as well.
    DOMObject *getDOMObject(void *objectHandle)
    {
        DOMObject *existing = allDomObjects()->get(objectHandle);
        if (existing) {
            m_domObjects.set(objectHandle, existing);
        }
        return existing;
    }

    void putDOMObject(void *objectHandle, DOMObject *obj)
    {
        allDomObjects()->set(objectHandle, obj);
        m_domObjects.set(objectHandle, obj);
    }

    static void forgetDOMObject(void *objectHandle);

    void clear()
    {
        m_domObjects.clear(); // Global set will be cleared at GC time.
    }

    /**
     * Mark objects in the DOMObject cache.
     */
    void mark(bool isMain) override;
    KParts::ReadOnlyPart *part() const;

    int rtti() override
    {
        return 1;
    }

    /**
     * Set the event that is triggering the execution of a script, if any
     */
    void setCurrentEvent(DOM::Event *evt)
    {
        m_evt = evt;
    }
    void setInlineCode(bool inlineCode)
    {
        m_inlineCode = inlineCode;
    }
    void setProcessingTimerCallback(bool timerCallback)
    {
        m_timerCallback = timerCallback;
    }
    /**
     * "Smart" window.open policy
     */
    bool isWindowOpenAllowed() const;

    /**
     * CPU guard API. This should be used instead of Interpreter
     * methods as it manages the timeouts, including VG support
     */
    bool shouldInterruptScript() const override;
    void startCPUGuard();
    void stopCPUGuard();

    static void turnOffCPUGuard()
    {
        s_disableCPUGuard = true;
    }
private:
    khtml::ChildFrame *m_frame;
    HashMap<void *, DOMObject *> m_domObjects;
    static HashMap<void *, DOMObject *> *s_allDomObjects;
    static HashMap<void *, DOMObject *> *allDomObjects()
    {
        if (!s_allDomObjects) {
            s_allDomObjects = new HashMap<void *, DOMObject *>();
        }
        return s_allDomObjects;
    }

    DOM::Event *m_evt;
    bool m_inlineCode;
    bool m_timerCallback;
    static bool s_disableCPUGuard;
};

/** Some templates to help make wrappers. example:
    class Foo: public DOMWrapperObject<DOM::FooImpl> {
    }

    ...

    getWrapper<Foo>(exec, someImpl);
*/
template<typename Wrapper>
JSValue *getWrapper(ExecState *exec, typename Wrapper::wrappedType *g)
{
    DOMObject *ret = nullptr;
    if (!g) {
        return jsNull();
    }

    ScriptInterpreter *interp = static_cast<ScriptInterpreter *>(exec->dynamicInterpreter());
    if ((ret = interp->getDOMObject(g))) {
        return ret;
    }

    ret = new Wrapper(exec, g);
    interp->putDOMObject(g, ret);
    return ret;
}

template<typename Wrapped>
class DOMWrapperObject : public DOMObject
{
public:
    typedef Wrapped wrappedType;
    typedef DOMWrapperObject<Wrapped> WrapperBase;

    DOMWrapperObject(JSObject *proto, Wrapped *wrapee):
        DOMObject(proto), m_impl(wrapee)
    {}

    virtual ~DOMWrapperObject()
    {
        ScriptInterpreter::forgetDOMObject(m_impl.get());
    }

    bool toBoolean(ExecState *) const override
    {
        return true;
    }

    Wrapped *impl()
    {
        return m_impl.get();
    }
    const Wrapped *impl() const
    {
        return m_impl.get();
    }
private:
    SharedPtr<Wrapped> m_impl;
};

/**
 A little helper for setting stuff up given an entry
*/
template<class FuncImp, class ThisImp>
inline void getSlotFromEntry(const HashEntry *entry, ThisImp *thisObj, PropertySlot &slot)
{
    if (entry->attr & Function) {
        slot.setStaticEntry(thisObj, entry, staticFunctionGetter<FuncImp>);
    } else {
        slot.setStaticEntry(thisObj, entry, staticValueGetter<ThisImp>);
    }
}

/**
  Like getStaticPropertySlot but doesn't check the parent. Handy when there
  are both functions and values
 */
template <class FuncImp, class ThisImp>
inline bool getStaticOwnPropertySlot(const HashTable *table,
                                     ThisImp *thisObj, const Identifier &propertyName, PropertySlot &slot)
{
    const HashEntry *entry = Lookup::findEntry(table, propertyName);

    if (!entry) { // not found, forward to parent
        return false;
    }

    if (entry->attr & Function) {
        slot.setStaticEntry(thisObj, entry, staticFunctionGetter<FuncImp>);
    } else {
        slot.setStaticEntry(thisObj, entry, staticValueGetter<ThisImp>);
    }

    return true;
}

/**
  Handler for local table-looked up things.
*/
template<class ThisImp>
inline bool getStaticOwnValueSlot(const HashTable *table,
                                  ThisImp *thisObj, const Identifier &propertyName, PropertySlot &slot)
{
    const HashEntry *entry = Lookup::findEntry(table, propertyName);
    if (!entry) {
        return false;
    }

    assert(!(entry->attr & Function));
    slot.setStaticEntry(thisObj, entry, staticValueGetter<ThisImp>);
    return true;
}

/* Helper for the below*/
template<class JSTypeImp>
JSValue *indexGetterAdapter(ExecState *exec, JSObject *, unsigned, const PropertySlot &slot)
{
    JSTypeImp *thisObj = static_cast<JSTypeImp *>(slot.slotBase());
    return thisObj->indexGetter(exec, slot.index());
}

/**
 Handler for index properties. Will call "length" method on the listObj
 to determine whether it's in range, and arrange to have indexGetter called
*/
template<class ThisImp, class BaseObj>
inline bool getIndexSlot(ThisImp *thisObj, const BaseObj &listObj,
                         const Identifier &propertyName, PropertySlot &slot)
{
    bool ok;
    unsigned u = propertyName.toArrayIndex(&ok);
    if (ok && u < listObj.length()) {
        slot.setCustomIndex(thisObj, u, indexGetterAdapter<ThisImp>);
        return true;
    }
    return false;
}

/**
 Version that takes an external bound
*/
template<class ThisImp>
inline bool getIndexSlot(ThisImp *thisObj, unsigned lengthLimit,
                         const Identifier &propertyName, PropertySlot &slot)
{
    bool ok;
    unsigned u = propertyName.toArrayIndex(&ok);
    if (ok && u < lengthLimit) {
        slot.setCustomIndex(thisObj, u, indexGetterAdapter<ThisImp>);
        return true;
    }
    return false;
}

template<class ThisImp>
inline bool getIndexSlot(ThisImp *thisObj, int lengthLimit,
                         const Identifier &propertyName, PropertySlot &slot)
{
    return getIndexSlot(thisObj, (unsigned)lengthLimit, propertyName, slot);
}

/**
 Version w/o the bounds check
*/
template<class ThisImp>
inline bool getIndexSlot(ThisImp *thisObj, const Identifier &propertyName, PropertySlot &slot)
{
    bool ok;
    unsigned u = propertyName.toArrayIndex(&ok);
    if (ok) {
        slot.setCustomIndex(thisObj, u, indexGetterAdapter<ThisImp>);
        return true;
    }
    return false;
}

/* Helper for below */
JSValue *valueGetterAdapter(ExecState *exec, JSObject *, const Identifier &, const PropertySlot &slot);

/**
 This sets up the slot to return a particular JSValue*; unlike
 setValueSlot, it does not require there to be a location to point at
*/
inline bool getImmediateValueSlot(JSObject *thisObj, JSValue *value, PropertySlot &slot)
{
    slot.setCustomValue(thisObj, value, valueGetterAdapter);
    return true;
}

/**
 * Retrieve from cache, or create, a KJS object around a DOM object
 */
template<class DOMObj, class KJSDOMObj>
inline JSValue *cacheDOMObject(ExecState *exec, DOMObj *domObj)
{
    DOMObject *ret;
    if (!domObj) {
        return jsNull();
    }
    ScriptInterpreter *interp = static_cast<ScriptInterpreter *>(exec->dynamicInterpreter());
    if ((ret = interp->getDOMObject(domObj))) {
        return ret;
    } else {
        ret = new KJSDOMObj(exec, domObj);
        interp->putDOMObject(domObj, ret);
        return ret;
    }
}

/**
 * Convert an object to a Node. Returns 0 if not possible.
 */
DOM::NodeImpl *toNode(JSValue *);
/**
 *  Get a String object, or Null() if s is null
 */
JSValue *getStringOrNull(DOM::DOMString s);

/**
 * Null string if the value is null
 */
DOM::DOMString valueToStringWithNullCheck(ExecState *exec, JSValue *v);

/**
 * Convert a KJS value into a QVariant
 */
QVariant ValueToVariant(ExecState *exec, JSValue *val);

// Convert a DOM implementation exception code into a JavaScript exception in the execution state.
void setDOMException(ExecState *exec, int DOMExceptionCode);

// Helper class to call setDOMException on exit without adding lots of separate calls to that function.
class DOMExceptionTranslator
{
public:
    explicit DOMExceptionTranslator(ExecState *exec) : m_exec(exec), m_code(0) { }
    ~DOMExceptionTranslator()
    {
        setDOMException(m_exec, m_code);
    }
    operator int &()
    {
        return m_code;
    }
    operator int *()
    {
        return &m_code;
    }

    bool triggered()
    {
        return m_code;
    }
private:
    ExecState *m_exec;
    int m_code;
};

// convenience function
inline JSCell *jsString(const QString &s)
{
    return jsString(UString(s));
}

// This is used to create pseudo-constructor objects, like Mozillaish
// Element, HTMLDocument, etc., which do not act like real constructors,
// but do have the prototype property pointing to prototype of "instances"
#define DEFINE_PSEUDO_CONSTRUCTOR(ClassName) \
    class ClassName : public DOMObject { \
    public: \
        ClassName(ExecState *); \
        virtual const ClassInfo* classInfo() const { return &info; } \
        static const ClassInfo info; \
        static JSObject* self(ExecState *exec); \
        virtual bool implementsHasInstance() const; \
    };

#define IMPLEMENT_PSEUDO_CONSTRUCTOR_IMP(Class,ClassName,ProtoClass,ParentProto) \
    const ClassInfo Class::info = { ClassName, nullptr, nullptr, nullptr }; \
    Class::Class(ExecState* exec): DOMObject(ParentProto) {\
        /* Since ProtoClass ctor might need us, make sure we're registered */ \
        exec->lexicalInterpreter()->globalObject()->put(exec, "[[" ClassName ".constructor]]", this, KJS::Internal | KJS::DontEnum); \
        JSObject* proto = ProtoClass::self(exec); \
        putDirect(exec->propertyNames().prototype, proto, DontDelete|ReadOnly); \
    }\
    JSObject* Class::self(ExecState *exec) { \
        return cacheGlobalObject<Class>(exec, "[[" ClassName ".constructor]]"); \
    } \
    bool Class::implementsHasInstance() const { \
        return true; \
    }

#define IMPLEMENT_PSEUDO_CONSTRUCTOR(Class,ClassName,ProtoClass) \
    IMPLEMENT_PSEUDO_CONSTRUCTOR_IMP(Class,ClassName,ProtoClass,exec->lexicalInterpreter()->builtinObjectPrototype())

#define IMPLEMENT_PSEUDO_CONSTRUCTOR_WITH_PARENT(Class,ClassName,ProtoClass,ParentProtoClass) \
    IMPLEMENT_PSEUDO_CONSTRUCTOR_IMP(Class,ClassName,ProtoClass,ParentProtoClass::self(exec))

// This declares a constant table, which merely maps everything in its
// table to its token value. Can be used as a prototype
#define DEFINE_CONSTANT_TABLE(Class) \
    class Class : public DOMObject { \
    public: \
        Class(ExecState *exec): DOMObject(exec->lexicalInterpreter()->builtinObjectPrototype()) {} \
        \
        using KJS::JSObject::getOwnPropertySlot;\
        virtual bool getOwnPropertySlot(ExecState *exec, const Identifier& propertyName, PropertySlot& slot);\
        JSValue* getValueProperty(ExecState *exec, int token) const; \
        virtual const ClassInfo* classInfo() const { return &info; } \
        static const ClassInfo info; \
        static JSObject* self(ExecState *exec);\
        static Identifier* s_name; \
        static Identifier* name(); \
    };

// Emits an implementation of a constant table
#define IMPLEMENT_CONSTANT_TABLE(Class,ClassName) \
    bool Class::getOwnPropertySlot(ExecState *exec, const Identifier& propertyName, PropertySlot& slot) \
    { \
        return getStaticValueSlot<Class, DOMObject>(exec, &Class##Table, this, propertyName, slot);\
    }\
    JSValue* Class::getValueProperty(ExecState * /*exec*/, int token) const { \
        /* We use the token as the value to return directly*/ \
        return jsNumber((unsigned int)token); \
    }  \
    JSObject* Class::self(ExecState *exec) { \
        return cacheGlobalObject<Class>(exec,  *name()); \
    } \
    Identifier* Class::s_name = nullptr; \
    Identifier* Class::name() { \
        if (!s_name) s_name = new Identifier("[[" ClassName ".constant_table]]"); \
        return s_name; \
    } \
    const ClassInfo Class::info = { ClassName, nullptr, &Class##Table, nullptr };

// cacheGlobalObject<> is not in namespace KJS - need to use ::cacheGlobalObject<>
#define KJS_EMPTY_PROTOTYPE_IMP(ClassName, ClassProto, ProtoCode) \
    class ClassProto : public JSObject { \
        friend JSObject* KJS_CACHEGLOBALOBJECT_NS cacheGlobalObject<ClassProto>(ExecState *exec, const Identifier &propertyName); \
    public: \
        static JSObject* self(ExecState *exec) { \
            return KJS_CACHEGLOBALOBJECT_NS cacheGlobalObject<ClassProto>(exec, *name()); \
        } \
        virtual const ClassInfo *classInfo() const { return &info; } \
        static const ClassInfo info; \
    protected: \
        ClassProto( ExecState *exec ) \
            : JSObject( ProtoCode ) {} \
        \
        static Identifier* s_name; \
        static Identifier* name() { \
            if (!s_name) s_name = new Identifier("[[" ClassName ".prototype]]"); \
            return s_name; \
        }\
    }; \
    Identifier* ClassProto::s_name = nullptr; \
    const ClassInfo ClassProto::info = { ClassName, nullptr, nullptr, nullptr };

#define KJS_EMPTY_PROTOTYPE_WITH_PROTOTYPE(ClassName, ClassProto, ClassProtoProto) \
    KJS_EMPTY_PROTOTYPE_IMP(ClassName, ClassProto, ClassProtoProto::self(exec))

} // namespace

#endif