qscriptcontext_p.cpp

奇趣公司比较新的qt/emd版本

/****************************************************************************
**
** Copyright (C) 1992-2007 Trolltech ASA. All rights reserved.
**
** This file is part of the QtScript module of the Qt Toolkit.
**
** This file may be used under the terms of the GNU General Public
** License version 2.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of
** this file.  Please review the following information to ensure GNU
** General Public Licensing requirements will be met:
** http://trolltech.com/products/qt/licenses/licensing/opensource/
**
** If you are unsure which license is appropriate for your use, please
** review the following information:
** http://trolltech.com/products/qt/licenses/licensing/licensingoverview
** or contact the sales department at [e-mail].
**
** In addition, as a special exception, Trolltech gives you certain
** additional rights. These rights are described in the Trolltech GPL
** Exception version 1.0, which can be found at
** http://www.trolltech.com/products/qt/gplexception/ and in the file
** GPL_EXCEPTION.txt in this package.
**
** In addition, as a special exception, Trolltech, as the sole copyright
** holder for Qt Designer, grants users of the Qt/Eclipse Integration
** plug-in the right for the Qt/Eclipse Integration to link to
** functionality provided by Qt Designer and its related libraries.
**
** Trolltech reserves all rights not expressly granted herein.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
****************************************************************************/

#include <QtCore/QtDebug>

#ifndef QT_NO_SCRIPT

#include "qscriptcontext_p.h"
#include "qscriptengine_p.h"
#include "qscriptvalueimpl_p.h"
#include "qscriptmember_p.h"
#include "qscriptobject_p.h"
#include "qscriptprettypretty_p.h"
#include "qscriptast_p.h"
#include "qscriptnodepool_p.h"
#include "qscriptcompiler_p.h"
#include "qscriptextenumeration_p.h"

#include <math.h> // floor & friends...

#define Q_SCRIPT_NO_PRINT_GENERATED_CODE

#define Q_SCRIPT_NO_JOINED_FUNCTION

#define CHECK_TEMPSTACK(needed) do { \
    if (stackPtr + needed >= eng->tempStackEnd) { \
        throwError(QLatin1String("out of memory")); \
        HandleException(); \
    } \
} while (0)

#ifndef Q_SCRIPT_NO_PRINT_GENERATED_CODE
static QTextStream qout(stderr, QIODevice::WriteOnly);
#endif

static inline void qscript_uint_to_string_helper(uint i, QString &s)
{
    switch (i) {
    case 0: case 1: case 2: case 3: case 4:
    case 5: case 6: case 7: case 8: case 9:
        s += QLatin1Char('0' + i);
        break;

    default:
        qscript_uint_to_string_helper(i / 10, s);
        s += QLatin1Char('0' + (i % 10));
    }
}

static inline void qscript_uint_to_string(qsreal i, QString &s)
{
    if (i < 0)
        return; // nothing to do

    qsreal x = ::fmod(i, 10);

    if (x != 0.0 && x != 1.0
            && x != 2.0 && x != 3.0
            && x != 4.0 && x != 5.0
            && x != 6.0 && x != 7.0
            && x != 8.0 && x != 9.0)
        return; // nothing to do

    qscript_uint_to_string_helper(uint(i), s);
}

static inline qint32 toArrayIndex(const QScriptValueImpl &v)
{
    if (v.isNumber()) {
        if (floor(v.m_number_value) == v.m_number_value)
            return v.toUInt32();
    } else if (v.isString()) {
        QByteArray bytes = v.m_string_value->s.toUtf8();
        char *eptr;
        quint32 pos = strtoul(bytes.constData(), &eptr, 10);
        if ((eptr == bytes.constData() + bytes.size())
            && (QByteArray::number(pos) == bytes)) {
            return pos;
        }
    }
    return -1;
}

#define CREATE_MEMBER(__obj__, __name__, __member__, __flags__) do { \
    (__obj__).createMember(__name__, __member__, __flags__); \
    eng->adjustBytesAllocated(sizeof(QScript::Member) + sizeof(QScriptValueImpl)); \
} while (0)

#define BEGIN_PREFIX_OPERATOR \
    QScriptValue::ResolveFlags mode; \
    mode = QScriptValue::ResolveFlags(stackPtr[0].m_int_value) \
    | QScriptValue::ResolvePrototype; \
    --stackPtr; \
    const QScriptValueImpl &object = stackPtr[-1]; \
    QScriptNameIdImpl *memberName = 0; \
    if (stackPtr[0].isString() && stackPtr[0].m_string_value->unique) \
        memberName = stackPtr[0].m_string_value; \
    else \
        memberName = eng->nameId(stackPtr[0].toString(), /*persistent=*/false); \
    QScript::Member member; \
    QScriptValueImpl base; \
    QScriptValueImpl value; \
    QScriptValueImpl getter; \
    QScriptValueImpl setter; \
    const bool isMemberAssignment = (object.m_object_value != m_scopeChain.m_object_value); \
    if (object.resolve(memberName, &member, &base, mode)) { \
        base.get(member, &value); \
        if (hasUncaughtException()) { \
            stackPtr -= 2; \
            HandleException(); \
        } else if (member.isGetterOrSetter()) { \
            if (member.isGetter()) { \
                getter = value; \
                if (!member.isSetter() && !base.m_object_value->findSetter(&member)) { \
                    stackPtr -= 2; \
                    throwError(QLatin1String("No setter defined")); \
                    HandleException(); \
                } \
                base.get(member, &setter); \
            } else { \
                setter = value; \
                QScript::Member tmp = member; \
                if (!base.m_object_value->findGetter(&member)) { \
                    stackPtr -= 2; \
                    throwError(QLatin1String("No getter defined")); \
                    HandleException(); \
                } \
                base.get(member, &getter); \
                member = tmp; \
            } \
            value = getter.call(object); \
            if (hasUncaughtException()) { \
                stackPtr -= 2; \
                Done(); \
            } \
        } \
    } else if (!isMemberAssignment) { \
        stackPtr -= 2; \
        throwNotDefined(memberName); \
        HandleException(); \
    } else { \
        base = object; \
        CREATE_MEMBER(base, memberName, &member, /*flags=*/0); \
        eng->newUndefined(&value); \
    }

#define END_PREFIX_OPERATOR \
    if (member.isSetter()) { \
        setter.call(object, QScriptValueImplList() << value); \
        if (hasUncaughtException()) { \
            stackPtr -= 2; \
            Done(); \
        } \
    } else { \
        if (isMemberAssignment && (base.m_object_value != object.m_object_value)) { \
            base = object; \
            CREATE_MEMBER(base, memberName, &member, /*flags=*/0); \
        } \
        if (member.isWritable()) { \
            base.put(member, value); \
            if (hasUncaughtException()) { \
                stackPtr -= 2; \
                HandleException(); \
            } \
        } \
    } \
    *--stackPtr = value; \
    ++iPtr;

#define BEGIN_INPLACE_OPERATOR \
    if (! stackPtr[-1].isReference()) { \
        stackPtr -= 2; \
        throwSyntaxError(QLatin1String("invalid assignment lvalue")); \
        HandleException(); \
    } \
    QScriptValue::ResolveFlags mode; \
    mode = QScriptValue::ResolveFlags(stackPtr[-1].m_int_value) \
           | QScriptValue::ResolvePrototype; \
    QScriptValueImpl object = eng->toObject(stackPtr[-3]); \
    if (! object.isValid()) { \
        stackPtr -= 4; \
        throwTypeError(QLatin1String("not an object")); \
        HandleException(); \
    } \
    QScriptNameIdImpl *memberName = 0; \
    if (stackPtr[-2].isString() && stackPtr[-2].m_string_value->unique) \
        memberName = stackPtr[-2].m_string_value; \
    else \
        memberName = eng->nameId(stackPtr[-2].toString(), /*persistent=*/false); \
    QScriptValueImpl lhs; \
    QScriptValueImpl base; \
    QScript::Member member; \
    QScriptValueImpl getter; \
    QScriptValueImpl setter; \
    const bool isMemberAssignment = (object.m_object_value != m_scopeChain.m_object_value); \
    if (object.resolve(memberName, &member, &base, mode)) { \
        base.get(member, &lhs); \
        if (hasUncaughtException()) { \
            stackPtr -= 4; \
            HandleException(); \
        } else if (member.isGetterOrSetter()) { \
            if (member.isGetter()) { \
                getter = lhs; \
                if (!member.isSetter() && !base.m_object_value->findSetter(&member)) { \
                    stackPtr -= 4; \
                    throwError(QLatin1String("No setter defined")); \
                    HandleException(); \
                } \
                base.get(member, &setter); \
            } else { \
                setter = lhs; \
                QScript::Member tmp = member; \
                if (!base.m_object_value->findGetter(&member)) { \
                    stackPtr -= 4; \
                    throwError(QLatin1String("No getter defined")); \
                    HandleException(); \
                } \
                base.get(member, &getter); \
                member = tmp; \
            } \
            lhs = getter.call(object); \
            if (hasUncaughtException()) { \
                stackPtr -= 4; \
                Done(); \
            } \
        } \
    } else if (!isMemberAssignment) { \
        stackPtr -= 4; \
        throwNotDefined(memberName); \
        HandleException(); \
    } else { \
        base = object; \
        CREATE_MEMBER(base, memberName, &member, /*flags=*/0); \
        eng->newUndefined(&lhs); \
    } \
    const QScriptValueImpl &rhs = stackPtr[0];

#define END_INPLACE_OPERATOR \
    if (member.isSetter()) { \
        setter.call(object, QScriptValueImplList() << *stackPtr); \
        if (hasUncaughtException()) { \
            stackPtr -= 1; \
            Done(); \
        } \
    } else { \
        if (isMemberAssignment && (base.m_object_value != object.m_object_value)) { \
            base = object; \
            CREATE_MEMBER(base, memberName, &member, /*flags=*/0); \
        } \
        if (member.isWritable()) { \
            base.put(member, *stackPtr); \
            if (hasUncaughtException()) { \
                stackPtr -= 1; \
                HandleException(); \
            } \
        } \
    } \
    ++iPtr;

namespace QScript {

void ScriptFunction::execute(QScriptContextPrivate *context)
{
    if (! m_compiledCode) {
        QScriptEngine *eng = context->engine();
        Compiler compiler(eng);

        CompilationUnit unit = compiler.compile(m_definition->body, formals);
        if (! unit.isValid()) {
            context->throwError(unit.errorMessage());
            return;
        }

        m_compiledCode = m_astPool->createCompiledCode(m_definition->body, unit);
    }

    context->execute(m_compiledCode);
}

QString ScriptFunction::toString(QScriptContextPrivate *context) const
{
    QScriptEngine *eng = context->engine();
    QString str;
    QTextStream out(&str, QIODevice::WriteOnly);
    PrettyPretty pp(eng, out);
    pp(m_definition, /*indent=*/ 1);
    return str;
}

QString ScriptFunction::fileName() const
{
    return m_astPool->fileName();
}

QString ScriptFunction::functionName() const
{
    if (!m_definition->name)
        return QLatin1String("<anonymous>");
    return m_definition->name->s;
}

} // namespace QScript

/*!
  \internal

  Resolves and gets the value specified by \a stackPtr.
  stackPtr[0] contains the member specifier, stackPtr[-1] contains the object.
  If the member can be resolved, sets \a value to the value of that member,
  otherwise returns false.
*/
bool QScriptContextPrivate::resolveField(QScriptEnginePrivate *eng,
                                         QScriptValueImpl *stackPtr,
                                         QScriptValueImpl *value)
{
    const QScriptValueImpl &m = stackPtr[0];
    QScriptValueImpl &object = stackPtr[-1];

    if (! object.isObject())
        object = eng->toObject(object);

    if (! object.isValid())
        return false;

    if (QScript::Ecma::Array::Instance *arrayInstance = eng->arrayConstructor->get(object)) {
        qint32 pos = toArrayIndex(m);
        if (pos != -1) {
            *value = arrayInstance->value.at(pos);

            if (! value->isValid())
                eng->newUndefined(value);

            return true;
        }
    }

    QScriptNameIdImpl *nameId = m.isString() ? m.m_string_value : 0;

    if (! nameId || ! nameId->unique)
        nameId = eng->nameId(eng->convertToNativeString(m), /*persistent=*/false); // ### slow!

    QScript::Member member;
    QScriptValueImpl base;

    if (! object.resolve(nameId, &member, &base, QScriptValue::ResolveFull)) // ### ...
        return false;

    if (base.m_class == eng->m_globalObject.m_class)
        stackPtr[-1] = base;
    else if (object.m_class == eng->m_class_with)
        stackPtr[-1] = object.prototype();

    base.get(member, value);

    return true;
}

void QScriptContextPrivate::execute(QScript::Code *code)
{
    QScript::Code *oldCode = m_code;
    m_code = code;

#ifndef Q_SCRIPT_NO_PRINT_GENERATED_CODE
    qout << QLatin1String("function:") << endl;
    for (QScriptInstruction *current = code->firstInstruction; current != code->lastInstruction; ++current) {
        qout << int(current - code->firstInstruction) << QLatin1String(":\t");
        current->print(qout);
        qout << endl;
    }
    qout << endl;
#endif

    QScriptEnginePrivate *eng = QScriptEnginePrivate::get(engine());

    if (!parentContext())
        eng->setupProcessEvents();

    // set up the temp stack
    if (! tempStack)
        stackPtr = tempStack = eng->tempStackBegin;

    QScriptValueImpl undefined;
    eng->newUndefined(&undefined);

    catching = false;
    m_state = QScriptContext::NormalState;
    m_result = undefined;
    firstInstruction = code->firstInstruction;
    lastInstruction = code->lastInstruction;
    iPtr = code->firstInstruction; // ### kill iPtr

    m_scopeChain = m_activation;


#ifndef Q_SCRIPT_DIRECT_CODE

#  define I(opc) case QScriptInstruction::OP_##opc
#  define Next() goto Lfetch
#  define Done() goto Ldone
#  define HandleException() goto Lhandle_exception

Lfetch:


#else