/*

 *  Copyright (C) 1999-2000 Harri Porten (porten@kde.org)

 *  Copyright (C) 2002, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.

 *

 *  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; see the file COPYING.LIB.  If not, write to

 *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,

 *  Boston, MA 02110-1301, USA.

 *

 */

#ifndef Operations_h

#define Operations_h

#include "ExceptionHelpers.h"

#include "Interpreter.h"

#include "JSImmediate.h"

#include "JSNumberCell.h"

#include "JSString.h"

namespace JSC {

    NEVER_INLINE JSValue jsAddSlowCase(CallFrame*, JSValue, JSValue);

    JSValue jsTypeStringForValue(CallFrame*, JSValue);

    bool jsIsObjectType(JSValue);

    bool jsIsFunctionType(JSValue);

    ALWAYS_INLINE JSValue jsString(ExecState* exec, JSString* s1, JSString* s2)

    {

        unsigned length1 = s1->length();

        if (!length1)

            return s2;

        unsigned length2 = s2->length();

        if (!length2)

            return s1;

        if ((length1 + length2) < length1)

            return throwOutOfMemoryError(exec);

        unsigned fiberCount = s1->size() + s2->size();

        JSGlobalData* globalData = &exec->globalData();

        if (fiberCount <= JSString::s_maxInternalRopeLength)

            return new (globalData) JSString(globalData, fiberCount, s1, s2);

        JSString::RopeBuilder ropeBuilder(fiberCount);

        if (UNLIKELY(ropeBuilder.isOutOfMemory()))

            return throwOutOfMemoryError(exec);

        ropeBuilder.append(s1);

        ropeBuilder.append(s2);

        return new (globalData) JSString(globalData, ropeBuilder.release());

    }

    ALWAYS_INLINE JSValue jsString(ExecState* exec, const UString& u1, JSString* s2)

    {

        unsigned length1 = u1.size();

        if (!length1)

            return s2;

        unsigned length2 = s2->length();

        if (!length2)

            return jsString(exec, u1);

        if ((length1 + length2) < length1)

            return throwOutOfMemoryError(exec);

        unsigned fiberCount = 1 + s2->size();

        JSGlobalData* globalData = &exec->globalData();

        if (fiberCount <= JSString::s_maxInternalRopeLength)

            return new (globalData) JSString(globalData, fiberCount, u1, s2);

        JSString::RopeBuilder ropeBuilder(fiberCount);

        if (UNLIKELY(ropeBuilder.isOutOfMemory()))

            return throwOutOfMemoryError(exec);

        ropeBuilder.append(u1);

        ropeBuilder.append(s2);

        return new (globalData) JSString(globalData, ropeBuilder.release());

    }

    ALWAYS_INLINE JSValue jsString(ExecState* exec, JSString* s1, const UString& u2)

    {

        unsigned length1 = s1->length();

        if (!length1)

            return jsString(exec, u2);

        unsigned length2 = u2.size();

        if (!length2)

            return s1;

        if ((length1 + length2) < length1)

            return throwOutOfMemoryError(exec);

        unsigned fiberCount = s1->size() + 1;

        JSGlobalData* globalData = &exec->globalData();

        if (fiberCount <= JSString::s_maxInternalRopeLength)

            return new (globalData) JSString(globalData, fiberCount, s1, u2);

        JSString::RopeBuilder ropeBuilder(fiberCount);

        if (UNLIKELY(ropeBuilder.isOutOfMemory()))

            return throwOutOfMemoryError(exec);

        ropeBuilder.append(s1);

        ropeBuilder.append(u2);

        return new (globalData) JSString(globalData, ropeBuilder.release());

    }

    ALWAYS_INLINE JSValue jsString(ExecState* exec, const UString& u1, const UString& u2)

    {

        unsigned length1 = u1.size();

        if (!length1)

            return jsString(exec, u2);

        unsigned length2 = u2.size();

        if (!length2)

            return jsString(exec, u1);

        if ((length1 + length2) < length1)

            return throwOutOfMemoryError(exec);

        JSGlobalData* globalData = &exec->globalData();

        return new (globalData) JSString(globalData, u1, u2);

    }

    ALWAYS_INLINE JSValue jsString(ExecState* exec, const UString& u1, const UString& u2, const UString& u3)

    {

        unsigned length1 = u1.size();

        unsigned length2 = u2.size();

        unsigned length3 = u3.size();

        if (!length1)

            return jsString(exec, u2, u3);

        if (!length2)

            return jsString(exec, u1, u3);

        if (!length3)

            return jsString(exec, u1, u2);

        if ((length1 + length2) < length1)

            return throwOutOfMemoryError(exec);

        if ((length1 + length2 + length3) < length3)

            return throwOutOfMemoryError(exec);

        JSGlobalData* globalData = &exec->globalData();

        return new (globalData) JSString(globalData, u1, u2, u3);

    }

    ALWAYS_INLINE JSValue jsString(ExecState* exec, Register* strings, unsigned count)

    {

        ASSERT(count >= 3);

        unsigned fiberCount = 0;

        for (unsigned i = 0; i < count; ++i) {

            JSValue v = strings[i].jsValue();

            if (LIKELY(v.isString()))

                fiberCount += asString(v)->size();

            else

                ++fiberCount;

        }

        JSGlobalData* globalData = &exec->globalData();

        if (fiberCount == 3)

            return new (globalData) JSString(exec, strings[0].jsValue(), strings[1].jsValue(), strings[2].jsValue());

        JSString::RopeBuilder ropeBuilder(fiberCount);

        if (UNLIKELY(ropeBuilder.isOutOfMemory()))

            return throwOutOfMemoryError(exec);

        unsigned length = 0;

        bool overflow = false;

        for (unsigned i = 0; i < count; ++i) {

            JSValue v = strings[i].jsValue();

            if (LIKELY(v.isString()))

                ropeBuilder.append(asString(v));

            else

                ropeBuilder.append(v.toString(exec));

            unsigned newLength = ropeBuilder.length();

            if (newLength < length)

                overflow = true;

            length = newLength;

        }

        if (overflow)

            return throwOutOfMemoryError(exec);

        return new (globalData) JSString(globalData, ropeBuilder.release());

    }

    ALWAYS_INLINE JSValue jsString(ExecState* exec, JSValue thisValue)

    {

        unsigned fiberCount = 0;

        if (LIKELY(thisValue.isString()))

            fiberCount += asString(thisValue)->size();

        else

            ++fiberCount;

        for (unsigned i = 0; i < exec->argumentCount(); ++i) {

            JSValue v = exec->argument(i);

            if (LIKELY(v.isString()))

                fiberCount += asString(v)->size();

            else

                ++fiberCount;

        }

        JSString::RopeBuilder ropeBuilder(fiberCount);

        if (UNLIKELY(ropeBuilder.isOutOfMemory()))

            return throwOutOfMemoryError(exec);

        if (LIKELY(thisValue.isString()))

            ropeBuilder.append(asString(thisValue));

        else

            ropeBuilder.append(thisValue.toString(exec));

        unsigned length = 0;

        bool overflow = false;

        for (unsigned i = 0; i < exec->argumentCount(); ++i) {

            JSValue v = exec->argument(i);

            if (LIKELY(v.isString()))

                ropeBuilder.append(asString(v));

            else

                ropeBuilder.append(v.toString(exec));

            unsigned newLength = ropeBuilder.length();

            if (newLength < length)

                overflow = true;

            length = newLength;

        }

        if (overflow)

            return throwOutOfMemoryError(exec);

        JSGlobalData* globalData = &exec->globalData();

        return new (globalData) JSString(globalData, ropeBuilder.release());

    }

    // ECMA 11.9.3

    inline bool JSValue::equal(ExecState* exec, JSValue v1, JSValue v2)

    {

        if (v1.isInt32() && v2.isInt32())

            return v1 == v2;

        return equalSlowCase(exec, v1, v2);

    }

    ALWAYS_INLINE bool JSValue::equalSlowCaseInline(ExecState* exec, JSValue v1, JSValue v2)

    {

        do {

            if (v1.isNumber() && v2.isNumber())

                return v1.uncheckedGetNumber() == v2.uncheckedGetNumber();

            bool s1 = v1.isString();

            bool s2 = v2.isString();

            if (s1 && s2)

                return asString(v1)->value(exec) == asString(v2)->value(exec);

            if (v1.isUndefinedOrNull()) {

                if (v2.isUndefinedOrNull())

                    return true;

                if (!v2.isCell())

                    return false;

                return v2.asCell()->structure()->typeInfo().masqueradesAsUndefined();

            }

            if (v2.isUndefinedOrNull()) {

                if (!v1.isCell())

                    return false;

                return v1.asCell()->structure()->typeInfo().masqueradesAsUndefined();

            }

            if (v1.isObject()) {

                if (v2.isObject())

                    return v1 == v2;

                JSValue p1 = v1.toPrimitive(exec);

                if (exec->hadException())

                    return false;

                v1 = p1;

                if (v1.isInt32() && v2.isInt32())

                    return v1 == v2;

                continue;

            }

            if (v2.isObject()) {

                JSValue p2 = v2.toPrimitive(exec);

                if (exec->hadException())

                    return false;

                v2 = p2;

                if (v1.isInt32() && v2.isInt32())

                    return v1 == v2;

                continue;

            }

            if (s1 || s2) {

                double d1 = v1.toNumber(exec);

                double d2 = v2.toNumber(exec);

                return d1 == d2;

            }

            if (v1.isBoolean()) {

                if (v2.isNumber())

                    return static_cast<double>(v1.getBoolean()) == v2.uncheckedGetNumber();

            } else if (v2.isBoolean()) {

                if (v1.isNumber())

                    return v1.uncheckedGetNumber() == static_cast<double>(v2.getBoolean());

            }

            return v1 == v2;

        } while (true);

    }

    // ECMA 11.9.3

    ALWAYS_INLINE bool JSValue::strictEqualSlowCaseInline(ExecState* exec, JSValue v1, JSValue v2)

    {

        ASSERT(v1.isCell() && v2.isCell());

        if (v1.asCell()->isString() && v2.asCell()->isString())

            return asString(v1)->value(exec) == asString(v2)->value(exec);

        return v1 == v2;

    }

    inline bool JSValue::strictEqual(ExecState* exec, JSValue v1, JSValue v2)

    {

        if (v1.isInt32() && v2.isInt32())

            return v1 == v2;

        if (v1.isNumber() && v2.isNumber())

            return v1.uncheckedGetNumber() == v2.uncheckedGetNumber();

        if (!v1.isCell() || !v2.isCell())

            return v1 == v2;

        return strictEqualSlowCaseInline(exec, v1, v2);

    }

    ALWAYS_INLINE bool jsLess(CallFrame* callFrame, JSValue v1, JSValue v2)

    {

        if (v1.isInt32() && v2.isInt32())

            return v1.asInt32() < v2.asInt32();

        double n1;

        double n2;

        if (v1.getNumber(n1) && v2.getNumber(n2))

            return n1 < n2;

        JSGlobalData* globalData = &callFrame->globalData();

        if (isJSString(globalData, v1) && isJSString(globalData, v2))

            return asString(v1)->value(callFrame) < asString(v2)->value(callFrame);

        JSValue p1;

        JSValue p2;

        bool wasNotString1 = v1.getPrimitiveNumber(callFrame, n1, p1);

        bool wasNotString2 = v2.getPrimitiveNumber(callFrame, n2, p2);

        if (wasNotString1 | wasNotString2)

            return n1 < n2;

        return asString(p1)->value(callFrame) < asString(p2)->value(callFrame);

    }

    inline bool jsLessEq(CallFrame* callFrame, JSValue v1, JSValue v2)

    {

        if (v1.isInt32() && v2.isInt32())

            return v1.asInt32() <= v2.asInt32();

        double n1;

        double n2;

        if (v1.getNumber(n1) && v2.getNumber(n2))

            return n1 <= n2;

        JSGlobalData* globalData = &callFrame->globalData();

        if (isJSString(globalData, v1) && isJSString(globalData, v2))

            return !(asString(v2)->value(callFrame) < asString(v1)->value(callFrame));

        JSValue p1;

        JSValue p2;

        bool wasNotString1 = v1.getPrimitiveNumber(callFrame, n1, p1);

        bool wasNotString2 = v2.getPrimitiveNumber(callFrame, n2, p2);

        if (wasNotString1 | wasNotString2)

            return n1 <= n2;

        return !(asString(p2)->value(callFrame) < asString(p1)->value(callFrame));

    }

    // Fast-path choices here are based on frequency data from SunSpider:

    //    <times> Add case: <t1> <t2>

    //    ---------------------------

    //    5626160 Add case: 3 3 (of these, 3637690 are for immediate values)

    //    247412  Add case: 5 5

    //    20900   Add case: 5 6

    //    13962   Add case: 5 3

    //    4000    Add case: 3 5

    ALWAYS_INLINE JSValue jsAdd(CallFrame* callFrame, JSValue v1, JSValue v2)

    {

        double left = 0.0, right;

        if (v1.getNumber(left) && v2.getNumber(right))

            return jsNumber(callFrame, left + right);

        if (v1.isString()) {

            return v2.isString()

                ? jsString(callFrame, asString(v1), asString(v2))

                : jsString(callFrame, asString(v1), v2.toPrimitiveString(callFrame));

        }

        // All other cases are pretty uncommon

        return jsAddSlowCase(callFrame, v1, v2);

    }

    inline size_t normalizePrototypeChain(CallFrame* callFrame, JSValue base, JSValue slotBase, const Identifier& propertyName, size_t& slotOffset)

    {

        JSCell* cell = asCell(base);

        size_t count = 0;

        while (slotBase != cell) {

            JSValue v = cell->structure()->prototypeForLookup(callFrame);

            // If we didn't find slotBase in base's prototype chain, then base

            // must be a proxy for another object.

            if (v.isNull())

                return 0;

            cell = asCell(v);

            // Since we're accessing a prototype in a loop, it's a good bet that it

            // should not be treated as a dictionary.

            if (cell->structure()->isDictionary()) {

                asObject(cell)->flattenDictionaryObject();

                if (slotBase == cell)

                    slotOffset = cell->structure()->get(propertyName); 

            }

            ++count;

        }

        ASSERT(count);

        return count;

    }

    inline size_t normalizePrototypeChain(CallFrame* callFrame, JSCell* base)

    {

        size_t count = 0;

        while (1) {

            JSValue v = base->structure()->prototypeForLookup(callFrame);

            if (v.isNull())

                return count;

            base = asCell(v);

            // Since we're accessing a prototype in a loop, it's a good bet that it

            // should not be treated as a dictionary.

            if (base->structure()->isDictionary())

                asObject(base)->flattenDictionaryObject();

            ++count;

        }

    }

    ALWAYS_INLINE JSValue resolveBase(CallFrame* callFrame, Identifier& property, ScopeChainNode* scopeChain)

    {

        ScopeChainIterator iter = scopeChain->begin();

        ScopeChainIterator next = iter;

        ++next;

        ScopeChainIterator end = scopeChain->end();

        ASSERT(iter != end);

        PropertySlot slot;

        JSObject* base;

        while (true) {

            base = *iter;

            if (next == end || base->getPropertySlot(callFrame, property, slot))

                return base;

            iter = next;

            ++next;

        }

        ASSERT_NOT_REACHED();

        return JSValue();

    }

} // namespace JSC

#endif // Operations_h