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Branched from the monolithic repo, Qt master branch, at commit
896db169ea224deb96c59ce8af800d019de63f12

1 files changed, 414 insertions, 0 deletions

diff --git a/src/xmlpatterns/expr/qexpression.cpp b/src/xmlpatterns/expr/qexpression.cpp
new file mode 100644
index 0000000..7a045e8
--- /dev/null
+++ b/src/xmlpatterns/expr/qexpression.cpp
@@ -0,0 +1,414 @@
+/****************************************************************************
+**
+** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtXmlPatterns module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qboolean_p.h"
+#include "qcommonvalues_p.h"
+#include "qemptysequence_p.h"
+#include "qliteral_p.h"
+#include "qliteralsequence_p.h"
+#include "qoperandsiterator_p.h"
+#include "qoptimizerframework_p.h"
+#include "qstaticfocuscontext_p.h"
+#include "qtypechecker_p.h"
+
+#include "qexpression_p.h"
+
+QT_BEGIN_NAMESPACE
+
+using namespace QPatternist;
+
+Expression::~Expression()
+{
+}
+
+StaticContext::Ptr Expression::finalizeStaticContext(const StaticContext::Ptr &context) const
+{
+    Q_ASSERT(context);
+    const ItemType::Ptr focusType(newFocusType());
+    Q_ASSERT(focusType);
+    return StaticContext::Ptr(new StaticFocusContext(focusType, context));
+}
+
+Expression::Ptr Expression::typeCheck(const StaticContext::Ptr &context,
+                                      const SequenceType::Ptr &reqType)
+{
+    Q_ASSERT(reqType);
+    typeCheckOperands(context);
+    return TypeChecker::applyFunctionConversion(Expression::Ptr(this), reqType, context);
+}
+
+void Expression::typeCheckOperands(const StaticContext::Ptr &context)
+{
+    const Expression::List ops(operands());
+
+    /* Check if this expression has any operands at all. */
+    if(ops.isEmpty())
+        return; /* We're done, early exit. */
+
+    const SequenceType::List opTypes(expectedOperandTypes());
+    Expression::List result;
+
+    /* If we create a focus, we handle the last one specially, so avoid it in the loop. */
+    const bool createsFocus = has(CreatesFocusForLast);
+    const SequenceType::List::const_iterator typeEnd(createsFocus ? --opTypes.constEnd()
+                                                                  : opTypes.constEnd());
+    const Expression::List::const_iterator end(createsFocus ? --ops.constEnd()
+                                                            : ops.constEnd());
+
+    SequenceType::List::const_iterator reqType(opTypes.constBegin());
+    SequenceType::Ptr t(*reqType);
+    // TODO we assign twice to t here(also below in loop) when ops.size() > 1
+
+    Expression::List::const_iterator it(ops.constBegin());
+
+    for(; it != end; ++it)
+    {
+        /* This ensures that the last expectedOperandType stays, and is
+         * used for all other operands. This is used for expressions that
+         * have an infinite amount of operands, such as the concat() function. */
+        if(reqType != typeEnd)
+        {
+            t = *reqType;
+            ++reqType;
+        }
+
+         /* Let the child & its children typecheck. */
+        result.append((*it)->typeCheck(context, t));
+    }
+
+    if(createsFocus)
+    {
+        const StaticContext::Ptr newContext(finalizeStaticContext(context));
+        result.append(ops.last()->typeCheck(newContext, opTypes.last()));
+    }
+
+    setOperands(result);
+}
+
+Expression::Ptr Expression::invokeOptimizers(const Expression::Ptr &expr,
+                                             const StaticContext::Ptr &context)
+{
+    Q_ASSERT(expr);
+
+    const OptimizationPass::List opts(expr->optimizationPasses());
+
+    if(opts.isEmpty()) /* Early exit. */
+    {
+        return expr;
+    }
+
+    const OptimizationPass::List::const_iterator passEnd(opts.constEnd());
+    const OptimizationPass::List::const_iterator end(opts.constEnd());
+    OptimizationPass::List::const_iterator passIt(opts.constBegin());
+
+    for(; passIt != passEnd; ++passIt) /* Invoke each optimization pass. */
+    {
+        const OptimizationPass::Ptr pass(*passIt); /* Alias, for readability. */
+        OptimizationPass::ExpressionMarker sourceMarker(pass->sourceExpression);
+
+        if(pass->startIdentifier && !pass->startIdentifier->matches(expr))
+        {
+            /* This pass specified a start identifier and it did
+             * not match -- let's try the next OptimizationPass. */
+            continue;
+        }
+
+        const ExpressionIdentifier::List::const_iterator idEnd(pass->operandIdentifiers.constEnd());
+        ExpressionIdentifier::List::const_iterator idIt(pass->operandIdentifiers.constBegin());
+        const Expression::List ops(expr->operands());
+        const Expression::List::const_iterator opEnd(ops.constEnd());
+        Expression::List::const_iterator opIt(ops.constBegin());
+
+        switch(pass->operandsMatchMethod)
+        {
+            case OptimizationPass::Sequential:
+            {
+                for(; opIt != opEnd; ++opIt)
+                {
+                    const Expression::Ptr operand(*opIt); /* Alias, for readability. */
+                    const ExpressionIdentifier::Ptr opIdentifier(*idIt); /* Alias, for readability. */
+                    if(opIdentifier && !opIdentifier->matches(operand))
+                    {
+                        break;
+                    }
+
+                    ++idIt;
+                }
+
+                if(opIt == opEnd)
+                    break; /* All operands matched, so this pass matched. */
+                else
+                {
+                    /* The loop above did not finish which means all operands did not match.
+                       Therefore, this OptimizationPass did not match -- let's try the next one. */
+                    continue;
+                }
+            }
+            case OptimizationPass::AnyOrder:
+            {
+                Q_ASSERT_X(ops.count() == 2, Q_FUNC_INFO,
+                           "AnyOrder is currently only supported for Expressions with two operands.");
+                if(pass->operandIdentifiers.first()->matches(ops.first()) &&
+                   pass->operandIdentifiers.last()->matches(ops.last()))
+                {
+                    break;
+                }
+                else if(pass->operandIdentifiers.first()->matches(ops.last()) &&
+                        pass->operandIdentifiers.last()->matches(ops.first()))
+                {
+                    sourceMarker.first() = 1;
+                    sourceMarker[1] = 0;
+                    break; /* This pass matched. */
+                }
+                else
+                    continue; /* This pass didn't match, let's loop through the next pass. */
+            }
+        }
+
+        /* Figure out the source Expression, if any. */
+        Expression::List operands;
+        Expression::Ptr sourceExpr;
+
+        if(!sourceMarker.isEmpty())
+        {
+            const OptimizationPass::ExpressionMarker::const_iterator mEnd(sourceMarker.constEnd());
+            OptimizationPass::ExpressionMarker::const_iterator mIt(sourceMarker.constBegin());
+            sourceExpr = expr;
+
+            for(; mIt != mEnd; ++mIt)
+            {
+                Q_ASSERT(*mIt >= 0);
+                sourceExpr = sourceExpr->operands().at(*mIt);
+            }
+
+            operands.append(sourceExpr);
+        }
+
+        if(operands.isEmpty())
+        {
+            Q_ASSERT(pass->resultCreator);
+            return pass->resultCreator->create(Expression::List(), context, expr.data())->compress(context);
+        }
+        else if(pass->resultCreator)
+            return pass->resultCreator->create(operands, context, expr.data())->compress(context);
+        else
+        {
+            return sourceExpr;
+        }
+    }
+
+    return expr;
+}
+
+Expression::Ptr Expression::compress(const StaticContext::Ptr &context)
+{
+    if(!compressOperands(context))
+    {
+        /* At least one of the operands cannot be evaluated at compile, so
+         * 'this' Expression cannot const fold. */
+        return invokeOptimizers(Expression::Ptr(this), context);
+    }
+
+    Expression::Ptr retval;
+
+    if(hasDependency(DisableElimination))
+        retval = Expression::Ptr(this);
+    else
+        retval = constantPropagate(context);
+
+    return invokeOptimizers(retval, context);
+}
+
+Expression::Ptr Expression::constantPropagate(const StaticContext::Ptr &context) const
+{
+    Q_ASSERT(context);
+
+    /* Optimization: We rewrite literals to literals here, which is pointless.
+     * Maybe we should have a property which says "doesn't disable elimination
+     * but don't eliminate me." */
+    if(staticType()->cardinality().allowsMany())
+    {
+        Item::Iterator::Ptr it(evaluateSequence(context->dynamicContext()));
+        Item::List result;
+        Item item(it->next());
+
+        while(item)
+        {
+            result.append(item);
+            item = it->next();
+        }
+
+        switch(result.count())
+        {
+            case 0:
+                return EmptySequence::create(this, context);
+            case 1:
+                return rewrite(Expression::Ptr(new Literal(result.first())), context);
+            default:
+                return rewrite(Expression::Ptr(new LiteralSequence(result)), context);
+        }
+    }
+    else
+    {
+        const Item item(evaluateSingleton(context->dynamicContext()));
+
+        if(item)
+            return rewrite(Expression::Ptr(new Literal(item)), context);
+        else
+            return EmptySequence::create(this, context);
+    }
+}
+
+Item::Iterator::Ptr Expression::evaluateSequence(const DynamicContext::Ptr &context) const
+{
+    const Item item(evaluateSingleton(context));
+
+    if(item)
+        return makeSingletonIterator(item);
+    else
+        return CommonValues::emptyIterator;
+}
+
+Item Expression::evaluateSingleton(const DynamicContext::Ptr &context) const
+{
+    return Boolean::fromValue(evaluateEBV(context));
+}
+
+bool Expression::evaluateEBV(const DynamicContext::Ptr &context) const
+{
+    return Boolean::evaluateEBV(evaluateSequence(context), context);
+}
+
+void Expression::evaluateToSequenceReceiver(const DynamicContext::Ptr &context) const
+{
+    QAbstractXmlReceiver *const receiver = context->outputReceiver();
+    const Item::Iterator::Ptr it(evaluateSequence(context));
+    Item next(it->next());
+
+    while(next)
+    {
+        receiver->item(next);
+        next = it->next();
+    }
+}
+
+ItemType::Ptr Expression::expectedContextItemType() const
+{
+    Q_ASSERT_X(false, Q_FUNC_INFO,
+               "expectedContextItemType() must be overridden when RequiresContextItem is set.");
+    return ItemType::Ptr();
+}
+
+Expression::Properties Expression::properties() const
+{
+    return Properties();
+}
+
+Expression::Properties Expression::dependencies() const
+{
+    OperandsIterator it(Ptr(const_cast<Expression *>(this)), OperandsIterator::ExcludeParent);
+    Expression::Ptr next(it.next());
+
+    Properties dependencies(properties());
+
+    while(next)
+    {
+        dependencies |= next->dependencies();
+        next = it.next();
+    }
+
+    return dependencies & (Expression::RequiresFocus | Expression::IsEvaluated | Expression::DisableElimination);
+}
+
+void Expression::announceFocusType(const ItemType::Ptr &itemType)
+{
+    const Expression::List ops(operands());
+    const int len = ops.count();
+
+    for(int i = 0; i < len; ++i)
+        ops.at(i)->announceFocusType(itemType);
+}
+
+Expression::Properties Expression::deepProperties() const
+{
+    Properties props(properties());
+    const Expression::List ops(operands());
+    const int len = ops.count();
+
+    for(int i = 0; i < len; ++i)
+        props |= ops.at(i)->deepProperties();
+
+    return props;
+}
+
+Expression::ID Expression::id() const
+{
+    return IDIgnorableExpression;
+}
+
+OptimizationPass::List Expression::optimizationPasses() const
+{
+    return OptimizationPass::List();
+}
+
+ItemType::Ptr Expression::newFocusType() const
+{
+    Q_ASSERT_X(false, Q_FUNC_INFO,
+               "This function must be overridden when CreatesFocusForLast is set.");
+    return ItemType::Ptr();
+}
+
+const SourceLocationReflection *Expression::actualReflection() const
+{
+    return this;
+}
+
+QString Expression::description() const
+{
+    return QString::fromLatin1("Expression, id: %1").arg(QString::number(id()));
+}
+
+PatternPriority Expression::patternPriority() const
+{
+    return 0.5;
+}
+
+QT_END_NAMESPACE