src/xmlpatterns/parser/qparsercontext_p.h
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     1 /****************************************************************************
       
     2 **
       
     3 ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
       
     4 ** All rights reserved.
       
     5 ** Contact: Nokia Corporation (qt-info@nokia.com)
       
     6 **
       
     7 ** This file is part of the QtXmlPatterns module of the Qt Toolkit.
       
     8 **
       
     9 ** $QT_BEGIN_LICENSE:LGPL$
       
    10 ** No Commercial Usage
       
    11 ** This file contains pre-release code and may not be distributed.
       
    12 ** You may use this file in accordance with the terms and conditions
       
    13 ** contained in the Technology Preview License Agreement accompanying
       
    14 ** this package.
       
    15 **
       
    16 ** GNU Lesser General Public License Usage
       
    17 ** Alternatively, this file may be used under the terms of the GNU Lesser
       
    18 ** General Public License version 2.1 as published by the Free Software
       
    19 ** Foundation and appearing in the file LICENSE.LGPL included in the
       
    20 ** packaging of this file.  Please review the following information to
       
    21 ** ensure the GNU Lesser General Public License version 2.1 requirements
       
    22 ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
       
    23 **
       
    24 ** In addition, as a special exception, Nokia gives you certain additional
       
    25 ** rights.  These rights are described in the Nokia Qt LGPL Exception
       
    26 ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
       
    27 **
       
    28 ** If you have questions regarding the use of this file, please contact
       
    29 ** Nokia at qt-info@nokia.com.
       
    30 **
       
    31 **
       
    32 **
       
    33 **
       
    34 **
       
    35 **
       
    36 **
       
    37 **
       
    38 ** $QT_END_LICENSE$
       
    39 **
       
    40 ****************************************************************************/
       
    41 
       
    42 //
       
    43 //  W A R N I N G
       
    44 //  -------------
       
    45 //
       
    46 // This file is not part of the Qt API.  It exists purely as an
       
    47 // implementation detail.  This header file may change from version to
       
    48 // version without notice, or even be removed.
       
    49 //
       
    50 // We mean it.
       
    51 
       
    52 #ifndef Patternist_ParserContext_H
       
    53 #define Patternist_ParserContext_H
       
    54 
       
    55 #include <QFlags>
       
    56 #include <QSharedData>
       
    57 #include <QStack>
       
    58 #include <QStringList>
       
    59 #include <QtGlobal>
       
    60 #include <QXmlQuery>
       
    61 
       
    62 #include "qbuiltintypes_p.h"
       
    63 #include "qfunctionsignature_p.h"
       
    64 #include "qorderby_p.h"
       
    65 #include "qtemplatemode_p.h"
       
    66 #include "quserfunctioncallsite_p.h"
       
    67 #include "quserfunction_p.h"
       
    68 #include "qvariabledeclaration_p.h"
       
    69 
       
    70 QT_BEGIN_HEADER
       
    71 
       
    72 QT_BEGIN_NAMESPACE
       
    73 
       
    74 namespace QPatternist
       
    75 {
       
    76     class Tokenizer;
       
    77 
       
    78     /**
       
    79      * @short Contains data used when parsing and tokenizing.
       
    80      *
       
    81      * When ExpressionFactory::create() is called, an instance of this class
       
    82      * is passed to the scanner and parser. It holds all information that is
       
    83      * needed to create the expression.
       
    84      *
       
    85      * @author Frans Englich <frans.englich@nokia.com>
       
    86      */
       
    87     class ParserContext : public QSharedData
       
    88     {
       
    89     public:
       
    90         typedef QExplicitlySharedDataPointer<ParserContext> Ptr;
       
    91 
       
    92         enum PrologDeclaration
       
    93         {
       
    94             BoundarySpaceDecl               = 1,
       
    95             DefaultCollationDecl            = 2,
       
    96             BaseURIDecl                     = 4,
       
    97             ConstructionDecl                = 8,
       
    98             OrderingModeDecl                = 16,
       
    99             EmptyOrderDecl                  = 32,
       
   100             CopyNamespacesDecl              = 64,
       
   101             DeclareDefaultElementNamespace  = 128,
       
   102             DeclareDefaultFunctionNamespace = 256
       
   103         };
       
   104 
       
   105         typedef QFlags<PrologDeclaration> PrologDeclarations;
       
   106 
       
   107         /**
       
   108          * Constructs a ParserContext instance.
       
   109          *
       
   110          * @param context the static context as defined in XPath. This contain
       
   111          * namespace bindings, error handler, and other information necessary
       
   112          * for creating an XPath expression.
       
   113          * @param lang the particular XPath language sub-set that should be parsed
       
   114          * @param tokenizer the Tokenizer to use.
       
   115          * @see ExpressionFactory::LanguageAccent
       
   116          */
       
   117         ParserContext(const StaticContext::Ptr &context,
       
   118                       const QXmlQuery::QueryLanguage lang,
       
   119                       Tokenizer *const tokenizer);
       
   120 
       
   121         /**
       
   122          * @short Removes the recently pushed variables from
       
   123          * scope. The amount of removed variables is @p amount.
       
   124          *
       
   125          * finalizePushedVariable() can be seen as popping the variable.
       
   126          *
       
   127          */
       
   128         void finalizePushedVariable(const int amount = 1,
       
   129                                     const bool shouldPop = true);
       
   130 
       
   131         inline VariableSlotID allocatePositionalSlot()
       
   132         {
       
   133             ++m_positionSlot;
       
   134             return m_positionSlot;
       
   135         }
       
   136 
       
   137         inline VariableSlotID allocateExpressionSlot()
       
   138         {
       
   139             const VariableSlotID retval = m_expressionSlot;
       
   140             ++m_expressionSlot;
       
   141             return retval;
       
   142         }
       
   143 
       
   144         inline VariableSlotID allocateGlobalVariableSlot()
       
   145         {
       
   146             ++m_globalVariableSlot;
       
   147             return m_globalVariableSlot;
       
   148         }
       
   149 
       
   150         inline bool hasDeclaration(const PrologDeclaration decl) const
       
   151         {
       
   152             return m_prologDeclarations.testFlag(decl);
       
   153         }
       
   154 
       
   155         inline void registerDeclaration(const PrologDeclaration decl)
       
   156         {
       
   157             m_prologDeclarations |= decl;
       
   158         }
       
   159 
       
   160         /**
       
   161          * The namespaces declared with <tt>declare namespace</tt>.
       
   162          */
       
   163         QStringList declaredPrefixes;
       
   164 
       
   165         /**
       
   166          * This is a temporary stack, used for keeping variables in scope,
       
   167          * such as for function arguments & let clauses.
       
   168          */
       
   169         VariableDeclaration::Stack variables;
       
   170 
       
   171         inline bool isXSLT() const
       
   172         {
       
   173             return languageAccent == QXmlQuery::XSLT20;
       
   174         }
       
   175 
       
   176         const StaticContext::Ptr staticContext;
       
   177         /**
       
   178          * We don't store a Tokenizer::Ptr here, because then we would get a
       
   179          * circular referencing between ParserContext and XSLTTokenizer, and
       
   180          * hence they would never destruct.
       
   181          */
       
   182         Tokenizer *const tokenizer;
       
   183         const QXmlQuery::QueryLanguage languageAccent;
       
   184 
       
   185         /**
       
   186          * Only used in the case of XSL-T. Is the name of the initial template
       
   187          * to call. If null, no name was provided, and regular template
       
   188          * matching should be done.
       
   189          */
       
   190         QXmlName initialTemplateName;
       
   191 
       
   192         /**
       
   193          * Used when parsing direct element constructors. It is used
       
   194          * for ensuring tags are well-balanced.
       
   195          */
       
   196         QStack<QXmlName> tagStack;
       
   197 
       
   198         /**
       
   199          * The actual expression, the Query. This member may be @c null,
       
   200          * such as in the case of an XQuery library module.
       
   201          */
       
   202         Expression::Ptr queryBody;
       
   203 
       
   204         /**
       
   205          * The user functions declared in the prolog.
       
   206          */
       
   207         UserFunction::List userFunctions;
       
   208 
       
   209         /**
       
   210          * Contains all calls to user defined functions.
       
   211          */
       
   212         UserFunctionCallsite::List userFunctionCallsites;
       
   213 
       
   214         /**
       
   215          * All variables declared with <tt>declare variable</tt>.
       
   216          */
       
   217         VariableDeclaration::List declaredVariables;
       
   218 
       
   219         inline VariableSlotID currentPositionSlot() const
       
   220         {
       
   221             return m_positionSlot;
       
   222         }
       
   223 
       
   224         inline VariableSlotID currentExpressionSlot() const
       
   225         {
       
   226             return m_expressionSlot;
       
   227         }
       
   228 
       
   229         inline void restoreNodeTestSource()
       
   230         {
       
   231             nodeTestSource = BuiltinTypes::element;
       
   232         }
       
   233 
       
   234         inline VariableSlotID allocateCacheSlot()
       
   235         {
       
   236             return ++m_evaluationCacheSlot;
       
   237         }
       
   238 
       
   239         inline VariableSlotID allocateCacheSlots(const int count)
       
   240         {
       
   241             const VariableSlotID retval = m_evaluationCacheSlot + 1;
       
   242             m_evaluationCacheSlot += count + 1;
       
   243             return retval;
       
   244         }
       
   245 
       
   246         ItemType::Ptr nodeTestSource;
       
   247 
       
   248         QStack<Expression::Ptr> typeswitchSource;
       
   249 
       
   250         /**
       
   251          * The library module namespace set with <tt>declare module</tt>.
       
   252          */
       
   253         QXmlName::NamespaceCode moduleNamespace;
       
   254 
       
   255         /**
       
   256          * When a direct element constructor is processed, resolvers are
       
   257          * created in order to carry the namespace declarations. In such case,
       
   258          * the old resolver is pushed here.
       
   259          */
       
   260         QStack<NamespaceResolver::Ptr> resolvers;
       
   261 
       
   262         /**
       
   263          * This is used for handling the following obscene case:
       
   264          *
       
   265          * - <tt>\<e\>{1}{1}\<\/e\></tt> produce <tt>\<e\>11\</e\></tt>
       
   266          * - <tt>\<e\>{1, 1}\<\/e\></tt> produce <tt>\<e\>1 1\</e\></tt>
       
   267          *
       
   268          * This boolean tracks whether the previous reduction inside element
       
   269          * content was done with an enclosed expression.
       
   270          */
       
   271         bool isPreviousEnclosedExpr;
       
   272 
       
   273         int elementConstructorDepth;
       
   274 
       
   275         QStack<bool> scanOnlyStack;
       
   276 
       
   277         QStack<OrderBy::Stability> orderStability;
       
   278 
       
   279         /**
       
   280          * Whether any prolog declaration that must occur after the first
       
   281          * group has been encountered.
       
   282          */
       
   283         bool hasSecondPrologPart;
       
   284 
       
   285         bool preserveNamespacesMode;
       
   286         bool inheritNamespacesMode;
       
   287 
       
   288         /**
       
   289          * Contains all named templates. Since named templates
       
   290          * can also have rules, each body may also be in templateRules.
       
   291          */
       
   292         QHash<QXmlName, Template::Ptr>  namedTemplates;
       
   293 
       
   294         /**
       
   295          * All the @c xsl:call-template instructions that we have encountered.
       
   296          */
       
   297         QVector<Expression::Ptr>         templateCalls;
       
   298 
       
   299         /**
       
   300          * If we're in XSL-T, and a variable reference is encountered
       
   301          * which isn't in-scope, it's added to this hash since a global
       
   302          * variable declaration may appear later on.
       
   303          *
       
   304          * We use a multi hash, since we can encounter several references to
       
   305          * the same variable before it's declared.
       
   306          */
       
   307         QMultiHash<QXmlName, Expression::Ptr> unresolvedVariableReferences;
       
   308 
       
   309         /**
       
   310          *
       
   311          * Contains the encountered template rules, as opposed
       
   312          * to named templates.
       
   313          *
       
   314          * The key is the name of the template mode. If it's a default
       
   315          * constructed value, it's the default mode.
       
   316          *
       
   317          * Since templates rules may also be named, each body may also be in
       
   318          * namedTemplates.
       
   319          *
       
   320          * To be specific, the values are not the templates, the values are
       
   321          * modes, and the TemplateMode contains the patterns and bodies.
       
   322          */
       
   323         QHash<QXmlName, TemplateMode::Ptr>  templateRules;
       
   324 
       
   325         /**
       
   326          * @short Returns the TemplateMode for @p modeName or @c null if the
       
   327          * mode being asked for is @c #current.
       
   328          */
       
   329         TemplateMode::Ptr modeFor(const QXmlName &modeName)
       
   330         {
       
   331             /* #current is not a mode, so it cannot contain templates. #current
       
   332              * specifies how to look up templates wrt. mode. This check helps
       
   333              * code that calls us, asking for the mode it needs to lookup in.
       
   334              */
       
   335             if(modeName == QXmlName(StandardNamespaces::InternalXSLT, StandardLocalNames::current))
       
   336                 return TemplateMode::Ptr();
       
   337 
       
   338             TemplateMode::Ptr &mode = templateRules[modeName];
       
   339 
       
   340             if(!mode)
       
   341                 mode = TemplateMode::Ptr(new TemplateMode(modeName));
       
   342 
       
   343             Q_ASSERT(templateRules[modeName]);
       
   344             return mode;
       
   345         }
       
   346 
       
   347         inline TemplatePattern::ID allocateTemplateID()
       
   348         {
       
   349             ++m_currentTemplateID;
       
   350             return m_currentTemplateID;
       
   351         }
       
   352 
       
   353         /**
       
   354          * The @c xsl:param appearing inside template.
       
   355          */
       
   356         VariableDeclaration::List templateParameters;
       
   357 
       
   358         /**
       
   359          * The @c xsl:with-param appearing in template calling instruction.
       
   360          */
       
   361         WithParam::Hash templateWithParams;
       
   362 
       
   363         inline void templateParametersHandled()
       
   364         {
       
   365             finalizePushedVariable(templateParameters.count());
       
   366             templateParameters.clear();
       
   367         }
       
   368 
       
   369         inline void templateWithParametersHandled()
       
   370         {
       
   371             templateWithParams.clear();
       
   372         }
       
   373 
       
   374         inline bool isParsingWithParam() const
       
   375         {
       
   376             return m_isParsingWithParam.top();
       
   377         }
       
   378 
       
   379         void startParsingWithParam()
       
   380         {
       
   381             m_isParsingWithParam.push(true);
       
   382         }
       
   383 
       
   384         void endParsingWithParam()
       
   385         {
       
   386             m_isParsingWithParam.pop();
       
   387         }
       
   388 
       
   389         /**
       
   390          * This is used to deal with XSL-T's exception to the @c node() type,
       
   391          * which doesn't match document nodes.
       
   392          */
       
   393         bool                                isParsingPattern;
       
   394 
       
   395         ImportPrecedence                    currentImportPrecedence;
       
   396 
       
   397         bool isFirstTemplate() const
       
   398         {
       
   399             return m_currentTemplateID == InitialTemplateID;
       
   400         }
       
   401 
       
   402         /**
       
   403          * Whether we're processing XSL-T 1.0 code.
       
   404          */
       
   405         QStack<bool> isBackwardsCompat;
       
   406 
       
   407     private:
       
   408         enum
       
   409         {
       
   410             InitialTemplateID = -1
       
   411         };
       
   412 
       
   413         VariableSlotID                      m_evaluationCacheSlot;
       
   414         VariableSlotID                      m_expressionSlot;
       
   415         VariableSlotID                      m_positionSlot;
       
   416         PrologDeclarations                  m_prologDeclarations;
       
   417         VariableSlotID                      m_globalVariableSlot;
       
   418         TemplatePattern::ID                 m_currentTemplateID;
       
   419 
       
   420         /**
       
   421          * The default is @c false. If we're not parsing @c xsl:with-param,
       
   422          * hence parsing @c xsl:param, the value has changed.
       
   423          */
       
   424         QStack<bool>                        m_isParsingWithParam;
       
   425         Q_DISABLE_COPY(ParserContext)
       
   426     };
       
   427 }
       
   428 
       
   429 QT_END_NAMESPACE
       
   430 
       
   431 QT_END_HEADER
       
   432 
       
   433 #endif