Expression::Ptr ExpressionFactory::createExpression(const Tokenizer::Ptr &tokenizer,
const StaticContext::Ptr &context,
const QXmlQuery::QueryLanguage lang,
const SequenceType::Ptr &requiredType,
const QUrl &queryURI,
const QXmlName &initialTemplateName)
{
Q_ASSERT(context);
Q_ASSERT(requiredType);
Q_ASSERT(queryURI.isValid());
Tokenizer::Ptr effectiveTokenizer(tokenizer);
#ifdef Patternist_DEBUG
effectiveTokenizer = Tokenizer::Ptr(new TokenRevealer(queryURI, tokenizer));
#endif
OptimizationPasses::Coordinator::init();
const ParserContext::Ptr info(new ParserContext(context, lang, effectiveTokenizer.data()));
info->initialTemplateName = initialTemplateName;
effectiveTokenizer->setParserContext(info);
const int bisonRetval = XPathparse(info.data());
Q_ASSERT_X(bisonRetval == 0, Q_FUNC_INFO,
"We shouldn't be able to get an error, because we throw exceptions.");
Q_UNUSED(bisonRetval); /* Needed when not compiled in debug mode, since bisonRetval won't
* be used in the Q_ASSERT_X above. */
Expression::Ptr result(info->queryBody);
if(!result)
{
context->error(QtXmlPatterns::tr("A library module cannot be evaluated "
"directly. It must be imported from a "
"main module."),
ReportContext::XPST0003,
QSourceLocation(queryURI, 1, 1));
}
/* Optimization: I think many things are done in the wrong order below. We
* probably want everything typechecked before compressing, since we can
* have references all over the place(variable references, template
* invocations, function callsites). This could even be a source to bugs.
*/
/* Here, we type check user declared functions and global variables. This
* means that variables and functions that are not used are type
* checked(which they otherwise wouldn't have been), and those which are
* used, are type-checked twice, unfortunately. */
const bool hasExternalFocus = context->contextItemType();
if(lang == QXmlQuery::XSLT20)
{
/* Bind xsl:call-template instructions to their template bodies.
*
* We do this before type checking and compressing them, because a
* CallTemplate obviously needs its template before being compressed.
*
* Also, we do this before type checking and compressing user
* functions, since they can contain template call sites.
*/
for(int i = 0; i < info->templateCalls.count(); ++i)
{
CallTemplate *const site = info->templateCalls.at(i)->as<CallTemplate>();
const QXmlName targetName(site->name());
const Template::Ptr t(info->namedTemplates.value(targetName));
if(t)
site->setTemplate(t);
else
{
context->error(QtXmlPatterns::tr("No template by name %1 exists.").arg(formatKeyword(context->namePool(), targetName)),
ReportContext::XTSE0650,
site);
}
}
}
/* Type check and compress user functions. */
{
const UserFunction::List::const_iterator end(info->userFunctions.constEnd());
UserFunction::List::const_iterator it(info->userFunctions.constBegin());
/* If the query has a focus(which is common, in the case of a
* stylesheet), we must ensure that the focus isn't visible in the
* function body. */
StaticContext::Ptr effectiveContext;
if(hasExternalFocus)
{
effectiveContext = StaticContext::Ptr(new StaticFocusContext(ItemType::Ptr(),
context));
}
else
effectiveContext = context;
for(; it != end; ++it)
{
pDebug() << "----- User Function Typecheck -----";
registerLastPath((*it)->body());
/* We will most likely call body()->typeCheck() again, once for
* each callsite. That is, it will be called from
* UserFunctionCallsite::typeCheck(), which will be called
* indirectly when we check the query body. */
const Expression::Ptr typeCheck((*it)->body()->typeCheck(effectiveContext,
(*it)->signature()->returnType()));
/* We don't have to call (*it)->setBody(typeCheck) here since it's
* only used directly below. */
processTreePass(typeCheck, UserFunctionTypeCheck);
pDebug() << "------------------------------";
pDebug() << "----- User Function Compress -----";
const Expression::Ptr comp(typeCheck->compress(effectiveContext));
(*it)->setBody(comp);
processTreePass(comp, UserFunctionCompression);
pDebug() << "------------------------------";
}
}
/* Type check and compress global variables. */
{
const VariableDeclaration::Stack::const_iterator vend(info->variables.constEnd());
VariableDeclaration::Stack::const_iterator vit(info->variables.constBegin());
for(; vit != vend; ++vit)
{
Q_ASSERT(*vit);
/* This is a bit murky, the global variable will have it
* Expression::typeCheck() function called from all its references,
* but we also want to check it here globally, so we do
* typechecking using a proper focus. */
if((*vit)->type == VariableDeclaration::ExternalVariable)
continue;
pDebug() << "----- Global Variable Typecheck -----";
Q_ASSERT((*vit)->expression());
/* We supply ZeroOrMoreItems, meaning the variable can evaluate to anything. */
// FIXME which is a source to bugs
// TODO What about compressing variables?
const Expression::Ptr
nev((*vit)->expression()->typeCheck(context, CommonSequenceTypes::ZeroOrMoreItems));
processTreePass(nev, GlobalVariableTypeCheck);
pDebug() << "------------------------------";
}
}
/* Do all tests specific to XSL-T. */
if(lang == QXmlQuery::XSLT20)
{
/* Type check and compress named templates. */
{
pDebug() << "Have " << info->namedTemplates.count() << "named templates";
QMutableHashIterator<QXmlName, Template::Ptr> it(info->namedTemplates);
while(it.hasNext())
{
it.next();
processNamedTemplate(it.key(), it.value()->body, TemplateInitial);
it.value()->body = it.value()->body->typeCheck(context, CommonSequenceTypes::ZeroOrMoreItems);
processNamedTemplate(it.key(), it.value()->body, TemplateTypeCheck);
it.value()->body = it.value()->body->compress(context);
processNamedTemplate(it.key(), it.value()->body, TemplateCompress);
it.value()->compileParameters(context);
}
}
/* Type check and compress template rules. */
{
QHashIterator<QXmlName, TemplateMode::Ptr> it(info->templateRules);
/* Since a pattern can exist of AxisStep, its typeCheck() stage
* requires a focus. In the case that we're invoked with a name but
* no focus, this will yield a compile error, unless we declare a
* focus manually. This only needs to be done for the pattern
* expression, since the static type of the pattern is used as the
* static type for the focus of the template body. */
StaticContext::Ptr patternContext;
if(hasExternalFocus)
patternContext = context;
else
patternContext = StaticContext::Ptr(new StaticFocusContext(BuiltinTypes::node, context));
/* For each template pattern. */
while(it.hasNext())
{
it.next();
const TemplateMode::Ptr &mode = it.value();
const int len = mode->templatePatterns.count();
TemplatePattern::ID currentTemplateID = -1;
bool hasDoneItOnce = false;
/* For each template pattern. */
for(int i = 0; i < len; ++i)
{
/* We can't use references for these two members, since we
* assign to them. */
const TemplatePattern::Ptr &pattern = mode->templatePatterns.at(i);
Expression::Ptr matchPattern(pattern->matchPattern());
processTemplateRule(pattern->templateTarget()->body,
pattern, mode->name(), TemplateInitial);
matchPattern = matchPattern->typeCheck(patternContext, CommonSequenceTypes::ZeroOrMoreItems);
matchPattern = matchPattern->compress(patternContext);
pattern->setMatchPattern(matchPattern);
if(currentTemplateID == -1 && hasDoneItOnce)
{
currentTemplateID = pattern->id();
continue;
}
else if(currentTemplateID == pattern->id() && hasDoneItOnce)
{
hasDoneItOnce = false;
continue;
}
hasDoneItOnce = true;
currentTemplateID = pattern->id();
Expression::Ptr body(pattern->templateTarget()->body);
/* Patterns for a new template has started, we must
* deal with the body & parameters. */
{
/* TODO type is wrong, it has to be the union of all
* patterns. */
const StaticContext::Ptr focusContext(new StaticFocusContext(matchPattern->staticType()->itemType(),
context));
body = body->typeCheck(focusContext, CommonSequenceTypes::ZeroOrMoreItems);
pattern->templateTarget()->compileParameters(focusContext);
}
processTemplateRule(body, pattern, mode->name(), TemplateTypeCheck);
body = body->compress(context);
pattern->templateTarget()->body = body;
processTemplateRule(body, pattern, mode->name(), TemplateCompress);
}
mode->finalize();
}
}
/* Add templates in mode #all to all other modes.
*
* We do this after the templates has been typechecked and compressed,
* since otherwise it will be done N times for the built-in templates,
* where N is the count of different templates, instead of once. */
{
const QXmlName nameModeAll(QXmlName(StandardNamespaces::InternalXSLT,
StandardLocalNames::all));
const TemplateMode::Ptr &modeAll = info->templateRules[nameModeAll];
Q_ASSERT_X(modeAll, Q_FUNC_INFO,
"We should at least have the builtin templates.");
QHashIterator<QXmlName, TemplateMode::Ptr> it(info->templateRules);
while(it.hasNext())
{
it.next();
/* Don't add mode #all to mode #all. */
if(it.key() == nameModeAll)
continue;
it.value()->addMode(modeAll);
}
}
}
/* Type check and compress the query body. */
{
pDebug() << "----- Initial AST build. -----";
processTreePass(result, QueryBodyInitial);
pDebug() << "------------------------------";
pDebug() << "----- Type Check -----";
registerLastPath(result);
result->rewrite(result, result->typeCheck(context, requiredType), context);
processTreePass(result, QueryBodyTypeCheck);
pDebug() << "------------------------------";
pDebug() << "----- Compress -----";
result->rewrite(result, result->compress(context), context);
processTreePass(result, QueryBodyCompression);
pDebug() << "------------------------------";
}
return result;
}
Expression::Ptr ExpressionFactory::createExpression(const QString &expr,
const StaticContext::Ptr &context,
const LanguageAccent lang,
const SequenceType::Ptr &requiredType,
const QUrl &queryURI)
{
pDebug() << Q_FUNC_INFO << queryURI;
Q_ASSERT(context);
Q_ASSERT(requiredType);
Q_ASSERT(queryURI.isValid());
OptimizationPasses::Coordinator::init();
ParserContext::Ptr info(new ParserContext(context, lang,
Tokenizer::Ptr(new XQueryTokenizer(expr, queryURI))));
const int bisonRetval = XPathparse(info.data());
Q_ASSERT_X(bisonRetval == 0, Q_FUNC_INFO,
"We shouldn't be able to get an error, because we throw exceptions.");
Q_UNUSED(bisonRetval); /* Needed when not compiled in debug mode, since bisonRetval won't
* be used in the Q_ASSERT_X above. */
Expression::Ptr result(info->queryBody);
if(!result)
{
context->error(QtXmlPatterns::tr("A library module cannot be evaluated "
"directly. It must be imported from a "
"main module."),
ReportContext::XPST0003,
QSourceLocation(queryURI, 1, 1));
}
/* Here, we type check user declared functions and global variables. This means
* that variables and functions that are not used are type checked(which they otherwise
* wouldn't have been), and those which are used, are type-checked twice, unfortunately. */
const UserFunction::List::const_iterator end(info->userFunctions.constEnd());
UserFunction::List::const_iterator it(info->userFunctions.constBegin());
for(; it != end; ++it)
{
pDebug() << "----- User Function Typecheck -----";
registerLastPath((*it)->body());
/* We will most likely call body()->typeCheck() again, once for each callsite. That is, it will
* be called from UserFunctionCallsite::typeCheck(), which will be called indirectly when
* we check the query body. */
const Expression::Ptr typeCheck((*it)->body()->typeCheck(context, (*it)->signature()->returnType()));
/* We don't have to call (*it)->setBody(typeCheck) here since it's only used directly below. */
processTreePass(typeCheck, UserFunctionTypeCheck);
pDebug() << "------------------------------";
pDebug() << "----- User Function Compress -----";
const Expression::Ptr comp(typeCheck->compress(context));
(*it)->setBody(comp);
processTreePass(comp, UserFunctionCompression);
pDebug() << "------------------------------";
}
const VariableDeclaration::Stack::const_iterator vend(info->variables.constEnd());
VariableDeclaration::Stack::const_iterator vit(info->variables.constBegin());
for(; vit != vend; ++vit)
{
Q_ASSERT(*vit);
/* If it's already used, it will be typeChecked later on. */
if((*vit)->isUsed() || (*vit)->type == VariableDeclaration::ExternalVariable)
continue;
pDebug() << "----- Global Variable Typecheck -----";
Q_ASSERT((*vit)->expression());
/* We supply ZeroOrMoreItems, meaning the variable can evaluate to anything. */
// FIXME which is a source to bugs
// TODO What about compressing variables?
const Expression::Ptr
nev((*vit)->expression()->typeCheck(context, CommonSequenceTypes::ZeroOrMoreItems));
processTreePass(nev, GlobalVariableTypeCheck);
pDebug() << "------------------------------";
}
pDebug() << "----- Initial AST build. -----";
processTreePass(result, QueryBodyInitial);
pDebug() << "------------------------------";
pDebug() << "----- Type Check -----";
registerLastPath(result);
result->rewrite(result, result->typeCheck(context, requiredType), context);
processTreePass(result, QueryBodyTypeCheck);
pDebug() << "------------------------------";
pDebug() << "----- Compress -----";
result->rewrite(result, result->compress(context), context);
processTreePass(result, QueryBodyCompression);
pDebug() << "------------------------------";
return result;
}