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39
40#include "qcommonsequencetypes_p.h"
41#include "qdynamiccontextstore_p.h"
42#include "qevaluationcache_p.h"
43
44#include "quserfunctioncallsite_p.h"
45
46QT_BEGIN_NAMESPACE
47
48using namespace QPatternist;
49
50UserFunctionCallsite::UserFunctionCallsite(const QXmlName nameP,
51 const FunctionSignature::Arity ar) : CallSite(nameP)
52 , m_arity(ar)
53 , m_expressionSlotOffset(-2)
54
55{
56}
57
58Item::Iterator::Ptr UserFunctionCallsite::evaluateSequence(const DynamicContext::Ptr &context) const
59{
60 return m_body->evaluateSequence(context: bindVariables(context));
61}
62
63Item UserFunctionCallsite::evaluateSingleton(const DynamicContext::Ptr &context) const
64{
65 return m_body->evaluateSingleton(context: bindVariables(context));
66}
67
68bool UserFunctionCallsite::evaluateEBV(const DynamicContext::Ptr &context) const
69{
70 return m_body->evaluateEBV(context: bindVariables(context));
71}
72
73void UserFunctionCallsite::evaluateToSequenceReceiver(const DynamicContext::Ptr &context) const
74{
75 m_body->evaluateToSequenceReceiver(context: bindVariables(context));
76}
77
78DynamicContext::Ptr UserFunctionCallsite::bindVariables(const DynamicContext::Ptr &context) const
79{
80 const DynamicContext::Ptr stackContext(context->createStack());
81 Q_ASSERT(stackContext);
82
83 const Expression::List::const_iterator end(m_operands.constEnd());
84 Expression::List::const_iterator it(m_operands.constBegin());
85
86 VariableSlotID slot = m_expressionSlotOffset;
87
88 for(; it != end; ++it)
89 {
90 stackContext->setExpressionVariable(slot,
91 newValue: Expression::Ptr(new DynamicContextStore(*it, context)));
92 ++slot;
93 }
94
95 return stackContext;
96}
97
98SequenceType::List UserFunctionCallsite::expectedOperandTypes() const
99{
100 SequenceType::List result;
101
102 if(m_functionDeclaration)
103 {
104 const FunctionArgument::List args(m_functionDeclaration->signature()->arguments());
105 const FunctionArgument::List::const_iterator end(args.constEnd());
106 FunctionArgument::List::const_iterator it(args.constBegin());
107
108 for(; it != end; ++it)
109 result.append(t: (*it)->type());
110 }
111 else
112 result.append(t: CommonSequenceTypes::ZeroOrMoreItems);
113
114 return result;
115}
116
117Expression::Ptr UserFunctionCallsite::typeCheck(const StaticContext::Ptr &context,
118 const SequenceType::Ptr &reqType)
119{
120 /* The parser calls TypeChecker::applyFunctionConversion() on user function
121 * bodies, possibly indirectly, before all function call sites have been
122 * resolved. Hence it's possible that we're called before before the usual
123 * typeCheck() pass, and hence before we have been resolved/checked and
124 * subsequently m_functionDeclaration set. Therefore, encounter for that below.
125 *
126 * UnresolvedVariableReference::typeCheck() has the same dilemma.
127 */
128
129 /* Ensure that the return value of the function is properly
130 * converted/does match from where it is called(which is here). */
131 if(isRecursive() || !m_functionDeclaration)
132 return CallSite::typeCheck(context, reqType);
133 else
134 {
135 /* Update, such that we use a recent version of the body that has typeCheck()
136 * and compress() rewrites included. */
137 m_body = m_functionDeclaration->body();
138
139 /* Note, we can't assign to m_functionDeclaration->body() because UserFunction can apply
140 * to several different callsites. Hence we need our own version. */
141 m_body = m_body->typeCheck(context, reqType);
142
143 /* We just act as a pipe for m_body, so we don't have to typecheck ourselves. However,
144 * the arguments must match the function declaration. */
145 typeCheckOperands(context);
146 return Expression::Ptr(this);
147 }
148}
149
150Expression::Ptr UserFunctionCallsite::compress(const StaticContext::Ptr &context)
151{
152 if(!isRecursive())
153 rewrite(old&: m_body, New: m_body->compress(context), context);
154
155 return CallSite::compress(context);
156}
157
158Expression::Properties UserFunctionCallsite::properties() const
159{
160 return DisableElimination;
161}
162
163SequenceType::Ptr UserFunctionCallsite::staticType() const
164{
165 /* Our return type, is the static type of the function body. We could have also used
166 * m_functionDeclaration->signature()->returnType(), but it doesn't get updated
167 * when function conversion is applied.
168 * We can't use m_body's type if we're recursive, because m_body computes its type
169 * from its children, and we're at least one of the children. Hence, we would
170 * recurse infinitely if we did.
171 *
172 * m_body can be null here if we're called before setSource().
173 */
174 if(isRecursive() || !m_body)
175 return CommonSequenceTypes::ZeroOrMoreItems; // TODO use the declaration, it can have a type explicitly.
176 else
177 return m_body->staticType();
178}
179
180ExpressionVisitorResult::Ptr UserFunctionCallsite::accept(const ExpressionVisitor::Ptr &visitor) const
181{
182 return visitor->visit(this);
183}
184
185Expression::ID UserFunctionCallsite::id() const
186{
187 return IDUserFunctionCallsite;
188}
189
190bool UserFunctionCallsite::isSignatureValid(const FunctionSignature::Ptr &sign) const
191{
192 Q_ASSERT(sign);
193
194 return sign->name() == name()
195 &&
196 sign->isArityValid(arity: m_arity);
197}
198
199bool UserFunctionCallsite::configureRecursion(const CallTargetDescription::Ptr &sign)
200{
201 Q_ASSERT(sign);
202
203 setIsRecursive(isSignatureValid(sign));
204 return isRecursive();
205}
206
207void UserFunctionCallsite::setSource(const UserFunction::Ptr &userFunction,
208 const VariableSlotID cacheSlotOffset)
209{
210 m_functionDeclaration = userFunction;
211 m_body = userFunction->body();
212 m_expressionSlotOffset = userFunction->expressionSlotOffset();
213
214 const int len = m_operands.size();
215
216 const VariableDeclaration::List varDecls(userFunction->argumentDeclarations());
217
218 for(int i = 0; i < len; ++i)
219 {
220 /* We don't want evaluation caches for range variables, it's not necessary since
221 * the item is already cached in DynamicContext::rangeVariable(). */
222 if(m_operands.at(i)->is(i: IDRangeVariableReference))
223 continue;
224
225 /* Note that we pass in cacheSlotOffset + i here instead of varDecls.at(i)->slot since
226 * we want independent caches for each callsite. */
227 m_operands[i] = Expression::Ptr(new EvaluationCache<false>(m_operands.at(i),
228 varDecls.at(i),
229 cacheSlotOffset + i));
230 }
231}
232
233FunctionSignature::Arity UserFunctionCallsite::arity() const
234{
235 return m_arity;
236}
237
238CallTargetDescription::Ptr UserFunctionCallsite::callTargetDescription() const
239{
240 return m_functionDeclaration->signature();
241}
242
243QT_END_NAMESPACE
244

source code of qtxmlpatterns/src/xmlpatterns/expr/quserfunctioncallsite.cpp