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The XSLT and XQuery Processor
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2018-2022 Saxonica Limited
// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
// If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
// This Source Code Form is "Incompatible With Secondary Licenses", as defined by the Mozilla Public License, v. 2.0.
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
package net.sf.saxon.expr.parser;
import net.sf.saxon.expr.Expression;
import net.sf.saxon.expr.Literal;
import net.sf.saxon.expr.StaticProperty;
import net.sf.saxon.om.AxisInfo;
import net.sf.saxon.om.Item;
import net.sf.saxon.trans.Err;
import net.sf.saxon.type.ItemType;
import net.sf.saxon.type.TypeHierarchy;
import net.sf.saxon.type.UType;
import net.sf.saxon.value.SequenceType;
import java.util.Optional;
/**
* A RoleDiagnostic (formerly RoleLocator) identifies the role in which an expression is used,
* for example as the third argument of the concat() function. This information is stored in an
* ItemChecker or CardinalityChecker so that good diagnostics can be
* achieved when run-time type errors are detected.
*/
public class RoleDiagnostic {
private final int kind;
private final String operation;
private final int operand;
private String errorCode = "XPTY0004"; // default error code for type errors
public static final int FUNCTION = 0;
public static final int BINARY_EXPR = 1;
public static final int TYPE_OP = 2;
public static final int VARIABLE = 3;
public static final int INSTRUCTION = 4;
public static final int FUNCTION_RESULT = 5;
public static final int ORDER_BY = 6;
public static final int TEMPLATE_RESULT = 7;
public static final int PARAM = 8;
public static final int UNARY_EXPR = 9;
public static final int UPDATING_EXPR = 10;
//public static final int GROUPING_KEY = 11; // 9.8 and earlier
public static final int EVALUATE_RESULT = 12;
public static final int CONTEXT_ITEM = 13;
public static final int AXIS_STEP = 14;
public static final int OPTION = 15;
public static final int CHARACTER_MAP_EXPANSION = 16;
public static final int FOR_MEMBER = 17;
//public static final int DOCUMENT_ORDER = 17; // 9.8 and earlier
//public static final int MAP_CONSTRUCTOR = 18; // 9.8 and earlier
public static final int MATCH_PATTERN = 19;
public static final int MISC = 20;
/**
* Create information about the role of a subexpression within its parent expression
*
* @param kind the kind of parent expression, e.g. a function call or a variable reference
* @param operation the name of the object in the parent expression, e.g. a function name or
* instruction name. A QName is provided in display form, prefix:local.
* For a string, the special format element/attribute is recognized, for example xsl:for-each/select,
* to identify the role of an XPath expression in a stylesheet.
* @param operand Ordinal position of this subexpression, e.g. the position of an argument in
* a function call
*/
public RoleDiagnostic(int kind, String operation, int operand) {
this.kind = kind;
this.operation = operation;
this.operand = operand;
}
/**
* Set the error code to be produced if a type error is detected
*
* @param code The error code
*/
public void setErrorCode(/*@Nullable*/ String code) {
if (code != null) {
this.errorCode = code;
}
}
/**
* Get the error code to be produced if a type error is detected
*
* @return code The error code
*/
public String getErrorCode() {
return errorCode;
}
/**
* Ask whether the error code represents a type error
*
* @return true if the error is treated as a type error
*/
public boolean isTypeError() {
return !errorCode.startsWith("FORG") && !errorCode.equals("XPDY0050");
}
/**
* Construct and return the error message indicating a type error
*
* @return the constructed error message
*/
public String getMessage() {
String name = operation;
switch (kind) {
case FUNCTION:
if (name.equals("saxon:call") || name.equals("saxon:apply")) {
if (operand == 0) {
return "target of the dynamic function call";
} else {
return ordinal(operand) + " argument of the dynamic function call";
}
} else {
return ordinal(operand + 1) + " argument of " +
(name.isEmpty() ? "the anonymous function" : name + "()");
}
case BINARY_EXPR:
return ordinal(operand + 1) + " operand of '" + name + '\'';
case UNARY_EXPR:
return "operand of '-'";
case TYPE_OP:
return "value in '" + name + "' expression";
case VARIABLE:
if (name.equals("saxon:context-item")) {
return "context item";
} else {
return "value of variable $" + name;
}
case INSTRUCTION:
int slash = name.indexOf('/');
String attributeName = "";
if (slash >= 0) {
attributeName = name.substring(slash + 1);
name = name.substring(0, slash);
}
return "@" + attributeName + " attribute of " + (name.equals("LRE") ? "a literal result element" : name);
case FUNCTION_RESULT:
if (name.isEmpty()) {
return "result of the anonymous function";
} else {
return "result of a call to " + name;
}
case TEMPLATE_RESULT:
return "result of template " + name;
case ORDER_BY:
return ordinal(operand + 1) + " sort key";
case PARAM:
return "value of parameter $" + name;
case UPDATING_EXPR:
return "value of the " + ordinal(operand + 1) + " operand of " + name + " expression";
case EVALUATE_RESULT:
return "result of the expression {" + name + "} evaluated by xsl:evaluate";
case CONTEXT_ITEM:
return "context item";
case AXIS_STEP:
return "context item for the " + AxisInfo.axisName[operand] + " axis";
case OPTION:
return "value of the " + name + " option";
case CHARACTER_MAP_EXPANSION:
return "substitute value for character '" + name + "' in the character map";
case FOR_MEMBER:
return "'for member $" + name + "' expression";
case MATCH_PATTERN:
return "match pattern";
case MISC:
return operation;
default:
return "";
}
}
/**
* Construct the part of the message giving the required item type
*
* @param requiredItemType the item type required by the context of a particular expression
* @return a message of the form "Required item type of X is Y"
*/
public String composeRequiredMessage(ItemType requiredItemType) {
return "The required item type of the " + getMessage() +
" is " + requiredItemType;
}
/**
* Construct a full error message
*
* @param requiredItemType the item type required by the context of a particular expression
* @param suppliedItemType the item type inferred by static analysis of an expression
* @return a message of the form "Required item type of A is R; supplied value has item type S"
*/
public String composeErrorMessage(ItemType requiredItemType, ItemType suppliedItemType) {
return composeRequiredMessage(requiredItemType) +
"; supplied value has item type " +
suppliedItemType;
}
/**
* Construct a full error message, containing the supplied expression (for use when
* the error is reported statically)
*
* @param requiredItemType the item type required by the context of a particular expression
* @param supplied the supplied expression
* @param th the type hierarchy
* @return a message of the form "Required item type of A is R; supplied value has item type S"
*/
public String composeErrorMessage(ItemType requiredItemType, Expression supplied, TypeHierarchy th) {
if (supplied instanceof Literal) {
String s = composeRequiredMessage(requiredItemType);
Optional more = SequenceType.makeSequenceType(requiredItemType, StaticProperty.ALLOWS_ZERO_OR_MORE)
.explainMismatch(((Literal)supplied).getGroundedValue(), th);
if (more.isPresent()) {
s = s + ". " + more.get();
}
return s;
}
return composeRequiredMessage(requiredItemType) +
", but the supplied expression {" + supplied.toShortString() + "} has item type " +
supplied.getItemType();
}
/**
* Construct a full error message, displaying the item in error (suitable for use when
* a type error is reported dynamically)
*
* @param requiredItemType the item type required by the context of a particular expression
* @param item the actual item in error. Must NOT be null (unlike earlier releases).
* @param th the type hierarchy
* @return a message of the form "Required item type of A is R; supplied value has item type S"
*/
public String composeErrorMessage(ItemType requiredItemType, Item item, TypeHierarchy th) {
StringBuilder message = new StringBuilder(256);
message.append(composeRequiredMessage(requiredItemType));
message.append("; the supplied value ");
message.append(Err.depict(item));
if (requiredItemType.getGenre() != item.getGenre()) {
message.append(" is ");
message.append(Err.describeGenre(item.getGenre()));
} else {
message.append(" does not match. ");
if (th != null) {
Optional more = requiredItemType.explainMismatch(item, th);
//noinspection OptionalIsPresent
if (more.isPresent()) {
message.append(more.get());
}
}
}
return message.toString();
}
/**
* Construct a full error message, in terms of UTypes
*
* @param requiredItemType the item type required by the context of a particular expression
* @param suppliedItemType the item type inferred by static analysis of an expression
* @return a message of the form "Required item type of A is R; supplied value has item type S"
*/
public String composeErrorMessage(ItemType requiredItemType, UType suppliedItemType) {
return composeRequiredMessage(requiredItemType) +
"; supplied value has item type " +
suppliedItemType;
}
/**
* Save as a string, for use when serializing the expression tree
* @return a string representation of the object
*/
public String save() {
StringBuilder fsb = new StringBuilder(256);
fsb.append(kind + "|");
fsb.append(operand + "|");
fsb.append(errorCode.equals("XPTY0004") ? "" : errorCode);
fsb.append("|");
fsb.append(operation);
return fsb.toString();
}
/**
* Reconstruct from a saved string
* @param in the saved string representation of the RoleDiagnostic
* @return the RoleDiagnostic
*/
public static RoleDiagnostic reconstruct(String in) {
int v = in.indexOf('|');
int kind = Integer.parseInt(in.substring(0, v));
int w = in.indexOf('|', v+1);
int operand = Integer.parseInt(in.substring(v+1, w));
int x = in.indexOf('|', w+1);
String errorCode = in.substring(w+1, x);
String operation = in.substring(x+1);
RoleDiagnostic cd = new RoleDiagnostic(kind, operation, operand);
if (!errorCode.isEmpty()) {
cd.setErrorCode(errorCode);
}
return cd;
}
/**
* Get the ordinal representation of a number (used to identify which argument of a function
* is in error)
*
* @param n the cardinal number
* @return the ordinal representation
*/
public static String ordinal(int n) {
switch (n) {
case 1:
return "first";
case 2:
return "second";
case 3:
return "third";
default:
if (n >= 21) {
switch (n % 10) {
case 1:
return n + "st";
case 2:
return n + "nd";
case 3:
return n + "rd";
}
}
return n + "th";
}
}
}