/**

* Provides classes and predicates for working with XML files and their content.

*/

import semmle.files.FileSystem

private class TXmlLocatable =

@xmldtd or @xmlelement or @xmlattribute or @xmlnamespace or @xmlcomment or @xmlcharacters;

/** An XML element that has a location. */

class XmlLocatable extends @xmllocatable, TXmlLocatable {

/** Gets the source location for this element. */

Location getLocation() { xmllocations(this, result) }

/**

* Holds if this element is at the specified location.

* The location spans column `startcolumn` of line `startline` to

* column `endcolumn` of line `endline` in file `filepath`.

* For more information, see

* [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).

*/

predicate hasLocationInfo(

string filepath, int startline, int startcolumn, int endline, int endcolumn

) {

exists(File f, Location l | l = this.getLocation() |

locations_default(l, f, startline, startcolumn, endline, endcolumn) and

filepath = f.getAbsolutePath()

)

}

/** Gets a textual representation of this element. */

string toString() { none() } // overridden in subclasses

}

/**

* An `XmlParent` is either an `XmlElement` or an `XmlFile`,

* both of which can contain other elements.

*/

class XmlParent extends @xmlparent {

XmlParent() {

// explicitly restrict `this` to be either an `XmlElement` or an `XmlFile`;

// the type `@xmlparent` currently also includes non-XML files

this instanceof @xmlelement or xmlEncoding(this, _)

}

/**

* Gets a printable representation of this XML parent.

* (Intended to be overridden in subclasses.)

*/

string getName() { none() } // overridden in subclasses

/** Gets the file to which this XML parent belongs. */

XmlFile getFile() { result = this or xmlElements(this, _, _, _, result) }

/** Gets the child element at a specified index of this XML parent. */

XmlElement getChild(int index) { xmlElements(result, _, this, index, _) }

/** Gets a child element of this XML parent. */

XmlElement getAChild() { xmlElements(result, _, this, _, _) }

/** Gets a child element of this XML parent with the given `name`. */

XmlElement getAChild(string name) { xmlElements(result, _, this, _, _) and result.hasName(name) }

/** Gets a comment that is a child of this XML parent. */

XmlComment getAComment() { xmlComments(result, _, this, _) }

/** Gets a character sequence that is a child of this XML parent. */

XmlCharacters getACharactersSet() { xmlChars(result, _, this, _, _, _) }

/** Gets the depth in the tree. (Overridden in XmlElement.) */

int getDepth() { result = 0 }

/** Gets the number of child XML elements of this XML parent. */

int getNumberOfChildren() { result = count(XmlElement e | xmlElements(e, _, this, _, _)) }

/** Gets the number of places in the body of this XML parent where text occurs. */

int getNumberOfCharacterSets() { result = count(int pos | xmlChars(_, _, this, pos, _, _)) }

/**

* Gets the result of appending all the character sequences of this XML parent from

* left to right, separated by a space.

*/

string allCharactersString() {

result =

concat(string chars, int pos | xmlChars(_, chars, this, pos, _, _) | chars, " " order by pos)

}

/** Gets the text value contained in this XML parent. */

string getTextValue() { result = this.allCharactersString() }

/** Gets a printable representation of this XML parent. */

string toString() { result = this.getName() }

}

/** An XML file. */

class XmlFile extends XmlParent, File {

XmlFile() { xmlEncoding(this, _) }

/** Gets a printable representation of this XML file. */

override string toString() { result = this.getName() }

/** Gets the name of this XML file. */

override string getName() { result = File.super.getAbsolutePath() }

/** Gets the encoding of this XML file. */

string getEncoding() { xmlEncoding(this, result) }

/** Gets the XML file itself. */

override XmlFile getFile() { result = this }

/** Gets a top-most element in an XML file. */

XmlElement getARootElement() { result = this.getAChild() }

/** Gets a DTD associated with this XML file. */

XmlDtd getADtd() { xmlDTDs(result, _, _, _, this) }

}

/**

* An XML document type definition (DTD).

*

* Example:

*

* ```

* <!ELEMENT person (firstName, lastName?)>

* <!ELEMENT firstName (#PCDATA)>

* <!ELEMENT lastName (#PCDATA)>

* ```

*/

class XmlDtd extends XmlLocatable, @xmldtd {

/** Gets the name of the root element of this DTD. */

string getRoot() { xmlDTDs(this, result, _, _, _) }

/** Gets the public ID of this DTD. */

string getPublicId() { xmlDTDs(this, _, result, _, _) }

/** Gets the system ID of this DTD. */

string getSystemId() { xmlDTDs(this, _, _, result, _) }

/** Holds if this DTD is public. */

predicate isPublic() { not xmlDTDs(this, _, "", _, _) }

/** Gets the parent of this DTD. */

XmlParent getParent() { xmlDTDs(this, _, _, _, result) }

override string toString() {

this.isPublic() and

result = this.getRoot() + " PUBLIC '" + this.getPublicId() + "' '" + this.getSystemId() + "'"

or

not this.isPublic() and

result = this.getRoot() + " SYSTEM '" + this.getSystemId() + "'"

}

}

/**

* An XML element in an XML file.

*

* Example:

*

* ```

* <manifest xmlns:android="http://schemas.android.com/apk/res/android"

* package="com.example.exampleapp" android:versionCode="1">

* </manifest>

* ```

*/

class XmlElement extends @xmlelement, XmlParent, XmlLocatable {

/** Holds if this XML element has the given `name`. */

predicate hasName(string name) { name = this.getName() }

/** Gets the name of this XML element. */

override string getName() { xmlElements(this, result, _, _, _) }

/** Gets the XML file in which this XML element occurs. */

override XmlFile getFile() { xmlElements(this, _, _, _, result) }

/** Gets the parent of this XML element. */

XmlParent getParent() { xmlElements(this, _, result, _, _) }

/** Gets the index of this XML element among its parent's children. */

int getIndex() { xmlElements(this, _, _, result, _) }

/** Holds if this XML element has a namespace. */

predicate hasNamespace() { xmlHasNs(this, _, _) }

/** Gets the namespace of this XML element, if any. */

XmlNamespace getNamespace() { xmlHasNs(this, result, _) }

/** Gets the index of this XML element among its parent's children. */

int getElementPositionIndex() { xmlElements(this, _, _, result, _) }

/** Gets the depth of this element within the XML file tree structure. */

override int getDepth() { result = this.getParent().getDepth() + 1 }

/** Gets an XML attribute of this XML element. */

XmlAttribute getAnAttribute() { result.getElement() = this }

/** Gets the attribute with the specified `name`, if any. */

XmlAttribute getAttribute(string name) { result.getElement() = this and result.getName() = name }

/** Holds if this XML element has an attribute with the specified `name`. */

predicate hasAttribute(string name) { exists(this.getAttribute(name)) }

/** Gets the value of the attribute with the specified `name`, if any. */

string getAttributeValue(string name) { result = this.getAttribute(name).getValue() }

/** Gets a printable representation of this XML element. */

override string toString() { result = this.getName() }

}

/**

* An attribute that occurs inside an XML element.

*

* Examples:

*

* ```

* package="com.example.exampleapp"

* android:versionCode="1"

* ```

*/

class XmlAttribute extends @xmlattribute, XmlLocatable {

/** Gets the name of this attribute. */

string getName() { xmlAttrs(this, _, result, _, _, _) }

/** Gets the XML element to which this attribute belongs. */

XmlElement getElement() { xmlAttrs(this, result, _, _, _, _) }

/** Holds if this attribute has a namespace. */

predicate hasNamespace() { xmlHasNs(this, _, _) }

/** Gets the namespace of this attribute, if any. */

XmlNamespace getNamespace() { xmlHasNs(this, result, _) }

/** Gets the value of this attribute. */

string getValue() { xmlAttrs(this, _, _, result, _, _) }

/** Gets a printable representation of this XML attribute. */

override string toString() { result = this.getName() + "=" + this.getValue() }

}

/**

* A namespace used in an XML file.

*

* Example:

*

* ```

* xmlns:android="http://schemas.android.com/apk/res/android"

* ```

*/

class XmlNamespace extends XmlLocatable, @xmlnamespace {

/** Gets the prefix of this namespace. */

string getPrefix() { xmlNs(this, result, _, _) }

/** Gets the URI of this namespace. */

string getUri() { xmlNs(this, _, result, _) }

/** Holds if this namespace has no prefix. */

predicate isDefault() { this.getPrefix() = "" }

override string toString() {

this.isDefault() and result = this.getUri()

or

not this.isDefault() and result = this.getPrefix() + ":" + this.getUri()

}

}

/**

* A comment in an XML file.

*

* Example:

*

* ```

* <!-- This is a comment. -->

* ```

*/

class XmlComment extends @xmlcomment, XmlLocatable {

/** Gets the text content of this XML comment. */

string getText() { xmlComments(this, result, _, _) }

/** Gets the parent of this XML comment. */

XmlParent getParent() { xmlComments(this, _, result, _) }

/** Gets a printable representation of this XML comment. */

override string toString() { result = this.getText() }

}

/**

* A sequence of characters that occurs between opening and

* closing tags of an XML element, excluding other elements.

*

* Example:

*

* ```

* <content>This is a sequence of characters.</content>

* ```

*/

class XmlCharacters extends @xmlcharacters, XmlLocatable {

/** Gets the content of this character sequence. */

string getCharacters() { xmlChars(this, result, _, _, _, _) }

/** Gets the parent of this character sequence. */

XmlParent getParent() { xmlChars(this, _, result, _, _, _) }

/** Holds if this character sequence is CDATA. */

predicate isCDATA() { xmlChars(this, _, _, _, 1, _) }

/** Gets a printable representation of this XML character sequence. */

override string toString() { result = this.getCharacters() }

}