/** Provides a configurable query for printing AST nodes */

private import unified

/**

* The query can extend this class to control which nodes are printed.

*/

class PrintAstConfiguration extends string {

PrintAstConfiguration() { this = "PrintAstConfiguration" }

/**

* Holds if the given node should be printed.

*/

predicate shouldPrintNode(AstNode n) { not n instanceof TriviaToken }

/**

* Holds if the given edge should be printed.

*/

predicate shouldPrintAstEdge(AstNode parent, string edgeName, AstNode child) {

exists(string name, int i |

child = PrintAst::getChild(parent, name, i) and

(if i = -1 then edgeName = name else edgeName = name + "(" + i + ")")

)

}

}

private predicate shouldPrintNode(AstNode n) {

any(PrintAstConfiguration config).shouldPrintNode(n)

}

private predicate shouldPrintAstEdge(AstNode parent, string edgeName, AstNode child) {

any(PrintAstConfiguration config).shouldPrintAstEdge(parent, edgeName, child) and

shouldPrintNode(parent) and

shouldPrintNode(child)

}

/**

* Get an alias for the predicate `name` to use for ordering purposes, to control where

* in the list of children it should appear.

*/

private string reorderName1(string name) { name = "getModifier" and result = "00_getModifier" }

bindingset[name]

private string reorderName(string name) {

result = reorderName1(name)

or

not exists(reorderName1(name)) and

result = name

}

class PrintAstNode extends AstNode {

final int getOrder() {

this =

rank[result](AstNode parent, AstNode child, string name, int i |

child = PrintAst::getChild(parent, name, i)

|

child order by reorderName(name), i

)

}

final string getProperty(string key) {

key = "semmle.label" and

result = this.toString()

or

key = "semmle.order" and result = this.getOrder().toString()

}

}

/**

* Holds if `node` belongs to the output tree, and its property `key` has the

* given `value`.

*/

query predicate nodes(PrintAstNode node, string key, string value) {

shouldPrintNode(node) and

value = node.getProperty(key)

}

/**

* Holds if `target` is a child of `source` in the AST, and property `key` of

* the edge has the given `value`.

*/

query predicate edges(PrintAstNode source, PrintAstNode target, string key, string value) {

key = "semmle.label" and

shouldPrintAstEdge(source, value, target)

or

key = "semmle.order" and

shouldPrintAstEdge(source, _, target) and

value = target.getProperty("semmle.order")

}

/**

* Holds if property `key` of the graph has the given `value`.

*/

query predicate graphProperties(string key, string value) {

key = "semmle.graphKind" and value = "tree"

}