analyses

analyses

Basic data flow analyses framework based on esprima

Installation

$ npm install analyses

Dependencies

analyses depends on a globally available Map, which can either be provided by running with --harmony or by preloading a shim before using the library. analyses itself explicitly does not depend on a shim itself, to be more forward compatible and to give you more choice.

Since the collections, specifically Set in --harmony do not support any method to iterate over them, analyses provides a minimal analyses.Set shim with some useful set operations. This will change once native --harmony Sets are actually useful.

Usage

var cfg = esgraph(esprima.parse('…'));
var output = analyses(cfg, function (input, list) {
	this; // the cfg node
	input; // the input set
	list; // the worklist `.push()` nodes to it.
	return new analyses.Set(); // either return a new output Set
	// or return an output Set and `enqueue: false` so the worklist algorithm does
	// not check and enqueue successors itself.
	return {output: new analyses.Set(), enqueue: false}
}, {
	// direction:
	// forward or backward; defaults to forward
	direction: 'forward',
	// custom merge function:
	// typically union or intersect; defaults to union
	// merge function takes an array of inputs
	// `analyses.merge()` wraps a function which takes a pair `a, b` of inputs
	merge: analyses.merge(analyses.Set.union),
	// custom equals function:
	// this is used to determine if the output of a node still changes and to
	// not enqueue any more successors and stop the iteration; defaults to
	// Set.equals
	equals: analyses.Set.equals
});
// the output is a `Map` from CFG nodes to a result set of type `analyses.Set`
output.get(cfg[0]).values()

License

LGPLv3