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