How to traverse the AST generated by spidermonkey (Javascript file)

Question

I am very very new to Spidermonkey Parser and I have two questions. The first one is to have a good documentation (for beginners) about how to generate the AST of a Javascript file with spidermonkeyParser. And the second one is to know how to traverse the AST. My goal is to use the information in the AST to do some static analysis of the JS files (Type analysis, String analysis).

Thank you

Answer 1

The AST of Spidermonkey is exposed as Javascript objects. That means you should write a small Javascript script, use that script to read and parse the actual Javascript source file your want to parse and obtain the AST as Javascript objects.

This feature is available in the standalone SpiderMonkey shell (probably not in the version that comes with Firefox). You need to download the full Spidermonkey source and build it using the bundled python scripts. A Shell will be built along with your standalone Spidermonkey Javascript engine. This shell is just a small console program accepting user commands. The shell can read and execute standalone Javascript scripts. In particular, those Javascript scripts executed by this Shell have access to an extra global object called Reflect which has a method called parse(). The Shell also support extra file I/O functions which is the way you read in the target Javascript source you want to parse.

The description of the full AST is here:

https://developer.mozilla.org/en-US/docs/SpiderMonkey/Parser_API