How does each browser expose intermediary representation of JavaScript?

Question

Question:

I've heard people use the terms dynamic compilation and interpretation interchangeably. This isn't a question about semantics.

Obviously by the time the code hits the processor it is in some binary form.

How can I look at intermediate represenation?

For example, it is pretty easy to look at your C code in assembly by using compiler options.

Is there a similar way to do this with JavaScript? I'm not sure what the intermediary representation would be called but here are some general references.

Research

• Interpreter (Wikipedia)

• Dynamic Compilation (Wikipedia)

• Compilation (Wikipedia)

Clarification:

This question has nothing to do with minification.

• mindoftea: If I may ask, why do you want to find a way to do this?
• mindoftea: So, you mean optimization?
• pimvdb: For V8, you can run d8 --print_code or d8 --print_opt_code
• templatetypedef: There is no one standard, universally agreed-upon internal representation for JavaScript and each JS engine interprets or compiles JS in its own way. You are probably best off picking a nice JS engine like Rhino and checking the docs to see if it can do what you want it to do.
• Mark Schultheiss: @templatetypedef - that comment seems like an answer to me :)

Answer 1

If you build V8 yourself by compiling the d8 shell, you can run d8 --print_code or d8 --print_opt_code. You probably want to output this data into a file.

Answer 2

See if these slides from Vyacheslav Egorov's mö.js JSConf talk get you any closer to what you need.