Re: JSD: Stepping by line

Adam Peller wrote:
> +1  In particular, I was concerned about the relatively complex logic that every
> debugger implementation has to go through to achieve stepping out/over/into --
> presumably the same logic in each implementation.  The lazy programmer in me
> wanted to just push this down a level in the stack to the JSD, but I gather the
> JSD was kept intentionally light?  But would moving this down the stack (perhaps
> into SpiderMonkey itself?) make the stepping logic any simpler or the code more
> solid?  For example, would you be able to make use of internal states for stack
> frame changes rather than compare line numbers, etc.?  Forgive my ignorance
> here, I really don't know much about JSD or SpiderMonkey.

I don't believe pushing the stepping logic down will improve its 
reliability, as SpiderMonkey only operates on the compiled instructions, 
anything that wants to use lines will still need that PC -> line 
conversion and comparison.

Pushing the line check over to the native code side of XPConnect will 
give a speed-up, although it's unclear by how much. Maybe if I feel good 
tonight, I'll try some things and see what happens.

-- 
James Ross <[email protected]>
ChatZilla Developer