[Newcompiler] What compiler is used when debugger needs line information

[Klaus D. Witzel]

Hi Marcus,

this is good to know and I personally see no reason for suporting two  
compilers (one of which with limited capabilities) in the same image.

But since a mix of methods could happen to the uniformed I'd appreciate a  
short note "caution when debugging mixed methods" in the readme.

Cheers
Klaus

On Tue, 29 May 2007 16:02:37 +0200, Marcus Denker wrote:

>
> On 29.05.2007, at 14:06, Klaus D. Witzel wrote:
>
>> List,
>>
>> in an offline email thread (with Stef, Roel, Damien and Math) about
>> optimizations which could be done by Smalltalk compiler, we
>> mentioned the
>> debugger needs information which is not in the bytecodes of a method.
>>
>> Imagine a method X was compiled with the new compiler and then the
>> preference is reset for using the old compiler. Now when X is
>> debugged,
>> the debugger compiles X's source code for obtaining source code
>> positions
>> (line information).
>>
>> It is quite possible this information no longer matches the method
>> (both
>> compilers can produce quite different bytecodes).
>>
>> How's that handled now?
>>
>
> It is just not handled right now. I do not know if we really need to
> have a solution
> for this: The idea is to replace the old compiler, not have an
> environment where
> both can be used together.
>
> We could add a property to the methods compiled either with the old
> or with the new
> compiler, and then switch to the right decompiler. But that would
> cost some space
> (property for all these methods) for not beeing really used... when
> would a complete
> mix of both methods happen? Now that we develop it, yes. So if we see
> that it really
> annoys us, we could add this. If not, we don't need to, as the goal
> is to not have any
> system with mixed methods in the future.
>
> 	Marcus