linker wrapper

[Rainer Schuetze]

Walter Bright wrote:
> Rainer Schuetze wrote:
>>
>> Walter, is optlink able to deal with this 3rd representation in all 
>> places, so we can get rid of those other two encodings?
> 
> The way long symbols on Windows are dealt with:
> 
> 1. if they fit, they fit
> 2. try using the extended length method
> 3. try compressing the string
> 4. use a hash for the string
> 
> 1..3 are reversible, 4 is not.
> 

Doing it always in this order would be fine, because 2. is bound to 
never fail.

Checking the source (but probably missing some places), I see that

- obj_namestring uses 1,2
- obj_mangle uses 1,3,4,2 with a length limit of 128
- Library::FillDict uses 1,2, but might crash due to limited buffer size 
(for symbols longer than 468 characters - is this a limitation of the 
library format?)
- cv_namestring uses 1,2

So I tried compiling ddmd skipping 3 and 4 in obj_mangle, but that 
caused crashes for symbols longer than IDMAX (=900). Increasing that 
limit (max length was >5600) caused a crash in optlink. But as far as I 
can see, limiting the usage of 3 and 4 to symbols longer than IDMAX 
seems to work (though I have not done any more testing). Actually, this 
version is already in the code, but deliberately replaced by the limit 
of 128 characters, so there might be a reason...

Rainer