[Patch, Fortran, OOP] PR 46971: [4.6 Regression] ICE on long class names

[Jerry DeLisle]

On 12/30/2010 01:28 PM, Janus Weil wrote:
> Hi Thomas,
>
>>> A stronger argument would be the lack of uniqueness, i.e. a hashed
>>> name colliding with a plain-text name, but I think this is practically
>>> impossible.
>>
>> I think we have had that discussion before, sort of :-)
>
> at least a similar one ...
>
>
>> Could you maybe insert a couple of leading underscores into the hashed
>> class name so that a user would have to do something really illegal
>> (i.e. make up a class name with two leading underscores) to get a
>> collision?
>
> I think it's easier to do the opposite: Make sure the plain-text
> string contains a character which cannot appear in the hash string
> (which is in hex: 0-9, A-F). Let's take the underscore (a single one
> is sufficient), since we already have that in most cases. I have
> modified the patch to make sure that it appears in *all* cases (cf.
> get_unique_type_string). There you go, the improbable is now
> impossible ;)
>
> Another small change I made in 'gfc_hash_value' is to remove the
> modulus. It only saved two digits in the mod file, but it increased
> the probability of a hash collision.
>
> Ok for trunk? (I'll do another regtest just to be on the safe side.)

Yes, OK.  and yes I have been following the thread and did review the patch and 
since i am in a later time zone, thought I would jump in here.

Jerry