Front page | perl.perl5.porters |
Postings from May 2013
On 7 May 2013 11:09, demerphq <demerphq@gmail.com> wrote:
> On 7 May 2013 11:07, Nicholas Clark <nick@ccl4.org> wrote:
>> On Tue, May 07, 2013 at 11:02:08AM +0200, demerphq wrote:
>>> On 7 May 2013 10:55, Nicholas Clark <nick@ccl4.org> wrote:
>>
>>> >> Can anybody replicate this?
>>> >
>>> > Util.xs: In function 'void XS_Hash__Util_hash_traversal_mask(CV*)':
>>> > Util.xs:94: error: invalid conversion from 'const HV*' to 'HV*'
>>> > Util.xs:94: error: initializing argument 1 of 'void Perl_hv_rand_set(HV*, U32)'
>>> > make[1]: *** [Util.o] Error 1
>>> > make[1]: Leaving directory `/home/nick/Perl/perl/ext/Hash-Util'
>>> > Unsuccessful make(ext/Hash-Util): code=512 at make_ext.pl line 490.
>>> > make: *** [lib/auto/Hash/Util/Util.so] Error 2
>>> >
>>> > It's passing a const HV* pointer to a function taking HV*
>>> >
>>> > if (SvROK(rhv) && SvTYPE(SvRV(rhv))==SVt_PVHV && !SvMAGICAL(SvRV(rhv))) {
>>> > const HV * const hv = (const HV *) SvRV(rhv);
>>> > if (items>1) {
>>> > hv_rand_set(hv, SvUV(ST(1)));
>>> >
>>> >
>>> > I don't know if the right fix is to change that line from 'const HV * const hv'
>>> > or to change Perl_hv_rand_set to take a const HV * parameter.
>>>
>>> Thanks a lot, I eventually figured that out from one of Georges smoke
>>> reports which made it easier to see.
>>>
>>> I was just doing a local build/test on the former. I see no reason not
>>> to use the latter, do you perchance know which is "better"?
>>
>> I *think* that
>>
>> a) having const pointers is better than non-const pointers
>> but only if the 'const' is telling the truth
>> (because it gives the compiler more opportunities at the call site)
>> b) In this case one can't make Perl_hv_rand_set() take a const HV *,
>> because it calls Perl_hv_iterinit(), and *that* potentially modifies
>> the (top level) HV struct.
>>
>> So that leaves only one possible answer :-)
>> The one you're already doing.
>>
>> (And yes, this means that I've thought a bit further since my previous e-mail)
>
> Your mail arrived just as I was typing:
>
> "
> If I change Perl_hv_rand_set() to take a const HV* then I get further
> moans from hv_auxinit().
>
> Also, *all* of the other hash functions take a non-const HV parameter,
> and it feels weird making this new one the odd man out. Maybe we
> should look into that for next release cycle?
> "
>
> So I think we are on the same page here. :-)
>
> Thanks for the support Nicholas!
Dennis changed the Jenkins config to not do parallel builds and I can
now see what I did wrong. Fixing.
Yves
--
perl -Mre=debug -e "/just|another|perl|hacker/"
Thread Previous
|
Thread Next