Reading http://perldoc.perl.org/perlxs.html#The-NO_INIT-Keyword again, I see I have misread
When I read that link it seems to me that the current PDL code is totally misusing the NO_INIT keyword.
Looks to me that the variable 'pos' is simply a variable that has a value assigned to it - which, one suspects, is (by itself) insufficient to make it an "output" variable at all.
Also, it seems to me that any initializations using NO_INIT need to go after CODE
No, it needs to go *before* CODE. (Perhaps that's what you meant.) With both 2.2210 and 3.03, when I put PDL_Long * pos = NO_INIT; in the CODE section I get an error such as:
Core.xs:673: error: `NO_INIT' undeclared (first use in this function)
Cheers,
Rob
Update: This has now reached the point where I'm thinking I should probably present the function in its entirety. So here it is as it currently appears in Core.xs (which is autogenerated from Core.xs.PL):
SV *
at_c(x,position)
pdl* x
PDL_Long * pos = NO_INIT
CODE:
int npos, ipos;
double result;
pdl_make_physvaffine( x );
pos = pdl_packdims( ST(1), &npos);
if (pos == NULL || npos < x->ndims)
croak("Invalid position");
/* allow additional trailing indices
* which must be all zero, i.e. a
* [3,1,5] piddle is treated as an [3,1,5,1,1,1,....]
* infinite dim piddle
*/
for (ipos=x->ndims; ipos<npos; ipos++)
if (pos[ipos] != 0)
croak("Invalid position");
result=pdl_at(PDL_REPRP(x), x->datatype, pos, x->dims,
(PDL_VAFFOK(x) ? x->vafftrans->incs : x->dimincs), PDL_REPROFF
+S(x),
x->ndims);
SET_RETVAL_NV(x) ;
OUTPUT:
RETVAL
To reiterate - that will work fine as is with 2.2210, but only works with 3.03 if there is a typemap entry for 'PDL_Long *'. (With 3.03 it doesn't seem to matter what that typemap entry specifies - as long as there is one.)
If I don't amend the typemap, then to make that Core.xs work with both 2.2210 and 3.03 I have to remove the PDL_Long * pos = NO_INIT and begin the CODE section with a PDL_Long * pos; declaration. | [reply]
[d/l]
[select] |
When I read that link it seems to me that the current PDL code is totally misusing the NO_INIT keyword.
Yes, this.
No, it needs to go *before* CODE. (Perhaps that's what you meant.)
No, I meant after CODE, without NO_INIT , like you did in your tests, PDL_Long * pos;
| [reply]
[d/l] |