R devel - Dec 2017 - winbuilder warning message wrt function pointers

I've recently updated the coxme package, which calls internal routines from
the bdsmatrix
package.? (It is in fact mentioned as an example of this in the Extensions
manual.)
The call connections are a blocks like this, one for each of the 9 called C
routines.

void bdsmatrix_prod4(int nrow,??? int nblock,?? int *bsize,
 ??????????????????? double *bmat, double *rmat,
 ??????????????????? int nfrail,?? double *y) {
 ??? static void (*fun)() = NULL;
 ??? if (fun==NULL)
 ??? fun = (void (*)) R_GetCCallable("bdsmatrix",
"bdsmatrix_prod4");
 ??? fun(nrow, nblock, bsize, bmat, rmat, nfrail, y);
 ??? }

..

The winbuilder run is flagging all of these with

bdsmatrix_stub.h:22:6: warning: ISO C forbids assignment between function
pointer and
'void *' [-Wpedantic]
 ? fun = (void (*)) R_GetCCallable("bdsmatrix",
"bdsmatrix_prod4");

Ignore?? Or should these lines have been written in a different way?

Terry T.

Try changing
  static void (*fun)() = NULL;
to
  DL_FUNC fun = NULL;

Bill Dunlap
TIBCO Software
wdunlap tibco.com

On Fri, Dec 29, 2017 at 5:14 AM, Therneau, Terry M., Ph.D. <
therneau at mayo.edu> wrote:
> I've recently updated the coxme package, which calls internal routines
> from the bdsmatrix package.  (It is in fact mentioned as an example of this
> in the Extensions manual.)
> The call connections are a blocks like this, one for each of the 9 called
> C routines.
>
> void bdsmatrix_prod4(int nrow,    int nblock,   int *bsize,
>                     double *bmat, double *rmat,
>                     int nfrail,   double *y) {
>     static void (*fun)() = NULL;
>     if (fun==NULL)
>     fun = (void (*)) R_GetCCallable("bdsmatrix",
"bdsmatrix_prod4");
>     fun(nrow, nblock, bsize, bmat, rmat, nfrail, y);
>     }
>
> ..
>
> The winbuilder run is flagging all of these with
>
> bdsmatrix_stub.h:22:6: warning: ISO C forbids assignment between function
> pointer and 'void *' [-Wpedantic]
>   fun = (void (*)) R_GetCCallable("bdsmatrix",
"bdsmatrix_prod4");
>
> Ignore?  Or should these lines have been written in a different way?
>
> Terry T.
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
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And remove the cast on the return value of R_GETCCallable.  And check
that your function is found before using it.

#include <R.h>
#include <Rinternals.h>
#include <R_ext/Rdynload.h>

void bdsmatrix_prod4(int nrow,    int nblock,   int *bsize,
                    double *bmat, double *rmat,
                    int nfrail,   double *y) {
    DL_FUNC fun = NULL;
    if (fun==NULL) {
        fun = R_GetCCallable("bdsmatrix",
"bdsmatrix_prod4");
    }
    if (fun==NULL) {
        Rf_error("Cannot find C function 'bdsmatrix_prod4' in
library
'bdsmatrix.{so,dll}'");
    }
    fun(nrow, nblock, bsize, bmat, rmat, nfrail, y);
    }




Bill Dunlap
TIBCO Software
wdunlap tibco.com

On Fri, Dec 29, 2017 at 8:48 AM, William Dunlap <wdunlap at tibco.com>
wrote:
> Try changing
>   static void (*fun)() = NULL;
> to
>   DL_FUNC fun = NULL;
>
> Bill Dunlap
> TIBCO Software
> wdunlap tibco.com
>
> On Fri, Dec 29, 2017 at 5:14 AM, Therneau, Terry M., Ph.D. <
> therneau at mayo.edu> wrote:
>
>> I've recently updated the coxme package, which calls internal
routines
>> from the bdsmatrix package.  (It is in fact mentioned as an example of
this
>> in the Extensions manual.)
>> The call connections are a blocks like this, one for each of the 9
called
>> C routines.
>>
>> void bdsmatrix_prod4(int nrow,    int nblock,   int *bsize,
>>                     double *bmat, double *rmat,
>>                     int nfrail,   double *y) {
>>     static void (*fun)() = NULL;
>>     if (fun==NULL)
>>     fun = (void (*)) R_GetCCallable("bdsmatrix",
"bdsmatrix_prod4");
>>     fun(nrow, nblock, bsize, bmat, rmat, nfrail, y);
>>     }
>>
>> ..
>>
>> The winbuilder run is flagging all of these with
>>
>> bdsmatrix_stub.h:22:6: warning: ISO C forbids assignment between
function
>> pointer and 'void *' [-Wpedantic]
>>   fun = (void (*)) R_GetCCallable("bdsmatrix",
"bdsmatrix_prod4");
>>
>> Ignore?  Or should these lines have been written in a different way?
>>
>> Terry T.
>>
>> ______________________________________________
>> R-devel at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-devel
>
>
>
	[[alternative HTML version deleted]]

You can legally cast a function pointer to another function pointer, where
the signatures differ.  (It is not legal to cast between data and function
pointers.)
I would make typedefs for the various signatures, as the casting syntax is
more
readable then.

Bill Dunlap
TIBCO Software
wdunlap tibco.com

On Fri, Dec 29, 2017 at 10:13 AM, Therneau, Terry M., Ph.D. <
therneau at mayo.edu> wrote:
> Bill,
>   That's a very nice solution.  It is both cleaner looking and
preferable
> to track R's .h files.
> However, some of my routines don't have void * as the return type (two
are
> int *), and Rdynload has
>
>    typedef void * (*DL_FUNC)();
>
> Will this untruth mess anything up?
>
> Terry T.
>
> On 12/29/2017 10:52 AM, William Dunlap wrote:
>
> And remove the cast on the return value of R_GETCCallable.  And check
> that your function is found before using it.
>
> #include <R.h>
> #include <Rinternals.h>
> #include <R_ext/Rdynload.h>
>
> void bdsmatrix_prod4(int nrow,    int nblock,   int *bsize,
>                     double *bmat, double *rmat,
>                     int nfrail,   double *y) {
>     DL_FUNC fun = NULL;
>     if (fun==NULL) {
>         fun = R_GetCCallable("bdsmatrix",
"bdsmatrix_prod4");
>     }
>     if (fun==NULL) {
>         Rf_error("Cannot find C function 'bdsmatrix_prod4' in
library
> 'bdsmatrix.{so,dll}'");
>     }
>     fun(nrow, nblock, bsize, bmat, rmat, nfrail, y);
>     }
>
>
>
>
> Bill Dunlap
> TIBCO Software
> wdunlap tibco.com
>
> On Fri, Dec 29, 2017 at 8:48 AM, William Dunlap <wdunlap at
tibco.com> wrote:
>
>> Try changing
>>   static void (*fun)() = NULL;
>> to
>>   DL_FUNC fun = NULL;
>>
>> Bill Dunlap
>> TIBCO Software
>> wdunlap tibco.com
>>
>> On Fri, Dec 29, 2017 at 5:14 AM, Therneau, Terry M., Ph.D. <
>> therneau at mayo.edu> wrote:
>>
>>> I've recently updated the coxme package, which calls internal
routines
>>> from the bdsmatrix package.  (It is in fact mentioned as an example
of this
>>> in the Extensions manual.)
>>> The call connections are a blocks like this, one for each of the 9
>>> called C routines.
>>>
>>> void bdsmatrix_prod4(int nrow,    int nblock,   int *bsize,
>>>                     double *bmat, double *rmat,
>>>                     int nfrail,   double *y) {
>>>     static void (*fun)() = NULL;
>>>     if (fun==NULL)
>>>     fun = (void (*)) R_GetCCallable("bdsmatrix",
"bdsmatrix_prod4");
>>>     fun(nrow, nblock, bsize, bmat, rmat, nfrail, y);
>>>     }
>>>
>>> ..
>>>
>>> The winbuilder run is flagging all of these with
>>>
>>> bdsmatrix_stub.h:22:6: warning: ISO C forbids assignment between
>>> function pointer and 'void *' [-Wpedantic]
>>>   fun = (void (*)) R_GetCCallable("bdsmatrix",
"bdsmatrix_prod4");
>>>
>>> Ignore?  Or should these lines have been written in a different
way?
>>>
>>> Terry T.
>>>
>>> ______________________________________________
>>> R-devel at r-project.org mailing list
>>> https://stat.ethz.ch/mailman/listinfo/r-devel
>>
>>
>>
>
>
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