[Rcpp-devel] Shared library error after update

[Kevin Ushey]

The bug is simply that the constructor is left declared, but
undefined, for const_SlotProxy objects. In SlotProxy.h, we have:

class const_SlotProxy : public GenericProxy<const_SlotProxy> {
    public:
        const_SlotProxy( const CLASS& v, const std::string& name) ;
        const_SlotProxy& operator=(const const_SlotProxy& rhs) ;

        template <typename T> operator T() const {
          return as<T>( get() );
        }
        inline operator SEXP() const {
            return get() ;
        }

    private:
        const CLASS& parent;
        SEXP slot_name ;

        SEXP get() const {
            return R_do_slot( parent, slot_name ) ;
        }
    } ;

Note that the const_SlotProxy constructor is declared, but never
defined. I think this was missed in the proxy class cleanup, where a
lot of proxy 'meat' was inlined for compatibility with Solaris.
Fortunately it's trivial to fix and I'll push something to the GitHub
repo in a second.

Cheers,
Kevin

On Mon, Mar 3, 2014 at 11:21 AM, Kevin Ushey <kevinushey at gmail.com> wrote:
> Hi Simon,
>
> I can replicate this, and also fix this, if I change 'const Rcpp::S4&
> classS4' to 'Rcpp::S4 classS4'. (That is, assuming a simple example
> where I try to compile that class and construct an object using
> sourceCpp).
>
> Since Rcpp classes are just proxy objects, you don't have to worry too
> much about passing Rcpp objects by value, since you are essentially
> just copying pointers.
>
> As for what the actual regression is -- that will take some more investigation.
>
> Try changing that around and let me know if things work.
>
> Cheers,
> Kevin
>
> On Mon, Mar 3, 2014 at 10:59 AM, Simon Zehnder <szehnder at uni-bonn.de> wrote:
>> Hi Kevin,
>>
>> the github repo is a good idea, though I have some dependencies on other C++ libraries that have to be installed first and that makes it unfavourable.
>>
>> However, I figured out where the source of the error seems to be: It is a header file of a C++ class that can be constructed from an Rcpp::S4 object. It looks like this:
>>
>> #ifndef FINMIXDATA_H
>> #define FINMIXDATA_H
>>
>> #include <RcppArmadillo.h>
>> #include <string>
>>
>> class FinmixData {
>>         public:
>>                 arma::mat y;
>>                 arma::ivec S;
>>                 arma::vec expos;
>>                 arma::vec T;
>>
>>                 std::string dataType;
>>                 unsigned int N;
>>                 unsigned int r;
>>
>>                 /* constructor */
>>                 FinmixData (const Rcpp::S4& classS4) :
>>                   y(Rcpp::as<arma::mat>((SEXP) classS4.slot("y"))),
>>                  S(Rcpp::as<arma::ivec>((SEXP) classS4.slot("S"))),
>>                  expos(Rcpp::as<arma::vec>((SEXP) classS4.slot("exp"))),
>>                  T(Rcpp::as<arma::vec>((SEXP) classS4.slot("T"))),
>>                  dataType(Rcpp::as<std::string>((SEXP) classS4.slot("type"))),
>>                  N(Rcpp::as<unsigned int>((SEXP) classS4.slot("N"))),
>>                  r(Rcpp::as<unsigned int>((SEXP) classS4.slot("r"))) {}
>>                ~FinmixData () {}
>> };
>> #endif
>>
>> This worked before the update. It seems to me that I have to change the initialisation list .... I work on it. Any suggestions are welcome!
>>
>> Best
>>
>> Simon
>>
>>
>> On 03 Mar 2014, at 17:53, Kevin Ushey <kevinushey at gmail.com> wrote:
>>
>>> Do you have a GitHub repository or some other means of sharing your
>>> package, so we can try testing it?
>>>
>>> On Mon, Mar 3, 2014 at 6:12 AM, Dirk Eddelbuettel <edd at debian.org> wrote:
>>>>
>>>> On 3 March 2014 at 14:38, Simon Zehnder wrote:
>>>> | Though I couldn't detect NEWS relevant for my package. I have rebuilt my package several times now and the error remains. I remember that there was once some news about Rcpp now being header only (also the Rcpp.package.skeleton function does not include a Makevars file in the src folder). Does that mean I delete the line
>>>> |
>>>> | PKG_LIBS = '$(R_HOME)/bin/Rscript -e "Rcpp:::LdFlags()"'
>>>> |
>>>> | from my Makevars file?
>>>>
>>>> Yes you may.
>>>>
>>>> | Is it obligatory?
>>>>
>>>> No.
>>>>
>>>> If it were mandatory to remove it we would have said so. It is now a null-op
>>>>
>>>>   edd at max:~$ Rscript -e 'Rcpp:::LdFlags()'
>>>>   edd at max:~$
>>>>
>>>> under the current version of Rcpp, and works as before under previous version
>>>> ensuring continuity.
>>>>
>>>> Please construct a minimally reproducible example.  Based on your two emails
>>>> there is no further help I can give you.
>>>>
>>>> Dirk
>>>>
>>>> --
>>>> Dirk Eddelbuettel | edd at debian.org | http://dirk.eddelbuettel.com
>>>> _______________________________________________
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>>>> Rcpp-devel at lists.r-forge.r-project.org
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>>