[Rcpp-devel] package .onLoad multiple modules

[Romain Francois]

Le 30/05/11 01:56, baptiste auguie a écrit :
> Thanks, that is helpful. I think I have nailed down the problem.
>
> I defined a wrapper at R level that used a C++ function from a module
> named "cd",
>
> circular_dichroism_spectrum<- function( ... ){
>
>   [...] # some argument processing
>
>    res<- cd$circular_dichroism_spectrum(...) # calling the C++ function
>
>   return(res)
> }
>
> Now, with loadRcppModules(), no "cd" module is created, as far as I
> can tell, and invoking circular_dichroism_spectrum() is calling the
> C++ function directly; a segfault results because some of the
> arguments differ between the C++ function and its R wrapper.
>
> I see two options:
>
> - choose a different name for the R and C++ functions
>
> - manage some kind of namespace masking the C++ function from the
> top-level, like cd$ did before. Is there a way to do this in the
> loadRcppModules() approach?

Not currently. functions and classes are directly exposed in the 
namespace. I guess we could add an argument to control that.

In the meantime, I'd use your first option.

> Best regards,
>
> baptiste
>
>
> On 30 May 2011 11:11, Dirk Eddelbuettel<edd at debian.org>  wrote:
>>
>> On 30 May 2011 at 10:29, baptiste auguie wrote:
>> | Hi,
>> |
>> | On 30 May 2011 04:28, Dirk Eddelbuettel<edd at debian.org>  wrote:
>> |>
>> |>  On 29 May 2011 at 18:56, baptiste auguie wrote:
>> |>  | Dear list,
>> |>  |
>> |>  | [Disclaimer: I am not very familiar with Rcpp/C++, and probably
>> |>  | haven't followed all the relevant discussions on this list.]
>> |>  |
>> |>  | I'm trying to tidy up two packages on r-forge [*] before submitting
>> |>  | them to CRAN. In "cda/zzz.r", I have the following code,
>> |>  |
>> |>  | NAMESPACE<- environment()
>> |>  | cda<- new( "Module" )
>> |>  | cdatests<- new( "Module" )
>> |>  | cd<- new( "Module" )
>> |>  | linear<- new( "Module" )
>> |>  | array<- new( "Module" )
>> |>  |
>> |>  | .onLoad<- function(libname, pkgname){
>> |>  |   unlockBinding( "cda" , NAMESPACE )
>> |>  |   unlockBinding( "cdatests" , NAMESPACE )
>> |>  |   unlockBinding( "cd" , NAMESPACE )
>> |>  |   unlockBinding( "linear" , NAMESPACE )
>> |>  |   assign( "cda", Module( "cda" ), NAMESPACE )
>> |>  |   assign( "cdatests", Module( "cdatests" ), NAMESPACE )
>> |>  |   assign( "cd", Module( "cd" ), NAMESPACE )
>> |>  |   assign( "linear", Module( "linear" ), NAMESPACE )
>> |>  |   lockBinding( "cda", NAMESPACE )
>> |>  |   lockBinding( "cdatests", NAMESPACE )
>> |>  |   lockBinding( "cd", NAMESPACE )
>> |>  |   lockBinding( "linear", NAMESPACE )
>> |>  |
>> |>  |   unlockBinding( "array" , NAMESPACE )
>> |>  |   assign( "array", Module( "array" ), NAMESPACE )
>> |>  |   lockBinding( "array", NAMESPACE )
>> |>  |
>> |>  | }
>> |>  |
>> |>  | It seems to work, but is there something I can/should do to make this
>> |>  | a wee cleaner?
>> |>
>> |>  Have another look at the Rcpp-modules vignette, and/or the third set of
>> |>  slides ("Advanced Rcpp") from our class in April -- you no longer need the
>> |>  unlockBinding / lockBinding business as Romain internalized that. The
>> |>  skeleton-generated packages now just do this in zzz.R:
>> |>
>> |>    .onLoad<- function(pkgname, libname){
>> |>        loadRcppModules()
>> |>    }
>> |>
>> |>  using a 'RcppModules: cda, cdatests, cd, linear, array' declaration in
>> |>  DESCRIPTION.
>> |
>> | Strange, this does not seem to work for me.
>> |
>> | If I use the following zzz.r, (with RcppModules listed in DESCRIPTION)
>> |
>> | .onLoad<- function(libname, pkgname){
>> |    loadRcppModules()
>> | }
>> |
>> | I get a segfault whenever I use a c++ function,
>> |
>> |  *** caught segfault ***
>> | address 0x0, cause 'memory not mapped'
>> |
>> | Traceback:
>> |  1: .External(list(name = "InternalFunction_invoke", address =
>> |<pointer: 0x101407f30>,     dll = list(name = "Rcpp", path =
>> | "/Library/Frameworks/R.framework/Versions/2.13/Resources/library/Rcpp/libs/x86_64/Rcpp.so",
>> |         dynamicLookup = TRUE, handle =<pointer: 0x101441030>,
>> | info =<pointer: 0x1002b3ed0>), numParameters = -1L),<pointer:
>> | 0x103011050>, ...)
>> |  2: circular_dichroism_spectrum(clust, gold, n = 1.33, N = 36, progress = FALSE)
>> |  3: onecluster()
>> |
>> | Is there another step I'm missing?
>>
>> My first instinct is to check the unitTest, so look at what is different in
>> test run from
>>
>>    inst/unitTests/runit.Module.client.package.R
>>
>> using
>>
>>    inst/unitTests/testRcppModule/
>>
>> That should still work on your platform and you should be able to go from there.
>>
>> Dirk
>>
>> --
>> Gauss once played himself in a zero-sum game and won $50.
>>                       -- #11 at http://www.gaussfacts.com
>>
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Romain Francois
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