On 20 Mar 2007, at 00:50, Duncan Murdoch wrote:
> On 3/19/2007 8:41 PM, Ernest Turro wrote:
>> On 20 Mar 2007, at 00:18, Duncan Murdoch wrote:
>>> On 3/19/2007 7:41 PM, Ernest Turro wrote:
>>>> On 19 Mar 2007, at 21:32, Duncan Murdoch wrote:
>>>>> On 3/19/2007 5:23 PM, Ernest Turro wrote:
>>>>>> Hi,
>>>>>> I'm trying to register my native routines using
>>>>>> R_registerRoutines (...). I can compile the code, but the
>>>>>> loader cannot resolve the symbol:
>>>>>> undefined symbol:
>>>>>> _Z18R_registerRoutinesP8_DllInfoPK12R_CMethodDefPK15R_CallMethodD
>>>>>> ef S3 _S6 _
>>>>>> $ nm bgx.Rcheck/bgx/libs/bgx.so | grep R_registerRoutines
>>>>>> U
>>>>>> _Z18R_registerRoutinesP8_DllInfoPK12R_CMethodDefPK15R_CallMethodD
>>>>>> ef S3 _S6 _
>>>>>> Why does it have this funny name? If I look at libR.so, I get
>>>>>> an ordinary symbol name:
>>>>> That looks like C++ name mangling. Are you wrapping your
>>>>> declarations in
>>>>>
>>>>> extern "C" { }
>>>>>
>>>>> ?
>>>> Yeah, the routine is literally just:
>>>> extern "C"
>>>> void R_init_bgx(DllInfo *info) {
>>>> R_registerRoutines(info, cMethods,NULL,NULL,NULL);
>>>> }
>>>> with cMethods declared outside as a static const R_CMethodDef.
>>> I'm no C++ expert, but that looks like it declares R_init_bgx to
>>> be a "C" routine, but not R_registerRoutines (which is what the
>>> error was about). Its declaration is in Rdynload.h:
>>>
>>> #ifdef __cplusplus
>>> extern "C" {
>>> #endif
>>> int R_registerRoutines(DllInfo *info, const R_CMethodDef * const
>>> croutines,
>>> const R_CallMethodDef * const callRoutines,
>>> const R_FortranMethodDef * const fortranRoutines,
>>> const R_ExternalMethodDef * const
>>> externalRoutines);
>>>
>>> Rboolean R_useDynamicSymbols(DllInfo *info, Rboolean value);
>>> #ifdef __cplusplus
>>> }
>>> #endif
>>>
>>> so maybe your compiler doesn't define __cplusplus, or you didn't
>>> include R_ext/Rdynload.h?
Duncan, you hit the nail on the head. Thanks so much.
If you download R-2.4.1.tar.gz from CRAN you will find that the
extern "C" is missing in Rdynload.h! I added it to my copy and my
code compiles now. I wonder why it's missing. Has this been fixed in
cvs?
Thanks,
Ernest
PS. you don't need the braces after extern "C"
>> Thanks for the reply.
>> __cplusplus is defined and I do #include <R_ext/Rdynload.h>
>> (after all, it does compile)...
>> I've tried this on two different machines, so it's not a problem
>> specific to my setup either... ):
>
> Here I'm just guessing: you don't wrap the whole function in
> extern "C", you just put extern "C" ahead of its header. That's not
> the usual way it's done, but I don't know C++ well enough to know
> if it matters. Nevertheless, I'd try
>
> extern "C" {
> void R_init_bgx(DllInfo *info) {
> R_registerRoutines(info, cMethods,NULL,NULL,NULL);
> }
> }
>
> just to see if it helps.
>
> Duncan Murdoch
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