Re: [SQL] g++ not working for postgresql extension languages?

Lonnie,

C++ uses "name mangling" to permit overloading of functions. Therefore
your function concat_text() ends up with a very different name. You can
probably get round this as follows:

#ifdef __cplusplus
extern "C" {
#endif
text *
concat_text(text *arg1, text *arg2);
#ifdef __cplusplus
}
#endif

This tells the C++ compiler that concat_text is a "C" name - so don't do
name mangling. This is a common technique for making C++ code callable
from C, although I haven't used it in the specific context you are
using.

Hope this helps,

Stephen Jackson
Home: Stephen(dot)Jackson(at)panting-deer(dot)org(dot)uk www.panting-deer.org.uk
Work: Stephen(dot)Jackson(at)looksystems(dot)co(dot)uk www.looksystems.co.uk

Lonnie Cumberland wrote:
>
> Hi All again,
>
> One more thing that I have tried.
>
> If I now do a similar thing as in my previous message with the "funcs.c" file,
> but this time with the "funcs.cc" file then I can get:
>

[snip]

>
> trdata=# select concat_text('a','b');
> ERROR: Can't find function concat_text in file /test/funcs.so
> trdata=#
> --------------------------------------------------------------------------
>

[snip]

>
> text *
> concat_text(text *arg1, text *arg2);
>

[snip]

> so now I do not understand why the "gcc" version works and the "g++" version
> does not?
>
> Just a side note in that I can easliy compile c++ the examples in the
> interfaces/libpq++ directory without any problems so that this is very strange
> to me.
>
> I really need the "g++" version to work correctly as well?
>
> Any ideas anyone?
>
> Cheers
> Lonnie
>