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Thanks Craig, I'm trying to compile a very simple test with Visual Studio (2008), but I get the following errors: c:\program files\postgresql\8.3\include\server\pg_config_os.h(188) : error C2011: 'timezone' : 'struct' type redefinition c:\program files\postgresql\8.3\include\server\pg_config_os.h(188) : see declaration of 'timezone' c:\program files\postgresql\8.3\include\server\pg_config_os.h(197) : error C2011: 'itimerval' : 'struct' type redefinition c:\program files\postgresql\8.3\include\server\pg_config_os.h(197) : see declaration of 'itimerval' c:\program files\postgresql\8.3\include\server\c.h(97) : fatal error C1083: Cannot open include file: 'libintl.h': No such file or directory I must be doing something wrong - I don't even have a libintl.h on my drive... This is my .cpp file: #ifdef PG_MODULE_MAGIC PG_MODULE_MAGIC; #endif #define _USE_32BIT_TIME_T #include "postgres.h" #include <string.h> #include "fmgr.h" /* by value */ PG_FUNCTION_INFO_V1(add_one); Datum add_one(PG_FUNCTION_ARGS) { int32 arg = PG_GETARG_INT32(0); PG_RETURN_INT32(arg + 1); } If you can help, that would be wonderful. Thanks a lot, George. > Date: Tue, 10 Mar 2009 02:35:34 +0900 > From: craig@xxxxxxxxxxxxxxxxxxxxx > To: oakmang@xxxxxxxxxxx > CC: pgsql-general@xxxxxxxxxxxxxx > Subject: Re: C++ User-defined functions > > George Oakman wrote: > > > I am trying to write a user-defined function in C++. Most examples are give in plain C. I would be very grafeful for a sample program/code-snippet in C++. > > It's just like any other C/C++ code mixing. You must make sure that any > C-only headers are included within an `extern "C"' block, and declare > any functions that'll be accessed via dlopen() etc as 'extern "C"' too. > You may only use POD types, arrays of POD types, and structs of POD > types (with no methods) in calls to/from C code. > > In other words, all PostgreSQL must see is plain C code, but your > 'extern "C"' functions may call C++ methods and work with C++ objects > internally. > > There's lots more information about this on the Internet. Just look for > generic resources on calling C from C++ and vice versa. > > (I don't *think* there are any issues with libstdc++, though you'd > probably have to make sure that no other program linked into Pg brings > in a different version of libstdc++.) > > -- > Craig Ringer > > -- > Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-general Windows Live Hotmail just got better. Find out more! |
