Thread

1. compiling extension functions? (fwd)

   Tripp Lilley <tlilley@perspex.com> — 1998-02-11T19:41:22Z

   I posted this to questions a few days back but got no response. Can anyone
   here help me with this? I know it should be straightforward, and that I'm
   missing something obvious, but precisely *what* I'm missing is unknown to
   me.
   
   Thanks!
   
   - t.
   
   -----------------------------------------------------------------------
      Tripp Lilley, Perspex Imageworks, Inc. (tripp.lilley@perspex.com)
   -----------------------------------------------------------------------
         "Give me a fast computer, for I intend to go in harm's way"
                         - updating John Paul Jones
   
   ---------- Forwarded message ----------
   Date: Mon, 9 Feb 1998 12:42:48 -0500 (EST)
   From: Tripp Lilley <tlilley@perspex.com>
   To: pgsql-questions@postgresql.org
   Subject: compiling extension functions?
   
   I'm trying to compile and use a 'C' extension function for PG 6.2.1 under
   Red Hat Linux 4.2 (stock distribution). I am executing the following
   commands to compile my shared library and install my function, but I get
   "Unable to resolve symbol" when I try to execute the function.
   
   > gcc -fpic -shared salmon.c -o salmon.so -L/usr/lib -lpq 
   -I/usr/include/postgres
   > touch salmon.sql
   > psql -d nim_0_01 -f salmon.sql
   drop function salmon (int4);
   DROP
   
   create function
                   salmon (int4)
           returns
                   char16
           as
                   '/home/tlilley/projects/perspex/scratch/nim/salmon.so'
           language
                   'c';
   CREATE
   EOF
   
   
   > psql -d nim_0_01
   
   nim_0_01=> select salmon( 42 );
   WARN:Load of file /home/tlilley/projects/perspex/scratch/nim/salmon.so
   failed: Unable to resolve symbol
   nim_0_01=> 
   
   
   And here's the source for my function:
   
   #include <postgres.h>
   #include <utils/palloc.h>
   
   
   char16 * salmon (int4 value)
   {
     char16 * buffer = (char16 *) palloc( sizeof( char16 ) );
   
   
     memset( (void *) buffer, 0, sizeof( char16 ) );
     (void) strncpy( buffer, "hello", 16 );
     return( buffer );
   }
   
   
   Any help (especially 'working' compile command-lines) would be great!
   
   Thanks...
   
   - t.
   
   -----------------------------------------------------------------------
      Tripp Lilley, Perspex Imageworks, Inc. (tripp.lilley@perspex.com)
   -----------------------------------------------------------------------
         "Give me a fast computer, for I intend to go in harm's way"
                         - updating John Paul Jones
   
   
   
   

2. Re: [HACKERS] compiling extension functions? (fwd)

   Thomas Lockhart <lockhart@alumni.caltech.edu> — 1998-02-12T02:31:28Z

   > I'm trying to compile and use a 'C' extension function for PG 6.2.1 under
   > Red Hat Linux 4.2 (stock distribution). I am executing the following
   > commands to compile my shared library and install my function, but I get
   > "Unable to resolve symbol" when I try to execute the function.
   >
   > > gcc -fpic -shared salmon.c -o salmon.so -L/usr/lib -lpq
   > -I/usr/include/postgres
   > > touch salmon.sql
   > > psql -d nim_0_01 -f salmon.sql
   > drop function salmon (int4);
   > DROP
   >
   > create function
   >                 salmon (int4)
   >         returns
   >                 char16
   >         as
   >                 '/home/tlilley/projects/perspex/scratch/nim/salmon.so'
   >         language
   >                 'c';
   > CREATE
   > EOF
   >
   > > psql -d nim_0_01
   >
   > nim_0_01=> select salmon( 42 );
   > WARN:Load of file /home/tlilley/projects/perspex/scratch/nim/salmon.so
   > failed: Unable to resolve symbol
   > nim_0_01=>
   >
   > And here's the source for my function:
   >
   > #include <postgres.h>
   > #include <utils/palloc.h>
   >
   > char16 * salmon (int4 value)
   > {
   >   char16 * buffer = (char16 *) palloc( sizeof( char16 ) );
   >
   >   memset( (void *) buffer, 0, sizeof( char16 ) );
   >   (void) strncpy( buffer, "hello", 16 );
   >   return( buffer );
   > }
   >
   > Any help (especially 'working' compile command-lines) would be great!
   
   Look in contrib/int8/ for code and Makefile which were developed on RH Linux
   4.2. ld may not be finding the libraries it needs. You may need to set
   LD_LIBRARY (or something like that, don't remember the name exactly) and/or
   modify /etc/ld.so.conf then run ldconfig to get the load library database
   pointing at the Postgres libraries.
   
   Good luck.
   
                                                                  - Tom