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"undefined reference" error when compiling extension functions

From: "Mark Miller" <mark(at)maxpreps(dot)com>
To: <pgsql-hackers-win32(at)postgresql(dot)org>
Subject: "undefined reference" error when compiling extension functions
Date: 2005-04-25 20:36:41
Message-ID: 20050425203935.86E1B54A46@svr1.postgresql.org (view raw or flat)
Thread:
Lists: pgsql-hackers-win32
I am trying to figure out how to write extension functions and I am getting
"undefined reference" errors when I compile on the lines which call "malloc"
and "pfree". How can I get the compiler to see the functions so I can
compile successfully?

 

I installed PostgreSQL on XP Pro using the windows installer, then I
installed the includes (which are not part of the windows install) by
running the following commands:

 

configure --without-zlib --includedir=/c/progra~1/postgresql/8.0/include
--with-includes=/c/progra~1/postgresql/8.0/include/port/win32/*

make -C src/include install

 

 

Here's the output from make when I try to compile:

 

$ make makefile filesize.dll

make: Nothing to be done for `makefile'.

gcc -g -I c:/Progra~1/PostgreSQL/8.0/include -I
c:/Progra~1/PostgreSQL/8.0/include/server -I
c:/Progra~1/PostgreSQL/8.0/include/server/port/win32 -I
c:/Progra~1/PostgreSQL/8.0/lib -fpic -c filesize.c

cc1.exe: warning: -fpic ignored for target (all code is position
independent)

gcc -g -I c:/Progra~1/PostgreSQL/8.0/include -I
c:/Progra~1/PostgreSQL/8.0/include/server -I
c:/Progra~1/PostgreSQL/8.0/include/server/port/win32 -I
c:/Progra~1/PostgreSQL/8.0/lib -shared -o filesize.dll filesize.o

filesize.o(.text+0x1a): In function `filesize':

C:/msys/1.0/home/mark/dev/filesize.c:9: undefined reference to
`pg_detoast_datum'

filesize.o(.text+0x3d):C:/msys/1.0/home/mark/dev/filesize.c:11: undefined
reference to `_imp__CurrentMemoryContext'

filesize.o(.text+0x44):C:/msys/1.0/home/mark/dev/filesize.c:11: undefined
reference to `MemoryContextAlloc'

filesize.o(.text+0x9b):C:/msys/1.0/home/mark/dev/filesize.c:19: undefined
reference to `pfree'

filesize.o(.text+0xb1):C:/msys/1.0/home/mark/dev/filesize.c:25: undefined
reference to `pfree'

make: *** [filesize.dll] Error 1

 

 

Here's the source I'm trying to compile (taken from PostgreSQL ch 6 by
Douglas and Douglas):

 

#include "postgres.h"

#include "fmgr.h"

#include <sys/stat.h>

 

PG_FUNCTION_INFO_V1(filesize);

 

Datum filesize(PG_FUNCTION_ARGS)

{

            text * fileNameText = PG_GETARG_TEXT_P(0);

            size_t fileNameLen = VARSIZE( fileNameText ) - VARHDRSZ;

            char * fileName = (char *)palloc( fileNameLen + 1 );

            struct stat statBuf;

 

            memcpy( fileName, VARDATA( fileNameText), fileNameLen );

            fileName[fileNameLen] = '\0';

 

            if( stat(fileName, &statBuf) == 0 && S_ISREG(statBuf.st_mode) )

            {

                        pfree( fileName );

 

                        PG_RETURN_INT32((int32)statBuf.st_size);

            }

            else

            {

                        pfree( fileName );

 

                        PG_RETURN_NULL();

            }

}

 

Here's the makefile, from the same example but modified to include the
needed include directories and to output ".dll" file instead of ".so".

 

# File name: makefile

SERVER_INCLUDES += -I $(shell pg_config --includedir)

SERVER_INCLUDES += -I $(shell pg_config --includedir-server)

SERVER_INCLUDES += -I $(shell pg_config --includedir-server)/port/win32

SERVER_INCLUDES += -I $(shell pg_config --libdir)

 

CFLAGS += -g $(SERVER_INCLUDES)

 

.SUFFIXES:      .dll

 

.c.dll:

            $(CC) $(CFLAGS) -fpic -c $<

            $(CC) $(CFLAGS) -shared -o $@ $(basename $<).o

 

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Next:From: Andrew DunstanDate: 2005-04-25 21:04:49
Subject: Re: "undefined reference" error when compiling
Previous:From: John DeSoiDate: 2005-04-25 17:42:05
Subject: Re: Custom Install

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