Re: "undefined reference" error when compiling

[Andrew Dunstan <andrew(at)dunslane(dot)net>]

Well, you picked a difficult target to learn on :-)

If you look in pgxs.mk you will see some clues.  You might need to set 
something to point to the installed lib directory (Maybe SHLIB_LINK ?). 
some value like -L/c/progra~1/postgresql/8.0/lib

And if you are coming from Windows build experience and think all this 
has rough edges, you're right, it does.

cheers

andrew

Mark Miller wrote:

> You're right, I could just install it there. That's the easiest way around
> it. But I WOULD like to know why it's mapping to the wrong directory and how
> to work around it. It would be better if I could install it where ever I
> like. I'm doing this all as a learning experince. Since I have no experience
> with any of these technologies (C, postgresql, gcc, makefiles), I just want
> to figure out how to do it right.
>
> Thanks,
> Mark
>
> -----Original Message-----
> From: Andrew Dunstan [mailto:andrew(at)dunslane(dot)net] 
> Sent: Monday, April 25, 2005 3:15 PM
> To: mark(at)maxpreps(dot)com
> Subject: Re: [pgsql-hackers-win32] "undefined reference" error when
> compiling extension functions
>
> Install instead to
>
> C:\MSYS\1.0\local\pgsql - under MSys that will map to /usr/local/pgsql
>
> Personally, if I were building extensions I would have built/installed pg
> from scratch, rather than using the installer.
>
> cheers
>
> andrew
>
>
> Mark Miller wrote:
>
>  
>
> > Thanks, that simplifies things.
> >
> > But I ran into the following problem:
> >
> > $ make
> > dlltool --export-all --output-def filesize.def filesize.o
> > dllwrap -o filesize.dll --def filesize.def filesize.o
> > c:/Progra~1/PostgreSQL/8.0/lib/pgxs/src/makefiles/../../src/utils/dllinit.o
> > -L/usr/local/pgsql/bin -lpostgres
> > c:\MinGW\bin\..\lib\gcc-lib\mingw32\3.2.3\..\..\..\..\mingw32\bin\ld.exe:
> > cannot find -lpostgres
> > c:\MinGW\bin\dllwrap.exe: c:\MinGW\bin\gcc exited with status 1
> > make: *** [filesize.dll] Error 1
> >
> >
> > Here's the makefile (located in /home/usr/dev (windows path is:
> > C:\MSYS\1.0\home\mark\dev)  ***:
> >
> >
> > MODULES = filesize
> >
> > PGXS := $(shell pg_config --pgxs)
> > include $(PGXS)
> >
> > *** ( postgresql is installed in C:\Progra~1\postgresql\8.0\)
> >
> > It looks like "-L/usr/local/pgsql/bin -lpostgres" is looking in the wrong
> > directory. I reinstalled making sure I used the --prefix parameter for
> > configure, but it's still looking in the wrong place. How do I point it to
> > the right "bin" directory?.
> >
> > Again, I did a windows install followed by using MinGW and MSYS to install
> > the headers needed for development. (The reason for doing separate installs
> > was so I could install PostgreSQL as a service and make sure the proper
> > accounts were set up).
> >
> > Thanks again for your help,
> > Mark
> >
> >
> > -----Original Message-----
> > From: Andrew Dunstan [mailto:andrew(at)dunslane(dot)net] 
> > Sent: Monday, April 25, 2005 2:05 PM
> > To: mark(at)maxpreps(dot)com
> > Cc: pgsql-hackers-win32(at)postgresql(dot)org
> > Subject: Re: [pgsql-hackers-win32] "undefined reference" error when
> > compiling extension functions
> >
> >
> > You might find using the pgxs setup, new in 8.0, useful. See 
> > http://www.postgresql.org/docs/current/static/xfunc-c.html#XFUNC-C-PGXS
> >
> > cheers
> >
> > andrew
> >
> > Mark Miller wrote:
> >
> >
> >
> >    
> >
> > > 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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