| Call_External and referenced symbol not found [message #30583] |
Tue, 07 May 2002 11:00  |
![Todd David halter[1] is currently offline](theme/default/images/xoffline.png.pagespeed.ic.XRkd1fkXye.png "Todd David halter[1] is currently offline")
Todd David halter[1]
Messages: 4
Registered: May 2002
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Junior Member |
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I am working on a Sun SPARC Ultra-2 with OS 5.7 and IDL 5.4.
I am using call_external to call an external C function. I have made my
so file and can call my test functions within the so file just fine. The
problem comes when I try to call a function from my so that is located in
a .a file.
example:
37 long
38 zinit (int argc, void *argv[])
39 {
40 IDL_STRING processName;
41
42 FILE *fp;
43
44 processName = *(IDL_STRING *)argv[0];
45
46 fp = fopen ("zlog.debug", "a");
47 fprintf (fp, "processName = %s\n", processName.s);
48 fclose (fp);
49
50 /* Set up connections to zeb */
51 usy_init (); /* located in libZeb.a */
52
53 return (TRUE);
54 } /* end zinit (...) */
This function works fine until I add line 51. When I add this line I get
the
error (in IDL):
ld.so.1: /apps/base/rsi/idl_5.4/bin/bin.solaris2.sparc64/idl: fatal:
relocation error: file ../../bin/zlog.so: symbol usy_init: referenced
symbol not found
Killed
My IDL term crashes and I have to log out of the system.
Do I need to make libZeb.a into a so file?
Any help would be greatly appreciated.
Thanks.
Todd Halter, todd*DOT*halter*AT*pnl*DOT*gov
Pacific Northwest National Laboratory
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| Re: Call_External and referenced symbol not found [message #30658 is a reply to message #30583] |
Mon, 13 May 2002 02:03  |
Nigel Wade
Messages: 286
Registered: March 1998
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Senior Member |
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Todd David halter wrote:
> I made a mistake in my initial post. The function that is giving me
> trouble is in libsocket.a. From my so file (zlog.so) I am calling the
> function usy_init () which is located is libsocket.a, which is located in
> /usr/lib. The way I am compiling it is:
>
> cc -g -G -K pic -xarch=v9 -I/apps/base/rsi/idl_5.4/external -c zlog.c -o
> obj/zlog.o
> cc -B static -G -K pic -xarch=v9 -L/usr/lib -lsocket -o zlog.so
> obj/zlog.o
^^^^^^^^
>
> The v9 tell it to create 64bit code not 32bit. I am still getting the
> same error. I will keep playing with it, but if anyone can see what I am
> doing wrong please let me know. Thanks.
>
> Todd
I think the problem is the order of the arguments to cc (and therefore to
ld).
The arguments to ld (which is used by cc to do the linking) are order
dependent. Libraries are scanned in the position in which they occur on the
command line, and they are scanned only once. At the time libsocket is
scanned, the externals in zlog.o are not undefined, so ld does not include
them in the resultant DSO. Try changing the order of the arguments to cc,
placing libraries *after* the objects.
--
-----------------------------------------------------------
Nigel Wade, System Administrator, Space Plasma Physics Group,
University of Leicester, Leicester, LE1 7RH, UK
E-mail : nmw@ion.le.ac.uk
Phone : +44 (0)116 2523568, Fax : +44 (0)116 2523555
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| Re: Call_External and referenced symbol not found [message #30699 is a reply to message #30583] |
Thu, 09 May 2002 07:41 |
Malcolm Walters
Messages: 8
Registered: October 2001
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Junior Member |
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"Todd David halter" <thalter@beta.tricity.wsu.edu> wrote in message
news:abbhks$21ov$1@murrow.it.wsu.edu...
> I do have the -lZeb and it still does not work. If you would post you
> long re: that would be great.
>
> Todd
Todd, I'm not 100% sure exactly what you are doing, I mainly work on Linux
but this should transfer ok.
What I have done before on several occasions is;
1) Start with an archive file. (libA.a)
2) Write functions calling this library (B.c) and compile using something of
the form
gcc -shared -o libB.so B.c -lA
3) Call the wrapper functions in libB from within IDL.
Note that all the functions you are going to call in 'libA.a' from IDL must
be referenced in 'B.c'. If you miss any out then the resulting shared object
does not contain the functions and they cannot be called. This can be done
in a dummy routine that you will never call if necessary. All call_externals
should call 'libB.so'.
If you have the source for libA then recompile it to give a shared object.
This way B.c only needs to make calls that actually do something.
Then if you wish to call functions in libA then you must call these directly
(call_external,'libA.so',...)
You will need to have both libraries on your 'LD_LIBRARY_PATH' environmental
variable.
Note that either of these should give you only one instance of each shared
library. If you have an archive do not try something like
gcc -shared -o libOpenB.so OpenB.c -lA
gcc -shared -o libCloseB.so CloseB.c -lA
if you need internal data within libA to be preseved between the open and
close calls.
Malcolm
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| Re: Call_External and referenced symbol not found [message #30719 is a reply to message #30583] |
Wed, 08 May 2002 02:01 |
Malcolm Walters
Messages: 8
Registered: October 2001
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Junior Member |
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"Todd David halter" <thalter@beta.tricity.wsu.edu> wrote in message
news:ab94o1$fhu3$1@murrow.it.wsu.edu...
> Do I need to make libZeb.a into a so file?
> Any help would be greatly appreciated.
> Thanks.
I was in the middle of a long response detailing archive vs. shared object
behaviour but I think this is straight forward.
When creating your shared object are you linking it against libZeb.a? If you
are not then try adding a '-lZeb' to your link step.
Otherwise I will post my longer explanation about shared objects.
Malcolm
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