Re: Need help building & integrating library into target program

[stuarts@icpdd.neca.nec.com.au (Stuart Summerville)]

(More apologies for re-posts - seemingly posting to the mailing list ain't the
same as posting to the usenet newsgroup...)


>It would be best to show us how you're trying to link against the
>library; knowing your platform would also be helpful.
>--ag
>

Hi Arthur,

Given that I have mylib.a in the current directory, I issue the command:

gcc -static -g -o rw startup_lib.a

to produce the rw executable. Then, issuing the command:

ldd rw

tells me that this dynamically linked executable is dependent on mylib.o. I
presume that as its linked statically, there shouldn't be any lib dependence....

Tools used:
Solaris 2.5.1
gcc egcs-2.91.57 19980901 (egcs-1.1 release)
ld 2.8.1 (with BFD 2.8.1)

Also, mylib.a was created in the following manner:

gcc -MD -I../include -g -o init.o -c init.c
ar rv ../../../obj/mylib.a *.o

I've seen the same behaviour on two Sol251 boxes.

To contrast this, if I do the same thing on a Redhat Linux (5.2) box (gcc =
2.7.2.3, ld = 2.9.1 (with BFD 2.9.1.0.15)), it works fine. If statically linked,
ldd won't touch it (unlike the Solaris box, which still shows that erroneous
dependence) & it runs properly; if dynamically linked, ldd reports that libc and
ld-linux are linked but no mylib.a (or even mylib.o).

?

Some other questions:

1) does linking of libraries dynamically only affect files specified with the -l
switch to ld? Can a file specified as an ordinary object file to ld, be
dynamically linked in? eg. if I don't supply ld with the -static switch, will
archive files passed in the manner "ld -o myprog mylib.a ..." be statically
linked anyway?
2) Is there any use in my creating arcive/object files with the -shared switch
to ld? This seems to be a useful thing to do, but the ld manpage suggests its
not a common method anymore.

Thanks,

sTu.

_________________________________________________________________________
Stuart Summerville                         NEC Australia Pty. Ltd.
ph: (+61 3) 9264-3090                      Integrated Comm Products (R&D)
fax:(+61 3) 9264-3841                      649-655 Springvale Road
e-mail: stuarts@icpdd.neca.nec.com.au      Mulgrave, VIC 3170, AUSTRALIA  
________________________________________________________________________
Stuart Summerville                     NEC Australia Pty. Ltd.
ph: (+61 3) 9264-3090                  Integrated Comm Products (R&D)
fax:(+61 3) 9264-3841                  649-655 Springvale Road Mulgrave
stuarts@<nospam>icpdd.neca.nec.com.au  VIC 3170, AUSTRALIA