Re: Need help building & integrating library into target program

["Stuart Summerville (Deimus)" <stus@deimus.com.au>]

(Sorry for the repost - resent to maintain thread)

>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.

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Stuart Summerville
Home: stus@deimus.com.au
Work: stuart.summerville@icpdd.neca.nec.com.au
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