Re: [Tinycc-devel] linux/unix shared libraries?

[Olaf Dietrich]

grischka (2008-04-21T18:07:35+0200):
> Works for me. (on ubuntu 6.02)


That's good news - so what might go wrong here?
Did I use the appropriate compiler/linker options?

(Are you saying that you did exactly the same
things that I did, or that you were (somehow) able
to build a shared library?)

If I display the shared library dependencies of the files
compiled/linked with tcc; I get:

$ ldd libmylib.so 
        linux-gate.so.1 =>  (0xb7f01000)
        libc.so.6 => /lib/tls/i686/cmov/libc.so.6 (0xb7dc2000)
        /lib/ld-linux.so.2 (0x80000000)
$ ldd testlib
        linux-gate.so.1 =>  (0xb7fb4000)
        libmylib.so => /home/olaf/tcc_test/libmylib.so (0xb7fb0000)
        libc.so.6 => /lib/tls/i686/cmov/libc.so.6 (0xb7e75000)
        /lib/ld-linux.so.2 (0xb7fb5000)

which looks pretty similar to the results after
building with gcc.

However, with the additional -r or -d switch, the result is:

$ ldd -d -r libmylib.so 
/usr/bin/ldd: line 117: 21091 Segmentation fault      LD_TRACE_LOADED_OBJECTS=1 
LD_WARN=yes LD_BIND_NOW=yes LD_LIBRARY_VERSION=$verify_out LD_VERBOSE= "$@"
        linux-gate.so.1 =>  (0xb7f58000)
        libc.so.6 => /lib/tls/i686/cmov/libc.so.6 (0xb7e19000)
        /lib/ld-linux.so.2 (0x80000000)
$ ldd -d -r testlib
/usr/bin/ldd: line 117: 21096 Segmentation fault      LD_TRACE_LOADED_OBJECTS=1 
LD_WARN=yes LD_BIND_NOW=yes LD_LIBRARY_VERSION=$verify_out LD_VERBOSE= "$@"
        linux-gate.so.1 =>  (0xb7f1c000)
        libmylib.so => /home/olaf/tcc_test/libmylib.so (0xb7f18000)
        libc.so.6 => /lib/tls/i686/cmov/libc.so.6 (0xb7ddd000)
        /lib/ld-linux.so.2 (0xb7f1d000)

(again some "segmentation faults").

Any suggestions what to try?

(The system here is a Debian stable with
 "/lib/libc.so.6 -> libc-2.3.6.so".)


Olaf



> From: "Olaf Dietrich":
> > The simple question is: Is it or has it ever been possible to
> > compile shared libraries with tcc under linux/unix?
> > 
> > Here is a very simple test case:
> > 
> > 
> > $ cat mylib.c
> > 
> > int func(void)
> > {
> >         return 12345;
> > }
> > 
> > 
> > $ cat testlib.c
> > 
> > #include <stdio.h>
> > 
> > extern int func(void);
> > 
> > int main(void) {
> >         printf("%d\n", func());
> >         return 0;
> > }
> > 
> > 
> > Using gcc, I can simply compile these files and 
> > obtain a working shared library:
> > 
> > $ export LD_LIBRARY_PATH=`pwd`
> > $ gcc -fPIC -shared mylib.c -o libmylib.so
> > $ gcc testlib.c -L. -lmylib -o testlib
> > $ ./testlib 
> > 12345
> > 
> > How can I do the same thing with tcc? I tried:
> > 
> > $ export LD_LIBRARY_PATH=`pwd`
> > $ tcc -r -shared mylib.c -o libmylib.so
> > $ tcc testlib.c -L. -lmylib -o testlib
> > $ ./testlib 
> > Segmentation fault