Re: Static libraries with fPIC on x86

[Andrew Haley <aph at redhat dot com>]

john blair wrote:
> I have built openssl-0.9.8k and am trying to link libcrypto.a statically with my project. 
> For example, consider the following:
> #include <openssl/des.h>
> void foo(void) {
>             DES_encrypt3(NULL, NULL, NULL, NULL);
>             AES_encrypt(NULL, NULL);
>
> }
>
> $ gcc -fPIC -o libfoo.so -shared foo.c /usr/lib/libcrypto.a
> $ eu-findtextrel libfoo.so
> the file containing the function 'DES_encrypt3' is not compiled with -fpic/-fPIC
> the file containing the function 'DES_decrypt3' is not compiled with -fpic/-fPIC
> the file containing the function 'DES_ncbc_encrypt' is not compiled with -fpic/-fPIC
> the file containing the function 'DES_ede3_cbc_encrypt' is not compiled with -fpic/-fPIC
>
> This does not happen on 64bit system and eu-findtextrel reports on text relocations. I think this is the default behavior on x86 systems.
>
> Can someone point me to why building static libs on 32 bit system with fPIC is a bad idea?

It slows things down a bit because 32 bit x86 doesn't have PC-relative addressing.

> Also, if I want to build the static lib with fPIC, how do I go about it? All the .o files are built with fPIC

Then I don't know why it hasn't worked.  It always works for me.

Andrew.