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Otustelija
June 14th, 2009, 10:56 AM
I'm trying to link a C program with libblas. I've installed libblas-dev. This works:

gcc -lblas test1.c

However, I want to link statically. This fails

gcc -static -lblas test1.c
with an undefined reference to e.g. cblas_ddot. Linking the .a file directly works:

gcc test1.c /usr/lib/libblas.a

However, I don't want to rely on having it in the same location elsewhere. What am I doing wrong?

stroyan
June 14th, 2009, 03:44 PM
The problem is just a matter of link order.
When you link with -static, you need to carefully order archive libraries.
Code that uses a symbol must appear before the library that provides it.
You need to move "-lblas" so it appears after "test1.c".


gcc -static test1.c -lblas


That is different from what you are accustomed to with shared libraries
The linker just pulls in each shared library as a whole, so backward references work.

There are actually linker directives that will designate an unordered group of files.
But it can be much slower for large groups of files compared to sorting the library files.


gcc -static -Wl,--start-group -lblas test1.c -Wl,--end-group

Otustelija
June 14th, 2009, 03:52 PM
Thanks, just what I was looking for!