Is there any method to find out a static library is compiled with -fPIC flag

Question

I have a bunch of static libraries in my hand, which all have two versions -- 32bit and 64bit. When I use these static libraries to compile into a shared library, weird things happened: 1. I use 64bit static libraries to compile a 64bit shared library, everything works well; 2. I use 32bit static libraries to compile a 32bit shared library, ld tells me that the [text section is not shareable].

So, I guess that 32bit static libraries don't use -fPIC flag, but my colleague tells me he dit add the flag. But I still suspect that, so is there a way to find out whether the static library do add the -fPIC flag. PS: I know use readelf or objdump may get some clues, but is there a better way?

Pithecanthropus

possible duplicate of How can I tell, with something like objdump, if an object file has been built with -fPIC? – Gravettian

Answer 1

I believe, if you are using linux, you can check out the output of file

file myLib.so
file myLib.a

The output should inform you if the library was compiled with -fPIC

Zibeline

well, I tried. I build test.o and test_pic.o by myself, but the output is all: ELF 64-bit LSB relocatable, x86-64, version 1 (SYSV), not stripped – Pithecanthropus

Do you run file for the objects, or the library? – Zibeline

I run for the objects file. If run for the library, libtest.a for example, the output will only tell : 'archive file'. – Pithecanthropus

Hmm... Try running for libtest.so. It should say more than that. libtest.a is indeed an archive of object files, so that's why file reports it as such. – Zibeline

Well, what I need is identify a static library. So, this may don't work. – Pithecanthropus

Oh, okay,, Sorry this didn't work, best of luck finding your answer :) – Zibeline