bug#26644: [m4/libtool.m4] TCC and unsupported option '-fPIC'

[Marcel Raad]

Hi,

I'm building curl [1] with TCC (Tiny C compiler) on Linux. For every
compiled source file, I get:
tcc: warning: unsupported option '-fPIC'

What I do is
./configure --enable-warnings CC=tcc && make
which enables warnings about unsupported GCC options (-Wunsupported)
at build time, but not at configure time.

libtool.m4 adds -fPIC, but according to the TCC documentation [2], TCC
doesn't support PIC at all.

I'm using Ubuntu 16.04 with libtool 2.4.6 and TCC 0.9.26.

[1] https://github.com/curl/curl/
[2] http://bellard.org/tcc/tcc-doc.html#SEC17

Thanks,
Marcel