On Tue, 23 Oct 2018 at 17:14, Segher Boessenkool <seg...@kernel.crashing.org> wrote: > > On Tue, Oct 23, 2018 at 02:58:21PM +0100, Richard Earnshaw (lists) wrote: > > On 15/10/2018 11:10, Christophe Lyon wrote: > > > Do you mean to also make -mfdpic non-existent/rejected when GCC is not > > > configured > > > for arm-uclinuxfdpiceabi? > > > > Ideally doesn't exist, so that it doesn't show up in things like --help > > when it doesn't work. > > > > > How to achieve that? > > > > Good question, I'm not sure, off hand. It might be possible to make the > > config machinery add additional opt files, but it's not something I've > > tried. You might want to try adding an additional opt file to > > extra_options for fdpic targets. > > That should work yes. You could look at how 476.opt is added for powerpc, > it is a comparable situation. >
Thanks, I got it to work. Now back to Richard's original question: > I think this needs to be resolved. Either -mfdpic works everywhere, or > the option should only be available when configured for -mfdpic. It's not that -mfdpic does not work everywhere, rather it is not sufficient to use it alone: it should be used along with fpic/fPIC/fpie/fPIE depending on the use case. In practice I don't know if we want to be able to use -mfdpic with a arm-linux-gnueabi toolchain, or if we are ok to have to use two different toolchains when we want to make tests/compare code generation in both cases. The 1st option means I should improve the documentation patch. For the 2nd one, I have patches in progress (which also imply reworking the doc since the option would not also be available) Christophe > > Segher