Thank you for your answer.
I did see that part of the code, but still I cannot understand, because the
TARGET_OPTION_OVERRIDE is called before the finalization.
So why doing a test on flag_pic before finalization?
Thank you
Best regards
Enrico Bragante
Il gio 26 set 2024, 23:43 Jakub Jelinek <ja...@redhat.com> ha scritto:
> On Thu, Sep 26, 2024 at 11:20:15PM +0200, Enrico via Gcc wrote:
> > I am trying to understand how 'flag_pic' works.
> > It is used extensively in TARGET_OPTION_OVERRIDE functions in the form
> 'if
> > (flag_pic) ... '.
> > The flags fPic and fpic have a default value of -1, so as far as I
> > understand, if the two flags are not set in the command line, all 'if
> > (flag_pic)' will be true because of the default value -1 (since I can see
> > that flag_pic is a define to global_options.x_flag_pic)
> >
> > It doesn't look correct to me, but this test is used so many times that I
> > am sure I am missing something.
>
> Yes, you are missing gcc/opts.cc (finish_options)
> if (!opts->x_flag_opts_finished)
> {
> /* We initialize opts->x_flag_pie to -1 so that targets can set a
> default value. */
> if (opts->x_flag_pie == -1)
> {
> /* We initialize opts->x_flag_pic to -1 so that we can tell if
> -fpic, -fPIC, -fno-pic or -fno-PIC is used. */
> if (opts->x_flag_pic == -1)
> opts->x_flag_pie = (opts->x_flag_hardened
> ? /*-fPIE*/ 2 : DEFAULT_FLAG_PIE);
> else
> opts->x_flag_pie = 0;
> }
> /* If -fPIE or -fpie is used, turn on PIC. */
> if (opts->x_flag_pie)
> opts->x_flag_pic = opts->x_flag_pie;
> else if (opts->x_flag_pic == -1)
> opts->x_flag_pic = 0;
> if (opts->x_flag_pic && !opts->x_flag_pie)
> opts->x_flag_shlib = 1;
> opts->x_flag_opts_finished = true;
> }
> The -1 value just means the state of this option hasn't been finalized yet.
>
> Jakub
>
>
