Re: gcc/config/arch/arch.opt: Option mask gen problem

[Jim Wilson <jimw@sifive.com>]

On Mon, Jul 22, 2019 at 4:05 AM Maxim Blinov <maxim.blinov@embecosm.com> wrote:
> Is it possible, in the arch.opt file, to have GCC generate a bitmask
> relative to a user-defined variable without an associated name? To
> illustrate my problem, consider the following option file snippet:
> ...
> But, I don't want the user to be able to pass "-mbmi-zbb" or
> "-mno-bmi-zbb" on the command line:

If you don't want an option, why are you making changes to the
riscv.opt file?  This is specifically for supporting command line
options.

Adding a variable here does mean that it will automatically be saved
and restored, and I can see the advantage of doing that, even if it is
only indirectly tied to options.  You could add a variable here, and
then manually define the bitmasks yourself in riscv-opt.h or riscv.h.
Or you could just add the variable to the machine_function struct in
riscv.c, which will also automatically save and restore the variable.

Jim