On Wed, 16 Mar 2022 14:45:33 -0400
Marek Polacek <[email protected]> wrote:
Hi Marek,
> Let's avoid -f-foo; use -ffoo instead, like the rest of GCC.
Sure. I hadn't noticed the distinction.
> > In cobol/lang.opt, I have:
> >
> > indicator-column
>
> Make this 'findicator-column='. Does that help?
Yes, with that change, the option & argument are passed. But ... why?
It's my understanding that the -f prefix indicates a switch, meaning:
1. It does not take an argument
2. GCC accepts a -fno- alternative, automatically
3. The "f" stands for "flag", meaning on/off.
My option has no alternative, if you'll pardon the pun. I don't see
the point in confusing the user by suggesting it does.
The fine manual says:
By default, all options beginning with "f", "W" or "m" are
implicitly assumed to take a "no-" form. This form should not be
listed separately. If an option beginning with one of these
letters does not have a "no-" form, you can use the
'RejectNegative' property to reject it.
That isn't quite accurate. The "no-" form isn't "implicitly assumed".
What would "explicitly assumed" look like, btw? More accurate would be
to say a "fno-" form is automatically accepted or generated. Computer
code does not make assumptions; programmers do.
Elsewhere:
* An option definition record. These records have the following
fields:
1. the name of the option, with the leading "-" removed
2. a space-separated list of option properties (*note Option
properties::)
3. the help text to use for '--help' (omitted if the second field
contains the 'Undocumented' property).
Nowhere is it suggested that options that take arguments should have a
leading "f" or trailing "=".
The *name* of the option doesn't include "="; it can be invoked Joined
or Separate. Why does adding the "=" even work?
> doc/options.texi describes options relative well, I think.
That's good to know; at least you're not telling me it's horribly out
of date. I am puzzled, though, because AFAICT that document doen't
indicate why a leading "f" or trailing "=" controls whether or not an
option taking an argument is passed to the compiler.
Regards,
--jkl
