Re: Quoting, backslashes, CLI and MI

[Daniel Jacobowitz <drow at false dot org>]

On Wed, Feb 22, 2006 at 09:22:18PM +0200, Eli Zaretskii wrote:
> > Date: Tue, 21 Feb 2006 16:33:24 -0500
> > From: Daniel Jacobowitz <drow@false.org>
> > 
> > I think that we want to continue using buildargv-style quoting for CLI
> > commands, and that it would be desirable to use only MI-style
> > quoting for MI commands.
> 
> I agree.  But that means MI commands that delegate to CLI will have to
> process the arguments to modify the quoting, right?

Right - or stop delegating to the CLI, which is what I think I would
do.  Especially since it turned out that there were only about a dozen.

> > So I think that we should take this opportunity to fix up all MI
> > commands to quote like the documentation says they do.
> 
> It would be good to fix that now, yes.
> 
> However, I Think we need 2 different styles of quoting: one for file
> names, the other for strings.  Otherwise, supporting the Windows
> backslashes will be hard.  Also, there are messy cases such as this:
> 
>     (gdb) break "foo bar.c":'MyClass::MyMethod'
> 
> (I'm not even sure I quoted it correctly ;-).  Can we really use the
> same quoting rules for both the file-name and class/method name in
> such situations?

Well, are you talking about the CLI here, or about the MI?

Supporting Windows backslashes isn't hard - but we would have to
document that they must be doubled (A) on the CLI, and (B) within
double-quoted MI arguments.  Which is already how things work in many
cases; for instance:

(gdb) file .\T_MATH.elf
.T_MATH.elf: No such file or directory.
(gdb) file .\\T_MATH.elf
Reading symbols...

I'd like for the quoting rules to be independent of what's being
quoted.

Break is a particularly confusing example that I had not considered in
depth.  linespec.c needs to receive the quotes, because they affect how
the linespec is interpreted (which I think is somewhat horrid, but
anyway, moving on, leave that for another day).  In MI, this means you
ought to be doing things like this, for your example:

(gdb) break "foo bar.c":'MyClass::MyMethod'

-break-insert "\"foo bar.c\":'MyClass::MyMethod'"

Fortunately, -break-insert is already a real MI command - so this is
already how it behaves.

> > I'd like to fix up all the CLI and "set" commands to use buildargv style
> > quoting, too.
> 
> If you agree with me on the two quoting styles, you will also agree
> that we need two different flavors of buildargv.

I don't think I agree, although Jim's pointed out "set args" and
var_*integer, so not all set commands can be handled this way.
Some new documentation will definitely be written!

> > Andrew Cagney pointed out in a PR that we might need to update the
> > readline filename completion, too.  I'm not sure if that's still relevant,
> > it needs a third look.
> 
> It's relevant, at least wrt backslashes in Windows file names: if you
> type TAB with backslash being the last character, completion won't
> work (it does TRT when there are backslashes further to the left of
> the cursor, though).  Also, quoted file names, with or without
> whitespace, aren't completed correctly, no matter if they use forward
> or backslashes.

Thanks.  Another day, another bug.

-- 
Daniel Jacobowitz
CodeSourcery