Re: [patch[ Improve the error messages of tvariable command

["Abid, Hafiz" <hafiz_abid at mentor dot com>]

On 13/02/13 16:47:38, Pedro Alves wrote:
> I somewhat remember investigating this, and writing a longer
> rationale for the change -- the gist of it being not
> handling tsv name as expressions.   Can you dig it out from
> the internal archives and repost including that info?  It'd
> be good for posterity.
>
> --
> Pedro Alves

Here is what I found. Is it what you were expecting?

--

Here's a fix for issue #8161, which is about the "tvariable" returning
errors on invalid and tsv names.  E.g.,

 Temporary breakpoint 1, main () at a.cc:2
 2           int x = 1;
 (gdb) tvar x
 Syntax must be $NAME [ = EXPR ]
 (gdb) tvar y
 No symbol "y" in current context.

The problem is the use of parse_expression to parse the tvariable's
name.  We could merely always catch errors thrown from within
parse_expression, and issue a "usage" error, but it wouldn't cover
all cases correctly.  E.g.,

 (gdb) tvar x = nonexistingvariable

is an invalid expression, not invalid syntax.

I also noticed that

 (gdb) tvar x = 1 = 1

would be incorrectly accepted.

Given that the comand is documented to only take an expression
on the right side of the '=', it seems that whatever is on
the left side of the '=' should not be treated as an expression, but
literaly as "$NAME".  That's what the patch does.

MI now shares the same name validations as the CLI variant.

--

Regards,
Abid