MI to access value of $ prefixed variable name

[Simon Marchi]

On 2021-05-25 12:35 a.m., Jonah Graham wrote:
> Hello,
> 
> I have a user of Eclipse CDT who is having problems displaying a C variable
> called $j (dollar sign prefixed variable) -
> https://bugs.eclipse.org/bugs/show_bug.cgi?id=573703
> 
> I understand this is because $ prefixed variables are treated specially by
> GDB.
> 
> 47-stack-list-locals --thread 1 --frame 0 1
> 47^done,locals=[{name="$f",value="0"}]
> 
> 52-var-create --thread 1 --frame 0 - * $f
> 52^done,name="var3",numchild="0",value="void",type="void",has_more="0"
> 
> Note type "void" above, $f is an int in the C code, but is indeed void (as
> expected) in GDB. -stack-list-locals shows the correct value, but I can't
> use the returned name back to -var-create because of the naming conflict.
> 
> There wasn't anything I saw in the help (
> https://sourceware.org/gdb/onlinedocs/gdb/GDB_002fMI-Variable-Objects.html)
> on this topic.

Huh, I didn't know this was possible:

https://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar-Signs

I didn't look in depth, but I don't think there's a way to make it work.
I don't remember seeing a way to escape that dollar sign.

I'd say that the simplest solution would be: don't use dollar sign in
identifiers.  But if somebody really wants GDB to support it, then they
can always send a patch for it (I don't think this is a priority for
anyone).

Simon