Re: [PATCH] gdb: check for groups with duplicate names in reggroups:add

[Simon Marchi <simon.marchi@efficios.com>]

On 10/18/22 14:42, Tom Tromey wrote:
>>>>>> "Simon" == Simon Marchi via Gdb-patches <gdb-patches@sourceware.org> writes:
> 
> Simon> In the downstream ROCm GDB port, we would create multiple register
> Simon> groups with duplicate names.  While it did not really hurt, it certainly
> Simon> wasn't the intent.  And I don't think it ever makes sense to do so.
> 
> Simon> To catch these, change the assert in reggroups::add to check for
> Simon> duplicate names.  It's no longer necessary to check for duplicate
> Simon> reggroup pointers, because adding the same group twice would be caught
> Simon> by the duplicate name check.
> 
> I haven't looked but would it be possible for malformed XML from the
> target to trigger this assert?
> 
> Tom

I don't think so, because the target description support code creates
the groups as it finds them while iterating registers.  It only creates
a group if it doesn't exist already:

  https://gitlab.com/gnutools/binutils-gdb/-/blob/152cc35ebff44eb06a00364ca1dbcf5fca6772b4/gdb/target-descriptions.c#L1124-1125

In other words, the XML tdesc doesn't have a list of groups, where if a
group was duplicated, it could trigger this assert.

Simon