Re: [PATCH] bound_registers.py: Add support for Python 3

[Luis Machado <lgustavo@codesourcery.com>]

On 11/23/2016 04:39 PM, Jonah Graham wrote:
> On 23 November 2016 at 16:59, Luis Machado <lgustavo@codesourcery.com> wrote:
>> On 11/20/2016 02:45 PM, Jonah Graham wrote:
>>>
>>> gdb/Changelog:
>>>
>>>         * python/lib/gdb/printer/bound_registers.py: Add support
>>>         for Python 3.
>>> ---
>>>  gdb/ChangeLog                                 | 5 +++++
>>>  gdb/python/lib/gdb/printer/bound_registers.py | 5 +++++
>>>  2 files changed, 10 insertions(+)
>>>
>>> diff --git a/gdb/ChangeLog b/gdb/ChangeLog
>>> index 3797e8b..1923888 100644
>>> --- a/gdb/ChangeLog
>>> +++ b/gdb/ChangeLog
>>> @@ -1,3 +1,8 @@
>>> +2016-11-20  Jonah Graham  <jonah@kichwacoders.com>
>>> +
>>> +       * python/lib/gdb/printer/bound_registers.py: Add support
>>> +       for Python 3.
>>> +
>>>  2016-11-19  Joel Brobecker  <brobecker@adacore.com>
>>>
>>>         * contrib/ari/gdb_ari.sh: Add detection of printf_vma and
>>> diff --git a/gdb/python/lib/gdb/printer/bound_registers.py
>>> b/gdb/python/lib/gdb/printer/bound_registers.py
>>> index 9ff94aa..e91cc19 100644
>>> --- a/gdb/python/lib/gdb/printer/bound_registers.py
>>> +++ b/gdb/python/lib/gdb/printer/bound_registers.py
>>> @@ -16,6 +16,11 @@
>>>
>>>  import gdb.printing
>>>
>>> +if sys.version_info[0] > 2:
>>> +    # Python 3 removed basestring and long
>>> +    basestring = str
>>> +    long = int
>>> +
>>>  class MpxBound128Printer:
>>>      """Adds size field to a mpx __gdb_builtin_type_bound128 type."""
>>>
>>>
>>
>> Since this should apply to every python module, maybe this should be defined
>> inside gdb/python/lib/gdb/__init__.py?
>>
>> I'm assuming it gets included by module "gdb" and therefore "long" is
>> defined to be "int" for Python versions > 3.
>>
>> Then we can remove that code from gdb/python/lib/gdb/printing.py (and from
>> other places setting this type of version-specific adjustment).
>>
>> Does that make sense?
>
> Hi Luis,
>
> I am not sure I understand how to do it in __init__.py as the modules
> that wanted to be both Python 2 and Python 3 compatible would still
> have to have special code. AFAIK an __init__.py cannot change the
> value of long in other py files. So python/lib/gdb/printing.py and
> python/lib/gdb/printer/bound_registers.py would still need special
> case code locally, even if that special case was an import for a
> definition of long.

That was the point i wasn't sure about (not a Python expert). I see 
conditional code executing if the version is > 3, but i wasn't sure if 
it would take effect globally when a module is included.

In that case, i suppose there is not much that can be done other than 
duplicate the code.