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

[Jonah Graham <jonah at kichwacoders dot com>]

On 23 November 2016 at 23:04, Luis Machado <lgustavo@codesourcery.com> wrote:
> 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.
>

There is no way I know of, as a reference
http://python3porting.com/differences.html#long recommends doing it
(roughly) the way already done in python/lib/gdb/printing.py and
copied to python/lib/gdb/printer/bound_registers.py

Thanks for the review,
Jonah