Make pretty printers version namespace dependant

[Jonathan Wakely]

On 27/04/17 21:27 +0200, François Dumont wrote:
>On 27/04/2017 20:32, Jonathan Wakely wrote:
>>On 27/04/17 20:12 +0200, François Dumont wrote:
>>>Hi
>>>
>>>   Here is the patch to registers Printers depending on activation 
>>>of versioned namespace.
>>>
>>>2017-04-27  François Dumont  <fdumont@gcc.gnu.org>
>>>
>>>   * python/Makefile.am [ENABLE_SYMVERS_GNU_NAMESPACE]
>>>   (user_versioned_namespace): New.
>>>   (gdb.py): Adapt target.
>>>   * python/Makefile.in: Regenerate.
>>>   * python/hook.in: Likewise.
>>>   * python/libstdcxx/v6/printers.py (add_one_template_type_printer):
>>>   Register only 1 Printer type depending on _versioned_namespace value.
>>>   (add_one_type_printer): Likewise.
>>>   (register_libstdcxx_printers): Add parameter use_versioned_namespace.
>>>   Adapt _versioned_namespace value based on it.
>>>   * testsuite/lib/gdb-test.exp (get_use_versioned_namespace): New.
>>>   (note-test): Detect if version namespace is active and pass the
>>>   information to register_libstdcxx_printers.
>>>   * testsuite/libstdc++-prettyprinters/48362.cc: Replace a regexp-test
>>>   by a note-test.
>>>
>>>Tested under Linux x86_64, with and without version namespace.
>>>
>>>Ok to commit to trunk ?
>>
>>What's the advantage?
>>
>>Again, the point of my patch was to optimise if needed. Is it needed?
>
>Oh, I thought it was obviously better to not register useless 
>Printers. But if you need a bug report or an explicit test showing 
>that it is better then I don't have it. Maybe a gdb guy could tell us 
>if it worth it.

I think I've asked t he GDB guys before about the overhead of
printers, but I'll check with them. I don't think having extra
printers registered is a problem (GDB is usually an interactive
program, so the time it takes to find a printer is not significant on
"human scales").

>Do I just keep the small cleanup on the useless usage of regexp-test 
>in 48362.cc ?

That part is fine now, thanks.


>>
>>
>>>Are we going to wait for gcc 7.1 before bumping version namespace ?
>>
>>Shouldn't we wait until we change something that would require bumping
>>it? :-)
>
>Ok, I'll add it to my first patch needing it.
>
>Is it the right moment to do so ?

I think changes that only affect the versioned namespace are OK for
trunk now.