Re: [Python-Dev] Stable ABI

2018-06-03 Thread Eric V. Smith 

On 6/3/2018 10:55 AM, Christian Tismer wrote:

On 03.06.18 13:18, Ronald Oussoren wrote:




On 3 Jun 2018, at 12:03, Christian Tismer  wrote:

...



I have written a script that scans all relevant header files
and analyses all sections which are reachable in the limited API
context.
All macros that don't begin with an underscore which contain
a "->tp_" string are the locations which will break.

I found exactly 7 locations where this is the case.

My PR will contain the 7 fixes plus the analysis script
to go into tools. Preparind that in the evening.


Having tests would still be nice to detect changes to the stable ABI when they 
are made.

Writing those tests is quite some work though, especially if those at least 
smoke test the limited ABI by compiling snippets the use all symbols that 
should be exposed by the limited ABI. Writing those tests should be fairly 
simple for someone that knows how to write C extensions, but is some work.

Writing a tests that complain when the headers expose symbols that shouldn’t be 
exposed is harder, due to the need to parse headers (either by hacking 
something together using regular expressions, or by using tools like gccxml or 
clang’s C API).


What do you mean?
My script does that with all "tp_*" type fields.
What else would you want to check?


I think Ronald is saying we're trying to answer a few questions:

1. Did we accidentally drop anything from the stable ABI?

2. Did we add anything to the stable ABI that we didn't mean to?

3. (and one of mine): Does the stable ABI already contain things that we 
don't expect it to?


Eric
___
Python-Dev mailing list
Python-Dev@python.org
https://mail.python.org/mailman/listinfo/python-dev
Unsubscribe: 
https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com

Re: [Python-Dev] Stable ABI

2018-06-03 Thread Christian Tismer 
On 03.06.18 13:18, Ronald Oussoren wrote:
> 
> 
>> On 3 Jun 2018, at 12:03, Christian Tismer  wrote:
...

>>
>> I have written a script that scans all relevant header files
>> and analyses all sections which are reachable in the limited API
>> context.
>> All macros that don't begin with an underscore which contain
>> a "->tp_" string are the locations which will break.
>>
>> I found exactly 7 locations where this is the case.
>>
>> My PR will contain the 7 fixes plus the analysis script
>> to go into tools. Preparind that in the evening.
> 
> Having tests would still be nice to detect changes to the stable ABI when 
> they are made. 
> 
> Writing those tests is quite some work though, especially if those at least 
> smoke test the limited ABI by compiling snippets the use all symbols that 
> should be exposed by the limited ABI. Writing those tests should be fairly 
> simple for someone that knows how to write C extensions, but is some work.
> 
> Writing a tests that complain when the headers expose symbols that shouldn’t 
> be exposed is harder, due to the need to parse headers (either by hacking 
> something together using regular expressions, or by using tools like gccxml 
> or clang’s C API).  

What do you mean?
My script does that with all "tp_*" type fields.
What else would you want to check?

-- 
Christian Tismer-Sperling:^)   tis...@stackless.com
Software Consulting  : http://www.stackless.com/
Karl-Liebknecht-Str. 121 : http://pyside.org
14482 Potsdam: GPG key -> 0xFB7BEE0E
phone +49 173 24 18 776  fax +49 (30) 700143-0023



signature.asc
Description: OpenPGP digital signature
___
Python-Dev mailing list
Python-Dev@python.org
https://mail.python.org/mailman/listinfo/python-dev
Unsubscribe: 
https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com

Re: [Python-Dev] Stable ABI

2018-06-03 Thread Ronald Oussoren 


> On 3 Jun 2018, at 12:03, Christian Tismer  wrote:
> 
> On 02.06.18 05:47, Nick Coghlan wrote:
>> On 2 June 2018 at 03:45, Jeroen Demeyer > > wrote:
>> 
>>On 2018-06-01 17:18, Nathaniel Smith wrote:
>> 
>>Unfortunately, very few people use the stable ABI currently, so it's
>>easy for things like this to get missed.
>> 
>> 
>>So there are no tests for the stable ABI in Python?
>> 
>> 
>> Unfortunately not.
>> 
>> https://bugs.python.org/issue21142 is an old issue suggesting automating
>> those checks (so we don't inadvertently add or remove symbols for
>> previously published stable ABI definitions), but it's not yet made it
>> to the state of being sufficiently well automated that it can be a
>> release checklist item in PEP 101.
>> 
>> Cheers,
>> Nick.
> 
> Actually, I think we don't need such a test any more, or we
> could use this one as a heuristic test:
> 
> I have written a script that scans all relevant header files
> and analyses all sections which are reachable in the limited API
> context.
> All macros that don't begin with an underscore which contain
> a "->tp_" string are the locations which will break.
> 
> I found exactly 7 locations where this is the case.
> 
> My PR will contain the 7 fixes plus the analysis script
> to go into tools. Preparind that in the evening.

Having tests would still be nice to detect changes to the stable ABI when they 
are made. 

Writing those tests is quite some work though, especially if those at least 
smoke test the limited ABI by compiling snippets the use all symbols that 
should be exposed by the limited ABI. Writing those tests should be fairly 
simple for someone that knows how to write C extensions, but is some work.

Writing a tests that complain when the headers expose symbols that shouldn’t be 
exposed is harder, due to the need to parse headers (either by hacking 
something together using regular expressions, or by using tools like gccxml or 
clang’s C API).  

BTW. The problem with the tool in issue 21142 is that this looks at the symbols 
exposed by lib python on linux, and that exposed more symbols than just the 
limited ABI. 
 
Ronald

___
Python-Dev mailing list
Python-Dev@python.org
https://mail.python.org/mailman/listinfo/python-dev
Unsubscribe: 
https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com

Re: [Python-Dev] Stable ABI

2018-06-03 Thread Christian Tismer 
On 02.06.18 05:47, Nick Coghlan wrote:
> On 2 June 2018 at 03:45, Jeroen Demeyer  > wrote:
> 
> On 2018-06-01 17:18, Nathaniel Smith wrote:
> 
> Unfortunately, very few people use the stable ABI currently, so it's
> easy for things like this to get missed.
> 
> 
> So there are no tests for the stable ABI in Python?
> 
> 
> Unfortunately not.
> 
> https://bugs.python.org/issue21142 is an old issue suggesting automating
> those checks (so we don't inadvertently add or remove symbols for
> previously published stable ABI definitions), but it's not yet made it
> to the state of being sufficiently well automated that it can be a
> release checklist item in PEP 101.
> 
> Cheers,
> Nick.

Actually, I think we don't need such a test any more, or we
could use this one as a heuristic test:

I have written a script that scans all relevant header files
and analyses all sections which are reachable in the limited API
context.
All macros that don't begin with an underscore which contain
a "->tp_" string are the locations which will break.

I found exactly 7 locations where this is the case.

My PR will contain the 7 fixes plus the analysis script
to go into tools. Preparind that in the evening.

cheers -- Chris

-- 
Christian Tismer-Sperling:^)   tis...@stackless.com
Software Consulting  : http://www.stackless.com/
Karl-Liebknecht-Str. 121 : http://pyside.org
14482 Potsdam: GPG key -> 0xFB7BEE0E
phone +49 173 24 18 776  fax +49 (30) 700143-0023



signature.asc
Description: OpenPGP digital signature
___
Python-Dev mailing list
Python-Dev@python.org
https://mail.python.org/mailman/listinfo/python-dev
Unsubscribe: 
https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com