[PATCH 1/4] perf vendor events: Syntax corrections in Neoverse N1 json

[Andi Kleen]

On 10/6/2021 9:26 AM, John Garry wrote:
> On 06/10/2021 09:43, James Clark wrote:
>
> + Andi
>
>>
>>
>> On 05/10/2021 11:10, John Garry wrote:
>>> On 04/10/2021 17:00, Andrew Kilroy wrote:
>>>> There are some syntactical mistakes in the json files for the 
>>>> Cortex A76
>>>> N1 (Neoverse N1).  This was obstructing parsing from an external tool.
>>>
>>> If the trailing comma is not allowed by standard, then maybe we 
>>> should fix our parsing tool to not allow it also. However maybe 
>>> there is a good reason why we allow it..
>>
>> It would be nice to do, because I have also made similar fixes 
>> before. We looked at the STRICT option
>> in the parser (https://github.com/zserge/jsmn), but even then it 
>> seems to allow trailing commas.
>>
>> Trailing commas are not allowed in the json standard, but there is a 
>> split between parsers
>> where some allow it and others don't. Specifically the Python parser 
>> doesn't allow it, and Python
>> can easily be involved in some workflow that parses these files.
>>
>> The only way forwards I can think of is either getting a change 
>> accepted upstream to the parser
>> and then updating it in perf, switching to a different parser, or 
>> doing some hack to add an extra
>> step in perf to look for commas. None of which sound ideal.
>>
>
> Looking at the license in jsmn.c, we seem to be ok to modify it (to 
> error on non-standard trailing ',') - that parser has already 
> apparently been modified in mainline.
>
> If we do that then I hope that there are not to many violations in out 
> JSONs, including downstream.


Sure we can modify the file. I already did some minor changes when I 
submitted it originally.

-Andi