Re: [RFC] Enable GDB handle compressed target.xml returned by GDB stub

[Pedro Alves <palves at redhat dot com>]

On 06/13/2012 12:57 PM, Terry Guo wrote:

> 
>> -----Original Message-----
>> From: Jonathan Larmour [mailto:jifl@ecoscentric.com]
>> Sent: Wednesday, June 13, 2012 12:24 AM
>> To: Ulrich Weigand
>> Cc: Yao Qi; Terry Guo; gdb-patches@sourceware.org; tromey@redhat.com;
>> Richard Earnshaw; 'Pedro Alves'; Joey Ye
>> Subject: Re: [RFC] Enable GDB handle compressed target.xml returned by
>> GDB stub
>>
>> On 12/06/12 13:56, Ulrich Weigand wrote:
>>> Yao Qi wrote:
>>>> I'd like GDB keeps using qXfer:features:read:target.xml to fetch the
>> xml
>>>> file, even it is compressed.  We need some changes on qSupported in
>> both
>>>> sides,
>>>
>>> That still makes the result of qXfer:features:read:target.xml
>> dependent
>>> on global state ...   Why not simply support compressed files by
>> having
>>> the stub respond to
>>>    qXfer:features:read:target.xml.gz
>>> (etc) if it has a compressed file image?
>>>
>>> Optionally we might still add a qSupported feature as you describe;
>>> otherwise GDB might just probe whether the stub knows .gz files.
>>
>> For what it's worth, that sounds appealing to me. Strictly Terry's
>> proposal wasn't a .true gz file but a gzipped stream. But that's easy
>> to
>> avoid if we just choose to use the name convention target.xmlz or
>> suchlike.
>>
>> Jifl
> 
> So the whole process can be simplified to:
> 
> Step 1: GDB just sends "qXfer:features:read:target.xml.gz" to stub to try to
> get a compressed xml file.
> Step 2: If stub supports compressed xml, then it sends it to GDB. Otherwise
> nothing get replied.
> Step 3: If GDB gets something, then it proceeds to decompress the xml file
> and go ahead. If get nothing, GDB sends " qXfer:features:read:target.xml" to
> try to request the plain xml file.
> 
> For GDB that doesn't support compressed xml file, the
> "qXfer:features:read:target.xml.gz" will never be used.
> 
> How about the above model?


Please don't consider only target.xml in the design, but also the xi:includes.

-- 
Pedro Alves