[Crash-utility] Extension modules in C++

[David Mair]

Hi Dave,

On 08/08/2012 09:24 AM, Dave Anderson wrote:
> 
> 
> ----- Original Message -----
>>
>>
>> ----- Original Message -----
>>> Dne Čt 26. července 2012 14:02:56 Adrien Kunysz napsal(a):
>>>> On Thu, Jul 26, 2012 at 10:57 AM, Petr Tesarik <ptesarik at suse.cz>
>>>> wrote:
>>>>> Hi all,
>>>>>
>>>>> as part of SUSE HackWeek8, David started work on a GUI extension using
>>>>> Qt4, which is a C++ project. One of the early annoyances is that an
>>>>> extension module must include the declarations from defs.h, and we
>>>>> currently use some C identifiers which happen to be keywords in C++,
>>>>> namely:
>>>>>
>>>>> - struct namespace
>>>>> - struct namespace namespace (in struct symbol_table_data)
>>>>> - char *typename (in struct gnu_request)
>>
>> And it seems that "namespace" is used for other purposes in files
>> like ppc.c and ppc64.c...
> 
> Of course that's irrelevant to the discussion...
>  
>> The "typename" is changeable, in fact I don't think it's really used
>> except for debugging purposes, although it would break the capability
>> of using other (earlier) versions of gdb.  I would say that most people
>> use the most recent gdb version, but it always seems that there's somebody
>> still doing things differently.  But that could be dealt with by #ifdef'ing
>> the structure member declaration in defs.h based upon the relevant GDB_X_X
>> setting, because gdb/symtab.c wouldn't see it.  Kind of ugly,
>> though...
>>
>>>>>
>>>>> Can I rename them? But you said earlier that the existing API must never
>>>>> change... Any other suggestions to make this include file parseable by a
>>>>> C++ compiler?
>>>>
>>>> One hack you could consider would be to do something like this:
>>>>
>>>> extern "C" {
>>>>         #define namespace ns
>>>>         #include "defs.h"
>>>>         #undef namespace
>>>> }
>>>
>>> Yes! That works, although I'm not entirely sure it can't do any harm.
>>> After all, it's what you called it - a hack. ;-)
>>
>> But it can't harm the crash utility, right?  ;-)
>>  
>>> I wonder whether Dave (Anderson) can suggest a cleaner solution (or make an
>>> official statement that he doesn't care about C++ compatibility).
>>>
>>> Petr Tesarik
>>> SUSE Linux
>>  
>> To be honest, I really don't care about C++ compatibility -- with the realization
>> that I'm already offending somebody.  If Adrien's suggestion works, I suppose I'd
>> prefer to keep things as they are.  But if you really want to submit a patch,
>> I'll entertain it as always...
>>
>> Dave
> 
> Petr,
> 
> On second thought, I'll just take of this in crash-6.0.9.  It's not 
> that big a deal...

I noted the changes to defs.h in 6.0.9 that permitted me to include it
without macros to rename uses of namespace and typename. Thanks for
putting the time into it.

-- 
David Mair.