On 12/19/2011 05:10 PM, Anthony Liguori wrote:
> On 12/19/2011 09:04 AM, Avi Kivity wrote:
>> On 12/19/2011 04:50 PM, Anthony Liguori wrote:
>>>> +static int cmp_flatrange_addr(const void *_addr, const void *_fr)
>>>> +{
>>>> + const AddrRange *addr = _addr;
>>>> + const FlatRange *fr = _fr;
>>>
>>>
>>> Please don't prefix with an underscore.
>>
>> Why not? It's legal according to the standards, if that's your concern
>> (only _[_A-Z]+ are reserved).
>
> http://www.gnu.org/s/hello/manual/libc/Reserved-Names.html
>
> "In addition to the names documented in this manual, reserved names
> include all external identifiers (global functions and variables) that
> begin with an underscore (‘_’)"
>
> Now that might just mean that you're shadowing a global name, so maybe
> that's okay, but I think it's easier to just enforce a consistent rule
> of, "don't start identifiers with an underscore".
I rather like the pattern
void callback(void *_foo)
{
Foo *foo = _foo;
...
}
If the consensus is that we don't want it, I'll change it, but I do
think it's useful.
>>>> +MemoryRegionSection memory_region_find(MemoryRegion *address_space,
>>>> + target_phys_addr_t addr,
>>>> uint64_t size);
>>>
>>>
>>> Returning structs by value is a bit unexpected.
>>
>> It's just prejudice, here's the call sequence:
>
> It's not about whether it's fast or slow. It's just unexpected.
It's plain C, I don't see why it's so unexpected.
>
> Instead of returning a NULL pointer on error, you set .mr to NULL if
> an error occurs (which isn't documented by the comment btw).
> Returning a pointer, or taking a pointer and returning a 0/-1 return
> value makes for a more consistent semantic with the rest of the code
> base.
>
How can I return a pointer? If I allocate it, someone has to free it.
If I pass it as a parameter, we end up with a silly looking calling
convention. If I return an error code, the caller has to set up an
additional variable.
The natural check is section.size which is always meaningful -
memory_region_find() returns a subrange of the input, which may be
zero. You're right that I should document it (and I should use it
consistently).
--
error compiling committee.c: too many arguments to function
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