Re: [Qemu-devel] [RFC for-2.7 01/11] qdt: IEEE1275-style device tree utility code

[Thomas Huth]

On 27.04.2016 09:28, Markus Armbruster wrote:
> Thomas Huth <address@hidden> writes:
> 
>> On 27.04.2016 08:43, Markus Armbruster wrote:
>>> David Gibson <address@hidden> writes:
>>>
>>>> On Tue, Apr 26, 2016 at 01:00:06PM +0200, Thomas Huth wrote:
>>>>> On 20.04.2016 04:33, David Gibson wrote:
>> [...]
>>>>>> +/*
>>>>>> + * Property functions
>>>>>> + */
>>>>>> +
>>>>>> +QDTProperty *qdt_new_property(const gchar *name, gconstpointer val, 
>>>>>> gsize len)
>>>>>> +{
>>>>>> +    QDTProperty *prop = g_malloc0(sizeof(*prop) + len);
>>>>>> +
>>>>>> +    prop->name = g_strdup(name);
>>>>>> +    prop->len = len;
>>>>>> +    memcpy(prop->val, val, len);
>>>>>> +    return prop;
>>>>>> +}
>>>>>> +
>>>>>> +static QDTProperty *getprop_(const QDTNode *node, const gchar *name)
>>>>>
>>>>> Underscore at the end looks somewhat strange ... can't you simply drop 
>>>>> that?
>>>>
>>>> Well.. the idea was that the _ versions are the "internal" ones,
>>>> whereas external users will generally use the non-underscore version
>>>
>>> I've seen that convention used before.  It's fine with me.
>>
>> Can't remember to have seen that convention before ... I know that some
>> people use the underscore at the beginning to mark an internal function,
>> but at the end?
>> So if you really want to use the underscore, what about putting it at
>> the beginning instead?
> 
> C99 7.1.3  Reserved identifiers:
> 
>          -- All identifiers  that  begin  with  an  underscore  are
>             always  reserved for use as identifiers with file scope
>             in both the ordinary and tag name spaces.

Oh, I always thought that underscore + lowercase letter would still be
OK for local variables and functions, since for example
http://www.gnu.org/software/libc/manual/html_node/Reserved-Names.html says:

"In addition to the names documented in this manual, reserved names
include all external identifiers (global functions and variables) that
begin with an underscore (‘_’) and all identifiers regardless of use
that begin with either two underscores or an underscore followed by a
capital letter are reserved names"

... that sounds like the underscore rule only applies to global
functions and variables (and to those where the underscore is followed
by a capital letter or another underscore).

But if I've got your quote right, a leading underscore _always_
indicates a reserved name for functions and variables, no matter whether
they are local or global... Well, you learn something new
every day :-)

 Thomas