[cfe-commits] [PATCH] Tagging NSLog/NSLogv with the __NSString__ format instead of __printf__ format

[Jean-Daniel Dupas]

Le 21 janv. 2012 à 02:07, Eli Friedman a écrit :

> On Fri, Jan 20, 2012 at 5:03 PM, Jean-Daniel Dupas
> <devlists at shadowlab.org> wrote:
>> 
>> Le 20 janv. 2012 à 23:44, Eli Friedman a écrit :
>> 
>>> On Fri, Jan 20, 2012 at 2:09 PM, Jean-Daniel Dupas
>>> <devlists at shadowlab.org> wrote:
>>>> Hi,
>>>> 
>>>> Actually, clang automatically add a "format(printf)" attribute to the declarations of NSLog/NSLogv functions.
>>>> This is actually wrong, as NSLog expect an NSString format attribute. It is not really an issue as the code that checks the format string is the same for printf and NSString,
>>>> but actually I'm working on adding support for CFString format, and having the wrong tag on NSLog functions prevent some code factoring between CFString and NSString format checking.
>>>> 
>>>> Now that NSString format is properly checked, this trick is no longer needed, so I'd like to stop forcing the type to printf, and use NSString instead.
>>>> 
>>>> This patch also reduce the scope of this hack to objc code only (so if by any change someone write a C library with an NSLog function, clang will not try to tag it with an NSString format attribute).
>>> 
>>> If you're going to be in the area anyway, can you get rid of the hack
>>> altogether and add definitions of these functions into Builtins.def?
>>> These functions shouldn't need any special logic.
>>> 
>>> -Eli
>> 
>> 
>> I have nothing against completely removing this hack, especially as these functions are properly declared in the Foundation headers,
>> but is it worth putting a definition in Builtins.def ? Unlike other objc functions defined in Builtins.def, NSLog functions are not part of the runtime.
> 
> Strictly speaking, it isn't, but we're already pretending it is anyway
> by marking it with a format attribute, no?
> 
> -Eli


Yes, we were doing it. My question was more "Is there any good reason to continue to pretend it" ?
I just don't know why they where hard-coded in the first place.

Anyway, I will have a look at what should be done to add them in Builtins.def. It will require a little work as the string format used to defined the attributes does not support 'NSString' format out of the box.
It supports only printf and scanf currently.


-- Jean-Daniel