Re: [Pyobjc-dev] instrumentObjcMessageSends

[Ronald O. <ron...@ma...>]

On 8 Jan, 2008, at 0:09, Michael McCracken wrote:

> On Jan 6, 2008 11:10 PM, Ronald Oussoren <ron...@ma...>  
> wrote:
>>
>> On 6 Jan, 2008, at 21:21, Jon Christopher wrote:
>>
>>> Many apologies if this is the wrong place to ask this question,  
>>> but I
>>> couldn't find anywhere else.
>>>
>>> I'd like to call the instrumentObjcMessageSends(YES)  function which
>>> is part of the objc runtime so that I can log all objc-messages,  
>>> but I
>>> can't figure out how to access it from python.
>>> This function has the same effect as  
>>> NSObjCMessageLoggingEnabled=TRUE
>>> (see http://developer.apple.com/technotes/tn2004/tn2124.html)
>>>
>>> I can create and call objc classes, but instrumentObjcMessageSends  
>>> is
>>> a free function.  I'd appreciate any pointers as to how to call this
>>> function, or runtime free functions in general, for that matter.
>>
>> You cannot easily call runtime functions.  Because
>> instrumentObjcMessageSends isn't a public API I won't add it to  
>> PyObjC.
>>
>> It should be possible to call it using objc.loadBundleFunctions,  
>> but I
>> don't have time to look into that right now.
>>
>
> Wouldn't it be possible to just wrap that function with a C  
> extension module?
>
> Or if you really want every message send, just add it to your main.m?

That's also possible. This should do the trick for calling it in pure  
python:

import objc
import Foundation

objc.loadBundleFunctions(Foundation.__bundle__, globals(),
         [
             ('instrumentObjcMessageSends', objc._C_VOID +  
objc._C_NSBOOL),
         ])

Then use 'instrumentObjcMessageSends(1)' to enable logging. This  
assumes the prototype for the function is 'void  
instrumentObjcMessageSends(BOOL)'.

I've tried this without getting a possitive result though. According  
to <http://lists.apple.com/archives/darwin-dev/2005/Jul/msg00027.html>  
you have to call another function as well, which has a callback  
function to perform the actual logging.

I guess it would be easier to just implement this is a small C  
extension after all.

Ronald