[Pythonmac-SIG] making a C extension compatible across OS versions?

[gandreas@gandreas.com]

On May 26, 2005, at 1:56 PM, has wrote:

> Nicholas Riley wrote:
>
>
>>> Obviously the extension needs to be built on Tiger to provide sdef
>>> support, but what should I do to ensure that, say, applications
>>> containing that binary extension will still work OK when run on
>>> earlier OSes?
>>>
>>
>> You can use weak linking if you don't need to support 10.1.x or
>> earlier,
>>
>
> Ah, thanks. nm says OSACopyScriptingDefinition is weak, so I've  
> added the appropriate 'OSACopyScriptingDefinition != NULL' check to  
> OSATerminology.c and recompiled it for Tiger's Apple-installed  
> Python. No problems using it there there, of course, but I do get  
> the following (unrelated) error when trying to import it into user- 
> installed Python 2.3.5 on 10.2.8 (I don't have a copy of Panther so  
> dunno if it works on that):
>
> ImportError: Failure linking new module: /usr/lib/libmx.A.dylib:  
> dyld: /Library/Frameworks/Python.framework/Versions/2.3/Resources/ 
> Python.app/Contents/MacOS/Python can't open library: /usr/lib/ 
> libmx.A.dylib  (No such file or directory, errno = 2)

gcc 4.0 automatically adds a reference to /usr/lib/libmx.A.dylib for  
all C++ code (and to make it more annoying, in more than a few cases,  
it doesn't actually directly reference anything in it - you'd think  
the linker would skip adding the link record).

Switching to gcc 3.3 will make this problem go away.


Glenn Andreas                      gandreas at gandreas.com
  <http://www.gandreas.com/> wicked fun!
Widgetarium | the quickest path to widgets