Re: [Pyobjc-dev] Can't bridge UCConvertUTCDateTimeToCFAbsoluteTime

[Ben A. <be...@ar...>]

On Nov 26, 2007, at 3:17 PM, blake wrote:

>> I am trying to bridge UCConvertUTCDateTimeToCFAbsoluteTime using
>> PyObjC in Leopard.
>>
>> The problem that I am running into is that
>> UCConvertUTCDateTimeToCFAbsoluteTime takes a struct that's declared
>> (on 32 bits) as {unsigned short; unsigned long; unsigned short;}  
>> using
>> packed alignment, which means that the offset of the 4-byte long
>> member is 2. When I use {UTCDateTime=SLS}, PyObjC puts the 4-byte  
>> long
>> at offset 4, which then causes problems down the line.
>>
>> Looking at PyObjC source, I don't see a way to force custom alignment
>> of struct members.
>>
>> Did I miss some mechanism for handling this? What are my option?  
>> Thanks,
>
> The problem appears to be that no metadata exists for <CarbonCore/ 
> UTCUtils.h>. You might try running gen_bridge_metadata(1) on  
> CarbonCore.framework, or typecast UTCDateTime to int64_t instead.

I believe you misunderstood my problem. I am trying to provide the  
bridge metadata myself, and I believe that it is *impossible* to  
provide appropriate bridge metadata because the metadata support as it  
exists right now does not allow bridging a struct that is aligned as  
UTCDateTime (obviously, without writing my own bridge function for  
UCConvertUTCDateTimeToCFAbsoluteTime -- if I write my own, I can do  
anything I want).

Also, documentation for UTCDateTime specifically says that it's wrong  
to access it at uint64_t, so that advice is incorrect.

Ben

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