Re: what happens before main()?

So things like __cxa_vec_ctor for global objects and __cxa_guard for  
all statics are actually called by dyld? (I always thought it was done  
by crt). But that shouldn't be a huge performance impact unless there  
is a big number of unmapped libraries needed by application and/or  
huge number of global objects or classes with static members. In  
latter case it's a design issue, right?

BTW, dyld is not open sourced, I guess?

BR,
Ivan


On Apr 27, 2010, at 4:35 PM, Shantonu Sen wrote:

> I don't think that would help. The kernel hands off control to dyld  
> (the dynamic linker), which is in charge of mapping all shared  
> libraries, as well as running initializers (including C++ static  
> initializers). dyld then jumps to crt1.o's entry point, which may do  
> some further initialization before entering main().
>
> Try looking at the dyld(1) man page. DYLD_PRINT_INITIALIZERS and  
> DYLD_PRINT_STATISTICS might be enlightening
>
> Shantonu
>
> Sent from my MacBook
>
> On Apr 27, 2010, at 3:42 AM, Ivan Ostres wrote:
>
>> Hi!
>>
>> To every C/C++ program, startup file is added - like /usr/lib/ 
>> crt1.o which does initializations. Since it was not compiled with - 
>> g, you can't really step through it but you could find source for  
>> it (if available) and compile it yourself and add it to your  
>> program instead of standard crt*.o. In that case you could step  
>> through it.
>>
>> Regards,
>> Ivan
>>
>> P.S. You can check gcc/ld documentation which exact startup file is  
>> linked to your program to be sure
>>
>>
>> On Apr 27, 2010, at 11:59 AM, Aya Koshigaya wrote:
>>
>>> Hi,
>>>
>>> I have a big library written in C++, in this lib there are several  
>>> static-things that get initialised at the start of the Programm,  
>>> even before the main() function is called.
>>>
>>> So far so good, but the problem is - the program takes some time  
>>> to start, and when I did some time-trackings to see where the time  
>>> goes, I found out it takes already up to 3 seconds until my main()  
>>> function is called.
>>>
>>> But, since there are about 300-400 Files it would take forever to  
>>> find the "bad" statics.. so, is there any way in Xcode to step  
>>> trough the initialisation process? Like as if I'd put a breakpoint  
>>> in the main() function and step forward.. but in the main method  
>>> it's already to late :(
>>>
>>> Aya~_______________________________________________
>>> MacOSX-dev mailing list
>>> [email protected]
>>> http://www.omnigroup.com/mailman/listinfo/macosx-dev
>>>
>>
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