Re: Global Constructors and Shared Libraries

[Mark Klein <mklein at dis dot com>]

At 12:26 AM 6/26/00 +0200, Martin v. Loewis wrote:

>2b) On systems without such a section, collecting is deferred to the
>     time when main executable is linked. At that time, a function
>     __main is constructed, which invokes all the functions. In turn,
>     when the compiler encounters main, it adds an implicit call to
>     __main. I believe __main will have only a single initializer
>     function per shared library, so that recollection is not needed
>     when a shared library changes - only when it changes so much that
>     it needs initialization now, but didn't before.

Ah .. the missing piece! Thanks!

So collect should emit some "global initializer" into the library that
__main can invoke, and therefore invoke each constructor in the library?
I don't see my version of collect doing this, so there must be some
switches I'm missing in my build?

Also, what happens when one has a dependency chain such as:

    myprog --> sharedlib1 --> sharedlib2 --> libstdc++.sl --> libc.sl

I assume that the initializer function must be uniquely named between
the two libraries. What controls that? Does that also imply I can
rebuild sharedlib2 without relinking myprog?

TIA!

Regards,


M.
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Mark Klein                                 DIS International, Ltd.
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