Date:	Wed, 15 Oct 1997 18:03:35 -0700 (PDT)
Message-Id:	<199710160103.SAA04722@adit.ap.net>
Mime-Version:	1.0
To:	"Salvador Eduardo Tropea (SET)" <salvador AT inti DOT edu DOT ar>,
	Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>, blizzar AT hem1 DOT passagen DOT se
From:	Nate Eldredge <eldredge AT ap DOT net>
Subject:	Re: RHIDE Question.
Cc:	djgpp AT delorie DOT com

At 04:32  10/15/1997 +0000, Salvador Eduardo Tropea (SET) wrote:
>Eli Zaretskii <eliz AT is DOT elta DOT co DOT il> wrote:

>> However, I think I have a case where the link order really is
>> important.  This is when one or more of the modules being linked use
>> functions with `__attribute__((constructor))' or ((destructor)).
>> 
>> For example, imagine that a program uses Filesystem Extensions to
>> install handlers for some special files, and uses the constructor
>> attribute to make the installation happen before `main' gets called.
>> 
>> These functions will be invoked by the startup/exit code in the order
>> they are seen by the linker.  And that order might be important,
>> e.g. when one function needs to install itself ahead of others, so it
>> sees the calls first.
>I faced this problem with constructors of classes and library functions that 
>must be initialized before the constructor. I think the best way is to call
the 
>initialization of the other module from the constructor. If the module is 
>already initialized it will return without making anything, if not is 
>initialized. The other way is to check if the module is initialized in each 
>function that's called externally. The last is a good practice and normally 
>isn't slow to add:
>
>XXXX
>{ 
> if (!initialized)
>   initialize();
>}
>
>in the entry points. In this way you don't depend on the order of the link.
Or how about this:
void initialize(void) __attribute__((constructor));

void initialize(void)
{
   initialize_first_piece();
   initialize_second_piece();
   /* ... */
}

Nate Eldredge
eldredge AT ap DOT net

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