Date: Wed, 15 Oct 1997 18:03:35 -0700 (PDT)
Message-Id: <199710160103.SAA04722@adit.ap.net>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
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
Precedence: bulk

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