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From: dillon@CORY.BERKELEY.EDU.UUCP
Newsgroups: comp.sys.amiga
Subject: Run-time named library vectors... suggestion for 1.3
Message-ID: <8706060558.AA04607@cory.Berkeley.EDU>
Date: Sat, 6-Jun-87 01:58:08 EDT
Article-I.D.: cory.8706060558.AA04607
Posted: Sat Jun  6 01:58:08 1987
Date-Received: Sun, 7-Jun-87 03:08:50 EDT
Sender: daemon@ucbvax.BERKELEY.EDU
Lines: 37


	Here is a neat little tidbit which came out of an operating
systems project I'm working on:  Named library vectors, initialized on
program startup.  It would make a *GREAT* addition to 1.3 (can somebody
give me Dale's email address?).

	It's really simple.  The executable has a new hunk type which is
basically a table of the names for all unresolved symbols the linker found
when the program got linked.  The loader would then fill in a vector table
with the function vectors specified BY NAME in this hunk type.

	Thus, you no longer have static offsets, or even have to deal with
specific libraries, and your programs become binary-portable to new versions
of the OS without lifting a finger or even re-linking.  As an added plus,
the loader can complait and abort the load if any of the unresolved symbols
is actually unresolved... doesn't exist in a library.

	The unresolved symbols would apply only to unresolved function calls.
Of course, you would provide EXEC calls to add/delete functions to this new
type of library where the vectors are named.

	* making stdio and other routines run-time libraries becomes trivial

	* executables are even SMALLER

	* You needn't link with large static libraries... or any at all.

	* programs are completely compatible between OS versions,
	  especially if this new huck has an "OS version expected" field.

	* by providing an interface to the original library types via this
	  new scheme, you would simply relink existing object with a 
	  link-time library which *doesn't* contain the library routines to
	  make it work with the new libraries (assuming you have a new linker
	  which supports the new hunk type).

					-Matt