Re: Looking for a smart linker for GNAT/DOS

[Gautier.DeMontmollin@maths.unine.ch (Gautier)]

> <<...
> It could avoid the explosion of executables' sizes
> (47k for a ``null'' programme, 97k for a ``hello world'',...)>>

dewar@merv.cs.nyu.edu (Robert Dewar) writes:
 
> Are you sure you are stripping the executables? I find only 24K for
> a null program on OS/2, and that is without a shared library (it would
> of course be MUCH smaller if I used a shared library).
> 
> In any case, I don't think there is much in the way of unused code in
> these programs -- what makes you think there is? GNAT only loads library
> units that are used.

Oh? Not every package found on the HD is linked ? ;-)

>                      There is a certain fundamental overhead of stuff
> that is needed to e.g. setup handling of standard exceptions.
> 
> But I think your 47K sounds like it still has some debugging stuff left in

The 47k programme is compiled without debug option (-g) 
and the exe is stripped. The fact that the DOS version has 47k and the OS/2,
24K, seems normal since with the DOS version all I/O and file handling must
be made through the DPMI interface.

This 47k basis is not annoying but the fact that 100% of each new added
package is linked although a part of it (maybe a few tenth for a graphics
package, a few thousends for a numerics package like LAPACK) is really used.

Here is a test package to illustrate it:

-------------------------------------------------------------------------------
--  Package to test the linker's smartness (unused procedures detection)
--  See P_TstLnk test procedure

package TestLink is
  procedure A; procedure B; procedure C; procedure D;
end;

with Text_IO; use Text_IO;
package body TestLink is
  procedure A is begin Put("Adalbert"); end;   
  procedure B is begin Put("Berthold"); end;
  procedure C is begin Put("Clothilde"); end;
  procedure D is 
    procedure E is begin Put("Ernest"); end;
    procedure F is begin Put("Fabien"); end;
  begin Put("Dagobert"); E; end;
end;

-- Only "Berthold", "Dagobert", "Ernest" strings should appear in P_TSTLNK.EXE
-- "Adalbert", "Clothilde", "Fabien" should not appear.

with TestLink; use TestLink; procedure P_TstLnk is begin B; D; end;
------------------------------------------------------------------------------- 

A Turbo Pascal equivalent of it will have only the used procedures in the .exe

G.