Re: GNAT on WinXP: System.OS_Lib.Spawn raises Program_Error

["Ed Falis" <falis@verizon.net>]

On Sun, 03 May 2009 20:22:14 -0400, anon <anon@anon.org> wrote:
> General comments should be taken with a gain of salt.  If you check,  
> most of
> the GNAT packages and programs, you will see 100s of comments that are  
> not
> valid or useful. Like, "Is this correct" or "need comment here". Then  
> other
> places where comments could be useful there is only code.

None of us are perfect, eh?  There is an ongoing process of improving  
comments.  The one I quoted is not ambiguous.  But you're correct that I  
was wrong about the warning being generated in this case.

>
> What is needed is another documentation file, called may be "GNAT  
> extension
> to Ada 2005 specification", where the documentation would explain the  
> extra
> packages with each package routine, and including the package  
> limitations,
> if any.

It's called the GNAT Reference Manual, which does not document  
System.OS_Lib as part of the GNAT public library.  Generally, it refers to  
the source specifications for details.

>
> The following example show that the "System.OS.LIB" could be set as a
> non-portable internal system file that generates warning and forces a
> programmer to use "GNAT.OS_LIB".  But in Ada 2005 version, Adacore
> decided not too. Which allows the programmer to choose to use
> "GNAT.OS_LIB" (Ada 95 specs) or "System.OS_LIB" (Ada 2005 specs). Just
> like some programmers choose to use "Text_IO" instead of "Ada.Text_IO",
> or "Unchecked_Conversion" instead of "Ada.Unchecked_Conversion".

The unqualified names of the standard library packages are "deprecated"  
but retained for backward compatibility.  As far as System.OS_Lib goes,  
I'll be asking tomorrow why we allow its use without generating a  
warning.  Seems like an oversight to me rather than a decision, but as you  
point out in your example, this lack of a warning appears to be related to  
package renamings.

- Ed