* ADA compiler and ELF object format
@ 2001-11-26 13:50 Sandro Binetti
2001-11-26 19:52 ` Ted Dennison
2001-11-27 3:57 ` Robert Dewar
0 siblings, 2 replies; 4+ messages in thread
From: Sandro Binetti @ 2001-11-26 13:50 UTC (permalink / raw)
Hi everybody.
How coul'd I move the .data section into the .bss section of an ELF
object?
I've seen that leaving uninitialized the variables inside my ADA
program does move the object allocation from the .data section into
the .bss one. Is there another way to achieve the same result?
Ah, I'm using a GHS Ada Multi Compiler for Sparc.
Tnx, Sandro.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: ADA compiler and ELF object format
2001-11-26 13:50 ADA compiler and ELF object format Sandro Binetti
@ 2001-11-26 19:52 ` Ted Dennison
2001-11-27 1:14 ` Steven Deller
2001-11-27 3:57 ` Robert Dewar
1 sibling, 1 reply; 4+ messages in thread
From: Ted Dennison @ 2001-11-26 19:52 UTC (permalink / raw)
In article <877f1a1d.0111260550.182cd41d@posting.google.com>, Sandro Binetti
says...
>How coul'd I move the .data section into the .bss section of an ELF
>object?
>I've seen that leaving uninitialized the variables inside my ADA
>program does move the object allocation from the .data section into
>the .bss one. Is there another way to achieve the same result?
>
>Ah, I'm using a GHS Ada Multi Compiler for Sparc.
You'd be pretty lucky to find someone who has messed around a lot with object
file formats for that particular compiler hanging out here (but it could
happen).
You may have better luck asking Green Hills support.
---
T.E.D. homepage - http://www.telepath.com/dennison/Ted/TED.html
No trees were killed in the sending of this message.
However a large number of electrons were terribly inconvenienced.
^ permalink raw reply [flat|nested] 4+ messages in thread
* RE: ADA compiler and ELF object format
2001-11-26 19:52 ` Ted Dennison
@ 2001-11-27 1:14 ` Steven Deller
0 siblings, 0 replies; 4+ messages in thread
From: Steven Deller @ 2001-11-27 1:14 UTC (permalink / raw)
To: comp.lang.ada
In ELF (and COFF and a.out formats), .bss is "uninitialized" data and .data
is "initialized data". Period. In BSS, there is no stored value in the
object file, just recognition of "space needed" with any symbols for the
structures pointing to that space. With DATA, there is a value on the disk
that must be loaded into memory.
You don't get to move items back and forth between these. Data are in their
respective locations because the data either does, or does not, have an
initial value.
As you noted, eliminating an initial value moves an item from .data to .bss.
No surprise.
FYI, BSS per http://mist.npl.washington.edu/faq/unix-FAQ-1-3.html
bss = "Block Started by Symbol"
Dennis Ritchie says:
Actually the acronym (in the sense we took it up; it may
have other credible etymologies) is "Block Started by
Symbol." It was a pseudo-op in FAP (Fortran Assembly [-er?]
Program), an assembler for the IBM 704-709-7090-7094
machines. It defined its label and set aside space for a
given number of words. There was another pseudo-op, BES,
"Block Ended by Symbol" that did the same except that the
label was defined by the last assigned word + 1. (On these
machines Fortran arrays were stored backwards in storage
and were 1-origin.)
The usage is reasonably appropriate, because just as with
standard Unix loaders, the space assigned didn't have to be
punched literally into the object deck but was represented
by a count somewhere.
Regards,
Steve
"Then, after a second or so, nothing continued to happen."
Steven Deller Smooth Sailing LLC
410 757 6924 deller@smsail.com
> -----Original Message-----
> From: comp.lang.ada-admin@ada.eu.org
> [mailto:comp.lang.ada-admin@ada.eu.org]On Behalf Of Ted Dennison
> Sent: Monday, November 26, 2001 2:53 PM
> To: comp.lang.ada@ada.eu.org
> Subject: Re: ADA compiler and ELF object format
>
>
> In article <877f1a1d.0111260550.182cd41d@posting.google.com>,
> Sandro Binetti
> says...
> >How coul'd I move the .data section into the .bss section of an ELF
> >object?
> >I've seen that leaving uninitialized the variables inside my ADA
> >program does move the object allocation from the .data section into
> >the .bss one. Is there another way to achieve the same result?
> >
> >Ah, I'm using a GHS Ada Multi Compiler for Sparc.
>
> You'd be pretty lucky to find someone who has messed around a
> lot with object
> file formats for that particular compiler hanging out here
> (but it could
> happen).
>
> You may have better luck asking Green Hills support.
>
> ---
> T.E.D. homepage - http://www.telepath.com/dennison/Ted/TED.html
>
> No trees were killed in the sending of this message.
> However a large number of electrons were terribly inconvenienced.
> _______________________________________________
> comp.lang.ada mailing list
> comp.lang.ada@ada.eu.org
> http://ada.eu.org/mailman/listinfo/comp.lang.ada
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: ADA compiler and ELF object format
2001-11-26 13:50 ADA compiler and ELF object format Sandro Binetti
2001-11-26 19:52 ` Ted Dennison
@ 2001-11-27 3:57 ` Robert Dewar
1 sibling, 0 replies; 4+ messages in thread
From: Robert Dewar @ 2001-11-27 3:57 UTC (permalink / raw)
sandrobinetti@yahoo.com (Sandro Binetti) wrote in message news:<877f1a1d.0111260550.182cd41d@posting.google.com>...
> Hi everybody.
>
> How coul'd I move the .data section into the .bss section of an ELF
> object?
> I've seen that leaving uninitialized the variables inside my ADA
> program does move the object allocation from the .data section into
> the .bss one. Is there another way to achieve the same result?
>
> Ah, I'm using a GHS Ada Multi Compiler for Sparc.
>
> Tnx, Sandro.
Surely this is the kind of question that you should
ask your vendor to sort out for you, since the answer
is highly compiler specific.
^ permalink raw reply [flat|nested] 4+ messages in thread
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2001-11-26 19:52 ` Ted Dennison
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