From: Andreas Schwab <schwab@issan.informatik.uni-dortmund.de>
To: Alan Modra <alan@spri.levels.unisa.edu.au>
Cc: law@cygnus.com, gcc2@cygnus.com, egcs@cygnus.com, gas2@cygnus.com
Subject: Re: ASM_COMMENT_START and gas divide operator
Date: Thu, 07 May 1998 02:39:00 -0000 [thread overview]
Message-ID: <vyzhg32bet4.fsf@issan.informatik.uni-dortmund.de> (raw)
In-Reply-To: <Pine.LNX.3.96.980507185035.16449A-100000@mullet.Levels.UniSA.Edu.Au>
Alan Modra <alan@spri.levels.unisa.edu.au> writes:
|> On 7 May 1998, Andreas Schwab wrote:
|>> Jeffrey A Law <law@cygnus.com> writes:
|>>
|>> |> In message <Pine.LNX.3.96.980501124359.28262A-100000@mullet.Levels.UniSA.Edu.ou write:
|>> |> > There is a problem with using "/" to start comments, such as those
|>> |> > emitted by gcc's -fverbose-asm. If gas needs to support "/" meaning
|>> |> > the start of a comment anywhere on a line, then the gas division
|>> |> > operator is killed, sometimes silently. For instance:
|>> |> > asm("pushl $FOO/2")
|>> |> > is treated as if the programmer wrote
|>> |> > asm("pushl $FOO")
|>> |> >
|>> |> > Of course, this is only a problem with hand-coded assembly, but it
|>> |> > would be nice to fix gas and gcc. At least on linux, where the only
|>> |> > assembler used with gcc is gas, we should be able to make the
|>> |> > following change without causing too many problems.
|>> |> >
|>> |> > * config/linux.h (ASM_COMMENT_START): Define as "#"
|>> |> > * config/linux-aout.h (ASM_COMMENT_START): Likewise
|>> |> Thanks. I've installed this into egcs.
|>>
|>> This is wrong, it breaks m68k-linux, and perhaps all other non-intel linux
|>> port. It must be moved to config/i386/linux.h. There is no such thing as
|>> a universal comment character.
|> OK, you're right. Just as well I said "without causing too many
|> problems" rather than "no problems" :-) What about ASM_APP_ON and
|> ASM_APP_OFF defined on the next few lines down? Do these really
|> belong in config/i386/linux.h too?
No, these are correct. There are two types of comments, one that start on
column 1 and the other that do not. ASM_APP_* are only written at the
start of the line, and here # is used as comment universally. For inline
comments every port has different conventions. For example, on m68k the #
is used to denote immediate operands, thus it cannot start a comment.
--
Andreas Schwab "And now for something
schwab@issan.informatik.uni-dortmund.de completely different"
schwab@gnu.org
next prev parent reply other threads:[~1998-05-07 2:39 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
1998-04-30 22:29 Alan Modra
1998-05-06 18:34 ` Jeffrey A Law
1998-05-07 1:53 ` Andreas Schwab
1998-05-07 3:59 ` Alan Modra
1998-05-07 2:39 ` Andreas Schwab [this message]
1998-05-14 0:35 ` Martynas Kunigelis
1998-05-14 9:37 ` Jeffrey A Law
1998-05-14 10:17 ` Craig Burley
1998-05-14 13:08 ` Jeffrey A Law
1998-05-14 15:07 ` Craig Burley
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