From: Daniel Jacobowitz <drow@mvista.com>
To: Kris Warkentin <kewarken@qnx.com>
Cc: gdb@sources.redhat.com
Subject: Re: long long considered harmful?
Date: Tue, 22 Apr 2003 17:45:00 -0000 [thread overview]
Message-ID: <20030422174522.GA728@nevyn.them.org> (raw)
In-Reply-To: <076701c308f6$2f017eb0$0202040a@catdog>
On Tue, Apr 22, 2003 at 01:39:53PM -0400, Kris Warkentin wrote:
> Below is a clipping from our debug.h header which defines the register
> structures for QNX Neutrino. I've been in conversation with Mark Kettenis
> about our gdb submission and it looks like portability issues in this header
> are one of the few remaining stumbling blocks, at least from his
> perspective. I guess that conceivably some older systems might not be able
> to deal with a 64 bit int type. The question I want to ask is, "how do I
> deal with this in a portable way?"
>
> I don't believe that any of these structures are ever manipulated in any way
> other than to read/write bytes of data into and out of them. Would it be
> best just to define any long long members as arrays of char? It doesn't
> seem very pretty but it would certainly do the trick.
>
> ie. "char u64[8]" instead of "long long u64" is fine but "char gpr_hi[32 *
> 8]" instead of "long long gpr_hi[32]" seems a bit nasty.
>
> comments?
Several things come to my eye as problems here:
> >>>>>>>>>>>>>debug.h clip<<<<<<<<<<<<<<<<<<<<<
> typedef union
> {
> unsigned long long u64;
> double f;
> } mipsfloat;
This is a target entity isn't it? You've got no business using
"double" for a target float. Use the gdb type mechanism instead.
> typedef struct mips_cpu_registers
> {
> unsigned regs[74];
> unsigned long long regs_alignment;
> } MIPS_CPU_REGISTERS;
What's the purpose of the alignment entry? I doubt it does what you
want it to.
> #ifdef __BIGREGS__
Eh?
> typedef union
> {
> unsigned long long u64[2];
> unsigned u32[4];
> unsigned char u8[16];
> float f32[4];
> } ppcvmx;
As above.
I recommend something like 'typedef char qnx_reg64[8];'; then you can
still say 'qnx_reg64 gpr[32]' and get the right result.
--
Daniel Jacobowitz
MontaVista Software Debian GNU/Linux Developer
next prev parent reply other threads:[~2003-04-22 17:45 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-04-22 17:39 Kris Warkentin
2003-04-22 17:45 ` Daniel Jacobowitz [this message]
2003-04-22 18:08 ` Kris Warkentin
2003-04-22 18:21 ` Daniel Jacobowitz
2003-04-22 18:41 ` Kris Warkentin
2003-04-22 19:31 ` Daniel Jacobowitz
2003-04-22 19:12 ` Kris Warkentin
2003-04-22 19:25 ` Kris Warkentin
2003-04-22 19:30 ` Daniel Jacobowitz
2003-04-23 13:39 ` Kris Warkentin
2003-04-23 21:17 ` Daniel Jacobowitz
2003-04-23 21:23 ` Kris Warkentin
2003-04-23 21:44 ` Kris Warkentin
2003-04-23 21:47 ` Daniel Jacobowitz
2003-04-23 22:09 ` Kris Warkentin
2003-04-23 22:11 ` Daniel Jacobowitz
2003-04-23 22:17 ` Kris Warkentin
2003-04-24 21:05 ` Andrew Cagney
2003-04-24 23:51 ` Kris Warkentin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20030422174522.GA728@nevyn.them.org \
--to=drow@mvista.com \
--cc=gdb@sources.redhat.com \
--cc=kewarken@qnx.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).