From: Jim Blandy <jimb@red-bean.com>
To: NZG <ngustavson@emacinc.com>
Cc: gdb-patches@sourceware.org,
uClinux development list <uclinux-dev@uclinux.org>
Subject: Re: gdb code review, pointer madness
Date: Mon, 23 Jan 2006 20:51:00 -0000 [thread overview]
Message-ID: <8f2776cb0601231251v253ad0dft98eb2b558531d99@mail.gmail.com> (raw)
In-Reply-To: <200601231438.26040.ngustavson@emacinc.com>
On 1/23/06, NZG <ngustavson@emacinc.com> wrote:
> Specifically this loop doesn't seem to be executing correctly
>
> for (p = startaddr; p < endaddr; ++p)
> retval = (retval << 8) | *p;
>
> In the function call I'm watching,
> endaddr = startaddr+4,
> yet, when I step through the function the loop executes 8 times and overshoots
> the array.
>
> I don't see anything wrong with the code.
> Can anyone else see anything weird in the pointer math below?
I don't think there's anything wrong with the C code. That's a
completely fundamental function in GDB, used everywhere, all the time.
And it's hard for me to believe that both endiannesses aren't being
exercised. If it were broken, we surely would have found out by now.
If the function is behaving as you say, then I'd say your compiler has
miscompiled GDB. Why don't you look through the assembly code for the
function, and see if it's right?
next prev parent reply other threads:[~2006-01-23 20:51 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-01-23 20:39 NZG
2006-01-23 20:48 ` Daniel Jacobowitz
2006-01-23 20:51 ` Jim Blandy [this message]
2006-01-24 17:19 ` NZG
2006-01-24 19:29 ` NZG
2006-01-24 21:27 ` Jim Blandy
2006-01-24 21:58 ` NZG
2006-01-24 22:11 ` Daniel Jacobowitz
2006-01-25 0:01 ` Jim Blandy
2006-01-25 4:41 ` Eli Zaretskii
2006-01-25 4:59 ` Jim Blandy
2006-01-25 5:25 ` Jim Blandy
2006-01-25 17:21 ` Eli Zaretskii
2006-01-25 18:49 ` Jim Blandy
2006-01-25 19:58 ` Eli Zaretskii
2006-01-25 17:15 ` Eli Zaretskii
2006-01-26 16:19 ` NZG
2006-01-26 16:43 ` Daniel Jacobowitz
2006-01-26 19:55 ` frame theory, was " NZG
2006-01-26 19:59 ` Daniel Jacobowitz
2006-01-26 20:17 ` NZG
2006-01-26 20:22 ` Daniel Jacobowitz
2006-01-26 21:21 ` Mark Kettenis
2006-01-26 21:54 ` NZG
2006-01-26 22:40 ` Mark Kettenis
2006-01-26 22:44 ` Daniel Jacobowitz
2006-01-26 23:27 ` remote connection crash, was frame theory NZG
2006-01-26 23:32 ` Daniel Jacobowitz
2006-01-26 23:42 ` Jim Blandy
2006-01-26 23:45 ` Daniel Jacobowitz
2006-01-26 23:57 ` Jim Blandy
2006-01-27 0:04 ` NZG
2006-01-30 17:02 ` 5282 gdb Eclipse MI support, was remote connection crash NZG
2006-01-26 23:47 ` frame theory, was pointer madness Accounts
2006-01-26 23:16 ` Jim Blandy
2006-01-26 23:39 ` Jim Blandy
2006-01-27 7:19 ` Eli Zaretskii
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