From: John Love-Jensen <eljay@adobe.com>
To: Claudio Bley <bley@cs.uni-magdeburg.de>,
Florian Weimer <fw@deneb.enyo.de>
Cc: Joshua Nye <josh@boxcarmedia.com>, Steve Dondley <s@dondley.com>,
<gcc-help@gcc.gnu.org>
Subject: Re: Avoiding "assignment from incompatible pointer type" warning
Date: Mon, 21 Oct 2002 06:43:00 -0000 [thread overview]
Message-ID: <B9D96E10.5411%eljay@adobe.com> (raw)
In-Reply-To: <15795.58223.521979.895246@wh2-19.st.uni-magdeburg.de>
Hi Claudio,
> I can't see why. Can you elaborate on that? I mean, casting on the
> machine code level does just nothing - it's just "syntactic sugar" to
> convince the compiler to be quiet. I think casting from one pointer
> type to another does no harm at all. Am I wrong?
You are correct, the casting is fine, insofar as the given code snippet
goes.
I assume the complaint/concern was regarding the (presumed) dereferencing of
the int* p at some later point in the code.
Note: cavalier casting is highly suspect, and prone to be very platform
specific (when it does work as intended). For instance, on Solaris a
misaligned value can cause a bus error. Often the injudicious, cavalier
casting is the culprit.
To do the hex dump as intended, I'd do something like this...
void HexDump(void* ptr, size_t len)
{
unsigned char* p = (unsigned char*)ptr;
while(len--)
{
printf("%02x%c", *p++, len ? ' ' : '\n');
}
}
int main()
{
float g = 3.141592653589793238;
HexDump(&g, sizeof g);
}
...but that's just me. :-)
--Eljay
next prev parent reply other threads:[~2002-10-21 13:43 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-10-13 9:08 Steve Dondley
2002-10-13 9:28 ` Joshua Nye
2002-10-13 9:34 ` Steve Dondley
2002-10-13 15:09 ` Florian Weimer
2002-10-13 15:19 ` Joshua Nye
2002-10-15 11:24 ` Joshua Nye
2002-10-21 3:12 ` Florian Weimer
2002-10-21 4:22 ` Claudio Bley
2002-10-21 4:30 ` Florian Weimer
2002-10-21 6:48 ` Claudio Bley
2002-10-21 4:42 ` Sebastian Huber
2002-10-21 6:43 ` John Love-Jensen [this message]
2002-10-21 6:52 ` Florian Weimer
2002-10-13 13:37 Moore, Mathew L
2002-10-13 15:10 ` Florian Weimer
2002-10-21 6:07 Moore, Mathew L
2002-10-21 7:04 Moore, Mathew L
2002-10-21 7:17 ` Florian Weimer
2002-10-21 7:43 ` John Love-Jensen
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=B9D96E10.5411%eljay@adobe.com \
--to=eljay@adobe.com \
--cc=bley@cs.uni-magdeburg.de \
--cc=fw@deneb.enyo.de \
--cc=gcc-help@gcc.gnu.org \
--cc=josh@boxcarmedia.com \
--cc=s@dondley.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).