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| From | bert <bert.hutchings@btinternet.com> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: Multi-instructions macro and compiler warning |
| Date | 2011-10-16 05:33 -0700 |
| Organization | http://groups.google.com |
| Message-ID | <13142568.4443.1318768394694.JavaMail.geo-discussion-forums@vbat14> (permalink) |
| References | <j7e002$64g$1@nnrp.ngi.it> <9fvfilF3u9U2@mid.individual.net> <j7e1qm$7te$1@nnrp.ngi.it> |
On Sunday, October 16, 2011 8:41:10 AM UTC+1, pozz wrote:
> Il 16/10/2011 09:31, Ian Collins ha scritto:
> > On 10/16/11 08:09 PM, pozz wrote:
> >> I'm trying to increase the warning level during compilation. My goal is
> >> to reach the maximum warning level without any warning message after
> >> compilation. I think this is a Good Thing to do when programming.
> >>
> >> After changing warning level from 4 to 5, I received many warning
> >> messages of the type
> >>
> >> W1207C: conditional expression is constant: dowhile
> >>
> >> Those messages refer to multi-instructions macros defined as below:
> >>
> >> #define MACRO(a, b) do { foo(a); bar(b); } while(0)
> >>
> >> Many times I read to use the trick do/while(0) to write
> >> multi-instruction macros to avoid other problems during compilation. In
> >> this way, I can use MACRO() at any point where I could use a normal
> >> function.
> >>
> >> How can I avoid the warning message W1207C? I'm using an embedded
> >> microcontroller C compiler from Fujitsu, named Softune.
> >
> > Use a function. Any decent compiler will inline something that trivial.
>
> I have *many* macros of the same type (do/while(0)) in my projects,
> sparsed over source and include files. The trivial MACRO() macro in my
> original post is just an example to describe my approach for
> multi-instructions macros.
>
> Should I change a macro for a function just to avoid a warning from
> compiler? It doesn't make sense to me.
I think he meant an in-lineable function
something like:
int never(void)
{ return 0;
}
then use while(never()); instead of while(0);
--
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Multi-instructions macro and compiler warning pozz <pozzugno@gmail.com> - 2011-10-16 09:09 +0200
Re: Multi-instructions macro and compiler warning Ian Collins <ian-news@hotmail.com> - 2011-10-16 20:31 +1300
Re: Multi-instructions macro and compiler warning pozz <pozzugno@gmail.com> - 2011-10-16 09:41 +0200
Re: Multi-instructions macro and compiler warning Ian Collins <ian-news@hotmail.com> - 2011-10-16 20:49 +1300
Re: Multi-instructions macro and compiler warning pozz <pozzugno@gmail.com> - 2011-10-16 10:16 +0200
Re: Multi-instructions macro and compiler warning Ian Collins <ian-news@hotmail.com> - 2011-10-16 23:09 +1300
Re: Multi-instructions macro and compiler warning pozz <pozzugno@gmail.com> - 2011-10-17 02:37 -0700
Re: Multi-instructions macro and compiler warning Ian Collins <ian-news@hotmail.com> - 2011-10-17 23:04 +1300
Re: Multi-instructions macro and compiler warning Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-10-17 11:06 +0100
Re: Multi-instructions macro and compiler warning pozz <pozzugno@gmail.com> - 2011-10-17 03:23 -0700
Re: Multi-instructions macro and compiler warning Keith Thompson <kst-u@mib.org> - 2011-10-17 12:30 -0700
Re: Multi-instructions macro and compiler warning "BartC" <bc@freeuk.com> - 2011-10-16 12:47 +0100
Re: Multi-instructions macro and compiler warning Jorgen Grahn <grahn+nntp@snipabacken.se> - 2011-10-16 22:16 +0000
Re: Multi-instructions macro and compiler warning pozz <pozzugno@gmail.com> - 2011-10-17 02:42 -0700
Re: Multi-instructions macro and compiler warning "BartC" <bc@freeuk.com> - 2011-10-17 13:10 +0100
Re: Multi-instructions macro and compiler warning bert <bert.hutchings@btinternet.com> - 2011-10-16 05:33 -0700
Re: Multi-instructions macro and compiler warning Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-10-16 09:02 -0400
Re: Multi-instructions macro and compiler warning "christian.bau" <christian.bau@cbau.wanadoo.co.uk> - 2011-10-16 07:40 -0700
Re: Multi-instructions macro and compiler warning ImpalerCore <jadill33@gmail.com> - 2011-10-17 08:07 -0700
Re: Multi-instructions macro and compiler warning "christian.bau" <christian.bau@cbau.wanadoo.co.uk> - 2011-10-17 09:25 -0700
Re: Multi-instructions macro and compiler warning James Kuyper <jameskuyper@verizon.net> - 2011-10-17 12:58 -0400
Re: Multi-instructions macro and compiler warning Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-10-18 07:43 -0400
Re: Multi-instructions macro and compiler warning Keith Thompson <kst-u@mib.org> - 2011-10-18 11:52 -0700
Re: Multi-instructions macro and compiler warning ImpalerCore <jadill33@gmail.com> - 2011-10-17 10:41 -0700
Re: Multi-instructions macro and compiler warning Jean-Christophe <5.d@free.fr> - 2011-10-16 10:02 -0700
Re: Multi-instructions macro and compiler warning Kleuskes & Moos <kleuske@somewhere.else.net> - 2011-10-16 17:44 +0000
Re: Multi-instructions macro and compiler warning Keith Thompson <kst-u@mib.org> - 2011-10-16 13:49 -0700
Re: Multi-instructions macro and compiler warning Ian Collins <ian-news@hotmail.com> - 2011-10-17 10:00 +1300
Re: Multi-instructions macro and compiler warning Kenneth Brody <kenbrody@spamcop.net> - 2011-10-17 12:50 -0400
Re: Multi-instructions macro and compiler warning "Morris Keesan" <mkeesan@post.harvard.edu> - 2011-10-17 14:50 -0400
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