* Re: [9fans] 8c funny
@ 2005-05-26 17:10 Brantley Coile
2005-05-26 17:16 ` Russ Cox
2005-05-26 17:18 ` Bruce Ellis
0 siblings, 2 replies; 8+ messages in thread
From: Brantley Coile @ 2005-05-26 17:10 UTC (permalink / raw)
To: 9fans
term% 8c -FVw busted.c
warning: busted.c:5 used and not set: b
term% cat busted.c
#include <u.h>
#include <libc.h>
void
main(void)
{
vlong a;
int b;
if (a == 0)
exits(nil);
if (b == 0)
exits(nil);
exits(nil);
}
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [9fans] 8c funny
2005-05-26 17:10 [9fans] 8c funny Brantley Coile
@ 2005-05-26 17:16 ` Russ Cox
2005-05-26 17:18 ` Bruce Ellis
1 sibling, 0 replies; 8+ messages in thread
From: Russ Cox @ 2005-05-26 17:16 UTC (permalink / raw)
To: Fans of the OS Plan 9 from Bell Labs
the real problem is that the compiler doesn't
do used and not set on vlongs, because they
were originally treated a lot more like structures
than scalars.
russ
On 5/26/05, Brantley Coile <brantley@coraid.com> wrote:
> term% 8c -FVw busted.c
> warning: busted.c:5 used and not set: b
> term% cat busted.c
> #include <u.h>
> #include <libc.h>
>
> void
> main(void)
> {
> vlong a;
>
> int b;
>
> if (a == 0)
> exits(nil);
> if (b == 0)
> exits(nil);
> exits(nil);
> }
>
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [9fans] 8c funny
2005-05-26 17:10 [9fans] 8c funny Brantley Coile
2005-05-26 17:16 ` Russ Cox
@ 2005-05-26 17:18 ` Bruce Ellis
2005-05-26 18:23 ` Charles Forsyth
1 sibling, 1 reply; 8+ messages in thread
From: Bruce Ellis @ 2005-05-26 17:18 UTC (permalink / raw)
To: Fans of the OS Plan 9 from Bell Labs
more confusion. vlongs aren't tracked for these warnings,
just as structs/unions aren't. internally they are treated
much like composites (e.g. they end up at sugen()).
perhaps this should be fixed - it's not too hard.
still confused? well i need some more coffee.
brucee
On 5/27/05, Brantley Coile <brantley@coraid.com> wrote:
> term% 8c -FVw busted.c
> warning: busted.c:5 used and not set: b
> term% cat busted.c
> #include <u.h>
> #include <libc.h>
>
> void
> main(void)
> {
> vlong a;
>
> int b;
>
> if (a == 0)
> exits(nil);
> if (b == 0)
> exits(nil);
> exits(nil);
> }
>
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [9fans] 8c funny
2005-05-26 17:18 ` Bruce Ellis
@ 2005-05-26 18:23 ` Charles Forsyth
0 siblings, 0 replies; 8+ messages in thread
From: Charles Forsyth @ 2005-05-26 18:23 UTC (permalink / raw)
To: 9fans
% 7c -wFV busted.c
warning: busted.c:5 used and not set: a b
it works on alpha and amd64, because in some ways
the set/used is a side-effect of working out when to
put things in registers (or not), and with 64-bit registers,
typev[et] is explicitly allowed (ie, no funny punning), and
ça marche.
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [9fans] 8c funny
2005-05-26 18:44 Ben Huntsman
@ 2005-05-26 18:55 ` jmk
0 siblings, 0 replies; 8+ messages in thread
From: jmk @ 2005-05-26 18:55 UTC (permalink / raw)
To: 9fans
We're still shaking the bugs out.
On Thu May 26 14:45:10 EDT 2005, BHuntsman@mail2.cu-portland.edu wrote:
> >it works on alpha and amd64...
>
> Really stupid question-
> we have an amd64 compiler??
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [9fans] 8c funny
@ 2005-05-26 18:44 Ben Huntsman
2005-05-26 18:55 ` jmk
0 siblings, 1 reply; 8+ messages in thread
From: Ben Huntsman @ 2005-05-26 18:44 UTC (permalink / raw)
To: Fans of the OS Plan 9 from Bell Labs
>it works on alpha and amd64...
Really stupid question-
we have an amd64 compiler??
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [9fans] 8c funny
2005-05-26 16:52 Brantley Coile
@ 2005-05-26 17:02 ` Bruce Ellis
0 siblings, 0 replies; 8+ messages in thread
From: Bruce Ellis @ 2005-05-26 17:02 UTC (permalink / raw)
To: Fans of the OS Plan 9 from Bell Labs
yes, it's "only one prize per child". if cc finds an error (or warning)
in an expression it generally bails on that item - avoiding the
"cascade of errors" from a simple typo. sometimes it can be
annoying (fix "b" in this case and next compile it will complain
about "a") but usually it saves investigating non-errors.
brucee
On 5/27/05, Brantley Coile <brantley@coraid.com> wrote:
> Any one seen this before?
>
> term% cat busted.c
> #include <u.h>
> #include <libc.h>
>
> void
> main(void)
> {
> vlong a;
> int b;
>
> if (a == b)
> exits(nil);
> exits(nil);
> }
> term% 8c -FVw busted.c
> warning: busted.c:5 used and not set: b
> term%
>
> Note that a doesn't get tagged as used and not set.
>
>
> Brantley
^ permalink raw reply [flat|nested] 8+ messages in thread
* [9fans] 8c funny
@ 2005-05-26 16:52 Brantley Coile
2005-05-26 17:02 ` Bruce Ellis
0 siblings, 1 reply; 8+ messages in thread
From: Brantley Coile @ 2005-05-26 16:52 UTC (permalink / raw)
To: 9fans
Any one seen this before?
term% cat busted.c
#include <u.h>
#include <libc.h>
void
main(void)
{
vlong a;
int b;
if (a == b)
exits(nil);
exits(nil);
}
term% 8c -FVw busted.c
warning: busted.c:5 used and not set: b
term%
Note that a doesn't get tagged as used and not set.
Brantley
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2005-05-26 18:55 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2005-05-26 17:10 [9fans] 8c funny Brantley Coile
2005-05-26 17:16 ` Russ Cox
2005-05-26 17:18 ` Bruce Ellis
2005-05-26 18:23 ` Charles Forsyth
-- strict thread matches above, loose matches on Subject: below --
2005-05-26 18:44 Ben Huntsman
2005-05-26 18:55 ` jmk
2005-05-26 16:52 Brantley Coile
2005-05-26 17:02 ` Bruce Ellis
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