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* [Bug middle-end/55873] New: Missed trivial uninitialized use warning
@ 2013-01-04 11:38 steven at gcc dot gnu.org
2013-01-04 11:46 ` [Bug middle-end/55873] " rguenth at gcc dot gnu.org
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: steven at gcc dot gnu.org @ 2013-01-04 11:38 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55873
Bug #: 55873
Summary: Missed trivial uninitialized use warning
Classification: Unclassified
Product: gcc
Version: 4.8.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
AssignedTo: unassigned@gcc.gnu.org
ReportedBy: steven@gcc.gnu.org
extern int foo (int);
int foo (int c)
{
int res;
if (c)
res = 0;
return res;
}
res may be used uninitialized if c==0, but the function is "optimized" to
"return 0" before the uninit1 warning pass runs.
^ permalink raw reply [flat|nested] 4+ messages in thread* [Bug middle-end/55873] Missed trivial uninitialized use warning 2013-01-04 11:38 [Bug middle-end/55873] New: Missed trivial uninitialized use warning steven at gcc dot gnu.org @ 2013-01-04 11:46 ` rguenth at gcc dot gnu.org 2013-01-05 12:11 ` manu at gcc dot gnu.org 2013-01-05 12:16 ` manu at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: rguenth at gcc dot gnu.org @ 2013-01-04 11:46 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55873 Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution| |WONTFIX --- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> 2013-01-04 11:46:06 UTC --- It's conditionally uninitialized and thus only warned in late uninit pass. This is a known issue of optimistic constant propagation. Duplicate of PRxyz. Never going to be fixed. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug middle-end/55873] Missed trivial uninitialized use warning 2013-01-04 11:38 [Bug middle-end/55873] New: Missed trivial uninitialized use warning steven at gcc dot gnu.org 2013-01-04 11:46 ` [Bug middle-end/55873] " rguenth at gcc dot gnu.org @ 2013-01-05 12:11 ` manu at gcc dot gnu.org 2013-01-05 12:16 ` manu at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: manu at gcc dot gnu.org @ 2013-01-05 12:11 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55873 Manuel López-Ibáñez <manu at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |manu at gcc dot gnu.org --- Comment #2 from Manuel López-Ibáñez <manu at gcc dot gnu.org> 2013-01-05 12:10:56 UTC --- PR18501, the most frequently reported Wuninitialized bug. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug middle-end/55873] Missed trivial uninitialized use warning 2013-01-04 11:38 [Bug middle-end/55873] New: Missed trivial uninitialized use warning steven at gcc dot gnu.org 2013-01-04 11:46 ` [Bug middle-end/55873] " rguenth at gcc dot gnu.org 2013-01-05 12:11 ` manu at gcc dot gnu.org @ 2013-01-05 12:16 ` manu at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: manu at gcc dot gnu.org @ 2013-01-05 12:16 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55873 --- Comment #3 from Manuel López-Ibáñez <manu at gcc dot gnu.org> 2013-01-05 12:15:35 UTC --- PR18501, the most frequently reported Wuninitialized bug. Of course, it is possible to fix it. Clang does warn: pr18501.c:5:7: warning: variable 'res' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized] if (c) ^ pr18501.c:7:10: note: uninitialized use occurs here return res; ^~~ pr18501.c:5:3: note: remove the 'if' if its condition is always true if (c) ^~~~~~ pr18501.c:4:10: note: initialize the variable 'res' to silence this warning int res; ^ = 0 1 warning generated. It is just that it probably needs some serious amount of work. ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2013-01-05 12:16 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2013-01-04 11:38 [Bug middle-end/55873] New: Missed trivial uninitialized use warning steven at gcc dot gnu.org 2013-01-04 11:46 ` [Bug middle-end/55873] " rguenth at gcc dot gnu.org 2013-01-05 12:11 ` manu at gcc dot gnu.org 2013-01-05 12:16 ` manu at gcc dot gnu.org
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