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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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