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From: "eggert at cs dot ucla.edu" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/101912] New: -Wmaybe-uninitialized false alarm in tzdb localtime.c Date: Sat, 14 Aug 2021 19:27:35 +0000 [thread overview] Message-ID: <bug-101912-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101912 Bug ID: 101912 Summary: -Wmaybe-uninitialized false alarm in tzdb localtime.c Product: gcc Version: 11.2.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: eggert at cs dot ucla.edu Target Milestone: --- Created attachment 51303 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=51303&action=edit -Wuninitialized false alarm This is a simplified version of a problem I found while compiling tzdb's localtime.c with gcc (GCC) 11.2.1 20210728 (Red Hat 11.2.1-1) on x86-64. Compile the attached program w.i with: gcc -Wmaybe-uninitialized -O2 -S w.i The output is: w.i: In function ‘tzloadbody’: w.i:17:27: warning: ‘prevcorr’ may be used uninitialized in this function [-Wmaybe-uninitialized] 16 | : (corr == prevcorr | ~~~~~~~~~~~~~~~~~ 17 | || corr == prevcorr - 1))))) | ^~~~~~~~~~~~~~~~~~~~~~~~ This is a false alarm, since the underlined code is executed only when leapcnt is nonzero, and leapcnt is set to a nonzero value only after prevcorr is initialized.
next reply other threads:[~2021-08-14 19:27 UTC|newest] Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-08-14 19:27 eggert at cs dot ucla.edu [this message] 2021-08-16 17:07 ` [Bug tree-optimization/101912] " msebor at gcc dot gnu.org 2021-11-30 15:41 ` aldyh at gcc dot gnu.org 2021-11-30 16:02 ` aldyh at gcc dot gnu.org 2021-11-30 16:47 ` eggert at cs dot ucla.edu 2021-12-01 7:49 ` rguenther at suse dot de 2021-12-01 16:22 ` aldyh at gcc dot gnu.org 2022-12-25 0:06 ` pinskia at gcc dot gnu.org 2022-12-27 12:26 ` marxin at gcc dot gnu.org 2023-01-09 10:02 ` rguenth at gcc dot gnu.org 2023-01-09 11:19 ` cvs-commit at gcc dot gnu.org 2023-01-09 11:20 ` rguenth at gcc dot gnu.org 2023-04-12 13:30 ` sjames at gcc dot gnu.org 2023-04-12 13:31 ` sjames at gcc dot gnu.org 2023-04-26 6:55 ` rguenth at gcc dot gnu.org 2023-07-04 9:19 ` rguenth at gcc dot gnu.org 2023-07-04 9:19 ` rguenth at gcc dot gnu.org
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