public inbox for gcc-bugs@sourceware.org help / color / mirror / Atom feed
* [Bug tree-optimization/102192] New: Curious '-O2'-only '-Wmaybe-uninitialized' diagnostics for 'libgomp.oacc-fortran/routine-10.f90' @ 2021-09-03 14:59 tschwinge at gcc dot gnu.org 2021-10-06 16:44 ` [Bug tree-optimization/102192] " msebor at gcc dot gnu.org 2022-01-13 10:52 ` cvs-commit at gcc dot gnu.org 0 siblings, 2 replies; 3+ messages in thread From: tschwinge at gcc dot gnu.org @ 2021-09-03 14:59 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102192 Bug ID: 102192 Summary: Curious '-O2'-only '-Wmaybe-uninitialized' diagnostics for 'libgomp.oacc-fortran/routine-10.f90' Product: gcc Version: 12.0 Status: UNCONFIRMED Keywords: diagnostic Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: tschwinge at gcc dot gnu.org CC: burnus at gcc dot gnu.org Blocks: 24639 Target Milestone: --- The 'libgomp.oacc-fortran/routine-10.f90' test case as originally added in commit 12df77ab6df4b91d4770240bcc4ab443e4bb18b9 shows curious '-Wmaybe-uninitialized' diagnostics. Now, of course this is '-Wmaybe-uninitialized', so may easily be dismissed "don't care", but maybe there's something to be improved here? For standard host compilation (no '-fopenacc'), but only with '-O2', we get diagnosed: libgomp.oacc-fortran/routine-10.f90:28:21: Warning: ‘c’ may be used uninitialized in this function [-Wmaybe-uninitialized] libgomp.oacc-fortran/routine-10.f90:21:50: note: ‘c’ was declared here libgomp.oacc-fortran/routine-10.f90:46:30: Warning: ‘c’ may be used uninitialized in this function [-Wmaybe-uninitialized] libgomp.oacc-fortran/routine-10.f90:21:50: note: ‘c’ was declared here Not seeing this with any other '-O[...]' level, and also goes away with '-O2 -fno-inline', for example. Have not quickly been able to reproduce with '-O3' plus various '-fno-[...]. Referenced Bugs: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=24639 [Bug 24639] [meta-bug] bug to track all Wuninitialized issues ^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug tree-optimization/102192] Curious '-O2'-only '-Wmaybe-uninitialized' diagnostics for 'libgomp.oacc-fortran/routine-10.f90' 2021-09-03 14:59 [Bug tree-optimization/102192] New: Curious '-O2'-only '-Wmaybe-uninitialized' diagnostics for 'libgomp.oacc-fortran/routine-10.f90' tschwinge at gcc dot gnu.org @ 2021-10-06 16:44 ` msebor at gcc dot gnu.org 2022-01-13 10:52 ` cvs-commit at gcc dot gnu.org 1 sibling, 0 replies; 3+ messages in thread From: msebor at gcc dot gnu.org @ 2021-10-06 16:44 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102192 Martin Sebor <msebor at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |WAITING Ever confirmed|0 |1 CC| |msebor at gcc dot gnu.org Last reconfirmed| |2021-10-06 --- Comment #1 from Martin Sebor <msebor at gcc dot gnu.org> --- There are lots of reports about -Wmaybe-uninitialized triggering when it's not expected to. Some are bugs/limitations in the warning but others are inherent in the IL the warning works with and can't be avoided given its design. Without a small test case to easily reproduce the suspected problem, given the large number of reports with test cases, it's unlikely that anyone will go try to extract one from a historical Git revision of a test, especially one written in FORTRAN and involving complex control flow, to determine were this one falls. I would suggest to include the test in the bug report, along with the output (as we ask users to do). Better yet would be reducing the suspected false positive to a smaller test case, and ideally converting it to C. ^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug tree-optimization/102192] Curious '-O2'-only '-Wmaybe-uninitialized' diagnostics for 'libgomp.oacc-fortran/routine-10.f90' 2021-09-03 14:59 [Bug tree-optimization/102192] New: Curious '-O2'-only '-Wmaybe-uninitialized' diagnostics for 'libgomp.oacc-fortran/routine-10.f90' tschwinge at gcc dot gnu.org 2021-10-06 16:44 ` [Bug tree-optimization/102192] " msebor at gcc dot gnu.org @ 2022-01-13 10:52 ` cvs-commit at gcc dot gnu.org 1 sibling, 0 replies; 3+ messages in thread From: cvs-commit at gcc dot gnu.org @ 2022-01-13 10:52 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102192 --- Comment #2 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Thomas Schwinge <tschwinge@gcc.gnu.org>: https://gcc.gnu.org/g:2edbcaed95b8d8cbb05a6af486179db0da6e3245 commit r12-6547-g2edbcaed95b8d8cbb05a6af486179db0da6e3245 Author: Thomas Schwinge <thomas@codesourcery.com> Date: Thu Aug 26 16:55:21 2021 +0200 Document current '-Wuninitialized' diagnostics for 'libgomp.oacc-fortran/routine-10.f90' [PR102192] libgomp/ PR tree-optimization/102192 * testsuite/libgomp.oacc-fortran/routine-10.f90: Document current '-Wuninitialized' diagnostics. ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2022-01-13 10:52 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-09-03 14:59 [Bug tree-optimization/102192] New: Curious '-O2'-only '-Wmaybe-uninitialized' diagnostics for 'libgomp.oacc-fortran/routine-10.f90' tschwinge at gcc dot gnu.org 2021-10-06 16:44 ` [Bug tree-optimization/102192] " msebor at gcc dot gnu.org 2022-01-13 10:52 ` cvs-commit at gcc dot gnu.org
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).