https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102801
Bug ID: 102801
Summary: Incorrect -Wmaybe-uninitialized warning/interation for
a std::optional only when a nested struct is also
present.
Product: gcc
Version: 11.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: calin.culianu at bitcoincashnode dot org
Target Milestone: ---
Created attachment 51617
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=51617&action=edit
Test case where a spurious/incorrect -Wmaybe-uninitialized warning is generated
Hi -- I noticed a regression in GCC 10 and GCC 11 related to `std::optional`.
The attached file, if compiled with `-O2 -Wall -std=c++17 -c` as options, will
warn incorrectly about uninitialized members on both GCC 10 and GCC 11 (I
haven't tried 9 yet but I think 8 & 9 are ok).
Note that the key element in the below code is the nested `struct Shared`. If
that is omitted, no warnings occur.
Attached code warns erroneously (GCC 10 & 11):
g++ -O2 -Wall -std=c++17 -c warn3.cpp
Attached code does not warn (nested struct omitted):
g++ -DNO_WARN -O2 -Wall -std=c++17 -c warn3.cpp
