https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118396
Bug ID: 118396
Summary: Regression: -O1+ leads to reading uninitialized data
when virtual destructor is present
Product: gcc
Version: 15.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: carlosgalvezp at gmail dot com
Target Milestone: ---
Created attachment 60088
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=60088&action=edit
bug.cpp
Hi!
We are bumping our GCC install from e9fb6efa1cf542353fd44ddcbb5136344c463fd0 to
979ca3ba366da7177f427e049f67673ec3e35442, and this minimal example (attached)
no longer works. Reproducer on Compiler Explorer:
https://godbolt.org/z/3e6zfrMEW
When using -O1, I see garbage values being read. Valgrind confirms "Conditional
jump or move depends on uninitialised value(s)" when reading those values.
I have written a couple of comments of changes to the code that make it work as
expected. However I don't fully understand why that would be the case, I don't
believe there's UB in this snippet, but of course I could be missing something.
Looking forward to your feedback, thanks!
