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From: "redi at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/106093] [12/13 Regression] False positive -Wstringop-overflow with -O3 when resizing std::vector
Date: Mon, 16 Jan 2023 13:14:23 +0000 [thread overview]
Message-ID: <bug-106093-4-KJzlrQIREN@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-106093-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106093
--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #1)
> in particular the new allocated storage is processed but the old size is
> used?!
Yes, that seems correct.
We're resizing the vector from N to N+1 (where N happens to be 0). The new size
is greater than the existing capacity, so we allocate N+1 elements, then copy
the existing N elements into the new storage (which uses old_finish -
old_start).
Afterwards, we would actually construct the new element in the new storage, but
the warning happens while just copying the elements from the old storage to the
new.
next prev parent reply other threads:[~2023-01-16 13:14 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-26 21:31 [Bug c++/106093] New: [Regression] " aclopte at gmail dot com
2023-01-16 10:53 ` [Bug tree-optimization/106093] [12/13 Regression] " rguenth at gcc dot gnu.org
2023-01-16 13:14 ` redi at gcc dot gnu.org [this message]
2023-01-16 13:17 ` redi at gcc dot gnu.org
2023-05-08 12:24 ` [Bug tree-optimization/106093] [12/13/14 " rguenth at gcc dot gnu.org
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