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From: "dmalcolm at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug analyzer/109014] -Wanalyzer-use-of-uninitialized-value seen in pcre2-10.42's pcre2test.c
Date: Fri, 03 Mar 2023 18:29:54 +0000	[thread overview]
Message-ID: <bug-109014-4-88xF7n890R@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-109014-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109014

--- Comment #1 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
I believe the issue here is that:

* display_properties partially initializes the "found" buffer, writing a -1
terminator at the end of the initialized part at:

    fv[m] = -1;

* display_properties then calls format_list_item, which tries to find the
terminator with:

 for (count = 0; ff[count] >= 0; count++) {

* -fanalyzer isn't smart enough to know that a -1 terminator has been written,
and simulates iterating past the end of the initialized region

and this is currently masked by the "sprintf" call, which in the absence of a
known_function implementation is currently assumed to potentially write to fv.

  reply	other threads:[~2023-03-03 18:29 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-03-03 18:24 [Bug analyzer/109014] New: " dmalcolm at gcc dot gnu.org
2023-03-03 18:29 ` dmalcolm at gcc dot gnu.org [this message]
2023-03-03 23:01 ` [Bug analyzer/109014] " cvs-commit at gcc dot gnu.org
2024-03-04 13:00 ` [Bug analyzer/109014] [13/14 Regression] " rguenth at gcc dot gnu.org
2024-03-08 15:38 ` law at gcc dot gnu.org
2024-05-21  9:14 ` [Bug analyzer/109014] [13/14/15 " jakub at gcc dot gnu.org

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