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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
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D109014

--- 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] =3D -1;

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

 for (count =3D 0; ff[count] >=3D 0; count++) {

* -fanalyzer isn't smart enough to know that a -1 terminator has been writt=
en,
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.=