[Bug libstdc++/106607] Regex integer overflow on large backreference value

["cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106607

--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-10 branch has been updated by Jonathan Wakely
<redi@gcc.gnu.org>:

https://gcc.gnu.org/g:fab3692a2cf961b7364d7f77dd976ba0e4f752b7

commit r10-11467-gfab3692a2cf961b7364d7f77dd976ba0e4f752b7
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Mon Aug 22 15:16:16 2022 +0100

    libstdc++: Check for overflow in regex back-reference [PR106607]

    Currently we fail to notice integer overflow when parsing a
    back-reference expression, or when converting the parsed result from
    long to int. This changes the result to be int, so no conversion is
    needed, and uses the overflow-checking built-ins to detect an
    out-of-range back-reference.

    libstdc++-v3/ChangeLog:

            PR libstdc++/106607
            * include/bits/regex_compiler.tcc (_Compiler::_M_cur_int_value):
            Use built-ins to check for integer overflow in back-reference
            number.
            * testsuite/28_regex/basic_regex/106607.cc: New test.

    (cherry picked from commit 1b09eea33f2bf9d1eae73b25cc25efb05ea1dc3f)