[Bug c++/102918] New: Undefined behaviour in regex header (uininitialized boolean)

[Bug c++/102918] New: Undefined behaviour in regex header (uininitialized boolean)

[camilotalero96 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102918

            Bug ID: 102918
           Summary: Undefined behaviour in regex header (uininitialized
                    boolean)
           Product: gcc
           Version: 11.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: camilotalero96 at hotmail dot com
  Target Milestone: ---

I am using undefined behaviour sanitizers and they are detecting a potential
bug in teh regex header, the specific report is:

`/usr/include/c++/11/bits/regex.h:909:15: runtime error: load of value 192,
which is not a valid value for type 'bool'`

Which does seem like the use of a potentially uninitialized boolean.

[Bug libstdc++/102918] Undefined behaviour in regex header (uininitialized boolean)

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102918

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2021-10-25
             Status|UNCONFIRMED                 |WAITING

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
std::sub_match only has one constructor, and it initializes the bool. The only
stores to that variable are literal treu or false values, or the result of a
boolean expression first != last. So there's no way I can see for the library
to cause this behaviour Are you sure you're not causing undefined behaviour in
your own code?

Have you tried building with -D_GLIBCXX_DEBUG to get runtime checks in
std::match_results.

Without more details there's nothing we can do here. The <regex> code looks
correct.

[Bug libstdc++/102918] Undefined behaviour in regex header (uininitialized boolean)

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102918

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |INVALID
             Status|WAITING                     |RESOLVED

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
No feedback or a testcase in over 2 years so closing as invalid. If you provide
a testcase we will be able to look into it but until then, closing as invalid.