[Bug sanitizer/113092] New: SanitizerTool: CHECK failed: ubsan_value.cpp:69 "((getType().isSignedIntegerTy())) != (0)" (0x0, 0x0) with _BitInt()

[Bug sanitizer/113092] New: SanitizerTool: CHECK failed: ubsan_value.cpp:69 "((getType().isSignedIntegerTy())) != (0)" (0x0, 0x0) with _BitInt()

[zsojka at seznam dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113092

            Bug ID: 113092
           Summary: SanitizerTool: CHECK failed: ubsan_value.cpp:69
                    "((getType().isSignedIntegerTy())) != (0)" (0x0, 0x0)
                    with _BitInt()
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: sanitizer
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zsojka at seznam dot cz
                CC: dodji at gcc dot gnu.org, dvyukov at gcc dot gnu.org,
                    jakub at gcc dot gnu.org, kcc at gcc dot gnu.org, marxin at gcc dot gnu.org
  Target Milestone: ---
              Host: x86_64-pc-linux-gnu
            Target: x86_64-pc-linux-gnu

Created attachment 56909
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=56909&action=edit
reduced testcase

Using UBsan with _BitInt() fails at runtime:
$ x86_64-pc-linux-gnu-gcc -fsanitize=undefined testcase.c
$ ./a.out 
SanitizerTool: CHECK failed: ubsan_value.cpp:69
"((getType().isSignedIntegerTy())) != (0)" (0x0, 0x0) (tid=9442)


$ x86_64-pc-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=/repo/gcc-trunk/binary-latest-amd64/bin/x86_64-pc-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-r14-6742-20231220113252-gbe9e8de6284-checking-yes-rtl-df-extra-nobootstrap-amd64/bin/../libexec/gcc/x86_64-pc-linux-gnu/14.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /repo/gcc-trunk//configure --enable-languages=c,c++
--enable-valgrind-annotations --disable-nls --enable-checking=yes,rtl,df,extra
--disable-bootstrap --with-cloog --with-ppl --with-isl
--build=x86_64-pc-linux-gnu --host=x86_64-pc-linux-gnu
--target=x86_64-pc-linux-gnu --with-ld=/usr/bin/x86_64-pc-linux-gnu-ld
--with-as=/usr/bin/x86_64-pc-linux-gnu-as --disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-r14-6742-20231220113252-gbe9e8de6284-checking-yes-rtl-df-extra-nobootstrap-amd64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 14.0.0 20231220 (experimental) (GCC)

[Bug sanitizer/113092] _BitInt of shift vs ubsan

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113092

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Looks like this fails even in clang trunk:
UndefinedBehaviorSanitizer: CHECK failed: ubsan_value.cpp:86 "((0 &&
"unexpected bit width")) != (0)" (0x0, 0x0) (tid=1)

[Bug sanitizer/113092] _BitInt of shift vs ubsan

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113092

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
           See Also|                            |https://github.com/llvm/llv
                   |                            |m-project/issues/76113
   Last reconfirmed|                            |2023-12-21
     Ever confirmed|0                           |1

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Confirmed, Filed it upstream too:
https://github.com/llvm/llvm-project/issues/76113

[Bug sanitizer/113092] _BitInt of shift vs ubsan

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113092

--- Comment #3 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jakub Jelinek <jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:0e7f5039c52a020c3ed5f18a2b3ee1fb42b78f62

commit r14-6778-g0e7f5039c52a020c3ed5f18a2b3ee1fb42b78f62
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Thu Dec 21 11:14:55 2023 +0100

    ubsan: Add workaround for missing bitint libubsan support for shifts
[PR113092]

    libubsan still doesn't support bitints, so ubsan contains a workaround and
    emits value 0 and TK_Unknown kind for those.  If shift second operand has
    the large/huge _BitInt type, this results in internal errors in libubsan
    though, so the following patch provides a temporary workaround for that
    - in the rare case where the last operand has _BitInt type wider than
    __int128 (or long long on 32-bit arches), it will pretend the shift count
    has that type saturated to its range.  IMHO better than crashing in
    the library.  If the value fits into the __int128 (or long long) range,
    it will be printed correctly (just print that it has __int128/long long
    type rather than say _BitInt(255)), if it doesn't, user will at least
    know that it is a very large negative or very large positive value.

    2023-12-21  Jakub Jelinek  <jakub@redhat.com>

            PR sanitizer/113092
            * c-ubsan.cc (ubsan_instrument_shift): Workaround for missing
            ubsan _BitInt support for the shift count.

            * gcc.dg/ubsan/bitint-4.c: New test.

[Bug sanitizer/113092] _BitInt of shift vs ubsan

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113092

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Worked around for now (till libubsan has proper _BitInt support).

[Bug sanitizer/113092] _BitInt of shift vs ubsan

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113092

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
             Status|NEW                         |RESOLVED

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
.