[Bug sanitizer/82353] New: runtime ubsan crash

[babokin at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82353

            Bug ID: 82353
           Summary: runtime ubsan crash
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: sanitizer
          Assignee: unassigned at gcc dot gnu.org
          Reporter: babokin at gmail dot com
                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: ---

Created attachment 42255
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=42255&action=edit
reduced test case

GCC trunk, rev 253244, x86_64.

> g++ -std=c++11 -fsanitize=undefined -fno-sanitize-recover=undefined -w -O2 ff.cpp dd.cpp -o out
> ./out
ff.cpp:20:27: runtime error: pointer index expression with base 0x0000006022f0
overflowed to 0x000000602300

Test case was reduced from a larger UB-free program.

I failed to reduce test case to a single file reproducer.