[Bug libfortran/81983] New: sanitizer detects undefined runtime error in libbacktrace

["zeccav at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81983

            Bug ID: 81983
           Summary: sanitizer detects undefined runtime error in
                    libbacktrace
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libfortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zeccav at gmail dot com
  Target Milestone: ---
              Host: x86_64-pc-linux-gnu
             Build: trunk 251201

! sanitizer detects runtime error in libbacktrace
! This file MUST NOT be compiled with -g option
! Must be compiled with -fsanitize=address,undefined and sanitized libgfortran
and libbacktrace
! libbacktrace/dwarf.c:2662:9: runtime error: null pointer passed as argument
2, which is declared to never be null
! dwarf.c:2662 "entry = bsearch (&pc, ddata->addrs, ddata->addrs_count,"
! ddata->addrs_count is probably zero so operation is undefined but harmless
! possible fix "entry=NULL; 
!               if(ddata->addrs_count) entry=bsearch (&pc, ddata->addrs,
ddata->addrs_count,"
      INTEGER, ALLOCATABLE :: arr(:)
      ALLOCATE (arr(5))
      ALLOCATE (arr(6))
      END