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From: "burnus at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug fortran/105759] New: is_contiguous(zero_size_array(2:0))
 wrongly returns .true.
Date: Sat, 28 May 2022 15:48:53 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D105759

            Bug ID: 105759
           Summary: is_contiguous(zero_size_array(2:0)) wrongly returns
                    .true.
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: burnus at gcc dot gnu.org
  Target Milestone: ---

GCC and ifort both return T for the following code:

integer :: a(2)
print *, is_contiguous(a(2:1))
end


However, I think that should be F / .false. as F2018 has:

8.5.7 CONTIGUOUS attribute
...
An object is contiguous if it is
...
(7) a nonzero-sized array section (9.5.3) provided that
...


Disclaimer: I might have missed something.


If it is a bug, then we probably need to fix both the simplify.cc compile-t=
ime
and libgfortran run-time check.=