[Bug fortran/103970] New: Multi-image co_broadcast of derived type with allocatable components fails

[damian at sourceryinstitute dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103970

            Bug ID: 103970
           Summary: Multi-image co_broadcast of derived type with
                    allocatable components fails
           Product: gcc
           Version: 11.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: damian at sourceryinstitute dot org
  Target Milestone: ---

Using gfortran 11.2.0 installed by Homebrew on macOS 12.0.1 to compile the code
below and link against OpenCoarrays 2.9.2 built with MPICH 3.2.0 results in
printing "Test failed." when executed in multiple images.

  implicit none

  type foo_t
    integer i
    integer, allocatable :: j
  end type

  type(foo_t) foo
  integer, parameter :: source_image = 1

  if (this_image() == source_image)  then
    foo = foo_t(2,3)
  else
    allocate(foo%j)
  end if
  call co_broadcast(foo, source_image)

  if ((foo%i /= 2) .or. (foo%j /= 3))  error stop "Test failed."
  sync all
  print *, "Test passed."

end

This bug is also summarized in OpenCoarrays issue 727 at
https://github.com/sourceryinstitute/OpenCoarrays/issues/727, where Andre
Vehreschild confirms that the problem is a compiler bug.