Possible compiler issues

1

I came across this question on Stackoverflow, which asks about segmentation fault when using an optional class dummy argument. Although the question itself seems to have been solved (by changing class to type), this might be a possible compiler issue, so anyway I am reporting here:

A minimum reproducible example is like this:

module test_m
  implicit none

  type :: error_t
  end type

contains
  subroutine throw( stat )
    type(error_t), optional :: stat
  end
  subroutine test_throw( stat )
    class(error_t), optional :: stat
    call throw( stat )
  end
end

program main
  use test_m, only: error_t, test_throw
  implicit none
  type(error_t) :: stat

  call test_throw()       !! segfault(gfort-10.2 -O0 or no option)
  !call test_throw(stat)  !! ok
end

Segmentation fault goes away when compiling with optimization flags >= -O1.

2

Indeed, it looks like a GCC/gfortran problem. OP at StackOverflow should consider reporting it here:

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