https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106731
kargl at gcc dot gnu.org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |kargl at gcc dot gnu.org
--- Comment #3 from kargl at gcc dot gnu.org ---
(In reply to federico from comment #0)
> A derived type that has user-defined I/O causes ICE on all gfortran versions
> 7 to 12.1.0, whenever it's being used as an automatic object.
>
> The error is at
>
>
> 63 | type(t) :: automatic(n)
> | 1
> internal compiler error: in gfc_trans_auto_array_allocation, at
> fortran/trans-array.cc:6617
>
> This does not happen if the derived type is allocated.
>
> Here's the simplest example:
>
> module causes_ice
> implicit none
>
> type :: t
> real(8) :: x
> contains
> procedure, private :: write_formatted
> generic :: write(formatted) => write_formatted
> end type t
>
> contains
>
> subroutine write_formatted(this, unit, iotype, v_list, iostat, iomsg)
> class(t), intent(in) :: this
> integer, intent(in) :: unit
> character(*), intent(in) :: iotype
> integer, intent(in) :: v_list(:)
> integer, intent(out) :: iostat
> character(*), intent(inout) :: iomsg
> write(unit, '(a)', iostat=iostat, iomsg=iomsg) 'dummy'
> end subroutine write_formatted
>
> end module causes_ice
>
> module use_t
> use causes_ice
> implicit none
>
> public :: automatic_alloc
>
> contains
>
> subroutine automatic_alloc(n)
> integer, intent(in) :: n
>
> ! Automatic array: ICE!
> type(t) :: automatic(n)
>
> ! Allocatable: works
> type(t), allocatable :: alloc(:)
> allocate(alloc(n))
>
> ! Do anything
> print *, 'n=',n,automatic(n)%x
>
> end subroutine automatic_alloc
>
> end module use_t
>
> program test
> use use_t
> call automatic_alloc(1)
> end program test
>
> I could find other DTIO-related bugs, but none seemed related with the
> allocation type.
You're hitting an assert() in trans-array.cc. It's unclear to me why the
assert() is there. If it is commented out, the code compiles and executes.
% git diff gcc/fortran/trans-array.cc | cat
diff --git a/gcc/fortran/trans-array.cc b/gcc/fortran/trans-array.cc
index 05134952db4..c5916aeee53 100644
--- a/gcc/fortran/trans-array.cc
+++ b/gcc/fortran/trans-array.cc
@@ -6614,7 +6614,7 @@ gfc_trans_auto_array_allocation (tree decl, gfc_symbol *
sym,
type = TREE_TYPE (type);
gcc_assert (!sym->attr.use_assoc);
- gcc_assert (!TREE_STATIC (decl));
+// gcc_assert (!TREE_STATIC (decl));
gcc_assert (!sym->module);
if (sym->ts.type == BT_CHARACTER
