https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105658
Bug ID: 105658
Summary: Passing array component to unlimited polymorphic
routine passes wrong slice
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: zed.three at gmail dot com
Target Milestone: ---
The following program:
program f
implicit none
type :: foo
integer :: member1
integer :: member2
end type foo
type(foo), dimension(3) :: thing = [foo(1, 2), foo(3, 4), foo(5, 6)]
call print_poly(thing%member1)
call print_int(thing%member1)
contains
subroutine print_poly(array)
class(*), dimension(:), intent(in) :: array
select type(array)
type is (integer)
print*, array
end select
end subroutine
subroutine print_int(array)
integer, dimension(:), intent(in) :: array
print*, array
end subroutine
end program f
prints:
1 2 3
1 3 5
when we would expect:
1 3 5
1 3 5
Adding `-fcheck=all`, we get the warning "Fortran runtime warning: An array
temporary was created" _only_ for the call to `print_int`.
Adding an extra set of parentheses to the `print_poly` call (`call
print_poly((thing%member1))` gives the expected behaviour, I guess because it's
forcing an array temporary?
This behaviour is present in 4.9.4 through to the trunk currently available on
Compiler Explorer
((Compiler-Explorer-Build-gcc-7da9a089608b0ca09683332ce014fb6184842724-binutils-2.38)
13.0.0 20220518 (experimental))
