[Bug fortran/65792] New: allocation of scalar elemental function with structure constructor fails

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65792

            Bug ID: 65792
           Summary: allocation of scalar elemental function with structure
                    constructor fails
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dominiq at lps dot ens.fr

The following test (extracted from the extended test in pr61831 comment 41)

program main
  implicit none

  integer, parameter :: n = 2

  type :: string_t
     character(LEN=1), dimension(:), allocatable :: chars
  end type string_t

  type :: string_container_t
     type(string_t) :: comp
  end type string_container_t

  type(string_t) :: prt_in, tmp, tmpa(n)
  type(string_container_t) :: tmpc, tmpca(n)
  integer :: i, j, k

  do i=1,16

     ! scalar elemental function with structure constructor
     prt_in = string_t(["D"])
     tmpc = new_prt_spec2 (string_container_t(prt_in))
     deallocate (prt_in%chars)
     deallocate(tmpc%comp%chars)

  end do

contains

  impure elemental function new_prt_spec2 (name) result (prt_spec)
    type(string_container_t), intent(in) :: name
    type(string_container_t) :: prt_spec
    prt_spec = name
  end function new_prt_spec2

end program main

fails at run time with

a.out(88248,0x7fff7a4fc300) malloc: *** mach_vm_map(size=18446603339116310528)
failed (error code=3)
*** error: can't allocate region
*** set a breakpoint in malloc_error_break to debug

Program received signal SIGSEGV: Segmentation fault - invalid memory reference.

For 4.6 up to 4.9.0, the failure is of the kind

a.out(45086) malloc: *** error for object 0x100201010: pointer being freed was
not allocated
*** set a breakpoint in malloc_error_break to debug