[Bug fortran/91544] New: When initializing allocatable character array get "Error: size of variable 'A.0' is too large"

[urbanjost at comcast dot net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91544

            Bug ID: 91544
           Summary: When initializing allocatable character array get
                    "Error: size of variable 'A.0' is too large"
           Product: gcc
           Version: 7.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: urbanjost at comcast dot net
  Target Milestone: ---

If use a non-constant integer as the length for an allocatable character
variable array get a confusing error message.

If the integer LINE_LENGTH is a PARAMETER it works.

A work-around where the array is first allocated as a zero-size array
and then included in the assignment works.

Otherwise get an odd compile-time error about "A.0" being too large.

program testit
implicit none
integer                      :: line_length=50
character(len=:),allocatable :: test_in(:)

#ifdef BAD
   test_in=[ character(len=line_length) ::  'aaa','bb' ]
#else
   allocate(character(len=line_length) :: test_in(0))
   test_in=[character(len=line_length) :: test_in,'aaa','bb']
#endif
   write(*,*)test_in
end program testit

gfortran -UBAD xx.F90
 aaa                                               bb                           
gfortran -DBAD xx.F90
xx.f90:4:0:

    test_in=[ character(len=line_length) ::  'this is a test' ]

Error: size of variable 'A.0' is too large