https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96047
Bug ID: 96047
Summary: Bogus unitialized warning for derived type with
allocatable components
Product: gcc
Version: 10.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: jellby at yahoo dot com
Target Milestone: ---
The program below gives a bogus warning when compiling with -O0, but not with
-O1 or higher:
$ gfortran a.f90 -Wall -O0
a.f90:9:0:
call new(a,3)
Warning: ‘a.dim[0].ubound’ may be used uninitialized in this function
[-Wmaybe-uninitialized]
a.f90:9:0: Warning: ‘a.dim[0].lbound’ may be used uninitialized in this
function [-Wmaybe-uninitialized]
The warning goes away if the "allocate(a(0))" line is uncommented, but that
should not be necessary, because the argument is "intent(out)", so it it must
be allocated in the subroutine.
$ cat a.f90
program test
implicit none
type foo
real, allocatable :: c(:)
end type foo
type(foo), allocatable :: a(:)
!allocate(a(0))
call new(a,3)
contains
subroutine new(m,n)
type(foo), allocatable, intent(out) :: m(:)
integer, intent(in) :: n
integer :: i
allocate(m(n))
do i=1,n
allocate(m(i)%c(n))
end do
end subroutine new
end program
