https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67679
Bug ID: 67679
Summary: -Wunitialized reports on compiler generated variables
Product: gcc
Version: 5.2.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: Joost.VandeVondele at mat dot ethz.ch
Target Milestone: ---
With gcc 5.2 I see:
> gfortran -c -g -O2 -Wuninitialized -cpp bug.f90
bug.f90:15:0:
DIMENSION(:, :, :) :: work
^
Warning: ‘work.dim[2].stride’ may be used uninitialized in this function
[-Wmaybe-uninitialized]
bug.f90:15:0: Warning: ‘work.dim[1].stride’ may be used uninitialized in this
function [-Wmaybe-uninitialized]
bug.f90:15:0: Warning: ‘work.offset’ may be used uninitialized in this function
[-Wmaybe-uninitialized]
where the problem is that compiler generated variables appear in the output.
(.stride happens x178, .ubound x 111 and .lbound x9 in a CP2K compile).
Some strange forms (not in this testcase) include also :
‘MEM[(integer(kind=4)[2] *)&dim1swp_stat][1]’ may be used uninitialized in this
function
should I try to reduce a testcase for the latter ?
testcase:
> cat bug.f90
MODULE memory_utilities
INTEGER, PARAMETER :: dp=8, dp_size=8
CHARACTER(len=*), PARAMETER, PRIVATE :: moduleN = 'memory_utilities'
CONTAINS
SUBROUTINE reallocate_c3(p,lb1_new,ub1_new,lb2_new,ub2_new,lb3_new,ub3_new)
COMPLEX(KIND=dp), DIMENSION(:, :, :), &
POINTER :: p
INTEGER, INTENT(IN) :: lb1_new, ub1_new, lb2_new, &
ub2_new, lb3_new, ub3_new
CHARACTER(LEN=*), PARAMETER :: routineN = 'reallocate_c3', &
routineP = moduleN//':'//routineN
COMPLEX(KIND=dp), PARAMETER :: zero = (0.0_dp,0.0_dp)
INTEGER, PARAMETER :: t_size = 2*dp_size
COMPLEX(KIND=dp), ALLOCATABLE, &
DIMENSION(:, :, :) :: work
INTEGER :: istat, lb1, lb1_old, lb2, lb2_old, lb3, lb3_old, &
ub1, ub1_old, ub2, ub2_old, ub3, ub3_old
IF (ASSOCIATED(p)) THEN
lb1_old = LBOUND(p,1)
ub1_old = UBOUND(p,1)
lb2_old = LBOUND(p,2)
ub2_old = UBOUND(p,2)
lb3_old = LBOUND(p,3)
ub3_old = UBOUND(p,3)
lb1 = MAX(lb1_new,lb1_old)
ub1 = MIN(ub1_new,ub1_old)
lb2 = MAX(lb2_new,lb2_old)
ub2 = MIN(ub2_new,ub2_old)
lb3 = MAX(lb3_new,lb3_old)
ub3 = MIN(ub3_new,ub3_old)
ALLOCATE (work(lb1:ub1,lb2:ub2,lb3:ub3),STAT=istat)
IF (istat /= 0) THEN
CALL stop_memory(routineN,moduleN,__LINE__,&
"work",t_size*(ub1-lb1+1)*&
(ub2-lb2+1)*&
(ub3-lb3+1))
END IF
work(lb1:ub1,lb2:ub2,lb3:ub3) = p(lb1:ub1,lb2:ub2,lb3:ub3)
DEALLOCATE (p)
END IF
ALLOCATE (p(lb1_new:ub1_new,lb2_new:ub2_new,lb3_new:ub3_new),STAT=istat)
IF (istat /= 0) THEN
CALL stop_memory(routineN,moduleN,__LINE__,&
"p",t_size*(ub1_new-lb1_new+1)*&
(ub2_new-lb2_new+1)*&
(ub3_new-lb3_new+1))
END IF
p(:,:,:) = zero
IF (ASSOCIATED(p).AND.ALLOCATED(work)) THEN
p(lb1:ub1,lb2:ub2,lb3:ub3) = work(lb1:ub1,lb2:ub2,lb3:ub3)
DEALLOCATE (work)
END IF
END SUBROUTINE reallocate_c3
END MODULE memory_utilities
