http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54958
Bug #: 54958
Summary: Wrongly rejects ac-implied-DO variables which also
occur with INTENT(IN)
Classification: Unclassified
Product: gcc
Version: 4.8.0
Status: UNCONFIRMED
Keywords: rejects-valid
Severity: normal
Priority: P3
Component: fortran
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: bur...@gcc.gnu.org
gfortran rejects all four uses of "i" in the following program with
Error: Dummy argument 'i' with INTENT(IN) in variable definition context
(iterator variable) at (1)
However, it should only reject the use as variable in io-implied-do and in the
do-stmt and not the (ac-,data-)implied-do variable. Cf. IR 000076 at
ftp://ftp.nag.co.uk/sc22wg5/n1351-n1400/N1393.txt
g95, pathf95 and NAG properly handle this case, gfortran 4.1 to 4.8 doesn't.
subroutine test(i)
integer, intent(in) :: i
integer :: A(5)
! Valid: data-implied-do [WRONGLY rejected by gfortran]
DATA (A(i), i=1,5)/5*42/
! Valid: ac-implied-do [WRONGLY rejected by gfortran]
print *, [(i, i=1,5 )]
! Invalid: io-implied-do [OK: rejected by gfortran]
print *, (i, i=1,5 )
! Invalid: do-variable in a do-stmt [OK: rejected by gfortran]
do i = 1, 5
end do
end
>From the standard (F2008):
"C539 (R523) A nonpointer object with the INTENT (IN) attribute shall not
appear in a variable definition context (16.6.7)."
and in "16.6.7 Variable definition context":
"(4) a do-variable in a do-stmt or io-implied-do;"
The reason that a data-implied-do and ac-implied-do is allowed is given at
"16.4 Statement and construct entities":
"The name of a data-i-do-variable in a DATA statement or an ac-do-variable in
an array constructor has a scope of its data-implied-do or ac-implied-do. [...]
The appearance of a name as a data-i-do-variable of an implied DO in a DATA
statement or an ac-do-variable in an array constructor is not an implicit
declaration of a variable whose scope is the scoping unit that contains the
statement."
