https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127701
Bug ID: 127701
Summary: Contiguous parts of non-contiguous associate names are
not recognized as contiguous
Product: gcc
Version: 17.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: mikael at gcc dot gnu.org
Target Milestone: ---
Consider this example:
program prog
implicit none
integer, parameter :: n = 3
type :: t1
integer :: c1(n,n)
end type
type(t1), target :: x(n)
integer :: i, j
x = (/ (t1(reshape([ (i+j, j=1,n*n) ], [n,n])), i=1,n) /)
call sub(x)
contains
subroutine sub(y)
type(t1), target :: y(:)
integer, contiguous, pointer :: p(:)
associate(z => y)
p(1:n*n) => z(1)%c1
end associate
end subroutine
end program
It is rejected with the error:
>
> 16 | p(1:n*n) => z(1)%c1
> | 1
> Error: Rank remapping target must be rank 1 or simply contiguous at (1)
even if the target is clearly simply contiguous.
This is caused by the following code in the implementation of
gfc_is_simply_contiguous, that forwards the check from the associate symbol to
the associate target, without checking whether there are any subreferences to
the associate symbol:
6492 /* An associate variable may point to a non-contiguous target. */
6493 if (ar && ar->type == AR_FULL
6494 && sym->attr.associate_var && !sym->attr.contiguous
6495 && sym->assoc
6496 && sym->assoc->target)
6497 return gfc_is_simply_contiguous (sym->assoc->target, strict,
6498 permit_element);
