PR fortran/102287 - optional allocatable array arguments (intent out) of derived types with allocatable components are not properly passed to subroutines
Commit Message
As nicely described in the PR, we mishandled the case of passing
optional allocatable DT arguments with allocatable components
when the INTENT was declared as INTENT(OUT), as we unconditionally
tried to deallocate these components even when the argument was not
present. The obvious solution is to wrap the code for deallocation
by a check for presence.
Regtested on x86_64-pc-linux-gnu. OK for mainline?
As this is a potentially nasty wrong-code bug, I'd like to backport
to at least 11-branch.
Thanks,
Harald
Fortran - fix handling of optional allocatable DT arguments with INTENT(OUT)
gcc/fortran/ChangeLog:
PR fortran/102287
* trans-expr.c (gfc_conv_procedure_call): Wrap deallocation of
allocatable components of optional allocatable derived type
procedure arguments with INTENT(OUT) into a presence check.
gcc/testsuite/ChangeLog:
PR fortran/102287
* gfortran.dg/intent_out_14.f90: New test.
Comments
Hello Harald,
> As nicely described in the PR, we mishandled the case of passing
> optional allocatable DT arguments with allocatable components
> when the INTENT was declared as INTENT(OUT), as we unconditionally
> tried to deallocate these components even when the argument was not
> present. The obvious solution is to wrap the code for deallocation
> by a check for presence.
Looks good.
> Regtested on x86_64-pc-linux-gnu. OK for mainline?
Sure!
> As this is a potentially nasty wrong-code bug, I'd like to backport
> to at least 11-branch.
OK for all open branches as far as you want to go.
Thanks for the patch!
Best regards
Thomas
@@ -6548,6 +6548,17 @@ gfc_conv_procedure_call (gfc_se * se, gfc_symbol * sym,
// deallocate the components first
tmp = gfc_deallocate_alloc_comp (fsym->ts.u.derived,
parmse.expr, e->rank);
+ /* But check whether dummy argument is optional. */
+ if (tmp != NULL_TREE
+ && fsym->attr.optional
+ && e->expr_type == EXPR_VARIABLE
+ && e->symtree->n.sym->attr.optional)
+ {
+ tree present;
+ present = gfc_conv_expr_present (e->symtree->n.sym);
+ tmp = build3_v (COND_EXPR, present, tmp,
+ build_empty_stmt (input_location));
+ }
if (tmp != NULL_TREE)
gfc_add_expr_to_block (&se->pre, tmp);
}
new file mode 100644
@@ -0,0 +1,24 @@
+! { dg-do run }
+! PR fortran/102287 - optional allocatable DT array arguments (intent out)
+
+module m
+ type t
+ integer, allocatable :: a
+ end type t
+contains
+ subroutine a (x, v)
+ type(t), optional, allocatable, intent(out) :: x(:)
+ type(t), optional, intent(out) :: v(:)
+ call b (x, v)
+ end subroutine a
+
+ subroutine b (y, w)
+ type(t), optional, allocatable, intent(out) :: y(:)
+ type(t), optional, intent(out) :: w(:)
+ end subroutine b
+end module m
+
+program p
+ use m
+ call a ()
+end