https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77390
Bug ID: 77390
Summary: generates INDIRECT_REF of void type
Product: gcc
Version: 6.2.0
Status: UNCONFIRMED
Keywords: wrong-code
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: rguenth at gcc dot gnu.org
Target Milestone: ---
At trans-expr.c:5523 we have
if (e->ts.type == BT_DERIVED && fsym && fsym->ts.type == BT_CLASS)
{
/* The derived type is passed to gfc_deallocate_alloc_comp.
Therefore, class actuals can handled correctly but derived
types passed to class formals need the _data component. */
tmp = gfc_class_data_get (tmp);
if (!CLASS_DATA (fsym)->attr.dimension)
tmp = build_fold_indirect_ref_loc (input_location, tmp);
where the build_fold_indirect_ref_loc, for the testcase
gfortran.dg/submodule_6.f08 at least ends up building an INDIRECT_REF of
void type as tmp is a generic pointer (void *):
(gdb) p debug_tree (tmp)
<component_ref 0x7ffff669b360
type <pointer_type 0x7ffff68a02a0
type <void_type 0x7ffff68a0150 void VOID
align 8 symtab 0 alias set -1 canonical type 0x7ffff68a0150
pointer_to_this <pointer_type 0x7ffff68a02a0>>
public unsigned DI
size <integer_cst 0x7ffff6887bb8 constant 64>
unit size <integer_cst 0x7ffff6887bd0 constant 8>
align 64 symtab 0 alias set -1 canonical type 0x7ffff68a02a0
pointer_to_this <pointer_type 0x7ffff68a6a80>>
arg 0 <indirect_ref 0x7ffff6695c60
type <record_type 0x7ffff6696000 __class__STAR_t type_4 BLK
the resulting INDIRECT_REF:
<indirect_ref 0x7ffff6695c80
type <void_type 0x7ffff68a0150 void VOID
align 8 symtab 0 alias set -1 canonical type 0x7ffff68a0150
pointer_to_this <pointer_type 0x7ffff68a02a0>>
arg 0 <component_ref 0x7ffff669b360
type <pointer_type 0x7ffff68a02a0 type <void_type 0x7ffff68a0150 void>
public unsigned DI
this indirect ref is then further sub-setted by COMPONENT_REFs which means
the FE knows the record type it intends to use here.
This confuses the middle-end quite a bit and I intend to add checking that
this doesn't happen.
The following should catch this at the root (the ! type because I don't
know whether we're lazily setting type anywhere)
Index: gcc/tree.c
===================================================================
--- gcc/tree.c (revision 239773)
+++ gcc/tree.c (working copy)
@@ -4405,6 +4407,7 @@ build1_stat (enum tree_code code, tree t
/* Whether a dereference is readonly has nothing to do with whether
its operand is readonly. */
TREE_READONLY (t) = 0;
+ gcc_assert (! type || ! VOID_TYPE_P (type));
break;
case ADDR_EXPR:
