https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102043
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |ebotcazou at gcc dot gnu.org
--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
For this testcase the bogus ref is constructed by conv_array_index_offset:
/* Read the vector to get an index into info->descriptor. */
data = build_fold_indirect_ref_loc (input_location,
gfc_conv_array_data (desc));
index = gfc_build_array_ref (data, index, NULL);
where ultimatively gfc_conv_descriptor_data_get is what builds the
base the ARRAY_REF is applied to and thus GFC_TYPE_ARRAY_DATAPTR_TYPE
what is "wrong".
This type is built in gfc_get_array_type_bounds as
/* We define data as an array with the correct size if possible.
Much better than doing pointer arithmetic. */
if (stride)
rtype = build_range_type (gfc_array_index_type, gfc_index_zero_node,
int_const_binop (MINUS_EXPR, stride,
build_int_cst (TREE_TYPE
(stride), 1)));
else
rtype = gfc_array_range_type;
arraytype = build_array_type (etype, rtype);
arraytype = build_pointer_type (arraytype);
if (restricted)
arraytype = build_qualified_type (arraytype, TYPE_QUAL_RESTRICT);
GFC_TYPE_ARRAY_DATAPTR_TYPE (fat_type) = arraytype;
The issue might also be the source of "bogus" array bound warnings.
Note it might in the end be the issue that the middle-end lacks notion
of a stride for array accesses which the Fortran frontend emulates
by multiplying the index by the stride. When the stride is negative
then the idea to base all arrays on [0:] no longer works out. Note
that simply using an unknown TYPE_DOMAIN (aka NULL_TREE) doesn't
work either since we still assume that ARRAY_REFs can only have
positive indices.
Eric - does Ada have something like negative stride array accesses?
