On Sun, Jan 14, 2018 at 06:29:54AM -0800, H.J. Lu wrote:
> + if (TREE_CODE (field) == FIELD_DECL && DECL_PACKED (field))
> + {
> + tree field_type = TREE_TYPE (field);
> + unsigned int type_align = TYPE_ALIGN (field_type);
> + tree context = DECL_CONTEXT (field);
> + unsigned int record_align = TYPE_ALIGN (context);
> + if ((record_align % type_align) != 0)
> + return context;
> + type_align /= BITS_PER_UNIT;
> + unsigned HOST_WIDE_INT field_off
> + = (tree_to_uhwi (DECL_FIELD_OFFSET (field))
> + + (tree_to_uhwi (DECL_FIELD_BIT_OFFSET (field))
> + / BITS_PER_UNIT));
This has the same bug I've just created PR83844 for, you can't assume
DECL_FIELD_OFFSET is INTEGER_CST that fits into UHWI, and also we have
byte_position wrapper that should be used to compute the offset from
DECL_FIELD_*OFFSET.
Jakub
