gcc: avoid generating negative values to DW_AT_byte_size.

There is a bug in gcc (GCC/35998) where dwarf reports
sizes of unsigned -1 (0xffffffff).

On NetBSD this generated a faulty CTF entry which then
caused a segfault in ctfmerge. The issue was worked
around in NetBSD's Dtrace but since the issue originated
in gcc, it seems reasonable to fix it here.

Thanks to Christoph Mallon for pointing out a correct fix.
This commit is contained in:
christos 2013-01-17 20:01:37 +00:00
parent 62b158cdce
commit 8743a11216

View File

@ -10683,8 +10683,9 @@ add_byte_size_attribute (dw_die_ref die, tree tree_node)
/* Note that `size' might be -1 when we get to this point. If it is, that
indicates that the byte size of the entity in question is variable. We
have no good way of expressing this fact in Dwarf at the present time,
so just let the -1 pass on through. */
add_AT_unsigned (die, DW_AT_byte_size, size);
have no good way of expressing this fact in Dwarf at the present time.
GCC/35998: Avoid passing negative size values to Dtrace and gdb. */
add_AT_unsigned (die, DW_AT_byte_size, (size != (unsigned)-1 ? size : 0));
}
/* For a FIELD_DECL node which represents a bit-field, output an attribute