From b76bfc09c3061d1ba7a28a9b88a5023b39446b14 Mon Sep 17 00:00:00 2001 From: "Pedro F. Giffuni" Date: Fri, 28 Dec 2012 19:02:28 +0000 Subject: [PATCH] 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. Upstream gcc has been slow to react to this issue and the author that submitted the patch is not interested in licensing the change to us, so I did an independent workaround for the issue. MFC after: 1 week --- contrib/gcc/dwarf2out.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/contrib/gcc/dwarf2out.c b/contrib/gcc/dwarf2out.c index 25a906bad445..453e653d2e5f 100644 --- a/contrib/gcc/dwarf2out.c +++ b/contrib/gcc/dwarf2out.c @@ -10812,9 +10812,9 @@ 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 sizes to Dtrace and gdb. */ + add_AT_unsigned (die, DW_AT_byte_size, (size > 0 ? size : 0)); } /* For a FIELD_DECL node which represents a bit-field, output an attribute