gdb: check for empty offsets vector in inherit_abstract_dies
When building GDB with clang and --enable-ubsan, I get:
UNRESOLVED: gdb.dwarf2/frame-inlined-in-outer-frame.exp: starti prompt
The cause being:
$ ./gdb --data-directory=data-directory -nx -q -readnow testsuite/outputs/gdb.dwarf2/frame-inlined-in-outer-frame/frame-inlined-in-outer-frame
Reading symbols from testsuite/outputs/gdb.dwarf2/frame-inlined-in-outer-frame/frame-inlined-in-outer-frame...
Expanding full symbols from testsuite/outputs/gdb.dwarf2/frame-inlined-in-outer-frame/frame-inlined-in-outer-frame...
/home/simark/src/binutils-gdb/gdb/dwarf2/read.c:11954:47: runtime error: applying non-zero offset 8 to null pointer
I found this to happen with ld-linux on at least Arch Linux and Ubuntu
22.04:
$ ./gdb --data-directory=data-directory -nx -q -readnow -iex "set debuginfod enabled on" /lib64/ld-linux-x86-64.so.2
Reading symbols from /lib64/ld-linux-x86-64.so.2...
Reading symbols from /home/simark/.cache/debuginfod_client/22bd7a2c03d8cfc05ef7092bfae5932223189bc1/debuginfo...
Expanding full symbols from /home/simark/.cache/debuginfod_client/22bd7a2c03d8cfc05ef7092bfae5932223189bc1/debuginfo...
/home/simark/src/binutils-gdb/gdb/dwarf2/read.c:11954:47: runtime error: applying non-zero offset 8 to null pointer
The problem happens when doing this:
sect_offset *offsetp = offsets.data () + 1
When `offsets` is an empty vector, `offsets.data ()` returns nullptr.
Fix it by wrapping that in a `!offsets.empty ()` check.
Change-Id: I6d29ba2fe80ba4308f68effd9c57d4ee8d67c29f
Approved-By: Tom Tromey <tom@tromey.com>
diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index cde7a5b..077af06 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -11949,17 +11949,22 @@ inherit_abstract_dies (struct die_info *die, struct dwarf2_cu *cu)
corresponding_abstract_child = corresponding_abstract_child->sibling;
}
- std::sort (offsets.begin (), offsets.end ());
- sect_offset *offsets_end = offsets.data () + offsets.size ();
- for (sect_offset *offsetp = offsets.data () + 1;
- offsetp < offsets_end;
- offsetp++)
- if (offsetp[-1] == *offsetp)
- complaint (_("Multiple children of DIE %s refer "
- "to DIE %s as their abstract origin"),
- sect_offset_str (die->sect_off), sect_offset_str (*offsetp));
+ if (!offsets.empty ())
+ {
+ std::sort (offsets.begin (), offsets.end ());
+ sect_offset *offsets_end = offsets.data () + offsets.size ();
+ for (sect_offset *offsetp = offsets.data () + 1;
+ offsetp < offsets_end;
+ offsetp++)
+ if (offsetp[-1] == *offsetp)
+ complaint (_("Multiple children of DIE %s refer "
+ "to DIE %s as their abstract origin"),
+ sect_offset_str (die->sect_off),
+ sect_offset_str (*offsetp));
+ }
sect_offset *offsetp = offsets.data ();
+ sect_offset *offsets_end = offsets.data () + offsets.size ();
die_info *origin_child_die = origin_die->child;
while (origin_child_die != nullptr && origin_child_die->tag != 0)
{
