Mark Wielaard <mjw(a)redhat.com> writes:
On Mon, 2011-03-07 at 09:56 -0800, Roland McGrath wrote:
> This produces a zero-length .debug_line section but a CU with a
> DW_AT_stmt_list attribute pointing to its start. That is invalid
> DWARF and hence a GCC bug. The place where DW_AT_stmt_list points
> must have a valid line information header, even if that says it's an
> empty table. I think what would be most correct here is to omit the
> DW_AT_stmt_list attribute entirely from that CU DIE.
Actually, the header is there, but there are no tables.
Reported with possible patch:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48045
But since the debug_line table header is actually there, dwarflint is
still not really happy. empty.o as produced by my patched gcc attached.
$ eu-dwarflint empty.o
warning: .debug_line: table 0: the file #1 `empty.c' is not used.
error: .debug_line: table 0: sequence of opcodes not terminated with
DW_LNE_end_sequence.
So maybe a better solution would be to just add a dummy end_sequence.
Well, missing DW_LNE_end_sequence is quite common, as I recall. Chances
are they are all cases of empty table with no opcodes whatsoever.
Perhaps I might supress the error for these cases.
PM