https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69650
--- Comment #14 from Manuel López-Ibáñez <manu at gcc dot gnu.org> ---
(In reply to rguent...@suse.de from comment #12)
> > This is an invalid linemarker. libcpp should ignore it completely and
> > behave as
> > if it was not present. It seems it is not doing that for some reason and
> > that
> > is messing up the line-table.
>
> Sure, but I don't see that 1048539 line number anywhere so it feels like
> sth is used uninitialized?
This was thoroughly analyzed by David above. The invalid linemarker causes an
invalid LC_LEAVE which then triggers an invalid line-number calculation.
Somehow, the code for handling the invalid linemarker is doing the wrong thing.
Perhaps this:
to_line = SOURCE_LINE (from, from[1].start_location);
should be
to_line = SOURCE_LINE (from, from->start_location);
But I don't understand what the following comment means (love those cryptic
comments in GCC!)
/* A TO_FILE of NULL is special - we use the natural values. */
if (error || to_file == NULL)
{
to_file = ORDINARY_MAP_FILE_NAME (from);
to_line = SOURCE_LINE (from, from[1].start_location);
sysp = ORDINARY_MAP_IN_SYSTEM_HEADER_P (from);
}
so it may be trying to do something else besides error-handling.
