[Bug middle-end/56231] warning traces have bogus line information when using LTO

["rguenth at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56231

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> 2013-02-07 14:35:24 UTC ---
(In reply to comment #3)
> (In reply to comment #1)
> > Index: gcc/lto-streamer-in.c
> > ===================================================================
> > --- gcc/lto-streamer-in.c       (revision 195841)
> > +++ gcc/lto-streamer-in.c       (working copy)
> > @@ -164,13 +164,8 @@ lto_input_location (struct bitpack_d *bp
> >      data_in->current_col = bp_unpack_var_len_unsigned (bp);
> > 
> >    if (file_change)
> > -    {
> > -      if (prev_file)
> > -       linemap_add (line_table, LC_LEAVE, false, NULL, 0);
> > -
> > -      linemap_add (line_table, LC_ENTER, false, data_in->current_file,
> > -                  data_in->current_line);
> > -    }
> > +    linemap_add (line_table, LC_RENAME, false, data_in->current_file,
> > +                data_in->current_line);
> >    else if (line_change)
> >      linemap_line_start (line_table, data_in->current_line,
> > data_in->current_col);
> 
> Does not work because of
> 
> const struct line_map *
> linemap_add (struct line_maps *set, enum lc_reason reason,
>              unsigned int sysp, const char *to_file, linenum_type to_line)
> {
> ...
>   /* When we enter the file for the first time reason cannot be
>      LC_RENAME.  */
>   linemap_assert (!(set->depth == 0 && reason == LC_RENAME));
> 
> trying
> 
> Index: gcc/lto-streamer-in.c
> ===================================================================
> --- gcc/lto-streamer-in.c       (revision 195846)
> +++ gcc/lto-streamer-in.c       (working copy)
> @@ -165,11 +165,12 @@ lto_input_location (struct bitpack_d *bp
> 
>    if (file_change)
>      {
> -      if (prev_file)
> -       linemap_add (line_table, LC_LEAVE, false, NULL, 0);
> -
> -      linemap_add (line_table, LC_ENTER, false, data_in->current_file,
> -                  data_in->current_line);
> +      if (!prev_file)
> +       linemap_add (line_table, LC_ENTER, false, data_in->current_file,
> +                    data_in->current_line);
> +      else
> +       linemap_add (line_table, LC_RENAME, false, data_in->current_file,
> +                    data_in->current_line);
>      }
>    else if (line_change)
>      linemap_line_start (line_table, data_in->current_line,
> data_in->current_col);
> 
> we'll still eventually enter a file multiple times that way.  But let's see
> if it makes a difference...

Doesn't make a difference.