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

["rguenther at suse dot de" <gcc-bugzilla at gcc dot gnu dot org>]

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

--- Comment #13 from rguenther at suse dot de <rguenther at suse dot de> 2013-02-12 11:11:11 UTC ---
On Tue, 12 Feb 2013, matt at use dot net wrote:

> 
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56231
> 
> --- Comment #12 from Matt Hargett <matt at use dot net> 2013-02-12 02:02:33 UTC ---
> looking at the patch for merging elsewhere, I noticed that
> 
>  location_t
>  lto_input_location (struct bitpack_d *bp, struct data_in *data_in)
>  {
> +  static const char *current_file;
> +  static int current_line;
> +  static int current_col;
>    bool file_change, line_change, column_change;
>    unsigned len;
> -  bool prev_file = data_in->current_file != NULL;
> +  bool prev_file = current_file != NULL;
> 
> 
> current_file is potentially of unknown value on the comparison in the last
> line, right? or is there some static const initialization rule that implicitly
> initializes it to 0?

Yes, all statics are zero-initialized.

As for the testcase, the LTO testsuite harness does not support
dg-warning and friends so it's not possible to add a meaningful
testcase.