Re: [PATCH 0/6] DWARF Two Level Line Tables

[Doug Evans <dje@google.com>]

On Thu, Mar 12, 2015 at 12:58 PM, Doug Evans <dje@google.com> wrote:
> Hi.
>
> This patch set adds Two Level Line Tables support to gdb,
> as well as support for the DWARF 5 line table extensions.
>
> http://wiki.dwarfstd.org/index.php?title=TwoLevelLineTables
> http://www.dwarfstd.org/ShowIssue.php?issue=140906.1
> http://www.dwarfstd.org/ShowIssue.php?issue=140724.1
>
> The current version of the patch uses a gross hack because
> consumers of debug info, including gdb, are not aggressive
> enough in rejecting versions they don't understand.
> So that existing gdbs won't crash when given the new line table
> we create a DWARF 4 line header, and tuck the guts of the
> two line tables (logicals + actuals) in something that looks
> like a single entry.
> Fortunately 7.9 won't crash, so the plan is to hopefully do
> something more sensible.
>
> The patch has been regression tested with existing debug info,
> as well as the new two-level-line-table support on the google-4.9.x
> gcc branch, and the binutils users/ccoutant/two-level-line-tables branch.

I've committed the first four patches in this series,
which were just cleanups.

The remaining two patches add support for DWARF v5 line
tables as well as the proposed two level line tables.
Since stock gcc doesn't generate these yet my plan
is to hold off committing them for now.
I'm happy to commit them early if someone needs/wants me too.